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RocksDB fat jar that contains .so files for linux64, jnilib files
for Mac OSX, and a .dll for Windows x64. It contains the Yamcs merge operator for the Parameter Archive
// Copyright (c) Meta Platforms, Inc. and affiliates.
//
// 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;
/**
* HyperClockCache - A lock-free Cache alternative for RocksDB block cache
* that offers much improved CPU efficiency vs. LRUCache under high parallel
* load or high contention, with some caveats:
*
* -
* Not a general Cache implementation: can only be used for
* BlockBasedTableOptions::block_cache, which RocksDB uses in a way that is
* compatible with HyperClockCache.
*
* -
* Requires an extra tuning parameter: see estimated_entry_charge below.
* Similarly, substantially changing the capacity with SetCapacity could
* harm efficiency. -> EXPERIMENTAL: the tuning parameter can be set to 0
* to find the appropriate balance automatically.
*
* -
* Cache priorities are less aggressively enforced, which could cause
* cache dilution from long range scans (unless they use fill_cache=false).
*
* -
* Can be worse for small caches, because if almost all of a cache shard is
* pinned (more likely with non-partitioned filters), then CLOCK eviction
* becomes very CPU intensive.
*
*
*/
@Experimental("HyperClockCache is still experimental and this API may change in future.")
public class HyperClockCache extends Cache {
/**
*
* @param capacity The fixed size capacity of the cache
* @param estimatedEntryCharge EXPERIMENTAL: the field can be set to 0 to size the table
* dynamically and automatically. See C++ Api for more info.
* @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 HyperClockCache(final long capacity, final long estimatedEntryCharge, int numShardBits,
boolean strictCapacityLimit) {
super(newHyperClockCache(capacity, estimatedEntryCharge, numShardBits, strictCapacityLimit));
}
@Override
protected void disposeInternal(long handle) {
disposeInternalJni(handle);
}
private static native void disposeInternalJni(long handle);
private static native long newHyperClockCache(final long capacity,
final long estimatedEntryCharge, int numShardBits, boolean strictCapacityLimit);
}