/*
    * 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.spdy;
  
  import static org.jboss.netty.handler.codec.spdy.SpdyCodecUtil.*;
  
  import java.util.zip.DataFormatException;
  import java.util.zip.Inflater;
  
  import org.jboss.netty.buffer.ChannelBuffer;
  
  class SpdyHeaderBlockZlibDecompressor extends SpdyHeaderBlockDecompressor {
  
      private final int version;
      private final byte[] out = new byte[8192];
      private final Inflater decompressor = new Inflater();
  
      public SpdyHeaderBlockZlibDecompressor(int version) {
          if (version < SPDY_MIN_VERSION || version > SPDY_MAX_VERSION) {
              throw new IllegalArgumentException(
                      "unsupported version: " + version);
          }
          this.version = version;
      }
  
      @Override
      public void setInput(ChannelBuffer compressed) {
          byte[] in = new byte[compressed.readableBytes()];
          compressed.readBytes(in);
          decompressor.setInput(in);
      }
  
      @Override
      public int decode(ChannelBuffer decompressed) throws Exception {
          try {
              int numBytes = decompressor.inflate(out);
              if (numBytes == 0 && decompressor.needsDictionary()) {
                  if (version < 3) {
                      decompressor.setDictionary(SPDY2_DICT);
                  } else {
                      decompressor.setDictionary(SPDY_DICT);
                  }
                  numBytes = decompressor.inflate(out);
              }
              decompressed.writeBytes(out, 0, numBytes);
              return numBytes;
          } catch (DataFormatException e) {
              throw new SpdyProtocolException(
                      "Received invalid header block", e);
          }
      }
  
      @Override
      public void end() {
          decompressor.end();
      }
  }