org.eclipse.jgit.storage.file

Class WindowCacheConfig

java.lang.Object

org.eclipse.jgit.storage.file.WindowCacheConfig

public class WindowCacheConfig
extends Object

Configuration parameters for JVM-wide buffer cache used by JGit.

Field Summary

Fields

Modifier and Type	Field and Description
static int	KB 1024 (number of bytes in one kibibyte/kilobyte)
static int	MB 1024 KB (number of bytes in one mebibyte/megabyte)

Constructor Summary

Constructors

Constructor and Description
WindowCacheConfig() Create a default configuration.

Method Summary

Modifier and Type	Method and Description
WindowCacheConfig	fromConfig(Config rc) Update properties by setting fields from the configuration.
int	getDeltaBaseCacheLimit() Get maximum number of bytes to cache in delta base cache for inflated, recently accessed objects, without delta chains.
boolean	getExposeStatsViaJmx() Tell whether the statistics JMX bean should be automatically registered.
long	getPackedGitLimit() Get maximum number bytes of heap memory to dedicate to caching pack file data.
int	getPackedGitOpenFiles() Get maximum number of streams to open at a time.
int	getPackedGitWindowSize() Get size in bytes of a single window mapped or read in from the pack file.
int	getStreamFileThreshold() Get the size threshold beyond which objects must be streamed.
void	install() Install this configuration as the live settings.
boolean	isPackedGitMMAP() Whether to use Java NIO virtual memory mapping for windows
boolean	isPackedGitUseStrongRefs() Get whether the window cache should use strong references or SoftReferences
void	setDeltaBaseCacheLimit(int newLimit) Set maximum number of bytes to cache in delta base cache for inflated, recently accessed objects, without delta chains.
void	setExposeStatsViaJmx(boolean expose) Defines whether the statistics JMX MBean should be automatically set up.
void	setPackedGitLimit(long newLimit) Set maximum number bytes of heap memory to dedicate to caching pack file data.
void	setPackedGitMMAP(boolean usemmap) Set whether to enable use of Java NIO virtual memory mapping for windows
void	setPackedGitOpenFiles(int fdLimit) Set maximum number of streams to open at a time.
void	setPackedGitUseStrongRefs(boolean useStrongRefs) Set if the cache should use strong refs or soft refs
void	setPackedGitWindowSize(int newSize) Set size in bytes of a single window read in from the pack file.
void	setStreamFileThreshold(int newLimit) Set new byte limit for objects that must be streamed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

KB

public static final int KB

1024 (number of bytes in one kibibyte/kilobyte)

See Also:

Constant Field Values

MB

public static final int MB

1024 KB (number of bytes in one mebibyte/megabyte)

See Also:

Constant Field Values

Constructor Detail

WindowCacheConfig

public WindowCacheConfig()

Create a default configuration.

Method Detail

getPackedGitOpenFiles

public int getPackedGitOpenFiles()

Get maximum number of streams to open at a time.

Returns:

maximum number of streams to open at a time. Open packs count against the process limits. Default is 128.

setPackedGitOpenFiles

public void setPackedGitOpenFiles(int fdLimit)

Set maximum number of streams to open at a time.

Parameters:

fdLimit - maximum number of streams to open at a time. Open packs count against the process limits

getPackedGitLimit

public long getPackedGitLimit()

Get maximum number bytes of heap memory to dedicate to caching pack file data.

Returns:

maximum number bytes of heap memory to dedicate to caching pack file data. Default is 10 MB.

setPackedGitLimit

public void setPackedGitLimit(long newLimit)

Set maximum number bytes of heap memory to dedicate to caching pack file data.

Parameters:

newLimit - maximum number bytes of heap memory to dedicate to caching pack file data.

isPackedGitUseStrongRefs

public boolean isPackedGitUseStrongRefs()

Get whether the window cache should use strong references or SoftReferences

Returns:

true if the window cache should use strong references, otherwise it will use SoftReferences

Since:

5.1.13

setPackedGitUseStrongRefs

public void setPackedGitUseStrongRefs(boolean useStrongRefs)

Set if the cache should use strong refs or soft refs

Parameters:

useStrongRefs - if @{code true} the cache strongly references cache pages otherwise it uses SoftReferences which can be evicted by the Java gc if heap is almost full

Since:

5.1.13

getPackedGitWindowSize

public int getPackedGitWindowSize()

Get size in bytes of a single window mapped or read in from the pack file.

Returns:

size in bytes of a single window mapped or read in from the pack file. Default is 8 KB.

setPackedGitWindowSize

public void setPackedGitWindowSize(int newSize)

Set size in bytes of a single window read in from the pack file.

Parameters:

newSize - size in bytes of a single window read in from the pack file.

isPackedGitMMAP

public boolean isPackedGitMMAP()

Whether to use Java NIO virtual memory mapping for windows

Returns:

true enables use of Java NIO virtual memory mapping for windows; false reads entire window into a byte[] with standard read calls. Default false.

setPackedGitMMAP

public void setPackedGitMMAP(boolean usemmap)

Set whether to enable use of Java NIO virtual memory mapping for windows

Parameters:

usemmap - true enables use of Java NIO virtual memory mapping for windows; false reads entire window into a byte[] with standard read calls.

getDeltaBaseCacheLimit

public int getDeltaBaseCacheLimit()

Get maximum number of bytes to cache in delta base cache for inflated, recently accessed objects, without delta chains.

Returns:

maximum number of bytes to cache in delta base cache for inflated, recently accessed objects, without delta chains. Default 10 MB.

setDeltaBaseCacheLimit

public void setDeltaBaseCacheLimit(int newLimit)

Set maximum number of bytes to cache in delta base cache for inflated, recently accessed objects, without delta chains.

Parameters:

newLimit - maximum number of bytes to cache in delta base cache for inflated, recently accessed objects, without delta chains.

getStreamFileThreshold

public int getStreamFileThreshold()

Get the size threshold beyond which objects must be streamed.

Returns:

the size threshold beyond which objects must be streamed.

setStreamFileThreshold

public void setStreamFileThreshold(int newLimit)

Set new byte limit for objects that must be streamed.

Parameters:

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 ObjectStream.

getExposeStatsViaJmx

public boolean getExposeStatsViaJmx()

Tell whether the statistics JMX bean should be automatically registered.

Registration of that bean via JMX is additionally subject to a boolean JGit-specific user config "jmx.WindowCacheStats". The bean will be registered only if this user config is true and getExposeStatsViaJmx() == true.

By default, this returns true unless changed via setExposeStatsViaJmx(boolean).

Returns:

whether to expose WindowCacheStats statistics via JMX upon install()

Since:

5.8

setExposeStatsViaJmx

public void setExposeStatsViaJmx(boolean expose)

Defines whether the statistics JMX MBean should be automatically set up. (By default true.) If set to false, the JMX monitoring bean is not registered.

Parameters:

expose - whether to register the JMX Bean

Since:

5.8

fromConfig

public WindowCacheConfig fromConfig(Config rc)

Update properties by setting fields from the configuration.

If a property is not defined in the configuration, then it is left unmodified.

Parameters:

rc - configuration to read properties from.

Returns:

this.

Since:

3.0

install

public void install()

Install this configuration as the live settings.

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