Package org.rocksdb

Class RocksDB

java.lang.Object

org.rocksdb.AbstractNativeReference

org.rocksdb.AbstractImmutableNativeReference

org.rocksdb.RocksObject

org.rocksdb.RocksDB

All Implemented Interfaces:

AutoCloseable

Direct Known Subclasses:

OptimisticTransactionDB, TransactionDB, TtlDB

public class RocksDB
extends RocksObject

A RocksDB is a persistent ordered map from keys to values. It is safe for concurrent access from multiple threads without any external synchronization. All methods of this class could potentially throw RocksDBException, which indicates sth wrong at the RocksDB library side and the call failed.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	RocksDB.CountAndSize
static class	RocksDB.LiveFiles
static class	RocksDB.Version

Field Summary

Fields

Modifier and Type	Field	Description
static final byte[]	DEFAULT_COLUMN_FAMILY
static final int	NOT_FOUND
protected DBOptionsInterface<?>	options_

Fields inherited from class org.rocksdb.RocksObject

nativeHandle_

Fields inherited from class org.rocksdb.AbstractImmutableNativeReference

owningHandle_

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	RocksDB(long nativeHandle)	Private constructor.

Method Summary

Modifier and Type	Method	Description
void	cancelAllBackgroundWork(boolean wait)	This function will cancel all currently running background processes.
void	clipColumnFamily(ColumnFamilyHandle columnFamilyHandle, byte[] beginKey, byte[] endKey)	ClipColumnFamily() will clip the entries in the CF according to the range [begin_key, end_key).
void	close()	This is similar to closeE() except that it silently ignores any errors.
void	closeE()	This is similar to close() except that it throws an exception if any error occurs.
List<String>	compactFiles(CompactionOptions compactionOptions, List<String> inputFileNames, int outputLevel, int outputPathId, CompactionJobInfo compactionJobInfo)	Takes a list of files specified by file names and compacts them to the specified level.
List<String>	compactFiles(CompactionOptions compactionOptions, ColumnFamilyHandle columnFamilyHandle, List<String> inputFileNames, int outputLevel, int outputPathId, CompactionJobInfo compactionJobInfo)	Takes a list of files specified by file names and compacts them to the specified level.
void	compactRange()	Range compaction of database.
void	compactRange(byte[] begin, byte[] end)	Range compaction of database.
void	compactRange(ColumnFamilyHandle columnFamilyHandle)	Range compaction of column family.
void	compactRange(ColumnFamilyHandle columnFamilyHandle, byte[] begin, byte[] end)	Range compaction of column family.
void	compactRange(ColumnFamilyHandle columnFamilyHandle, byte[] begin, byte[] end, CompactRangeOptions compactRangeOptions)	Range compaction of column family.
void	continueBackgroundWork()	Resumes background work which was suspended by previously calling pauseBackgroundWork()
List<ColumnFamilyHandle>	createColumnFamilies(List<ColumnFamilyDescriptor> columnFamilyDescriptors)	Bulk create column families with the same column family options.
List<ColumnFamilyHandle>	createColumnFamilies(ColumnFamilyOptions columnFamilyOptions, List<byte[]> columnFamilyNames)	Bulk create column families with the same column family options.
ColumnFamilyHandle	createColumnFamily(ColumnFamilyDescriptor columnFamilyDescriptor)	Creates a new column family with the name columnFamilyName and allocates a ColumnFamilyHandle within an internal structure.
ColumnFamilyHandle	createColumnFamilyWithImport(ColumnFamilyDescriptor columnFamilyDescriptor, ImportColumnFamilyOptions importColumnFamilyOptions, List<ExportImportFilesMetaData> metadatas)
ColumnFamilyHandle	createColumnFamilyWithImport(ColumnFamilyDescriptor columnFamilyDescriptor, ImportColumnFamilyOptions importColumnFamilyOptions, ExportImportFilesMetaData metadata)	Creates a new column family with the name columnFamilyName and import external SST files specified in `metadata` allocates a ColumnFamilyHandle within an internal structure.
void	delete(byte[] key)	Delete the database entry (if any) for "key".
void	delete(byte[] key, int offset, int len)	Delete the database entry (if any) for "key".
void	delete(ColumnFamilyHandle columnFamilyHandle, byte[] key)	Delete the database entry (if any) for "key".
void	delete(ColumnFamilyHandle columnFamilyHandle, byte[] key, int offset, int len)	Delete the database entry (if any) for "key".
void	delete(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpt, byte[] key)	Delete the database entry (if any) for "key".
void	delete(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpt, byte[] key, int offset, int len)	Delete the database entry (if any) for "key".
void	delete(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpt, ByteBuffer key)	Delete the database entry (if any) for "key".
void	delete(WriteOptions writeOpt, byte[] key)	Delete the database entry (if any) for "key".
void	delete(WriteOptions writeOpt, byte[] key, int offset, int len)	Delete the database entry (if any) for "key".
void	delete(WriteOptions writeOpt, ByteBuffer key)	Delete the database entry (if any) for "key".
void	deleteFile(String name)	Delete the file name from the db directory and update the internal state to reflect that.
void	deleteFilesInRanges(ColumnFamilyHandle columnFamily, List<byte[]> ranges, boolean includeEnd)	Delete files in multiple ranges at once.
void	deleteRange(byte[] beginKey, byte[] endKey)	Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey".
void	deleteRange(ColumnFamilyHandle columnFamilyHandle, byte[] beginKey, byte[] endKey)	Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey".
void	deleteRange(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpt, byte[] beginKey, byte[] endKey)	Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey".
void	deleteRange(WriteOptions writeOpt, byte[] beginKey, byte[] endKey)	Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey".
void	destroyColumnFamilyHandle(ColumnFamilyHandle columnFamilyHandle)	Deletes native column family handle of given ColumnFamilyHandle Java object and removes reference from ownedColumnFamilyHandles.
static void	destroyDB(String path, Options options)	Static method to destroy the contents of the specified database.
void	disableFileDeletions()	Prevent file deletions.
protected void	disposeInternal(long handle)
void	dropColumnFamilies(List<ColumnFamilyHandle> columnFamilies)
void	dropColumnFamily(ColumnFamilyHandle columnFamilyHandle)	Drops the column family specified by columnFamilyHandle.
void	enableAutoCompaction(List<ColumnFamilyHandle> columnFamilyHandles)	Enable automatic compactions for the given column families if they were previously disabled.
void	enableFileDeletions()	EnableFileDeletions will only enable file deletion after it's been called at least as many times as DisableFileDeletions(), enabling the two methods to be called by two threads concurrently without synchronization -- i.e., file deletions will be enabled only after both threads call EnableFileDeletions()
void	endTrace()	Stop tracing DB operations.
void	flush(FlushOptions flushOptions)	Flush all memory table data.
void	flush(FlushOptions flushOptions, List<ColumnFamilyHandle> columnFamilyHandles)	Flushes multiple column families.
void	flush(FlushOptions flushOptions, ColumnFamilyHandle columnFamilyHandle)	Flush all memory table data.
void	flushWal(boolean sync)	Flush the WAL memory buffer to the file.
byte[]	get(byte[] key)	The simplified version of get which returns a new byte array storing the value associated with the specified input key if any.
int	get(byte[] key, byte[] value)	Get the value associated with the specified key within column family*
byte[]	get(byte[] key, int offset, int len)	The simplified version of get which returns a new byte array storing the value associated with the specified input key if any.
int	get(byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Get the value associated with the specified key within column family*
byte[]	get(ColumnFamilyHandle columnFamilyHandle, byte[] key)	The simplified version of get which returns a new byte array storing the value associated with the specified input key if any.
int	get(ColumnFamilyHandle columnFamilyHandle, byte[] key, byte[] value)	Get the value associated with the specified key within column family.
byte[]	get(ColumnFamilyHandle columnFamilyHandle, byte[] key, int offset, int len)	The simplified version of get which returns a new byte array storing the value associated with the specified input key if any.
int	get(ColumnFamilyHandle columnFamilyHandle, byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Get the value associated with the specified key within column family.
byte[]	get(ColumnFamilyHandle columnFamilyHandle, ReadOptions opt, byte[] key)	The simplified version of get which returns a new byte array storing the value associated with the specified input key if any.
int	get(ColumnFamilyHandle columnFamilyHandle, ReadOptions opt, byte[] key, byte[] value)	Get the value associated with the specified key within column family.
byte[]	get(ColumnFamilyHandle columnFamilyHandle, ReadOptions opt, byte[] key, int offset, int len)	The simplified version of get which returns a new byte array storing the value associated with the specified input key if any.
int	get(ColumnFamilyHandle columnFamilyHandle, ReadOptions opt, byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Get the value associated with the specified key within column family.
int	get(ColumnFamilyHandle columnFamilyHandle, ReadOptions opt, ByteBuffer key, ByteBuffer value)	Get the value associated with the specified key within column family.
byte[]	get(ReadOptions opt, byte[] key)	The simplified version of get which returns a new byte array storing the value associated with the specified input key if any.
int	get(ReadOptions opt, byte[] key, byte[] value)	Get the value associated with the specified key.
byte[]	get(ReadOptions opt, byte[] key, int offset, int len)	The simplified version of get which returns a new byte array storing the value associated with the specified input key if any.
int	get(ReadOptions opt, byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Get the value associated with the specified key.
int	get(ReadOptions opt, ByteBuffer key, ByteBuffer value)	Get the value associated with the specified key within column family.
long	getAggregatedLongProperty(String property)	Return sum of the getLongProperty of all the column families
RocksDB.CountAndSize	getApproximateMemTableStats(ColumnFamilyHandle columnFamilyHandle, Range range)	This method is similar to getApproximateSizes(ColumnFamilyHandle, List, SizeApproximationFlag...), except that it returns approximate number of records and size in memtables.
RocksDB.CountAndSize	getApproximateMemTableStats(Range range)	This method is similar to getApproximateSizes(ColumnFamilyHandle, List, SizeApproximationFlag...), except that it returns approximate number of records and size in memtables.
long[]	getApproximateSizes(List<Range> ranges, SizeApproximationFlag... sizeApproximationFlags)	Get the approximate file system space used by keys in each range for the default column family.
long[]	getApproximateSizes(ColumnFamilyHandle columnFamilyHandle, List<Range> ranges, SizeApproximationFlag... sizeApproximationFlags)	Get the approximate file system space used by keys in each range.
ColumnFamilyMetaData	getColumnFamilyMetaData()	Obtains the meta data of the default column family of the DB.
ColumnFamilyMetaData	getColumnFamilyMetaData(ColumnFamilyHandle columnFamilyHandle)	Obtains the meta data of the specified column family of the DB.
MutableDBOptions.MutableDBOptionsBuilder	getDBOptions()	Get the database options
ColumnFamilyHandle	getDefaultColumnFamily()	Gets the handle for the default column family
Env	getEnv()	Get the Env object from the DB
long	getLatestSequenceNumber()	The sequence number of the most recent transaction.
RocksDB.LiveFiles	getLiveFiles()	Retrieve the list of all files in the database after flushing the memtable.
RocksDB.LiveFiles	getLiveFiles(boolean flushMemtable)	Retrieve the list of all files in the database.
List<LiveFileMetaData>	getLiveFilesMetaData()	Gets a list of all table files metadata.
long	getLongProperty(String property)	Similar to GetProperty(), but only works for a subset of properties whose return value is a numerical value.
long	getLongProperty(ColumnFamilyHandle columnFamilyHandle, String property)	Similar to GetProperty(), but only works for a subset of properties whose return value is a numerical value.
Map<String,String>	getMapProperty(String property)	Gets a property map.
Map<String,String>	getMapProperty(ColumnFamilyHandle columnFamilyHandle, String property)	Gets a property map.
String	getName()	Get DB name -- the exact same name that was provided as an argument to as path to open(Options, String).
MutableColumnFamilyOptions.MutableColumnFamilyOptionsBuilder	getOptions()	Default column family options
MutableColumnFamilyOptions.MutableColumnFamilyOptionsBuilder	getOptions(ColumnFamilyHandle columnFamilyHandle)	Get the options for the column family handle
PerfContext	getPerfContext()	Return perf context bound to this thread.
PerfLevel	getPerfLevel()	Return current performance level measurement settings.
Map<String,TableProperties>	getPropertiesOfAllTables()	Get the properties of all tables in the default column family.
Map<String,TableProperties>	getPropertiesOfAllTables(ColumnFamilyHandle columnFamilyHandle)	Get the properties of all tables.
Map<String,TableProperties>	getPropertiesOfTablesInRange(List<Range> ranges)	Get the properties of tables in range for the default column family.
Map<String,TableProperties>	getPropertiesOfTablesInRange(ColumnFamilyHandle columnFamilyHandle, List<Range> ranges)	Get the properties of tables in range.
String	getProperty(String property)	DB implementations can export properties about their state via this method.
String	getProperty(ColumnFamilyHandle columnFamilyHandle, String property)	DB implements can export properties about their state via this method on a per column family level.
Snapshot	getSnapshot()	Return a handle to the current DB state.
List<LogFile>	getSortedWalFiles()	Retrieve the sorted list of all wal files with earliest file first.
TransactionLogIterator	getUpdatesSince(long sequenceNumber)	Returns an iterator that is positioned at a write-batch containing seq_number.
void	ingestExternalFile(List<String> filePathList, IngestExternalFileOptions ingestExternalFileOptions)	ingestExternalFile will load a list of external SST files (1) into the DB We will try to find the lowest possible level that the file can fit in, and ingest the file into this level (2).
void	ingestExternalFile(ColumnFamilyHandle columnFamilyHandle, List<String> filePathList, IngestExternalFileOptions ingestExternalFileOptions)	ingestExternalFile will load a list of external SST files (1) into the DB We will try to find the lowest possible level that the file can fit in, and ingest the file into this level (2).
boolean	isClosed()
boolean	keyExists(byte[] key)	Check if a key exists in the database.
boolean	keyExists(byte[] key, int offset, int len)	Check if a key exists in the database.
boolean	keyExists(ByteBuffer key)	Check if a key exists in the database.
boolean	keyExists(ColumnFamilyHandle columnFamilyHandle, byte[] key)	Check if a key exists in the database.
boolean	keyExists(ColumnFamilyHandle columnFamilyHandle, byte[] key, int offset, int len)	Check if a key exists in the database.
boolean	keyExists(ColumnFamilyHandle columnFamilyHandle, ByteBuffer key)	Check if a key exists in the database.
boolean	keyExists(ColumnFamilyHandle columnFamilyHandle, ReadOptions readOptions, byte[] key)	Check if a key exists in the database.
boolean	keyExists(ColumnFamilyHandle columnFamilyHandle, ReadOptions readOptions, byte[] key, int offset, int len)	Check if a key exists in the database.
boolean	keyExists(ColumnFamilyHandle columnFamilyHandle, ReadOptions readOptions, ByteBuffer key)	Check if a key exists in the database.
boolean	keyExists(ReadOptions readOptions, byte[] key)	Check if a key exists in the database.
boolean	keyExists(ReadOptions readOptions, byte[] key, int offset, int len)	Check if a key exists in the database.
boolean	keyExists(ReadOptions readOptions, ByteBuffer key)	Check if a key exists in the database.
boolean	keyMayExist(byte[] key, int offset, int len, Holder<byte[]> valueHolder)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
boolean	keyMayExist(byte[] key, Holder<byte[]> valueHolder)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
boolean	keyMayExist(ByteBuffer key)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
KeyMayExist	keyMayExist(ByteBuffer key, ByteBuffer value)	If the key definitely does not exist in the database, then this method returns KeyMayExist.KeyMayExistEnum.kNotExist, otherwise if it can with best effort retreive the value, it returns KeyMayExist.KeyMayExistEnum.kExistsWithValue otherwise it returns KeyMayExist.KeyMayExistEnum.kExistsWithoutValue.
boolean	keyMayExist(ColumnFamilyHandle columnFamilyHandle, byte[] key, int offset, int len, Holder<byte[]> valueHolder)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
boolean	keyMayExist(ColumnFamilyHandle columnFamilyHandle, byte[] key, Holder<byte[]> valueHolder)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
boolean	keyMayExist(ColumnFamilyHandle columnFamilyHandle, ByteBuffer key)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
KeyMayExist	keyMayExist(ColumnFamilyHandle columnFamilyHandle, ByteBuffer key, ByteBuffer value)	If the key definitely does not exist in the database, then this method returns KeyMayExist.KeyMayExistEnum.kNotExist, otherwise if it can with best effort retreive the value, it returns KeyMayExist.KeyMayExistEnum.kExistsWithValue otherwise it returns KeyMayExist.KeyMayExistEnum.kExistsWithoutValue.
boolean	keyMayExist(ColumnFamilyHandle columnFamilyHandle, ReadOptions readOptions, byte[] key, int offset, int len, Holder<byte[]> valueHolder)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
boolean	keyMayExist(ColumnFamilyHandle columnFamilyHandle, ReadOptions readOptions, byte[] key, Holder<byte[]> valueHolder)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
boolean	keyMayExist(ColumnFamilyHandle columnFamilyHandle, ReadOptions readOptions, ByteBuffer key)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
KeyMayExist	keyMayExist(ColumnFamilyHandle columnFamilyHandle, ReadOptions readOptions, ByteBuffer key, ByteBuffer value)	If the key definitely does not exist in the database, then this method returns KeyMayExist.KeyMayExistEnum.kNotExist, otherwise if it can with best effort retreive the value, it returns KeyMayExist.KeyMayExistEnum.kExistsWithValue otherwise it returns KeyMayExist.KeyMayExistEnum.kExistsWithoutValue.
boolean	keyMayExist(ReadOptions readOptions, byte[] key, int offset, int len, Holder<byte[]> valueHolder)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
boolean	keyMayExist(ReadOptions readOptions, byte[] key, Holder<byte[]> valueHolder)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
boolean	keyMayExist(ReadOptions readOptions, ByteBuffer key)	If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist.
KeyMayExist	keyMayExist(ReadOptions readOptions, ByteBuffer key, ByteBuffer value)	If the key definitely does not exist in the database, then this method returns KeyMayExist.KeyMayExistEnum.kNotExist, otherwise if it can with best effort retreive the value, it returns KeyMayExist.KeyMayExistEnum.kExistsWithValue otherwise it returns KeyMayExist.KeyMayExistEnum.kExistsWithoutValue.
int	level0StopWriteTrigger()	Number of files in level-0 that would stop writes.
int	level0StopWriteTrigger(ColumnFamilyHandle columnFamilyHandle)	Number of files in level-0 that would stop writes.
static List<byte[]>	listColumnFamilies(Options options, String path)	Static method to determine all available column families for a rocksdb database identified by path
static void	loadLibrary()	Loads the necessary library files.
static void	loadLibrary(List<String> paths)	Tries to load the necessary library files from the given list of directories.
protected ColumnFamilyHandle	makeDefaultColumnFamilyHandle()	Create a handle for the default CF on open
int	maxMemCompactionLevel()	Maximum level to which a new compacted memtable is pushed if it does not create overlap.
int	maxMemCompactionLevel(ColumnFamilyHandle columnFamilyHandle)	Maximum level to which a new compacted memtable is pushed if it does not create overlap.
void	merge(byte[] key, byte[] value)	Add merge operand for key/value pair.
void	merge(byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Add merge operand for key/value pair.
void	merge(ColumnFamilyHandle columnFamilyHandle, byte[] key, byte[] value)	Add merge operand for key/value pair in a ColumnFamily.
void	merge(ColumnFamilyHandle columnFamilyHandle, byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Add merge operand for key/value pair in a ColumnFamily.
void	merge(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpts, byte[] key, byte[] value)	Add merge operand for key/value pair.
void	merge(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpts, byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Add merge operand for key/value pair.
void	merge(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpts, ByteBuffer key, ByteBuffer value)
void	merge(WriteOptions writeOpts, byte[] key, byte[] value)	Add merge operand for key/value pair.
void	merge(WriteOptions writeOpts, byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Add merge operand for key/value pair.
void	merge(WriteOptions writeOpts, ByteBuffer key, ByteBuffer value)
List<byte[]>	multiGetAsList(List<byte[]> keys)	Takes a list of keys, and returns a list of values for the given list of keys.
List<byte[]>	multiGetAsList(List<ColumnFamilyHandle> columnFamilyHandleList, List<byte[]> keys)	Returns a list of values for the given list of keys.
List<byte[]>	multiGetAsList(ReadOptions opt, List<byte[]> keys)	Returns a list of values for the given list of keys.
List<byte[]>	multiGetAsList(ReadOptions opt, List<ColumnFamilyHandle> columnFamilyHandleList, List<byte[]> keys)	Returns a list of values for the given list of keys.
List<ByteBufferGetStatus>	multiGetByteBuffers(List<ByteBuffer> keys, List<ByteBuffer> values)	Fetches a list of values for the given list of keys, all from the default column family.
List<ByteBufferGetStatus>	multiGetByteBuffers(List<ColumnFamilyHandle> columnFamilyHandleList, List<ByteBuffer> keys, List<ByteBuffer> values)	Fetches a list of values for the given list of keys.
List<ByteBufferGetStatus>	multiGetByteBuffers(ReadOptions readOptions, List<ByteBuffer> keys, List<ByteBuffer> values)	Fetches a list of values for the given list of keys, all from the default column family.
List<ByteBufferGetStatus>	multiGetByteBuffers(ReadOptions readOptions, List<ColumnFamilyHandle> columnFamilyHandleList, List<ByteBuffer> keys, List<ByteBuffer> values)	Fetches a list of values for the given list of keys.
RocksIterator	newIterator()	Return a heap-allocated iterator over the contents of the database.
RocksIterator	newIterator(ColumnFamilyHandle columnFamilyHandle)	Return a heap-allocated iterator over the contents of a ColumnFamily.
RocksIterator	newIterator(ColumnFamilyHandle columnFamilyHandle, ReadOptions readOptions)	Return a heap-allocated iterator over the contents of a ColumnFamily.
RocksIterator	newIterator(ReadOptions readOptions)	Return a heap-allocated iterator over the contents of the database.
List<RocksIterator>	newIterators(List<ColumnFamilyHandle> columnFamilyHandleList)	Returns iterators from a consistent database state across multiple column families.
List<RocksIterator>	newIterators(List<ColumnFamilyHandle> columnFamilyHandleList, ReadOptions readOptions)	Returns iterators from a consistent database state across multiple column families.
int	numberLevels()	Number of levels used for this DB.
int	numberLevels(ColumnFamilyHandle columnFamilyHandle)	Number of levels used for a column family in this DB.
static RocksDB	open(String path)	The factory constructor of RocksDB that opens a RocksDB instance given the path to the database using the default options w/ createIfMissing set to true.
static RocksDB	open(String path, List<ColumnFamilyDescriptor> columnFamilyDescriptors, List<ColumnFamilyHandle> columnFamilyHandles)	The factory constructor of RocksDB that opens a RocksDB instance given the path to the database using the specified options and db path and a list of column family names.
static RocksDB	open(DBOptions options, String path, List<ColumnFamilyDescriptor> columnFamilyDescriptors, List<ColumnFamilyHandle> columnFamilyHandles)	The factory constructor of RocksDB that opens a RocksDB instance given the path to the database using the specified options and db path and a list of column family names.
static RocksDB	open(Options options, String path)	The factory constructor of RocksDB that opens a RocksDB instance given the path to the database using the specified options and db path.
static RocksDB	openAsSecondary(DBOptions options, String path, String secondaryPath, List<ColumnFamilyDescriptor> columnFamilyDescriptors, List<ColumnFamilyHandle> columnFamilyHandles)	Open DB as secondary instance with column families.
static RocksDB	openAsSecondary(Options options, String path, String secondaryPath)	Open DB as secondary instance with only the default column family.
static RocksDB	openReadOnly(String path)	The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the default options.
static RocksDB	openReadOnly(String path, List<ColumnFamilyDescriptor> columnFamilyDescriptors, List<ColumnFamilyHandle> columnFamilyHandles)	The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the default options.
static RocksDB	openReadOnly(DBOptions options, String path, List<ColumnFamilyDescriptor> columnFamilyDescriptors, List<ColumnFamilyHandle> columnFamilyHandles)	The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the specified options and db path.
static RocksDB	openReadOnly(DBOptions options, String path, List<ColumnFamilyDescriptor> columnFamilyDescriptors, List<ColumnFamilyHandle> columnFamilyHandles, boolean errorIfWalFileExists)	The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the specified options and db path.
static RocksDB	openReadOnly(Options options, String path)	The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the specified options and db path.
static RocksDB	openReadOnly(Options options, String path, boolean errorIfWalFileExists)	The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the specified options and db path.
void	pauseBackgroundWork()	This function will wait until all currently running background processes finish.
void	promoteL0(int targetLevel)	Promote L0 for the default column family.
void	promoteL0(ColumnFamilyHandle columnFamilyHandle, int targetLevel)	Promote L0.
void	put(byte[] key, byte[] value)	Set the database entry for "key" to "value".
void	put(byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Set the database entry for "key" to "value".
void	put(ColumnFamilyHandle columnFamilyHandle, byte[] key, byte[] value)	Set the database entry for "key" to "value" in the specified column family.
void	put(ColumnFamilyHandle columnFamilyHandle, byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Set the database entry for "key" to "value" in the specified column family.
void	put(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpts, byte[] key, byte[] value)	Set the database entry for "key" to "value" for the specified column family.
void	put(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpts, byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Set the database entry for "key" to "value" for the specified column family.
void	put(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpts, ByteBuffer key, ByteBuffer value)	Set the database entry for "key" to "value" for the specified column family.
void	put(WriteOptions writeOpts, byte[] key, byte[] value)	Set the database entry for "key" to "value".
void	put(WriteOptions writeOpts, byte[] key, int offset, int len, byte[] value, int vOffset, int vLen)	Set the database entry for "key" to "value".
void	put(WriteOptions writeOpts, ByteBuffer key, ByteBuffer value)	Set the database entry for "key" to "value".
void	releaseSnapshot(Snapshot snapshot)	Release a previously acquired snapshot.
void	resetStats()	Reset internal stats for DB and all column families.
static RocksDB.Version	rocksdbVersion()
void	setDBOptions(MutableDBOptions mutableDBoptions)	Set the options for the column family handle.
void	setOptions(ColumnFamilyHandle columnFamilyHandle, MutableColumnFamilyOptions mutableColumnFamilyOptions)	Change the options for the column family handle.
void	setOptions(MutableColumnFamilyOptions mutableColumnFamilyOptions)	Change the options for the default column family handle.
void	setPerfLevel(PerfLevel level)	Set performance level for rocksdb performance measurement.
void	singleDelete(byte[] key)	Remove the database entry for key.
void	singleDelete(ColumnFamilyHandle columnFamilyHandle, byte[] key)	Remove the database entry for key.
void	singleDelete(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpt, byte[] key)	Remove the database entry for key.
void	singleDelete(WriteOptions writeOpt, byte[] key)	Remove the database entry for key.
void	startTrace(TraceOptions traceOptions, AbstractTraceWriter traceWriter)	Trace DB operations.
protected void	storeDefaultColumnFamilyHandle(ColumnFamilyHandle columnFamilyHandle)
protected void	storeOptionsInstance(DBOptionsInterface<?> options)
Range	suggestCompactRange()	Suggest the range to compact for the default column family.
Range	suggestCompactRange(ColumnFamilyHandle columnFamilyHandle)	Suggest the range to compact.
void	syncWal()	Sync the WAL.
void	tryCatchUpWithPrimary()	Make the secondary instance catch up with the primary by tailing and replaying the MANIFEST and WAL of the primary.
void	verifyChecksum()	Verify checksum
void	write(WriteOptions writeOpts, WriteBatch updates)	Apply the specified updates to the database.
void	write(WriteOptions writeOpts, WriteBatchWithIndex updates)	Apply the specified updates to the database.

Methods inherited from class org.rocksdb.RocksObject

disposeInternal, getNativeHandle

Methods inherited from class org.rocksdb.AbstractImmutableNativeReference

disOwnNativeHandle, isOwningHandle

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_COLUMN_FAMILY

public static final byte[] DEFAULT_COLUMN_FAMILY

NOT_FOUND

public static final int NOT_FOUND

See Also:

• Constant Field Values

options_

protected DBOptionsInterface<?> options_

Constructor Details

RocksDB

protected RocksDB(long nativeHandle)

Private constructor.

Parameters:

nativeHandle - The native handle of the C++ RocksDB object

Method Details

loadLibrary

public static void loadLibrary()

Loads the necessary library files. Calling this method twice will have no effect. By default the method extracts the shared library for loading at java.io.tmpdir, however, you can override this temporary location by setting the environment variable ROCKSDB_SHAREDLIB_DIR.

loadLibrary

public static void loadLibrary(List<String> paths)

Tries to load the necessary library files from the given list of directories.

Parameters:

paths - a list of strings where each describes a directory of a library.

rocksdbVersion

public static RocksDB.Version rocksdbVersion()

isClosed

public boolean isClosed()

open

public static RocksDB open(String path)
                    throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance given the path to the database using the default options w/ createIfMissing set to true.

Parameters:

path - the path to the rocksdb.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

See Also:

• Options.setCreateIfMissing(boolean)

open

public static RocksDB open(String path,
 List<ColumnFamilyDescriptor> columnFamilyDescriptors,
 List<ColumnFamilyHandle> columnFamilyHandles)
                    throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance given the path to the database using the specified options and db path and a list of column family names.

If opened in read write mode every existing column family name must be passed within the list to this method.

If opened in read-only mode only a subset of existing column families must be passed to this method.

Options instance *should* not be disposed before all DBs using this options instance have been closed. If user doesn't call options dispose explicitly, then this options instance will be GC'd automatically

ColumnFamily handles are disposed when the RocksDB instance is disposed.

Parameters:

path - the path to the rocksdb.

columnFamilyDescriptors - list of column family descriptors

columnFamilyHandles - will be filled with ColumnFamilyHandle instances on open.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

See Also:

• DBOptions.setCreateIfMissing(boolean)

open

public static RocksDB open(Options options,
 String path)
                    throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance given the path to the database using the specified options and db path.

Options instance *should* not be disposed before all DBs using this options instance have been closed. If user doesn't call options dispose explicitly, then this options instance will be GC'd automatically.

Options instance can be re-used to open multiple DBs if DB statistics is not used. If DB statistics are required, then its recommended to open DB with new Options instance as underlying native statistics instance does not use any locks to prevent concurrent updates.

Parameters:

options - Options instance.

path - the path to the rocksdb.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

See Also:

• Options.setCreateIfMissing(boolean)

open

public static RocksDB open(DBOptions options,
 String path,
 List<ColumnFamilyDescriptor> columnFamilyDescriptors,
 List<ColumnFamilyHandle> columnFamilyHandles)
                    throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance given the path to the database using the specified options and db path and a list of column family names.

If opened in read write mode every existing column family name must be passed within the list to this method.

If opened in read-only mode only a subset of existing column families must be passed to this method.

Options instance *should* not be disposed before all DBs using this options instance have been closed. If user doesn't call options dispose explicitly, then this options instance will be GC'd automatically.

Options instance can be re-used to open multiple DBs if DB statistics is not used. If DB statistics are required, then its recommended to open DB with new Options instance as underlying native statistics instance does not use any locks to prevent concurrent updates.

ColumnFamily handles are disposed when the RocksDB instance is disposed.

Parameters:

options - DBOptions instance.

path - the path to the rocksdb.

columnFamilyDescriptors - list of column family descriptors

columnFamilyHandles - will be filled with ColumnFamilyHandle instances on open.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

See Also:

• DBOptions.setCreateIfMissing(boolean)

openReadOnly

public static RocksDB openReadOnly(String path)
                            throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the default options.

Parameters:

path - the path to the RocksDB.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

openReadOnly

public static RocksDB openReadOnly(Options options,
 String path)
                            throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the specified options and db path.

Options instance *should* not be disposed before all DBs using this options instance have been closed. If user doesn't call options dispose explicitly, then this options instance will be GC'd automatically.

Parameters:

options - Options instance.

path - the path to the RocksDB.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

openReadOnly

public static RocksDB openReadOnly(Options options,
 String path,
 boolean errorIfWalFileExists)
                            throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the specified options and db path.

Options instance *should* not be disposed before all DBs using this options instance have been closed. If user doesn't call options dispose explicitly, then this options instance will be GC'd automatically.

Parameters:

options - Options instance.

path - the path to the RocksDB.

errorIfWalFileExists - true to raise an error when opening the db if a Write Ahead Log file exists, false otherwise.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

openReadOnly

public static RocksDB openReadOnly(String path,
 List<ColumnFamilyDescriptor> columnFamilyDescriptors,
 List<ColumnFamilyHandle> columnFamilyHandles)
                            throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the default options.

Parameters:

path - the path to the RocksDB.

columnFamilyDescriptors - list of column family descriptors

columnFamilyHandles - will be filled with ColumnFamilyHandle instances on open.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

openReadOnly

public static RocksDB openReadOnly(DBOptions options,
 String path,
 List<ColumnFamilyDescriptor> columnFamilyDescriptors,
 List<ColumnFamilyHandle> columnFamilyHandles)
                            throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the specified options and db path.

This open method allows to open RocksDB using a subset of available column families

Options instance *should* not be disposed before all DBs using this options instance have been closed. If user doesn't call options dispose explicitly,then this options instance will be GC'd automatically.

Parameters:

options - DBOptions instance.

path - the path to the RocksDB.

columnFamilyDescriptors - list of column family descriptors

columnFamilyHandles - will be filled with ColumnFamilyHandle instances on open.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

openReadOnly

public static RocksDB openReadOnly(DBOptions options,
 String path,
 List<ColumnFamilyDescriptor> columnFamilyDescriptors,
 List<ColumnFamilyHandle> columnFamilyHandles,
 boolean errorIfWalFileExists)
                            throws RocksDBException

The factory constructor of RocksDB that opens a RocksDB instance in Read-Only mode given the path to the database using the specified options and db path.

This open method allows to open RocksDB using a subset of available column families

Options instance *should* not be disposed before all DBs using this options instance have been closed. If user doesn't call options dispose explicitly,then this options instance will be GC'd automatically.

Parameters:

options - DBOptions instance.

path - the path to the RocksDB.

columnFamilyDescriptors - list of column family descriptors

columnFamilyHandles - will be filled with ColumnFamilyHandle instances on open.

errorIfWalFileExists - true to raise an error when opening the db if a Write Ahead Log file exists, false otherwise.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

openAsSecondary

public static RocksDB openAsSecondary(Options options,
 String path,
 String secondaryPath)
                               throws RocksDBException

Open DB as secondary instance with only the default column family.

The secondary instance can dynamically tail the MANIFEST of a primary that must have already been created. User can call tryCatchUpWithPrimary() to make the secondary instance catch up with primary (WAL tailing is NOT supported now) whenever the user feels necessary. Column families created by the primary after the secondary instance starts are currently ignored by the secondary instance. Column families opened by secondary and dropped by the primary will be dropped by secondary as well. However the user of the secondary instance can still access the data of such dropped column family as long as they do not destroy the corresponding column family handle. WAL tailing is not supported at present, but will arrive soon.

Parameters:

options - the options to open the secondary instance.

path - the path to the primary RocksDB instance.

secondaryPath - points to a directory where the secondary instance stores its info log

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

openAsSecondary

public static RocksDB openAsSecondary(DBOptions options,
 String path,
 String secondaryPath,
 List<ColumnFamilyDescriptor> columnFamilyDescriptors,
 List<ColumnFamilyHandle> columnFamilyHandles)
                               throws RocksDBException

Open DB as secondary instance with column families. You can open a subset of column families in secondary mode.

The secondary instance can dynamically tail the MANIFEST of a primary that must have already been created. User can call tryCatchUpWithPrimary() to make the secondary instance catch up with primary (WAL tailing is NOT supported now) whenever the user feels necessary. Column families created by the primary after the secondary instance starts are currently ignored by the secondary instance. Column families opened by secondary and dropped by the primary will be dropped by secondary as well. However the user of the secondary instance can still access the data of such dropped column family as long as they do not destroy the corresponding column family handle. WAL tailing is not supported at present, but will arrive soon.

Parameters:

options - the options to open the secondary instance.

path - the path to the primary RocksDB instance.

secondaryPath - points to a directory where the secondary instance stores its info log.

columnFamilyDescriptors - list of column family descriptors

columnFamilyHandles - will be filled with ColumnFamilyHandle instances on open.

Returns:

a RocksDB instance on success, null if the specified RocksDB can not be opened.

Throws:

RocksDBException - thrown if error happens in underlying native library.

closeE

public void closeE()
            throws RocksDBException

This is similar to close() except that it throws an exception if any error occurs.

This will not fsync the WAL files. If syncing is required, the caller must first call syncWal() or write(WriteOptions, WriteBatch) using an empty write batch with WriteOptions.setSync(boolean) set to true.

See also close().

Throws:

RocksDBException - if an error occurs whilst closing.

close

public void close()

This is similar to closeE() except that it silently ignores any errors.

This will not fsync the WAL files. If syncing is required, the caller must first call syncWal() or write(WriteOptions, WriteBatch) using an empty write batch with WriteOptions.setSync(boolean) set to true.

See also close().

Specified by:

close in interface AutoCloseable

Overrides:

close in class AbstractImmutableNativeReference

listColumnFamilies

public static List<byte[]> listColumnFamilies(Options options,
 String path)
                                       throws RocksDBException

Static method to determine all available column families for a rocksdb database identified by path

Parameters:

options - Options for opening the database

path - Absolute path to rocksdb database

Returns:

List<byte[]> List containing the column family names

Throws:

RocksDBException - thrown if error happens in underlying native library.

createColumnFamily

public ColumnFamilyHandle createColumnFamily(ColumnFamilyDescriptor columnFamilyDescriptor)
                                      throws RocksDBException

Creates a new column family with the name columnFamilyName and allocates a ColumnFamilyHandle within an internal structure. The ColumnFamilyHandle is automatically disposed with DB disposal.

Parameters:

columnFamilyDescriptor - column family to be created.

Returns:

ColumnFamilyHandle instance.

Throws:

RocksDBException - thrown if error happens in underlying native library.

createColumnFamilies

public List<ColumnFamilyHandle> createColumnFamilies(ColumnFamilyOptions columnFamilyOptions,
 List<byte[]> columnFamilyNames)
                                              throws RocksDBException

Bulk create column families with the same column family options.

Parameters:

columnFamilyOptions - the options for the column families.

columnFamilyNames - the names of the column families.

Returns:

the handles to the newly created column families.

Throws:

RocksDBException - if an error occurs whilst creating the column families

createColumnFamilies

public List<ColumnFamilyHandle> createColumnFamilies(List<ColumnFamilyDescriptor> columnFamilyDescriptors)
                                              throws RocksDBException

Bulk create column families with the same column family options.

Parameters:

columnFamilyDescriptors - the descriptions of the column families.

Returns:

the handles to the newly created column families.

Throws:

RocksDBException - if an error occurs whilst creating the column families

createColumnFamilyWithImport

public ColumnFamilyHandle createColumnFamilyWithImport(ColumnFamilyDescriptor columnFamilyDescriptor,
 ImportColumnFamilyOptions importColumnFamilyOptions,
 ExportImportFilesMetaData metadata)
                                                throws RocksDBException

Creates a new column family with the name columnFamilyName and import external SST files specified in `metadata` allocates a ColumnFamilyHandle within an internal structure. The ColumnFamilyHandle is automatically disposed with DB disposal.

Parameters:

columnFamilyDescriptor - column family to be created.

Returns:

ColumnFamilyHandle instance.

Throws:

RocksDBException - thrown if error happens in underlying native library.

createColumnFamilyWithImport

public ColumnFamilyHandle createColumnFamilyWithImport(ColumnFamilyDescriptor columnFamilyDescriptor,
 ImportColumnFamilyOptions importColumnFamilyOptions,
 List<ExportImportFilesMetaData> metadatas)
                                                throws RocksDBException

Throws:

RocksDBException

dropColumnFamily

public void dropColumnFamily(ColumnFamilyHandle columnFamilyHandle)
                      throws RocksDBException

Drops the column family specified by columnFamilyHandle. This call only records a drop record in the manifest and prevents the column family from flushing and compacting.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

Throws:

RocksDBException - thrown if error happens in underlying native library.

dropColumnFamilies

public void dropColumnFamilies(List<ColumnFamilyHandle> columnFamilies)
                        throws RocksDBException

Throws:

RocksDBException

destroyColumnFamilyHandle

public void destroyColumnFamilyHandle(ColumnFamilyHandle columnFamilyHandle)

Deletes native column family handle of given ColumnFamilyHandle Java object and removes reference from ownedColumnFamilyHandles.

Parameters:

columnFamilyHandle - column family handle object.

put

public void put(byte[] key,
 byte[] value)
         throws RocksDBException

Set the database entry for "key" to "value".

Parameters:

key - the specified key to be inserted.

value - the value associated with the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

put

public void put(byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
         throws RocksDBException

Set the database entry for "key" to "value".

Parameters:

key - The specified key to be inserted

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

value - the value associated with the specified key

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be non-negative and no larger than ("value".length - offset)

Throws:

RocksDBException - thrown if errors happens in underlying native library.

IndexOutOfBoundsException - if an offset or length is out of bounds

put

public void put(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 byte[] value)
         throws RocksDBException

Set the database entry for "key" to "value" in the specified column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - the specified key to be inserted.

value - the value associated with the specified key.

throws IllegalArgumentException if column family is not present

Throws:

RocksDBException - thrown if error happens in underlying native library.

put

public void put(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
         throws RocksDBException

Set the database entry for "key" to "value" in the specified column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - The specified key to be inserted

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

value - the value associated with the specified key

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be non-negative and no larger than ("value".length - offset)

Throws:

RocksDBException - thrown if errors happens in underlying native library.

IndexOutOfBoundsException - if an offset or length is out of bounds

put

public void put(WriteOptions writeOpts,
 byte[] key,
 byte[] value)
         throws RocksDBException

Set the database entry for "key" to "value".

Parameters:

writeOpts - WriteOptions instance.

key - the specified key to be inserted.

value - the value associated with the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

put

public void put(WriteOptions writeOpts,
 byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
         throws RocksDBException

Set the database entry for "key" to "value".

Parameters:

writeOpts - WriteOptions instance.

key - The specified key to be inserted

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

value - the value associated with the specified key

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be non-negative and no larger than ("value".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

IndexOutOfBoundsException - if an offset or length is out of bounds

put

public void put(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpts,
 byte[] key,
 byte[] value)
         throws RocksDBException

Set the database entry for "key" to "value" for the specified column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

writeOpts - WriteOptions instance.

key - the specified key to be inserted.

value - the value associated with the specified key.

throws IllegalArgumentException if column family is not present

Throws:

RocksDBException - thrown if error happens in underlying native library.

See Also:

• IllegalArgumentException

put

public void put(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpts,
 ByteBuffer key,
 ByteBuffer value)
         throws RocksDBException

Set the database entry for "key" to "value" for the specified column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

writeOpts - WriteOptions instance.

key - the specified key to be inserted. Position and limit is used. Supports direct buffer only.

value - the value associated with the specified key. Position and limit is used. Supports direct buffer only.

throws IllegalArgumentException if column family is not present

Throws:

RocksDBException - thrown if error happens in underlying native library.

See Also:

• IllegalArgumentException

put

public void put(WriteOptions writeOpts,
 ByteBuffer key,
 ByteBuffer value)
         throws RocksDBException

Set the database entry for "key" to "value".

Parameters:

writeOpts - WriteOptions instance.

key - the specified key to be inserted. Position and limit is used. Supports direct buffer only.

value - the value associated with the specified key. Position and limit is used. Supports direct buffer only.

throws IllegalArgumentException if column family is not present

Throws:

RocksDBException - thrown if error happens in underlying native library.

See Also:

• IllegalArgumentException

put

public void put(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpts,
 byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
         throws RocksDBException

Set the database entry for "key" to "value" for the specified column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

writeOpts - WriteOptions instance.

key - The specified key to be inserted

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

value - the value associated with the specified key

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be non-negative and no larger than ("value".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

IndexOutOfBoundsException - if an offset or length is out of bounds

delete

public void delete(byte[] key)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

key - Key to delete within database

Throws:

RocksDBException - thrown if error happens in underlying native library.

delete

public void delete(byte[] key,
 int offset,
 int len)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

key - Key to delete within database

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

delete

public void delete(ColumnFamilyHandle columnFamilyHandle,
 byte[] key)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - Key to delete within database

Throws:

RocksDBException - thrown if error happens in underlying native library.

delete

public void delete(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 int offset,
 int len)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - Key to delete within database

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("value".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

delete

public void delete(WriteOptions writeOpt,
 byte[] key)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

writeOpt - WriteOptions to be used with delete operation

key - Key to delete within database

Throws:

RocksDBException - thrown if error happens in underlying native library.

delete

public void delete(WriteOptions writeOpt,
 byte[] key,
 int offset,
 int len)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

writeOpt - WriteOptions to be used with delete operation

key - Key to delete within database

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

delete

public void delete(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpt,
 byte[] key)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

writeOpt - WriteOptions to be used with delete operation

key - Key to delete within database

Throws:

RocksDBException - thrown if error happens in underlying native library.

delete

public void delete(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpt,
 byte[] key,
 int offset,
 int len)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

writeOpt - WriteOptions to be used with delete operation

key - Key to delete within database

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public int get(ReadOptions opt,
 ByteBuffer key,
 ByteBuffer value)
        throws RocksDBException

Get the value associated with the specified key within column family.

Parameters:

opt - ReadOptions instance.

key - the key to retrieve the value. It is using position and limit. Supports direct buffer only.

value - the out-value to receive the retrieved value. It is using position and limit. Limit is set according to value size. Supports direct buffer only.

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public int get(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions opt,
 ByteBuffer key,
 ByteBuffer value)
        throws RocksDBException

Get the value associated with the specified key within column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

opt - ReadOptions instance.

key - the key to retrieve the value. It is using position and limit. Supports direct buffer only.

value - the out-value to receive the retrieved value. It is using position and limit. Limit is set according to value size. Supports direct buffer only.

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

singleDelete

@Experimental("Performance optimization for a very specific workload")
public void singleDelete(byte[] key)
                  throws RocksDBException

Remove the database entry for key. Requires that the key exists and was not overwritten. It is not an error if the key did not exist in the database.

If a key is overwritten (by calling put(byte[], byte[]) multiple times), then the result of calling SingleDelete() on this key is undefined. SingleDelete() only behaves correctly if there has been only one Put() for this key since the previous call to SingleDelete() for this key.

This feature is currently an experimental performance optimization for a very specific workload. It is up to the caller to ensure that SingleDelete is only used for a key that is not deleted using Delete() or written using Merge(). Mixing SingleDelete operations with Deletes and Merges can result in undefined behavior.

Parameters:

key - Key to delete within database

Throws:

RocksDBException - thrown if error happens in underlying native library.

singleDelete

@Experimental("Performance optimization for a very specific workload")
public void singleDelete(ColumnFamilyHandle columnFamilyHandle,
 byte[] key)
                  throws RocksDBException

Remove the database entry for key. Requires that the key exists and was not overwritten. It is not an error if the key did not exist in the database.

If a key is overwritten (by calling put(byte[], byte[]) multiple times), then the result of calling SingleDelete() on this key is undefined. SingleDelete() only behaves correctly if there has been only one Put() for this key since the previous call to SingleDelete() for this key.

This feature is currently an experimental performance optimization for a very specific workload. It is up to the caller to ensure that SingleDelete is only used for a key that is not deleted using Delete() or written using Merge(). Mixing SingleDelete operations with Deletes and Merges can result in undefined behavior.

Parameters:

columnFamilyHandle - The column family to delete the key from

key - Key to delete within database

Throws:

RocksDBException - thrown if error happens in underlying native library.

singleDelete

@Experimental("Performance optimization for a very specific workload")
public void singleDelete(WriteOptions writeOpt,
 byte[] key)
                  throws RocksDBException

Remove the database entry for key. Requires that the key exists and was not overwritten. It is not an error if the key did not exist in the database.

If a key is overwritten (by calling put(byte[], byte[]) multiple times), then the result of calling SingleDelete() on this key is undefined. SingleDelete() only behaves correctly if there has been only one Put() for this key since the previous call to SingleDelete() for this key.

This feature is currently an experimental performance optimization for a very specific workload. It is up to the caller to ensure that SingleDelete is only used for a key that is not deleted using Delete() or written using Merge(). Mixing SingleDelete operations with Deletes and Merges can result in undefined behavior.

Note: consider setting WriteOptions.setSync(boolean) true.

Parameters:

writeOpt - Write options for the delete

key - Key to delete within database

Throws:

RocksDBException - thrown if error happens in underlying native library.

singleDelete

@Experimental("Performance optimization for a very specific workload")
public void singleDelete(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpt,
 byte[] key)
                  throws RocksDBException

Remove the database entry for key. Requires that the key exists and was not overwritten. It is not an error if the key did not exist in the database.

If a key is overwritten (by calling put(byte[], byte[]) multiple times), then the result of calling SingleDelete() on this key is undefined. SingleDelete() only behaves correctly if there has been only one Put() for this key since the previous call to SingleDelete() for this key.

This feature is currently an experimental performance optimization for a very specific workload. It is up to the caller to ensure that SingleDelete is only used for a key that is not deleted using Delete() or written using Merge(). Mixing SingleDelete operations with Deletes and Merges can result in undefined behavior.

Note: consider setting WriteOptions.setSync(boolean) true.

Parameters:

columnFamilyHandle - The column family to delete the key from

writeOpt - Write options for the delete

key - Key to delete within database

Throws:

RocksDBException - thrown if error happens in underlying native library.

deleteRange

public void deleteRange(byte[] beginKey,
 byte[] endKey)
                 throws RocksDBException

Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey". a non-OK status on error. It is not an error if no keys exist in the range ["beginKey", "endKey").

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

beginKey - First key to delete within database (inclusive)

endKey - Last key to delete within database (exclusive)

Throws:

RocksDBException - thrown if error happens in underlying native library.

deleteRange

public void deleteRange(ColumnFamilyHandle columnFamilyHandle,
 byte[] beginKey,
 byte[] endKey)
                 throws RocksDBException

Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey". a non-OK status on error. It is not an error if no keys exist in the range ["beginKey", "endKey").

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

beginKey - First key to delete within database (inclusive)

endKey - Last key to delete within database (exclusive)

Throws:

RocksDBException - thrown if error happens in underlying native library.

deleteRange

public void deleteRange(WriteOptions writeOpt,
 byte[] beginKey,
 byte[] endKey)
                 throws RocksDBException

Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey". a non-OK status on error. It is not an error if no keys exist in the range ["beginKey", "endKey").

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

writeOpt - WriteOptions to be used with delete operation

beginKey - First key to delete within database (inclusive)

endKey - Last key to delete within database (exclusive)

Throws:

RocksDBException - thrown if error happens in underlying native library.

deleteRange

public void deleteRange(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpt,
 byte[] beginKey,
 byte[] endKey)
                 throws RocksDBException

Removes the database entries in the range ["beginKey", "endKey"), i.e., including "beginKey" and excluding "endKey". a non-OK status on error. It is not an error if no keys exist in the range ["beginKey", "endKey").

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

writeOpt - WriteOptions to be used with delete operation

beginKey - First key to delete within database (included)

endKey - Last key to delete within database (excluded)

Throws:

RocksDBException - thrown if error happens in underlying native library.

merge

public void merge(byte[] key,
 byte[] value)
           throws RocksDBException

Add merge operand for key/value pair.

Parameters:

key - the specified key to be merged.

value - the value to be merged with the current value for the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

merge

public void merge(byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
           throws RocksDBException

Add merge operand for key/value pair.

Parameters:

key - the specified key to be merged.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

value - the value to be merged with the current value for the specified key.

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be non-negative and must be non-negative and no larger than ("value".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

IndexOutOfBoundsException - if an offset or length is out of bounds

merge

public void merge(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 byte[] value)
           throws RocksDBException

Add merge operand for key/value pair in a ColumnFamily.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - the specified key to be merged.

value - the value to be merged with the current value for the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

merge

public void merge(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
           throws RocksDBException

Add merge operand for key/value pair in a ColumnFamily.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - the specified key to be merged.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

value - the value to be merged with the current value for the specified key.

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be must be non-negative and no larger than ("value".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

IndexOutOfBoundsException - if an offset or length is out of bounds

merge

public void merge(WriteOptions writeOpts,
 byte[] key,
 byte[] value)
           throws RocksDBException

Add merge operand for key/value pair.

Parameters:

writeOpts - WriteOptions for this write.

key - the specified key to be merged.

value - the value to be merged with the current value for the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

merge

public void merge(WriteOptions writeOpts,
 byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
           throws RocksDBException

Add merge operand for key/value pair.

Parameters:

writeOpts - WriteOptions for this write.

key - the specified key to be merged.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("value".length - offset)

value - the value to be merged with the current value for the specified key.

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be non-negative and no larger than ("value".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

IndexOutOfBoundsException - if an offset or length is out of bounds

merge

public void merge(WriteOptions writeOpts,
 ByteBuffer key,
 ByteBuffer value)
           throws RocksDBException

Throws:

RocksDBException

merge

public void merge(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpts,
 ByteBuffer key,
 ByteBuffer value)
           throws RocksDBException

Throws:

RocksDBException

delete

public void delete(WriteOptions writeOpt,
 ByteBuffer key)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

writeOpt - WriteOptions to be used with delete operation

key - Key to delete within database. It is using position and limit. Supports direct buffer only.

Throws:

RocksDBException - thrown if error happens in underlying native library.

delete

public void delete(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpt,
 ByteBuffer key)
            throws RocksDBException

Delete the database entry (if any) for "key". Returns OK on success, and a non-OK status on error. It is not an error if "key" did not exist in the database.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

writeOpt - WriteOptions to be used with delete operation

key - Key to delete within database. It is using position and limit. Supports direct buffer only.

Throws:

RocksDBException - thrown if error happens in underlying native library.

merge

public void merge(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpts,
 byte[] key,
 byte[] value)
           throws RocksDBException

Add merge operand for key/value pair.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

writeOpts - WriteOptions for this write.

key - the specified key to be merged.

value - the value to be merged with the current value for the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

merge

public void merge(ColumnFamilyHandle columnFamilyHandle,
 WriteOptions writeOpts,
 byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
           throws RocksDBException

Add merge operand for key/value pair.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

writeOpts - WriteOptions for this write.

key - the specified key to be merged.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

value - the value to be merged with the current value for the specified key.

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be non-negative and no larger than ("value".length - offset)

Throws:

RocksDBException - thrown if error happens in underlying native library.

IndexOutOfBoundsException - if an offset or length is out of bounds

write

public void write(WriteOptions writeOpts,
 WriteBatch updates)
           throws RocksDBException

Apply the specified updates to the database.

Parameters:

writeOpts - WriteOptions instance

updates - WriteBatch instance

Throws:

RocksDBException - thrown if error happens in underlying native library.

write

public void write(WriteOptions writeOpts,
 WriteBatchWithIndex updates)
           throws RocksDBException

Apply the specified updates to the database.

Parameters:

writeOpts - WriteOptions instance

updates - WriteBatchWithIndex instance

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public int get(byte[] key,
 byte[] value)
        throws RocksDBException

Get the value associated with the specified key within column family*

Parameters:

key - the key to retrieve the value.

value - the out-value to receive the retrieved value.

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public int get(byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
        throws RocksDBException

Get the value associated with the specified key within column family*

Parameters:

key - the key to retrieve the value.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

value - the out-value to receive the retrieved value.

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "value".length

vLen - the length of the "value" array to be used, must be non-negative and and no larger than ("value".length - offset)

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public int get(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 byte[] value)
        throws RocksDBException,
IllegalArgumentException

Get the value associated with the specified key within column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - the key to retrieve the value.

value - the out-value to receive the retrieved value.

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

IllegalArgumentException

get

public int get(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
        throws RocksDBException,
IllegalArgumentException

Get the value associated with the specified key within column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - the key to retrieve the value.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative an no larger than ("key".length - offset)

value - the out-value to receive the retrieved value.

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be non-negative and no larger than ("value".length - offset)

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

IllegalArgumentException

get

public int get(ReadOptions opt,
 byte[] key,
 byte[] value)
        throws RocksDBException

Get the value associated with the specified key.

Parameters:

opt - ReadOptions instance.

key - the key to retrieve the value.

value - the out-value to receive the retrieved value.

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public int get(ReadOptions opt,
 byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
        throws RocksDBException

Get the value associated with the specified key.

Parameters:

opt - ReadOptions instance.

key - the key to retrieve the value.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

value - the out-value to receive the retrieved value.

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, must be non-negative and no larger than ("value".length - offset)

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public int get(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions opt,
 byte[] key,
 byte[] value)
        throws RocksDBException

Get the value associated with the specified key within column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

opt - ReadOptions instance.

key - the key to retrieve the value.

value - the out-value to receive the retrieved value.

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public int get(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions opt,
 byte[] key,
 int offset,
 int len,
 byte[] value,
 int vOffset,
 int vLen)
        throws RocksDBException

Get the value associated with the specified key within column family.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

opt - ReadOptions instance.

key - the key to retrieve the value.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and and no larger than ("key".length - offset)

value - the out-value to receive the retrieved value.

vOffset - the offset of the "value" array to be used, must be non-negative and no longer than "key".length

vLen - the length of the "value" array to be used, and must be non-negative and no larger than ("value".length - offset)

Returns:

The size of the actual value that matches the specified key in byte. If the return value is greater than the length of value, then it indicates that the size of the input buffer value is insufficient and partial result will be returned. RocksDB.NOT_FOUND will be returned if the value not found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public byte[] get(byte[] key)
           throws RocksDBException

The simplified version of get which returns a new byte array storing the value associated with the specified input key if any. null will be returned if the specified key is not found.

Parameters:

key - the key retrieve the value.

Returns:

a byte array storing the value associated with the input key if any. null if it does not find the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public byte[] get(byte[] key,
 int offset,
 int len)
           throws RocksDBException

The simplified version of get which returns a new byte array storing the value associated with the specified input key if any. null will be returned if the specified key is not found.

Parameters:

key - the key retrieve the value.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

Returns:

a byte array storing the value associated with the input key if any. null if it does not find the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public byte[] get(ColumnFamilyHandle columnFamilyHandle,
 byte[] key)
           throws RocksDBException

The simplified version of get which returns a new byte array storing the value associated with the specified input key if any. null will be returned if the specified key is not found.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - the key retrieve the value.

Returns:

a byte array storing the value associated with the input key if any. null if it does not find the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public byte[] get(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 int offset,
 int len)
           throws RocksDBException

The simplified version of get which returns a new byte array storing the value associated with the specified input key if any. null will be returned if the specified key is not found.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - the key retrieve the value.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

Returns:

a byte array storing the value associated with the input key if any. null if it does not find the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public byte[] get(ReadOptions opt,
 byte[] key)
           throws RocksDBException

The simplified version of get which returns a new byte array storing the value associated with the specified input key if any. null will be returned if the specified key is not found.

Parameters:

opt - Read options.

key - the key retrieve the value.

Returns:

a byte array storing the value associated with the input key if any. null if it does not find the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public byte[] get(ReadOptions opt,
 byte[] key,
 int offset,
 int len)
           throws RocksDBException

The simplified version of get which returns a new byte array storing the value associated with the specified input key if any. null will be returned if the specified key is not found.

Parameters:

opt - Read options.

key - the key retrieve the value.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

Returns:

a byte array storing the value associated with the input key if any. null if it does not find the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public byte[] get(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions opt,
 byte[] key)
           throws RocksDBException

The simplified version of get which returns a new byte array storing the value associated with the specified input key if any. null will be returned if the specified key is not found.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

opt - Read options.

key - the key retrieve the value.

Returns:

a byte array storing the value associated with the input key if any. null if it does not find the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

get

public byte[] get(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions opt,
 byte[] key,
 int offset,
 int len)
           throws RocksDBException

The simplified version of get which returns a new byte array storing the value associated with the specified input key if any. null will be returned if the specified key is not found.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

opt - Read options.

key - the key retrieve the value.

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than ("key".length - offset)

Returns:

a byte array storing the value associated with the input key if any. null if it does not find the specified key.

Throws:

RocksDBException - thrown if error happens in underlying native library.

multiGetAsList

public List<byte[]> multiGetAsList(List<byte[]> keys)
                            throws RocksDBException

Takes a list of keys, and returns a list of values for the given list of keys. List will contain null for keys which could not be found.

Parameters:

keys - List of keys for which values need to be retrieved.

Returns:

List of values for the given list of keys. List will contain null for keys which could not be found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

multiGetAsList

public List<byte[]> multiGetAsList(List<ColumnFamilyHandle> columnFamilyHandleList,
 List<byte[]> keys)
                            throws RocksDBException,
IllegalArgumentException

Returns a list of values for the given list of keys. List will contain null for keys which could not be found.

Note: Every key needs to have a related column family name in columnFamilyHandleList.

Parameters:

columnFamilyHandleList - List containing ColumnFamilyHandle instances.

keys - List of keys for which values need to be retrieved.

Returns:

List of values for the given list of keys. List will contain null for keys which could not be found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

IllegalArgumentException - thrown if the size of passed keys is not equal to the amount of passed column family handles.

multiGetAsList

public List<byte[]> multiGetAsList(ReadOptions opt,
 List<byte[]> keys)
                            throws RocksDBException

Returns a list of values for the given list of keys. List will contain null for keys which could not be found.

Parameters:

opt - Read options.

keys - of keys for which values need to be retrieved.

Returns:

List of values for the given list of keys. List will contain null for keys which could not be found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

multiGetAsList

public List<byte[]> multiGetAsList(ReadOptions opt,
 List<ColumnFamilyHandle> columnFamilyHandleList,
 List<byte[]> keys)
                            throws RocksDBException

Returns a list of values for the given list of keys. List will contain null for keys which could not be found.

Note: Every key needs to have a related column family name in columnFamilyHandleList.

Parameters:

opt - Read options.

columnFamilyHandleList - List containing ColumnFamilyHandle instances.

keys - of keys for which values need to be retrieved.

Returns:

List of values for the given list of keys. List will contain null for keys which could not be found.

Throws:

RocksDBException - thrown if error happens in underlying native library.

IllegalArgumentException - thrown if the size of passed keys is not equal to the amount of passed column family handles.

multiGetByteBuffers

public List<ByteBufferGetStatus> multiGetByteBuffers(List<ByteBuffer> keys,
 List<ByteBuffer> values)
                                              throws RocksDBException

Fetches a list of values for the given list of keys, all from the default column family.

Parameters:

keys - list of keys for which values need to be retrieved.

values - list of buffers to return retrieved values in

Returns:

list of number of bytes in DB for each requested key this can be more than the size of the corresponding buffer; then the buffer will be filled with the appropriate truncation of the database value.

Throws:

RocksDBException - if error happens in underlying native library.

IllegalArgumentException - thrown if the number of passed keys and passed values do not match.

multiGetByteBuffers

public List<ByteBufferGetStatus> multiGetByteBuffers(ReadOptions readOptions,
 List<ByteBuffer> keys,
 List<ByteBuffer> values)
                                              throws RocksDBException

Fetches a list of values for the given list of keys, all from the default column family.

Parameters:

readOptions - Read options

keys - list of keys for which values need to be retrieved.

values - list of buffers to return retrieved values in

Returns:

the list of values for the given list of keys

Throws:

RocksDBException - if error happens in underlying native library.

IllegalArgumentException - thrown if the number of passed keys and passed values do not match.

multiGetByteBuffers

public List<ByteBufferGetStatus> multiGetByteBuffers(List<ColumnFamilyHandle> columnFamilyHandleList,
 List<ByteBuffer> keys,
 List<ByteBuffer> values)
                                              throws RocksDBException

Fetches a list of values for the given list of keys.

Note: Every key needs to have a related column family name in columnFamilyHandleList.

Parameters:

columnFamilyHandleList - List containing ColumnFamilyHandle instances.

keys - list of keys for which values need to be retrieved.

values - list of buffers to return retrieved values in

Returns:

the list of values for the given list of keys

Throws:

RocksDBException - if error happens in underlying native library.

IllegalArgumentException - thrown if the number of passed keys, passed values and passed column family handles do not match.

multiGetByteBuffers

public List<ByteBufferGetStatus> multiGetByteBuffers(ReadOptions readOptions,
 List<ColumnFamilyHandle> columnFamilyHandleList,
 List<ByteBuffer> keys,
 List<ByteBuffer> values)
                                              throws RocksDBException

Fetches a list of values for the given list of keys.

Note: Every key needs to have a related column family name in columnFamilyHandleList.

Parameters:

readOptions - Read options

columnFamilyHandleList - List containing ColumnFamilyHandle instances.

keys - list of keys for which values need to be retrieved.

values - list of buffers to return retrieved values in

Returns:

the list of values for the given list of keys

Throws:

RocksDBException - if error happens in underlying native library.

IllegalArgumentException - thrown if the number of passed keys, passed values and passed column family handles do not match.

keyExists

public boolean keyExists(byte[] key)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

key - byte array of a key to search for*

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(byte[] key,
 int offset,
 int len)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

key - byte array of a key to search for

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than "key".length

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ColumnFamilyHandle columnFamilyHandle,
 byte[] key)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - byte array of a key to search for

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 int offset,
 int len)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - byte array of a key to search for

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than "key".length

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ReadOptions readOptions,
 byte[] key)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

readOptions - ReadOptions instance

key - byte array of a key to search for

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ReadOptions readOptions,
 byte[] key,
 int offset,
 int len)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

readOptions - ReadOptions instance

key - byte array of a key to search for

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than "key".length

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions readOptions,
 byte[] key)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

readOptions - ReadOptions instance

key - byte array of a key to search for

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions readOptions,
 byte[] key,
 int offset,
 int len)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

readOptions - ReadOptions instance

key - byte array of a key to search for

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than "key".length

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ByteBuffer key)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

key - ByteBuffer with key. Must be allocated as direct.

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ColumnFamilyHandle columnFamilyHandle,
 ByteBuffer key)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - ByteBuffer with key. Must be allocated as direct.

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ReadOptions readOptions,
 ByteBuffer key)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

readOptions - ReadOptions instance

key - ByteBuffer with key. Must be allocated as direct.

Returns:

true if key exist in database, otherwise false.

keyExists

public boolean keyExists(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions readOptions,
 ByteBuffer key)

Check if a key exists in the database. This method is not as lightweight as keyMayExist but it gives a 100% guarantee of a correct result, whether the key exists or not. Internally it checks if the key may exist and then double checks with read operation that confirms the key exists. This deals with the case where keyMayExist may return a false positive. The code crosses the Java/JNI boundary only once.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

readOptions - ReadOptions instance

key - ByteBuffer with key. Must be allocated as direct.

Returns:

true if key exist in database, otherwise false.

keyMayExist

public boolean keyMayExist(byte[] key,
 Holder<byte[]> valueHolder)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a false negative.

If the caller wants to obtain value when the key is found in memory, then valueHolder must be set.

This check is potentially lighter-weight than invoking get(byte[]). One way to make this lighter weight is to avoid doing any IOs.

Parameters:

key - byte array of a key to search for

valueHolder - non-null to retrieve the value if it is found, or null if the value is not needed. If non-null, upon return of the function, the value will be set if it could be retrieved.

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(byte[] key,
 int offset,
 int len,
 Holder<byte[]> valueHolder)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a false negative.

If the caller wants to obtain value when the key is found in memory, then valueHolder must be set.

This check is potentially lighter-weight than invoking get(byte[], int, int). One way to make this lighter weight is to avoid doing any IOs.

Parameters:

key - byte array of a key to search for

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than "key".length

valueHolder - non-null to retrieve the value if it is found, or null if the value is not needed. If non-null, upon return of the function, the value will be set if it could be retrieved.

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 Holder<byte[]> valueHolder)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a false negative.

If the caller wants to obtain value when the key is found in memory, then valueHolder must be set.

This check is potentially lighter-weight than invoking get(ColumnFamilyHandle,byte[]). One way to make this lighter weight is to avoid doing any IOs.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - byte array of a key to search for

valueHolder - non-null to retrieve the value if it is found, or null if the value is not needed. If non-null, upon return of the function, the value will be set if it could be retrieved.

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(ColumnFamilyHandle columnFamilyHandle,
 byte[] key,
 int offset,
 int len,
 Holder<byte[]> valueHolder)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a false negative.

If the caller wants to obtain value when the key is found in memory, then valueHolder must be set.

This check is potentially lighter-weight than invoking get(ColumnFamilyHandle, byte[], int, int). One way to make this lighter weight is to avoid doing any IOs.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

key - byte array of a key to search for

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than "key".length

valueHolder - non-null to retrieve the value if it is found, or null if the value is not needed. If non-null, upon return of the function, the value will be set if it could be retrieved.

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(ReadOptions readOptions,
 byte[] key,
 Holder<byte[]> valueHolder)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a true negative.

If the caller wants to obtain value when the key is found in memory, then valueHolder must be set.

This check is potentially lighter-weight than invoking get(ReadOptions, byte[]). One way to make this lighter weight is to avoid doing any IOs.

Parameters:

readOptions - ReadOptions instance

key - byte array of a key to search for

valueHolder - non-null to retrieve the value if it is found, or null if the value is not needed. If non-null, upon return of the function, the value will be set if it could be retrieved.

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(ReadOptions readOptions,
 byte[] key,
 int offset,
 int len,
 Holder<byte[]> valueHolder)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a true negative.

If the caller wants to obtain value when the key is found in memory, then valueHolder must be set.

This check is potentially lighter-weight than invoking get(ReadOptions, byte[], int, int). One way to make this lighter weight is to avoid doing any IOs.

Parameters:

readOptions - ReadOptions instance

key - byte array of a key to search for

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than "key".length

valueHolder - non-null to retrieve the value if it is found, or null if the value is not needed. If non-null, upon return of the function, the value will be set if it could be retrieved.

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions readOptions,
 byte[] key,
 Holder<byte[]> valueHolder)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a true negative.

If the caller wants to obtain value when the key is found in memory, then valueHolder must be set.

This check is potentially lighter-weight than invoking get(ColumnFamilyHandle, ReadOptions, byte[]). One way to make this lighter weight is to avoid doing any IOs.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

readOptions - ReadOptions instance

key - byte array of a key to search for

valueHolder - non-null to retrieve the value if it is found, or null if the value is not needed. If non-null, upon return of the function, the value will be set if it could be retrieved.

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions readOptions,
 byte[] key,
 int offset,
 int len,
 Holder<byte[]> valueHolder)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a false negative.

If the caller wants to obtain value when the key is found in memory, then valueHolder must be set.

This check is potentially lighter-weight than invoking get(ColumnFamilyHandle, ReadOptions, byte[], int, int). One way to make this lighter weight is to avoid doing any IOs.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

readOptions - ReadOptions instance

key - byte array of a key to search for

offset - the offset of the "key" array to be used, must be non-negative and no larger than "key".length

len - the length of the "key" array to be used, must be non-negative and no larger than "key".length

valueHolder - non-null to retrieve the value if it is found, or null if the value is not needed. If non-null, upon return of the function, the value will be set if it could be retrieved.

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(ByteBuffer key)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a false negative.

Parameters:

key - bytebuffer containing the value of the key

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(ColumnFamilyHandle columnFamilyHandle,
 ByteBuffer key)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a false negative.

Parameters:

columnFamilyHandle - the ColumnFamilyHandle to look for the key in

key - bytebuffer containing the value of the key

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public boolean keyMayExist(ReadOptions readOptions,
 ByteBuffer key)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a false negative.

Parameters:

readOptions - the ReadOptions to use when reading the key/value

key - bytebuffer containing the value of the key

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public KeyMayExist keyMayExist(ByteBuffer key,
 ByteBuffer value)

If the key definitely does not exist in the database, then this method returns KeyMayExist.KeyMayExistEnum.kNotExist, otherwise if it can with best effort retreive the value, it returns KeyMayExist.KeyMayExistEnum.kExistsWithValue otherwise it returns KeyMayExist.KeyMayExistEnum.kExistsWithoutValue. The choice not to return a value which might exist is at the discretion of the implementation; the only guarantee is that KeyMayExist.KeyMayExistEnum.kNotExist is an assurance that the key does not exist.

Parameters:

key - bytebuffer containing the value of the key

value - bytebuffer which will receive a value if the key exists and a value is known

Returns:

a KeyMayExist object reporting if key may exist and if a value is provided

keyMayExist

public KeyMayExist keyMayExist(ColumnFamilyHandle columnFamilyHandle,
 ByteBuffer key,
 ByteBuffer value)

If the key definitely does not exist in the database, then this method returns KeyMayExist.KeyMayExistEnum.kNotExist, otherwise if it can with best effort retreive the value, it returns KeyMayExist.KeyMayExistEnum.kExistsWithValue otherwise it returns KeyMayExist.KeyMayExistEnum.kExistsWithoutValue. The choice not to return a value which might exist is at the discretion of the implementation; the only guarantee is that KeyMayExist.KeyMayExistEnum.kNotExist is an assurance that the key does not exist.

Parameters:

columnFamilyHandle - the ColumnFamilyHandle to look for the key in

key - bytebuffer containing the value of the key

value - bytebuffer which will receive a value if the key exists and a value is known

Returns:

a KeyMayExist object reporting if key may exist and if a value is provided

keyMayExist

public KeyMayExist keyMayExist(ReadOptions readOptions,
 ByteBuffer key,
 ByteBuffer value)

If the key definitely does not exist in the database, then this method returns KeyMayExist.KeyMayExistEnum.kNotExist, otherwise if it can with best effort retreive the value, it returns KeyMayExist.KeyMayExistEnum.kExistsWithValue otherwise it returns KeyMayExist.KeyMayExistEnum.kExistsWithoutValue. The choice not to return a value which might exist is at the discretion of the implementation; the only guarantee is that KeyMayExist.KeyMayExistEnum.kNotExist is an assurance that the key does not exist.

Parameters:

readOptions - the ReadOptions to use when reading the key/value

key - bytebuffer containing the value of the key

value - bytebuffer which will receive a value if the key exists and a value is known

Returns:

a KeyMayExist object reporting if key may exist and if a value is provided

keyMayExist

public boolean keyMayExist(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions readOptions,
 ByteBuffer key)

If the key definitely does not exist in the database, then this method returns false, otherwise it returns true if the key might exist. That is to say that this method is probabilistic and may return false positives, but never a false negative.

Parameters:

columnFamilyHandle - the ColumnFamilyHandle to look for the key in

readOptions - the ReadOptions to use when reading the key/value

key - bytebuffer containing the value of the key

Returns:

false if the key definitely does not exist in the database, otherwise true.

keyMayExist

public KeyMayExist keyMayExist(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions readOptions,
 ByteBuffer key,
 ByteBuffer value)

If the key definitely does not exist in the database, then this method returns KeyMayExist.KeyMayExistEnum.kNotExist, otherwise if it can with best effort retreive the value, it returns KeyMayExist.KeyMayExistEnum.kExistsWithValue otherwise it returns KeyMayExist.KeyMayExistEnum.kExistsWithoutValue. The choice not to return a value which might exist is at the discretion of the implementation; the only guarantee is that KeyMayExist.KeyMayExistEnum.kNotExist is an assurance that the key does not exist.

Parameters:

columnFamilyHandle - the ColumnFamilyHandle to look for the key in

readOptions - the ReadOptions to use when reading the key/value

key - bytebuffer containing the value of the key

value - bytebuffer which will receive a value if the key exists and a value is known

Returns:

a KeyMayExist object reporting if key may exist and if a value is provided

newIterator

public RocksIterator newIterator()

Return a heap-allocated iterator over the contents of the database. The result of newIterator() is initially invalid (caller must call one of the Seek methods on the iterator before using it).

Caller should close the iterator when it is no longer needed. The returned iterator should be closed before this db is closed.

Returns:

instance of iterator object.

newIterator

public RocksIterator newIterator(ReadOptions readOptions)

Return a heap-allocated iterator over the contents of the database. The result of newIterator() is initially invalid (caller must call one of the Seek methods on the iterator before using it).

Caller should close the iterator when it is no longer needed. The returned iterator should be closed before this db is closed.

Parameters:

readOptions - ReadOptions instance.

Returns:

instance of iterator object.

newIterator

public RocksIterator newIterator(ColumnFamilyHandle columnFamilyHandle)

Return a heap-allocated iterator over the contents of a ColumnFamily. The result of newIterator() is initially invalid (caller must call one of the Seek methods on the iterator before using it).

Caller should close the iterator when it is no longer needed. The returned iterator should be closed before this db is closed.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

Returns:

instance of iterator object.

newIterator

public RocksIterator newIterator(ColumnFamilyHandle columnFamilyHandle,
 ReadOptions readOptions)

Return a heap-allocated iterator over the contents of a ColumnFamily. The result of newIterator() is initially invalid (caller must call one of the Seek methods on the iterator before using it).

Caller should close the iterator when it is no longer needed. The returned iterator should be closed before this db is closed.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

readOptions - ReadOptions instance.

Returns:

instance of iterator object.

newIterators

public List<RocksIterator> newIterators(List<ColumnFamilyHandle> columnFamilyHandleList)
                                 throws RocksDBException

Returns iterators from a consistent database state across multiple column families. Iterators are heap allocated and need to be deleted before the db is deleted

Parameters:

columnFamilyHandleList - List containing ColumnFamilyHandle instances.

Returns:

List containing RocksIterator instances

Throws:

RocksDBException - thrown if error happens in underlying native library.

newIterators

public List<RocksIterator> newIterators(List<ColumnFamilyHandle> columnFamilyHandleList,
 ReadOptions readOptions)
                                 throws RocksDBException

Returns iterators from a consistent database state across multiple column families. Iterators are heap allocated and need to be deleted before the db is deleted

Parameters:

columnFamilyHandleList - List containing ColumnFamilyHandle instances.

readOptions - ReadOptions instance.

Returns:

List containing RocksIterator instances

Throws:

RocksDBException - thrown if error happens in underlying native library.

getSnapshot

public Snapshot getSnapshot()

Return a handle to the current DB state. Iterators created with this handle will all observe a stable snapshot of the current DB state. The caller must call ReleaseSnapshot(result) when the snapshot is no longer needed.

nullptr will be returned if the DB fails to take a snapshot or does not support snapshot.

Returns:

Snapshot Snapshot instance

releaseSnapshot

public void releaseSnapshot(Snapshot snapshot)

Release a previously acquired snapshot.

The caller must not use "snapshot" after this call.

Parameters:

snapshot - Snapshot instance

getProperty

public String getProperty(ColumnFamilyHandle columnFamilyHandle,
 String property)
                   throws RocksDBException

DB implements can export properties about their state via this method on a per column family level.

If property is a valid property understood by this DB implementation, fills value with its current value and returns true. Otherwise returns false.

Valid property names include:

• "rocksdb.num-files-at-level<N>" - return the number of files at level <N>, where <N> is an ASCII representation of a level number (e.g. "0").
• "rocksdb.stats" - returns a multi-line string that describes statistics about the internal operation of the DB.
• "rocksdb.sstables" - returns a multi-line string that describes all of the sstables that make up the db contents.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance, or null for the default column family.

property - to be fetched. See above for examples

Returns:

property value

Throws:

RocksDBException - thrown if error happens in underlying native library.

getProperty

public String getProperty(String property)
                   throws RocksDBException

DB implementations can export properties about their state via this method. If "property" is a valid property understood by this DB implementation, fills "*value" with its current value and returns true. Otherwise returns false.

Valid property names include:

• "rocksdb.num-files-at-level<N>" - return the number of files at level <N>, where <N> is an ASCII representation of a level number (e.g. "0").
• "rocksdb.stats" - returns a multi-line string that describes statistics about the internal operation of the DB.
• "rocksdb.sstables" - returns a multi-line string that describes all of the sstables that make up the db contents.

Parameters:

property - to be fetched. See above for examples

Returns:

property value

Throws:

RocksDBException - thrown if error happens in underlying native library.

getMapProperty

public Map<String,String> getMapProperty(String property)
                                  throws RocksDBException

Gets a property map.

Parameters:

property - to be fetched.

Returns:

the property map

Throws:

RocksDBException - if an error happens in the underlying native code.

getMapProperty

public Map<String,String> getMapProperty(ColumnFamilyHandle columnFamilyHandle,
 String property)
                                  throws RocksDBException

Gets a property map.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance, or null for the default column family.

property - to be fetched.

Returns:

the property map

Throws:

RocksDBException - if an error happens in the underlying native code.

getLongProperty

public long getLongProperty(String property)
                     throws RocksDBException

Similar to GetProperty(), but only works for a subset of properties whose return value is a numerical value. Return the value as long.

Note: As the returned property is of type uint64_t on C++ side the returning value can be negative because Java supports in Java 7 only signed long values.

Java 7: To mitigate the problem of the non existent unsigned long tpye, values should be encapsulated using BigInteger to reflect the correct value. The correct behavior is guaranteed if 2^64 is added to negative values.

Java 8: In Java 8 the value should be treated as unsigned long using provided methods of type Long.

Parameters:

property - to be fetched.

Returns:

numerical property value.

Throws:

RocksDBException - if an error happens in the underlying native code.

getLongProperty

public long getLongProperty(ColumnFamilyHandle columnFamilyHandle,
 String property)
                     throws RocksDBException

Similar to GetProperty(), but only works for a subset of properties whose return value is a numerical value. Return the value as long.

Note: As the returned property is of type uint64_t on C++ side the returning value can be negative because Java supports in Java 7 only signed long values.

Java 7: To mitigate the problem of the non existent unsigned long tpye, values should be encapsulated using BigInteger to reflect the correct value. The correct behavior is guaranteed if 2^64 is added to negative values.

Java 8: In Java 8 the value should be treated as unsigned long using provided methods of type Long.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance, or null for the default column family

property - to be fetched.

Returns:

numerical property value

Throws:

RocksDBException - if an error happens in the underlying native code.

resetStats

public void resetStats()
                throws RocksDBException

Reset internal stats for DB and all column families.

Note this doesn't reset Options.statistics() as it is not owned by DB.

Throws:

RocksDBException - if an error occurs whilst reseting the stats

getAggregatedLongProperty

public long getAggregatedLongProperty(String property)
                               throws RocksDBException

Return sum of the getLongProperty of all the column families

Note: As the returned property is of type uint64_t on C++ side the returning value can be negative because Java supports in Java 7 only signed long values.

Java 7: To mitigate the problem of the non existent unsigned long tpye, values should be encapsulated using BigInteger to reflect the correct value. The correct behavior is guaranteed if 2^64 is added to negative values.

Java 8: In Java 8 the value should be treated as unsigned long using provided methods of type Long.

Parameters:

property - to be fetched.

Returns:

numerical property value

Throws:

RocksDBException - if an error happens in the underlying native code.

getApproximateSizes

public long[] getApproximateSizes(ColumnFamilyHandle columnFamilyHandle,
 List<Range> ranges,
 SizeApproximationFlag... sizeApproximationFlags)

Get the approximate file system space used by keys in each range.

Note that the returned sizes measure file system space usage, so if the user data compresses by a factor of ten, the returned sizes will be one-tenth the size of the corresponding user data size.

If sizeApproximationFlags defines whether the returned size should include the recently written data in the mem-tables (if the mem-table type supports it), data serialized to disk, or both.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance, or null for the default column family

ranges - the ranges over which to approximate sizes

sizeApproximationFlags - flags to determine what to include in the approximation.

Returns:

the sizes

getApproximateSizes

public long[] getApproximateSizes(List<Range> ranges,
 SizeApproximationFlag... sizeApproximationFlags)

Get the approximate file system space used by keys in each range for the default column family.

Note that the returned sizes measure file system space usage, so if the user data compresses by a factor of ten, the returned sizes will be one-tenth the size of the corresponding user data size.

If sizeApproximationFlags defines whether the returned size should include the recently written data in the mem-tables (if the mem-table type supports it), data serialized to disk, or both.

Parameters:

ranges - the ranges over which to approximate sizes

sizeApproximationFlags - flags to determine what to include in the approximation.

Returns:

the sizes.

getApproximateMemTableStats

public RocksDB.CountAndSize getApproximateMemTableStats(ColumnFamilyHandle columnFamilyHandle,
 Range range)

This method is similar to getApproximateSizes(ColumnFamilyHandle, List, SizeApproximationFlag...), except that it returns approximate number of records and size in memtables.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance, or null for the default column family

range - the ranges over which to get the memtable stats

Returns:

the count and size for the range

getApproximateMemTableStats

public RocksDB.CountAndSize getApproximateMemTableStats(Range range)

This method is similar to getApproximateSizes(ColumnFamilyHandle, List, SizeApproximationFlag...), except that it returns approximate number of records and size in memtables.

Parameters:

range - the ranges over which to get the memtable stats

Returns:

the count and size for the range

compactRange

public void compactRange()
                  throws RocksDBException

Range compaction of database.

Note: After the database has been compacted, all data will have been pushed down to the last level containing any data.

See also

• compactRange(byte[], byte[])

Throws:

RocksDBException - thrown if an error occurs within the native part of the library.

compactRange

public void compactRange(ColumnFamilyHandle columnFamilyHandle)
                  throws RocksDBException

Range compaction of column family.

Note: After the database has been compacted, all data will have been pushed down to the last level containing any data.

See also

• compactRange(ColumnFamilyHandle, byte[], byte[])

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance, or null for the default column family.

Throws:

RocksDBException - thrown if an error occurs within the native part of the library.

compactRange

public void compactRange(byte[] begin,
 byte[] end)
                  throws RocksDBException

Range compaction of database.

Note: After the database has been compacted, all data will have been pushed down to the last level containing any data.

See also

• compactRange()

Parameters:

begin - start of key range (included in range)

end - end of key range (excluded from range)

Throws:

RocksDBException - thrown if an error occurs within the native part of the library.

compactRange

public void compactRange(ColumnFamilyHandle columnFamilyHandle,
 byte[] begin,
 byte[] end)
                  throws RocksDBException

Range compaction of column family.

Note: After the database has been compacted, all data will have been pushed down to the last level containing any data.

See also

• compactRange(ColumnFamilyHandle)

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance, or null for the default column family.

begin - start of key range (included in range)

end - end of key range (excluded from range)

Throws:

RocksDBException - thrown if an error occurs within the native part of the library.

compactRange

public void compactRange(ColumnFamilyHandle columnFamilyHandle,
 byte[] begin,
 byte[] end,
 CompactRangeOptions compactRangeOptions)
                  throws RocksDBException

Range compaction of column family.

Note: After the database has been compacted, all data will have been pushed down to the last level containing any data.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance.

begin - start of key range (included in range)

end - end of key range (excluded from range)

compactRangeOptions - options for the compaction

Throws:

RocksDBException - thrown if an error occurs within the native part of the library.

clipColumnFamily

public void clipColumnFamily(ColumnFamilyHandle columnFamilyHandle,
 byte[] beginKey,
 byte[] endKey)
                      throws RocksDBException

ClipColumnFamily() will clip the entries in the CF according to the range [begin_key, end_key). Returns OK on success, and a non-OK status on error. Any entries outside this range will be completely deleted (including tombstones).

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance

beginKey - First key to clip within database (inclusive)

endKey - Last key to clip within database (exclusive)

Throws:

RocksDBException - thrown if error happens in underlying native library.

setOptions

public void setOptions(ColumnFamilyHandle columnFamilyHandle,
 MutableColumnFamilyOptions mutableColumnFamilyOptions)
                throws RocksDBException

Change the options for the column family handle.

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance, or null for the default column family.

mutableColumnFamilyOptions - the options.

Throws:

RocksDBException - if an error occurs whilst setting the options

setPerfLevel

public void setPerfLevel(PerfLevel level)

Set performance level for rocksdb performance measurement.

Parameters:

level -

Throws:

IllegalArgumentException - for UNINITIALIZED and OUT_OF_BOUNDS values as they can't be used for settings.

getPerfLevel

public PerfLevel getPerfLevel()

Return current performance level measurement settings.

Returns:

getPerfContext

public PerfContext getPerfContext()

Return perf context bound to this thread.

Returns:

getOptions

public MutableColumnFamilyOptions.MutableColumnFamilyOptionsBuilder getOptions(ColumnFamilyHandle columnFamilyHandle)
                                                                        throws RocksDBException

Get the options for the column family handle

Parameters:

columnFamilyHandle - ColumnFamilyHandle instance, or null for the default column family.

Returns:

the options parsed from the options string return by RocksDB

Throws:

RocksDBException - if an error occurs while getting the options string, or parsing the resulting options string into options

getOptions

public MutableColumnFamilyOptions.MutableColumnFamilyOptionsBuilder getOptions()
                                                                        throws RocksDBException

Default column family options

Returns:

the options parsed from the options string return by RocksDB

Throws:

RocksDBException - if an error occurs while getting the options string, or parsing the resulting options string into options

getDBOptions

public MutableDBOptions.MutableDBOptionsBuilder getDBOptions()
                                                      throws RocksDBException

Get the database options

Returns:

the DB options parsed from the options string return by RocksDB

Throws:

RocksDBException - if an error occurs while getting the options string, or parsing the resulting options string into options

setOptions

public void setOptions(MutableColumnFamilyOptions mutableColumnFamilyOptions)
                throws RocksDBException

Change the options for the default column family handle.

Parameters:

mutableColumnFamilyOptions - the options.

Throws:

RocksDBException - if an error occurs whilst setting the options

setDBOptions

public void setDBOptions(MutableDBOptions mutableDBoptions)
                  throws RocksDBException

Set the options for the column family handle.

Parameters:

mutableDBoptions - the options.

Throws:

RocksDBException - if an error occurs whilst setting the options

compactFiles

public List<String> compactFiles(CompactionOptions compactionOptions,
 List<String> inputFileNames,
 int outputLevel,
 int outputPathId,
 CompactionJobInfo compactionJobInfo)
                          throws RocksDBException

Takes a list of files specified by file names and compacts them to the specified level.

Note that the behavior is different from compactRange(ColumnFamilyHandle, byte[], byte[]) in that CompactFiles() performs the compaction job using the CURRENT thread.

Parameters:

compactionOptions - compaction options

inputFileNames - the name of the files to compact

outputLevel - the level to which they should be compacted

outputPathId - the id of the output path, or -1

compactionJobInfo - the compaction job info, this parameter will be updated with the info from compacting the files, can just be null if you don't need it.

Returns:

the list of compacted files

Throws:

RocksDBException - if an error occurs during compaction

compactFiles

public List<String> compactFiles(CompactionOptions compactionOptions,
 ColumnFamilyHandle columnFamilyHandle,
 List<String> inputFileNames,
 int outputLevel,
 int outputPathId,
 CompactionJobInfo compactionJobInfo)
                          throws RocksDBException

Takes a list of files specified by file names and compacts them to the specified level.

Note that the behavior is different from compactRange(ColumnFamilyHandle, byte[], byte[]) in that CompactFiles() performs the compaction job using the CURRENT thread.

Parameters:

compactionOptions - compaction options

columnFamilyHandle - columnFamilyHandle, or null for the default column family

inputFileNames - the name of the files to compact

outputLevel - the level to which they should be compacted

outputPathId - the id of the output path, or -1

compactionJobInfo - the compaction job info, this parameter will be updated with the info from compacting the files, can just be null if you don't need it.

Returns:

the list of compacted files

Throws:

RocksDBException - if an error occurs during compaction

cancelAllBackgroundWork

public void cancelAllBackgroundWork(boolean wait)

This function will cancel all currently running background processes.

Parameters:

wait - if true, wait for all background work to be cancelled before returning.

pauseBackgroundWork

public void pauseBackgroundWork()
                         throws RocksDBException

This function will wait until all currently running background processes finish. After it returns, no background process will be run until continueBackgroundWork() is called

Throws:

RocksDBException - if an error occurs when pausing background work

continueBackgroundWork

public void continueBackgroundWork()
                            throws RocksDBException

Resumes background work which was suspended by previously calling pauseBackgroundWork()

Throws:

RocksDBException - if an error occurs when resuming background work

enableAutoCompaction

public void enableAutoCompaction(List<ColumnFamilyHandle> columnFamilyHandles)
                          throws RocksDBException

Enable automatic compactions for the given column families if they were previously disabled.

The function will first set the ColumnFamilyOptions.disableAutoCompactions() option for each column family to false, after which it will schedule a flush/compaction.

NOTE: Setting disableAutoCompactions to 'false' through setOptions(ColumnFamilyHandle, MutableColumnFamilyOptions) does NOT schedule a flush/compaction afterwards, and only changes the parameter itself within the column family option.

Parameters:

columnFamilyHandles - the column family handles

Throws:

RocksDBException - if an error occurs whilst enabling auto-compaction

numberLevels

public int numberLevels()

Number of levels used for this DB.

Returns:

the number of levels

numberLevels

public int numberLevels(ColumnFamilyHandle columnFamilyHandle)

Number of levels used for a column family in this DB.

Parameters:

columnFamilyHandle - the column family handle, or null for the default column family

Returns:

the number of levels

maxMemCompactionLevel

public int maxMemCompactionLevel()

Maximum level to which a new compacted memtable is pushed if it does not create overlap.

Returns:

the maximum level

maxMemCompactionLevel

public int maxMemCompactionLevel(ColumnFamilyHandle columnFamilyHandle)

Maximum level to which a new compacted memtable is pushed if it does not create overlap.

Parameters:

columnFamilyHandle - the column family handle

Returns:

the maximum level

level0StopWriteTrigger

public int level0StopWriteTrigger()

Number of files in level-0 that would stop writes.

Returns:

the number of files

level0StopWriteTrigger

public int level0StopWriteTrigger(ColumnFamilyHandle columnFamilyHandle)

Number of files in level-0 that would stop writes.

Parameters:

columnFamilyHandle - the column family handle

Returns:

the number of files

getName

public String getName()

Get DB name -- the exact same name that was provided as an argument to as path to open(Options, String).

Returns:

the DB name

getEnv

public Env getEnv()

Get the Env object from the DB

Returns:

the env

flush

public void flush(FlushOptions flushOptions)
           throws RocksDBException

Flush all memory table data.

Note: it must be ensured that the FlushOptions instance is not GC'ed before this method finishes. If the wait parameter is set to false, flush processing is asynchronous.

Parameters:

flushOptions - FlushOptions instance.

Throws:

RocksDBException - thrown if an error occurs within the native part of the library.

flush

public void flush(FlushOptions flushOptions,
 ColumnFamilyHandle columnFamilyHandle)
           throws RocksDBException

Flush all memory table data.

Note: it must be ensured that the FlushOptions instance is not GC'ed before this method finishes. If the wait parameter is set to false, flush processing is asynchronous.

Parameters:

flushOptions - FlushOptions instance.

columnFamilyHandle - ColumnFamilyHandle instance.

Throws:

RocksDBException - thrown if an error occurs within the native part of the library.

flush

public void flush(FlushOptions flushOptions,
 List<ColumnFamilyHandle> columnFamilyHandles)
           throws RocksDBException

Flushes multiple column families.

If atomic flush is not enabled, this is equivalent to calling flush(FlushOptions, ColumnFamilyHandle) multiple times.

If atomic flush is enabled, this will flush all column families specified up to the latest sequence number at the time when flush is requested.

Parameters:

flushOptions - FlushOptions instance.

columnFamilyHandles - column family handles.

Throws:

RocksDBException - thrown if an error occurs within the native part of the library.

flushWal

public void flushWal(boolean sync)
              throws RocksDBException

Flush the WAL memory buffer to the file. If sync is true, it calls syncWal() afterwards.

Parameters:

sync - true to also fsync to disk.

Throws:

RocksDBException - if an error occurs whilst flushing

syncWal

public void syncWal()
             throws RocksDBException

Sync the WAL.

Note that write(WriteOptions, WriteBatch) followed by #syncWal() is not exactly the same as write(WriteOptions, WriteBatch) with WriteOptions.sync() set to true; In the latter case the changes won't be visible until the sync is done.

Currently only works if Options.allowMmapWrites() is set to false.

Throws:

RocksDBException - if an error occurs whilst syncing

getLatestSequenceNumber

public long getLatestSequenceNumber()

The sequence number of the most recent transaction.

Returns:

sequence number of the most recent transaction.

disableFileDeletions

public void disableFileDeletions()
                          throws RocksDBException

Prevent file deletions. Compactions will continue to occur, but no obsolete files will be deleted. Calling this multiple times have the same effect as calling it once.

Throws:

RocksDBException - thrown if operation was not performed successfully.

enableFileDeletions

public void enableFileDeletions()
                         throws RocksDBException

EnableFileDeletions will only enable file deletion after it's been called at least as many times as DisableFileDeletions(), enabling the two methods to be called by two threads concurrently without synchronization -- i.e., file deletions will be enabled only after both threads call EnableFileDeletions()

Throws:

RocksDBException - thrown if operation was not performed successfully.

getLiveFiles

public RocksDB.LiveFiles getLiveFiles()
                               throws RocksDBException

Retrieve the list of all files in the database after flushing the memtable.

See getLiveFiles(boolean).

Returns:

the live files

Throws:

RocksDBException - if an error occurs whilst retrieving the list of live files

getLiveFiles

public RocksDB.LiveFiles getLiveFiles(boolean flushMemtable)
                               throws RocksDBException

Retrieve the list of all files in the database.

In case you have multiple column families, even if flushMemtable is true, you still need to call getSortedWalFiles() after #getLiveFiles(boolean) to compensate for new data that arrived to already-flushed column families while other column families were flushing.

NOTE: Calling #getLiveFiles(boolean) followed by getSortedWalFiles() can generate a lossless backup.

Parameters:

flushMemtable - set to true to flush before recoding the live files. Setting to false is useful when we don't want to wait for flush which may have to wait for compaction to complete taking an indeterminate time.

Returns:

the live files

Throws:

RocksDBException - if an error occurs whilst retrieving the list of live files

getSortedWalFiles

public List<LogFile> getSortedWalFiles()
                                throws RocksDBException

Retrieve the sorted list of all wal files with earliest file first.

Returns:

the log files

Throws:

RocksDBException - if an error occurs whilst retrieving the list of sorted WAL files

getUpdatesSince

public TransactionLogIterator getUpdatesSince(long sequenceNumber)
                                       throws RocksDBException

Returns an iterator that is positioned at a write-batch containing seq_number. If the sequence number is non existent, it returns an iterator at the first available seq_no after the requested seq_no.

Must set WAL_ttl_seconds or WAL_size_limit_MB to large values to use this api, else the WAL files will get cleared aggressively and the iterator might keep getting invalid before an update is read.

Parameters:

sequenceNumber - sequence number offset

Returns:

TransactionLogIterator instance.

Throws:

RocksDBException - if iterator cannot be retrieved from native-side.

deleteFile

public void deleteFile(String name)
                throws RocksDBException

Delete the file name from the db directory and update the internal state to reflect that. Supports deletion of sst and log files only. 'name' must be path relative to the db directory. eg. 000001.sst, /archive/000003.log

Parameters:

name - the file name

Throws:

RocksDBException - if an error occurs whilst deleting the file

getLiveFilesMetaData

public List<LiveFileMetaData> getLiveFilesMetaData()

Gets a list of all table files metadata.

Returns:

table files metadata.

getColumnFamilyMetaData

public ColumnFamilyMetaData getColumnFamilyMetaData(ColumnFamilyHandle columnFamilyHandle)

Obtains the meta data of the specified column family of the DB.

Parameters:

columnFamilyHandle - the column family

Returns:

the column family metadata

getColumnFamilyMetaData

public ColumnFamilyMetaData getColumnFamilyMetaData()

Obtains the meta data of the default column family of the DB.

Returns:

the column family metadata

ingestExternalFile

public void ingestExternalFile(List<String> filePathList,
 IngestExternalFileOptions ingestExternalFileOptions)
                        throws RocksDBException

ingestExternalFile will load a list of external SST files (1) into the DB We will try to find the lowest possible level that the file can fit in, and ingest the file into this level (2). A file that have a key range that overlap with the memtable key range will require us to Flush the memtable first before ingesting the file.

(1) External SST files can be created using SstFileWriter (2) We will try to ingest the files to the lowest possible level even if the file compression doesn't match the level compression

Parameters:

filePathList - The list of files to ingest

ingestExternalFileOptions - the options for the ingestion

Throws:

RocksDBException - thrown if error happens in underlying native library.

ingestExternalFile

public void ingestExternalFile(ColumnFamilyHandle columnFamilyHandle,
 List<String> filePathList,
 IngestExternalFileOptions ingestExternalFileOptions)
                        throws RocksDBException

ingestExternalFile will load a list of external SST files (1) into the DB We will try to find the lowest possible level that the file can fit in, and ingest the file into this level (2). A file that have a key range that overlap with the memtable key range will require us to Flush the memtable first before ingesting the file.

(1) External SST files can be created using SstFileWriter (2) We will try to ingest the files to the lowest possible level even if the file compression doesn't match the level compression

Parameters:

columnFamilyHandle - The column family for the ingested files

filePathList - The list of files to ingest

ingestExternalFileOptions - the options for the ingestion

Throws:

RocksDBException - thrown if error happens in underlying native library.

verifyChecksum

public void verifyChecksum()
                    throws RocksDBException

Verify checksum

Throws:

RocksDBException - if the checksum is not valid

getDefaultColumnFamily

public ColumnFamilyHandle getDefaultColumnFamily()

Gets the handle for the default column family

Returns:

The handle of the default column family

makeDefaultColumnFamilyHandle

protected ColumnFamilyHandle makeDefaultColumnFamilyHandle()

Create a handle for the default CF on open

Returns:

the default family handle

getPropertiesOfAllTables

public Map<String,TableProperties> getPropertiesOfAllTables(ColumnFamilyHandle columnFamilyHandle)
                                                     throws RocksDBException

Get the properties of all tables.

Parameters:

columnFamilyHandle - the column family handle, or null for the default column family.

Returns:

the properties

Throws:

RocksDBException - if an error occurs whilst getting the properties

getPropertiesOfAllTables

public Map<String,TableProperties> getPropertiesOfAllTables()
                                                     throws RocksDBException

Get the properties of all tables in the default column family.

Returns:

the properties

Throws:

RocksDBException - if an error occurs whilst getting the properties

getPropertiesOfTablesInRange

public Map<String,TableProperties> getPropertiesOfTablesInRange(ColumnFamilyHandle columnFamilyHandle,
 List<Range> ranges)
                                                         throws RocksDBException

Get the properties of tables in range.

Parameters:

columnFamilyHandle - the column family handle, or null for the default column family.

ranges - the ranges over which to get the table properties

Returns:

the properties

Throws:

RocksDBException - if an error occurs whilst getting the properties

getPropertiesOfTablesInRange

public Map<String,TableProperties> getPropertiesOfTablesInRange(List<Range> ranges)
                                                         throws RocksDBException

Get the properties of tables in range for the default column family.

Parameters:

ranges - the ranges over which to get the table properties

Returns:

the properties

Throws:

RocksDBException - if an error occurs whilst getting the properties

suggestCompactRange

public Range suggestCompactRange(ColumnFamilyHandle columnFamilyHandle)
                          throws RocksDBException

Suggest the range to compact.

Parameters:

columnFamilyHandle - the column family handle, or null for the default column family.

Returns:

the suggested range.

Throws:

RocksDBException - if an error occurs whilst suggesting the range

suggestCompactRange

public Range suggestCompactRange()
                          throws RocksDBException

Suggest the range to compact for the default column family.

Returns:

the suggested range.

Throws:

RocksDBException - if an error occurs whilst suggesting the range

promoteL0

public void promoteL0(ColumnFamilyHandle columnFamilyHandle,
 int targetLevel)
               throws RocksDBException

Promote L0.

Parameters:

columnFamilyHandle - the column family handle, or null for the default column family.

targetLevel - the target level for L0

Throws:

RocksDBException - if an error occurs whilst promoting L0

promoteL0

public void promoteL0(int targetLevel)
               throws RocksDBException

Promote L0 for the default column family.

Parameters:

targetLevel - the target level for L0

Throws:

RocksDBException - if an error occurs whilst promoting L0

startTrace

public void startTrace(TraceOptions traceOptions,
 AbstractTraceWriter traceWriter)
                throws RocksDBException

Trace DB operations.

Use endTrace() to stop tracing.

Parameters:

traceOptions - the options

traceWriter - the trace writer

Throws:

RocksDBException - if an error occurs whilst starting the trace

endTrace

public void endTrace()
              throws RocksDBException

Stop tracing DB operations.

See startTrace(TraceOptions, AbstractTraceWriter)

Throws:

RocksDBException - if an error occurs whilst ending the trace

tryCatchUpWithPrimary

public void tryCatchUpWithPrimary()
                           throws RocksDBException

Make the secondary instance catch up with the primary by tailing and replaying the MANIFEST and WAL of the primary. Column families created by the primary after the secondary instance starts will be ignored unless the secondary instance closes and restarts with the newly created column families. Column families that exist before secondary instance starts and dropped by the primary afterwards will be marked as dropped. However, as long as the secondary instance does not delete the corresponding column family handles, the data of the column family is still accessible to the secondary.

Throws:

RocksDBException - thrown if error happens in underlying native library.

deleteFilesInRanges

public void deleteFilesInRanges(ColumnFamilyHandle columnFamily,
 List<byte[]> ranges,
 boolean includeEnd)
                         throws RocksDBException

Delete files in multiple ranges at once. Delete files in a lot of ranges one at a time can be slow, use this API for better performance in that case.

Parameters:

columnFamily - - The column family for operation (null for default)

ranges - - pairs of ranges (from1, to1, from2, to2, ...)

includeEnd - - Whether ranges should include end

Throws:

RocksDBException - thrown if error happens in underlying native library.

destroyDB

public static void destroyDB(String path,
 Options options)
                      throws RocksDBException

Static method to destroy the contents of the specified database. Be very careful using this method.

Parameters:

path - the path to the Rocksdb database.

options - Options instance.

Throws:

RocksDBException - thrown if error happens in underlying native library.

storeOptionsInstance

protected void storeOptionsInstance(DBOptionsInterface<?> options)

storeDefaultColumnFamilyHandle

protected void storeDefaultColumnFamilyHandle(ColumnFamilyHandle columnFamilyHandle)

disposeInternal

protected void disposeInternal(long handle)

Specified by:

disposeInternal in class RocksObject