| 1 | /* |
| 2 | * LibXDiff by Davide Libenzi ( File Differential Library ) |
| 3 | * Copyright (C) 2003 Davide Libenzi |
| 4 | * |
| 5 | * This library is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU Lesser General Public |
| 7 | * License as published by the Free Software Foundation; either |
| 8 | * version 2.1 of the License, or (at your option) any later version. |
| 9 | * |
| 10 | * This library is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * Lesser General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU Lesser General Public |
| 16 | * License along with this library; if not, see |
| 17 | * <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | * Davide Libenzi <davidel@xmailserver.org> |
| 20 | * |
| 21 | */ |
| 22 | |
| 23 | #include "xinclude.h" |
| 24 | |
| 25 | |
| 26 | uint64_t xdl_bogosqrt(uint64_t n) { |
| 27 | uint64_t i; |
| 28 | |
| 29 | /* |
| 30 | * Classical integer square root approximation using shifts. |
| 31 | */ |
| 32 | for (i = 1; n > 0; n >>= 2) |
| 33 | i <<= 1; |
| 34 | |
| 35 | return i; |
| 36 | } |
| 37 | |
| 38 | |
| 39 | int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize, |
| 40 | xdemitcb_t *ecb) { |
| 41 | int i = 2; |
| 42 | mmbuffer_t mb[3]; |
| 43 | |
| 44 | mb[0].ptr = (char *) pre; |
| 45 | mb[0].size = psize; |
| 46 | mb[1].ptr = (char *) rec; |
| 47 | mb[1].size = size; |
| 48 | if (size > 0 && rec[size - 1] != '\n') { |
| 49 | mb[2].ptr = (char *) "\n\\ No newline at end of file\n"; |
| 50 | mb[2].size = strlen(mb[2].ptr); |
| 51 | i++; |
| 52 | } |
| 53 | if (ecb->out_line(ecb->priv, mb, i) < 0) { |
| 54 | |
| 55 | return -1; |
| 56 | } |
| 57 | |
| 58 | return 0; |
| 59 | } |
| 60 | |
| 61 | void *xdl_mmfile_first(mmfile_t *mmf, long *size) |
| 62 | { |
| 63 | *size = mmf->size; |
| 64 | return mmf->ptr; |
| 65 | } |
| 66 | |
| 67 | |
| 68 | long xdl_mmfile_size(mmfile_t *mmf) |
| 69 | { |
| 70 | return mmf->size; |
| 71 | } |
| 72 | |
| 73 | |
| 74 | int xdl_cha_init(chastore_t *cha, long isize, long icount) { |
| 75 | |
| 76 | cha->head = cha->tail = NULL; |
| 77 | cha->isize = isize; |
| 78 | cha->nsize = icount * isize; |
| 79 | cha->ancur = cha->sncur = NULL; |
| 80 | cha->scurr = 0; |
| 81 | |
| 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | |
| 86 | void xdl_cha_free(chastore_t *cha) { |
| 87 | chanode_t *cur, *tmp; |
| 88 | |
| 89 | for (cur = cha->head; (tmp = cur) != NULL;) { |
| 90 | cur = cur->next; |
| 91 | xdl_free(tmp); |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | |
| 96 | void *xdl_cha_alloc(chastore_t *cha) { |
| 97 | chanode_t *ancur; |
| 98 | void *data; |
| 99 | |
| 100 | if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) { |
| 101 | if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) { |
| 102 | |
| 103 | return NULL; |
| 104 | } |
| 105 | ancur->icurr = 0; |
| 106 | ancur->next = NULL; |
| 107 | if (cha->tail) |
| 108 | cha->tail->next = ancur; |
| 109 | if (!cha->head) |
| 110 | cha->head = ancur; |
| 111 | cha->tail = ancur; |
| 112 | cha->ancur = ancur; |
| 113 | } |
| 114 | |
| 115 | data = (char *) ancur + sizeof(chanode_t) + ancur->icurr; |
| 116 | ancur->icurr += cha->isize; |
| 117 | |
| 118 | return data; |
| 119 | } |
| 120 | |
| 121 | long xdl_guess_lines(mmfile_t *mf, long sample) { |
| 122 | long nl = 0, size, tsize = 0; |
| 123 | char const *data, *cur, *top; |
| 124 | |
| 125 | if ((cur = data = xdl_mmfile_first(mf, &size))) { |
| 126 | for (top = data + size; nl < sample && cur < top; ) { |
| 127 | nl++; |
| 128 | if (!(cur = memchr(cur, '\n', top - cur))) |
| 129 | cur = top; |
| 130 | else |
| 131 | cur++; |
| 132 | } |
| 133 | tsize += (long) (cur - data); |
| 134 | } |
| 135 | |
| 136 | if (nl && tsize) |
| 137 | nl = xdl_mmfile_size(mf) / (tsize / nl); |
| 138 | |
| 139 | return nl + 1; |
| 140 | } |
| 141 | |
| 142 | int xdl_blankline(const char *line, long size, long flags) |
| 143 | { |
| 144 | long i; |
| 145 | |
| 146 | if (!(flags & XDF_WHITESPACE_FLAGS)) |
| 147 | return (size <= 1); |
| 148 | |
| 149 | for (i = 0; i < size && XDL_ISSPACE(line[i]); i++) |
| 150 | ; |
| 151 | |
| 152 | return (i == size); |
| 153 | } |
| 154 | |
| 155 | /* |
| 156 | * Have we eaten everything on the line, except for an optional |
| 157 | * CR at the very end? |
| 158 | */ |
| 159 | static int ends_with_optional_cr(const char *l, long s, long i) |
| 160 | { |
| 161 | int complete = s && l[s-1] == '\n'; |
| 162 | |
| 163 | if (complete) |
| 164 | s--; |
| 165 | if (s == i) |
| 166 | return 1; |
| 167 | /* do not ignore CR at the end of an incomplete line */ |
| 168 | if (complete && s == i + 1 && l[i] == '\r') |
| 169 | return 1; |
| 170 | return 0; |
| 171 | } |
| 172 | |
| 173 | int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags) |
| 174 | { |
| 175 | int i1, i2; |
| 176 | |
| 177 | if (s1 == s2 && !memcmp(l1, l2, s1)) |
| 178 | return 1; |
| 179 | if (!(flags & XDF_WHITESPACE_FLAGS)) |
| 180 | return 0; |
| 181 | |
| 182 | i1 = 0; |
| 183 | i2 = 0; |
| 184 | |
| 185 | /* |
| 186 | * -w matches everything that matches with -b, and -b in turn |
| 187 | * matches everything that matches with --ignore-space-at-eol, |
| 188 | * which in turn matches everything that matches with --ignore-cr-at-eol. |
| 189 | * |
| 190 | * Each flavor of ignoring needs different logic to skip whitespaces |
| 191 | * while we have both sides to compare. |
| 192 | */ |
| 193 | if (flags & XDF_IGNORE_WHITESPACE) { |
| 194 | goto skip_ws; |
| 195 | while (i1 < s1 && i2 < s2) { |
| 196 | if (l1[i1++] != l2[i2++]) |
| 197 | return 0; |
| 198 | skip_ws: |
| 199 | while (i1 < s1 && XDL_ISSPACE(l1[i1])) |
| 200 | i1++; |
| 201 | while (i2 < s2 && XDL_ISSPACE(l2[i2])) |
| 202 | i2++; |
| 203 | } |
| 204 | } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) { |
| 205 | while (i1 < s1 && i2 < s2) { |
| 206 | if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) { |
| 207 | /* Skip matching spaces and try again */ |
| 208 | while (i1 < s1 && XDL_ISSPACE(l1[i1])) |
| 209 | i1++; |
| 210 | while (i2 < s2 && XDL_ISSPACE(l2[i2])) |
| 211 | i2++; |
| 212 | continue; |
| 213 | } |
| 214 | if (l1[i1++] != l2[i2++]) |
| 215 | return 0; |
| 216 | } |
| 217 | } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) { |
| 218 | while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) { |
| 219 | i1++; |
| 220 | i2++; |
| 221 | } |
| 222 | } else if (flags & XDF_IGNORE_CR_AT_EOL) { |
| 223 | /* Find the first difference and see how the line ends */ |
| 224 | while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) { |
| 225 | i1++; |
| 226 | i2++; |
| 227 | } |
| 228 | return (ends_with_optional_cr(l1, s1, i1) && |
| 229 | ends_with_optional_cr(l2, s2, i2)); |
| 230 | } |
| 231 | |
| 232 | /* |
| 233 | * After running out of one side, the remaining side must have |
| 234 | * nothing but whitespace for the lines to match. Note that |
| 235 | * ignore-whitespace-at-eol case may break out of the loop |
| 236 | * while there still are characters remaining on both lines. |
| 237 | */ |
| 238 | if (i1 < s1) { |
| 239 | while (i1 < s1 && XDL_ISSPACE(l1[i1])) |
| 240 | i1++; |
| 241 | if (s1 != i1) |
| 242 | return 0; |
| 243 | } |
| 244 | if (i2 < s2) { |
| 245 | while (i2 < s2 && XDL_ISSPACE(l2[i2])) |
| 246 | i2++; |
| 247 | return (s2 == i2); |
| 248 | } |
| 249 | return 1; |
| 250 | } |
| 251 | |
| 252 | uint64_t xdl_hash_record_with_whitespace(uint8_t const **data, |
| 253 | uint8_t const *top, uint64_t flags) { |
| 254 | uint64_t ha = 5381; |
| 255 | uint8_t const *ptr = *data; |
| 256 | bool cr_at_eol_only = (flags & XDF_WHITESPACE_FLAGS) == XDF_IGNORE_CR_AT_EOL; |
| 257 | |
| 258 | for (; ptr < top && *ptr != '\n'; ptr++) { |
| 259 | if (cr_at_eol_only) { |
| 260 | /* do not ignore CR at the end of an incomplete line */ |
| 261 | if (*ptr == '\r' && |
| 262 | (ptr + 1 < top && ptr[1] == '\n')) |
| 263 | continue; |
| 264 | } |
| 265 | else if (XDL_ISSPACE(*ptr)) { |
| 266 | const uint8_t *ptr2 = ptr; |
| 267 | bool at_eol; |
| 268 | while (ptr + 1 < top && XDL_ISSPACE(ptr[1]) |
| 269 | && ptr[1] != '\n') |
| 270 | ptr++; |
| 271 | at_eol = (top <= ptr + 1 || ptr[1] == '\n'); |
| 272 | if (flags & XDF_IGNORE_WHITESPACE) |
| 273 | ; /* already handled */ |
| 274 | else if (flags & XDF_IGNORE_WHITESPACE_CHANGE |
| 275 | && !at_eol) { |
| 276 | ha += (ha << 5); |
| 277 | ha ^= (uint64_t) ' '; |
| 278 | } |
| 279 | else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL |
| 280 | && !at_eol) { |
| 281 | while (ptr2 != ptr + 1) { |
| 282 | ha += (ha << 5); |
| 283 | ha ^= (uint64_t) *ptr2; |
| 284 | ptr2++; |
| 285 | } |
| 286 | } |
| 287 | continue; |
| 288 | } |
| 289 | ha += (ha << 5); |
| 290 | ha ^= (uint64_t) *ptr; |
| 291 | } |
| 292 | *data = ptr < top ? ptr + 1: ptr; |
| 293 | |
| 294 | return ha; |
| 295 | } |
| 296 | |
| 297 | /* |
| 298 | * Compiler reassociation barrier: pretend to modify X and Y to disallow |
| 299 | * changing evaluation order with respect to following uses of X and Y. |
| 300 | */ |
| 301 | #ifdef __GNUC__ |
| 302 | #define REASSOC_FENCE(x, y) __asm__("" : "+r"(x), "+r"(y)) |
| 303 | #else |
| 304 | #define REASSOC_FENCE(x, y) |
| 305 | #endif |
| 306 | |
| 307 | uint64_t xdl_hash_record_verbatim(uint8_t const **data, uint8_t const *top) { |
| 308 | uint64_t ha = 5381, c0, c1; |
| 309 | uint8_t const *ptr = *data; |
| 310 | #if 0 |
| 311 | /* |
| 312 | * The baseline form of the optimized loop below. This is the djb2 |
| 313 | * hash (the above function uses a variant with XOR instead of ADD). |
| 314 | */ |
| 315 | for (; ptr < top && *ptr != '\n'; ptr++) { |
| 316 | ha += (ha << 5); |
| 317 | ha += (uint64_t) *ptr; |
| 318 | } |
| 319 | *data = ptr < top ? ptr + 1: ptr; |
| 320 | #else |
| 321 | /* Process two characters per iteration. */ |
| 322 | if (top - ptr >= 2) do { |
| 323 | if ((c0 = ptr[0]) == '\n') { |
| 324 | *data = ptr + 1; |
| 325 | return ha; |
| 326 | } |
| 327 | if ((c1 = ptr[1]) == '\n') { |
| 328 | *data = ptr + 2; |
| 329 | c0 += ha; |
| 330 | REASSOC_FENCE(c0, ha); |
| 331 | ha = ha * 32 + c0; |
| 332 | return ha; |
| 333 | } |
| 334 | /* |
| 335 | * Combine characters C0 and C1 into the hash HA. We have |
| 336 | * HA = (HA * 33 + C0) * 33 + C1, and we want to ensure |
| 337 | * that dependency chain over HA is just one multiplication |
| 338 | * and one addition, i.e. we want to evaluate this as |
| 339 | * HA = HA * 33 * 33 + (C0 * 33 + C1), and likewise prefer |
| 340 | * (C0 * 32 + (C0 + C1)) for the expression in parenthesis. |
| 341 | */ |
| 342 | ha *= 33 * 33; |
| 343 | c1 += c0; |
| 344 | REASSOC_FENCE(c1, c0); |
| 345 | c1 += c0 * 32; |
| 346 | REASSOC_FENCE(c1, ha); |
| 347 | ha += c1; |
| 348 | |
| 349 | ptr += 2; |
| 350 | } while (ptr < top - 1); |
| 351 | *data = top; |
| 352 | if (ptr < top && (c0 = ptr[0]) != '\n') { |
| 353 | c0 += ha; |
| 354 | REASSOC_FENCE(c0, ha); |
| 355 | ha = ha * 32 + c0; |
| 356 | } |
| 357 | #endif |
| 358 | return ha; |
| 359 | } |
| 360 | |
| 361 | unsigned int xdl_hashbits(unsigned int size) { |
| 362 | unsigned int val = 1, bits = 0; |
| 363 | |
| 364 | for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++); |
| 365 | return bits ? bits: 1; |
| 366 | } |
| 367 | |
| 368 | |
| 369 | int xdl_num_out(char *out, long val) { |
| 370 | char *ptr, *str = out; |
| 371 | char buf[32]; |
| 372 | |
| 373 | ptr = buf + sizeof(buf) - 1; |
| 374 | *ptr = '\0'; |
| 375 | if (val < 0) { |
| 376 | *--ptr = '-'; |
| 377 | val = -val; |
| 378 | } |
| 379 | for (; val && ptr > buf; val /= 10) |
| 380 | *--ptr = "0123456789"[val % 10]; |
| 381 | if (*ptr) |
| 382 | for (; *ptr; ptr++, str++) |
| 383 | *str = *ptr; |
| 384 | else |
| 385 | *str++ = '0'; |
| 386 | *str = '\0'; |
| 387 | |
| 388 | return str - out; |
| 389 | } |
| 390 | |
| 391 | static int xdl_format_hunk_hdr(long s1, long c1, long s2, long c2, |
| 392 | const char *func, long funclen, |
| 393 | xdemitcb_t *ecb) { |
| 394 | int nb = 0; |
| 395 | mmbuffer_t mb; |
| 396 | char buf[128]; |
| 397 | |
| 398 | memcpy(buf, "@@ -", 4); |
| 399 | nb += 4; |
| 400 | |
| 401 | nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1); |
| 402 | |
| 403 | if (c1 != 1) { |
| 404 | memcpy(buf + nb, ",", 1); |
| 405 | nb += 1; |
| 406 | |
| 407 | nb += xdl_num_out(buf + nb, c1); |
| 408 | } |
| 409 | |
| 410 | memcpy(buf + nb, " +", 2); |
| 411 | nb += 2; |
| 412 | |
| 413 | nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1); |
| 414 | |
| 415 | if (c2 != 1) { |
| 416 | memcpy(buf + nb, ",", 1); |
| 417 | nb += 1; |
| 418 | |
| 419 | nb += xdl_num_out(buf + nb, c2); |
| 420 | } |
| 421 | |
| 422 | memcpy(buf + nb, " @@", 3); |
| 423 | nb += 3; |
| 424 | if (func && funclen) { |
| 425 | buf[nb++] = ' '; |
| 426 | if ((size_t)funclen > sizeof(buf) - nb - 1) |
| 427 | funclen = sizeof(buf) - nb - 1; |
| 428 | memcpy(buf + nb, func, funclen); |
| 429 | nb += funclen; |
| 430 | } |
| 431 | buf[nb++] = '\n'; |
| 432 | |
| 433 | mb.ptr = buf; |
| 434 | mb.size = nb; |
| 435 | if (ecb->out_line(ecb->priv, &mb, 1) < 0) |
| 436 | return -1; |
| 437 | return 0; |
| 438 | } |
| 439 | |
| 440 | int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2, |
| 441 | const char *func, long funclen, |
| 442 | xdemitcb_t *ecb) { |
| 443 | if (!ecb->out_hunk) |
| 444 | return xdl_format_hunk_hdr(s1, c1, s2, c2, func, funclen, ecb); |
| 445 | if (ecb->out_hunk(ecb->priv, |
| 446 | c1 ? s1 : s1 - 1, c1, |
| 447 | c2 ? s2 : s2 - 1, c2, |
| 448 | func, funclen) < 0) |
| 449 | return -1; |
| 450 | return 0; |
| 451 | } |
| 452 | |
| 453 | int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp, |
| 454 | int line1, int count1, int line2, int count2) |
| 455 | { |
| 456 | /* |
| 457 | * This probably does not work outside Git, since |
| 458 | * we have a very simple mmfile structure. |
| 459 | * |
| 460 | * Note: ideally, we would reuse the prepared environment, but |
| 461 | * the libxdiff interface does not (yet) allow for diffing only |
| 462 | * ranges of lines instead of the whole files. |
| 463 | */ |
| 464 | mmfile_t subfile1, subfile2; |
| 465 | xdfenv_t env; |
| 466 | |
| 467 | subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1].ptr; |
| 468 | subfile1.size = (char *)diff_env->xdf1.recs[line1 + count1 - 2].ptr + |
| 469 | diff_env->xdf1.recs[line1 + count1 - 2].size - subfile1.ptr; |
| 470 | subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1].ptr; |
| 471 | subfile2.size = (char *)diff_env->xdf2.recs[line2 + count2 - 2].ptr + |
| 472 | diff_env->xdf2.recs[line2 + count2 - 2].size - subfile2.ptr; |
| 473 | if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0) |
| 474 | return -1; |
| 475 | |
| 476 | memcpy(diff_env->xdf1.changed + line1 - 1, env.xdf1.changed, count1); |
| 477 | memcpy(diff_env->xdf2.changed + line2 - 1, env.xdf2.changed, count2); |
| 478 | |
| 479 | xdl_free_env(&env); |
| 480 | |
| 481 | return 0; |
| 482 | } |
| 483 | |
| 484 | void* xdl_alloc_grow_helper(void *p, long nr, long *alloc, size_t size) |
| 485 | { |
| 486 | void *tmp = NULL; |
| 487 | size_t n = ((LONG_MAX - 16) / 2 >= *alloc) ? 2 * *alloc + 16 : LONG_MAX; |
| 488 | if ((size_t)nr > n) |
| 489 | n = nr; |
| 490 | if (SIZE_MAX / size >= n) |
| 491 | tmp = xdl_realloc(p, n * size); |
| 492 | if (tmp) { |
| 493 | *alloc = n; |
| 494 | } else { |
| 495 | xdl_free(p); |
| 496 | *alloc = 0; |
| 497 | } |
| 498 | return tmp; |
| 499 | } |