/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project 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 io.netty.buffer;

import io.netty.util.CharsetUtil;

import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.OutputStream;

An OutputStream which writes data to a ByteBuf. 
 A write operation against this stream will occur at the writerIndex of its underlying buffer and the writerIndex will increase during the write operation. 
 This stream implements DataOutput for your convenience. The endianness of the stream is not always big endian but depends on the endianness of the underlying buffer. 
See Also:
ByteBufInputStream/**
 * An {@link OutputStream} which writes data to a {@link ByteBuf}.
 * <p>
 * A write operation against this stream will occur at the {@code writerIndex}
 * of its underlying buffer and the {@code writerIndex} will increase during
 * the write operation.
 * <p>
 * This stream implements {@link DataOutput} for your convenience.
 * The endianness of the stream is not always big endian but depends on
 * the endianness of the underlying buffer.
 *
 * @see ByteBufInputStream
 */
public class ByteBufOutputStream extends OutputStream implements DataOutput {

    private final ByteBuf buffer;
    private final int startIndex;
    private final DataOutputStream utf8out = new DataOutputStream(this);

    
Creates a new stream which writes data to the specified buffer. /**
     * Creates a new stream which writes data to the specified {@code buffer}.
     */
    public ByteBufOutputStream(ByteBuf buffer) {
        if (buffer == null) {
            throw new NullPointerException("buffer");
        }
        this.buffer = buffer;
        startIndex = buffer.writerIndex();
    }

    
Returns the number of written bytes by this stream so far.
/**
     * Returns the number of written bytes by this stream so far.
     */
    public int writtenBytes() {
        return buffer.writerIndex() - startIndex;
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        if (len == 0) {
            return;
        }

        buffer.writeBytes(b, off, len);
    }

    @Override
    public void write(byte[] b) throws IOException {
        buffer.writeBytes(b);
    }

    @Override
    public void write(int b) throws IOException {
        buffer.writeByte(b);
    }

    @Override
    public void writeBoolean(boolean v) throws IOException {
        buffer.writeBoolean(v);
    }

    @Override
    public void writeByte(int v) throws IOException {
        buffer.writeByte(v);
    }

    @Override
    public void writeBytes(String s) throws IOException {
        buffer.writeCharSequence(s, CharsetUtil.US_ASCII);
    }

    @Override
    public void writeChar(int v) throws IOException {
        buffer.writeChar(v);
    }

    @Override
    public void writeChars(String s) throws IOException {
        int len = s.length();
        for (int i = 0 ; i < len ; i ++) {
            buffer.writeChar(s.charAt(i));
        }
    }

    @Override
    public void writeDouble(double v) throws IOException {
        buffer.writeDouble(v);
    }

    @Override
    public void writeFloat(float v) throws IOException {
        buffer.writeFloat(v);
    }

    @Override
    public void writeInt(int v) throws IOException {
        buffer.writeInt(v);
    }

    @Override
    public void writeLong(long v) throws IOException {
        buffer.writeLong(v);
    }

    @Override
    public void writeShort(int v) throws IOException {
        buffer.writeShort((short) v);
    }

    @Override
    public void writeUTF(String s) throws IOException {
        utf8out.writeUTF(s);
    }

    
Returns the buffer where this stream is writing data.
/**
     * Returns the buffer where this stream is writing data.
     */
    public ByteBuf buffer() {
        return buffer;
    }
}