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Diffstat (limited to 'brillo/file_utils.h')
| -rw-r--r-- | brillo/file_utils.h | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/brillo/file_utils.h b/brillo/file_utils.h index 3862a43..f328165 100644 --- a/brillo/file_utils.h +++ b/brillo/file_utils.h @@ -144,6 +144,48 @@ BRILLO_EXPORT bool WriteBlobToFileAtomic(const base::FilePath& path, blob.size(), mode); } +// ComputeDirectoryDiskUsage() is similar to base::ComputeDirectorySize() in +// libbase, but it returns the actual disk usage instead of the apparent size. +// In another word, ComputeDirectoryDiskUsage() behaves like "du -s +// --apparent-size", and ComputeDirectorySize() behaves like "du -s". The +// primary difference is that sparse file and files on filesystem with +// transparent compression will report smaller file size than +// ComputeDirectorySize(). Returns the total used bytes. +// The following behaviours of this function is guaranteed and is verified by +// unit tests: +// - This function recursively processes directory down the tree, so disk space +// used by files in all the subdirectories are counted. +// - Symbolic links will not be followed (the size of link itself is counted, +// the target is not) +// - Hidden files are counted as well. +// The following behaviours are not guaranteed, and it is recommended to avoid +// them in the field. Their current behaviour is provided for reference only: +// - This function doesn't care about filesystem boundaries, so it'll cross +// filesystem boundary to count file size if there's one in the specified +// directory. +// - Hard links will be treated like normal files, so they could be +// over-reported. +// - Directories that the current user doesn't have permission to list/stat will +// be ignored, and an error will be logged but the returned result could be +// under-reported without error in the returned value. +// - Deduplication (should the filesystem support it) is ignored, and the result +// could be over-reported. +// - Doesn't check if |root_path| exists, a non-existent directory will results +// in 0 bytes without any error. +// - There are no limit on the depth of file system tree, the program will crash +// if it run out of memory to hold the entire depth of file system tree. +// - If the directory is modified during this function call, there's no +// guarantee on if the function will count the updated or original file system +// state. The function could choose to count the updated state for one file and +// original state for another file. +// - Non-POSIX system is not supported. +// - Disk space used by directory (and its subdirectories) itself is counted. +// +// Parameters +// root_path - The directory to compute the size for +BRILLO_EXPORT int64_t +ComputeDirectoryDiskUsage(const base::FilePath& root_path); + } // namespace brillo #endif // LIBBRILLO_BRILLO_FILE_UTILS_H_ |