// 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. // This file contains utility functions for dealing with the local // filesystem. #ifndef BASE_FILES_FILE_UTIL_H_ #define BASE_FILES_FILE_UTIL_H_ #include #include #include #include #include #include #include "base/base_export.h" #include "base/callback.h" #include "base/containers/span.h" #include "base/files/file.h" #include "base/files/file_path.h" #include "base/files/scoped_file.h" #include "build/build_config.h" #if BUILDFLAG(IS_WIN) #include "base/win/windows_types.h" #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) #include #include #include "base/posix/eintr_wrapper.h" #endif namespace base { class Environment; class Time; //----------------------------------------------------------------------------- // Functions that involve filesystem access or modification: // Returns an absolute version of a relative path. Returns an empty path on // error. On POSIX, this function fails if the path does not exist. This // function can result in I/O so it can be slow. BASE_EXPORT FilePath MakeAbsoluteFilePath(const FilePath& input); // Returns the total number of bytes used by all the files under |root_path|. // If the path does not exist the function returns 0. // // This function is implemented using the FileEnumerator class so it is not // particularly speedy on any platform. BASE_EXPORT int64_t ComputeDirectorySize(const FilePath& root_path); // Deletes the given path, whether it's a file or a directory. // If it's a directory, it's perfectly happy to delete all of the directory's // contents, but it will not recursively delete subdirectories and their // contents. // Returns true if successful, false otherwise. It is considered successful to // attempt to delete a file that does not exist. // // In POSIX environment and if |path| is a symbolic link, this deletes only // the symlink. (even if the symlink points to a non-existent file) BASE_EXPORT bool DeleteFile(const FilePath& path); // Deletes the given path, whether it's a file or a directory. // If it's a directory, it's perfectly happy to delete all of the // directory's contents, including subdirectories and their contents. // Returns true if successful, false otherwise. It is considered successful // to attempt to delete a file that does not exist. // // In POSIX environment and if |path| is a symbolic link, this deletes only // the symlink. (even if the symlink points to a non-existent file) // // WARNING: USING THIS EQUIVALENT TO "rm -rf", SO USE WITH CAUTION. BASE_EXPORT bool DeletePathRecursively(const FilePath& path); // Returns a closure that, when run on any sequence that allows blocking calls, // will kick off a potentially asynchronous operation to delete `path`, whose // behavior is similar to `DeleteFile()` and `DeletePathRecursively()` // respectively. // // In contrast to `DeleteFile()` and `DeletePathRecursively()`, the thread pool // may be used in case retries are needed. On Windows, in particular, retries // will be attempted for some time to allow other programs (e.g., anti-virus // scanners or malware) to close any open handles to `path` or its contents. If // `reply_callback` is not null, it will be posted to the caller's sequence with // true if `path` was fully deleted or false otherwise. // // WARNING: It is NOT safe to use `path` until `reply_callback` is run, as the // retry task may still be actively trying to delete it. BASE_EXPORT OnceClosure GetDeleteFileCallback(const FilePath& path, OnceCallback reply_callback = {}); BASE_EXPORT OnceClosure GetDeletePathRecursivelyCallback(const FilePath& path, OnceCallback reply_callback = {}); #if BUILDFLAG(IS_WIN) // Schedules to delete the given path, whether it's a file or a directory, until // the operating system is restarted. // Note: // 1) The file/directory to be deleted should exist in a temp folder. // 2) The directory to be deleted must be empty. BASE_EXPORT bool DeleteFileAfterReboot(const FilePath& path); #endif // Moves the given path, whether it's a file or a directory. // If a simple rename is not possible, such as in the case where the paths are // on different volumes, this will attempt to copy and delete. Returns // true for success. // This function fails if either path contains traversal components ('..'). BASE_EXPORT bool Move(const FilePath& from_path, const FilePath& to_path); // Renames file |from_path| to |to_path|. Both paths must be on the same // volume, or the function will fail. Destination file will be created // if it doesn't exist. Prefer this function over Move when dealing with // temporary files. On Windows it preserves attributes of the target file. // Returns true on success, leaving *error unchanged. // Returns false on failure and sets *error appropriately, if it is non-NULL. BASE_EXPORT bool ReplaceFile(const FilePath& from_path, const FilePath& to_path, File::Error* error); // Copies a single file. Use CopyDirectory() to copy directories. // This function fails if either path contains traversal components ('..'). // This function also fails if |to_path| is a directory. // // On POSIX, if |to_path| is a symlink, CopyFile() will follow the symlink. This // may have security implications. Use with care. // // If |to_path| already exists and is a regular file, it will be overwritten, // though its permissions will stay the same. // // If |to_path| does not exist, it will be created. The new file's permissions // varies per platform: // // - This function keeps the metadata on Windows. The read only bit is not kept. // - On Mac and iOS, |to_path| retains |from_path|'s permissions, except user // read/write permissions are always set. // - On Linux and Android, |to_path| has user read/write permissions only. i.e. // Always 0600. // - On ChromeOS, |to_path| has user read/write permissions and group/others // read permissions. i.e. Always 0644. BASE_EXPORT bool CopyFile(const FilePath& from_path, const FilePath& to_path); // Copies the contents of one file into another. // The files are taken as is: the copy is done starting from the current offset // of |infile| until the end of |infile| is reached, into the current offset of // |outfile|. BASE_EXPORT bool CopyFileContents(File& infile, File& outfile); // Copies the given path, and optionally all subdirectories and their contents // as well. // // If there are files existing under to_path, always overwrite. Returns true // if successful, false otherwise. Wildcards on the names are not supported. // // This function has the same metadata behavior as CopyFile(). // // If you only need to copy a file use CopyFile, it's faster. BASE_EXPORT bool CopyDirectory(const FilePath& from_path, const FilePath& to_path, bool recursive); // Like CopyDirectory() except trying to overwrite an existing file will not // work and will return false. BASE_EXPORT bool CopyDirectoryExcl(const FilePath& from_path, const FilePath& to_path, bool recursive); // Returns true if the given path exists on the local filesystem, // false otherwise. BASE_EXPORT bool PathExists(const FilePath& path); // Returns true if the given path is readable by the user, false otherwise. BASE_EXPORT bool PathIsReadable(const FilePath& path); // Returns true if the given path is writable by the user, false otherwise. BASE_EXPORT bool PathIsWritable(const FilePath& path); // Returns true if the given path exists and is a directory, false otherwise. BASE_EXPORT bool DirectoryExists(const FilePath& path); // Returns true if the contents of the two files given are equal, false // otherwise. If either file can't be read, returns false. BASE_EXPORT bool ContentsEqual(const FilePath& filename1, const FilePath& filename2); // Returns true if the contents of the two text files given are equal, false // otherwise. This routine treats "\r\n" and "\n" as equivalent. BASE_EXPORT bool TextContentsEqual(const FilePath& filename1, const FilePath& filename2); // Reads the file at |path| into |contents| and returns true on success and // false on error. For security reasons, a |path| containing path traversal // components ('..') is treated as a read error and |contents| is set to empty. // In case of I/O error, |contents| holds the data that could be read from the // file before the error occurred. // |contents| may be NULL, in which case this function is useful for its side // effect of priming the disk cache (could be used for unit tests). BASE_EXPORT bool ReadFileToString(const FilePath& path, std::string* contents); // Reads the file at |path| into |contents| and returns true on success and // false on error. For security reasons, a |path| containing path traversal // components ('..') is treated as a read error and |contents| is set to empty. // In case of I/O error, |contents| holds the data that could be read from the // file before the error occurred. When the file size exceeds |max_size|, the // function returns false with |contents| holding the file truncated to // |max_size|. // |contents| may be NULL, in which case this function is useful for its side // effect of priming the disk cache (could be used for unit tests). BASE_EXPORT bool ReadFileToStringWithMaxSize(const FilePath& path, std::string* contents, size_t max_size); // As ReadFileToString, but reading from an open stream after seeking to its // start (if supported by the stream). This can also be used to read the whole // file from a file descriptor by converting the file descriptor into a stream // by using base::FileToFILE() before calling this function. BASE_EXPORT bool ReadStreamToString(FILE* stream, std::string* contents); // As ReadFileToStringWithMaxSize, but reading from an open stream after seeking // to its start (if supported by the stream). BASE_EXPORT bool ReadStreamToStringWithMaxSize(FILE* stream, size_t max_size, std::string* contents); #if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) // Read exactly |bytes| bytes from file descriptor |fd|, storing the result // in |buffer|. This function is protected against EINTR and partial reads. // Returns true iff |bytes| bytes have been successfully read from |fd|. BASE_EXPORT bool ReadFromFD(int fd, char* buffer, size_t bytes); // Performs the same function as CreateAndOpenTemporaryStreamInDir(), but // returns the file-descriptor wrapped in a ScopedFD, rather than the stream // wrapped in a ScopedFILE. BASE_EXPORT ScopedFD CreateAndOpenFdForTemporaryFileInDir(const FilePath& dir, FilePath* path); #endif // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) #if BUILDFLAG(IS_POSIX) // ReadFileToStringNonBlocking is identical to ReadFileToString except it // guarantees that it will not block. This guarantee is provided on POSIX by // opening the file as O_NONBLOCK. This variant should only be used on files // which are guaranteed not to block (such as kernel files). Or in situations // where a partial read would be acceptable because the backing store returned // EWOULDBLOCK. BASE_EXPORT bool ReadFileToStringNonBlocking(const base::FilePath& file, std::string* ret); // Creates a symbolic link at |symlink| pointing to |target|. Returns // false on failure. BASE_EXPORT bool CreateSymbolicLink(const FilePath& target, const FilePath& symlink); // Reads the given |symlink| and returns where it points to in |target|. // Returns false upon failure. BASE_EXPORT bool ReadSymbolicLink(const FilePath& symlink, FilePath* target); // Bits and masks of the file permission. enum FilePermissionBits { FILE_PERMISSION_MASK = S_IRWXU | S_IRWXG | S_IRWXO, FILE_PERMISSION_USER_MASK = S_IRWXU, FILE_PERMISSION_GROUP_MASK = S_IRWXG, FILE_PERMISSION_OTHERS_MASK = S_IRWXO, FILE_PERMISSION_READ_BY_USER = S_IRUSR, FILE_PERMISSION_WRITE_BY_USER = S_IWUSR, FILE_PERMISSION_EXECUTE_BY_USER = S_IXUSR, FILE_PERMISSION_READ_BY_GROUP = S_IRGRP, FILE_PERMISSION_WRITE_BY_GROUP = S_IWGRP, FILE_PERMISSION_EXECUTE_BY_GROUP = S_IXGRP, FILE_PERMISSION_READ_BY_OTHERS = S_IROTH, FILE_PERMISSION_WRITE_BY_OTHERS = S_IWOTH, FILE_PERMISSION_EXECUTE_BY_OTHERS = S_IXOTH, }; // Reads the permission of the given |path|, storing the file permission // bits in |mode|. If |path| is symbolic link, |mode| is the permission of // a file which the symlink points to. BASE_EXPORT bool GetPosixFilePermissions(const FilePath& path, int* mode); // Sets the permission of the given |path|. If |path| is symbolic link, sets // the permission of a file which the symlink points to. BASE_EXPORT bool SetPosixFilePermissions(const FilePath& path, int mode); // Returns true iff |executable| can be found in any directory specified by the // environment variable in |env|. BASE_EXPORT bool ExecutableExistsInPath(Environment* env, const FilePath::StringType& executable); #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_AIX) // Determine if files under a given |path| can be mapped and then mprotect'd // PROT_EXEC. This depends on the mount options used for |path|, which vary // among different Linux distributions and possibly local configuration. It also // depends on details of kernel--ChromeOS uses the noexec option for /dev/shm // but its kernel allows mprotect with PROT_EXEC anyway. BASE_EXPORT bool IsPathExecutable(const FilePath& path); #endif // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_AIX) #endif // BUILDFLAG(IS_POSIX) // Returns true if the given directory is empty BASE_EXPORT bool IsDirectoryEmpty(const FilePath& dir_path); // Get the temporary directory provided by the system. // // WARNING: In general, you should use CreateTemporaryFile variants below // instead of this function. Those variants will ensure that the proper // permissions are set so that other users on the system can't edit them while // they're open (which can lead to security issues). BASE_EXPORT bool GetTempDir(FilePath* path); // Get the home directory. This is more complicated than just getenv("HOME") // as it knows to fall back on getpwent() etc. // // You should not generally call this directly. Instead use DIR_HOME with the // path service which will use this function but cache the value. // Path service may also override DIR_HOME. BASE_EXPORT FilePath GetHomeDir(); // Returns a new temporary file in |dir| with a unique name. The file is opened // for exclusive read, write, and delete access (note: exclusivity is unique to // Windows). On Windows, the returned file supports File::DeleteOnClose. // On success, |temp_file| is populated with the full path to the created file. BASE_EXPORT File CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* temp_file); // Creates a temporary file. The full path is placed in |path|, and the // function returns true if was successful in creating the file. The file will // be empty and all handles closed after this function returns. BASE_EXPORT bool CreateTemporaryFile(FilePath* path); // Same as CreateTemporaryFile but the file is created in |dir|. BASE_EXPORT bool CreateTemporaryFileInDir(const FilePath& dir, FilePath* temp_file); // Returns the file name for a temporary file by using a platform-specific // naming scheme that incorporates |identifier|. BASE_EXPORT FilePath FormatTemporaryFileName(FilePath::StringPieceType identifier); // Create and open a temporary file stream for exclusive read, write, and delete // access (note: exclusivity is unique to Windows). The full path is placed in // |path|. Returns the opened file stream, or null in case of error. BASE_EXPORT ScopedFILE CreateAndOpenTemporaryStream(FilePath* path); // Similar to CreateAndOpenTemporaryStream, but the file is created in |dir|. BASE_EXPORT ScopedFILE CreateAndOpenTemporaryStreamInDir(const FilePath& dir, FilePath* path); // Do NOT USE in new code. Use ScopedTempDir instead. // TODO(crbug.com/561597) Remove existing usage and make this an implementation // detail inside ScopedTempDir. // // Create a new directory. If prefix is provided, the new directory name is in // the format of prefixyyyy. // NOTE: prefix is ignored in the POSIX implementation. // If success, return true and output the full path of the directory created. BASE_EXPORT bool CreateNewTempDirectory(const FilePath::StringType& prefix, FilePath* new_temp_path); // Create a directory within another directory. // Extra characters will be appended to |prefix| to ensure that the // new directory does not have the same name as an existing directory. BASE_EXPORT bool CreateTemporaryDirInDir(const FilePath& base_dir, const FilePath::StringType& prefix, FilePath* new_dir); // Creates a directory, as well as creating any parent directories, if they // don't exist. Returns 'true' on successful creation, or if the directory // already exists. The directory is only readable by the current user. // Returns true on success, leaving *error unchanged. // Returns false on failure and sets *error appropriately, if it is non-NULL. BASE_EXPORT bool CreateDirectoryAndGetError(const FilePath& full_path, File::Error* error); // Backward-compatible convenience method for the above. BASE_EXPORT bool CreateDirectory(const FilePath& full_path); // Returns the file size. Returns true on success. BASE_EXPORT bool GetFileSize(const FilePath& file_path, int64_t* file_size); // Sets |real_path| to |path| with symbolic links and junctions expanded. // On windows, make sure the path starts with a lettered drive. // |path| must reference a file. Function will fail if |path| points to // a directory or to a nonexistent path. On windows, this function will // fail if |real_path| would be longer than MAX_PATH characters. BASE_EXPORT bool NormalizeFilePath(const FilePath& path, FilePath* real_path); #if BUILDFLAG(IS_WIN) // Given a path in NT native form ("\Device\HarddiskVolumeXX\..."), // return in |drive_letter_path| the equivalent path that starts with // a drive letter ("C:\..."). Return false if no such path exists. BASE_EXPORT bool DevicePathToDriveLetterPath(const FilePath& device_path, FilePath* drive_letter_path); // Method that wraps the win32 GetLongPathName API, normalizing the specified // path to its long form. An example where this is needed is when comparing // temp file paths. If a username isn't a valid 8.3 short file name (even just a // lengthy name like "user with long name"), Windows will set the TMP and TEMP // environment variables to be 8.3 paths. ::GetTempPath (called in // base::GetTempDir) just uses the value specified by TMP or TEMP, and so can // return a short path. Returns an empty path on error. BASE_EXPORT FilePath MakeLongFilePath(const FilePath& input); // Creates a hard link named |to_file| to the file |from_file|. Both paths // must be on the same volume, and |from_file| may not name a directory. // Returns true if the hard link is created, false if it fails. BASE_EXPORT bool CreateWinHardLink(const FilePath& to_file, const FilePath& from_file); #endif // This function will return if the given file is a symlink or not. BASE_EXPORT bool IsLink(const FilePath& file_path); // Returns information about the given file path. BASE_EXPORT bool GetFileInfo(const FilePath& file_path, File::Info* info); // Sets the time of the last access and the time of the last modification. BASE_EXPORT bool TouchFile(const FilePath& path, const Time& last_accessed, const Time& last_modified); // Wrapper for fopen-like calls. Returns non-NULL FILE* on success. The // underlying file descriptor (POSIX) or handle (Windows) is unconditionally // configured to not be propagated to child processes. BASE_EXPORT FILE* OpenFile(const FilePath& filename, const char* mode); // Closes file opened by OpenFile. Returns true on success. BASE_EXPORT bool CloseFile(FILE* file); // Associates a standard FILE stream with an existing File. Note that this // functions take ownership of the existing File. BASE_EXPORT FILE* FileToFILE(File file, const char* mode); // Returns a new handle to the file underlying |file_stream|. BASE_EXPORT File FILEToFile(FILE* file_stream); // Truncates an open file to end at the location of the current file pointer. // This is a cross-platform analog to Windows' SetEndOfFile() function. BASE_EXPORT bool TruncateFile(FILE* file); // Reads at most the given number of bytes from the file into the buffer. // Returns the number of read bytes, or -1 on error. BASE_EXPORT int ReadFile(const FilePath& filename, char* data, int max_size); // Writes the given buffer into the file, overwriting any data that was // previously there. Returns the number of bytes written, or -1 on error. // If file doesn't exist, it gets created with read/write permissions for all. // Note that the other variants of WriteFile() below may be easier to use. BASE_EXPORT int WriteFile(const FilePath& filename, const char* data, int size); // Writes |data| into the file, overwriting any data that was previously there. // Returns true if and only if all of |data| was written. If the file does not // exist, it gets created with read/write permissions for all. BASE_EXPORT bool WriteFile(const FilePath& filename, span data); // Another WriteFile() variant that takes a StringPiece so callers don't have to // do manual conversions from a char span to a uint8_t span. BASE_EXPORT bool WriteFile(const FilePath& filename, StringPiece data); #if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) // Appends |data| to |fd|. Does not close |fd| when done. Returns true iff all // of |data| were written to |fd|. BASE_EXPORT bool WriteFileDescriptor(int fd, span data); // WriteFileDescriptor() variant that takes a StringPiece so callers don't have // to do manual conversions from a char span to a uint8_t span. BASE_EXPORT bool WriteFileDescriptor(int fd, StringPiece data); // Allocates disk space for the file referred to by |fd| for the byte range // starting at |offset| and continuing for |size| bytes. The file size will be // changed if |offset|+|len| is greater than the file size. Zeros will fill the // new space. // After a successful call, subsequent writes into the specified range are // guaranteed not to fail because of lack of disk space. BASE_EXPORT bool AllocateFileRegion(File* file, int64_t offset, size_t size); #endif // Appends |data| to |filename|. Returns true iff |data| were written to // |filename|. BASE_EXPORT bool AppendToFile(const FilePath& filename, span data); // AppendToFile() variant that takes a StringPiece so callers don't have to do // manual conversions from a char span to a uint8_t span. BASE_EXPORT bool AppendToFile(const FilePath& filename, StringPiece data); // Gets the current working directory for the process. BASE_EXPORT bool GetCurrentDirectory(FilePath* path); // Sets the current working directory for the process. BASE_EXPORT bool SetCurrentDirectory(const FilePath& path); // The largest value attempted by GetUniquePath{Number,}. enum { kMaxUniqueFiles = 100 }; // Returns the number N that makes |path| unique when formatted as " (N)" in a // suffix to its basename before any file extension, where N is a number between // 1 and 100 (inclusive). Returns 0 if |path| does not exist (meaning that it is // unique as-is), or -1 if no such number can be found. BASE_EXPORT int GetUniquePathNumber(const FilePath& path); // Returns |path| if it does not exist. Otherwise, returns |path| with the // suffix " (N)" appended to its basename before any file extension, where N is // a number between 1 and 100 (inclusive). Returns an empty path if no such // number can be found. BASE_EXPORT FilePath GetUniquePath(const FilePath& path); // Sets the given |fd| to non-blocking mode. // Returns true if it was able to set it in the non-blocking mode, otherwise // false. BASE_EXPORT bool SetNonBlocking(int fd); // Hints the OS to prefetch the first |max_bytes| of |file_path| into its cache. // // If called at the appropriate time, this can reduce the latency incurred by // feature code that needs to read the file. // // |max_bytes| specifies how many bytes should be pre-fetched. It may exceed the // file's size. Passing in std::numeric_limits::max() is a convenient // way to get the entire file pre-fetched. // // |is_executable| specifies whether the file is to be prefetched as // executable code or as data. Windows treats the file backed pages in RAM // differently, and specifying the wrong value results in two copies in RAM. // // Returns true if at least part of the requested range was successfully // prefetched. // // Calling this before using ::LoadLibrary() on Windows is more efficient memory // wise, but we must be sure no other threads try to LoadLibrary() the file // while we are doing the mapping and prefetching, or the process will get a // private copy of the DLL via COW. BASE_EXPORT bool PreReadFile( const FilePath& file_path, bool is_executable, int64_t max_bytes = std::numeric_limits::max()); #if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) // Creates a pipe. Returns true on success, otherwise false. // On success, |read_fd| will be set to the fd of the read side, and // |write_fd| will be set to the one of write side. If |non_blocking| // is set the pipe will be created with O_NONBLOCK|O_CLOEXEC flags set // otherwise flag is set to zero (default). BASE_EXPORT bool CreatePipe(ScopedFD* read_fd, ScopedFD* write_fd, bool non_blocking = false); // Creates a non-blocking, close-on-exec pipe. // This creates a non-blocking pipe that is not intended to be shared with any // child process. This will be done atomically if the operating system supports // it. Returns true if it was able to create the pipe, otherwise false. BASE_EXPORT bool CreateLocalNonBlockingPipe(int fds[2]); // Sets the given |fd| to close-on-exec mode. // Returns true if it was able to set it in the close-on-exec mode, otherwise // false. BASE_EXPORT bool SetCloseOnExec(int fd); #endif // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) #if BUILDFLAG(IS_MAC) // Test that |path| can only be changed by a given user and members of // a given set of groups. // Specifically, test that all parts of |path| under (and including) |base|: // * Exist. // * Are owned by a specific user. // * Are not writable by all users. // * Are owned by a member of a given set of groups, or are not writable by // their group. // * Are not symbolic links. // This is useful for checking that a config file is administrator-controlled. // |base| must contain |path|. BASE_EXPORT bool VerifyPathControlledByUser(const base::FilePath& base, const base::FilePath& path, uid_t owner_uid, const std::set& group_gids); // Is |path| writable only by a user with administrator privileges? // This function uses Mac OS conventions. The super user is assumed to have // uid 0, and the administrator group is assumed to be named "admin". // Testing that |path|, and every parent directory including the root of // the filesystem, are owned by the superuser, controlled by the group // "admin", are not writable by all users, and contain no symbolic links. // Will return false if |path| does not exist. BASE_EXPORT bool VerifyPathControlledByAdmin(const base::FilePath& path); #endif // BUILDFLAG(IS_MAC) // Returns the maximum length of path component on the volume containing // the directory |path|, in the number of FilePath::CharType, or -1 on failure. BASE_EXPORT int GetMaximumPathComponentLength(const base::FilePath& path); #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_AIX) // Broad categories of file systems as returned by statfs() on Linux. enum FileSystemType { FILE_SYSTEM_UNKNOWN, // statfs failed. FILE_SYSTEM_0, // statfs.f_type == 0 means unknown, may indicate AFS. FILE_SYSTEM_ORDINARY, // on-disk filesystem like ext2 FILE_SYSTEM_NFS, FILE_SYSTEM_SMB, FILE_SYSTEM_CODA, FILE_SYSTEM_MEMORY, // in-memory file system FILE_SYSTEM_CGROUP, // cgroup control. FILE_SYSTEM_OTHER, // any other value. FILE_SYSTEM_TYPE_COUNT }; // Attempts determine the FileSystemType for |path|. // Returns false if |path| doesn't exist. BASE_EXPORT bool GetFileSystemType(const FilePath& path, FileSystemType* type); #endif #if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) // Get a temporary directory for shared memory files. The directory may depend // on whether the destination is intended for executable files, which in turn // depends on how /dev/shmem was mounted. As a result, you must supply whether // you intend to create executable shmem segments so this function can find // an appropriate location. BASE_EXPORT bool GetShmemTempDir(bool executable, FilePath* path); #endif // Internal -------------------------------------------------------------------- namespace internal { // Same as Move but allows paths with traversal components. // Use only with extreme care. BASE_EXPORT bool MoveUnsafe(const FilePath& from_path, const FilePath& to_path); #if BUILDFLAG(IS_WIN) // Copy from_path to to_path recursively and then delete from_path recursively. // Returns true if all operations succeed. // This function simulates Move(), but unlike Move() it works across volumes. // This function is not transactional. BASE_EXPORT bool CopyAndDeleteDirectory(const FilePath& from_path, const FilePath& to_path); #endif // BUILDFLAG(IS_WIN) #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID) // CopyFileContentsWithSendfile will use the sendfile(2) syscall to perform a // file copy without moving the data between kernel and userspace. This is much // more efficient than sequences of read(2)/write(2) calls. The |retry_slow| // parameter instructs the caller that it should try to fall back to a normal // sequences of read(2)/write(2) syscalls. // // The input file |infile| must be opened for reading and the output file // |outfile| must be opened for writing. BASE_EXPORT bool CopyFileContentsWithSendfile(File& infile, File& outfile, bool& retry_slow); #endif // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || // BUILDFLAG(IS_ANDROID) // Used by PreReadFile() when no kernel support for prefetching is available. bool PreReadFileSlow(const FilePath& file_path, int64_t max_bytes); } // namespace internal } // namespace base #endif // BASE_FILES_FILE_UTIL_H_