org.apache.arrow.memory.DrillByteBufAllocator.java Source code

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Here is the source code for org.apache.arrow.memory.DrillByteBufAllocator.java

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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.arrow.memory;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.buffer.CompositeByteBuf;
import io.netty.buffer.ExpandableByteBuf;

/**
 * An implementation of ByteBufAllocator that wraps a Drill BufferAllocator. This allows the RPC layer to be accounted
 * and managed using Drill's BufferAllocator infrastructure. The only thin different from a typical BufferAllocator is
 * the signature and the fact that this Allocator returns ExpandableByteBufs which enable otherwise non-expandable
 * DrillBufs to be expandable.
 */
public class DrillByteBufAllocator implements ByteBufAllocator {

    private static final int DEFAULT_BUFFER_SIZE = 4096;
    private static final int DEFAULT_MAX_COMPOSITE_COMPONENTS = 16;

    private final BufferAllocator allocator;

    public DrillByteBufAllocator(BufferAllocator allocator) {
        this.allocator = allocator;
    }

    @Override
    public ByteBuf buffer() {
        return buffer(DEFAULT_BUFFER_SIZE);
    }

    @Override
    public ByteBuf buffer(int initialCapacity) {
        return new ExpandableByteBuf(allocator.buffer(initialCapacity), allocator);
    }

    @Override
    public ByteBuf buffer(int initialCapacity, int maxCapacity) {
        return buffer(initialCapacity);
    }

    @Override
    public ByteBuf ioBuffer() {
        return buffer();
    }

    @Override
    public ByteBuf ioBuffer(int initialCapacity) {
        return buffer(initialCapacity);
    }

    @Override
    public ByteBuf ioBuffer(int initialCapacity, int maxCapacity) {
        return buffer(initialCapacity);
    }

    @Override
    public ByteBuf directBuffer() {
        return buffer();
    }

    @Override
    public ByteBuf directBuffer(int initialCapacity) {
        return allocator.buffer(initialCapacity);
    }

    @Override
    public ByteBuf directBuffer(int initialCapacity, int maxCapacity) {
        return buffer(initialCapacity, maxCapacity);
    }

    @Override
    public CompositeByteBuf compositeBuffer() {
        return compositeBuffer(DEFAULT_MAX_COMPOSITE_COMPONENTS);
    }

    @Override
    public CompositeByteBuf compositeBuffer(int maxNumComponents) {
        return new CompositeByteBuf(this, true, maxNumComponents);
    }

    @Override
    public CompositeByteBuf compositeDirectBuffer() {
        return compositeBuffer();
    }

    @Override
    public CompositeByteBuf compositeDirectBuffer(int maxNumComponents) {
        return compositeBuffer(maxNumComponents);
    }

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

    @Override
    public ByteBuf heapBuffer() {
        throw fail();
    }

    @Override
    public ByteBuf heapBuffer(int initialCapacity) {
        throw fail();
    }

    @Override
    public ByteBuf heapBuffer(int initialCapacity, int maxCapacity) {
        throw fail();
    }

    @Override
    public CompositeByteBuf compositeHeapBuffer() {
        throw fail();
    }

    @Override
    public CompositeByteBuf compositeHeapBuffer(int maxNumComponents) {
        throw fail();
    }

    private RuntimeException fail() {
        throw new UnsupportedOperationException("Allocator doesn't support heap-based memory.");
    }

}