com.netflix.nfgraph.compressed

Class NFCompressedGraph

java.lang.Object

com.netflix.nfgraph.NFGraph

com.netflix.nfgraph.compressed.NFCompressedGraph

public class NFCompressedGraph
extends NFGraph

A read-only, memory-efficient implementation of an NFGraph. The connections for all nodes in the graph are encoded into a single byte array. The encoding for each set will be specified as either a CompactOrdinalSet or HashSetOrdinalSet. If it is more efficient, the actual encoding will be a BitSetOrdinalSet.

The offsets into the byte array where connections for each node are encoded are held in the NFCompressedGraphPointers.

Field Summary

Fields inherited from class com.netflix.nfgraph.NFGraph

graphSpec, modelHolder

Constructor Summary

Constructors

Constructor and Description
NFCompressedGraph(NFGraphSpec spec, com.netflix.nfgraph.NFGraphModelHolder modelHolder, com.netflix.nfgraph.util.ByteData data, long dataLength, com.netflix.nfgraph.compressed.NFCompressedGraphPointers pointers)

Method Summary

Modifier and Type	Method and Description
void	destroy() When using a ByteSegmentPool, this method will return all borrowed arrays back to that pool.
protected int	getConnection(int connectionModelIndex, java.lang.String nodeType, int ordinal, java.lang.String propertyName)
protected OrdinalIterator	getConnectionIterator(int connectionModelIndex, java.lang.String nodeType, int ordinal, java.lang.String propertyName)
protected OrdinalSet	getConnectionSet(int connectionModelIndex, java.lang.String nodeType, int ordinal, java.lang.String propertyName)
static NFCompressedGraph	readFrom(java.io.InputStream is)
static NFCompressedGraph	readFrom(java.io.InputStream is, com.netflix.nfgraph.util.ByteSegmentPool memoryPool) When using a ByteSegmentPool, this method will borrow arrays used to construct the NFCompressedGraph from that pool.
void	writeTo(java.io.OutputStream os)

Methods inherited from class com.netflix.nfgraph.NFGraph

getConnection, getConnection, getConnectionIterator, getConnectionIterator, getConnectionSet, getConnectionSet

Methods inherited from class java.lang.Object

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

Constructor Detail

NFCompressedGraph

public NFCompressedGraph(NFGraphSpec spec,
                         com.netflix.nfgraph.NFGraphModelHolder modelHolder,
                         com.netflix.nfgraph.util.ByteData data,
                         long dataLength,
                         com.netflix.nfgraph.compressed.NFCompressedGraphPointers pointers)

Method Detail

getConnection

protected int getConnection(int connectionModelIndex,
                            java.lang.String nodeType,
                            int ordinal,
                            java.lang.String propertyName)

Specified by:

getConnection in class NFGraph

getConnectionSet

protected OrdinalSet getConnectionSet(int connectionModelIndex,
                                      java.lang.String nodeType,
                                      int ordinal,
                                      java.lang.String propertyName)

Specified by:

getConnectionSet in class NFGraph

getConnectionIterator

protected OrdinalIterator getConnectionIterator(int connectionModelIndex,
                                                java.lang.String nodeType,
                                                int ordinal,
                                                java.lang.String propertyName)

Specified by:

getConnectionIterator in class NFGraph

writeTo

public void writeTo(java.io.OutputStream os)
             throws java.io.IOException

Throws:

java.io.IOException

readFrom

public static NFCompressedGraph readFrom(java.io.InputStream is)
                                  throws java.io.IOException

Throws:

java.io.IOException

readFrom

public static NFCompressedGraph readFrom(java.io.InputStream is,
                                         com.netflix.nfgraph.util.ByteSegmentPool memoryPool)
                                  throws java.io.IOException

When using a ByteSegmentPool, this method will borrow arrays used to construct the NFCompressedGraph from that pool.

Note that because the ByteSegmentPool is NOT thread-safe, this this call is also NOT thread-safe. It is up to implementations to ensure that only a single update thread is accessing this memory pool at any given time.

Throws:

java.io.IOException

destroy

public void destroy()

When using a ByteSegmentPool, this method will return all borrowed arrays back to that pool.

Note that because the ByteSegmentPool is NOT thread-safe, this this call is also NOT thread-safe. It is up to implementations to ensure that only a single update thread is accessing this memory pool at any given time.