FileDocCategorySizeDatePackage
SegmentTermDocs.javaAPI DocApache Lucene 1.4.35619Mon Jun 14 02:15:24 BST 2004org.apache.lucene.index

SegmentTermDocs

public class SegmentTermDocs extends Object implements TermDocs
Copyright 2004 The Apache Software Foundation Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Fields Summary
protected SegmentReader
parent
private org.apache.lucene.store.InputStream
freqStream
private int
count
private int
df
private BitVector
deletedDocs
int
doc
int
freq
private int
skipInterval
private int
numSkips
private int
skipCount
private org.apache.lucene.store.InputStream
skipStream
private int
skipDoc
private long
freqPointer
private long
proxPointer
private long
skipPointer
private boolean
haveSkipped
Constructors Summary
SegmentTermDocs(SegmentReader parent)


   
            
    this.parent = parent;
    this.freqStream = (InputStream) parent.freqStream.clone();
    this.deletedDocs = parent.deletedDocs;
    this.skipInterval = parent.tis.getSkipInterval();
Methods Summary
public voidclose()

    freqStream.close();
    if (skipStream != null)
      skipStream.close();
public final intdoc()

 return doc;
public final intfreq()

 return freq;
public booleannext()

    while (true) {
      if (count == df)
        return false;

      int docCode = freqStream.readVInt();
      doc += docCode >>> 1;			  // shift off low bit
      if ((docCode & 1) != 0)			  // if low bit is set
        freq = 1;				  // freq is one
      else
        freq = freqStream.readVInt();		  // else read freq

      count++;

      if (deletedDocs == null || !deletedDocs.get(doc))
        break;
      skippingDoc();
    }
    return true;
public intread(int[] docs, int[] freqs)
Optimized implementation.

    final int length = docs.length;
    int i = 0;
    while (i < length && count < df) {

      // manually inlined call to next() for speed
      final int docCode = freqStream.readVInt();
      doc += docCode >>> 1;			  // shift off low bit
      if ((docCode & 1) != 0)			  // if low bit is set
        freq = 1;				  // freq is one
      else
        freq = freqStream.readVInt();		  // else read freq
      count++;

      if (deletedDocs == null || !deletedDocs.get(doc)) {
        docs[i] = doc;
        freqs[i] = freq;
        ++i;
      }
    }
    return i;
public voidseek(org.apache.lucene.index.Term term)

    TermInfo ti = parent.tis.get(term);
    seek(ti);
public voidseek(org.apache.lucene.index.TermEnum termEnum)

    TermInfo ti;
    
    // use comparison of fieldinfos to verify that termEnum belongs to the same segment as this SegmentTermDocs
    if (termEnum instanceof SegmentTermEnum && ((SegmentTermEnum) termEnum).fieldInfos == parent.fieldInfos)          // optimized case
      ti = ((SegmentTermEnum) termEnum).termInfo();
    else                                          // punt case
      ti = parent.tis.get(termEnum.term());
      
    seek(ti);
voidseek(org.apache.lucene.index.TermInfo ti)

    count = 0;
    if (ti == null) {
      df = 0;
    } else {
      df = ti.docFreq;
      doc = 0;
      skipDoc = 0;
      skipCount = 0;
      numSkips = df / skipInterval;
      freqPointer = ti.freqPointer;
      proxPointer = ti.proxPointer;
      skipPointer = freqPointer + ti.skipOffset;
      freqStream.seek(freqPointer);
      haveSkipped = false;
    }
protected voidskipProx(long proxPointer)
Overridden by SegmentTermPositions to skip in prox stream.

public booleanskipTo(int target)
Optimized implementation.
    if (df >= skipInterval) {                      // optimized case

      if (skipStream == null)
        skipStream = (InputStream) freqStream.clone(); // lazily clone

      if (!haveSkipped) {                          // lazily seek skip stream
        skipStream.seek(skipPointer);
        haveSkipped = true;
      }

      // scan skip data
      int lastSkipDoc = skipDoc;
      long lastFreqPointer = freqStream.getFilePointer();
      long lastProxPointer = -1;
      int numSkipped = -1 - (count % skipInterval);

      while (target > skipDoc) {
        lastSkipDoc = skipDoc;
        lastFreqPointer = freqPointer;
        lastProxPointer = proxPointer;
        
        if (skipDoc != 0 && skipDoc >= doc)
          numSkipped += skipInterval;
        
        if(skipCount >= numSkips)
          break;

        skipDoc += skipStream.readVInt();
        freqPointer += skipStream.readVInt();
        proxPointer += skipStream.readVInt();

        skipCount++;
      }
      
      // if we found something to skip, then skip it
      if (lastFreqPointer > freqStream.getFilePointer()) {
        freqStream.seek(lastFreqPointer);
        skipProx(lastProxPointer);

        doc = lastSkipDoc;
        count += numSkipped;
      }

    }

    // done skipping, now just scan
    do {
      if (!next())
        return false;
    } while (target > doc);
    return true;
  
protected voidskippingDoc()