michael@0: // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_PATH_SERVICE_H__
michael@0: #define BASE_PATH_SERVICE_H__
michael@0: 
michael@0: #include "build/build_config.h"
michael@0: #ifdef OS_WIN
michael@0: // TODO(erikkay): this should be removable, but because SetCurrentDirectory
michael@0: // is the name of a Windows function, it gets macro-ized to SetCurrentDirectoryW
michael@0: // by windows.h, which leads to a different name in the header vs. the impl.
michael@0: // Even if we could fix that, it would still hose all callers of the function.
michael@0: // The right thing is likely to rename.
michael@0: #include <windows.h>
michael@0: #endif
michael@0: 
michael@0: #include <string>
michael@0: 
michael@0: #include "base/base_paths.h"
michael@0: 
michael@0: class FilePath;
michael@0: 
michael@0: // The path service is a global table mapping keys to file system paths.  It is
michael@0: // OK to use this service from multiple threads.
michael@0: //
michael@0: class PathService {
michael@0:  public:
michael@0:   // Retrieves a path to a special directory or file and places it into the
michael@0:   // string pointed to by 'path'. If you ask for a directory it is guaranteed
michael@0:   // to NOT have a path separator at the end. For example, "c:\windows\temp"
michael@0:   // Directories are also guaranteed to exist when this function succeeds.
michael@0:   //
michael@0:   // Returns true if the directory or file was successfully retrieved. On
michael@0:   // failure, 'path' will not be changed.
michael@0:   static bool Get(int key, FilePath* path);
michael@0:   // This version, producing a wstring, is deprecated and only kept around
michael@0:   // until we can fix all callers.
michael@0:   static bool Get(int key, std::wstring* path);
michael@0: 
michael@0:   // Overrides the path to a special directory or file.  This cannot be used to
michael@0:   // change the value of DIR_CURRENT, but that should be obvious.  Also, if the
michael@0:   // path specifies a directory that does not exist, the directory will be
michael@0:   // created by this method.  This method returns true if successful.
michael@0:   //
michael@0:   // If the given path is relative, then it will be resolved against
michael@0:   // DIR_CURRENT.
michael@0:   //
michael@0:   // WARNING: Consumers of PathService::Get may expect paths to be constant
michael@0:   // over the lifetime of the app, so this method should be used with caution.
michael@0:   static bool Override(int key, const std::wstring& path);
michael@0: 
michael@0:   // Return whether a path was overridden.
michael@0:   static bool IsOverridden(int key);
michael@0: 
michael@0:   // Sets the current directory.
michael@0:   static bool SetCurrentDirectory(const std::wstring& current_directory);
michael@0: 
michael@0:   // To extend the set of supported keys, you can register a path provider,
michael@0:   // which is just a function mirroring PathService::Get.  The ProviderFunc
michael@0:   // returns false if it cannot provide a non-empty path for the given key.
michael@0:   // Otherwise, true is returned.
michael@0:   //
michael@0:   // WARNING: This function could be called on any thread from which the
michael@0:   // PathService is used, so the ProviderFunc MUST BE THREADSAFE.
michael@0:   //
michael@0:   typedef bool (*ProviderFunc)(int, FilePath*);
michael@0: 
michael@0:   // Call to register a path provider.  You must specify the range "[key_start,
michael@0:   // key_end)" of supported path keys.
michael@0:   static void RegisterProvider(ProviderFunc provider,
michael@0:                                int key_start,
michael@0:                                int key_end);
michael@0:  private:
michael@0:   static bool GetFromCache(int key, FilePath* path);
michael@0:   static void AddToCache(int key, const FilePath& path);
michael@0: 
michael@0: };
michael@0: 
michael@0: #endif // BASE_PATH_SERVICE_H__