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Diffstat (limited to 'ipc/chromium/src/base/file_path.h')
| -rw-r--r-- | ipc/chromium/src/base/file_path.h | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/ipc/chromium/src/base/file_path.h b/ipc/chromium/src/base/file_path.h new file mode 100644 index 000000000..b2e9f9a00 --- /dev/null +++ b/ipc/chromium/src/base/file_path.h @@ -0,0 +1,277 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +// Copyright (c) 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. + +// FilePath is a container for pathnames stored in a platform's native string +// type, providing containers for manipulation in according with the +// platform's conventions for pathnames. It supports the following path +// types: +// +// POSIX Windows +// --------------- ---------------------------------- +// Fundamental type char[] wchar_t[] +// Encoding unspecified* UTF-16 +// Separator / \, tolerant of / +// Drive letters no case-insensitive A-Z followed by : +// Alternate root // (surprise!) \\, for UNC paths +// +// * The encoding need not be specified on POSIX systems, although some +// POSIX-compliant systems do specify an encoding. Mac OS X uses UTF-8. +// Linux does not specify an encoding, but in practice, the locale's +// character set may be used. +// +// FilePath objects are intended to be used anywhere paths are. An +// application may pass FilePath objects around internally, masking the +// underlying differences between systems, only differing in implementation +// where interfacing directly with the system. For example, a single +// OpenFile(const FilePath &) function may be made available, allowing all +// callers to operate without regard to the underlying implementation. On +// POSIX-like platforms, OpenFile might wrap fopen, and on Windows, it might +// wrap _wfopen_s, perhaps both by calling file_path.value().c_str(). This +// allows each platform to pass pathnames around without requiring conversions +// between encodings, which has an impact on performance, but more imporantly, +// has an impact on correctness on platforms that do not have well-defined +// encodings for pathnames. +// +// Several methods are available to perform common operations on a FilePath +// object, such as determining the parent directory (DirName), isolating the +// final path component (BaseName), and appending a relative pathname string +// to an existing FilePath object (Append). These methods are highly +// recommended over attempting to split and concatenate strings directly. +// These methods are based purely on string manipulation and knowledge of +// platform-specific pathname conventions, and do not consult the filesystem +// at all, making them safe to use without fear of blocking on I/O operations. +// These methods do not function as mutators but instead return distinct +// instances of FilePath objects, and are therefore safe to use on const +// objects. The objects themselves are safe to share between threads. +// +// To aid in initialization of FilePath objects from string literals, a +// FILE_PATH_LITERAL macro is provided, which accounts for the difference +// between char[]-based pathnames on POSIX systems and wchar_t[]-based +// pathnames on Windows. +// +// Because a FilePath object should not be instantiated at the global scope, +// instead, use a FilePath::CharType[] and initialize it with +// FILE_PATH_LITERAL. At runtime, a FilePath object can be created from the +// character array. Example: +// +// | const FilePath::CharType kLogFileName[] = FILE_PATH_LITERAL("log.txt"); +// | +// | void Function() { +// | FilePath log_file_path(kLogFileName); +// | [...] +// | } + +#ifndef BASE_FILE_PATH_H_ +#define BASE_FILE_PATH_H_ + +#include <string> + +#include "base/basictypes.h" +#include "base/compiler_specific.h" +#include "base/hash_tables.h" + +// Windows-style drive letter support and pathname separator characters can be +// enabled and disabled independently, to aid testing. These #defines are +// here so that the same setting can be used in both the implementation and +// in the unit test. +#if defined(OS_WIN) +#define FILE_PATH_USES_DRIVE_LETTERS +#define FILE_PATH_USES_WIN_SEPARATORS +#endif // OS_WIN + +// An abstraction to isolate users from the differences between native +// pathnames on different platforms. +class FilePath { + public: +#if defined(OS_POSIX) + // On most platforms, native pathnames are char arrays, and the encoding + // may or may not be specified. On Mac OS X, native pathnames are encoded + // in UTF-8. + typedef std::string StringType; +#elif defined(OS_WIN) + // On Windows, for Unicode-aware applications, native pathnames are wchar_t + // arrays encoded in UTF-16. + typedef std::wstring StringType; +#endif // OS_WIN + + typedef StringType::value_type CharType; + + // Null-terminated array of separators used to separate components in + // hierarchical paths. Each character in this array is a valid separator, + // but kSeparators[0] is treated as the canonical separator and will be used + // when composing pathnames. + static const CharType kSeparators[]; + + // A special path component meaning "this directory." + static const CharType kCurrentDirectory[]; + + // A special path component meaning "the parent directory." + static const CharType kParentDirectory[]; + + // The character used to identify a file extension. + static const CharType kExtensionSeparator; + + FilePath() {} + FilePath(const FilePath& that) : path_(that.path_) {} + explicit FilePath(const StringType& path) : path_(path) {} + +#if defined(OS_WIN) + explicit FilePath(const wchar_t* path) : path_(path) {} +#endif + + FilePath& operator=(const FilePath& that) { + path_ = that.path_; + return *this; + } + + bool operator==(const FilePath& that) const { + return path_ == that.path_; + } + + bool operator!=(const FilePath& that) const { + return path_ != that.path_; + } + + // Required for some STL containers and operations + bool operator<(const FilePath& that) const { + return path_ < that.path_; + } + + const StringType& value() const { return path_; } + + bool empty() const { return path_.empty(); } + + // Returns true if |character| is in kSeparators. + static bool IsSeparator(CharType character); + + // Returns a FilePath corresponding to the directory containing the path + // named by this object, stripping away the file component. If this object + // only contains one component, returns a FilePath identifying + // kCurrentDirectory. If this object already refers to the root directory, + // returns a FilePath identifying the root directory. + FilePath DirName() const; + + // Returns a FilePath corresponding to the last path component of this + // object, either a file or a directory. If this object already refers to + // the root directory, returns a FilePath identifying the root directory; + // this is the only situation in which BaseName will return an absolute path. + FilePath BaseName() const; + + // Returns ".jpg" for path "C:\pics\jojo.jpg", or an empty string if + // the file has no extension. If non-empty, Extension() will always start + // with precisely one ".". The following code should always work regardless + // of the value of path. + // new_path = path.RemoveExtension().value().append(path.Extension()); + // ASSERT(new_path == path.value()); + // NOTE: this is different from the original file_util implementation which + // returned the extension without a leading "." ("jpg" instead of ".jpg") + StringType Extension() const; + + // Returns "C:\pics\jojo" for path "C:\pics\jojo.jpg" + // NOTE: this is slightly different from the similar file_util implementation + // which returned simply 'jojo'. + FilePath RemoveExtension() const; + + // Inserts |suffix| after the file name portion of |path| but before the + // extension. Returns "" if BaseName() == "." or "..". + // Examples: + // path == "C:\pics\jojo.jpg" suffix == " (1)", returns "C:\pics\jojo (1).jpg" + // path == "jojo.jpg" suffix == " (1)", returns "jojo (1).jpg" + // path == "C:\pics\jojo" suffix == " (1)", returns "C:\pics\jojo (1)" + // path == "C:\pics.old\jojo" suffix == " (1)", returns "C:\pics.old\jojo (1)" + FilePath InsertBeforeExtension(const StringType& suffix) const; + + // Replaces the extension of |file_name| with |extension|. If |file_name| + // does not have an extension, them |extension| is added. If |extension| is + // empty, then the extension is removed from |file_name|. + // Returns "" if BaseName() == "." or "..". + FilePath ReplaceExtension(const StringType& extension) const; + + // Returns a FilePath by appending a separator and the supplied path + // component to this object's path. Append takes care to avoid adding + // excessive separators if this object's path already ends with a separator. + // If this object's path is kCurrentDirectory, a new FilePath corresponding + // only to |component| is returned. |component| must be a relative path; + // it is an error to pass an absolute path. + FilePath Append(const StringType& component) const WARN_UNUSED_RESULT; + FilePath Append(const FilePath& component) const WARN_UNUSED_RESULT; + + // Although Windows StringType is std::wstring, since the encoding it uses for + // paths is well defined, it can handle ASCII path components as well. + // Mac uses UTF8, and since ASCII is a subset of that, it works there as well. + // On Linux, although it can use any 8-bit encoding for paths, we assume that + // ASCII is a valid subset, regardless of the encoding, since many operating + // system paths will always be ASCII. + FilePath AppendASCII(const std::string& component) const WARN_UNUSED_RESULT; + + // Returns true if this FilePath contains an absolute path. On Windows, an + // absolute path begins with either a drive letter specification followed by + // a separator character, or with two separator characters. On POSIX + // platforms, an absolute path begins with a separator character. + bool IsAbsolute() const; + + // Returns a copy of this FilePath that does not end with a trailing + // separator. + FilePath StripTrailingSeparators() const; + + // Calls open on given ifstream instance + void OpenInputStream(std::ifstream &stream) const; + + // Older Chromium code assumes that paths are always wstrings. + // This function converts a wstring to a FilePath, and is useful to smooth + // porting that old code to the FilePath API. + // It has "Hack" in its name so people feel bad about using it. + // TODO(port): remove these functions. + static FilePath FromWStringHack(const std::wstring& wstring); + + // Older Chromium code assumes that paths are always wstrings. + // This function produces a wstring from a FilePath, and is useful to smooth + // porting that old code to the FilePath API. + // It has "Hack" in its name so people feel bad about using it. + // TODO(port): remove these functions. + std::wstring ToWStringHack() const; + + private: + // Remove trailing separators from this object. If the path is absolute, it + // will never be stripped any more than to refer to the absolute root + // directory, so "////" will become "/", not "". A leading pair of + // separators is never stripped, to support alternate roots. This is used to + // support UNC paths on Windows. + void StripTrailingSeparatorsInternal(); + + StringType path_; +}; + +// Macros for string literal initialization of FilePath::CharType[]. +#if defined(OS_POSIX) +#define FILE_PATH_LITERAL(x) x +#elif defined(OS_WIN) +#define FILE_PATH_LITERAL(x) L ## x +#endif // OS_WIN + +// Implement hash function so that we can use FilePaths in hashsets and maps. +#if defined(COMPILER_GCC) && !defined(ANDROID) +namespace __gnu_cxx { + +template<> +struct hash<FilePath> { + size_t operator()(const FilePath& f) const { + return hash<FilePath::StringType>()(f.value()); + } +}; + +} // namespace __gnu_cxx +#elif defined(COMPILER_MSVC) +namespace stdext { + +inline size_t hash_value(const FilePath& f) { + return hash_value(f.value()); +} + +} // namespace stdext +#endif // COMPILER + +#endif // BASE_FILE_PATH_H_ |