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Diffstat (limited to 'gn/base/files/file.h')
| -rw-r--r-- | gn/base/files/file.h | 356 |
1 files changed, 0 insertions, 356 deletions
diff --git a/gn/base/files/file.h b/gn/base/files/file.h deleted file mode 100644 index 61239adb8e7..00000000000 --- a/gn/base/files/file.h +++ /dev/null @@ -1,356 +0,0 @@ -// 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_FILES_FILE_H_ -#define BASE_FILES_FILE_H_ - -#include <stdint.h> - -#include <string> - -#include "base/files/file_path.h" -#include "base/files/platform_file.h" -#include "base/files/scoped_file.h" -#include "base/macros.h" -#include "util/build_config.h" -#include "util/ticks.h" - -#if defined(OS_POSIX) || defined(OS_FUCHSIA) -#include <sys/stat.h> -#endif - -namespace base { - -#if defined(OS_BSD) || defined(OS_MACOSX) || defined(OS_NACL) || \ - defined(OS_ANDROID) && __ANDROID_API__ < 21 -typedef struct stat stat_wrapper_t; -#elif defined(OS_POSIX) || defined(OS_FUCHSIA) -typedef struct stat64 stat_wrapper_t; -#endif - -// Thin wrapper around an OS-level file. -// Note that this class does not provide any support for asynchronous IO, other -// than the ability to create asynchronous handles on Windows. -// -// Note about const: this class does not attempt to determine if the underlying -// file system object is affected by a particular method in order to consider -// that method const or not. Only methods that deal with member variables in an -// obvious non-modifying way are marked as const. Any method that forward calls -// to the OS is not considered const, even if there is no apparent change to -// member variables. -class File { - public: - // FLAG_(OPEN|CREATE).* are mutually exclusive. You should specify exactly one - // of the five (possibly combining with other flags) when opening or creating - // a file. - // FLAG_(WRITE|APPEND) are mutually exclusive. This is so that APPEND behavior - // will be consistent with O_APPEND on POSIX. - // FLAG_EXCLUSIVE_(READ|WRITE) only grant exclusive access to the file on - // creation on POSIX; for existing files, consider using Lock(). - enum Flags { - FLAG_OPEN = 1 << 0, // Opens a file, only if it exists. - FLAG_CREATE = 1 << 1, // Creates a new file, only if it does not - // already exist. - FLAG_OPEN_ALWAYS = 1 << 2, // May create a new file. - FLAG_CREATE_ALWAYS = 1 << 3, // May overwrite an old file. - FLAG_OPEN_TRUNCATED = 1 << 4, // Opens a file and truncates it, only if it - // exists. - FLAG_READ = 1 << 5, - FLAG_WRITE = 1 << 6, - FLAG_APPEND = 1 << 7, - FLAG_EXCLUSIVE_READ = 1 << 8, // EXCLUSIVE is opposite of Windows SHARE. - FLAG_EXCLUSIVE_WRITE = 1 << 9, - FLAG_ASYNC = 1 << 10, - FLAG_TEMPORARY = 1 << 11, // Used on Windows only. - FLAG_HIDDEN = 1 << 12, // Used on Windows only. - FLAG_DELETE_ON_CLOSE = 1 << 13, - FLAG_WRITE_ATTRIBUTES = 1 << 14, // Used on Windows only. - FLAG_SHARE_DELETE = 1 << 15, // Used on Windows only. - FLAG_TERMINAL_DEVICE = 1 << 16, // Serial port flags. - FLAG_BACKUP_SEMANTICS = 1 << 17, // Used on Windows only. - FLAG_EXECUTE = 1 << 18, // Used on Windows only. - FLAG_SEQUENTIAL_SCAN = 1 << 19, // Used on Windows only. - FLAG_CAN_DELETE_ON_CLOSE = 1 << 20, // Requests permission to delete a file - // via DeleteOnClose() (Windows only). - // See DeleteOnClose() for details. - }; - - // This enum has been recorded in multiple histograms using PlatformFileError - // enum. If the order of the fields needs to change, please ensure that those - // histograms are obsolete or have been moved to a different enum. - // - // FILE_ERROR_ACCESS_DENIED is returned when a call fails because of a - // filesystem restriction. FILE_ERROR_SECURITY is returned when a browser - // policy doesn't allow the operation to be executed. - enum Error { - FILE_OK = 0, - FILE_ERROR_FAILED = -1, - FILE_ERROR_IN_USE = -2, - FILE_ERROR_EXISTS = -3, - FILE_ERROR_NOT_FOUND = -4, - FILE_ERROR_ACCESS_DENIED = -5, - FILE_ERROR_TOO_MANY_OPENED = -6, - FILE_ERROR_NO_MEMORY = -7, - FILE_ERROR_NO_SPACE = -8, - FILE_ERROR_NOT_A_DIRECTORY = -9, - FILE_ERROR_INVALID_OPERATION = -10, - FILE_ERROR_SECURITY = -11, - FILE_ERROR_ABORT = -12, - FILE_ERROR_NOT_A_FILE = -13, - FILE_ERROR_NOT_EMPTY = -14, - FILE_ERROR_INVALID_URL = -15, - FILE_ERROR_IO = -16, - // Put new entries here and increment FILE_ERROR_MAX. - FILE_ERROR_MAX = -17 - }; - - // This explicit mapping matches both FILE_ on Windows and SEEK_ on Linux. - enum Whence { FROM_BEGIN = 0, FROM_CURRENT = 1, FROM_END = 2 }; - - // Used to hold information about a given file. - // If you add more fields to this structure (platform-specific fields are OK), - // make sure to update all functions that use it in file_util_{win|posix}.cc, - // too, and the ParamTraits<base::File::Info> implementation in - // ipc/ipc_message_utils.cc. - struct Info { - Info(); - ~Info(); -#if defined(OS_POSIX) || defined(OS_FUCHSIA) - // Fills this struct with values from |stat_info|. - void FromStat(const stat_wrapper_t& stat_info); -#endif - - // The size of the file in bytes. Undefined when is_directory is true. - int64_t size; - - // True if the file corresponds to a directory. - bool is_directory; - - // True if the file corresponds to a symbolic link. For Windows currently - // not supported and thus always false. - bool is_symbolic_link; - - // The last modified time of a file. - Ticks last_modified; - - // The last accessed time of a file. - Ticks last_accessed; - - // The creation time of a file. - Ticks creation_time; - }; - - File(); - - // Creates or opens the given file. This will fail with 'access denied' if the - // |path| contains path traversal ('..') components. - File(const FilePath& path, uint32_t flags); - - // Takes ownership of |platform_file|. - explicit File(PlatformFile platform_file); - - // Creates an object with a specific error_details code. - explicit File(Error error_details); - - File(File&& other); - - ~File(); - - // Takes ownership of |platform_file|. - static File CreateForAsyncHandle(PlatformFile platform_file); - - File& operator=(File&& other); - - // Creates or opens the given file. - void Initialize(const FilePath& path, uint32_t flags); - - // Returns |true| if the handle / fd wrapped by this object is valid. This - // method doesn't interact with the file system (and is safe to be called from - // ThreadRestrictions::SetIOAllowed(false) threads). - bool IsValid() const; - - // Returns true if a new file was created (or an old one truncated to zero - // length to simulate a new file, which can happen with - // FLAG_CREATE_ALWAYS), and false otherwise. - bool created() const { return created_; } - - // Returns the OS result of opening this file. Note that the way to verify - // the success of the operation is to use IsValid(), not this method: - // File file(path, flags); - // if (!file.IsValid()) - // return; - Error error_details() const { return error_details_; } - - PlatformFile GetPlatformFile() const; - PlatformFile TakePlatformFile(); - - // Destroying this object closes the file automatically. - void Close(); - - // Changes current position in the file to an |offset| relative to an origin - // defined by |whence|. Returns the resultant current position in the file - // (relative to the start) or -1 in case of error. - int64_t Seek(Whence whence, int64_t offset); - - // Reads the given number of bytes (or until EOF is reached) starting with the - // given offset. Returns the number of bytes read, or -1 on error. Note that - // this function makes a best effort to read all data on all platforms, so it - // is not intended for stream oriented files but instead for cases when the - // normal expectation is that actually |size| bytes are read unless there is - // an error. - int Read(int64_t offset, char* data, int size); - - // Same as above but without seek. - int ReadAtCurrentPos(char* data, int size); - - // Reads the given number of bytes (or until EOF is reached) starting with the - // given offset, but does not make any effort to read all data on all - // platforms. Returns the number of bytes read, or -1 on error. - int ReadNoBestEffort(int64_t offset, char* data, int size); - - // Same as above but without seek. - int ReadAtCurrentPosNoBestEffort(char* data, int size); - - // Writes the given buffer into the file at the given offset, overwritting any - // data that was previously there. Returns the number of bytes written, or -1 - // on error. Note that this function makes a best effort to write all data on - // all platforms. |data| can be nullptr when |size| is 0. - // Ignores the offset and writes to the end of the file if the file was opened - // with FLAG_APPEND. - int Write(int64_t offset, const char* data, int size); - - // Save as above but without seek. - int WriteAtCurrentPos(const char* data, int size); - - // Save as above but does not make any effort to write all data on all - // platforms. Returns the number of bytes written, or -1 on error. - int WriteAtCurrentPosNoBestEffort(const char* data, int size); - - // Returns the current size of this file, or a negative number on failure. - int64_t GetLength(); - - // Truncates the file to the given length. If |length| is greater than the - // current size of the file, the file is extended with zeros. If the file - // doesn't exist, |false| is returned. - bool SetLength(int64_t length); - - // Instructs the filesystem to flush the file to disk. (POSIX: fsync, Windows: - // FlushFileBuffers). - // Calling Flush() does not guarantee file integrity and thus is not a valid - // substitute for file integrity checks and recovery codepaths for malformed - // files. It can also be *really* slow, so avoid blocking on Flush(), - // especially please don't block shutdown on Flush(). - // Latency percentiles of Flush() across all platforms as of July 2016: - // 50 % > 5 ms - // 10 % > 58 ms - // 1 % > 357 ms - // 0.1 % > 1.8 seconds - // 0.01 % > 7.6 seconds - bool Flush(); - - // Returns some basic information for the given file. - bool GetInfo(Info* info); - -#if !defined(OS_FUCHSIA) // Fuchsia's POSIX API does not support file locking. - - // Attempts to take an exclusive write lock on the file. Returns immediately - // (i.e. does not wait for another process to unlock the file). If the lock - // was obtained, the result will be FILE_OK. A lock only guarantees - // that other processes may not also take a lock on the same file with the - // same API - it may still be opened, renamed, unlinked, etc. - // - // Common semantics: - // * Locks are held by processes, but not inherited by child processes. - // * Locks are released by the OS on file close or process termination. - // * Locks are reliable only on local filesystems. - // * Duplicated file handles may also write to locked files. - // Windows-specific semantics: - // * Locks are mandatory for read/write APIs, advisory for mapping APIs. - // * Within a process, locking the same file (by the same or new handle) - // will fail. - // POSIX-specific semantics: - // * Locks are advisory only. - // * Within a process, locking the same file (by the same or new handle) - // will succeed. - // * Closing any descriptor on a given file releases the lock. - Error Lock(); - - // Unlock a file previously locked. - Error Unlock(); - -#endif // !defined(OS_FUCHSIA) - - // Returns a new object referencing this file for use within the current - // process. Handling of FLAG_DELETE_ON_CLOSE varies by OS. On POSIX, the File - // object that was created or initialized with this flag will have unlinked - // the underlying file when it was created or opened. On Windows, the - // underlying file is deleted when the last handle to it is closed. - File Duplicate() const; - - bool async() const { return async_; } - -#if defined(OS_WIN) - // Sets or clears the DeleteFile disposition on the handle. Returns true if - // the disposition was set or cleared, as indicated by |delete_on_close|. - // - // Microsoft Windows deletes a file only when the last handle to the - // underlying kernel object is closed when the DeleteFile disposition has been - // set by any handle holder. This disposition is be set by: - // - Calling the Win32 DeleteFile function with the path to a file. - // - Opening/creating a file with FLAG_DELETE_ON_CLOSE. - // - Opening/creating a file with FLAG_CAN_DELETE_ON_CLOSE and subsequently - // calling DeleteOnClose(true). - // - // In all cases, all pre-existing handles to the file must have been opened - // with FLAG_SHARE_DELETE. - // - // So: - // - Use FLAG_SHARE_DELETE when creating/opening a file to allow another - // entity on the system to cause it to be deleted when it is closed. (Note: - // another entity can delete the file the moment after it is closed, so not - // using this permission doesn't provide any protections.) - // - Use FLAG_DELETE_ON_CLOSE for any file that is to be deleted after use. - // The OS will ensure it is deleted even in the face of process termination. - // - Use FLAG_CAN_DELETE_ON_CLOSE in conjunction with DeleteOnClose() to alter - // the DeleteFile disposition on an open handle. This fine-grained control - // allows for marking a file for deletion during processing so that it is - // deleted in the event of untimely process termination, and then clearing - // this state once the file is suitable for persistence. - bool DeleteOnClose(bool delete_on_close); -#endif - -#if defined(OS_WIN) - static Error OSErrorToFileError(DWORD last_error); -#elif defined(OS_POSIX) || defined(OS_FUCHSIA) - static Error OSErrorToFileError(int saved_errno); -#endif - - // Gets the last global error (errno or GetLastError()) and converts it to the - // closest base::File::Error equivalent via OSErrorToFileError(). The returned - // value is only trustworthy immediately after another base::File method - // fails. base::File never resets the global error to zero. - static Error GetLastFileError(); - - // Converts an error value to a human-readable form. Used for logging. - static std::string ErrorToString(Error error); - - private: - // Creates or opens the given file. Only called if |path| has no - // traversal ('..') components. - void DoInitialize(const FilePath& path, uint32_t flags); - - void SetPlatformFile(PlatformFile file); - - ScopedPlatformFile file_; - - Error error_details_; - bool created_; - bool async_; - - DISALLOW_COPY_AND_ASSIGN(File); -}; - -} // namespace base - -#endif // BASE_FILES_FILE_H_ |