org.terrier.structures.postings.bit

Class BlockFieldIterablePosting

java.lang.Object

org.terrier.structures.postings.BasicPostingImpl

org.terrier.structures.postings.bit.BasicIterablePosting

org.terrier.structures.postings.bit.BlockFieldIterablePosting

All Implemented Interfaces:

Closeable, Serializable, AutoCloseable, org.apache.hadoop.io.Writable, BlockPosting, FieldPosting, IterablePosting, Posting, WritablePosting

public class BlockFieldIterablePosting
extends BasicIterablePosting
implements BlockPosting, FieldPosting

class BlockFieldIterablePosting

See Also:

Serialized Form

Field Summary

Fields inherited from class org.terrier.structures.postings.bit.BasicIterablePosting

bitFileReader, doi, numEntries

Fields inherited from class org.terrier.structures.postings.BasicPostingImpl

dl, id, tf

Fields inherited from interface org.terrier.structures.postings.IterablePosting

EOL

Constructor Summary

Constructors

Constructor and Description
BlockFieldIterablePosting(BitIn _bitFileReader, int _numEntries, DocumentIndex doi, int _fieldCount) Make a new posting iterator that is read from a BitIn stream.
BlockFieldIterablePosting(int _fieldCount) Make a new posting that can be loaded using Writable methods

Method Summary

Methods

Modifier and Type	Method and Description
WritablePosting	asWritablePosting() Copies this posting to one free of an iterator.
int[]	getFieldFrequencies() Returns the frequencies of the term in each field of the document
int[]	getFieldLengths() Returns the lengths of the each fields in the current document
int[]	getPositions() Return positions of occurrences
int	next() Move this iterator to the next posting.
void	readFields(DataInput in) Reads the a single posting (not an iterable posting - use BitPostingIndex for that)
void	setFieldLengths(int[] fl) .
String	toString() Makes a human readable form of this posting
void	write(DataOutput out) Writes the current posting (not an iterable posting - use DirectInvertedOutputStream for that).

Methods inherited from class org.terrier.structures.postings.bit.BasicIterablePosting

close, endOfPostings, getDocumentLength, next

Methods inherited from class org.terrier.structures.postings.BasicPostingImpl

getFrequency, getId, setDocumentLength, setId, setTf

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.terrier.structures.postings.Posting

getDocumentLength, getFrequency, getId, setId

Constructor Detail

BlockFieldIterablePosting

public BlockFieldIterablePosting(int _fieldCount)

Make a new posting that can be loaded using Writable methods

Parameters:

_fieldCount - number of fields to expect

BlockFieldIterablePosting

public BlockFieldIterablePosting(BitIn _bitFileReader,
                         int _numEntries,
                         DocumentIndex doi,
                         int _fieldCount)
                          throws IOException

Make a new posting iterator that is read from a BitIn stream.

Parameters:

_bitFileReader - BitIn stream containing postings

_numEntries - number of postings to read from stream

doi - DocumentIndex to read document and field lengths from

_fieldCount - number of fields to expect

Throws:

IOException

Method Detail

next

public int next()
         throws IOException

Move this iterator to the next posting.

Specified by:

next in interface IterablePosting

Overrides:

next in class BasicIterablePosting

Returns:

id of next posting, or EOL if end of posting list

Throws:

IOException

getPositions

public int[] getPositions()

Return positions of occurrences

Specified by:

getPositions in interface BlockPosting

getFieldFrequencies

public int[] getFieldFrequencies()

Returns the frequencies of the term in each field of the document

Specified by:

getFieldFrequencies in interface FieldPosting

setFieldLengths

public void setFieldLengths(int[] fl)

. This operation is unsupported.

Specified by:

setFieldLengths in interface FieldPosting

getFieldLengths

public int[] getFieldLengths()

Returns the lengths of the each fields in the current document

Specified by:

getFieldLengths in interface FieldPosting

readFields

public void readFields(DataInput in)
                throws IOException

Reads the a single posting (not an iterable posting - use BitPostingIndex for that)

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Overrides:

readFields in class BasicPostingImpl

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Writes the current posting (not an iterable posting - use DirectInvertedOutputStream for that). Compression using this method is not expected to be comparable to bit-level compression.

Specified by:

write in interface org.apache.hadoop.io.Writable

Overrides:

write in class BasicPostingImpl

Throws:

IOException

asWritablePosting

public WritablePosting asWritablePosting()

Copies this posting to one free of an iterator. Kind of like a clone.

Specified by:

asWritablePosting in interface Posting

Overrides:

asWritablePosting in class BasicIterablePosting

Returns:

an identical posting, but which can be maniulated free of this iterator

toString

public String toString()

Makes a human readable form of this posting

Overrides:

toString in class BasicPostingImpl