/*

  * 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.giraph.utils;

 import java.io.ByteArrayOutputStream;

 import java.io.DataOutput;

 import java.io.DataOutputStream;

 import java.io.IOException;

 import java.util.Arrays;

 /**

  * Adds some functionality to ByteArrayOutputStream,

  * such as an option to write int value over previously written data

  * and directly get the byte array.

  */

 public class ExtendedByteArrayDataOutput extends ByteArrayOutputStream

     implements ExtendedDataOutput {

   /** Default number of bytes */

   private static final int DEFAULT_BYTES = 32;

   /** Internal data output */

   private final DataOutput dataOutput;

   /**

    * Uses the byte array provided or if null, use a default size

    *

    * @param buf Buffer to use

    */

   public ExtendedByteArrayDataOutput(byte[] buf) {

     if (buf == null) {

       this.buf = new byte[DEFAULT_BYTES];

     } else {

       this.buf = buf;

     }

     dataOutput = new DataOutputStream(this);

   }

   /**

    * Uses the byte array provided at the given pos

    *

    * @param buf Buffer to use

    * @param pos Position in the buffer to start writing from

    */

   public ExtendedByteArrayDataOutput(byte[] buf, int pos) {

     this(buf);

     this.count = pos;

   }

   /**

    * Creates a new byte array output stream. The buffer capacity is

    * initially 32 bytes, though its size increases if necessary.

    */

   public ExtendedByteArrayDataOutput() {

     this(DEFAULT_BYTES);

   }

   /**

    * Creates a new byte array output stream, with a buffer capacity of

    * the specified size, in bytes.

    *

    * @param size the initial size.

    * @exception  IllegalArgumentException if size is negative.

    */

   public ExtendedByteArrayDataOutput(int size) {

     if (size < 0) {

       throw new IllegalArgumentException("Negative initial size: " +

           size);

     }

     buf = new byte[size];

     dataOutput = new DataOutputStream(this);

   }

   @Override

   public void writeBoolean(boolean v) throws IOException {

     dataOutput.writeBoolean(v);

   }

   @Override

   public void writeByte(int v) throws IOException {

     dataOutput.writeByte(v);

   }

   @Override

   public void writeShort(int v) throws IOException {

     dataOutput.writeShort(v);

   }

   @Override

   public void writeChar(int v) throws IOException {

     dataOutput.writeChar(v);

   }

   @Override

   public void writeInt(int v) throws IOException {

     dataOutput.writeInt(v);

   }

   @Override

   public void writeLong(long v) throws IOException {

     dataOutput.writeLong(v);

   }

   @Override

   public void writeFloat(float v) throws IOException {

     dataOutput.writeFloat(v);

   }

   @Override

   public void writeDouble(double v) throws IOException {

     dataOutput.writeDouble(v);

   }

   @Override

   public void writeBytes(String s) throws IOException {

     dataOutput.writeBytes(s);

   }

   @Override

   public void writeChars(String s) throws IOException {

     dataOutput.writeChars(s);

   }

   @Override

   public void writeUTF(String s) throws IOException {

     dataOutput.writeUTF(s);

   }

   @Override

   public void ensureWritable(int minSize) {

     if ((count + minSize) > buf.length) {

       buf = Arrays.copyOf(buf, Math.max(buf.length << 1, count + minSize));

     }

   }

   @Override

   public void skipBytes(int bytesToSkip) {

     ensureWritable(bytesToSkip);

     count += bytesToSkip;

   }

   @Override

   public void writeInt(int position, int value) {

     if (position + 4 > count) {

       throw new IndexOutOfBoundsException(

           "writeIntOnPosition: Tried to write int to position " + position +

               " but current length is " + count);

     }

     buf[position] = (byte) ((value >>> 24) & 0xFF);

     buf[position + 1] = (byte) ((value >>> 16) & 0xFF);

     buf[position + 2] = (byte) ((value >>> 8) & 0xFF);

     buf[position + 3] = (byte) ((value >>> 0) & 0xFF);

   }

   @Override

   public byte[] toByteArray(int offset, int length) {

     if (offset + length > count) {

       throw new IndexOutOfBoundsException(String.format("Offset: %d + " +

           "Length: %d exceeds the size of buf : %d", offset, length, count));

     }

     return Arrays.copyOfRange(buf, offset, length);

   }

   @Override

   public byte[] getByteArray() {

     return buf;

   }

   @Override

   public int getPos() {

     return count;

   }

 }