org.terrier.structures.postings
Class BlockIterablePosting

java.lang.Object
  org.terrier.structures.postings.BasicPostingImpl
      org.terrier.structures.postings.BasicIterablePosting
          org.terrier.structures.postings.BlockIterablePosting

All Implemented Interfaces:

java.io.Closeable, org.apache.hadoop.io.Writable, BlockPosting, IterablePosting, Posting, WritablePosting

public class BlockIterablePosting
extends BasicIterablePosting
implements BlockPosting

A writable block iterable posting list

Field Summary

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

bitFileReader, doi, numEntries

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

id, tf

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

EOL

Constructor Summary

BlockIterablePosting()
Constructs an instance of the BlockIterablePosting.

BlockIterablePosting(BitIn _bitFileReader, int _numEntries, DocumentIndex doi)
Constructs an instance of the BlockIterablePosting.

Method Summary

WritablePosting	asWritablePosting() Copies this posting to one free of an iterator.
int[]	getPositions() Return positions of occurrences
int	next() Move this iterator to the next posting.
void	readFields(java.io.DataInput in) Reads the a single posting (not an iterable posting - use BitPostingIndex for that)
java.lang.String	toString() Makes a human readable form of this posting
void	write(java.io.DataOutput out) Writes the current posting (not an iterable posting - use DirectInvertedOutputStream for that).

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

close, endOfPostings, getDocumentLength, next

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

getFrequency, getId, setId

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

BlockIterablePosting

public BlockIterablePosting()

Constructs an instance of the BlockIterablePosting.

BlockIterablePosting

public BlockIterablePosting(BitIn _bitFileReader,
                            int _numEntries,
                            DocumentIndex doi)
                     throws java.io.IOException

Constructs an instance of the BlockIterablePosting.

Parameters:

_bitFileReader -

_numEntries -

doi -

Throws:

java.io.IOException

Method Detail

next

public int next()
         throws java.io.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:

java.io.IOException

getPositions

public int[] getPositions()

Return positions of occurrences

Specified by:

getPositions in interface BlockPosting

readFields

public void readFields(java.io.DataInput in)
                throws java.io.IOException

Description copied from class: BasicPostingImpl

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:

java.io.IOException

write

public void write(java.io.DataOutput out)
           throws java.io.IOException

Description copied from class: BasicPostingImpl

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:

java.io.IOException

asWritablePosting

public WritablePosting asWritablePosting()

Description copied from class: BasicIterablePosting

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 java.lang.String toString()

Description copied from class: BasicPostingImpl

Makes a human readable form of this posting

Overrides:

toString in class BasicPostingImpl