org.eclipse.jgit.internal.storage.dfs

Class DfsGarbageCollector

java.lang.Object

org.eclipse.jgit.internal.storage.dfs.DfsGarbageCollector

public class DfsGarbageCollector
extends Object

Repack and garbage collect a repository.

Constructor Summary

Constructors

Constructor and Description
DfsGarbageCollector(DfsRepository repository) Initialize a garbage collector.

Method Summary

Methods

Modifier and Type	Method and Description
long	getCoalesceGarbageLimit()
List<DfsPackDescription>	getNewPacks()
List<PackWriter.Statistics>	getNewPackStatistics()
PackConfig	getPackConfig()
List<DfsPackDescription>	getSourcePacks()
boolean	pack(ProgressMonitor pm) Create a single new pack file containing all of the live objects.
DfsGarbageCollector	setCoalesceGarbageLimit(long limit) Set the byte size limit for garbage packs to be repacked.
DfsGarbageCollector	setPackConfig(PackConfig newConfig)

Methods inherited from class java.lang.Object

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

Constructor Detail

DfsGarbageCollector

public DfsGarbageCollector(DfsRepository repository)

Initialize a garbage collector.

Parameters:

repository - repository objects to be packed will be read from.

Method Detail

getPackConfig

public PackConfig getPackConfig()

Returns:

configuration used to generate the new pack file.

setPackConfig

public DfsGarbageCollector setPackConfig(PackConfig newConfig)

Parameters:

newConfig - the new configuration to use when creating the pack file.

Returns:

this

getCoalesceGarbageLimit

public long getCoalesceGarbageLimit()

Returns:

garbage packs smaller than this size will be repacked.

setCoalesceGarbageLimit

public DfsGarbageCollector setCoalesceGarbageLimit(long limit)

Set the byte size limit for garbage packs to be repacked.

Any UNREACHABLE_GARBAGE pack smaller than this limit will be repacked at the end of the run. This allows the garbage collector to coalesce unreachable objects into a single file.

If an UNREACHABLE_GARBAGE pack is already larger than this limit it will be left alone by the garbage collector. This avoids unnecessary disk IO reading and copying the objects.

If limit is set to 0 the UNREACHABLE_GARBAGE coalesce is disabled.
If limit is set to Long.MAX_VALUE, everything is coalesced.

Keeping unreachable garbage prevents race conditions with repository changes that may suddenly need an object whose only copy was stored in the UNREACHABLE_GARBAGE pack.

Parameters:

limit - size in bytes.

Returns:

this

pack

public boolean pack(ProgressMonitor pm)
             throws IOException

Create a single new pack file containing all of the live objects.

This method safely decides which packs can be expired after the new pack is created by validating the references have not been modified in an incompatible way.

Parameters:

pm - progress monitor to receive updates on as packing may take a while, depending on the size of the repository.

Returns:

true if the repack was successful without race conditions. False if a race condition was detected and the repack should be run again later.

Throws:

IOException - a new pack cannot be created.

getSourcePacks

public List<DfsPackDescription> getSourcePacks()

Returns:

all of the source packs that fed into this compaction.

getNewPacks

public List<DfsPackDescription> getNewPacks()

Returns:

new packs created by this compaction.

getNewPackStatistics

public List<PackWriter.Statistics> getNewPackStatistics()

Returns:

statistics corresponding to the getNewPacks().