rocksdb/java/org/rocksdb/HashLinkedListMemTableConfig.java
Yueh-Hsuan Chiang ef8b8a8ef6 [Java] Add Java bindings for memtables and sst format.
Summary:
Add Java bindings for memtables and sst format.  Specifically,
add two abstract Java classses --- MemTableConfig and SstFormatConfig.
Each MemTable / SST implementation should has its own config class
extends MemTableConfig / SstFormatConfig respectively and pass it
to Options via setMemTableConfig / setSstConfig.

Test Plan:
make rocksdbjava
make jdb_test
make jdb_bench
java/jdb_bench.sh \
  --benchmarks=fillseq,readrandom,readwhilewriting \
  --memtablerep=hash_skiplist \
  --use_plain_table=1 \
  --key_size=20 \
  --prefix_size=12 \
  --value_size=100 \
  --cache_size=17179869184 \
  --disable_wal=0 \
  --sync=0 \

Reviewers: haobo, ankgup87, sdong

Reviewed By: haobo

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D17997
2014-04-21 15:40:46 -07:00

53 lines
1.5 KiB
Java

package org.rocksdb;
/**
* The config for hash linked list memtable representation
* Such memtable contains a fix-sized array of buckets, where
* each bucket points to a sorted singly-linked
* list (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.
*/
public class HashLinkedListMemTableConfig extends MemTableConfig {
public static final long DEFAULT_BUCKET_COUNT = 50000;
public HashLinkedListMemTableConfig() {
bucketCount_ = DEFAULT_BUCKET_COUNT;
}
/**
* Set the number of buckets in the fixed-size array used
* in the hash linked-list mem-table.
*
* @param count the number of hash buckets.
* @return the reference to the current HashLinkedListMemTableConfig.
*/
public HashLinkedListMemTableConfig setBucketCount(long count) {
bucketCount_ = count;
return this;
}
/**
* Returns the number of buckets that will be used in the memtable
* created based on this config.
*
* @return the number of buckets
*/
public long bucketCount() {
return bucketCount_;
}
@Override protected long newMemTableFactoryHandle() {
return newMemTableFactoryHandle(bucketCount_);
}
private native long newMemTableFactoryHandle(long bucketCount);
private long bucketCount_;
}