Package org.apache.jackrabbit.oak.segment

Class CheckpointCompactor

java.lang.Object

org.apache.jackrabbit.oak.segment.CheckpointCompactor

public class CheckpointCompactor
extends Object

This compactor implementation is aware of the checkpoints in the repository. It uses this information to further optimise the compaction result by

• Rebasing the checkpoints and subsequently the root on top of each other in chronological order. This results minimises the deltas that need to be processed and stored.
• Caching the compacted checkpoints and root states for deduplication should the same checkpoint or root state occur again in a later compaction retry cycle.

Constructor Summary

Constructors

Constructor	Description
CheckpointCompactor(@NotNull org.apache.jackrabbit.oak.spi.gc.GCMonitor gcListener, @NotNull SegmentReader reader, @NotNull SegmentWriter writer, @Nullable org.apache.jackrabbit.oak.spi.blob.BlobStore blobStore, @NotNull GCNodeWriteMonitor compactionMonitor)	Create a new instance based on the passed arguments.

Method Summary

Modifier and Type	Method	Description
@Nullable SegmentNodeState	compact(@NotNull org.apache.jackrabbit.oak.spi.state.NodeState base, @NotNull org.apache.jackrabbit.oak.spi.state.NodeState uncompacted, @NotNull org.apache.jackrabbit.oak.spi.state.NodeState onto, Canceller canceller)	Compact uncompacted on top of an optional base.

Methods inherited from class java.lang.Object

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

Constructor Detail

CheckpointCompactor

public CheckpointCompactor(@NotNull
                           @NotNull org.apache.jackrabbit.oak.spi.gc.GCMonitor gcListener,
                           @NotNull
                           @NotNull SegmentReader reader,
                           @NotNull
                           @NotNull SegmentWriter writer,
                           @Nullable
                           @Nullable org.apache.jackrabbit.oak.spi.blob.BlobStore blobStore,
                           @NotNull
                           @NotNull GCNodeWriteMonitor compactionMonitor)

Create a new instance based on the passed arguments.

Parameters:

reader - segment reader used to read from the segments

writer - segment writer used to serialise to segments

blobStore - the blob store or null if none

compactionMonitor - notification call back for each compacted nodes, properties, and binaries

Method Detail

compact

@Nullable
public @Nullable SegmentNodeState compact(@NotNull
                                          @NotNull org.apache.jackrabbit.oak.spi.state.NodeState base,
                                          @NotNull
                                          @NotNull org.apache.jackrabbit.oak.spi.state.NodeState uncompacted,
                                          @NotNull
                                          @NotNull org.apache.jackrabbit.oak.spi.state.NodeState onto,
                                          Canceller canceller)
                                   throws IOException

Compact uncompacted on top of an optional base.

Parameters:

base - the base state to compact against

uncompacted - the uncompacted state to compact

onto - the state onto which to compact the change between base and uncompacted

Returns:

compacted clone of uncompacted or null if cancelled.

Throws:

IOException