MetadataAssemblyHelper.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 / fx / src / DataEntity / System / Data / Metadata / ObjectLayer / MetadataAssemblyHelper.cs / 1305376 / MetadataAssemblyHelper.cs
                        

                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner       [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System.Reflection; 
using System.Collections.Generic;
using System.Diagnostics;
using System.Data.Common.Utils;
 
namespace System.Data.Metadata.Edm
{ 
    internal static class MetadataAssemblyHelper 
    {
        static byte [] EcmaPublicKeyToken = System.Data.EntityModel.SchemaObjectModel.ScalarType.ConvertToByteArray(AssemblyRef.EcmaPublicKey); 
        static byte [] MsPublicKeyToken = System.Data.EntityModel.SchemaObjectModel.ScalarType.ConvertToByteArray(AssemblyRef.MicrosoftPublicKey);
        private static Memoizer _filterAssemblyCacheByAssembly = new Memoizer(MetadataAssemblyHelper.ComputeShouldFilterAssembly, EqualityComparer.Default);

        internal static Assembly SafeLoadReferencedAssembly(AssemblyName assemblyName) 
        {
            Assembly assembly = null; 
 
            try
            { 
                assembly = Assembly.Load(assemblyName);
            }
            catch (System.IO.FileNotFoundException)
            { 
                // See 552932: ObjectItemCollection: fails on referenced assemblies that are not available
            } 
 
            return assembly;
        } 

        private static bool ComputeShouldFilterAssembly(Assembly assembly)
        {
            AssemblyName assemblyName = new AssemblyName(assembly.FullName); 
            return ShouldFilterAssembly(assemblyName);
        } 
 
        internal static bool ShouldFilterAssembly(Assembly assembly)
        { 
            return _filterAssemblyCacheByAssembly.Evaluate(assembly);
        }

        /// Is the assembly and its referened assemblies not expected to have any metadata 
        private static bool ShouldFilterAssembly(AssemblyName assemblyName)
        { 
            return (ArePublicKeyTokensEqual(assemblyName.GetPublicKeyToken(), EcmaPublicKeyToken) || 
                    ArePublicKeyTokensEqual(assemblyName.GetPublicKeyToken(), MsPublicKeyToken));
        } 

        private static bool ArePublicKeyTokensEqual(byte [] left, byte [] right)
        {
            // some assemblies don't have public keys 
            if (left.Length != right.Length)
            { 
                return false; 
            }
 
            for (int i = 0; i < left.Length; i++)
            {
                if (left[i] != right[i])
                { 
                    return false;
                } 
            } 
            return true;
        } 

        internal static IEnumerable GetNonSystemReferencedAssemblies(Assembly assembly)
        {
            foreach (AssemblyName name in assembly.GetReferencedAssemblies()) 
            {
                if (!ShouldFilterAssembly(name)) 
                { 
                    Assembly referenceAssembly = SafeLoadReferencedAssembly(name);
                    if(referenceAssembly != null ) 
                    {
                        yield return referenceAssembly;
                    }
                } 
            }
        } 
     } 
}

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

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