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//------------------------------------------------------------------------------
// <copyright file="VirtualPathProvider.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.Hosting {
using System;
using System.IO;
using System.Collections;
using System.Globalization;
using System.Configuration;
using System.Web.Caching;
using System.Web.Util;
using Util=System.Web.UI.Util;
using System.Security.Permissions;
/*
* Base class for virtual path providers
*/
public abstract class VirtualPathProvider: MarshalByRefObject {
private VirtualPathProvider _previous;
public override Object InitializeLifetimeService(){
return null; // never expire lease
}
internal virtual void Initialize(VirtualPathProvider previous) {
_previous = previous;
Initialize();
}
/*
* Initialize is called on the provider after it is registered.
*/
protected virtual void Initialize() {
}
/*
* Gives the provider access to the Previous provider. It can be used to delegate some of the calls
* (e.g. as a way of having some files comes from the file system, and others from the database)
*/
protected internal VirtualPathProvider Previous { get { return _previous; } }
/*
* Asks the provider for a hash string based on the state of a set of virtual paths.
* The primary virtualPath is also passed in by itself.
* If they match, the cached data held by the user of the provider is still
* valid. Otherwise, it should be discarded, and a new version needs to be
* obtained via GetFile/GetDirectory.
*/
public virtual string GetFileHash(string virtualPath, IEnumerable virtualPathDependencies) {
// Delegate to the previous VirtualPathProvider, if any
if (_previous == null)
return null;
return _previous.GetFileHash(virtualPath, virtualPathDependencies);
}
internal string GetFileHash(VirtualPath virtualPath, IEnumerable virtualPathDependencies) {
return GetFileHash(virtualPath.VirtualPathString, virtualPathDependencies);
}
/*
* Asks the provider for a CacheDependency that will be invalidated if any of the
* input files become invalid.
* utcStart contains the time (UTC) at which the files were read. Any change to the file
* made after that time (even if the change is in the past) should invalidate the
* CacheDependency.
* If the provider doesn't support using a CacheDependency, it should return null,
* or simply not override GetCacheDependency (the base implementation returns null).
*/
public virtual CacheDependency GetCacheDependency(string virtualPath, IEnumerable virtualPathDependencies, DateTime utcStart) {
// Delegate to the previous VirtualPathProvider, if any
if (_previous == null) {
return null;
}
return _previous.GetCacheDependency(virtualPath, virtualPathDependencies, utcStart);
}
internal CacheDependency GetCacheDependency(VirtualPath virtualPath, IEnumerable virtualPathDependencies, DateTime utcStart) {
return GetCacheDependency(virtualPath.VirtualPathString, virtualPathDependencies, utcStart);
}
/*
* Returns whether the file described by the virtual path exists from
* the point of view of this provider.
*/
public virtual bool FileExists(string virtualPath) {
// Delegate to the previous VirtualPathProvider, if any
if (_previous == null)
return false;
return _previous.FileExists(virtualPath);
}
internal bool FileExists(VirtualPath virtualPath) {
return FileExists(virtualPath.VirtualPathString);
}
/*
* Returns whether the directory described by the virtual path exists from
* the point of view of this provider.
*/
public virtual bool DirectoryExists(string virtualDir) {
// Delegate to the previous VirtualPathProvider, if any
if (_previous == null)
return false;
return _previous.DirectoryExists(virtualDir);
}
internal bool DirectoryExists(VirtualPath virtualDir) {
return DirectoryExists(virtualDir.VirtualPathString);
}
/*
* Returns a VirtualFile object for the passed in virtual path
*/
public virtual VirtualFile GetFile(string virtualPath) {
// Delegate to the previous VirtualPathProvider, if any
if (_previous == null)
return null;
return _previous.GetFile(virtualPath);
}
internal VirtualFile GetFile(VirtualPath virtualPath) {
return GetFileWithCheck(virtualPath.VirtualPathString);
}
internal VirtualFile GetFileWithCheck(string virtualPath) {
VirtualFile virtualFile = GetFile(virtualPath);
if (virtualFile == null)
return null;
// Make sure the VirtualFile's path is the same as what was passed to GetFile
if (!StringUtil.EqualsIgnoreCase(virtualPath, virtualFile.VirtualPath)) {
throw new HttpException(SR.GetString(SR.Bad_VirtualPath_in_VirtualFileBase,
"VirtualFile", virtualFile.VirtualPath, virtualPath));
}
return virtualFile;
}
/*
* Returns a VirtualDirectory object for the passed in virtual path
*/
public virtual VirtualDirectory GetDirectory(string virtualDir) {
// Delegate to the previous VirtualPathProvider, if any
if (_previous == null)
return null;
return _previous.GetDirectory(virtualDir);
}
internal VirtualDirectory GetDirectory(VirtualPath virtualDir) {
Debug.Assert(virtualDir.HasTrailingSlash);
return GetDirectoryWithCheck(virtualDir.VirtualPathString);
}
internal VirtualDirectory GetDirectoryWithCheck(string virtualPath) {
VirtualDirectory virtualDir = GetDirectory(virtualPath);
if (virtualDir == null)
return null;
// Make sure the VirtualDirectory's path is the same as what was passed to GetDirectory
if (!StringUtil.EqualsIgnoreCase(virtualPath, virtualDir.VirtualPath)) {
throw new HttpException(SR.GetString(SR.Bad_VirtualPath_in_VirtualFileBase,
"VirtualDirectory", virtualDir.VirtualPath, virtualPath));
}
return virtualDir;
}
#if OLD
/*
* Allow the file provider to replace a virtual path by a different (ghosted) one. This can
* be used to have several virtual paths be mapped to the same compilation, hence saving
* resources. If the path is not ghosted, this method must return null.
*/
public virtual string GetGhostedVirtualPath(string virtualPath) {
// By default, it's not supported
return null;
}
#endif
/*
* Returns a cache key to be used for this virtual path. If not overridden, this returns
* null meaning that the virtual path itself should be used as the cache key.
* This should only be overridden to achieve Sharepoint like ghosting behavior.
*/
public virtual string GetCacheKey(string virtualPath) {
// By default, return null, meaning use a key based on the virtual path
return null;
}
internal string GetCacheKey(VirtualPath virtualPath) {
return GetCacheKey(virtualPath.VirtualPathString);
}
/*
* Allows the VirtualPathProvider to use custom logic to combine virtual path.
* This can be used to give a special meaning to app relative paths (DevDiv 31438).
* basePath is the path to the file in which the relative reference was found.
*/
public virtual string CombineVirtualPaths(string basePath, string relativePath) {
string baseDir = null;
if (!String.IsNullOrEmpty(basePath))
baseDir = UrlPath.GetDirectory(basePath);
// By default, just combine them normally
return UrlPath.Combine(baseDir, relativePath);
}
internal VirtualPath CombineVirtualPaths(VirtualPath basePath, VirtualPath relativePath) {
string virtualPath = CombineVirtualPaths(basePath.VirtualPathString,
relativePath.VirtualPathString);
return VirtualPath.Create(virtualPath);
}
/*
* Helper method to open a file from its virtual path
*/
public static Stream OpenFile(string virtualPath) {
VirtualPathProvider vpathProvider = HostingEnvironment.VirtualPathProvider;
VirtualFile vfile = vpathProvider.GetFileWithCheck(virtualPath);
return vfile.Open();
}
internal static Stream OpenFile(VirtualPath virtualPath) {
return OpenFile(virtualPath.VirtualPathString);
}
internal static CacheDependency GetCacheDependency(VirtualPath virtualPath) {
VirtualPathProvider vpathProvider = HostingEnvironment.VirtualPathProvider;
return vpathProvider.GetCacheDependency(virtualPath,
new SingleObjectCollection(virtualPath.VirtualPathString), DateTime.MaxValue);
}
/*
* Helper method to call CombineVirtualPaths if there is a VirtualPathProvider
*/
internal static VirtualPath CombineVirtualPathsInternal(VirtualPath basePath, VirtualPath relativePath) {
VirtualPathProvider vpathProvider = HostingEnvironment.VirtualPathProvider;
if (vpathProvider != null) {
return vpathProvider.CombineVirtualPaths(basePath, relativePath);
}
// If there is no provider, just combine them normally
return basePath.Parent.Combine(relativePath);
}
internal static bool DirectoryExistsNoThrow(string virtualDir) {
try {
return HostingEnvironment.VirtualPathProvider.DirectoryExists(virtualDir);
}
catch {
// If it throws, act is if it doesn't exist
return false;
}
}
internal static bool DirectoryExistsNoThrow(VirtualPath virtualDir) {
return DirectoryExistsNoThrow(virtualDir.VirtualPathString);
}
}
/*
* Base class for VirtualFile and VirtualDirectory. This is analogous to
* System.IO.FileSystemInfo, but for virtual paths instead of physical.
*/
public abstract class VirtualFileBase: MarshalByRefObject {
internal VirtualPath _virtualPath;
public override Object InitializeLifetimeService(){
return null; // never expire lease
}
/*
* Returns the name of the file or directory, without any path info.
* e.g. if the virtual path is /app/sub/foo.aspx, this returns foo.aspx.
* Note that this is expected to return the name in the correct casing,
* which may be different from the casing in the original virtual path.
*/
public virtual string Name {
get {
// By default, return the last chunk of the virtual path
return _virtualPath.FileName;
}
}
/*
* Returns the virtual path to the file or directory that this object
* represents. This is typically the path passed in to the constructor.
*/
public string VirtualPath {
get { return _virtualPath.VirtualPathString; }
}
internal VirtualPath VirtualPathObject {
get { return _virtualPath; }
}
/*
* Returns true if this is a directory, and false if its a file
*/
public abstract bool IsDirectory {get;}
}
/*
* Object that represents a virtual file. This is analogous to
* System.IO.FileInfo, but for virtual paths instead of physical.
*/
public abstract class VirtualFile: VirtualFileBase {
/*
* Contructs a VirtualFile, passing it the virtual path to the
* file it represents
*/
protected VirtualFile(string virtualPath) {
_virtualPath = System.Web.VirtualPath.Create(virtualPath);
}
public override bool IsDirectory {
get { return false; }
}
/*
* Returns a readonly stream to the file
*/
public abstract Stream Open();
}
/*
* Object that represents a virtual directory. This is analogous to
* System.IO.DirectoryInfo, but for virtual paths instead of physical.
*/
public abstract class VirtualDirectory: VirtualFileBase {
/*
* Contructs a VirtualDirectory, passing it the virtual path to the
* directory it represents
*/
protected VirtualDirectory(string virtualPath) {
// Make sure it always has a trailing slash
_virtualPath = System.Web.VirtualPath.CreateTrailingSlash(virtualPath);
}
public override bool IsDirectory {
get { return true; }
}
/*
* Returns an object that enumerates all the children VirtualDirectory's
* of this directory.
*/
public abstract IEnumerable Directories {get;}
/*
* Returns an object that enumerates all the children VirtualFile's
* of this directory.
*/
public abstract IEnumerable Files {get;}
/*
* Returns an object that enumerates all the children VirtualDirectory's
* and VirtualFiles of this directory.
*/
public abstract IEnumerable Children {get;}
}
}
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