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(@NotNull SegmentReader reader, @NotNull SegmentWriter writer, @Nullable BlobStore blobStore, @NotNull GCNodeWriteMonitor compactionMonitor) Create a new instance based on the passed arguments.

Method Summary

Modifier and Type	Method and Description
@Nullable SegmentNodeState	compact(@NotNull NodeState state, Canceller canceller) Compact a given state
@Nullable SegmentNodeState	compact(@NotNull NodeState before, @NotNull NodeState after, @NotNull NodeState onto, Canceller canceller) 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(@NotNull
                 @NotNull SegmentReader reader,
                 @NotNull
                 @NotNull SegmentWriter writer,
                 @Nullable
                 @Nullable 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 NodeState state,
                                                    Canceller canceller)
                                             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

@Nullable
public @Nullable SegmentNodeState compact(@NotNull
                                                    @NotNull NodeState before,
                                                    @NotNull
                                                    @NotNull NodeState after,
                                                    @NotNull
                                                    @NotNull NodeState onto,
                                                    Canceller canceller)
                                             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