The Tor Browser / file revision

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.

 // Use of this source code is governed by a BSD-style license that can be

 // found in the LICENSE file.

 #ifndef BASE_PATH_SERVICE_H__

 #define BASE_PATH_SERVICE_H__

 #include "build/build_config.h"

 #ifdef OS_WIN

 // TODO(erikkay): this should be removable, but because SetCurrentDirectory

 // is the name of a Windows function, it gets macro-ized to SetCurrentDirectoryW

 // by windows.h, which leads to a different name in the header vs. the impl.

 // Even if we could fix that, it would still hose all callers of the function.

 // The right thing is likely to rename.

 #include <windows.h>

 #endif

 #include <string>

 #include "base/base_paths.h"

 class FilePath;

 // The path service is a global table mapping keys to file system paths.  It is

 // OK to use this service from multiple threads.

 //

 class PathService {

  public:

   // Retrieves a path to a special directory or file and places it into the

   // string pointed to by 'path'. If you ask for a directory it is guaranteed

   // to NOT have a path separator at the end. For example, "c:\windows\temp"

   // Directories are also guaranteed to exist when this function succeeds.

   //

   // Returns true if the directory or file was successfully retrieved. On

   // failure, 'path' will not be changed.

   static bool Get(int key, FilePath* path);

   // This version, producing a wstring, is deprecated and only kept around

   // until we can fix all callers.

   static bool Get(int key, std::wstring* path);

   // Overrides the path to a special directory or file.  This cannot be used to

   // change the value of DIR_CURRENT, but that should be obvious.  Also, if the

   // path specifies a directory that does not exist, the directory will be

   // created by this method.  This method returns true if successful.

   //

   // If the given path is relative, then it will be resolved against

   // DIR_CURRENT.

   //

   // WARNING: Consumers of PathService::Get may expect paths to be constant

   // over the lifetime of the app, so this method should be used with caution.

   static bool Override(int key, const std::wstring& path);

   // Return whether a path was overridden.

   static bool IsOverridden(int key);

   // Sets the current directory.

   static bool SetCurrentDirectory(const std::wstring& current_directory);

   // To extend the set of supported keys, you can register a path provider,

   // which is just a function mirroring PathService::Get.  The ProviderFunc

   // returns false if it cannot provide a non-empty path for the given key.

   // Otherwise, true is returned.

   //

   // WARNING: This function could be called on any thread from which the

   // PathService is used, so the ProviderFunc MUST BE THREADSAFE.

   //

   typedef bool (*ProviderFunc)(int, FilePath*);

   // Call to register a path provider.  You must specify the range "[key_start,

   // key_end)" of supported path keys.

   static void RegisterProvider(ProviderFunc provider,

                                int key_start,

                                int key_end);

  private:

   static bool GetFromCache(int key, FilePath* path);

   static void AddToCache(int key, const FilePath& path);

 };

 #endif // BASE_PATH_SERVICE_H__