BitFlagsGenerator.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / WCF / Serialization / System / Runtime / Serialization / BitFlagsGenerator.cs / 1305376 / BitFlagsGenerator.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------

namespace System.Runtime.Serialization 
{
    using System; 
    using System.Reflection; 
    using System.Reflection.Emit;
    using System.Security; 

    [Fx.Tag.SecurityNote(Miscellaneous = "RequiresReview (Critical) - works on CodeGenerator objects, which require Critical access.")]
    class BitFlagsGenerator
    { 
        int bitCount;
        CodeGenerator ilg; 
        LocalBuilder[] locals; 

        public BitFlagsGenerator(int bitCount, CodeGenerator ilg, string localName) 
        {
            this.ilg = ilg;
            this.bitCount = bitCount;
            int localCount = (bitCount + 7) / 8; 
            locals = new LocalBuilder[localCount];
            for (int i = 0; i < locals.Length; i++) 
            { 
                locals[i] = ilg.DeclareLocal(typeof(byte), localName + i, (byte) 0);
            } 
        }

        public static bool IsBitSet(byte[] bytes, int bitIndex)
        { 
            int byteIndex = GetByteIndex(bitIndex);
            byte bitValue = GetBitValue(bitIndex); 
            return (bytes[byteIndex] & bitValue) == bitValue; 
        }
 
        public static void SetBit(byte[] bytes, int bitIndex)
        {
            int byteIndex = GetByteIndex(bitIndex);
            byte bitValue = GetBitValue(bitIndex); 
            bytes[byteIndex] |= bitValue;
        } 
 
        public int GetBitCount()
        { 
            return bitCount;
        }

        public LocalBuilder GetLocal(int i) 
        {
            return locals[i]; 
        } 

        public int GetLocalCount() 
        {
            return locals.Length;
        }
 
        public void Load(int bitIndex)
        { 
            LocalBuilder local = locals[GetByteIndex(bitIndex)]; 
            byte bitValue = GetBitValue(bitIndex);
            ilg.Load(local); 
            ilg.Load(bitValue);
            ilg.And();
            ilg.Load(bitValue);
            ilg.Ceq(); 
        }
 
        public void LoadArray() 
        {
            LocalBuilder localArray = ilg.DeclareLocal(Globals.TypeOfByteArray, "localArray"); 
            ilg.NewArray(typeof(byte), locals.Length);
            ilg.Store(localArray);
            for (int i = 0; i < locals.Length; i++)
            { 
                ilg.StoreArrayElement(localArray, i, locals[i]);
            } 
            ilg.Load(localArray); 
        }
 
        public void Store(int bitIndex, bool value)
        {
            LocalBuilder local = locals[GetByteIndex(bitIndex)];
            byte bitValue = GetBitValue(bitIndex); 
            if (value)
            { 
                ilg.Load(local); 
                ilg.Load(bitValue);
                ilg.Or(); 
                ilg.Stloc(local);
            }
            else
            { 
                ilg.Load(local);
                ilg.Load(bitValue); 
                ilg.Not(); 
                ilg.And();
                ilg.Stloc(local); 
            }
        }

        static byte GetBitValue(int bitIndex) 
        {
            return (byte)(1 << (bitIndex & 7)); 
        } 

        static int GetByteIndex(int bitIndex) 
        {
            return bitIndex >> 3;
        }
 
    }
} 
 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK