WindowCacheConfig.java
/*
* Copyright (C) 2009, Google Inc.
* and other copyright owners as documented in the project's IP log.
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* This program and the accompanying materials are made available
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package org.eclipse.jgit.storage.file;
import org.eclipse.jgit.internal.storage.file.WindowCache;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.storage.pack.PackConfig;
/**
* Configuration parameters for JVM-wide buffer cache used by JGit.
*/
public class WindowCacheConfig {
/** 1024 (number of bytes in one kibibyte/kilobyte) */
public static final int KB = 1024;
/** 1024 {@link #KB} (number of bytes in one mebibyte/megabyte) */
public static final int MB = 1024 * KB;
private int packedGitOpenFiles;
private long packedGitLimit;
private int packedGitWindowSize;
private boolean packedGitMMAP;
private int deltaBaseCacheLimit;
private int streamFileThreshold;
/**
* Create a default configuration.
*/
public WindowCacheConfig() {
packedGitOpenFiles = 128;
packedGitLimit = 10 * MB;
packedGitWindowSize = 8 * KB;
packedGitMMAP = false;
deltaBaseCacheLimit = 10 * MB;
streamFileThreshold = PackConfig.DEFAULT_BIG_FILE_THRESHOLD;
}
/**
* Get maximum number of streams to open at a time.
*
* @return maximum number of streams to open at a time. Open packs count
* against the process limits. <b>Default is 128.</b>
*/
public int getPackedGitOpenFiles() {
return packedGitOpenFiles;
}
/**
* Set maximum number of streams to open at a time.
*
* @param fdLimit
* maximum number of streams to open at a time. Open packs count
* against the process limits
*/
public void setPackedGitOpenFiles(int fdLimit) {
packedGitOpenFiles = fdLimit;
}
/**
* Get maximum number bytes of heap memory to dedicate to caching pack file
* data.
*
* @return maximum number bytes of heap memory to dedicate to caching pack
* file data. <b>Default is 10 MB.</b>
*/
public long getPackedGitLimit() {
return packedGitLimit;
}
/**
* Set maximum number bytes of heap memory to dedicate to caching pack file
* data.
*
* @param newLimit
* maximum number bytes of heap memory to dedicate to caching
* pack file data.
*/
public void setPackedGitLimit(long newLimit) {
packedGitLimit = newLimit;
}
/**
* Get size in bytes of a single window mapped or read in from the pack
* file.
*
* @return size in bytes of a single window mapped or read in from the pack
* file. <b>Default is 8 KB.</b>
*/
public int getPackedGitWindowSize() {
return packedGitWindowSize;
}
/**
* Set size in bytes of a single window read in from the pack file.
*
* @param newSize
* size in bytes of a single window read in from the pack file.
*/
public void setPackedGitWindowSize(int newSize) {
packedGitWindowSize = newSize;
}
/**
* Whether to use Java NIO virtual memory mapping for windows
*
* @return {@code true} enables use of Java NIO virtual memory mapping for
* windows; false reads entire window into a byte[] with standard
* read calls. <b>Default false.</b>
*/
public boolean isPackedGitMMAP() {
return packedGitMMAP;
}
/**
* Set whether to enable use of Java NIO virtual memory mapping for windows
*
* @param usemmap
* {@code true} enables use of Java NIO virtual memory mapping
* for windows; false reads entire window into a byte[] with
* standard read calls.
*/
public void setPackedGitMMAP(boolean usemmap) {
packedGitMMAP = usemmap;
}
/**
* Get maximum number of bytes to cache in delta base cache for inflated,
* recently accessed objects, without delta chains.
*
* @return maximum number of bytes to cache in delta base cache for
* inflated, recently accessed objects, without delta chains.
* <b>Default 10 MB.</b>
*/
public int getDeltaBaseCacheLimit() {
return deltaBaseCacheLimit;
}
/**
* Set maximum number of bytes to cache in delta base cache for inflated,
* recently accessed objects, without delta chains.
*
* @param newLimit
* maximum number of bytes to cache in delta base cache for
* inflated, recently accessed objects, without delta chains.
*/
public void setDeltaBaseCacheLimit(int newLimit) {
deltaBaseCacheLimit = newLimit;
}
/**
* Get the size threshold beyond which objects must be streamed.
*
* @return the size threshold beyond which objects must be streamed.
*/
public int getStreamFileThreshold() {
return streamFileThreshold;
}
/**
* Set new byte limit for objects that must be streamed.
*
* @param newLimit
* new byte limit for objects that must be streamed. Objects
* smaller than this size can be obtained as a contiguous byte
* array, while objects bigger than this size require using an
* {@link org.eclipse.jgit.lib.ObjectStream}.
*/
public void setStreamFileThreshold(int newLimit) {
streamFileThreshold = newLimit;
}
/**
* Update properties by setting fields from the configuration.
* <p>
* If a property is not defined in the configuration, then it is left
* unmodified.
*
* @param rc
* configuration to read properties from.
* @return {@code this}.
* @since 3.0
*/
public WindowCacheConfig fromConfig(Config rc) {
setPackedGitOpenFiles(rc.getInt(
"core", null, "packedgitopenfiles", getPackedGitOpenFiles())); //$NON-NLS-1$ //$NON-NLS-2$
setPackedGitLimit(rc.getLong(
"core", null, "packedgitlimit", getPackedGitLimit())); //$NON-NLS-1$ //$NON-NLS-2$
setPackedGitWindowSize(rc.getInt(
"core", null, "packedgitwindowsize", getPackedGitWindowSize())); //$NON-NLS-1$ //$NON-NLS-2$
setPackedGitMMAP(rc.getBoolean(
"core", null, "packedgitmmap", isPackedGitMMAP())); //$NON-NLS-1$ //$NON-NLS-2$
setDeltaBaseCacheLimit(rc.getInt(
"core", null, "deltabasecachelimit", getDeltaBaseCacheLimit())); //$NON-NLS-1$ //$NON-NLS-2$
long maxMem = Runtime.getRuntime().maxMemory();
long sft = rc.getLong(
"core", null, "streamfilethreshold", getStreamFileThreshold()); //$NON-NLS-1$ //$NON-NLS-2$
sft = Math.min(sft, maxMem / 4); // don't use more than 1/4 of the heap
sft = Math.min(sft, Integer.MAX_VALUE); // cannot exceed array length
setStreamFileThreshold((int) sft);
return this;
}
/**
* Install this configuration as the live settings.
* <p>
* The new configuration is applied immediately. If the new limits are
* smaller than what is currently cached, older entries will be purged
* as soon as possible to allow the cache to meet the new limit.
*
* @since 3.0
*/
@SuppressWarnings("deprecation")
public void install() {
WindowCache.reconfigure(this);
}
}