// Copyright (c) 2012 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 "base/base_export.h" #include "base/base_paths.h" #include "base/gtest_prod_util.h" #include "build/build_config.h" namespace base { class FilePath; class ScopedPathOverride; // The path service is a global table mapping keys to file system paths. It is // OK to use this service from multiple threads. // class BASE_EXPORT PathService { public: // Populates |path| with a special directory or file. Returns true on success, // in which case |path| is guaranteed to have a non-empty value. On failure, // |path| will not be changed. static bool Get(int key, FilePath* path); // Returns the corresponding path; CHECKs that the operation succeeds. static FilePath CheckedGet(int key); // 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. // // Unit tests generally should use ScopedPathOverride instead. Overrides from // one test should not carry over to another. static bool Override(int key, const FilePath& path); // This function does the same as PathService::Override but it takes extra // parameters: // - |is_absolute| indicates that |path| has already been expanded into an // absolute path, otherwise MakeAbsoluteFilePath() will be used. This is // useful to override paths that may not exist yet, since MakeAbsoluteFilePath // fails for those. Note that MakeAbsoluteFilePath also expands symbolic // links, even if path.IsAbsolute() is already true. // - |create| guides whether the directory to be overriden must // be created in case it doesn't exist already. static bool OverrideAndCreateIfNeeded(int key, const FilePath& path, bool is_absolute, bool create); // 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 a 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); // Disable internal cache. static void DisableCache(); private: friend class ScopedPathOverride; FRIEND_TEST_ALL_PREFIXES(PathServiceTest, RemoveOverride); // Removes an override for a special directory or file. Returns true if there // was an override to remove or false if none was present. static bool RemoveOverrideForTests(int key); // Returns whether an override is present for a special directory or file. static bool IsOverriddenForTests(int key); }; } // namespace base #endif // BASE_PATH_SERVICE_H_