src/fileops.h

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7 #ifndef INCLUDE_fileops_h__
   8 #define INCLUDE_fileops_h__
   9
  10 #include "common.h"
  11 #include "map.h"
  12 #include "posix.h"
  13 #include "path.h"
  14
  15 /**
  16  * Filebuffer methods
  17  *
  18  * Read whole files into an in-memory buffer for processing
  19  */
  20 extern int git_futils_readbuffer(git_buf *obj, const char *path);
  21 extern int git_futils_readbuffer_updated(
  22         git_buf *obj, const char *path, time_t *mtime, size_t *size, int *updated);
  23 extern int git_futils_readbuffer_fd(git_buf *obj, git_file fd, size_t len);
  24
  25 extern int git_futils_writebuffer(
  26         const git_buf *buf, const char *path, int open_flags, mode_t mode);
  27
  28 /**
  29  * File utils
  30  *
  31  * These are custom filesystem-related helper methods. They are
  32  * rather high level, and wrap the underlying POSIX methods
  33  *
  34  * All these methods return 0 on success,
  35  * or an error code on failure and an error message is set.
  36  */
  37
  38 /**
  39  * Create and open a file, while also
  40  * creating all the folders in its path
  41  */
  42 extern int git_futils_creat_withpath(const char *path, const mode_t dirmode, const mode_t mode);
  43
  44 /**
  45  * Create an open a process-locked file
  46  */
  47 extern int git_futils_creat_locked(const char *path, const mode_t mode);
  48
  49 /**
  50  * Create an open a process-locked file, while
  51  * also creating all the folders in its path
  52  */
  53 extern int git_futils_creat_locked_withpath(const char *path, const mode_t dirmode, const mode_t mode);
  54
  55 /**
  56  * Create a path recursively
  57  *
  58  * If a base parameter is being passed, it's expected to be valued with a
  59  * path pointing to an already existing directory.
  60  */
  61 extern int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode);
  62
  63 /**
  64  * Flags to pass to `git_futils_mkdir`.
  65  *
  66  * * GIT_MKDIR_EXCL is "exclusive" - i.e. generate an error if dir exists.
  67  * * GIT_MKDIR_PATH says to make all components in the path.
  68  * * GIT_MKDIR_CHMOD says to chmod the final directory entry after creation
  69  * * GIT_MKDIR_CHMOD_PATH says to chmod each directory component in the path
  70  * * GIT_MKDIR_SKIP_LAST says to leave off the last element of the path
  71  * * GIT_MKDIR_SKIP_LAST2 says to leave off the last 2 elements of the path
  72  * * GIT_MKDIR_VERIFY_DIR says confirm final item is a dir, not just EEXIST
  73  *
  74  * Note that the chmod options will be executed even if the directory already
  75  * exists, unless GIT_MKDIR_EXCL is given.
  76  */
  77 typedef enum {
  78         GIT_MKDIR_EXCL = 1,
  79         GIT_MKDIR_PATH = 2,
  80         GIT_MKDIR_CHMOD = 4,
  81         GIT_MKDIR_CHMOD_PATH = 8,
  82         GIT_MKDIR_SKIP_LAST = 16,
  83         GIT_MKDIR_SKIP_LAST2 = 32,
  84         GIT_MKDIR_VERIFY_DIR = 64,
  85 } git_futils_mkdir_flags;
  86
  87 /**
  88  * Create a directory or entire path.
  89  *
  90  * This makes a directory (and the entire path leading up to it if requested),
  91  * and optionally chmods the directory immediately after (or each part of the
  92  * path if requested).
  93  *
  94  * @param path The path to create.
  95  * @param base Root for relative path.  These directories will never be made.
  96  * @param mode The mode to use for created directories.
  97  * @param flags Combination of the mkdir flags above.
  98  * @return 0 on success, else error code
  99  */
 100 extern int git_futils_mkdir(const char *path, const char *base, mode_t mode, uint32_t flags);
 101
 102 /**
 103  * Create all the folders required to contain
 104  * the full path of a file
 105  */
 106 extern int git_futils_mkpath2file(const char *path, const mode_t mode);
 107
 108 /**
 109  * Flags to pass to `git_futils_rmdir_r`.
 110  *
 111  * * GIT_RMDIR_EMPTY_HIERARCHY - the default; remove hierarchy of empty
 112  *       dirs and generate error if any files are found.
 113  * * GIT_RMDIR_REMOVE_FILES    - attempt to remove files in the hierarchy.
 114  * * GIT_RMDIR_SKIP_NONEMPTY   - skip non-empty directories with no error.
 115  * * GIT_RMDIR_EMPTY_PARENTS   - remove containing directories up to base
 116  *       if removing this item leaves them empty
 117  * * GIT_RMDIR_REMOVE_BLOCKERS - remove blocking file that causes ENOTDIR
 118  *
 119  * The old values translate into the new as follows:
 120  *
 121  * * GIT_DIRREMOVAL_EMPTY_HIERARCHY == GIT_RMDIR_EMPTY_HIERARCHY
 122  * * GIT_DIRREMOVAL_FILES_AND_DIRS  ~= GIT_RMDIR_REMOVE_FILES
 123  * * GIT_DIRREMOVAL_ONLY_EMPTY_DIRS == GIT_RMDIR_SKIP_NONEMPTY
 124  */
 125 typedef enum {
 126         GIT_RMDIR_EMPTY_HIERARCHY = 0,
 127         GIT_RMDIR_REMOVE_FILES    = (1 << 0),
 128         GIT_RMDIR_SKIP_NONEMPTY   = (1 << 1),
 129         GIT_RMDIR_EMPTY_PARENTS   = (1 << 2),
 130         GIT_RMDIR_REMOVE_BLOCKERS = (1 << 3),
 131 } git_futils_rmdir_flags;
 132
 133 /**
 134  * Remove path and any files and directories beneath it.
 135  *
 136  * @param path Path to the top level directory to process.
 137  * @param base Root for relative path.
 138  * @param flags Combination of git_futils_rmdir_flags values
 139  * @return 0 on success; -1 on error.
 140  */
 141 extern int git_futils_rmdir_r(const char *path, const char *base, uint32_t flags);
 142
 143 /**
 144  * Remove all files and directories beneath the specified path.
 145  *
 146  * @param path Path to the top level directory to process.
 147  * @return 0 on success; -1 on error.
 148  */
 149 extern int git_futils_cleanupdir_r(const char *path);
 150
 151 /**
 152  * Create and open a temporary file with a `_git2_` suffix.
 153  * Writes the filename into path_out.
 154  * @return On success, an open file descriptor, else an error code < 0.
 155  */
 156 extern int git_futils_mktmp(git_buf *path_out, const char *filename);
 157
 158 /**
 159  * Move a file on the filesystem, create the
 160  * destination path if it doesn't exist
 161  */
 162 extern int git_futils_mv_withpath(const char *from, const char *to, const mode_t dirmode);
 163
 164 /**
 165  * Copy a file
 166  *
 167  * The filemode will be used for the newly created file.
 168  */
 169 extern int git_futils_cp(
 170         const char *from,
 171         const char *to,
 172         mode_t filemode);
 173
 174 /**
 175  * Flags that can be passed to `git_futils_cp_r`.
 176  *
 177  * - GIT_CPDIR_CREATE_EMPTY_DIRS: create directories even if there are no
 178  *   files under them (otherwise directories will only be created lazily
 179  *   when a file inside them is copied).
 180  * - GIT_CPDIR_COPY_SYMLINKS: copy symlinks, otherwise they are ignored.
 181  * - GIT_CPDIR_COPY_DOTFILES: copy files with leading '.', otherwise ignored.
 182  * - GIT_CPDIR_OVERWRITE: overwrite pre-existing files with source content,
 183  *   otherwise they are silently skipped.
 184  * - GIT_CPDIR_CHMOD_DIRS: explicitly chmod directories to `dirmode`
 185  * - GIT_CPDIR_SIMPLE_TO_MODE: default tries to replicate the mode of the
 186  *   source file to the target; with this flag, always use 0666 (or 0777 if
 187  *   source has exec bits set) for target.
 188  */
 189 typedef enum {
 190         GIT_CPDIR_CREATE_EMPTY_DIRS = (1u << 0),
 191         GIT_CPDIR_COPY_SYMLINKS     = (1u << 1),
 192         GIT_CPDIR_COPY_DOTFILES     = (1u << 2),
 193         GIT_CPDIR_OVERWRITE         = (1u << 3),
 194         GIT_CPDIR_CHMOD_DIRS        = (1u << 4),
 195         GIT_CPDIR_SIMPLE_TO_MODE    = (1u << 5),
 196 } git_futils_cpdir_flags;
 197
 198 /**
 199  * Copy a directory tree.
 200  *
 201  * This copies directories and files from one root to another.  You can
 202  * pass a combinationof GIT_CPDIR flags as defined above.
 203  *
 204  * If you pass the CHMOD flag, then the dirmode will be applied to all
 205  * directories that are created during the copy, overiding the natural
 206  * permissions.  If you do not pass the CHMOD flag, then the dirmode
 207  * will actually be copied from the source files and the `dirmode` arg
 208  * will be ignored.
 209  */
 210 extern int git_futils_cp_r(
 211         const char *from,
 212         const char *to,
 213         uint32_t flags,
 214         mode_t dirmode);
 215
 216 /**
 217  * Open a file readonly and set error if needed.
 218  */
 219 extern int git_futils_open_ro(const char *path);
 220
 221 /**
 222  * Get the filesize in bytes of a file
 223  */
 224 extern git_off_t git_futils_filesize(git_file fd);
 225
 226 #define GIT_PERMS_EXECUTABLE(MODE)  (((MODE) & 0111) != 0)
 227 #define GIT_PERMS_CANONICAL(MODE)       (GIT_PERMS_EXECUTABLE(MODE) ? 0755 : 0644)
 228 #define GIT_PERMS_FOR_WRITE(MODE)   (GIT_PERMS_EXECUTABLE(MODE) ? 0777 : 0666)
 229
 230 #define GIT_MODE_PERMS_MASK                     0777
 231 #define GIT_MODE_TYPE_MASK                      0170000
 232 #define GIT_MODE_TYPE(MODE)                     ((MODE) & GIT_MODE_TYPE_MASK)
 233 #define GIT_MODE_ISBLOB(MODE)           (GIT_MODE_TYPE(MODE) == GIT_MODE_TYPE(GIT_FILEMODE_BLOB))
 234
 235 /**
 236  * Convert a mode_t from the OS to a legal git mode_t value.
 237  */
 238 extern mode_t git_futils_canonical_mode(mode_t raw_mode);
 239
 240
 241 /**
 242  * Read-only map all or part of a file into memory.
 243  * When possible this function should favor a virtual memory
 244  * style mapping over some form of malloc()+read(), as the
 245  * data access will be random and is not likely to touch the
 246  * majority of the region requested.
 247  *
 248  * @param out buffer to populate with the mapping information.
 249  * @param fd open descriptor to configure the mapping from.
 250  * @param begin first byte to map, this should be page aligned.
 251  * @param len number of bytes to map.
 252  * @return
 253  * - 0 on success;
 254  * - -1 on error.
 255  */
 256 extern int git_futils_mmap_ro(
 257         git_map *out,
 258         git_file fd,
 259         git_off_t begin,
 260         size_t len);
 261
 262 /**
 263  * Read-only map an entire file.
 264  *
 265  * @param out buffer to populate with the mapping information.
 266  * @param path path to file to be opened.
 267  * @return
 268  * - 0 on success;
 269  * - GIT_ENOTFOUND if not found;
 270  * - -1 on an unspecified OS related error.
 271  */
 272 extern int git_futils_mmap_ro_file(
 273         git_map *out,
 274         const char *path);
 275
 276 /**
 277  * Release the memory associated with a previous memory mapping.
 278  * @param map the mapping description previously configured.
 279  */
 280 extern void git_futils_mmap_free(git_map *map);
 281
 282 /**
 283  * Find a "global" file (i.e. one in a user's home directory).
 284  *
 285  * @param path buffer to write the full path into
 286  * @param filename name of file to find in the home directory
 287  * @return 0 if found, GIT_ENOTFOUND if not found, or -1 on other OS error
 288  */
 289 extern int git_futils_find_global_file(git_buf *path, const char *filename);
 290
 291 /**
 292  * Find an "XDG" file (i.e. one in user's XDG config path).
 293  *
 294  * @param path buffer to write the full path into
 295  * @param filename name of file to find in the home directory
 296  * @return 0 if found, GIT_ENOTFOUND if not found, or -1 on other OS error
 297  */
 298 extern int git_futils_find_xdg_file(git_buf *path, const char *filename);
 299
 300 /**
 301  * Find a "system" file (i.e. one shared for all users of the system).
 302  *
 303  * @param path buffer to write the full path into
 304  * @param filename name of file to find in the home directory
 305  * @return 0 if found, GIT_ENOTFOUND if not found, or -1 on other OS error
 306  */
 307 extern int git_futils_find_system_file(git_buf *path, const char *filename);
 308
 309 typedef enum {
 310         GIT_FUTILS_DIR_SYSTEM = 0,
 311         GIT_FUTILS_DIR_GLOBAL = 1,
 312         GIT_FUTILS_DIR_XDG    = 2,
 313         GIT_FUTILS_DIR__MAX   = 3,
 314 } git_futils_dir_t;
 315
 316 /**
 317  * Configures global data for configuration file search paths.
 318  *
 319  * @return 0 on success, <0 on failure
 320  */
 321 extern int git_futils_dirs_global_init(void);
 322
 323 /**
 324  * Get the search path for global/system/xdg files
 325  *
 326  * @param out pointer to git_buf containing search path
 327  * @param which which list of paths to return
 328  * @return 0 on success, <0 on failure
 329  */
 330 extern int git_futils_dirs_get(const git_buf **out, git_futils_dir_t which);
 331
 332 /**
 333  * Get search path into a preallocated buffer
 334  *
 335  * @param out String buffer to write into
 336  * @param outlen Size of string buffer
 337  * @param which Which search path to return
 338  * @return 0 on success, GIT_EBUFS if out is too small, <0 on other failure
 339  */
 340
 341 extern int git_futils_dirs_get_str(
 342         char *out, size_t outlen, git_futils_dir_t which);
 343
 344 /**
 345  * Set search paths for global/system/xdg files
 346  *
 347  * The first occurrence of the magic string "$PATH" in the new value will
 348  * be replaced with the old value of the search path.
 349  *
 350  * @param which Which search path to modify
 351  * @param paths New search path (separated by GIT_PATH_LIST_SEPARATOR)
 352  * @return 0 on success, <0 on failure (allocation error)
 353  */
 354 extern int git_futils_dirs_set(git_futils_dir_t which, const char *paths);
 355
 356 /**
 357  * Release / reset all search paths
 358  */
 359 extern void git_futils_dirs_free(void);
 360
 361 /**
 362  * Create a "fake" symlink (text file containing the target path).
 363  *
 364  * @param new symlink file to be created
 365  * @param old original symlink target
 366  * @return 0 on success, -1 on error
 367  */
 368 extern int git_futils_fake_symlink(const char *new, const char *old);
 369
 370 /**
 371  * A file stamp represents a snapshot of information about a file that can
 372  * be used to test if the file changes.  This portable implementation is
 373  * based on stat data about that file, but it is possible that OS specific
 374  * versions could be implemented in the future.
 375  */
 376 typedef struct {
 377         git_time_t mtime;
 378         git_off_t  size;
 379         unsigned int ino;
 380 } git_futils_filestamp;
 381
 382 /**
 383  * Compare stat information for file with reference info.
 384  *
 385  * This function updates the file stamp to current data for the given path
 386  * and returns 0 if the file is up-to-date relative to the prior setting or
 387  * 1 if the file has been changed.  (This also may return GIT_ENOTFOUND if
 388  * the file doesn't exist.)
 389  *
 390  * @param stamp File stamp to be checked
 391  * @param path Path to stat and check if changed
 392  * @return 0 if up-to-date, 1 if out-of-date, <0 on error
 393  */
 394 extern int git_futils_filestamp_check(
 395         git_futils_filestamp *stamp, const char *path);
 396
 397 /**
 398  * Set or reset file stamp data
 399  *
 400  * This writes the target file stamp.  If the source is NULL, this will set
 401  * the target stamp to values that will definitely be out of date.  If the
 402  * source is not NULL, this copies the source values to the target.
 403  *
 404  * @param tgt File stamp to write to
 405  * @param src File stamp to copy from or NULL to clear the target
 406  */
 407 extern void git_futils_filestamp_set(
 408         git_futils_filestamp *tgt, const git_futils_filestamp *src);
 409
 410 #endif /* INCLUDE_fileops_h__ */