/*
    * 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.handler.codec.marshalling;
  
  import io.netty.buffer.ByteBuf;
  import org.jboss.marshalling.ByteInput;
  
  import java.io.IOException;
  
  /**
   * {@link ByteInput} implementation which reads its data from a {@link ByteBuf}
   */
  class ChannelBufferByteInput implements ByteInput {
  
      private final ByteBuf buffer;
  
      ChannelBufferByteInput(ByteBuf buffer) {
          this.buffer = buffer;
      }
  
      @Override
      public void close() throws IOException {
          // nothing to do
      }
  
      @Override
      public int available() throws IOException {
          return buffer.readableBytes();
      }
  
      @Override
      public int read() throws IOException {
          if (buffer.isReadable()) {
              return buffer.readByte() & 0xff;
          }
          return -1;
      }
  
      @Override
      public int read(byte[] array) throws IOException {
          return read(array, 0, array.length);
      }
  
      @Override
      public int read(byte[] dst, int dstIndex, int length) throws IOException {
          int available = available();
          if (available == 0) {
              return -1;
          }
  
          length = Math.min(available, length);
          buffer.readBytes(dst, dstIndex, length);
          return length;
      }
  
      @Override
      public long skip(long bytes) throws IOException {
          int readable = buffer.readableBytes();
          if (readable < bytes) {
              bytes = readable;
          }
          buffer.readerIndex((int) (buffer.readerIndex() + bytes));
          return bytes;
      }
  
  }