/*
    * 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.Deflater;
  
  import org.jboss.netty.buffer.ChannelBuffer;
  
  class SpdyHeaderBlockZlibCompressor extends SpdyHeaderBlockCompressor {
  
      private final byte[] out = new byte[8192];
      private final Deflater compressor;
  
      public SpdyHeaderBlockZlibCompressor(int version, int compressionLevel) {
          if (version < SPDY_MIN_VERSION || version > SPDY_MAX_VERSION) {
              throw new IllegalArgumentException(
                      "unsupported version: " + version);
          }
          if (compressionLevel < 0 || compressionLevel > 9) {
              throw new IllegalArgumentException(
                      "compressionLevel: " + compressionLevel + " (expected: 0-9)");
          }
          compressor = new Deflater(compressionLevel);
          if (version < 3) {
              compressor.setDictionary(SPDY2_DICT);
          } else {
              compressor.setDictionary(SPDY_DICT);
          }
      }
  
      @Override
      public void setInput(ChannelBuffer decompressed) {
          byte[] in = new byte[decompressed.readableBytes()];
          decompressed.readBytes(in);
          compressor.setInput(in);
      }
  
      @Override
      public void encode(ChannelBuffer compressed) {
          int numBytes = out.length;
          while (numBytes == out.length) {
              numBytes = compressor.deflate(out, 0, out.length, Deflater.SYNC_FLUSH);
              compressed.writeBytes(out, 0, numBytes);
          }
      }
  
      @Override
      public void end() {
          compressor.end();
      }
  }