org.rocksdb

Class HashSkipListMemTableConfig

java.lang.Object

org.rocksdb.MemTableConfig

org.rocksdb.HashSkipListMemTableConfig

public class HashSkipListMemTableConfig
extends MemTableConfig

The config for hash skip-list mem-table representation. Such mem-table representation contains a fix-sized array of buckets, where each bucket points to a skiplist (or null if the bucket is empty). Note that since this mem-table representation relies on the key prefix, it is required to invoke one of the usePrefixExtractor functions to specify how to extract key prefix given a key. If proper prefix-extractor is not set, then RocksDB will use the default memtable representation (SkipList) instead and post a warning in the LOG.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_BRANCHING_FACTOR
static int	DEFAULT_BUCKET_COUNT
static int	DEFAULT_HEIGHT

Constructor Summary

Constructors

Constructor and Description
HashSkipListMemTableConfig() HashSkipListMemTableConfig constructor

Method Summary

Modifier and Type	Method and Description
int	branchingFactor()
long	bucketCount()
int	height()
protected long	newMemTableFactoryHandle() This function should only be called by Options.setMemTableConfig(), which will create a c++ shared-pointer to the c++ MemTableRepFactory that associated with the Java MemTableConfig.
HashSkipListMemTableConfig	setBranchingFactor(int bf) Set the branching factor used in the hash skip-list memtable.
HashSkipListMemTableConfig	setBucketCount(long count) Set the number of hash buckets used in the hash skiplist memtable.
HashSkipListMemTableConfig	setHeight(int height) Set the height of the skip list.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_BUCKET_COUNT

public static final int DEFAULT_BUCKET_COUNT

See Also:

Constant Field Values

DEFAULT_BRANCHING_FACTOR

public static final int DEFAULT_BRANCHING_FACTOR

See Also:

Constant Field Values

DEFAULT_HEIGHT

public static final int DEFAULT_HEIGHT

See Also:

Constant Field Values

Constructor Detail

HashSkipListMemTableConfig

public HashSkipListMemTableConfig()

HashSkipListMemTableConfig constructor

Method Detail

setBucketCount

public HashSkipListMemTableConfig setBucketCount(long count)

Set the number of hash buckets used in the hash skiplist memtable. Default = 1000000.

Parameters:

count - the number of hash buckets used in the hash skiplist memtable.

Returns:

the reference to the current HashSkipListMemTableConfig.

bucketCount

public long bucketCount()

Returns:

the number of hash buckets

setHeight

public HashSkipListMemTableConfig setHeight(int height)

Set the height of the skip list. Default = 4.

Parameters:

height - height to set.

Returns:

the reference to the current HashSkipListMemTableConfig.

height

public int height()

Returns:

the height of the skip list.

setBranchingFactor

public HashSkipListMemTableConfig setBranchingFactor(int bf)

Set the branching factor used in the hash skip-list memtable. This factor controls the probabilistic size ratio between adjacent links in the skip list.

Parameters:

bf - the probabilistic size ratio between adjacent link lists in the skip list.

Returns:

the reference to the current HashSkipListMemTableConfig.

branchingFactor

public int branchingFactor()

Returns:

branching factor, the probabilistic size ratio between adjacent links in the skip list.

newMemTableFactoryHandle

protected long newMemTableFactoryHandle()

Description copied from class: MemTableConfig

This function should only be called by Options.setMemTableConfig(), which will create a c++ shared-pointer to the c++ MemTableRepFactory that associated with the Java MemTableConfig.

Specified by:

newMemTableFactoryHandle in class MemTableConfig

Returns:

native handle address to native memory table instance.

See Also:

Options.setMemTableConfig(MemTableConfig)