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. You should not use the 86 * string buffer after using this function, unless you initialize it again. 87 */ 88externvoidstrbuf_release(struct strbuf *); 89 90/** 91 * Detach the string from the strbuf and returns it; you now own the 92 * storage the string occupies and it is your responsibility from then on 93 * to release it with `free(3)` when you are done with it. 94 */ 95externchar*strbuf_detach(struct strbuf *,size_t*); 96 97/** 98 * Attach a string to a buffer. You should specify the string to attach, 99 * the current length of the string and the amount of allocated memory. 100 * The amount must be larger than the string length, because the string you 101 * pass is supposed to be a NUL-terminated string. This string _must_ be 102 * malloc()ed, and after attaching, the pointer cannot be relied upon 103 * anymore, and neither be free()d directly. 104 */ 105externvoidstrbuf_attach(struct strbuf *,void*,size_t,size_t); 106 107/** 108 * Swap the contents of two string buffers. 109 */ 110staticinlinevoidstrbuf_swap(struct strbuf *a,struct strbuf *b) 111{ 112struct strbuf tmp = *a; 113*a = *b; 114*b = tmp; 115} 116 117 118/** 119 * Functions related to the size of the buffer 120 * ------------------------------------------- 121 */ 122 123/** 124 * Determine the amount of allocated but unused memory. 125 */ 126staticinlinesize_tstrbuf_avail(const struct strbuf *sb) 127{ 128return sb->alloc ? sb->alloc - sb->len -1:0; 129} 130 131/** 132 * Ensure that at least this amount of unused memory is available after 133 * `len`. This is used when you know a typical size for what you will add 134 * and want to avoid repetitive automatic resizing of the underlying buffer. 135 * This is never a needed operation, but can be critical for performance in 136 * some cases. 137 */ 138externvoidstrbuf_grow(struct strbuf *,size_t); 139 140/** 141 * Set the length of the buffer to a given value. This function does *not* 142 * allocate new memory, so you should not perform a `strbuf_setlen()` to a 143 * length that is larger than `len + strbuf_avail()`. `strbuf_setlen()` is 144 * just meant as a 'please fix invariants from this strbuf I just messed 145 * with'. 146 */ 147staticinlinevoidstrbuf_setlen(struct strbuf *sb,size_t len) 148{ 149if(len > (sb->alloc ? sb->alloc -1:0)) 150die("BUG: strbuf_setlen() beyond buffer"); 151 sb->len = len; 152 sb->buf[len] ='\0'; 153} 154 155/** 156 * Empty the buffer by setting the size of it to zero. 157 */ 158#define strbuf_reset(sb) strbuf_setlen(sb, 0) 159 160 161/** 162 * Functions related to the contents of the buffer 163 * ----------------------------------------------- 164 */ 165 166/** 167 * Strip whitespace from the beginning (`ltrim`), end (`rtrim`), or both side 168 * (`trim`) of a string. 169 */ 170externvoidstrbuf_trim(struct strbuf *); 171externvoidstrbuf_rtrim(struct strbuf *); 172externvoidstrbuf_ltrim(struct strbuf *); 173 174/** 175 * Replace the contents of the strbuf with a reencoded form. Returns -1 176 * on error, 0 on success. 177 */ 178externintstrbuf_reencode(struct strbuf *sb,const char*from,const char*to); 179 180/** 181 * Lowercase each character in the buffer using `tolower`. 182 */ 183externvoidstrbuf_tolower(struct strbuf *sb); 184 185/** 186 * Compare two buffers. Returns an integer less than, equal to, or greater 187 * than zero if the first buffer is found, respectively, to be less than, 188 * to match, or be greater than the second buffer. 189 */ 190externintstrbuf_cmp(const struct strbuf *,const struct strbuf *); 191 192 193/** 194 * Adding data to the buffer 195 * ------------------------- 196 * 197 * NOTE: All of the functions in this section will grow the buffer as 198 * necessary. If they fail for some reason other than memory shortage and the 199 * buffer hadn't been allocated before (i.e. the `struct strbuf` was set to 200 * `STRBUF_INIT`), then they will free() it. 201 */ 202 203/** 204 * Add a single character to the buffer. 205 */ 206staticinlinevoidstrbuf_addch(struct strbuf *sb,int c) 207{ 208if(!strbuf_avail(sb)) 209strbuf_grow(sb,1); 210 sb->buf[sb->len++] = c; 211 sb->buf[sb->len] ='\0'; 212} 213 214/** 215 * Add a character the specified number of times to the buffer. 216 */ 217externvoidstrbuf_addchars(struct strbuf *sb,int c,size_t n); 218 219/** 220 * Insert data to the given position of the buffer. The remaining contents 221 * will be shifted, not overwritten. 222 */ 223externvoidstrbuf_insert(struct strbuf *,size_t pos,const void*,size_t); 224 225/** 226 * Remove given amount of data from a given position of the buffer. 227 */ 228externvoidstrbuf_remove(struct strbuf *,size_t pos,size_t len); 229 230/** 231 * Remove the bytes between `pos..pos+len` and replace it with the given 232 * data. 233 */ 234externvoidstrbuf_splice(struct strbuf *,size_t pos,size_t len, 235const void*,size_t); 236 237/** 238 * Add a NUL-terminated string to the buffer. Each line will be prepended 239 * by a comment character and a blank. 240 */ 241externvoidstrbuf_add_commented_lines(struct strbuf *out,const char*buf,size_t size); 242 243 244/** 245 * Add data of given length to the buffer. 246 */ 247externvoidstrbuf_add(struct strbuf *,const void*,size_t); 248 249/** 250 * Add a NUL-terminated string to the buffer. 251 * 252 * NOTE: This function will *always* be implemented as an inline or a macro 253 * using strlen, meaning that this is efficient to write things like: 254 * 255 * strbuf_addstr(sb, "immediate string"); 256 * 257 */ 258staticinlinevoidstrbuf_addstr(struct strbuf *sb,const char*s) 259{ 260strbuf_add(sb, s,strlen(s)); 261} 262 263/** 264 * Copy the contents of another buffer at the end of the current one. 265 */ 266staticinlinevoidstrbuf_addbuf(struct strbuf *sb,const struct strbuf *sb2) 267{ 268strbuf_grow(sb, sb2->len); 269strbuf_add(sb, sb2->buf, sb2->len); 270} 271 272/** 273 * Copy part of the buffer from a given position till a given length to the 274 * end of the buffer. 275 */ 276externvoidstrbuf_adddup(struct strbuf *sb,size_t pos,size_t len); 277 278/** 279 * This function can be used to expand a format string containing 280 * placeholders. To that end, it parses the string and calls the specified 281 * function for every percent sign found. 282 * 283 * The callback function is given a pointer to the character after the `%` 284 * and a pointer to the struct strbuf. It is expected to add the expanded 285 * version of the placeholder to the strbuf, e.g. to add a newline 286 * character if the letter `n` appears after a `%`. The function returns 287 * the length of the placeholder recognized and `strbuf_expand()` skips 288 * over it. 289 * 290 * The format `%%` is automatically expanded to a single `%` as a quoting 291 * mechanism; callers do not need to handle the `%` placeholder themselves, 292 * and the callback function will not be invoked for this placeholder. 293 * 294 * All other characters (non-percent and not skipped ones) are copied 295 * verbatim to the strbuf. If the callback returned zero, meaning that the 296 * placeholder is unknown, then the percent sign is copied, too. 297 * 298 * In order to facilitate caching and to make it possible to give 299 * parameters to the callback, `strbuf_expand()` passes a context pointer, 300 * which can be used by the programmer of the callback as she sees fit. 301 */ 302typedefsize_t(*expand_fn_t) (struct strbuf *sb,const char*placeholder,void*context); 303externvoidstrbuf_expand(struct strbuf *sb,const char*format, expand_fn_t fn,void*context); 304 305/** 306 * Used as callback for `strbuf_expand()`, expects an array of 307 * struct strbuf_expand_dict_entry as context, i.e. pairs of 308 * placeholder and replacement string. The array needs to be 309 * terminated by an entry with placeholder set to NULL. 310 */ 311struct strbuf_expand_dict_entry { 312const char*placeholder; 313const char*value; 314}; 315externsize_tstrbuf_expand_dict_cb(struct strbuf *sb,const char*placeholder,void*context); 316 317/** 318 * Append the contents of one strbuf to another, quoting any 319 * percent signs ("%") into double-percents ("%%") in the 320 * destination. This is useful for literal data to be fed to either 321 * strbuf_expand or to the *printf family of functions. 322 */ 323externvoidstrbuf_addbuf_percentquote(struct strbuf *dst,const struct strbuf *src); 324 325/** 326 * Append the given byte size as a human-readable string (i.e. 12.23 KiB, 327 * 3.50 MiB). 328 */ 329externvoidstrbuf_humanise_bytes(struct strbuf *buf, off_t bytes); 330 331/** 332 * Add a formatted string to the buffer. 333 */ 334__attribute__((format(printf,2,3))) 335externvoidstrbuf_addf(struct strbuf *sb,const char*fmt, ...); 336 337/** 338 * Add a formatted string prepended by a comment character and a 339 * blank to the buffer. 340 */ 341__attribute__((format(printf,2,3))) 342externvoidstrbuf_commented_addf(struct strbuf *sb,const char*fmt, ...); 343 344__attribute__((format(printf,2,0))) 345externvoidstrbuf_vaddf(struct strbuf *sb,const char*fmt,va_list ap); 346 347/** 348 * Read a given size of data from a FILE* pointer to the buffer. 349 * 350 * NOTE: The buffer is rewound if the read fails. If -1 is returned, 351 * `errno` must be consulted, like you would do for `read(3)`. 352 * `strbuf_read()`, `strbuf_read_file()` and `strbuf_getline()` has the 353 * same behaviour as well. 354 */ 355externsize_tstrbuf_fread(struct strbuf *,size_t,FILE*); 356 357/** 358 * Read the contents of a given file descriptor. The third argument can be 359 * used to give a hint about the file size, to avoid reallocs. If read fails, 360 * any partial read is undone. 361 */ 362extern ssize_t strbuf_read(struct strbuf *,int fd,size_t hint); 363 364/** 365 * Read the contents of a file, specified by its path. The third argument 366 * can be used to give a hint about the file size, to avoid reallocs. 367 */ 368extern ssize_t strbuf_read_file(struct strbuf *sb,const char*path,size_t hint); 369 370/** 371 * Read the target of a symbolic link, specified by its path. The third 372 * argument can be used to give a hint about the size, to avoid reallocs. 373 */ 374externintstrbuf_readlink(struct strbuf *sb,const char*path,size_t hint); 375 376/** 377 * Read a line from a FILE *, overwriting the existing contents 378 * of the strbuf. The second argument specifies the line 379 * terminator character, typically `'\n'`. 380 * Reading stops after the terminator or at EOF. The terminator 381 * is removed from the buffer before returning. Returns 0 unless 382 * there was nothing left before EOF, in which case it returns `EOF`. 383 */ 384externintstrbuf_getline(struct strbuf *,FILE*,int); 385 386/** 387 * Like `strbuf_getline`, but keeps the trailing terminator (if 388 * any) in the buffer. 389 */ 390externintstrbuf_getwholeline(struct strbuf *,FILE*,int); 391 392/** 393 * Like `strbuf_getwholeline`, but operates on a file descriptor. 394 * It reads one character at a time, so it is very slow. Do not 395 * use it unless you need the correct position in the file 396 * descriptor. 397 */ 398externintstrbuf_getwholeline_fd(struct strbuf *,int,int); 399 400/** 401 * Set the buffer to the path of the current working directory. 402 */ 403externintstrbuf_getcwd(struct strbuf *sb); 404 405/** 406 * Add a path to a buffer, converting a relative path to an 407 * absolute one in the process. Symbolic links are not 408 * resolved. 409 */ 410externvoidstrbuf_add_absolute_path(struct strbuf *sb,const char*path); 411 412/** 413 * Strip whitespace from a buffer. The second parameter controls if 414 * comments are considered contents to be removed or not. 415 */ 416externvoidstripspace(struct strbuf *buf,int skip_comments); 417 418staticinlineintstrbuf_strip_suffix(struct strbuf *sb,const char*suffix) 419{ 420if(strip_suffix_mem(sb->buf, &sb->len, suffix)) { 421strbuf_setlen(sb, sb->len); 422return1; 423}else 424return0; 425} 426 427/** 428 * Split str (of length slen) at the specified terminator character. 429 * Return a null-terminated array of pointers to strbuf objects 430 * holding the substrings. The substrings include the terminator, 431 * except for the last substring, which might be unterminated if the 432 * original string did not end with a terminator. If max is positive, 433 * then split the string into at most max substrings (with the last 434 * substring containing everything following the (max-1)th terminator 435 * character). 436 * 437 * The most generic form is `strbuf_split_buf`, which takes an arbitrary 438 * pointer/len buffer. The `_str` variant takes a NUL-terminated string, 439 * the `_max` variant takes a strbuf, and just `strbuf_split` is a convenience 440 * wrapper to drop the `max` parameter. 441 * 442 * For lighter-weight alternatives, see string_list_split() and 443 * string_list_split_in_place(). 444 */ 445externstruct strbuf **strbuf_split_buf(const char*,size_t, 446int terminator,int max); 447 448staticinlinestruct strbuf **strbuf_split_str(const char*str, 449int terminator,int max) 450{ 451returnstrbuf_split_buf(str,strlen(str), terminator, max); 452} 453 454staticinlinestruct strbuf **strbuf_split_max(const struct strbuf *sb, 455int terminator,int max) 456{ 457returnstrbuf_split_buf(sb->buf, sb->len, terminator, max); 458} 459 460staticinlinestruct strbuf **strbuf_split(const struct strbuf *sb, 461int terminator) 462{ 463returnstrbuf_split_max(sb, terminator,0); 464} 465 466/** 467 * Free a NULL-terminated list of strbufs (for example, the return 468 * values of the strbuf_split*() functions). 469 */ 470externvoidstrbuf_list_free(struct strbuf **); 471 472/** 473 * Launch the user preferred editor to edit a file and fill the buffer 474 * with the file's contents upon the user completing their editing. The 475 * third argument can be used to set the environment which the editor is 476 * run in. If the buffer is NULL the editor is launched as usual but the 477 * file's contents are not read into the buffer upon completion. 478 */ 479externintlaunch_editor(const char*path,struct strbuf *buffer,const char*const*env); 480 481externvoidstrbuf_add_lines(struct strbuf *sb,const char*prefix,const char*buf,size_t size); 482 483/** 484 * Append s to sb, with the characters '<', '>', '&' and '"' converted 485 * into XML entities. 486 */ 487externvoidstrbuf_addstr_xml_quoted(struct strbuf *sb,const char*s); 488 489staticinlinevoidstrbuf_complete_line(struct strbuf *sb) 490{ 491if(sb->len && sb->buf[sb->len -1] !='\n') 492strbuf_addch(sb,'\n'); 493} 494 495externintstrbuf_branchname(struct strbuf *sb,const char*name); 496externintstrbuf_check_branch_ref(struct strbuf *sb,const char*name); 497 498externvoidstrbuf_addstr_urlencode(struct strbuf *,const char*, 499int reserved); 500 501__attribute__((format(printf,1,2))) 502externintprintf_ln(const char*fmt, ...); 503__attribute__((format(printf,2,3))) 504externintfprintf_ln(FILE*fp,const char*fmt, ...); 505 506char*xstrdup_tolower(const char*); 507 508/** 509 * Create a newly allocated string using printf format. You can do this easily 510 * with a strbuf, but this provides a shortcut to save a few lines. 511 */ 512__attribute__((format(printf,1,0))) 513char*xstrvfmt(const char*fmt,va_list ap); 514__attribute__((format(printf,1,2))) 515char*xstrfmt(const char*fmt, ...); 516 517#endif/* STRBUF_H */