Package org.eclipse.jgit.internal.storage.reftable

Class ReftableCompactor

java.lang.Object

org.eclipse.jgit.internal.storage.reftable.ReftableCompactor

public class ReftableCompactor
extends Object

Merges reftables and compacts them into a single output.

For a partial compaction callers should setIncludeDeletes(boolean) to true to ensure the new reftable continues to use a delete marker to shadow any lower reftable that may have the reference present.

By default all log entries within the range defined by setReflogExpireMinUpdateIndex(long) and setReflogExpireMaxUpdateIndex(long) are copied, even if no references in the output file match the log records. Callers may truncate the log to a more recent time horizon with setReflogExpireOldestReflogTimeMillis(long), or disable the log altogether with setOldestReflogTimeMillis(Long.MAX_VALUE).

Constructor Summary

Constructors

Constructor	Description
ReftableCompactor(OutputStream out)	Creates a new compactor.

Method Summary

Modifier and Type	Method	Description
void	addAll(List<ReftableReader> readers)	Add all of the tables, in the specified order.
void	compact()	Write a compaction to out.
ReftableWriter.Stats	getStats()	Get statistics of the last written reftable.
ReftableCompactor	setConfig(ReftableConfig cfg)	Set configuration for the reftable.
ReftableCompactor	setIncludeDeletes(boolean deletes)	Whether to include deletions in the output, which may be necessary for partial compaction.
ReftableCompactor	setReflogExpireMaxUpdateIndex(long max)	Set the maximum update index for log entries that appear in the compacted reftable.
ReftableCompactor	setReflogExpireMinUpdateIndex(long min)	Set the minimum update index for log entries that appear in the compacted reftable.
ReftableCompactor	setReflogExpireOldestReflogTimeMillis(long timeMillis)	Set oldest reflog time to preserve.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReftableCompactor

public ReftableCompactor(OutputStream out)

Creates a new compactor.

Parameters:

out - stream to write the compacted tables to. Caller is responsible for closing out.

Method Detail

setConfig

public ReftableCompactor setConfig(ReftableConfig cfg)

Set configuration for the reftable.

Parameters:

cfg - configuration for the reftable.

Returns:

this

setIncludeDeletes

public ReftableCompactor setIncludeDeletes(boolean deletes)

Whether to include deletions in the output, which may be necessary for partial compaction.

Parameters:

deletes - true to include deletions in the output, which may be necessary for partial compaction.

Returns:

this

setReflogExpireMinUpdateIndex

public ReftableCompactor setReflogExpireMinUpdateIndex(long min)

Set the minimum update index for log entries that appear in the compacted reftable.

Parameters:

min - the minimum update index for log entries that appear in the compacted reftable. This should be 1 higher than the prior reftable's maxUpdateIndex if this table will be used in a stack.

Returns:

this

setReflogExpireMaxUpdateIndex

public ReftableCompactor setReflogExpireMaxUpdateIndex(long max)

Set the maximum update index for log entries that appear in the compacted reftable.

Parameters:

max - the maximum update index for log entries that appear in the compacted reftable. This should be at least 1 higher than the prior reftable's maxUpdateIndex if this table will be used in a stack.

Returns:

this

setReflogExpireOldestReflogTimeMillis

public ReftableCompactor setReflogExpireOldestReflogTimeMillis(long timeMillis)

Set oldest reflog time to preserve.

Parameters:

timeMillis - oldest log time to preserve. Entries whose timestamps are >= timeMillis will be copied into the output file. Log entries that predate timeMillis will be discarded. Specified in Java standard milliseconds since the epoch.

Returns:

this

addAll

public void addAll(List<ReftableReader> readers)
            throws IOException

Add all of the tables, in the specified order.

Parameters:

readers - tables to compact. Tables should be ordered oldest first/most recent last so that the more recent tables can shadow the older results. Caller is responsible for closing the readers.

Throws:

IOException - update indexes of a reader cannot be accessed.

compact

public void compact()
             throws IOException

Write a compaction to out.

Throws:

IOException - if tables cannot be read, or cannot be written.

getStats

public ReftableWriter.Stats getStats()

Get statistics of the last written reftable.

Returns:

statistics of the last written reftable.