textractor.mg4j.docstore
Class DocumentStoreReader

java.lang.Object
  textractor.mg4j.docstore.DocumentStoreReader

All Implemented Interfaces:

Closeable

public final class DocumentStoreReader
extends Object
implements Closeable

Access a DocumentStore on disk. User: Fabien Campagne Date: Oct 29, 2005 Time: 5:17:17 PM To change this template use File | Settings | File Templates.

Field Summary

static int

DOCUMENT_NOT_FOUND

Constructor Summary

DocumentStoreReader(DocumentIndexManager docmanager)
Initialize a document store reader for the "text" index.

DocumentStoreReader(IndexDetails indexDetailsVal, boolean readPmidsVal)
Initialize a document store reader for the inex specified by indexDetailsVal.

DocumentStoreReader(IndexDetails indexDetailsVal, int maxReads, boolean readPmidsVal)
Initialize a document store reader for the inex specified by indexDetailsVal.

Method Summary

void	close() Closes this reader and releases any system resources associated with it.
MutableString	document(int documentIndex) Retrieves a document from this document store.
int	document(int documentIndex, List<Integer> result) Retrieves a document from this document store.
void	document(int documentIndex, MutableString result) Retrieves a document from this document store.
int	frequencies(int documentIndex, int[] termFrequencies, int[] numDocForTerm) Get frequencies.
int	getDocumentNumber(long pmid) Retrieve the document number that corresponds to a given PMID.
int	getNumberOfDocuments() Get the total number of documents in the index associated with this document store.
int	getNumberOfTerms() Get the total number of terms in the index associated with this document store.
long	getPMID(int documentNumber) Retrieve the PMID that corresponds to a given document number.
int[]	getTermPermutation() Get term permutation.
boolean	isPositionsAvailable() Does this document store contain postion information?
List<IntRange>	positions(int documentIndex) Get the range of positions that this term occupied in the original document source.
void	readPMIDs() Read PMID information.

Methods inherited from class java.lang.Object

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

Field Detail

DOCUMENT_NOT_FOUND

public static final int DOCUMENT_NOT_FOUND

See Also:

Constant Field Values

Constructor Detail

DocumentStoreReader

public DocumentStoreReader(DocumentIndexManager docmanager)
                    throws IOException

Initialize a document store reader for the "text" index. This will read pmid values.

Parameters:

docmanager - the document index manager

Throws:

IOException - When docstore files cannot be read with the given basename.

DocumentStoreReader

public DocumentStoreReader(IndexDetails indexDetailsVal,
                           boolean readPmidsVal)
                    throws IOException

Initialize a document store reader for the inex specified by indexDetailsVal. It is only necessary to "readPmids" if reading from the "text" index.

Parameters:

indexDetailsVal - the document index to read the documents for

readPmidsVal - if true, the pmids file will be read

Throws:

IOException - When docstore files cannot be read with the given basename.

DocumentStoreReader

public DocumentStoreReader(IndexDetails indexDetailsVal,
                           int maxReads,
                           boolean readPmidsVal)
                    throws IOException

Initialize a document store reader for the inex specified by indexDetailsVal. It is only necessary to "readPmids" if reading from the "text" index.

Parameters:

indexDetailsVal - the document index to read the documents for

maxReads - xx

readPmidsVal - if true, the pmids file will be read

Throws:

IOException - When docstore files cannot be read with the given basename.

Method Detail

readPMIDs

public void readPMIDs()
               throws IOException

Read PMID information. This operation is optional. If performed, getPMID can be used.

Throws:

IOException - if the pmid map file cannot be read

See Also:

getPMID(int)

getPMID

public long getPMID(int documentNumber)

Retrieve the PMID that corresponds to a given document number. This method requires that PMID information has been read.

Parameters:

documentNumber - Document for which the PMID is sought

Returns:

PMID of the article corresponding to the document number

See Also:

readPMIDs()

getDocumentNumber

public int getDocumentNumber(long pmid)

Retrieve the document number that corresponds to a given PMID. This method requires that PMID information has been read. Note also that this is an O(n) operation where n is the number of documents in the store.

Parameters:

pmid - PMID for which the document number is sought

Returns:

document number of the article corresponding to the PMID or #DOCUMENT_NOT_FOUND (-1) if not found.

See Also:

readPMIDs()

document

public MutableString document(int documentIndex)
                       throws IOException

Retrieves a document from this document store.

Parameters:

documentIndex - the document index number to read

Returns:

The text of this document.

Throws:

IOException - error reading the data

document

public void document(int documentIndex,
                     MutableString result)
              throws IOException

Retrieves a document from this document store.

Parameters:

documentIndex - the document index number to read

result - Text of the document will be appended to this MutableString.

Throws:

IOException - error reading the data

document

public int document(int documentIndex,
                    List<Integer> result)
             throws IOException

Retrieves a document from this document store. The document is represented as a list of integer, where each integer codes for a word. Word coding is given by the document manager this document store is associated to.

Parameters:

documentIndex - Index of the document to retrieve.

result - Words of the document will be appended to this IntList.

Returns:

nothing useful? a zero, it appears.

Throws:

IOException - error reading the data

getTermPermutation

public int[] getTermPermutation()

Get term permutation.

frequencies

public int frequencies(int documentIndex,
                       int[] termFrequencies,
                       int[] numDocForTerm)
                throws IOException

Get frequencies.

Throws:

IOException

positions

public List<IntRange> positions(int documentIndex)
                         throws IOException

Get the range of positions that this term occupied in the original document source.

Parameters:

documentIndex - index of the document to get the positions for

Returns:

A range of positons. This will be null if this document store does not contain positon information

Throws:

IOException - if there is a problem reading the positions

See Also:

isPositionsAvailable()

isPositionsAvailable

public boolean isPositionsAvailable()

Does this document store contain postion information?

Returns:

true if the document store has postion information

getNumberOfTerms

public int getNumberOfTerms()

Get the total number of terms in the index associated with this document store.

Returns:

the number of terms

getNumberOfDocuments

public int getNumberOfDocuments()

Get the total number of documents in the index associated with this document store.

Returns:

the number of documents

close

public void close()
           throws IOException

Closes this reader and releases any system resources associated with it. If the reader is already closed then invoking this method has no effect.

Specified by:

close in interface Closeable

Throws:

IOException - if an I/O error occurs