Package it.unimi.di.big.mg4j.util

Class DocumentSequenceImmutableSequentialGraph

java.lang.Object

it.unimi.dsi.big.webgraph.ImmutableGraph

it.unimi.dsi.big.webgraph.ImmutableSequentialGraph

it.unimi.di.big.mg4j.util.DocumentSequenceImmutableSequentialGraph

All Implemented Interfaces:

FlyweightPrototype<it.unimi.dsi.big.webgraph.ImmutableGraph>

public class DocumentSequenceImmutableSequentialGraph
extends it.unimi.dsi.big.webgraph.ImmutableSequentialGraph

Exposes a document sequence as a (sequentially accessible) immutable graph, according to some virtual field provided by the documents in the sequence. A suitable VirtualDocumentResolver is used to associate node numbers to each fragment.

More precisely, the graph will have as many nodes as there are documents in the sequence, the k-th document (starting from 0) representing node number k. The successors of a document are obtained by extracting the virtual field from the document, turning each document specifier into a document number (using the given resolver, and discarding unresolved URLs).

Note that the current implementation does not support more than Integer.MAX_VALUE successors per node.

Nested Class Summary

Nested classes/interfaces inherited from class it.unimi.dsi.big.webgraph.ImmutableGraph

it.unimi.dsi.big.webgraph.ImmutableGraph.LoadMethod

Field Summary

Fields inherited from class it.unimi.dsi.big.webgraph.ImmutableGraph

GRAPHCLASS_PROPERTY_KEY, PROPERTIES_EXTENSION

Constructor Summary

Constructors

Constructor	Description
DocumentSequenceImmutableSequentialGraph(DocumentSequence sequence, String fieldName, VirtualDocumentResolver resolver)	Creates an immutable graph from a sequence.
DocumentSequenceImmutableSequentialGraph(String... arg)	Creates a new immutable graph with the specified arguments.

Method Summary

Modifier and Type	Method	Description
it.unimi.dsi.big.webgraph.ImmutableGraph	copy()
it.unimi.dsi.big.webgraph.NodeIterator	nodeIterator()
long	numNodes()
boolean	randomAccess()

Methods inherited from class it.unimi.dsi.big.webgraph.ImmutableSequentialGraph

outdegree, successorBigArray

Methods inherited from class it.unimi.dsi.big.webgraph.ImmutableGraph

basename, equals, hashCode, intNumNodes, load, load, load, loadMapped, loadMapped, loadOffline, loadOffline, loadOnce, loadSequential, loadSequential, nodeIterator, numArcs, outdegrees, store, store, successors, toString, wrap, wrap

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DocumentSequenceImmutableSequentialGraph

public DocumentSequenceImmutableSequentialGraph(DocumentSequence sequence,
                                                String fieldName,
                                                VirtualDocumentResolver resolver)

Creates an immutable graph from a sequence.

Parameters:

sequence - the sequence whence the immutable graph should be created.

fieldName - the name of the virtual field to be used to get the successors.

resolver - the resolver to be used to map document specs to node numbers.

DocumentSequenceImmutableSequentialGraph

public DocumentSequenceImmutableSequentialGraph(String... arg)
                                         throws IOException,
                                                ClassNotFoundException,
                                                IllegalArgumentException,
                                                IllegalAccessException,
                                                InvocationTargetException,
                                                InstantiationException,
                                                NoSuchMethodException

Creates a new immutable graph with the specified arguments.

Parameters:

arg - a 3-element array: the first is a specification of a DocumentSequence, the second is the name of a virtual field, and the third is the filename of a VirtualDocumentResolver.

Throws:

IOException

ClassNotFoundException

IllegalArgumentException

IllegalAccessException

InvocationTargetException

InstantiationException

NoSuchMethodException

Method Detail

copy

public it.unimi.dsi.big.webgraph.ImmutableGraph copy()

Specified by:

copy in interface FlyweightPrototype<it.unimi.dsi.big.webgraph.ImmutableGraph>

Overrides:

copy in class it.unimi.dsi.big.webgraph.ImmutableSequentialGraph

numNodes

public long numNodes()

Specified by:

numNodes in class it.unimi.dsi.big.webgraph.ImmutableGraph

randomAccess

public boolean randomAccess()

Overrides:

randomAccess in class it.unimi.dsi.big.webgraph.ImmutableSequentialGraph

nodeIterator

public it.unimi.dsi.big.webgraph.NodeIterator nodeIterator()

Overrides:

nodeIterator in class it.unimi.dsi.big.webgraph.ImmutableGraph