MetadataArtifactLoaderResource.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 / MetadataArtifactLoaderResource.cs / 1305376 / MetadataArtifactLoaderResource.cs

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

using System.Collections.Generic; 
using System.Collections;
using System.Diagnostics;
using System.Globalization;
using System.Reflection; 
using System.Text;
using System.Xml; 
using System.Data.Mapping; 
using System.IO;
using System.Security; 
using System.Security.Permissions;
using System.Security.Cryptography;
using System.Data.EntityModel.SchemaObjectModel;
 

namespace System.Data.Metadata.Edm 
{ 
    /// 
    /// This class represents one resource item to be loaded from an assembly. 
    /// 
    internal class MetadataArtifactLoaderResource : MetadataArtifactLoader, IComparable
    {
        private readonly bool _alreadyLoaded = false; 
        private readonly Assembly _assembly;
        private readonly string _resourceName; 
 
        /// 
        /// Constructor - loads the resource stream 
        /// 
        /// The path to the resource to load
        /// The global registry of URIs
        internal MetadataArtifactLoaderResource(Assembly assembly, string resourceName, ICollection uriRegistry) 
        {
            Debug.Assert(assembly != null); 
            Debug.Assert(resourceName != null); 

            _assembly = assembly; 
            _resourceName = resourceName;

            string tempPath = MetadataArtifactLoaderCompositeResource.CreateResPath(_assembly, _resourceName);
            _alreadyLoaded = uriRegistry.Contains(tempPath); 
            if (!_alreadyLoaded)
            { 
                uriRegistry.Add(tempPath); 

                // '_alreadyLoaded' is not set because while we would like to prevent 
                // other instances of MetadataArtifactLoaderFile that wrap the same
                // _path from being added to the list of paths/readers, we do want to
                // include this particular instance.
            } 
        }
 
        public override string Path 
        {
            get 
            {
                return MetadataArtifactLoaderCompositeResource.CreateResPath(_assembly, _resourceName);
            }
        } 

        ///  
        /// Implementation of IComparable.CompareTo() 
        /// 
        /// The object to compare to 
        /// 0 if the loaders are "equal" (i.e., have the same _path value)
        public int CompareTo(object obj)
        {
            MetadataArtifactLoaderResource loader = obj as MetadataArtifactLoaderResource; 
            if (loader != null)
            { 
                return string.Compare(Path, loader.Path, StringComparison.OrdinalIgnoreCase); 
            }
 
            Debug.Assert(false, "object is not a MetadataArtifactLoaderResource");
            return -1;
        }
 
        /// 
        /// Equals() returns true if the objects have the same _path value 
        ///  
        /// The object to compare to
        /// true if the objects have the same _path value 
        public override bool Equals(object obj)
        {
            return this.CompareTo(obj) == 0;
        } 

        ///  
        /// GetHashCode override that defers the result to the _path member variable. 
        /// 
        ///  
        public override int GetHashCode()
        {
            return Path.GetHashCode();
        } 

        public override void CollectFilePermissionPaths(List paths, DataSpace spaceToGet) 
        { 
            // does not apply
        } 

        /// 
        /// Get paths to artifacts for a specific DataSpace.
        ///  
        /// The DataSpace for the artifacts of interest
        /// A List of strings identifying paths to all artifacts for a specific DataSpace 
        public override List GetPaths(DataSpace spaceToGet) 
        {
            List list = new List(); 
            if (!_alreadyLoaded && MetadataArtifactLoader.IsArtifactOfDataSpace(Path, spaceToGet))
            {
                list.Add(Path);
            } 
            return list;
        } 
 
        /// 
        /// Get paths to all artifacts 
        /// 
        /// A List of strings identifying paths to all resources
        public override List GetPaths()
        { 
            List list = new List();
            if (!_alreadyLoaded) 
            { 
                list.Add(Path);
            } 
            return list;
        }

        ///  
        /// Create and return an XmlReader around the resource represented by this instance.
        ///  
        /// A List of XmlReaders for all resources 
        public override List GetReaders(Dictionary sourceDictionary)
        { 
            List list = new List();
            if (!_alreadyLoaded)
            {
 
                XmlReader reader = CreateReader();
                list.Add(reader); 
 
                if (sourceDictionary != null)
                { 
                    sourceDictionary.Add(this, reader);
                }
            }
            return list; 
        }
 
        private XmlReader CreateReader() 
        {
 
            Stream stream = LoadResource();

            XmlReaderSettings readerSettings = Schema.CreateEdmStandardXmlReaderSettings();
            // close the stream when the xmlreader is closed 
            // now the reader owns the stream
            readerSettings.CloseInput = true; 
 
            // we know that we aren't reading a fragment
            readerSettings.ConformanceLevel = ConformanceLevel.Document; 
            XmlReader reader = XmlReader.Create(stream, readerSettings);
            // cannot set the base URI because res:// URIs cause the schema parser
            // to choke
 
            return reader;
        } 
 
        /// 
        /// Create and return an XmlReader around the resource represented by this instance 
        /// if it is of the requested DataSpace type.
        /// 
        /// The DataSpace corresponding to the requested artifacts
        /// A List of XmlReader objects 
        public override List CreateReaders(DataSpace spaceToGet)
        { 
            List list = new List(); 
            if (!_alreadyLoaded)
            { 
                if (MetadataArtifactLoader.IsArtifactOfDataSpace(Path, spaceToGet))
                {
                    XmlReader reader = CreateReader();
                    list.Add(reader); 
                }
            } 
            return list; 
        }
 
        /// 
        /// This method parses the path to the resource and attempts to load it.
        /// The method also accounts for the wildcard assembly name.
        ///  
        private Stream LoadResource()
        { 
            Stream resourceStream; 
            if (TryCreateResourceStream(out resourceStream))
            { 
                return resourceStream;
            }
            throw EntityUtil.Metadata(System.Data.Entity.Strings.UnableToLoadResource);
        } 

        private bool TryCreateResourceStream(out Stream resourceStream) 
        { 
            resourceStream = _assembly.GetManifestResourceStream(_resourceName);
            return resourceStream != null; 
        }
    }
}

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


                        

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