org.rocksdb.ClockCache Maven / Gradle / Ivy
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
package org.rocksdb;
/**
* Similar to {@link LRUCache}, but based on the CLOCK algorithm with
* better concurrent performance in some cases
*
* @deprecated The old Clock Cache implementation had an unresolved bug and
* has been removed. The new HyperClockCache requires an additional
* configuration parameter that is not provided by this API. This function
* simply returns a new LRUCache for functional compatibility.
*/
public class ClockCache extends Cache {
/**
* Create a new cache with a fixed size capacity.
*
* @deprecated The old Clock Cache implementation had an unresolved bug and has been removed.
*
* @param capacity The fixed size capacity of the cache
*/
public ClockCache(final long capacity) {
super(newClockCache(capacity, -1, false));
}
/**
* Create a new cache with a fixed size capacity. The cache is sharded
* to 2^numShardBits shards, by hash of the key. The total capacity
* is divided and evenly assigned to each shard.
* numShardBits = -1 means it is automatically determined: every shard
* will be at least 512KB and number of shard bits will not exceed 6.
*
* @deprecated The old Clock Cache implementation had an unresolved bug and has been removed.
*
* @param capacity The fixed size capacity of the cache
* @param numShardBits The cache is sharded to 2^numShardBits shards,
* by hash of the key
*/
public ClockCache(final long capacity, final int numShardBits) {
super(newClockCache(capacity, numShardBits, false));
}
/**
* Create a new cache with a fixed size capacity. The cache is sharded
* to 2^numShardBits shards, by hash of the key. The total capacity
* is divided and evenly assigned to each shard. If strictCapacityLimit
* is set, insert to the cache will fail when cache is full.
* numShardBits = -1 means it is automatically determined: every shard
* will be at least 512KB and number of shard bits will not exceed 6.
*
* @deprecated The old Clock Cache implementation had an unresolved bug and has been removed.
*
* @param capacity The fixed size capacity of the cache
* @param numShardBits The cache is sharded to 2^numShardBits shards,
* by hash of the key
* @param strictCapacityLimit insert to the cache will fail when cache is full
*/
public ClockCache(final long capacity, final int numShardBits,
final boolean strictCapacityLimit) {
super(newClockCache(capacity, numShardBits, strictCapacityLimit));
}
private static native long newClockCache(
final long capacity, final int numShardBits, final boolean strictCapacityLimit);
@Override
protected final void disposeInternal(final long handle) {
disposeInternalJni(handle);
}
private static native void disposeInternalJni(final long handle);
}