org.eclipse.jgit.storage.dfs
Class DfsPackCompactor

java.lang.Object
  org.eclipse.jgit.storage.dfs.DfsPackCompactor

public class DfsPackCompactor
extends Object

Combine several pack files into one pack.

The compactor combines several pack files together by including all objects contained in each pack file into the same output pack. If an object appears multiple times, it is only included once in the result. Because the new pack is constructed by enumerating the indexes of the source packs, it is quicker than doing a full repack of the repository, however the result is not nearly as space efficient as new delta compression is disabled.

This method is suitable for quickly combining several packs together after receiving a number of small fetch or push operations into a repository, allowing the system to maintain reasonable read performance without expending a lot of time repacking the entire repository.

Constructor Summary

DfsPackCompactor(DfsRepository repository)
Initialize a pack compactor.

Method Summary

DfsPackCompactor	add(DfsPackFile pack) Add a pack to be compacted.
DfsPackCompactor	autoAdd() Automatically select packs to be included, and add them.
void	compact(ProgressMonitor pm) Compact the pack files together.
List<DfsPackDescription>	getNewPacks()
List<PackWriter.Statistics>	getNewPackStatistics()
List<DfsPackDescription>	getSourcePacks()

Methods inherited from class java.lang.Object

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

Constructor Detail

DfsPackCompactor

public DfsPackCompactor(DfsRepository repository)

Initialize a pack compactor.

Parameters:

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

Method Detail

add

public DfsPackCompactor add(DfsPackFile pack)

Add a pack to be compacted.

All of the objects in this pack will be copied into the resulting pack. The resulting pack will order objects according to the source pack's own description ordering (which is based on creation date), and then by the order the objects appear in the source pack.

Parameters:

pack - a pack to combine into the resulting pack.

Returns:

this

autoAdd

public DfsPackCompactor autoAdd()
                         throws IOException

Automatically select packs to be included, and add them.

Packs are selected based on size, smaller packs get included while bigger ones are omitted.

Returns:

this

Throws:

IOException - existing packs cannot be read.

compact

public void compact(ProgressMonitor pm)
             throws IOException

Compact the pack files together.

Parameters:

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

Throws:

IOException - the packs cannot be compacted.

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().