org.trypticon.luceneupgrader.lucene5.internal.lucene.util.packed.BlockPackedReader Maven / Gradle / Ivy
/*
* 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.
*/
package org.trypticon.luceneupgrader.lucene5.internal.lucene.util.packed;
import static org.trypticon.luceneupgrader.lucene5.internal.lucene.util.BitUtil.zigZagDecode;
import static org.trypticon.luceneupgrader.lucene5.internal.lucene.util.packed.AbstractBlockPackedWriter.BPV_SHIFT;
import static org.trypticon.luceneupgrader.lucene5.internal.lucene.util.packed.AbstractBlockPackedWriter.MAX_BLOCK_SIZE;
import static org.trypticon.luceneupgrader.lucene5.internal.lucene.util.packed.AbstractBlockPackedWriter.MIN_BLOCK_SIZE;
import static org.trypticon.luceneupgrader.lucene5.internal.lucene.util.packed.AbstractBlockPackedWriter.MIN_VALUE_EQUALS_0;
import static org.trypticon.luceneupgrader.lucene5.internal.lucene.util.packed.BlockPackedReaderIterator.readVLong;
import static org.trypticon.luceneupgrader.lucene5.internal.lucene.util.packed.PackedInts.checkBlockSize;
import static org.trypticon.luceneupgrader.lucene5.internal.lucene.util.packed.PackedInts.numBlocks;
import java.io.IOException;
import java.util.Collection;
import java.util.Collections;
import org.trypticon.luceneupgrader.lucene5.internal.lucene.store.IndexInput;
import org.trypticon.luceneupgrader.lucene5.internal.lucene.util.Accountable;
import org.trypticon.luceneupgrader.lucene5.internal.lucene.util.LongValues;
/**
* Provides random access to a stream written with {@link BlockPackedWriter}.
* @lucene.internal
*/
public final class BlockPackedReader extends LongValues implements Accountable {
private final int blockShift, blockMask;
private final long valueCount;
private final long[] minValues;
private final PackedInts.Reader[] subReaders;
private final long sumBPV;
/** Sole constructor. */
public BlockPackedReader(IndexInput in, int packedIntsVersion, int blockSize, long valueCount, boolean direct) throws IOException {
this.valueCount = valueCount;
blockShift = checkBlockSize(blockSize, MIN_BLOCK_SIZE, MAX_BLOCK_SIZE);
blockMask = blockSize - 1;
final int numBlocks = numBlocks(valueCount, blockSize);
long[] minValues = null;
subReaders = new PackedInts.Reader[numBlocks];
long sumBPV = 0;
for (int i = 0; i < numBlocks; ++i) {
final int token = in.readByte() & 0xFF;
final int bitsPerValue = token >>> BPV_SHIFT;
sumBPV += bitsPerValue;
if (bitsPerValue > 64) {
throw new IOException("Corrupted");
}
if ((token & MIN_VALUE_EQUALS_0) == 0) {
if (minValues == null) {
minValues = new long[numBlocks];
}
minValues[i] = zigZagDecode(1L + readVLong(in));
}
if (bitsPerValue == 0) {
subReaders[i] = new PackedInts.NullReader(blockSize);
} else {
final int size = (int) Math.min(blockSize, valueCount - (long) i * blockSize);
if (direct) {
final long pointer = in.getFilePointer();
subReaders[i] = PackedInts.getDirectReaderNoHeader(in, PackedInts.Format.PACKED, packedIntsVersion, size, bitsPerValue);
in.seek(pointer + PackedInts.Format.PACKED.byteCount(packedIntsVersion, size, bitsPerValue));
} else {
subReaders[i] = PackedInts.getReaderNoHeader(in, PackedInts.Format.PACKED, packedIntsVersion, size, bitsPerValue);
}
}
}
this.minValues = minValues;
this.sumBPV = sumBPV;
}
@Override
public long get(long index) {
assert index >= 0 && index < valueCount;
final int block = (int) (index >>> blockShift);
final int idx = (int) (index & blockMask);
return (minValues == null ? 0 : minValues[block]) + subReaders[block].get(idx);
}
@Override
public long ramBytesUsed() {
long size = 0;
for (PackedInts.Reader reader : subReaders) {
size += reader.ramBytesUsed();
}
return size;
}
@Override
public Collection getChildResources() {
return Collections.emptyList();
}
@Override
public String toString() {
long avgBPV = subReaders.length == 0 ? 0 : sumBPV / subReaders.length;
return getClass().getSimpleName() + "(blocksize=" + (1<