org.apache.lucene.index.ByteSliceWriter Maven / Gradle / Ivy
package org.apache.lucene.index;
import org.apache.lucene.store.DataOutput;
import org.apache.lucene.util.ByteBlockPool;
/*
* 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.
*/
/**
* Class to write byte streams into slices of shared
* byte[]. This is used by DocumentsWriter to hold the
* posting list for many terms in RAM.
*/
final class ByteSliceWriter extends DataOutput {
private byte[] slice;
private int upto;
private final ByteBlockPool pool;
int offset0;
public ByteSliceWriter(ByteBlockPool pool) {
this.pool = pool;
}
/**
* Set up the writer to write at address.
*/
public void init(int address) {
slice = pool.buffers[address >> ByteBlockPool.BYTE_BLOCK_SHIFT];
assert slice != null;
upto = address & ByteBlockPool.BYTE_BLOCK_MASK;
offset0 = address;
assert upto < slice.length;
}
/** Write byte into byte slice stream */
@Override
public void writeByte(byte b) {
assert slice != null;
if (slice[upto] != 0) {
upto = pool.allocSlice(slice, upto);
slice = pool.buffer;
offset0 = pool.byteOffset;
assert slice != null;
}
slice[upto++] = b;
assert upto != slice.length;
}
@Override
public void writeBytes(final byte[] b, int offset, final int len) {
final int offsetEnd = offset + len;
while(offset < offsetEnd) {
if (slice[upto] != 0) {
// End marker
upto = pool.allocSlice(slice, upto);
slice = pool.buffer;
offset0 = pool.byteOffset;
}
slice[upto++] = b[offset++];
assert upto != slice.length;
}
}
public int getAddress() {
return upto + (offset0 & DocumentsWriterPerThread.BYTE_BLOCK_NOT_MASK);
}
}