/source/library/Interlace/Erlang/TermWriter.cs

#region Using Directives and Copyright Notice



// Copyright (c) 2007-2010, Computer Consultancy Pty Ltd

// All rights reserved.

// 

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are met:

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above copyright

//       notice, this list of conditions and the following disclaimer in the

//       documentation and/or other materials provided with the distribution.

//     * Neither the name of the Computer Consultancy Pty Ltd nor the

//       names of its contributors may be used to endorse or promote products

//       derived from this software without specific prior written permission.

// 

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 

// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 

// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 

// ARE DISCLAIMED. IN NO EVENT SHALL COMPUTER CONSULTANCY PTY LTD BE LIABLE 

// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 

// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 

// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 

// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 

// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 

// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH

// DAMAGE.



#endregion



// Portions of this code were originally developed for Bit Plantation BitLibrary.

// (Portions Copyright © 2006 Bit Plantation)



using System;

using System.Collections;

using System.Collections.Generic;

using System.Text;

using System.IO;

using System.Net;



namespace Interlace.Erlang

{

    public class TermWriter : IDisposable

    {

        BinaryWriter _writer;



        public TermWriter(Stream stream)

        {

            _writer = new BinaryWriter(stream);

        }



        public void Close()

        {

            _writer.Close();

        }



        public void Dispose()

        {

            Close();

        }



        public static byte[] TermToBinary(object term)

        {

            MemoryStream stream = new MemoryStream();



            using (TermWriter writer = new TermWriter(stream))

            {

                writer.WriteTerm(term);



                return stream.ToArray();

            }

        }



        void WriteByte(byte value)

        {

            _writer.Write(value);

        }



        void WriteUnsignedShort(ushort value)

        {

            _writer.Write((ushort)IPAddress.HostToNetworkOrder((short)value));

        }



        void WriteUnsignedInteger(uint value)

        {

            _writer.Write((uint)IPAddress.HostToNetworkOrder((int)value));

        }



        public void WriteTerm(object term)

        {

            _writer.Write((byte)Tags.Version);



            WriteObject(term);



            _writer.Flush();

        }



        void WriteObject(object obj)

        {

            if (obj is ITermWritable)

            {

                ITermWritable writable = obj as ITermWritable;



                object substitutedObject = writable.SerializeToTerms();

                WriteObject(substitutedObject);

                return;

            }



            if (obj is Atom)

            {

                WriteAtom(obj as Atom);

                return;

            }



            if (obj is Tuple)

            {

                WriteTuple(obj as Tuple);

                return;

            }



            if (obj is int || obj is short)

            {

                WriteIntegerTerm((int)Convert.ToInt32(obj));

                return;

            }



            if (obj is uint || obj is ushort || obj is byte)

            {

                WriteIntegerTerm((int)Convert.ToUInt32(obj));

                return;

            }



            if (obj is string)

            {

                WriteString(obj as string);

                return;

            }

            

            if (obj is bool)

            {

                WriteObject((bool)obj ? Atom.From("true") : Atom.From("false"));

                return;

            }



            if (obj is byte[])

            {

                WriteBinary(obj as byte[]);

                return;

            }



            if (obj is ICollection)

            {

                WriteList(obj as ICollection);

                return;

            }



            if (obj is ErlangProcessId)

            {

                WriteProcessId(obj as ErlangProcessId);

                return;

            }



            throw new ErlangProtocolException(string.Format(

                "An object of an unsupported type ({0}) was serialized.", obj.GetType().FullName));



        }



        void WriteIntegerTerm(int integer)

        {

            if (0 <= integer && integer <= 255)

            {

                WriteByte(Tags.SmallInteger);

                WriteByte((byte)integer);

            }

            else

            {

                WriteByte(Tags.Integer);

                WriteUnsignedInteger((uint)integer);

            }

        }



        void WriteTuple(Tuple tuple)

        {

            if (tuple.Length < 256)

            {

                WriteByte(Tags.SmallTuple);

                WriteByte((byte)tuple.Length);

            }

            else

            {

                WriteByte(Tags.LargeTuple);

                WriteUnsignedInteger((uint)tuple.Length);

            }



            for (int i = 0; i < tuple.Length; i++)

            {

                WriteObject(tuple[i]);

            }

        }



        void WriteBinary(byte[] binary)

        {

            WriteByte(Tags.Binary);



            WriteUnsignedInteger((uint)binary.Length);

            _writer.Write(binary);

        }



        void WriteList(ICollection list)

        {

            if (list.Count > 0)

            {

                WriteByte(Tags.List);



                WriteUnsignedInteger((uint)list.Count);



                foreach (object element in list)

                {

                    WriteObject(element);

                }



                WriteByte(Tags.Nil);

            }

            else

            {

                WriteByte(Tags.Nil);

            }

        }



        void WriteAtom(Atom atom)

        {

            WriteByte(Tags.Atom);



            byte[] symbolBytes = Encoding.ASCII.GetBytes(atom.Value);



            WriteUnsignedShort((ushort)symbolBytes.Length);

            _writer.Write(symbolBytes);

        }



        void WriteString(string stringValue)

        {

            WriteByte(Tags.String);



            byte[] stringBytes = Encoding.ASCII.GetBytes(stringValue);

            WriteUnsignedShort((ushort)stringBytes.Length);

            _writer.Write(stringBytes);

        }



        void WriteProcessId(ErlangProcessId processId)

        {

            WriteByte(Tags.ProcessId);



            WriteAtom(processId.Node);

            WriteUnsignedInteger(processId.Id);

            WriteUnsignedInteger(processId.Serial);

            WriteByte(processId.Creation);

        }

    }

}