1#ifndef STRBUF_H 2#define STRBUF_H 3 4/** 5 * strbuf's are meant to be used with all the usual C string and memory 6 * APIs. Given that the length of the buffer is known, it's often better to 7 * use the mem* functions than a str* one (memchr vs. strchr e.g.). 8 * Though, one has to be careful about the fact that str* functions often 9 * stop on NULs and that strbufs may have embedded NULs. 10 * 11 * A strbuf is NUL terminated for convenience, but no function in the 12 * strbuf API actually relies on the string being free of NULs. 13 * 14 * strbufs have some invariants that are very important to keep in mind: 15 * 16 * - The `buf` member is never NULL, so it can be used in any usual C 17 * string operations safely. strbuf's _have_ to be initialized either by 18 * `strbuf_init()` or by `= STRBUF_INIT` before the invariants, though. 19 * 20 * Do *not* assume anything on what `buf` really is (e.g. if it is 21 * allocated memory or not), use `strbuf_detach()` to unwrap a memory 22 * buffer from its strbuf shell in a safe way. That is the sole supported 23 * way. This will give you a malloced buffer that you can later `free()`. 24 * 25 * However, it is totally safe to modify anything in the string pointed by 26 * the `buf` member, between the indices `0` and `len-1` (inclusive). 27 * 28 * - The `buf` member is a byte array that has at least `len + 1` bytes 29 * allocated. The extra byte is used to store a `'\0'`, allowing the 30 * `buf` member to be a valid C-string. Every strbuf function ensure this 31 * invariant is preserved. 32 * 33 * NOTE: It is OK to "play" with the buffer directly if you work it this 34 * way: 35 * 36 * strbuf_grow(sb, SOME_SIZE); <1> 37 * strbuf_setlen(sb, sb->len + SOME_OTHER_SIZE); 38 * 39 * <1> Here, the memory array starting at `sb->buf`, and of length 40 * `strbuf_avail(sb)` is all yours, and you can be sure that 41 * `strbuf_avail(sb)` is at least `SOME_SIZE`. 42 * 43 * NOTE: `SOME_OTHER_SIZE` must be smaller or equal to `strbuf_avail(sb)`. 44 * 45 * Doing so is safe, though if it has to be done in many places, adding the 46 * missing API to the strbuf module is the way to go. 47 * 48 * WARNING: Do _not_ assume that the area that is yours is of size `alloc 49 * - 1` even if it's true in the current implementation. Alloc is somehow a 50 * "private" member that should not be messed with. Use `strbuf_avail()` 51 * instead. 52*/ 53 54/** 55 * Data Structures 56 * --------------- 57 */ 58 59/** 60 * This is the string buffer structure. The `len` member can be used to 61 * determine the current length of the string, and `buf` member provides 62 * access to the string itself. 63 */ 64struct strbuf { 65size_t alloc; 66size_t len; 67char*buf; 68}; 69 70externchar strbuf_slopbuf[]; 71#define STRBUF_INIT { 0, 0, strbuf_slopbuf } 72 73/** 74 * Life Cycle Functions 75 * -------------------- 76 */ 77 78/** 79 * Initialize the structure. The second parameter can be zero or a bigger 80 * number to allocate memory, in case you want to prevent further reallocs. 81 */ 82externvoidstrbuf_init(struct strbuf *,size_t); 83 84/** 85 * Release a string buffer and the memory it used. After this call, the 86 * strbuf points to an empty string that does not need to be free()ed, as 87 * if it had been set to `STRBUF_INIT` and never modified. 88 * 89 * To clear a strbuf in preparation for further use without the overhead 90 * of free()ing and malloc()ing again, use strbuf_reset() instead. 91 */ 92externvoidstrbuf_release(struct strbuf *); 93 94/** 95 * Detach the string from the strbuf and returns it; you now own the 96 * storage the string occupies and it is your responsibility from then on 97 * to release it with `free(3)` when you are done with it. 98 * 99 * The strbuf that previously held the string is reset to `STRBUF_INIT` so 100 * it can be reused after calling this function. 101 */ 102externchar*strbuf_detach(struct strbuf *,size_t*); 103 104/** 105 * Attach a string to a buffer. You should specify the string to attach, 106 * the current length of the string and the amount of allocated memory. 107 * The amount must be larger than the string length, because the string you 108 * pass is supposed to be a NUL-terminated string. This string _must_ be 109 * malloc()ed, and after attaching, the pointer cannot be relied upon 110 * anymore, and neither be free()d directly. 111 */ 112externvoidstrbuf_attach(struct strbuf *,void*,size_t,size_t); 113 114/** 115 * Swap the contents of two string buffers. 116 */ 117staticinlinevoidstrbuf_swap(struct strbuf *a,struct strbuf *b) 118{ 119SWAP(*a, *b); 120} 121 122 123/** 124 * Functions related to the size of the buffer 125 * ------------------------------------------- 126 */ 127 128/** 129 * Determine the amount of allocated but unused memory. 130 */ 131staticinlinesize_tstrbuf_avail(const struct strbuf *sb) 132{ 133return sb->alloc ? sb->alloc - sb->len -1:0; 134} 135 136/** 137 * Ensure that at least this amount of unused memory is available after 138 * `len`. This is used when you know a typical size for what you will add 139 * and want to avoid repetitive automatic resizing of the underlying buffer. 140 * This is never a needed operation, but can be critical for performance in 141 * some cases. 142 */ 143externvoidstrbuf_grow(struct strbuf *,size_t); 144 145/** 146 * Set the length of the buffer to a given value. This function does *not* 147 * allocate new memory, so you should not perform a `strbuf_setlen()` to a 148 * length that is larger than `len + strbuf_avail()`. `strbuf_setlen()` is 149 * just meant as a 'please fix invariants from this strbuf I just messed 150 * with'. 151 */ 152staticinlinevoidstrbuf_setlen(struct strbuf *sb,size_t len) 153{ 154if(len > (sb->alloc ? sb->alloc -1:0)) 155die("BUG: strbuf_setlen() beyond buffer"); 156 sb->len = len; 157 sb->buf[len] ='\0'; 158} 159 160/** 161 * Empty the buffer by setting the size of it to zero. 162 */ 163#define strbuf_reset(sb) strbuf_setlen(sb, 0) 164 165 166/** 167 * Functions related to the contents of the buffer 168 * ----------------------------------------------- 169 */ 170 171/** 172 * Strip whitespace from the beginning (`ltrim`), end (`rtrim`), or both side 173 * (`trim`) of a string. 174 */ 175externvoidstrbuf_trim(struct strbuf *); 176externvoidstrbuf_rtrim(struct strbuf *); 177externvoidstrbuf_ltrim(struct strbuf *); 178 179/** 180 * Replace the contents of the strbuf with a reencoded form. Returns -1 181 * on error, 0 on success. 182 */ 183externintstrbuf_reencode(struct strbuf *sb,const char*from,const char*to); 184 185/** 186 * Lowercase each character in the buffer using `tolower`. 187 */ 188externvoidstrbuf_tolower(struct strbuf *sb); 189 190/** 191 * Compare two buffers. Returns an integer less than, equal to, or greater 192 * than zero if the first buffer is found, respectively, to be less than, 193 * to match, or be greater than the second buffer. 194 */ 195externintstrbuf_cmp(const struct strbuf *,const struct strbuf *); 196 197 198/** 199 * Adding data to the buffer 200 * ------------------------- 201 * 202 * NOTE: All of the functions in this section will grow the buffer as 203 * necessary. If they fail for some reason other than memory shortage and the 204 * buffer hadn't been allocated before (i.e. the `struct strbuf` was set to 205 * `STRBUF_INIT`), then they will free() it. 206 */ 207 208/** 209 * Add a single character to the buffer. 210 */ 211staticinlinevoidstrbuf_addch(struct strbuf *sb,int c) 212{ 213if(!strbuf_avail(sb)) 214strbuf_grow(sb,1); 215 sb->buf[sb->len++] = c; 216 sb->buf[sb->len] ='\0'; 217} 218 219/** 220 * Add a character the specified number of times to the buffer. 221 */ 222externvoidstrbuf_addchars(struct strbuf *sb,int c,size_t n); 223 224/** 225 * Insert data to the given position of the buffer. The remaining contents 226 * will be shifted, not overwritten. 227 */ 228externvoidstrbuf_insert(struct strbuf *,size_t pos,const void*,size_t); 229 230/** 231 * Remove given amount of data from a given position of the buffer. 232 */ 233externvoidstrbuf_remove(struct strbuf *,size_t pos,size_t len); 234 235/** 236 * Remove the bytes between `pos..pos+len` and replace it with the given 237 * data. 238 */ 239externvoidstrbuf_splice(struct strbuf *,size_t pos,size_t len, 240const void*,size_t); 241 242/** 243 * Add a NUL-terminated string to the buffer. Each line will be prepended 244 * by a comment character and a blank. 245 */ 246externvoidstrbuf_add_commented_lines(struct strbuf *out,const char*buf,size_t size); 247 248 249/** 250 * Add data of given length to the buffer. 251 */ 252externvoidstrbuf_add(struct strbuf *,const void*,size_t); 253 254/** 255 * Add a NUL-terminated string to the buffer. 256 * 257 * NOTE: This function will *always* be implemented as an inline or a macro 258 * using strlen, meaning that this is efficient to write things like: 259 * 260 * strbuf_addstr(sb, "immediate string"); 261 * 262 */ 263staticinlinevoidstrbuf_addstr(struct strbuf *sb,const char*s) 264{ 265strbuf_add(sb, s,strlen(s)); 266} 267 268/** 269 * Copy the contents of another buffer at the end of the current one. 270 */ 271externvoidstrbuf_addbuf(struct strbuf *sb,const struct strbuf *sb2); 272 273/** 274 * This function can be used to expand a format string containing 275 * placeholders. To that end, it parses the string and calls the specified 276 * function for every percent sign found. 277 * 278 * The callback function is given a pointer to the character after the `%` 279 * and a pointer to the struct strbuf. It is expected to add the expanded 280 * version of the placeholder to the strbuf, e.g. to add a newline 281 * character if the letter `n` appears after a `%`. The function returns 282 * the length of the placeholder recognized and `strbuf_expand()` skips 283 * over it. 284 * 285 * The format `%%` is automatically expanded to a single `%` as a quoting 286 * mechanism; callers do not need to handle the `%` placeholder themselves, 287 * and the callback function will not be invoked for this placeholder. 288 * 289 * All other characters (non-percent and not skipped ones) are copied 290 * verbatim to the strbuf. If the callback returned zero, meaning that the 291 * placeholder is unknown, then the percent sign is copied, too. 292 * 293 * In order to facilitate caching and to make it possible to give 294 * parameters to the callback, `strbuf_expand()` passes a context pointer, 295 * which can be used by the programmer of the callback as she sees fit. 296 */ 297typedefsize_t(*expand_fn_t) (struct strbuf *sb,const char*placeholder,void*context); 298externvoidstrbuf_expand(struct strbuf *sb,const char*format, expand_fn_t fn,void*context); 299 300/** 301 * Used as callback for `strbuf_expand()`, expects an array of 302 * struct strbuf_expand_dict_entry as context, i.e. pairs of 303 * placeholder and replacement string. The array needs to be 304 * terminated by an entry with placeholder set to NULL. 305 */ 306struct strbuf_expand_dict_entry { 307const char*placeholder; 308const char*value; 309}; 310externsize_tstrbuf_expand_dict_cb(struct strbuf *sb,const char*placeholder,void*context); 311 312/** 313 * Append the contents of one strbuf to another, quoting any 314 * percent signs ("%") into double-percents ("%%") in the 315 * destination. This is useful for literal data to be fed to either 316 * strbuf_expand or to the *printf family of functions. 317 */ 318externvoidstrbuf_addbuf_percentquote(struct strbuf *dst,const struct strbuf *src); 319 320/** 321 * Append the given byte size as a human-readable string (i.e. 12.23 KiB, 322 * 3.50 MiB). 323 */ 324externvoidstrbuf_humanise_bytes(struct strbuf *buf, off_t bytes); 325 326/** 327 * Add a formatted string to the buffer. 328 */ 329__attribute__((format(printf,2,3))) 330externvoidstrbuf_addf(struct strbuf *sb,const char*fmt, ...); 331 332/** 333 * Add a formatted string prepended by a comment character and a 334 * blank to the buffer. 335 */ 336__attribute__((format(printf,2,3))) 337externvoidstrbuf_commented_addf(struct strbuf *sb,const char*fmt, ...); 338 339__attribute__((format(printf,2,0))) 340externvoidstrbuf_vaddf(struct strbuf *sb,const char*fmt,va_list ap); 341 342/** 343 * Add the time specified by `tm`, as formatted by `strftime`. 344 * `tz_offset` is in decimal hhmm format, e.g. -600 means six hours west 345 * of Greenwich, and it's used to expand %z internally. However, tokens 346 * with modifiers (e.g. %Ez) are passed to `strftime`. 347 * `suppress_tz_name`, when set, expands %Z internally to the empty 348 * string rather than passing it to `strftime`. 349 */ 350externvoidstrbuf_addftime(struct strbuf *sb,const char*fmt, 351const struct tm *tm,int tz_offset, 352int suppress_tz_name); 353 354/** 355 * Read a given size of data from a FILE* pointer to the buffer. 356 * 357 * NOTE: The buffer is rewound if the read fails. If -1 is returned, 358 * `errno` must be consulted, like you would do for `read(3)`. 359 * `strbuf_read()`, `strbuf_read_file()` and `strbuf_getline_*()` 360 * family of functions have the same behaviour as well. 361 */ 362externsize_tstrbuf_fread(struct strbuf *,size_t,FILE*); 363 364/** 365 * Read the contents of a given file descriptor. The third argument can be 366 * used to give a hint about the file size, to avoid reallocs. If read fails, 367 * any partial read is undone. 368 */ 369extern ssize_t strbuf_read(struct strbuf *,int fd,size_t hint); 370 371/** 372 * Read the contents of a given file descriptor partially by using only one 373 * attempt of xread. The third argument can be used to give a hint about the 374 * file size, to avoid reallocs. Returns the number of new bytes appended to 375 * the sb. 376 */ 377extern ssize_t strbuf_read_once(struct strbuf *,int fd,size_t hint); 378 379/** 380 * Read the contents of a file, specified by its path. The third argument 381 * can be used to give a hint about the file size, to avoid reallocs. 382 * Return the number of bytes read or a negative value if some error 383 * occurred while opening or reading the file. 384 */ 385extern ssize_t strbuf_read_file(struct strbuf *sb,const char*path,size_t hint); 386 387/** 388 * Read the target of a symbolic link, specified by its path. The third 389 * argument can be used to give a hint about the size, to avoid reallocs. 390 */ 391externintstrbuf_readlink(struct strbuf *sb,const char*path,size_t hint); 392 393/** 394 * Write the whole content of the strbuf to the stream not stopping at 395 * NUL bytes. 396 */ 397extern ssize_t strbuf_write(struct strbuf *sb,FILE*stream); 398 399/** 400 * Read a line from a FILE *, overwriting the existing contents of 401 * the strbuf. The strbuf_getline*() family of functions share 402 * this signature, but have different line termination conventions. 403 * 404 * Reading stops after the terminator or at EOF. The terminator 405 * is removed from the buffer before returning. Returns 0 unless 406 * there was nothing left before EOF, in which case it returns `EOF`. 407 */ 408typedefint(*strbuf_getline_fn)(struct strbuf *,FILE*); 409 410/* Uses LF as the line terminator */ 411externintstrbuf_getline_lf(struct strbuf *sb,FILE*fp); 412 413/* Uses NUL as the line terminator */ 414externintstrbuf_getline_nul(struct strbuf *sb,FILE*fp); 415 416/* 417 * Similar to strbuf_getline_lf(), but additionally treats a CR that 418 * comes immediately before the LF as part of the terminator. 419 * This is the most friendly version to be used to read "text" files 420 * that can come from platforms whose native text format is CRLF 421 * terminated. 422 */ 423externintstrbuf_getline(struct strbuf *,FILE*); 424 425 426/** 427 * Like `strbuf_getline`, but keeps the trailing terminator (if 428 * any) in the buffer. 429 */ 430externintstrbuf_getwholeline(struct strbuf *,FILE*,int); 431 432/** 433 * Like `strbuf_getwholeline`, but operates on a file descriptor. 434 * It reads one character at a time, so it is very slow. Do not 435 * use it unless you need the correct position in the file 436 * descriptor. 437 */ 438externintstrbuf_getwholeline_fd(struct strbuf *,int,int); 439 440/** 441 * Set the buffer to the path of the current working directory. 442 */ 443externintstrbuf_getcwd(struct strbuf *sb); 444 445/** 446 * Add a path to a buffer, converting a relative path to an 447 * absolute one in the process. Symbolic links are not 448 * resolved. 449 */ 450externvoidstrbuf_add_absolute_path(struct strbuf *sb,const char*path); 451 452/** 453 * Canonize `path` (make it absolute, resolve symlinks, remove extra 454 * slashes) and append it to `sb`. Die with an informative error 455 * message if there is a problem. 456 * 457 * The directory part of `path` (i.e., everything up to the last 458 * dir_sep) must denote a valid, existing directory, but the last 459 * component need not exist. 460 * 461 * Callers that don't mind links should use the more lightweight 462 * strbuf_add_absolute_path() instead. 463 */ 464externvoidstrbuf_add_real_path(struct strbuf *sb,const char*path); 465 466 467/** 468 * Normalize in-place the path contained in the strbuf. See 469 * normalize_path_copy() for details. If an error occurs, the contents of "sb" 470 * are left untouched, and -1 is returned. 471 */ 472externintstrbuf_normalize_path(struct strbuf *sb); 473 474/** 475 * Strip whitespace from a buffer. The second parameter controls if 476 * comments are considered contents to be removed or not. 477 */ 478externvoidstrbuf_stripspace(struct strbuf *buf,int skip_comments); 479 480/** 481 * Temporary alias until all topic branches have switched to use 482 * strbuf_stripspace directly. 483 */ 484staticinlinevoidstripspace(struct strbuf *buf,int skip_comments) 485{ 486strbuf_stripspace(buf, skip_comments); 487} 488 489staticinlineintstrbuf_strip_suffix(struct strbuf *sb,const char*suffix) 490{ 491if(strip_suffix_mem(sb->buf, &sb->len, suffix)) { 492strbuf_setlen(sb, sb->len); 493return1; 494}else 495return0; 496} 497 498/** 499 * Split str (of length slen) at the specified terminator character. 500 * Return a null-terminated array of pointers to strbuf objects 501 * holding the substrings. The substrings include the terminator, 502 * except for the last substring, which might be unterminated if the 503 * original string did not end with a terminator. If max is positive, 504 * then split the string into at most max substrings (with the last 505 * substring containing everything following the (max-1)th terminator 506 * character). 507 * 508 * The most generic form is `strbuf_split_buf`, which takes an arbitrary 509 * pointer/len buffer. The `_str` variant takes a NUL-terminated string, 510 * the `_max` variant takes a strbuf, and just `strbuf_split` is a convenience 511 * wrapper to drop the `max` parameter. 512 * 513 * For lighter-weight alternatives, see string_list_split() and 514 * string_list_split_in_place(). 515 */ 516externstruct strbuf **strbuf_split_buf(const char*,size_t, 517int terminator,int max); 518 519staticinlinestruct strbuf **strbuf_split_str(const char*str, 520int terminator,int max) 521{ 522returnstrbuf_split_buf(str,strlen(str), terminator, max); 523} 524 525staticinlinestruct strbuf **strbuf_split_max(const struct strbuf *sb, 526int terminator,int max) 527{ 528returnstrbuf_split_buf(sb->buf, sb->len, terminator, max); 529} 530 531staticinlinestruct strbuf **strbuf_split(const struct strbuf *sb, 532int terminator) 533{ 534returnstrbuf_split_max(sb, terminator,0); 535} 536 537/** 538 * Free a NULL-terminated list of strbufs (for example, the return 539 * values of the strbuf_split*() functions). 540 */ 541externvoidstrbuf_list_free(struct strbuf **); 542 543/** 544 * Add the abbreviation, as generated by find_unique_abbrev, of `sha1` to 545 * the strbuf `sb`. 546 */ 547externvoidstrbuf_add_unique_abbrev(struct strbuf *sb, 548const unsigned char*sha1, 549int abbrev_len); 550 551/** 552 * Launch the user preferred editor to edit a file and fill the buffer 553 * with the file's contents upon the user completing their editing. The 554 * third argument can be used to set the environment which the editor is 555 * run in. If the buffer is NULL the editor is launched as usual but the 556 * file's contents are not read into the buffer upon completion. 557 */ 558externintlaunch_editor(const char*path,struct strbuf *buffer,const char*const*env); 559 560externvoidstrbuf_add_lines(struct strbuf *sb,const char*prefix,const char*buf,size_t size); 561 562/** 563 * Append s to sb, with the characters '<', '>', '&' and '"' converted 564 * into XML entities. 565 */ 566externvoidstrbuf_addstr_xml_quoted(struct strbuf *sb,const char*s); 567 568/** 569 * "Complete" the contents of `sb` by ensuring that either it ends with the 570 * character `term`, or it is empty. This can be used, for example, 571 * to ensure that text ends with a newline, but without creating an empty 572 * blank line if there is no content in the first place. 573 */ 574staticinlinevoidstrbuf_complete(struct strbuf *sb,char term) 575{ 576if(sb->len && sb->buf[sb->len -1] != term) 577strbuf_addch(sb, term); 578} 579 580staticinlinevoidstrbuf_complete_line(struct strbuf *sb) 581{ 582strbuf_complete(sb,'\n'); 583} 584 585/* 586 * Copy "name" to "sb", expanding any special @-marks as handled by 587 * interpret_branch_name(). The result is a non-qualified branch name 588 * (so "foo" or "origin/master" instead of "refs/heads/foo" or 589 * "refs/remotes/origin/master"). 590 * 591 * Note that the resulting name may not be a syntactically valid refname. 592 * 593 * If "allowed" is non-zero, restrict the set of allowed expansions. See 594 * interpret_branch_name() for details. 595 */ 596externvoidstrbuf_branchname(struct strbuf *sb,const char*name, 597unsigned allowed); 598 599/* 600 * Like strbuf_branchname() above, but confirm that the result is 601 * syntactically valid to be used as a local branch name in refs/heads/. 602 * 603 * The return value is "0" if the result is valid, and "-1" otherwise. 604 */ 605externintstrbuf_check_branch_ref(struct strbuf *sb,const char*name); 606 607externvoidstrbuf_addstr_urlencode(struct strbuf *,const char*, 608int reserved); 609 610__attribute__((format(printf,1,2))) 611externintprintf_ln(const char*fmt, ...); 612__attribute__((format(printf,2,3))) 613externintfprintf_ln(FILE*fp,const char*fmt, ...); 614 615char*xstrdup_tolower(const char*); 616 617/** 618 * Create a newly allocated string using printf format. You can do this easily 619 * with a strbuf, but this provides a shortcut to save a few lines. 620 */ 621__attribute__((format(printf,1,0))) 622char*xstrvfmt(const char*fmt,va_list ap); 623__attribute__((format(printf,1,2))) 624char*xstrfmt(const char*fmt, ...); 625 626#endif/* STRBUF_H */