package org.apache.lucene.codecs.pulsing;
/*
* 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.codecs.FieldsConsumer;
import org.apache.lucene.codecs.FieldsProducer;
import org.apache.lucene.codecs.PostingsBaseFormat;
import org.apache.lucene.codecs.PostingsFormat;
import org.apache.lucene.codecs.PostingsReaderBase;
import org.apache.lucene.codecs.PostingsWriterBase;
import org.apache.lucene.codecs.blocktree.BlockTreeTermsReader;
import org.apache.lucene.codecs.blocktree.BlockTreeTermsWriter;
import org.apache.lucene.index.SegmentReadState;
import org.apache.lucene.index.SegmentWriteState;
import org.apache.lucene.util.IOUtils;
/** This postings format "inlines" the postings for terms that have
* low docFreq. It wraps another postings format, which is used for
* writing the non-inlined terms.
*
* @lucene.experimental */
public abstract class PulsingPostingsFormat extends PostingsFormat {
private final int freqCutoff;
private final int minBlockSize;
private final int maxBlockSize;
private final PostingsBaseFormat wrappedPostingsBaseFormat;
public PulsingPostingsFormat(String name, PostingsBaseFormat wrappedPostingsBaseFormat, int freqCutoff) {
this(name, wrappedPostingsBaseFormat, freqCutoff, BlockTreeTermsWriter.DEFAULT_MIN_BLOCK_SIZE, BlockTreeTermsWriter.DEFAULT_MAX_BLOCK_SIZE);
}
/** Terms with freq <= freqCutoff are inlined into terms
* dict. */
public PulsingPostingsFormat(String name, PostingsBaseFormat wrappedPostingsBaseFormat, int freqCutoff, int minBlockSize, int maxBlockSize) {
super(name);
this.freqCutoff = freqCutoff;
this.minBlockSize = minBlockSize;
assert minBlockSize > 1;
this.maxBlockSize = maxBlockSize;
this.wrappedPostingsBaseFormat = wrappedPostingsBaseFormat;
}
@Override
public String toString() {
return getName() + "(freqCutoff=" + freqCutoff + " minBlockSize=" + minBlockSize + " maxBlockSize=" + maxBlockSize + ")";
}
@Override
public FieldsConsumer fieldsConsumer(SegmentWriteState state) throws IOException {
PostingsWriterBase docsWriter = null;
// Terms that have <= freqCutoff number of docs are
// "pulsed" (inlined):
PostingsWriterBase pulsingWriter = null;
// Terms dict
boolean success = false;
try {
docsWriter = wrappedPostingsBaseFormat.postingsWriterBase(state);
// Terms that have <= freqCutoff number of docs are
// "pulsed" (inlined):
pulsingWriter = new PulsingPostingsWriter(state, freqCutoff, docsWriter);
FieldsConsumer ret = new BlockTreeTermsWriter(state, pulsingWriter, minBlockSize, maxBlockSize);
success = true;
return ret;
} finally {
if (!success) {
IOUtils.closeWhileHandlingException(docsWriter, pulsingWriter);
}
}
}
@Override
public FieldsProducer fieldsProducer(SegmentReadState state) throws IOException {
PostingsReaderBase docsReader = null;
PostingsReaderBase pulsingReader = null;
boolean success = false;
try {
docsReader = wrappedPostingsBaseFormat.postingsReaderBase(state);
pulsingReader = new PulsingPostingsReader(state, docsReader);
FieldsProducer ret = new BlockTreeTermsReader(
state.directory, state.fieldInfos, state.segmentInfo,
pulsingReader,
state.context,
state.segmentSuffix,
state.termsIndexDivisor);
success = true;
return ret;
} finally {
if (!success) {
IOUtils.closeWhileHandlingException(docsReader, pulsingReader);
}
}
}
public int getFreqCutoff() {
return freqCutoff;
}
}