AlgoModule.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ Dotnetfx_Vista_SP2 / Dotnetfx_Vista_SP2 / 8.0.50727.4016 / DEVDIV / depot / DevDiv / releases / Orcas / QFE / wpf / src / Core / CSharp / MS / Internal / Ink / InkSerializedFormat / AlgoModule.cs / 1 / AlgoModule.cs

                            using MS.Utility; 
using System;
using System.Runtime.InteropServices;
using System.Security;
using System.Globalization; 
using System.Windows;
using System.Windows.Input; 
using System.Windows.Ink; 
using MS.Internal.Ink.InkSerializedFormat;
using System.Collections.Generic; 
using System.Diagnostics;

using SR = MS.Internal.PresentationCore.SR;
using SRID = MS.Internal.PresentationCore.SRID; 

namespace MS.Internal.Ink.InkSerializedFormat 
{ 
    internal class AlgoModule
    { 
        /// 
        /// Ctor
        /// 
        internal AlgoModule() 
        {
        } 
 
        /// 
        /// Based on the given input, finds the best compression to use on it. 
        /// 
        /// assumed to be point data (x,x,x,x,x,x,x)
        /// 
        internal byte GetBestDefHuff(int[] input) 
        {
            if (input.Length < 3) 
            { 
                return NoCompression;
            } 
            DeltaDelta xfDelDel = new DeltaDelta();
            int xfData = 0;
            int exData = 0;
 
            // Perform delta delta 2 times to set up the internal state of
            // delta delta transform 
            xfDelDel.Transform(input[0], ref xfData, ref exData); 
            xfDelDel.Transform(input[1], ref xfData, ref exData);
            double sumSq = 0.0; 

            // Compute the variance of the delta delta
            uint n = 2;
            for(; n < input.Length; n++) 
            {
                xfDelDel.Transform(input[n], ref xfData, ref exData); 
                if (0 == exData) 
                {
                    sumSq += ((double)xfData * (double)xfData); 
                }
            }
            sumSq *= (0.205625 / (n - 1.0));
 
            int i = DefaultFirstSquareRoot.Length - 2;
            for(; i > 1; i--) 
            { 
                if(sumSq > DefaultFirstSquareRoot[i])
                { 
                    break;
                }
            }
 
            byte retVal = (byte)(IndexedHuffman | (byte)(i + 1));
            return retVal; 
        } 

        ///  
        /// Compresses int[] packet data, returns it as a byte[]
        /// 
        /// assumed to be point data (x,x,x,x,x,x,x)
        /// magic byte specifying the compression to use 
        /// 
        internal byte[] CompressPacketData(int[] input, byte compression) 
        { 
            if (input == null)
            { 
                throw new ArgumentNullException("input");
            }

            List compressedData = new List(); 
            //leave room at the beginning of
            //compressedData for the compression header byte 
            //which we will add at the end 
            compressedData.Add((byte)0);
 
            if (DefaultCompression == (DefaultCompression & compression))
            {
                compression = GetBestDefHuff(input);
            } 
            if (IndexedHuffman == (DefaultCompression & compression))
            { 
                DataXform dtxf = this.HuffModule.FindDtXf(compression); 
                HuffCodec huffCodec = this.HuffModule.FindCodec(compression);
                huffCodec.Compress(dtxf, input, compressedData); 
                if (((compressedData.Count - 1/*for the algo byte we just made room for*/) >> 2) > input.Length)
                {
                    //recompress with no compression (gorilla)
                    compression = NoCompression; 
                    //reset
                    compressedData.Clear(); 
                    compressedData.Add((byte)0); 
                }
            } 
            if (NoCompression == (DefaultCompression & compression))
            {
                bool testDelDel = ((compression & 0x20) != 0);
                compression = 
                    this.GorillaCodec.FindPacketAlgoByte(input, testDelDel);
 
                DeltaDelta dtxf = null; 
                if ((compression & 0x20) != 0)
                { 
                    dtxf = this.DeltaDelta;
                }

                int inputIndex = 0; 
                if (null != dtxf)
                { 
                    //multibyteencode the first two values 
                    int xfData = 0;
                    int xfExtra = 0; 

                    dtxf.ResetState();
                    dtxf.Transform(input[0], ref xfData, ref xfExtra);
                    this.MultiByteCodec.SignEncode(xfData, compressedData); 

                    dtxf.Transform(input[1], ref xfData, ref xfExtra); 
                    this.MultiByteCodec.SignEncode(xfData, compressedData); 

                    //advance to the third member, we've already read the first two 
                    inputIndex = 2;
                }

                //Gorllia time 
                int bitCount = (compression & 0x1F);
                this.GorillaCodec.Compress( bitCount,           //the max count of bits required for each int 
                                            input,              //the input array to compress 
                                            inputIndex,         //the index to start compressing at
                                            dtxf,               //data transform to use when compressing, can be null 
                                            compressedData);    //a ref to the compressed data that will be written to
            }

            // compression / algo data always goes in index 0 
            compressedData[0] = compression;
            return compressedData.ToArray(); 
        } 

        ///  
        /// DecompressPacketData - given a compressed byte[], uncompress it to the outputBuffer
        /// 
        /// compressed byte from the ISF stream
        /// prealloc'd buffer to write to 
        /// 
        internal uint DecompressPacketData(byte[] input, int[] outputBuffer) 
        { 
            if (input == null)
            { 
                throw new ArgumentNullException("input");
            }
            if (input.Length < 2)
            { 
                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("Input buffer passed was shorter than expected"));
            } 
            if (outputBuffer == null) 
            {
                throw new ArgumentNullException("outputBuffer"); 
            }
            if (outputBuffer.Length == 0)
            {
                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("output buffer length was zero")); 
            }
 
            byte compression = input[0]; 
            uint totalBytesRead = 1; //we just read one
            int inputIndex = 1; 
            switch (compression & 0xC0)
            {
                case 0x80://IndexedHuffman
                    { 
                        DataXform dtxf = this.HuffModule.FindDtXf(compression);
                        HuffCodec huffCodec = this.HuffModule.FindCodec(compression); 
                        totalBytesRead += huffCodec.Uncompress(dtxf, input, inputIndex, outputBuffer); 
                        return totalBytesRead;
                    } 
                case 0x00: //NoCompression
                    {
                        int outputBufferIndex = 0;
                        DeltaDelta dtxf = null; 
                        if ((compression & 0x20) != 0)
                        { 
                            dtxf = this.DeltaDelta; 
                        }
 
                        int bitCount = 0;
                        if ((compression & 0x1F) == 0)
                        {
                            bitCount = Native.BitsPerInt;//32 
                        }
                        else 
                        { 
                            bitCount = (compression & 0x1F);
                        } 

                        if (null != dtxf)
                        {
                            //must have at least two more bytes besides the 
                            //initial algo byte
                            if (input.Length < 3) 
                            { 
                                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("Input buffer was too short (must be at least 3 bytes)"));
                            } 

                            //multibyteencode the first two values
                            int xfData = 0;
                            int xfExtra = 0; 

                            dtxf.ResetState(); 
 
                            uint bytesRead =
                                this.MultiByteCodec.SignDecode(input, inputIndex, ref xfData); 
                            //advance our index
                            inputIndex += (int)bytesRead;
                            totalBytesRead += bytesRead;
                            int result = dtxf.InverseTransform(xfData, xfExtra); 
                            Debug.Assert(outputBufferIndex < outputBuffer.Length);
                            outputBuffer[outputBufferIndex++] = result; 
 
                            bytesRead =
                                this.MultiByteCodec.SignDecode(input, inputIndex, ref xfData); 
                            //advance our index
                            inputIndex += (int)bytesRead;
                            totalBytesRead += bytesRead;
                            result = dtxf.InverseTransform(xfData, xfExtra); 
                            Debug.Assert(outputBufferIndex < outputBuffer.Length);
                            outputBuffer[outputBufferIndex++] = result; 
                        } 

                        totalBytesRead += 
                            this.GorillaCodec.Uncompress(  bitCount,    //the max count of bits required for each int
                                                           input,       //the input array to uncompress
                                                           inputIndex,  //the index to start uncompressing at
                                                           dtxf,        //data transform to use when compressing, can be null 
                                                           outputBuffer,//a ref to the output buffer to write to
                                                           outputBufferIndex); //the index of the output buffer to write to 
 
                        return totalBytesRead;
                    } 
                default:
                    {
                        throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("Invalid decompression algo byte"));
                    } 

            } 
        } 

        ///  
        /// Compresses property data which is already in the form of a byte[]
        /// into a compressed byte[]
        /// 
        /// byte[] data ready to be compressed 
        /// the compression to use
        ///  
        internal byte[] CompressPropertyData(byte[] input, byte compression) 
        {
            List compressedData = new List(input.Length + 1); //reasonable default based on profiling. 

            //leave room at the beginning of
            //compressedData for the compression header byte
            compressedData.Add((byte)0); 

            if (DefaultCompression == (DefaultCompression & compression)) 
            { 
                compression = this.GorillaCodec.FindPropAlgoByte(input);
            } 

            //validate that we never lzencode
            if (LempelZiv == (compression & LempelZiv))
            { 
                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("Invalid compression specified or computed by FindPropAlgoByte"));
            } 
 
            //determine what the optimal way to compress the data is.  Should we treat
            //the byte[] as a series of Int's, Short's or Byte's? 
            int countPerItem = 0, bitCount = 0, padCount = 0;
            this.GorillaCodec.GetPropertyBitCount(compression, ref countPerItem, ref bitCount, ref padCount);

            Debug.Assert(countPerItem == 4 || countPerItem == 2 || countPerItem == 1); 

            GorillaEncodingType type = GorillaEncodingType.Byte; 
            int unitCount = input.Length; 
            if (countPerItem == 4)
            { 
                type = GorillaEncodingType.Int;
                unitCount >>= 2;
            }
            else if (countPerItem == 2) 
            {
                type = GorillaEncodingType.Short; 
                unitCount >>= 1; 
            }
 

            BitStreamReader reader = new BitStreamReader(input);

            //encode, gorilla style 
            this.GorillaCodec.Compress(bitCount,            //the max count of bits required for each int
                                        reader,             //the reader, which can read int, byte, short 
                                        type,               //informs how the reader reads 
                                        unitCount,          //just how many items do we need to compress?
                                        compressedData);    //a ref to the compressed data that will be written to 

            compressedData[0] = compression;
            return compressedData.ToArray();
        } 

        ///  
        /// Decompresses property data (from a compressed byte[] to an uncompressed byte[]) 
        /// 
        /// The byte[] to decompress 
        /// 
        internal byte[] DecompressPropertyData(byte[] input)
        {
            if (input == null) 
            {
                throw new ArgumentNullException("input"); 
            } 
            if (input.Length < 2)
            { 
                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("input.Length must be at least 2"));
            }

            byte compression = input[0]; 
            int inputIndex = 1;
 
            if (LempelZiv == (compression & LempelZiv)) 
            {
                if (0 != (compression & (~LempelZiv))) 
                {
                    throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("bogus isf, we don't decompress property data with lz"));
                }
                return this.LZCodec.Uncompress(input, inputIndex); 
            }
            else 
            { 
                //gorilla
 
                //determine what the way to uncompress the data.  Should we treat
                //the byte[] as a series of Int's, Short's or Byte's?
                int countPerItem = 0, bitCount = 0, padCount = 0;
                this.GorillaCodec.GetPropertyBitCount(compression, ref countPerItem, ref bitCount, ref padCount); 
                Debug.Assert(countPerItem == 4 || countPerItem == 2 || countPerItem == 1);
 
                GorillaEncodingType type = GorillaEncodingType.Byte; 
                if (countPerItem == 4)
                { 
                    type = GorillaEncodingType.Int;
                }
                else if (countPerItem == 2)
                { 
                    type = GorillaEncodingType.Short;
                } 
 
                //determine how many units (of int, short or byte) that there are to decompress
                int unitsToDecode = ((input.Length - inputIndex << 3) / bitCount) - padCount; 
                BitStreamReader reader = new BitStreamReader(input, inputIndex);
                return this.GorillaCodec.Uncompress(bitCount, reader, type, unitsToDecode);
            }
 
        }
 
        ///  
        /// Private lazy init'd member
        ///  
        private HuffModule HuffModule
        {
            get
            { 
                if (_huffModule == null)
                { 
                    _huffModule = new HuffModule(); 
                }
                return _huffModule; 
            }
        }

        ///  
        /// Private lazy init'd member
        ///  
        private MultiByteCodec MultiByteCodec 
        {
            get 
            {
                if (_multiByteCodec == null)
                {
                    _multiByteCodec = new MultiByteCodec(); 
                }
                return _multiByteCodec; 
            } 
        }
 
        /// 
        /// Private lazy init'd member
        /// 
        private DeltaDelta DeltaDelta 
        {
            get 
            { 
                if (_deltaDelta == null)
                { 
                    _deltaDelta = new DeltaDelta();
                }
                return _deltaDelta;
            } 
        }
 
        ///  
        /// Private lazy init'd member
        ///  
        private GorillaCodec GorillaCodec
        {
            get
            { 
                if (_gorillaCodec == null)
                { 
                    _gorillaCodec = new GorillaCodec(); 
                }
                return _gorillaCodec; 
            }
        }

        ///  
        /// Private lazy init'd member
        ///  
        private LZCodec LZCodec 
        {
            get 
            {
                if (_lzCodec == null)
                {
                    _lzCodec = new LZCodec(); 
                }
                return _lzCodec; 
            } 
        }
 
        /// 
        /// Privates, lazy initialized, do not reference directly
        /// 
        private HuffModule          _huffModule; 
        private MultiByteCodec      _multiByteCodec;
        private DeltaDelta          _deltaDelta; 
        private GorillaCodec        _gorillaCodec; 
        private LZCodec             _lzCodec;
 
        /// 
        /// Static members defined in Penimc code
        /// 
        internal static readonly byte NoCompression = 0x00; 
        internal static readonly byte DefaultCompression = 0xC0;
        internal static readonly byte IndexedHuffman = 0x80; 
        internal static readonly byte LempelZiv = 0x80; 
        internal static readonly byte DefaultBAACount = 8;
        internal static readonly byte MaxBAACount = 10; 


        private static readonly double[] DefaultFirstSquareRoot = { 1, 1, 1, 4, 9, 16, 36, 49};
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
using MS.Utility; 
using System;
using System.Runtime.InteropServices;
using System.Security;
using System.Globalization; 
using System.Windows;
using System.Windows.Input; 
using System.Windows.Ink; 
using MS.Internal.Ink.InkSerializedFormat;
using System.Collections.Generic; 
using System.Diagnostics;

using SR = MS.Internal.PresentationCore.SR;
using SRID = MS.Internal.PresentationCore.SRID; 

namespace MS.Internal.Ink.InkSerializedFormat 
{ 
    internal class AlgoModule
    { 
        /// 
        /// Ctor
        /// 
        internal AlgoModule() 
        {
        } 
 
        /// 
        /// Based on the given input, finds the best compression to use on it. 
        /// 
        /// assumed to be point data (x,x,x,x,x,x,x)
        /// 
        internal byte GetBestDefHuff(int[] input) 
        {
            if (input.Length < 3) 
            { 
                return NoCompression;
            } 
            DeltaDelta xfDelDel = new DeltaDelta();
            int xfData = 0;
            int exData = 0;
 
            // Perform delta delta 2 times to set up the internal state of
            // delta delta transform 
            xfDelDel.Transform(input[0], ref xfData, ref exData); 
            xfDelDel.Transform(input[1], ref xfData, ref exData);
            double sumSq = 0.0; 

            // Compute the variance of the delta delta
            uint n = 2;
            for(; n < input.Length; n++) 
            {
                xfDelDel.Transform(input[n], ref xfData, ref exData); 
                if (0 == exData) 
                {
                    sumSq += ((double)xfData * (double)xfData); 
                }
            }
            sumSq *= (0.205625 / (n - 1.0));
 
            int i = DefaultFirstSquareRoot.Length - 2;
            for(; i > 1; i--) 
            { 
                if(sumSq > DefaultFirstSquareRoot[i])
                { 
                    break;
                }
            }
 
            byte retVal = (byte)(IndexedHuffman | (byte)(i + 1));
            return retVal; 
        } 

        ///  
        /// Compresses int[] packet data, returns it as a byte[]
        /// 
        /// assumed to be point data (x,x,x,x,x,x,x)
        /// magic byte specifying the compression to use 
        /// 
        internal byte[] CompressPacketData(int[] input, byte compression) 
        { 
            if (input == null)
            { 
                throw new ArgumentNullException("input");
            }

            List compressedData = new List(); 
            //leave room at the beginning of
            //compressedData for the compression header byte 
            //which we will add at the end 
            compressedData.Add((byte)0);
 
            if (DefaultCompression == (DefaultCompression & compression))
            {
                compression = GetBestDefHuff(input);
            } 
            if (IndexedHuffman == (DefaultCompression & compression))
            { 
                DataXform dtxf = this.HuffModule.FindDtXf(compression); 
                HuffCodec huffCodec = this.HuffModule.FindCodec(compression);
                huffCodec.Compress(dtxf, input, compressedData); 
                if (((compressedData.Count - 1/*for the algo byte we just made room for*/) >> 2) > input.Length)
                {
                    //recompress with no compression (gorilla)
                    compression = NoCompression; 
                    //reset
                    compressedData.Clear(); 
                    compressedData.Add((byte)0); 
                }
            } 
            if (NoCompression == (DefaultCompression & compression))
            {
                bool testDelDel = ((compression & 0x20) != 0);
                compression = 
                    this.GorillaCodec.FindPacketAlgoByte(input, testDelDel);
 
                DeltaDelta dtxf = null; 
                if ((compression & 0x20) != 0)
                { 
                    dtxf = this.DeltaDelta;
                }

                int inputIndex = 0; 
                if (null != dtxf)
                { 
                    //multibyteencode the first two values 
                    int xfData = 0;
                    int xfExtra = 0; 

                    dtxf.ResetState();
                    dtxf.Transform(input[0], ref xfData, ref xfExtra);
                    this.MultiByteCodec.SignEncode(xfData, compressedData); 

                    dtxf.Transform(input[1], ref xfData, ref xfExtra); 
                    this.MultiByteCodec.SignEncode(xfData, compressedData); 

                    //advance to the third member, we've already read the first two 
                    inputIndex = 2;
                }

                //Gorllia time 
                int bitCount = (compression & 0x1F);
                this.GorillaCodec.Compress( bitCount,           //the max count of bits required for each int 
                                            input,              //the input array to compress 
                                            inputIndex,         //the index to start compressing at
                                            dtxf,               //data transform to use when compressing, can be null 
                                            compressedData);    //a ref to the compressed data that will be written to
            }

            // compression / algo data always goes in index 0 
            compressedData[0] = compression;
            return compressedData.ToArray(); 
        } 

        ///  
        /// DecompressPacketData - given a compressed byte[], uncompress it to the outputBuffer
        /// 
        /// compressed byte from the ISF stream
        /// prealloc'd buffer to write to 
        /// 
        internal uint DecompressPacketData(byte[] input, int[] outputBuffer) 
        { 
            if (input == null)
            { 
                throw new ArgumentNullException("input");
            }
            if (input.Length < 2)
            { 
                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("Input buffer passed was shorter than expected"));
            } 
            if (outputBuffer == null) 
            {
                throw new ArgumentNullException("outputBuffer"); 
            }
            if (outputBuffer.Length == 0)
            {
                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("output buffer length was zero")); 
            }
 
            byte compression = input[0]; 
            uint totalBytesRead = 1; //we just read one
            int inputIndex = 1; 
            switch (compression & 0xC0)
            {
                case 0x80://IndexedHuffman
                    { 
                        DataXform dtxf = this.HuffModule.FindDtXf(compression);
                        HuffCodec huffCodec = this.HuffModule.FindCodec(compression); 
                        totalBytesRead += huffCodec.Uncompress(dtxf, input, inputIndex, outputBuffer); 
                        return totalBytesRead;
                    } 
                case 0x00: //NoCompression
                    {
                        int outputBufferIndex = 0;
                        DeltaDelta dtxf = null; 
                        if ((compression & 0x20) != 0)
                        { 
                            dtxf = this.DeltaDelta; 
                        }
 
                        int bitCount = 0;
                        if ((compression & 0x1F) == 0)
                        {
                            bitCount = Native.BitsPerInt;//32 
                        }
                        else 
                        { 
                            bitCount = (compression & 0x1F);
                        } 

                        if (null != dtxf)
                        {
                            //must have at least two more bytes besides the 
                            //initial algo byte
                            if (input.Length < 3) 
                            { 
                                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("Input buffer was too short (must be at least 3 bytes)"));
                            } 

                            //multibyteencode the first two values
                            int xfData = 0;
                            int xfExtra = 0; 

                            dtxf.ResetState(); 
 
                            uint bytesRead =
                                this.MultiByteCodec.SignDecode(input, inputIndex, ref xfData); 
                            //advance our index
                            inputIndex += (int)bytesRead;
                            totalBytesRead += bytesRead;
                            int result = dtxf.InverseTransform(xfData, xfExtra); 
                            Debug.Assert(outputBufferIndex < outputBuffer.Length);
                            outputBuffer[outputBufferIndex++] = result; 
 
                            bytesRead =
                                this.MultiByteCodec.SignDecode(input, inputIndex, ref xfData); 
                            //advance our index
                            inputIndex += (int)bytesRead;
                            totalBytesRead += bytesRead;
                            result = dtxf.InverseTransform(xfData, xfExtra); 
                            Debug.Assert(outputBufferIndex < outputBuffer.Length);
                            outputBuffer[outputBufferIndex++] = result; 
                        } 

                        totalBytesRead += 
                            this.GorillaCodec.Uncompress(  bitCount,    //the max count of bits required for each int
                                                           input,       //the input array to uncompress
                                                           inputIndex,  //the index to start uncompressing at
                                                           dtxf,        //data transform to use when compressing, can be null 
                                                           outputBuffer,//a ref to the output buffer to write to
                                                           outputBufferIndex); //the index of the output buffer to write to 
 
                        return totalBytesRead;
                    } 
                default:
                    {
                        throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("Invalid decompression algo byte"));
                    } 

            } 
        } 

        ///  
        /// Compresses property data which is already in the form of a byte[]
        /// into a compressed byte[]
        /// 
        /// byte[] data ready to be compressed 
        /// the compression to use
        ///  
        internal byte[] CompressPropertyData(byte[] input, byte compression) 
        {
            List compressedData = new List(input.Length + 1); //reasonable default based on profiling. 

            //leave room at the beginning of
            //compressedData for the compression header byte
            compressedData.Add((byte)0); 

            if (DefaultCompression == (DefaultCompression & compression)) 
            { 
                compression = this.GorillaCodec.FindPropAlgoByte(input);
            } 

            //validate that we never lzencode
            if (LempelZiv == (compression & LempelZiv))
            { 
                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("Invalid compression specified or computed by FindPropAlgoByte"));
            } 
 
            //determine what the optimal way to compress the data is.  Should we treat
            //the byte[] as a series of Int's, Short's or Byte's? 
            int countPerItem = 0, bitCount = 0, padCount = 0;
            this.GorillaCodec.GetPropertyBitCount(compression, ref countPerItem, ref bitCount, ref padCount);

            Debug.Assert(countPerItem == 4 || countPerItem == 2 || countPerItem == 1); 

            GorillaEncodingType type = GorillaEncodingType.Byte; 
            int unitCount = input.Length; 
            if (countPerItem == 4)
            { 
                type = GorillaEncodingType.Int;
                unitCount >>= 2;
            }
            else if (countPerItem == 2) 
            {
                type = GorillaEncodingType.Short; 
                unitCount >>= 1; 
            }
 

            BitStreamReader reader = new BitStreamReader(input);

            //encode, gorilla style 
            this.GorillaCodec.Compress(bitCount,            //the max count of bits required for each int
                                        reader,             //the reader, which can read int, byte, short 
                                        type,               //informs how the reader reads 
                                        unitCount,          //just how many items do we need to compress?
                                        compressedData);    //a ref to the compressed data that will be written to 

            compressedData[0] = compression;
            return compressedData.ToArray();
        } 

        ///  
        /// Decompresses property data (from a compressed byte[] to an uncompressed byte[]) 
        /// 
        /// The byte[] to decompress 
        /// 
        internal byte[] DecompressPropertyData(byte[] input)
        {
            if (input == null) 
            {
                throw new ArgumentNullException("input"); 
            } 
            if (input.Length < 2)
            { 
                throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("input.Length must be at least 2"));
            }

            byte compression = input[0]; 
            int inputIndex = 1;
 
            if (LempelZiv == (compression & LempelZiv)) 
            {
                if (0 != (compression & (~LempelZiv))) 
                {
                    throw new ArgumentException(StrokeCollectionSerializer.ISFDebugMessage("bogus isf, we don't decompress property data with lz"));
                }
                return this.LZCodec.Uncompress(input, inputIndex); 
            }
            else 
            { 
                //gorilla
 
                //determine what the way to uncompress the data.  Should we treat
                //the byte[] as a series of Int's, Short's or Byte's?
                int countPerItem = 0, bitCount = 0, padCount = 0;
                this.GorillaCodec.GetPropertyBitCount(compression, ref countPerItem, ref bitCount, ref padCount); 
                Debug.Assert(countPerItem == 4 || countPerItem == 2 || countPerItem == 1);
 
                GorillaEncodingType type = GorillaEncodingType.Byte; 
                if (countPerItem == 4)
                { 
                    type = GorillaEncodingType.Int;
                }
                else if (countPerItem == 2)
                { 
                    type = GorillaEncodingType.Short;
                } 
 
                //determine how many units (of int, short or byte) that there are to decompress
                int unitsToDecode = ((input.Length - inputIndex << 3) / bitCount) - padCount; 
                BitStreamReader reader = new BitStreamReader(input, inputIndex);
                return this.GorillaCodec.Uncompress(bitCount, reader, type, unitsToDecode);
            }
 
        }
 
        ///  
        /// Private lazy init'd member
        ///  
        private HuffModule HuffModule
        {
            get
            { 
                if (_huffModule == null)
                { 
                    _huffModule = new HuffModule(); 
                }
                return _huffModule; 
            }
        }

        ///  
        /// Private lazy init'd member
        ///  
        private MultiByteCodec MultiByteCodec 
        {
            get 
            {
                if (_multiByteCodec == null)
                {
                    _multiByteCodec = new MultiByteCodec(); 
                }
                return _multiByteCodec; 
            } 
        }
 
        /// 
        /// Private lazy init'd member
        /// 
        private DeltaDelta DeltaDelta 
        {
            get 
            { 
                if (_deltaDelta == null)
                { 
                    _deltaDelta = new DeltaDelta();
                }
                return _deltaDelta;
            } 
        }
 
        ///  
        /// Private lazy init'd member
        ///  
        private GorillaCodec GorillaCodec
        {
            get
            { 
                if (_gorillaCodec == null)
                { 
                    _gorillaCodec = new GorillaCodec(); 
                }
                return _gorillaCodec; 
            }
        }

        ///  
        /// Private lazy init'd member
        ///  
        private LZCodec LZCodec 
        {
            get 
            {
                if (_lzCodec == null)
                {
                    _lzCodec = new LZCodec(); 
                }
                return _lzCodec; 
            } 
        }
 
        /// 
        /// Privates, lazy initialized, do not reference directly
        /// 
        private HuffModule          _huffModule; 
        private MultiByteCodec      _multiByteCodec;
        private DeltaDelta          _deltaDelta; 
        private GorillaCodec        _gorillaCodec; 
        private LZCodec             _lzCodec;
 
        /// 
        /// Static members defined in Penimc code
        /// 
        internal static readonly byte NoCompression = 0x00; 
        internal static readonly byte DefaultCompression = 0xC0;
        internal static readonly byte IndexedHuffman = 0x80; 
        internal static readonly byte LempelZiv = 0x80; 
        internal static readonly byte DefaultBAACount = 8;
        internal static readonly byte MaxBAACount = 10; 


        private static readonly double[] DefaultFirstSquareRoot = { 1, 1, 1, 4, 9, 16, 36, 49};
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
                        

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