org.apache.jackrabbit.oak.plugins.segment

Class SegmentGraph

java.lang.Object

org.apache.jackrabbit.oak.plugins.segment.SegmentGraph

public final class SegmentGraph
extends Object

Utility graph for parsing a segment graph.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SegmentGraph.Graph<T> A simple graph representation for a graph with node of type T.
static interface	SegmentGraph.SegmentGraphVisitor Visitor for receiving call backs while traversing the segment graph.

Method Summary

Methods

Modifier and Type	Method and Description
static com.google.common.base.Predicate<UUID>	createRegExpFilter(String pattern, SegmentTracker tracker) Create a regular expression based inclusion filter for segment.
static SegmentGraph.Graph<String>	parseGCGraph(FileStore.ReadOnlyStore fileStore) Parse the gc generation graph of a file store.
static SegmentGraph.Graph<UUID>	parseHeadGraph(RecordId root) Parser the head graph.
static SegmentGraph.Graph<UUID>	parseSegmentGraph(FileStore.ReadOnlyStore fileStore, com.google.common.base.Predicate<UUID> filter) Parse the segment graph of a file store.
static <T> SegmentGraph.Graph<T>	parseSegmentGraph(FileStore.ReadOnlyStore fileStore, Set<UUID> roots, com.google.common.base.Predicate<UUID> filter, com.google.common.base.Function<UUID,T> map) Parse the segment graph of a file store starting with a given set of root segments.
static void	writeGCGraph(FileStore.ReadOnlyStore fileStore, OutputStream out) Write the gc generation graph of a file store to a stream.
static void	writeSegmentGraph(FileStore.ReadOnlyStore fileStore, OutputStream out, Date epoch, String pattern) Write the segment graph of a file store to a stream.

Methods inherited from class java.lang.Object

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

Method Detail

writeSegmentGraph

public static void writeSegmentGraph(@Nonnull
                     FileStore.ReadOnlyStore fileStore,
                     @Nonnull
                     OutputStream out,
                     @Nonnull
                     Date epoch,
                     @CheckForNull
                     String pattern)
                              throws Exception

Write the segment graph of a file store to a stream.

The graph is written in the Guess GDF format, which is easily imported into Gephi. As GDF only supports integers but the segment time stamps are encoded as long the epoch argument is used as a negative offset translating all timestamps into a valid int range.

Parameters:

fileStore - file store to graph

out - stream to write the graph to

epoch - epoch (in milliseconds)

pattern - regular expression specifying inclusion of nodes or null for all nodes.

Throws:

Exception

createRegExpFilter

public static com.google.common.base.Predicate<UUID> createRegExpFilter(@Nonnull
                                                        String pattern,
                                                        @Nonnull
                                                        SegmentTracker tracker)

Create a regular expression based inclusion filter for segment.

Parameters:

pattern - regular expression specifying inclusion of nodes.

tracker - the segment tracker of the store acting upon.

Returns:

parseSegmentGraph

@Nonnull
public static SegmentGraph.Graph<UUID> parseSegmentGraph(@Nonnull
                                                 FileStore.ReadOnlyStore fileStore,
                                                 @Nonnull
                                                 com.google.common.base.Predicate<UUID> filter)
                                                  throws IOException

Parse the segment graph of a file store.

Parameters:

fileStore - file store to parse

filter - inclusion criteria for vertices and edges. An edge is only included if both its source and target vertex are included.

Returns:

the segment graph rooted as the segment containing the head node state of fileStore.

Throws:

IOException

writeGCGraph

public static void writeGCGraph(@Nonnull
                FileStore.ReadOnlyStore fileStore,
                @Nonnull
                OutputStream out)
                         throws Exception

Write the gc generation graph of a file store to a stream.

The graph is written in the Guess GDF format, which is easily imported into Gephi.

Parameters:

fileStore - file store to graph

out - stream to write the graph to

Throws:

Exception

parseGCGraph

@Nonnull
public static SegmentGraph.Graph<String> parseGCGraph(@Nonnull
                                              FileStore.ReadOnlyStore fileStore)
                                               throws IOException

Parse the gc generation graph of a file store.

Parameters:

fileStore - file store to parse

Returns:

the gc generation graph rooted ad the segment containing the head node state of fileStore.

Throws:

IOException

parseSegmentGraph

@Nonnull
public static <T> SegmentGraph.Graph<T> parseSegmentGraph(@Nonnull
                                                  FileStore.ReadOnlyStore fileStore,
                                                  @Nonnull
                                                  Set<UUID> roots,
                                                  @Nonnull
                                                  com.google.common.base.Predicate<UUID> filter,
                                                  @Nonnull
                                                  com.google.common.base.Function<UUID,T> map)
                                               throws IOException

Parse the segment graph of a file store starting with a given set of root segments. The full segment graph is mapped through the passed map to the graph returned by this function.

Parameters:

fileStore - file store to parse

roots - the initial set of segments

map - map defining an homomorphism from the segment graph into the returned graph

filter - inclusion criteria for vertices and edges. An edge is only included if both its source and target vertex are included.

Returns:

the segment graph of fileStore rooted at roots and mapped by map

Throws:

IOException

parseHeadGraph

@Nonnull
public static SegmentGraph.Graph<UUID> parseHeadGraph(@Nonnull
                                              RecordId root)

Parser the head graph. The head graph is the sub graph of the segment graph containing the root.

Parameters:

root -

Returns:

the head graph of root.