LUCENE-2864: add FieldInvertState.getMaxTermFrequency

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1058939 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Robert Muir 2011-01-14 11:00:42 +00:00
parent 5a37511642
commit 9ea3019edb
4 changed files with 134 additions and 1 deletions

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@ -737,6 +737,10 @@ New features
is no longer needed and discouraged for that use case. Directly wrapping
Query improves performance, as out-of-order collection is now supported.
(Uwe Schindler)
* LUCENE-2864: Add getMaxTermFrequency (maximum within-document TF) to
FieldInvertState so that it can be used in Similarity.computeNorm.
(Robert Muir)
Optimizations

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@ -30,6 +30,7 @@ public final class FieldInvertState {
int length;
int numOverlap;
int offset;
int maxTermFrequency;
float boost;
AttributeSource attributeSource;
@ -53,6 +54,7 @@ public final class FieldInvertState {
length = 0;
numOverlap = 0;
offset = 0;
maxTermFrequency = 0;
boost = docBoost;
attributeSource = null;
}
@ -110,6 +112,15 @@ public final class FieldInvertState {
public void setBoost(float boost) {
this.boost = boost;
}
/**
* Get the maximum term-frequency encountered for any term in the field. A
* field containing "the quick brown fox jumps over the lazy dog" would have
* a value of 2, because "the" appears twice.
*/
public int getMaxTermFrequency() {
return maxTermFrequency;
}
public AttributeSource getAttributeSource() {
return attributeSource;

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@ -125,6 +125,7 @@ final class FreqProxTermsWriterPerField extends TermsHashConsumerPerField implem
postings.docFreqs[termID] = 1;
writeProx(termID, fieldState.position);
}
fieldState.maxTermFrequency = Math.max(1, fieldState.maxTermFrequency);
}
@Override
@ -158,11 +159,12 @@ final class FreqProxTermsWriterPerField extends TermsHashConsumerPerField implem
termsHashPerField.writeVInt(0, postings.docFreqs[termID]);
}
postings.docFreqs[termID] = 1;
fieldState.maxTermFrequency = Math.max(1, fieldState.maxTermFrequency);
postings.lastDocCodes[termID] = (docState.docID - postings.lastDocIDs[termID]) << 1;
postings.lastDocIDs[termID] = docState.docID;
writeProx(termID, fieldState.position);
} else {
postings.docFreqs[termID]++;
fieldState.maxTermFrequency = Math.max(fieldState.maxTermFrequency, ++postings.docFreqs[termID]);
writeProx(termID, fieldState.position-postings.lastPositions[termID]);
}
}

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@ -0,0 +1,116 @@
package org.apache.lucene.index;
/**
* 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.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.analysis.MockTokenizer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.search.DefaultSimilarity;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.util._TestUtil;
/**
* Tests the maxTermFrequency statistic in FieldInvertState
*/
public class TestMaxTermFrequency extends LuceneTestCase {
Directory dir;
IndexReader reader;
/* expected maxTermFrequency values for our documents */
ArrayList<Integer> expected = new ArrayList<Integer>();
@Override
public void setUp() throws Exception {
super.setUp();
dir = newDirectory();
IndexWriterConfig config = newIndexWriterConfig(TEST_VERSION_CURRENT,
new MockAnalyzer(MockTokenizer.SIMPLE, true));
config.setSimilarity(new TestSimilarity());
RandomIndexWriter writer = new RandomIndexWriter(random, dir, config);
Document doc = new Document();
Field foo = newField("foo", "", Field.Store.NO, Field.Index.ANALYZED);
doc.add(foo);
for (int i = 0; i < 100; i++) {
foo.setValue(addValue());
writer.addDocument(doc);
}
reader = writer.getReader();
writer.close();
}
@Override
public void tearDown() throws Exception {
reader.close();
dir.close();
super.tearDown();
}
public void test() throws Exception {
byte fooNorms[] = MultiNorms.norms(reader, "foo");
for (int i = 0; i < reader.maxDoc(); i++)
assertEquals(expected.get(i).intValue(), fooNorms[i] & 0xff);
}
/**
* Makes a bunch of single-char tokens (the max freq will at most be 255).
* shuffles them around, and returns the whole list with Arrays.toString().
* This works fine because we use lettertokenizer.
* puts the max-frequency term into expected, to be checked against the norm.
*/
private String addValue() {
List<String> terms = new ArrayList<String>();
int maxCeiling = _TestUtil.nextInt(random, 0, 255);
int max = 0;
for (char ch = 'a'; ch <= 'z'; ch++) {
int num = _TestUtil.nextInt(random, 0, maxCeiling);
for (int i = 0; i < num; i++)
terms.add(Character.toString(ch));
max = Math.max(max, num);
}
expected.add(max);
Collections.shuffle(terms, random);
return Arrays.toString(terms.toArray(new String[terms.size()]));
}
/**
* Simple similarity that encodes maxTermFrequency directly as a byte
*/
class TestSimilarity extends DefaultSimilarity {
@Override
public byte encodeNormValue(float f) {
return (byte) f;
}
@Override
public float decodeNormValue(byte b) {
return (float) b;
}
@Override
public float computeNorm(String field, FieldInvertState state) {
return (float) state.getMaxTermFrequency();
}
}
}