mirror of https://github.com/facebook/rocksdb.git
117 lines
3.7 KiB
Java
117 lines
3.7 KiB
Java
// Copyright (c) 2014, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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package org.rocksdb;
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/**
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* <p>A RocksEnv is an interface used by the rocksdb implementation to access
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* operating system functionality like the filesystem etc.</p>
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*
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* <p>All Env implementations are safe for concurrent access from
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* multiple threads without any external synchronization.</p>
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*/
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public class RocksEnv extends RocksObject {
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public static final int FLUSH_POOL = 0;
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public static final int COMPACTION_POOL = 1;
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static {
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default_env_ = new RocksEnv(getDefaultEnvInternal());
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}
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private static native long getDefaultEnvInternal();
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/**
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* <p>Returns the default environment suitable for the current operating
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* system.</p>
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*
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* <p>The result of {@code getDefault()} is a singleton whose ownership
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* belongs to rocksdb c++. As a result, the returned RocksEnv will not
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* have the ownership of its c++ resource, and calling its dispose()
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* will be no-op.</p>
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*
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* @return the default {@link org.rocksdb.RocksEnv} instance.
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*/
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public static RocksEnv getDefault() {
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return default_env_;
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}
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/**
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* <p>Sets the number of background worker threads of the flush pool
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* for this environment.</p>
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* <p>Default number: 1</p>
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*
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* @param num the number of threads
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*
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* @return current {@link org.rocksdb.RocksEnv} instance.
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*/
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public RocksEnv setBackgroundThreads(int num) {
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return setBackgroundThreads(num, FLUSH_POOL);
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}
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/**
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* <p>Sets the number of background worker threads of the specified thread
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* pool for this environment.</p>
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*
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* @param num the number of threads
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* @param poolID the id to specified a thread pool. Should be either
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* FLUSH_POOL or COMPACTION_POOL.
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*
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* <p>Default number: 1</p>
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* @return current {@link org.rocksdb.RocksEnv} instance.
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*/
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public RocksEnv setBackgroundThreads(int num, int poolID) {
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setBackgroundThreads(nativeHandle_, num, poolID);
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return this;
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}
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private native void setBackgroundThreads(
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long handle, int num, int priority);
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/**
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* <p>Returns the length of the queue associated with the specified
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* thread pool.</p>
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*
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* @param poolID the id to specified a thread pool. Should be either
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* FLUSH_POOL or COMPACTION_POOL.
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*
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* @return the thread pool queue length.
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*/
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public int getThreadPoolQueueLen(int poolID) {
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return getThreadPoolQueueLen(nativeHandle_, poolID);
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}
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private native int getThreadPoolQueueLen(long handle, int poolID);
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/**
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* <p>Package-private constructor that uses the specified native handle
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* to construct a RocksEnv.</p>
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*
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* <p>Note that the ownership of the input handle
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* belongs to the caller, and the newly created RocksEnv will not take
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* the ownership of the input handle. As a result, calling
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* {@code dispose()} of the created RocksEnv will be no-op.</p>
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*/
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RocksEnv(long handle) {
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super();
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nativeHandle_ = handle;
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disOwnNativeHandle();
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}
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/**
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* The helper function of {@link #dispose()} which all subclasses of
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* {@link RocksObject} must implement to release their associated C++
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* resource.
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*/
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@Override protected void disposeInternal() {
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disposeInternal(nativeHandle_);
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}
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private native void disposeInternal(long handle);
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/**
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* <p>The static default RocksEnv. The ownership of its native handle
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* belongs to rocksdb c++ and is not able to be released on the Java
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* side.</p>
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*/
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static RocksEnv default_env_;
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}
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