org.apache.flink.runtime.io.disk.RandomAccessOutputView 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.apache.flink.runtime.io.disk;
import java.io.EOFException;
import org.apache.flink.core.memory.MemorySegment;
import org.apache.flink.core.memory.SeekableDataOutputView;
import org.apache.flink.runtime.memory.AbstractPagedOutputView;
import org.apache.flink.util.MathUtils;
/**
*
*
*/
public class RandomAccessOutputView extends AbstractPagedOutputView implements SeekableDataOutputView
{
private final MemorySegment[] segments;
private int currentSegmentIndex;
private final int segmentSizeBits;
private final int segmentSizeMask;
public RandomAccessOutputView(MemorySegment[] segments, int segmentSize) {
this(segments, segmentSize, MathUtils.log2strict(segmentSize));
}
public RandomAccessOutputView(MemorySegment[] segments, int segmentSize, int segmentSizeBits) {
super(segments[0], segmentSize, 0);
if ((segmentSize & (segmentSize - 1)) != 0) {
throw new IllegalArgumentException("Segment size must be a power of 2!");
}
this.segments = segments;
this.segmentSizeBits = segmentSizeBits;
this.segmentSizeMask = segmentSize - 1;
}
@Override
protected MemorySegment nextSegment(MemorySegment current, int positionInCurrent) throws EOFException {
if (++this.currentSegmentIndex < this.segments.length) {
return this.segments[this.currentSegmentIndex];
} else {
throw new EOFException();
}
}
@Override
public void setWritePosition(long position) {
final int bufferNum = (int) (position >>> this.segmentSizeBits);
final int offset = (int) (position & this.segmentSizeMask);
this.currentSegmentIndex = bufferNum;
seekOutput(this.segments[bufferNum], offset);
}
}