+++ /dev/null
-package org.apache.lucene.search;
-
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You 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.
- */
-
-import java.io.IOException;
-
-import org.apache.lucene.index.TermDocs;
-
-/** Expert: A <code>Scorer</code> for documents matching a <code>Term</code>.
- */
-final class TermScorer extends Scorer {
- private TermDocs termDocs;
- private byte[] norms;
- private float weightValue;
- private int doc = -1;
- private int freq;
-
- private final int[] docs = new int[32]; // buffered doc numbers
- private final int[] freqs = new int[32]; // buffered term freqs
- private int pointer;
- private int pointerMax;
-
- private static final int SCORE_CACHE_SIZE = 32;
- private float[] scoreCache = new float[SCORE_CACHE_SIZE];
-
- /**
- * Construct a <code>TermScorer</code>.
- *
- * @param weight
- * The weight of the <code>Term</code> in the query.
- * @param td
- * An iterator over the documents matching the <code>Term</code>.
- * @param similarity
- * The </code>Similarity</code> implementation to be used for score
- * computations.
- * @param norms
- * The field norms of the document fields for the <code>Term</code>.
- */
- TermScorer(Weight weight, TermDocs td, Similarity similarity, byte[] norms) {
- super(similarity, weight);
-
- this.termDocs = td;
- this.norms = norms;
- this.weightValue = weight.getValue();
-
- for (int i = 0; i < SCORE_CACHE_SIZE; i++)
- scoreCache[i] = getSimilarity().tf(i) * weightValue;
- }
-
- @Override
- public void score(Collector c) throws IOException {
- score(c, Integer.MAX_VALUE, nextDoc());
- }
-
- // firstDocID is ignored since nextDoc() sets 'doc'
- @Override
- protected boolean score(Collector c, int end, int firstDocID) throws IOException {
- c.setScorer(this);
- while (doc < end) { // for docs in window
- c.collect(doc); // collect score
-
- if (++pointer >= pointerMax) {
- pointerMax = termDocs.read(docs, freqs); // refill buffers
- if (pointerMax != 0) {
- pointer = 0;
- } else {
- termDocs.close(); // close stream
- doc = Integer.MAX_VALUE; // set to sentinel value
- return false;
- }
- }
- doc = docs[pointer];
- freq = freqs[pointer];
- }
- return true;
- }
-
- @Override
- public int docID() { return doc; }
-
- @Override
- public float freq() {
- return freq;
- }
-
- /**
- * Advances to the next document matching the query. <br>
- * The iterator over the matching documents is buffered using
- * {@link TermDocs#read(int[],int[])}.
- *
- * @return the document matching the query or NO_MORE_DOCS if there are no more documents.
- */
- @Override
- public int nextDoc() throws IOException {
- pointer++;
- if (pointer >= pointerMax) {
- pointerMax = termDocs.read(docs, freqs); // refill buffer
- if (pointerMax != 0) {
- pointer = 0;
- } else {
- termDocs.close(); // close stream
- return doc = NO_MORE_DOCS;
- }
- }
- doc = docs[pointer];
- freq = freqs[pointer];
- return doc;
- }
-
- @Override
- public float score() {
- assert doc != -1;
- float raw = // compute tf(f)*weight
- freq < SCORE_CACHE_SIZE // check cache
- ? scoreCache[freq] // cache hit
- : getSimilarity().tf(freq)*weightValue; // cache miss
-
- return norms == null ? raw : raw * getSimilarity().decodeNormValue(norms[doc]); // normalize for field
- }
-
- /**
- * Advances to the first match beyond the current whose document number is
- * greater than or equal to a given target. <br>
- * The implementation uses {@link TermDocs#skipTo(int)}.
- *
- * @param target
- * The target document number.
- * @return the matching document or NO_MORE_DOCS if none exist.
- */
- @Override
- public int advance(int target) throws IOException {
- // first scan in cache
- for (pointer++; pointer < pointerMax; pointer++) {
- if (docs[pointer] >= target) {
- freq = freqs[pointer];
- return doc = docs[pointer];
- }
- }
-
- // not found in cache, seek underlying stream
- boolean result = termDocs.skipTo(target);
- if (result) {
- pointerMax = 1;
- pointer = 0;
- docs[pointer] = doc = termDocs.doc();
- freqs[pointer] = freq = termDocs.freq();
- } else {
- doc = NO_MORE_DOCS;
- }
- return doc;
- }
-
- /** Returns a string representation of this <code>TermScorer</code>. */
- @Override
- public String toString() { return "scorer(" + weight + ")"; }
-
-}
fnp / pylucene.git / blobdiff