MetadataArtifactLoaderFile.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 / MetadataArtifactLoaderFile.cs / 1305376 / MetadataArtifactLoaderFile.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;
using System.Threading; 
using System.Runtime.Versioning;
 
namespace System.Data.Metadata.Edm 
{
    ///  
    /// This class represents one file-based artifact item to be loaded.
    /// 
    internal class MetadataArtifactLoaderFile : MetadataArtifactLoader, IComparable
    { 
        /// 
        /// This member indicates whether the file-based artifact has already been loaded. 
        /// It is used to prevent other instances of this class from (re)loading the same 
        /// artifact. See comment in the MetadataArtifactLoaderFile c'tor below.
        ///  
        private readonly bool _alreadyLoaded = false;
        private readonly string _path;

        ///  
        /// Constructor
        ///  
        /// The path to the resource to load 
        /// The global registry of URIs
        [ResourceExposure(ResourceScope.Machine)] //Exposes the file path which is a Machine resource 
        public MetadataArtifactLoaderFile(string path, ICollection uriRegistry)
        {
            _path = path;
            _alreadyLoaded = uriRegistry.Contains(_path); 
            if (!_alreadyLoaded)
            { 
                uriRegistry.Add(_path); 

                // '_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 _path; } 
        }

        /// 
        /// 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)
        { 
            MetadataArtifactLoaderFile loader = obj as MetadataArtifactLoaderFile;
            if (loader != null)
            {
                return string.Compare(_path, loader._path, StringComparison.OrdinalIgnoreCase); 
            }
 
            Debug.Assert(false, "object is not a MetadataArtifactLoaderFile"); 
            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)
        { 
            if (!_alreadyLoaded && MetadataArtifactLoader.IsArtifactOfDataSpace(_path, spaceToGet))
            { 
                paths.Add(_path); 
            }
        } 
        /// 
        /// 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 file 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 = CreateXmlReader();
                list.Add(reader); 
                if (sourceDictionary != null)
                { 
                    sourceDictionary.Add(this, reader); 
                }
            } 
            return list;
        }

        ///  
        /// Create and return an XmlReader around the file 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 && MetadataArtifactLoader.IsArtifactOfDataSpace(_path, spaceToGet)) 
            {
                XmlReader reader = CreateXmlReader(); 
                list.Add(reader); 
            }
            return list; 
        }

        /// 
        /// Create an XmlReader around the artifact file 
        /// 
        /// An XmlReader that wraps a file 
        [ResourceExposure(ResourceScope.None)] //The file path is not passed through to this method so nothing to expose in this method. 
        [ResourceConsumption(ResourceScope.Machine, ResourceScope.Machine)] //We are not changing the scope of consumption here
        private XmlReader CreateXmlReader() 
        {
            XmlReaderSettings readerSettings = Schema.CreateEdmStandardXmlReaderSettings();
            // we know that we aren't reading a fragment
            readerSettings.ConformanceLevel = ConformanceLevel.Document; 
            return XmlReader.Create(_path, readerSettings);
        } 
 
    }
} 

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

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