Package it.unimi.di.big.mg4j.document

Class ReplicatedDocumentFactory

java.lang.Object

it.unimi.di.big.mg4j.document.AbstractDocumentFactory

it.unimi.di.big.mg4j.document.ReplicatedDocumentFactory

All Implemented Interfaces:

DocumentFactory, FlyweightPrototype<DocumentFactory>, Serializable

public class ReplicatedDocumentFactory
extends AbstractDocumentFactory

A factory that replicates a given factory several times. A special case of a composite factory.

Note that in general replicated factories support only sequential access to field content (albeit skipping items is allowed).

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	ReplicatedDocumentFactory.ReplicatedDocument	A document obtained by replication of the underlying-factory document.

Nested classes/interfaces inherited from interface it.unimi.di.big.mg4j.document.DocumentFactory

DocumentFactory.FieldType

Field Summary

Fields

Modifier and Type	Field	Description
DocumentFactory	documentFactory	The document factory that will be replicated.
int	numberOfCopies	The number of copies.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ReplicatedDocumentFactory(DocumentFactory documentFactory, int numberOfCopies, String[] fieldName, Object2IntOpenHashMap<String> field2Index)

Method Summary

Modifier and Type	Method	Description
ReplicatedDocumentFactory	copy()
int	fieldIndex(String fieldName)	Returns the index of a field, given its symbolic name.
String	fieldName(int field)	Returns the symbolic name of a field.
DocumentFactory.FieldType	fieldType(int field)	Returns the type of a field.
Document	getDocument(InputStream rawContent, Reference2ObjectMap<Enum<?>,Object> metadata)	Returns the document obtained by parsing the given byte stream.
static DocumentFactory	getFactory(DocumentFactory documentFactory, int numberOfCopies, String[] fieldName)	Returns a document factory replicating the given factory.
int	numberOfFields()	Returns the number of fields present in the documents produced by this factory.

Methods inherited from class it.unimi.di.big.mg4j.document.AbstractDocumentFactory

ensureFieldIndex, toString

Methods inherited from class java.lang.Object

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

Field Detail

documentFactory

public final DocumentFactory documentFactory

The document factory that will be replicated.

numberOfCopies

public final int numberOfCopies

The number of copies.

Constructor Detail

ReplicatedDocumentFactory

protected ReplicatedDocumentFactory(DocumentFactory documentFactory,
                                    int numberOfCopies,
                                    String[] fieldName,
                                    Object2IntOpenHashMap<String> field2Index)

Method Detail

getFactory

public static DocumentFactory getFactory(DocumentFactory documentFactory,
                                         int numberOfCopies,
                                         String[] fieldName)

Returns a document factory replicating the given factory.

Parameters:

documentFactory - the factory that will be replicated.

numberOfCopies - the number of copies.

Returns:

a replicated document factory.

copy

public ReplicatedDocumentFactory copy()

numberOfFields

public int numberOfFields()

Description copied from interface: DocumentFactory

Returns the number of fields present in the documents produced by this factory.

Returns:

the number of fields present in the documents produced by this factory.

fieldName

public String fieldName(int field)

Description copied from interface: DocumentFactory

Returns the symbolic name of a field.

Parameters:

field - the index of a field (between 0 inclusive and DocumentFactory.numberOfFields() exclusive}).

Returns:

the symbolic name of the field-th field.

fieldIndex

public int fieldIndex(String fieldName)

Description copied from interface: DocumentFactory

Returns the index of a field, given its symbolic name.

Parameters:

fieldName - the name of a field of this factory.

Returns:

the corresponding index, or -1 if there is no field with name fieldName.

fieldType

public DocumentFactory.FieldType fieldType(int field)

Description copied from interface: DocumentFactory

Returns the type of a field.

The possible types are defined in DocumentFactory.FieldType.

Parameters:

field - the index of a field (between 0 inclusive and DocumentFactory.numberOfFields() exclusive}).

Returns:

the type of the field-th field.

getDocument

public Document getDocument(InputStream rawContent,
                            Reference2ObjectMap<Enum<?>,Object> metadata)
                     throws IOException

Description copied from interface: DocumentFactory

Returns the document obtained by parsing the given byte stream.

The parameter metadata actually replaces the lack of a simple keyword-based parameter-passing system in Java. This method might take several different type of “suggestions” which have been collected by the collection: typically, the document title, a URI representing the document, its MIME type, its encoding and so on. Some of this information might be set by default (as it happens, for instance, in a PropertyBasedDocumentFactory). Implementations of this method must consult the metadata provided by the collection, possibly complete them with default factory metadata, and proceed to the document construction.

Parameters:

rawContent - the raw content from which the document should be extracted; it must not be closed, as resource management is a responsibility of the DocumentCollection.

metadata - a map from enums (e.g., keys taken in PropertyBasedDocumentFactory) to various kind of objects.

Returns:

the document obtained by parsing the given character sequence.

Throws:

IOException