/*
    * 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 org.jboss.netty.handler.codec.serialization;
  
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.io.ObjectOutput;
  import java.io.ObjectOutputStream;
  import java.io.OutputStream;
  
  import org.jboss.netty.buffer.ChannelBuffer;
  import org.jboss.netty.buffer.ChannelBufferOutputStream;
  import org.jboss.netty.buffer.ChannelBuffers;
  
  /**
   * An {@link ObjectOutput} which is interoperable with {@link ObjectDecoder}
   * and {@link ObjectDecoderInputStream}.
   */
  public class ObjectEncoderOutputStream extends OutputStream implements
          ObjectOutput {
  
      private final DataOutputStream out;
      private final int estimatedLength;
  
      /**
       * Creates a new {@link ObjectOutput} with the estimated length of 512
       * bytes.
       *
       * @param out
       *        the {@link OutputStream} where the serialized form will be
       *        written out
       */
      public ObjectEncoderOutputStream(OutputStream out) {
          this(out, 512);
      }
  
      /**
       * Creates a new {@link ObjectOutput}.
       *
       * @param out
       *        the {@link OutputStream} where the serialized form will be
       *        written out
       *
       * @param estimatedLength
       *        the estimated byte length of the serialized form of an object.
       *        If the length of the serialized form exceeds this value, the
       *        internal buffer will be expanded automatically at the cost of
       *        memory bandwidth.  If this value is too big, it will also waste
       *        memory bandwidth.  To avoid unnecessary memory copy or allocation
       *        cost, please specify the properly estimated value.
       */
      public ObjectEncoderOutputStream(OutputStream out, int estimatedLength) {
          if (out == null) {
              throw new NullPointerException("out");
          }
          if (estimatedLength < 0) {
              throw new IllegalArgumentException("estimatedLength: " + estimatedLength);
          }
  
          if (out instanceof DataOutputStream) {
              this.out = (DataOutputStream) out;
          } else {
              this.out = new DataOutputStream(out);
          }
          this.estimatedLength = estimatedLength;
      }
  
      public void writeObject(Object obj) throws IOException {
          ChannelBufferOutputStream bout = new ChannelBufferOutputStream(
                  ChannelBuffers.dynamicBuffer(estimatedLength));
          ObjectOutputStream oout = new CompactObjectOutputStream(bout);
          oout.writeObject(obj);
          oout.flush();
          oout.close();
  
          ChannelBuffer buffer = bout.buffer();
          int objectSize = buffer.readableBytes();
          writeInt(objectSize);
          buffer.getBytes(0, this, objectSize);
      }
  
      @Override
      public void write(int b) throws IOException {
          out.write(b);
      }
  
     @Override
     public void close() throws IOException {
         out.close();
     }
 
     @Override
     public void flush() throws IOException {
         out.flush();
     }
 
     public final int size() {
         return out.size();
     }
 
     @Override
     public void write(byte[] b, int off, int len) throws IOException {
         out.write(b, off, len);
     }
 
     @Override
     public void write(byte[] b) throws IOException {
         out.write(b);
     }
 
     public final void writeBoolean(boolean v) throws IOException {
         out.writeBoolean(v);
     }
 
     public final void writeByte(int v) throws IOException {
         out.writeByte(v);
     }
 
     public final void writeBytes(String s) throws IOException {
         out.writeBytes(s);
     }
 
     public final void writeChar(int v) throws IOException {
         out.writeChar(v);
     }
 
     public final void writeChars(String s) throws IOException {
         out.writeChars(s);
     }
 
     public final void writeDouble(double v) throws IOException {
         out.writeDouble(v);
     }
 
     public final void writeFloat(float v) throws IOException {
         out.writeFloat(v);
     }
 
     public final void writeInt(int v) throws IOException {
         out.writeInt(v);
     }
 
     public final void writeLong(long v) throws IOException {
         out.writeLong(v);
     }
 
     public final void writeShort(int v) throws IOException {
         out.writeShort(v);
     }
 
     public final void writeUTF(String str) throws IOException {
         out.writeUTF(str);
     }
 }