edu.ucla.sspace.common

Class CachingOnDiskSemanticSpace

java.lang.Object

edu.ucla.sspace.common.CachingOnDiskSemanticSpace

All Implemented Interfaces:

SemanticSpace

public class CachingOnDiskSemanticSpace
extends Object
implements SemanticSpace

A SemanticSpace where most vector data is kept on disk, but frequently accessed data is kept in memory. This class is designed for large semantic spaces whose data will not fit in memory and whose usage pattern will frequently access a vector multiple times.

The performance of this class is dependent on the format of the backing vector data; .sspace files in binary or sparse binary format will likely be faster for accessing the data due to it being in its native format.

The getWords method will return words in the order they are stored on disk. Accessing the words in this order will have to a significant performance improve over random access. Furtherore, random access to text and sparse text formatted matrices will have particularly poor performance for large semantic spaces, as the internal cursor to the data will have to restart from the beginning of the file.

This class is thread-safe.

See Also:

SemanticSpaceIO, OnDiskSemanticSpace

Constructor Summary

Constructors

Constructor and Description
CachingOnDiskSemanticSpace(File file) Creates a new instance of CachingOnDiskSemanticSpace from the data in the specified file.
CachingOnDiskSemanticSpace(String filename) Creates a new instance of CachingOnDiskSemanticSpace from the data in the file with the specified name.

Method Summary

Methods

Modifier and Type	Method and Description
String	getSpaceName() Returns a unique string describing the name and configuration of this algorithm.
Vector	getVector(String word) Returns the semantic vector for the provided word.
int	getVectorLength() Returns the length of vectors in this semantic space.
Set<String>	getWords() Returns the set of words that are represented in this semantic space.
void	processDocument(BufferedReader document) Not supported; throws an UnsupportedOperationException if called.
void	processSpace(Properties props) Not supported; throws an UnsupportedOperationException if called.

Methods inherited from class java.lang.Object

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

Constructor Detail

CachingOnDiskSemanticSpace

public CachingOnDiskSemanticSpace(String filename)
                           throws IOException

Creates a new instance of CachingOnDiskSemanticSpace from the data in the file with the specified name.

Parameters:

filename - the name of a file containing a semantic space

Throws:

IOException - if any I/O exception occurs when reading the semantic space data from the file

CachingOnDiskSemanticSpace

public CachingOnDiskSemanticSpace(File file)
                           throws IOException

Creates a new instance of CachingOnDiskSemanticSpace from the data in the specified file.

Parameters:

file - a file containing a semantic space

Throws:

IOException - if any I/O exception occurs when reading the semantic space data from the fil

Method Detail

getSpaceName

public String getSpaceName()

Returns a unique string describing the name and configuration of this algorithm. Any configurable parameters that would affect the resulting semantic space should be expressed as a part of this name.

Specified by:

getSpaceName in interface SemanticSpace

getWords

public Set<String> getWords()

Returns the set of words that are represented in this semantic space.

Specified by:

getWords in interface SemanticSpace

Returns:

the set of words that are represented in this semantic space.

getVector

public Vector getVector(String word)

Returns the semantic vector for the provided word. If the word is in the semantic space, its vector will be temporarily loaded into memory so that subsequent calls will not need to go to disk. As memory pressure increases, the vector will be discarded.

Specified by:

getVector in interface SemanticSpace

Parameters:

word - a word that may be in the semantic space

Returns:

The Vector for the provided word or null if the word was not in the space.

Throws:

IOError - if any IOException occurs when reading the data from the underlying semantic space file.

getVectorLength

public int getVectorLength()

Returns the length of vectors in this semantic space. Implementations are left free to define whether the returned value is valid before processSpace is called.

Specified by:

getVectorLength in interface SemanticSpace

processDocument

public void processDocument(BufferedReader document)

Not supported; throws an UnsupportedOperationException if called.

Specified by:

processDocument in interface SemanticSpace

Parameters:

document - a reader that allows access to the text of the document

Throws:

an - UnsupportedOperationException if called.

processSpace

public void processSpace(Properties props)

Not supported; throws an UnsupportedOperationException if called.

Specified by:

processSpace in interface SemanticSpace

Parameters:

props - a set of properties and values that may be used to configure any exposed parameters of the algorithm.

Throws:

an - UnsupportedOperationException if called.