1// Copyright (c) 2011 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5// This file contains utility functions for dealing with the local 6// filesystem. 7 8#ifndef BASE_FILE_UTIL_H_ 9#define BASE_FILE_UTIL_H_ 10#pragma once 11 12#include "build/build_config.h" 13 14#if defined(OS_WIN) 15#include <windows.h> 16#if defined(UNIT_TEST) 17#include <aclapi.h> 18#endif 19#elif defined(OS_POSIX) 20#include <sys/stat.h> 21#endif 22 23#include <stdio.h> 24 25#include <stack> 26#include <string> 27#include <vector> 28 29#include "base/base_api.h" 30#include "base/basictypes.h" 31#include "base/file_path.h" 32#include "base/memory/scoped_ptr.h" 33#include "base/platform_file.h" 34#include "base/string16.h" 35 36#if defined(OS_POSIX) 37#include "base/eintr_wrapper.h" 38#include "base/file_descriptor_posix.h" 39#include "base/logging.h" 40#endif 41 42namespace base { 43class Time; 44} 45 46namespace file_util { 47 48//----------------------------------------------------------------------------- 49// Functions that operate purely on a path string w/o touching the filesystem: 50 51// Returns true if the given path ends with a path separator character. 52BASE_API bool EndsWithSeparator(const FilePath& path); 53 54// Makes sure that |path| ends with a separator IFF path is a directory that 55// exists. Returns true if |path| is an existing directory, false otherwise. 56BASE_API bool EnsureEndsWithSeparator(FilePath* path); 57 58// Convert provided relative path into an absolute path. Returns false on 59// error. On POSIX, this function fails if the path does not exist. 60BASE_API bool AbsolutePath(FilePath* path); 61 62// Returns true if |parent| contains |child|. Both paths are converted to 63// absolute paths before doing the comparison. 64BASE_API bool ContainsPath(const FilePath& parent, const FilePath& child); 65 66//----------------------------------------------------------------------------- 67// Functions that involve filesystem access or modification: 68 69// Returns the number of files matching the current path that were 70// created on or after the given |file_time|. Doesn't count ".." or ".". 71// 72// Note for POSIX environments: a file created before |file_time| 73// can be mis-detected as a newer file due to low precision of 74// timestmap of file creation time. If you need to avoid such 75// mis-detection perfectly, you should wait one second before 76// obtaining |file_time|. 77BASE_API int CountFilesCreatedAfter(const FilePath& path, 78 const base::Time& file_time); 79 80// Returns the total number of bytes used by all the files under |root_path|. 81// If the path does not exist the function returns 0. 82// 83// This function is implemented using the FileEnumerator class so it is not 84// particularly speedy in any platform. 85BASE_API int64 ComputeDirectorySize(const FilePath& root_path); 86 87// Returns the total number of bytes used by all files matching the provided 88// |pattern|, on this |directory| (without recursion). If the path does not 89// exist the function returns 0. 90// 91// This function is implemented using the FileEnumerator class so it is not 92// particularly speedy in any platform. 93BASE_API int64 ComputeFilesSize(const FilePath& directory, 94 const FilePath::StringType& pattern); 95 96// Deletes the given path, whether it's a file or a directory. 97// If it's a directory, it's perfectly happy to delete all of the 98// directory's contents. Passing true to recursive deletes 99// subdirectories and their contents as well. 100// Returns true if successful, false otherwise. 101// 102// WARNING: USING THIS WITH recursive==true IS EQUIVALENT 103// TO "rm -rf", SO USE WITH CAUTION. 104BASE_API bool Delete(const FilePath& path, bool recursive); 105 106#if defined(OS_WIN) 107// Schedules to delete the given path, whether it's a file or a directory, until 108// the operating system is restarted. 109// Note: 110// 1) The file/directory to be deleted should exist in a temp folder. 111// 2) The directory to be deleted must be empty. 112BASE_API bool DeleteAfterReboot(const FilePath& path); 113#endif 114 115// Moves the given path, whether it's a file or a directory. 116// If a simple rename is not possible, such as in the case where the paths are 117// on different volumes, this will attempt to copy and delete. Returns 118// true for success. 119BASE_API bool Move(const FilePath& from_path, const FilePath& to_path); 120 121// Renames file |from_path| to |to_path|. Both paths must be on the same 122// volume, or the function will fail. Destination file will be created 123// if it doesn't exist. Prefer this function over Move when dealing with 124// temporary files. On Windows it preserves attributes of the target file. 125// Returns true on success. 126BASE_API bool ReplaceFile(const FilePath& from_path, const FilePath& to_path); 127 128// Copies a single file. Use CopyDirectory to copy directories. 129BASE_API bool CopyFile(const FilePath& from_path, const FilePath& to_path); 130 131// Copies the given path, and optionally all subdirectories and their contents 132// as well. 133// If there are files existing under to_path, always overwrite. 134// Returns true if successful, false otherwise. 135// Don't use wildcards on the names, it may stop working without notice. 136// 137// If you only need to copy a file use CopyFile, it's faster. 138BASE_API bool CopyDirectory(const FilePath& from_path, const FilePath& to_path, 139 bool recursive); 140 141// Returns true if the given path exists on the local filesystem, 142// false otherwise. 143BASE_API bool PathExists(const FilePath& path); 144 145// Returns true if the given path is writable by the user, false otherwise. 146BASE_API bool PathIsWritable(const FilePath& path); 147 148// Returns true if the given path exists and is a directory, false otherwise. 149BASE_API bool DirectoryExists(const FilePath& path); 150 151#if defined(OS_WIN) 152// Gets the creation time of the given file (expressed in the local timezone), 153// and returns it via the creation_time parameter. Returns true if successful, 154// false otherwise. 155BASE_API bool GetFileCreationLocalTime(const std::wstring& filename, 156 LPSYSTEMTIME creation_time); 157 158// Same as above, but takes a previously-opened file handle instead of a name. 159BASE_API bool GetFileCreationLocalTimeFromHandle(HANDLE file_handle, 160 LPSYSTEMTIME creation_time); 161#endif // defined(OS_WIN) 162 163// Returns true if the contents of the two files given are equal, false 164// otherwise. If either file can't be read, returns false. 165BASE_API bool ContentsEqual(const FilePath& filename1, 166 const FilePath& filename2); 167 168// Returns true if the contents of the two text files given are equal, false 169// otherwise. This routine treats "\r\n" and "\n" as equivalent. 170BASE_API bool TextContentsEqual(const FilePath& filename1, 171 const FilePath& filename2); 172 173// Read the file at |path| into |contents|, returning true on success. 174// |contents| may be NULL, in which case this function is useful for its 175// side effect of priming the disk cache. 176// Useful for unit tests. 177BASE_API bool ReadFileToString(const FilePath& path, std::string* contents); 178 179#if defined(OS_POSIX) 180// Read exactly |bytes| bytes from file descriptor |fd|, storing the result 181// in |buffer|. This function is protected against EINTR and partial reads. 182// Returns true iff |bytes| bytes have been successfuly read from |fd|. 183bool ReadFromFD(int fd, char* buffer, size_t bytes); 184 185// Creates a symbolic link at |symlink| pointing to |target|. Returns 186// false on failure. 187bool CreateSymbolicLink(const FilePath& target, const FilePath& symlink); 188 189// Reads the given |symlink| and returns where it points to in |target|. 190// Returns false upon failure. 191bool ReadSymbolicLink(const FilePath& symlink, FilePath* target); 192#endif // defined(OS_POSIX) 193 194#if defined(OS_WIN) 195// Resolve Windows shortcut (.LNK file) 196// This methods tries to resolve a shortcut .LNK file. If the |path| is valid 197// returns true and puts the target into the |path|, otherwise returns 198// false leaving the path as it is. 199BASE_API bool ResolveShortcut(FilePath* path); 200 201// Create a Windows shortcut (.LNK file) 202// This method creates a shortcut link using the information given. Ensure 203// you have initialized COM before calling into this function. 'source' 204// and 'destination' parameters are required, everything else can be NULL. 205// 'source' is the existing file, 'destination' is the new link file to be 206// created; for best results pass the filename with the .lnk extension. 207// The 'icon' can specify a dll or exe in which case the icon index is the 208// resource id. 'app_id' is the app model id for the shortcut on Win7. 209// Note that if the shortcut exists it will overwrite it. 210BASE_API bool CreateShortcutLink(const wchar_t *source, 211 const wchar_t *destination, 212 const wchar_t *working_dir, 213 const wchar_t *arguments, 214 const wchar_t *description, 215 const wchar_t *icon, 216 int icon_index, 217 const wchar_t* app_id); 218 219// Update a Windows shortcut (.LNK file). This method assumes the shortcut 220// link already exists (otherwise false is returned). Ensure you have 221// initialized COM before calling into this function. Only 'destination' 222// parameter is required, everything else can be NULL (but if everything else 223// is NULL no changes are made to the shortcut). 'destination' is the link 224// file to be updated. 'app_id' is the app model id for the shortcut on Win7. 225// For best results pass the filename with the .lnk extension. 226BASE_API bool UpdateShortcutLink(const wchar_t *source, 227 const wchar_t *destination, 228 const wchar_t *working_dir, 229 const wchar_t *arguments, 230 const wchar_t *description, 231 const wchar_t *icon, 232 int icon_index, 233 const wchar_t* app_id); 234 235// Pins a shortcut to the Windows 7 taskbar. The shortcut file must already 236// exist and be a shortcut that points to an executable. 237BASE_API bool TaskbarPinShortcutLink(const wchar_t* shortcut); 238 239// Unpins a shortcut from the Windows 7 taskbar. The shortcut must exist and 240// already be pinned to the taskbar. 241BASE_API bool TaskbarUnpinShortcutLink(const wchar_t* shortcut); 242 243// Copy from_path to to_path recursively and then delete from_path recursively. 244// Returns true if all operations succeed. 245// This function simulates Move(), but unlike Move() it works across volumes. 246// This fuction is not transactional. 247BASE_API bool CopyAndDeleteDirectory(const FilePath& from_path, 248 const FilePath& to_path); 249#endif // defined(OS_WIN) 250 251// Return true if the given directory is empty 252BASE_API bool IsDirectoryEmpty(const FilePath& dir_path); 253 254// Get the temporary directory provided by the system. 255// WARNING: DON'T USE THIS. If you want to create a temporary file, use one of 256// the functions below. 257BASE_API bool GetTempDir(FilePath* path); 258// Get a temporary directory for shared memory files. 259// Only useful on POSIX; redirects to GetTempDir() on Windows. 260BASE_API bool GetShmemTempDir(FilePath* path); 261 262// Get the home directory. This is more complicated than just getenv("HOME") 263// as it knows to fall back on getpwent() etc. 264BASE_API FilePath GetHomeDir(); 265 266// Creates a temporary file. The full path is placed in |path|, and the 267// function returns true if was successful in creating the file. The file will 268// be empty and all handles closed after this function returns. 269BASE_API bool CreateTemporaryFile(FilePath* path); 270 271// Same as CreateTemporaryFile but the file is created in |dir|. 272BASE_API bool CreateTemporaryFileInDir(const FilePath& dir, 273 FilePath* temp_file); 274 275// Create and open a temporary file. File is opened for read/write. 276// The full path is placed in |path|. 277// Returns a handle to the opened file or NULL if an error occured. 278BASE_API FILE* CreateAndOpenTemporaryFile(FilePath* path); 279// Like above but for shmem files. Only useful for POSIX. 280BASE_API FILE* CreateAndOpenTemporaryShmemFile(FilePath* path); 281// Similar to CreateAndOpenTemporaryFile, but the file is created in |dir|. 282BASE_API FILE* CreateAndOpenTemporaryFileInDir(const FilePath& dir, 283 FilePath* path); 284 285// Create a new directory. If prefix is provided, the new directory name is in 286// the format of prefixyyyy. 287// NOTE: prefix is ignored in the POSIX implementation. 288// If success, return true and output the full path of the directory created. 289BASE_API bool CreateNewTempDirectory(const FilePath::StringType& prefix, 290 FilePath* new_temp_path); 291 292// Create a directory within another directory. 293// Extra characters will be appended to |prefix| to ensure that the 294// new directory does not have the same name as an existing directory. 295BASE_API bool CreateTemporaryDirInDir(const FilePath& base_dir, 296 const FilePath::StringType& prefix, 297 FilePath* new_dir); 298 299// Creates a directory, as well as creating any parent directories, if they 300// don't exist. Returns 'true' on successful creation, or if the directory 301// already exists. The directory is only readable by the current user. 302BASE_API bool CreateDirectory(const FilePath& full_path); 303 304// Returns the file size. Returns true on success. 305BASE_API bool GetFileSize(const FilePath& file_path, int64* file_size); 306 307// Returns true if the given path's base name is ".". 308BASE_API bool IsDot(const FilePath& path); 309 310// Returns true if the given path's base name is "..". 311BASE_API bool IsDotDot(const FilePath& path); 312 313// Sets |real_path| to |path| with symbolic links and junctions expanded. 314// On windows, make sure the path starts with a lettered drive. 315// |path| must reference a file. Function will fail if |path| points to 316// a directory or to a nonexistent path. On windows, this function will 317// fail if |path| is a junction or symlink that points to an empty file, 318// or if |real_path| would be longer than MAX_PATH characters. 319BASE_API bool NormalizeFilePath(const FilePath& path, FilePath* real_path); 320 321#if defined(OS_WIN) 322// Given an existing file in |path|, it returns in |real_path| the path 323// in the native NT format, of the form "\Device\HarddiskVolumeXX\..". 324// Returns false it it fails. Empty files cannot be resolved with this 325// function. 326BASE_API bool NormalizeToNativeFilePath(const FilePath& path, 327 FilePath* nt_path); 328#endif 329 330// Returns information about the given file path. 331BASE_API bool GetFileInfo(const FilePath& file_path, 332 base::PlatformFileInfo* info); 333 334// Sets the time of the last access and the time of the last modification. 335BASE_API bool TouchFile(const FilePath& path, 336 const base::Time& last_accessed, 337 const base::Time& last_modified); 338 339// Set the time of the last modification. Useful for unit tests. 340BASE_API bool SetLastModifiedTime(const FilePath& path, 341 const base::Time& last_modified); 342 343#if defined(OS_POSIX) 344// Store inode number of |path| in |inode|. Return true on success. 345bool GetInode(const FilePath& path, ino_t* inode); 346#endif 347 348// Wrapper for fopen-like calls. Returns non-NULL FILE* on success. 349BASE_API FILE* OpenFile(const FilePath& filename, const char* mode); 350 351// Closes file opened by OpenFile. Returns true on success. 352BASE_API bool CloseFile(FILE* file); 353 354// Truncates an open file to end at the location of the current file pointer. 355// This is a cross-platform analog to Windows' SetEndOfFile() function. 356BASE_API bool TruncateFile(FILE* file); 357 358// Reads the given number of bytes from the file into the buffer. Returns 359// the number of read bytes, or -1 on error. 360BASE_API int ReadFile(const FilePath& filename, char* data, int size); 361 362// Writes the given buffer into the file, overwriting any data that was 363// previously there. Returns the number of bytes written, or -1 on error. 364BASE_API int WriteFile(const FilePath& filename, const char* data, int size); 365#if defined(OS_POSIX) 366// Append the data to |fd|. Does not close |fd| when done. 367int WriteFileDescriptor(const int fd, const char* data, int size); 368#endif 369 370// Gets the current working directory for the process. 371BASE_API bool GetCurrentDirectory(FilePath* path); 372 373// Sets the current working directory for the process. 374BASE_API bool SetCurrentDirectory(const FilePath& path); 375 376// A class to handle auto-closing of FILE*'s. 377class ScopedFILEClose { 378 public: 379 inline void operator()(FILE* x) const { 380 if (x) { 381 fclose(x); 382 } 383 } 384}; 385 386typedef scoped_ptr_malloc<FILE, ScopedFILEClose> ScopedFILE; 387 388#if defined(OS_POSIX) 389// A class to handle auto-closing of FDs. 390class ScopedFDClose { 391 public: 392 inline void operator()(int* x) const { 393 if (x && *x >= 0) { 394 if (HANDLE_EINTR(close(*x)) < 0) 395 PLOG(ERROR) << "close"; 396 } 397 } 398}; 399 400typedef scoped_ptr_malloc<int, ScopedFDClose> ScopedFD; 401#endif // OS_POSIX 402 403// A class for enumerating the files in a provided path. The order of the 404// results is not guaranteed. 405// 406// DO NOT USE FROM THE MAIN THREAD of your application unless it is a test 407// program where latency does not matter. This class is blocking. 408class BASE_API FileEnumerator { 409 public: 410#if defined(OS_WIN) 411 typedef WIN32_FIND_DATA FindInfo; 412#elif defined(OS_POSIX) 413 typedef struct { 414 struct stat stat; 415 std::string filename; 416 } FindInfo; 417#endif 418 419 enum FILE_TYPE { 420 FILES = 1 << 0, 421 DIRECTORIES = 1 << 1, 422 INCLUDE_DOT_DOT = 1 << 2, 423#if defined(OS_POSIX) 424 SHOW_SYM_LINKS = 1 << 4, 425#endif 426 }; 427 428 // |root_path| is the starting directory to search for. It may or may not end 429 // in a slash. 430 // 431 // If |recursive| is true, this will enumerate all matches in any 432 // subdirectories matched as well. It does a breadth-first search, so all 433 // files in one directory will be returned before any files in a 434 // subdirectory. 435 // 436 // |file_type| specifies whether the enumerator should match files, 437 // directories, or both. 438 // 439 // |pattern| is an optional pattern for which files to match. This 440 // works like shell globbing. For example, "*.txt" or "Foo???.doc". 441 // However, be careful in specifying patterns that aren't cross platform 442 // since the underlying code uses OS-specific matching routines. In general, 443 // Windows matching is less featureful than others, so test there first. 444 // If unspecified, this will match all files. 445 // NOTE: the pattern only matches the contents of root_path, not files in 446 // recursive subdirectories. 447 // TODO(erikkay): Fix the pattern matching to work at all levels. 448 FileEnumerator(const FilePath& root_path, 449 bool recursive, 450 FileEnumerator::FILE_TYPE file_type); 451 FileEnumerator(const FilePath& root_path, 452 bool recursive, 453 FileEnumerator::FILE_TYPE file_type, 454 const FilePath::StringType& pattern); 455 ~FileEnumerator(); 456 457 // Returns an empty string if there are no more results. 458 FilePath Next(); 459 460 // Write the file info into |info|. 461 void GetFindInfo(FindInfo* info); 462 463 // Looks inside a FindInfo and determines if it's a directory. 464 static bool IsDirectory(const FindInfo& info); 465 466 static FilePath GetFilename(const FindInfo& find_info); 467 468 private: 469 // Returns true if the given path should be skipped in enumeration. 470 bool ShouldSkip(const FilePath& path); 471 472 473#if defined(OS_WIN) 474 // True when find_data_ is valid. 475 bool has_find_data_; 476 WIN32_FIND_DATA find_data_; 477 HANDLE find_handle_; 478#elif defined(OS_POSIX) 479 struct DirectoryEntryInfo { 480 FilePath filename; 481 struct stat stat; 482 }; 483 484 // Read the filenames in source into the vector of DirectoryEntryInfo's 485 static bool ReadDirectory(std::vector<DirectoryEntryInfo>* entries, 486 const FilePath& source, bool show_links); 487 488 // The files in the current directory 489 std::vector<DirectoryEntryInfo> directory_entries_; 490 491 // The next entry to use from the directory_entries_ vector 492 size_t current_directory_entry_; 493#endif 494 495 FilePath root_path_; 496 bool recursive_; 497 FILE_TYPE file_type_; 498 FilePath::StringType pattern_; // Empty when we want to find everything. 499 500 // A stack that keeps track of which subdirectories we still need to 501 // enumerate in the breadth-first search. 502 std::stack<FilePath> pending_paths_; 503 504 DISALLOW_COPY_AND_ASSIGN(FileEnumerator); 505}; 506 507class BASE_API MemoryMappedFile { 508 public: 509 // The default constructor sets all members to invalid/null values. 510 MemoryMappedFile(); 511 ~MemoryMappedFile(); 512 513 // Opens an existing file and maps it into memory. Access is restricted to 514 // read only. If this object already points to a valid memory mapped file 515 // then this method will fail and return false. If it cannot open the file, 516 // the file does not exist, or the memory mapping fails, it will return false. 517 // Later we may want to allow the user to specify access. 518 bool Initialize(const FilePath& file_name); 519 // As above, but works with an already-opened file. MemoryMappedFile will take 520 // ownership of |file| and close it when done. 521 bool Initialize(base::PlatformFile file); 522 523#if defined(OS_WIN) 524 // Opens an existing file and maps it as an image section. Please refer to 525 // the Initialize function above for additional information. 526 bool InitializeAsImageSection(const FilePath& file_name); 527#endif // OS_WIN 528 529 const uint8* data() const { return data_; } 530 size_t length() const { return length_; } 531 532 // Is file_ a valid file handle that points to an open, memory mapped file? 533 bool IsValid() const; 534 535 private: 536 // Open the given file and pass it to MapFileToMemoryInternal(). 537 bool MapFileToMemory(const FilePath& file_name); 538 539 // Map the file to memory, set data_ to that memory address. Return true on 540 // success, false on any kind of failure. This is a helper for Initialize(). 541 bool MapFileToMemoryInternal(); 542 543 // Closes all open handles. Later we may want to make this public. 544 void CloseHandles(); 545 546#if defined(OS_WIN) 547 // MapFileToMemoryInternal calls this function. It provides the ability to 548 // pass in flags which control the mapped section. 549 bool MapFileToMemoryInternalEx(int flags); 550 551 HANDLE file_mapping_; 552#endif 553 base::PlatformFile file_; 554 uint8* data_; 555 size_t length_; 556 557 DISALLOW_COPY_AND_ASSIGN(MemoryMappedFile); 558}; 559 560// Renames a file using the SHFileOperation API to ensure that the target file 561// gets the correct default security descriptor in the new path. 562BASE_API bool RenameFileAndResetSecurityDescriptor( 563 const FilePath& source_file_path, 564 const FilePath& target_file_path); 565 566// Returns whether the file has been modified since a particular date. 567BASE_API bool HasFileBeenModifiedSince( 568 const FileEnumerator::FindInfo& find_info, 569 const base::Time& cutoff_time); 570 571#ifdef UNIT_TEST 572 573inline bool MakeFileUnreadable(const FilePath& path) { 574#if defined(OS_POSIX) 575 struct stat stat_buf; 576 if (stat(path.value().c_str(), &stat_buf) != 0) 577 return false; 578 stat_buf.st_mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 579 580 return chmod(path.value().c_str(), stat_buf.st_mode) == 0; 581 582#elif defined(OS_WIN) 583 PACL old_dacl; 584 PSECURITY_DESCRIPTOR security_descriptor; 585 if (GetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()), 586 SE_FILE_OBJECT, 587 DACL_SECURITY_INFORMATION, NULL, NULL, &old_dacl, 588 NULL, &security_descriptor) != ERROR_SUCCESS) 589 return false; 590 591 // Deny Read access for the current user. 592 EXPLICIT_ACCESS change; 593 change.grfAccessPermissions = GENERIC_READ; 594 change.grfAccessMode = DENY_ACCESS; 595 change.grfInheritance = 0; 596 change.Trustee.pMultipleTrustee = NULL; 597 change.Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE; 598 change.Trustee.TrusteeForm = TRUSTEE_IS_NAME; 599 change.Trustee.TrusteeType = TRUSTEE_IS_USER; 600 change.Trustee.ptstrName = L"CURRENT_USER"; 601 602 PACL new_dacl; 603 if (SetEntriesInAcl(1, &change, old_dacl, &new_dacl) != ERROR_SUCCESS) { 604 LocalFree(security_descriptor); 605 return false; 606 } 607 608 DWORD rc = SetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()), 609 SE_FILE_OBJECT, DACL_SECURITY_INFORMATION, 610 NULL, NULL, new_dacl, NULL); 611 LocalFree(security_descriptor); 612 LocalFree(new_dacl); 613 614 return rc == ERROR_SUCCESS; 615#else 616 NOTIMPLEMENTED(); 617 return false; 618#endif 619} 620 621#endif // UNIT_TEST 622 623#if defined(OS_WIN) 624 // Loads the file passed in as an image section and touches pages to avoid 625 // subsequent hard page faults during LoadLibrary. The size to be pre read 626 // is passed in. If it is 0 then the whole file is paged in. The step size 627 // which indicates the number of bytes to skip after every page touched is 628 // also passed in. 629bool BASE_API PreReadImage(const wchar_t* file_path, size_t size_to_read, 630 size_t step_size); 631#endif // OS_WIN 632 633#if defined(OS_LINUX) 634// Broad categories of file systems as returned by statfs() on Linux. 635enum FileSystemType { 636 FILE_SYSTEM_UNKNOWN, // statfs failed. 637 FILE_SYSTEM_0, // statfs.f_type == 0 means unknown, may indicate AFS. 638 FILE_SYSTEM_ORDINARY, // on-disk filesystem like ext2 639 FILE_SYSTEM_NFS, 640 FILE_SYSTEM_SMB, 641 FILE_SYSTEM_CODA, 642 FILE_SYSTEM_MEMORY, // in-memory file system 643 FILE_SYSTEM_CGROUP, // cgroup control. 644 FILE_SYSTEM_OTHER, // any other value. 645 FILE_SYSTEM_TYPE_COUNT 646}; 647 648// Attempts determine the FileSystemType for |path|. 649// Returns false if |path| doesn't exist. 650bool GetFileSystemType(const FilePath& path, FileSystemType* type); 651#endif 652 653} // namespace file_util 654 655// Deprecated functions have been moved to this separate header file, 656// which must be included last after all the above definitions. 657#include "base/file_util_deprecated.h" 658 659#endif // BASE_FILE_UTIL_H_ 660