com.sun.labs.minion.classification
Class ClusterPostings

java.lang.Object
  com.sun.labs.minion.indexer.postings.IDPostings
      com.sun.labs.minion.indexer.postings.IDFreqPostings
          com.sun.labs.minion.indexer.postings.DocumentVectorPostings
              com.sun.labs.minion.classification.ClusterPostings

All Implemented Interfaces:

MergeablePostings, Postings

public class ClusterPostings
extends DocumentVectorPostings

Postings for the cluster documents in the cluster partition. These are similar in their behavior to DocumentVectorPostings in that occurences do not need to be added to them in order. Unlike DVP, the cluster postings extends that functionality into the merge behavior. Postings need not be appended in order -- that is, the append method is implemented as a merge.

Nested Class Summary

Nested classes/interfaces inherited from class com.sun.labs.minion.indexer.postings.IDFreqPostings

IDFreqPostings.IDFreqIterator

Nested classes/interfaces inherited from class com.sun.labs.minion.indexer.postings.IDPostings

IDPostings.IDIterator

Field Summary

protected static java.lang.String

logTag

Fields inherited from class com.sun.labs.minion.indexer.postings.DocumentVectorPostings

entries

Fields inherited from class com.sun.labs.minion.indexer.postings.IDFreqPostings

freq, freqs, maxfdt, to

Fields inherited from class com.sun.labs.minion.indexer.postings.IDPostings

curr, dataStart, ids, lastID, nIDs, nSkips, post, prevID, skipID, skipPos, skipSize

Constructor Summary

ClusterPostings()
Creates a set of postings suitable for use during indexing.

ClusterPostings(ReadableBuffer b)
Creates a set of postings suitable for use during querying.

Method Summary

void	append(Postings p, int start, int[] idMap) Appends another set of postings to this one, removing any data associated with deleted documents.
void	remap(int[] idMap) Writes the in-memory frequency array out to the postings buffers.

Methods inherited from class com.sun.labs.minion.indexer.postings.DocumentVectorPostings

add, finish, getWeightedFeatures, merge, size

Methods inherited from class com.sun.labs.minion.indexer.postings.IDFreqPostings

encode, getMaxFDT, getTotalOccurrences, iterator, recodeID

Methods inherited from class com.sun.labs.minion.indexer.postings.IDPostings

addSkip, append, getBuffers, getLastID, getN, setSkipSize, skip

Methods inherited from class java.lang.Object

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

Field Detail

logTag

protected static java.lang.String logTag

Constructor Detail

ClusterPostings

public ClusterPostings()

Creates a set of postings suitable for use during indexing.

ClusterPostings

public ClusterPostings(ReadableBuffer b)

Creates a set of postings suitable for use during querying.

Parameters:

b - a buffer containing the encoded postings.

Method Detail

append

public void append(Postings p,
                   int start,
                   int[] idMap)

Appends another set of postings to this one, removing any data associated with deleted documents.

Specified by:

append in interface Postings

Overrides:

append in class IDPostings

Parameters:

p - The postings to append. Implementers can safely assume that the postings being passed in are of the same class as the implementing class.

start - The new starting document ID for the partition that the entry was drawn from.

idMap - A map from old IDs in the given postings to new IDs with gaps removed for deleted data. If this is null, then there are no deleted documents.

remap

public void remap(int[] idMap)

Writes the in-memory frequency array out to the postings buffers. This is done in the remap method for consistency with the super class. Otherwise, this would probably be done in finish(). Since the clusters' contents will already have been remapped at this point (from the append method) we just flush the contents directly out to disk.

Specified by:

remap in interface Postings

Overrides:

remap in class DocumentVectorPostings

Parameters:

idMap - a map from old IDs to new IDs -- ignored