org.rocksdb.Env 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;
/**
* Base class for all Env implementations in RocksDB.
*/
public abstract class Env extends RocksObject {
public static final int FLUSH_POOL = 0;
public static final int COMPACTION_POOL = 1;
/**
* Returns the default environment suitable for the current operating
* system.
*
* The result of {@code getDefault()} is a singleton whose ownership
* belongs to rocksdb c++. As a result, the returned RocksEnv will not
* have the ownership of its c++ resource, and calling its dispose()
* will be no-op.
*
* @return the default {@link org.rocksdb.RocksEnv} instance.
*/
public static Env getDefault() {
return default_env_;
}
/**
* Sets the number of background worker threads of the flush pool
* for this environment.
* Default number: 1
*
* @param num the number of threads
*
* @return current {@link RocksEnv} instance.
*/
public Env setBackgroundThreads(final int num) {
return setBackgroundThreads(num, FLUSH_POOL);
}
/**
* Sets the number of background worker threads of the specified thread
* pool for this environment.
*
* @param num the number of threads
* @param poolID the id to specified a thread pool. Should be either
* FLUSH_POOL or COMPACTION_POOL.
*
* Default number: 1
* @return current {@link RocksEnv} instance.
*/
public Env setBackgroundThreads(final int num, final int poolID) {
setBackgroundThreads(nativeHandle_, num, poolID);
return this;
}
/**
* Returns the length of the queue associated with the specified
* thread pool.
*
* @param poolID the id to specified a thread pool. Should be either
* FLUSH_POOL or COMPACTION_POOL.
*
* @return the thread pool queue length.
*/
public int getThreadPoolQueueLen(final int poolID) {
return getThreadPoolQueueLen(nativeHandle_, poolID);
}
protected Env(final long nativeHandle) {
super(nativeHandle);
}
static {
default_env_ = new RocksEnv(getDefaultEnvInternal());
}
/**
* The static default Env. The ownership of its native handle
* belongs to rocksdb c++ and is not able to be released on the Java
* side.
*/
static Env default_env_;
private static native long getDefaultEnvInternal();
private native void setBackgroundThreads(
long handle, int num, int priority);
private native int getThreadPoolQueueLen(long handle, int poolID);
}