org.apache.flink.runtime.state.gemini.engine.rm.GSharedUnreferencedByteBuffer Maven / Gradle / Ivy

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/*
 * 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.state.gemini.engine.rm;

import org.apache.flink.runtime.state.gemini.engine.exceptions.GeminiRuntimeException;

import java.nio.ByteBuffer;

/**
 * {@link GSharedUnreferencedByteBuffer} is a {@link GByteBuffer} that shared the actual buffer with another {@link GByteBuffer}.
 * We don't need to consider the reference count of it.
 * If the {@link GByteBuffer} that {@link GSharedUnreferencedByteBuffer} shard buffer with is released, read or write the data of
 * this {@link GSharedUnreferencedByteBuffer} will raise an exception.
 */
public class GSharedUnreferencedByteBuffer implements GByteBuffer {
	private final GByteBuffer buddy;
	private final int len;

	public GSharedUnreferencedByteBuffer(GByteBuffer gByteBuffer) {
		this.buddy = gByteBuffer;
		this.len = gByteBuffer.capacity();
	}

	@Override
	public int capacity() {
		return len;
	}

	@Override
	public ByteBuffer getByteBuffer() {
		if (isFreed()) {
			throw new GeminiRuntimeException("GSharedUnreferencedByteBuffer is released.");
		}
		return buddy.getByteBuffer();
	}

	@Override
	public void retain() {
	}

	@Override
	public void release() {
	}

	@Override
	public int refCnt() {
		return 0;
	}

	@Override
	public void doFree() throws GeminiRuntimeException {
	}

	@Override
	public boolean isFreed() {
		return buddy == null || buddy.isFreed();
	}

	@Override
	public FinalizableCleaner getCleaner() {
		return new AbstractGByteBufferReference.EmptyCleaner();
	}

	@Override
	public boolean isPooled() {
		return false;
	}

	@Override
	public void setSeqID(long seqID) {
	}

	@Override
	public long getSeqID() {
		return 0;
	}

	@Override
	public void close() {
	}

	@Override
	public boolean canSyncFree() {
		return true;
	}

	@Override
	public void setWaitSeqId() {
	}
}