org.apache.jackrabbit.oak.segment

Class Compactor

java.lang.Object

org.apache.jackrabbit.oak.segment.Compactor

public class Compactor
extends Object

Instances of this class can be used to compact a node state. I.e. to create a clone of a given node state without value sharing except for binaries. Binaries that are stored in a list of bulk segments will still value share the bulk segments (but not the list records). A node can either be compacted on its own or alternatively the difference between two nodes can be compacted on top of an already compacted node.

Constructor Summary

Constructors

Constructor and Description
Compactor(SegmentReader reader, SegmentWriter writer, BlobStore blobStore, Supplier<Boolean> cancel, GCNodeWriteMonitor compactionMonitor) Create a new instance based on the passed arguments.

Method Summary

Modifier and Type	Method and Description
SegmentNodeState	compact(NodeState state) Compact a given state
SegmentNodeState	compact(NodeState before, NodeState after, NodeState onto) compact the differences between after and before on top of ont.

Methods inherited from class java.lang.Object

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

Constructor Detail

Compactor

public Compactor(@Nonnull
                 SegmentReader reader,
                 @Nonnull
                 SegmentWriter writer,
                 @Nullable
                 BlobStore blobStore,
                 @Nonnull
                 Supplier<Boolean> cancel,
                 @Nonnull
                 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

cancel - a flag that can be used to cancel the compaction process

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

Method Detail

compact

@CheckForNull
public SegmentNodeState compact(@Nonnull
                                               NodeState state)
                                        throws IOException

Compact a given state

Parameters:

state - the node state to compact

Returns:

the compacted node state or null if cancelled.

Throws:

IOException

compact

@CheckForNull
public SegmentNodeState compact(@Nonnull
                                               NodeState before,
                                               @Nonnull
                                               NodeState after,
                                               @Nonnull
                                               NodeState onto)
                                        throws IOException

compact the differences between after and before on top of ont.

Parameters:

before - the node state to diff against from after

after - the node state diffed against before

onto - the node state compacted onto

Returns:

the compacted node state or null if cancelled.

Throws:

IOException