Buffer source API

BufferSource.java

/*
 * JBoss, Home of Professional Open Source
 *
 * Copyright 2015 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed 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.xnio;

import java.nio.BufferOverflowException;
import java.nio.ByteBuffer;
import java.util.function.Supplier;

/**
 * A supplier of populated {@link ByteBuffer} instances which are {@linkplain ByteBuffer#flip() flipped} for emptying.
 *
 * @author <a href="mailto:[email protected]">David M. Lloyd</a>
 */
public interface BufferSource extends Supplier<ByteBuffer> {

    /**
     * Get the next byte buffer.  Return {@code null} if there are no available buffers.  The same buffer will be
     * returned until the contents of that buffer have been emptied.
     *
     * @return the next byte buffer, or {@code null} if there are no more buffers available
     */
    ByteBuffer get();

    /**
     * Get the number of bytes available by this supplier.
     *
     * @return the number of bytes available by this supplier
     */
    int bytesAvailable();

    /**
     * Pre-fill the current buffer so that the number of available bytes is equal to or greater than {@code size}.  The
     * given {@code size} minus the remaining byte count of the current buffer may not exceed {@link #bytesAvailable()}.
     * The position of the buffer or the buffer instance itself may change if it has to be compacted to satisfy the size.
     * If the buffer cannot accommodate the size, an exception is thrown.  All implementations are required to support
     * up to 64 bytes or the current buffer's current capacity, whichever is larger.
     *
     * @param size the amount of data required in the current buffer
     * @throws IllegalArgumentException if {@code size} is less than zero or there is not enough data available to
     *      prefill the first buffer
     * @throws BufferOverflowException if the first buffer is not large enough to support {@code size}
     */
    void prefill(int size) throws IllegalArgumentException, BufferOverflowException;
}

StreamOutputChannel.java

package org.xnio.channels.async;

import static org.xnio._private.Messages.msg;

import java.io.IOException;
import java.nio.channels.FileChannel;

import org.xnio.BufferSource;
import org.xnio.IoCallback;
import org.xnio.OptionMap;
import org.xnio.Options;

/**
 * @author <a href="mailto:[email protected]">David M. Lloyd</a>
 */
public interface StreamOutputChannel extends AsynchronousChannel {
    // ...

    <T> void write(BufferSource bufferSource, long minLength, long maxLength, IoCallback<T> callback, T attachment);

    // ...
}