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 * to you under the Apache License, Version 2.0 (the
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package org.apache.http.nio.reactor;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.nio.charset.CharacterCodingException;

import org.apache.http.util.CharArrayBuffer;

Session output buffer for non-blocking connections. This interface facilitates intermediate buffering of output data streamed out to a destination channel and writing data to the buffer from a source, usually ByteBuffer or ReadableByteChannel. This interface also provides methods for writing lines of text. 
Since:
4.0/**
 * Session output buffer for non-blocking connections. This interface
 * facilitates intermediate buffering of output data streamed out to
 * a destination channel and writing data to the buffer from a source, usually
 * {@link ByteBuffer} or {@link ReadableByteChannel}. This interface also
 * provides methods for writing lines of text.
 *
 * @since 4.0
 */
public interface SessionOutputBuffer {

    
Determines if the buffer contains data.
Returns:
true if there is data in the buffer, false otherwise./**
     * Determines if the buffer contains data.
     *
     * @return {@code true} if there is data in the buffer,
     *   {@code false} otherwise.
     */
    boolean hasData();

    
Returns the length of this buffer.
Returns:
buffer length./**
     * Returns the length of this buffer.
     *
     * @return buffer length.
     */
    int length();

    
Makes an attempt to flush the content of this buffer to the given destination WritableByteChannel. 
Params:
channel – the destination channel.
Throws:
IOException – in case of an I/O error.
Returns:
The number of bytes written, possibly zero./**
     * Makes an attempt to flush the content of this buffer to the given
     * destination {@link WritableByteChannel}.
     *
     * @param channel the destination channel.
     * @return The number of bytes written, possibly zero.
     * @throws IOException in case of an I/O error.
     */
    int flush(WritableByteChannel channel)
        throws IOException;

    
Copies content of the source buffer into this buffer. The capacity of
the destination will be expanded in order to accommodate the entire
content of the source buffer.
Params:
src – the source buffer./**
     * Copies content of the source buffer into this buffer. The capacity of
     * the destination will be expanded in order to accommodate the entire
     * content of the source buffer.
     *
     * @param src the source buffer.
     */
    void write(ByteBuffer src);

    
Reads a sequence of bytes from the source channel into this buffer.
Params:
src – the source channel./**
     * Reads a sequence of bytes from the source channel into this buffer.
     *
     * @param src the source channel.
     */
    void write(ReadableByteChannel src)
        throws IOException;

    
Copies content of the source buffer into this buffer as one line of text
including a line delimiter. The capacity of the destination will be
expanded in order to accommodate the entire content of the source buffer.

The choice of a char encoding and line delimiter sequence is up to the
specific implementations of this interface.
Params:
src – the source buffer./**
     * Copies content of the source buffer into this buffer as one line of text
     * including a line delimiter. The capacity of the destination will be
     * expanded in order to accommodate the entire content of the source buffer.
     * <p>
     * The choice of a char encoding and line delimiter sequence is up to the
     * specific implementations of this interface.
     *
     * @param src the source buffer.
     */
    void writeLine(CharArrayBuffer src)
        throws CharacterCodingException;

    
Copies content of the given string into this buffer as one line of text
including a line delimiter.
The capacity of the destination will be expanded in order to accommodate
the entire string.

The choice of a char encoding and line delimiter sequence is up to the
specific implementations of this interface.
Params:
s – the string./**
     * Copies content of the given string into this buffer as one line of text
     * including a line delimiter.
     * The capacity of the destination will be expanded in order to accommodate
     * the entire string.
     * <p>
     * The choice of a char encoding and line delimiter sequence is up to the
     * specific implementations of this interface.
     *
     * @param s the string.
     */
    void writeLine(String s)
        throws IOException;

}