/*
    * Copyright (c) 2012 the original author or authors.
    *
    * Licensed 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.eclipse.jetty.spdy.generator;
  
  import java.nio.ByteBuffer;
  
  import org.eclipse.jetty.spdy.ByteBufferPool;
  import org.eclipse.jetty.spdy.api.DataInfo;
  import org.eclipse.jetty.spdy.frames.DataFrame;
  
  public class DataFrameGenerator
  {
      private final ByteBufferPool bufferPool;
  
      public DataFrameGenerator(ByteBufferPool bufferPool)
      {
          this.bufferPool = bufferPool;
      }
  
      public ByteBuffer generate(int streamId, int length, DataInfo dataInfo)
      {
          ByteBuffer buffer = bufferPool.acquire(DataFrame.HEADER_LENGTH + length, true);
          buffer.position(DataFrame.HEADER_LENGTH);
          // Guaranteed to always be >= 0
          int read = dataInfo.readInto(buffer);
  
          buffer.putInt(0, streamId & 0x7F_FF_FF_FF);
          buffer.putInt(4, read & 0x00_FF_FF_FF);
  
          byte flags = dataInfo.getFlags();
          if (dataInfo.available() > 0)
              flags &= ~DataInfo.FLAG_CLOSE;
          buffer.put(4, flags);
  
          buffer.flip();
          return buffer;
      }
  }