Subversion Repositories SmartDukaan

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF 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.
 */

using System.IO;

namespace Thrift.Transport
{
        public class TFramedTransport : TTransport
        {
                protected TTransport transport = null;
                protected MemoryStream writeBuffer = new MemoryStream(1024);
                protected MemoryStream readBuffer = null;

                public class Factory : TTransportFactory
                {
                        public override TTransport GetTransport(TTransport trans)
                        {
                                return new TFramedTransport(trans);
                        }
                }

                public TFramedTransport(TTransport transport)
                {
                        this.transport = transport;
                }

                public override void Open()
                {
                        transport.Open();
                }

                public override bool IsOpen
                {
                        get
                        {
                                return transport.IsOpen;
                        }
                }

                public override void Close()
                {
                        transport.Close();
                }

                public override int Read(byte[] buf, int off, int len)
                {
                        if (readBuffer != null)
                        {
                                int got = readBuffer.Read(buf, off, len);
                                if (got > 0)
                                {
                                        return got;
                                }
                        }

                        // Read another frame of data
                        ReadFrame();

                        return readBuffer.Read(buf, off, len);
                }

                private void ReadFrame()
                {
                        byte[] i32rd = new byte[4];
                        transport.ReadAll(i32rd, 0, 4);
                        int size =
                                ((i32rd[0] & 0xff) << 24) |
                                ((i32rd[1] & 0xff) << 16) |
                                ((i32rd[2] & 0xff) <<  8) |
                                ((i32rd[3] & 0xff));

                        byte[] buff = new byte[size];
                        transport.ReadAll(buff, 0, size);
                        readBuffer = new MemoryStream(buff);
                }

                public override void Write(byte[] buf, int off, int len)
                {
                        writeBuffer.Write(buf, off, len);
                }

                public override void Flush()
                {
                        byte[] buf = writeBuffer.GetBuffer();
                        int len = (int)writeBuffer.Length;
                        writeBuffer = new MemoryStream(writeBuffer.Capacity);

                        byte[] i32out = new byte[4];
                        i32out[0] = (byte)(0xff & (len >> 24));
                        i32out[1] = (byte)(0xff & (len >> 16));
                        i32out[2] = (byte)(0xff & (len >> 8));
                        i32out[3] = (byte)(0xff & (len));
                        transport.Write(i32out, 0, 4);
                        transport.Write(buf, 0, len);
                        transport.Flush();
                }
        }
}