1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490
/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#include "common.h"
#include "diff.h"
#include "git2/config.h"
#include "hashsig.h"
static git_diff_delta *diff_delta__dup(
const git_diff_delta *d, git_pool *pool)
{
git_diff_delta *delta = git__malloc(sizeof(git_diff_delta));
if (!delta)
return NULL;
memcpy(delta, d, sizeof(git_diff_delta));
delta->old_file.path = git_pool_strdup(pool, d->old_file.path);
if (delta->old_file.path == NULL)
goto fail;
if (d->new_file.path != d->old_file.path) {
delta->new_file.path = git_pool_strdup(pool, d->new_file.path);
if (delta->new_file.path == NULL)
goto fail;
} else {
delta->new_file.path = delta->old_file.path;
}
return delta;
fail:
git__free(delta);
return NULL;
}
static git_diff_delta *diff_delta__merge_like_cgit(
const git_diff_delta *a, const git_diff_delta *b, git_pool *pool)
{
git_diff_delta *dup;
/* Emulate C git for merging two diffs (a la 'git diff <sha>').
*
* When C git does a diff between the work dir and a tree, it actually
* diffs with the index but uses the workdir contents. This emulates
* those choices so we can emulate the type of diff.
*
* We have three file descriptions here, let's call them:
* f1 = a->old_file
* f2 = a->new_file AND b->old_file
* f3 = b->new_file
*/
/* if f2 == f3 or f2 is deleted, then just dup the 'a' diff */
if (b->status == GIT_DELTA_UNMODIFIED || a->status == GIT_DELTA_DELETED)
return diff_delta__dup(a, pool);
/* otherwise, base this diff on the 'b' diff */
if ((dup = diff_delta__dup(b, pool)) == NULL)
return NULL;
/* If 'a' status is uninteresting, then we're done */
if (a->status == GIT_DELTA_UNMODIFIED)
return dup;
assert(a->status != GIT_DELTA_UNMODIFIED);
assert(b->status != GIT_DELTA_UNMODIFIED);
/* A cgit exception is that the diff of a file that is only in the
* index (i.e. not in HEAD nor workdir) is given as empty.
*/
if (dup->status == GIT_DELTA_DELETED) {
if (a->status == GIT_DELTA_ADDED)
dup->status = GIT_DELTA_UNMODIFIED;
/* else don't overwrite DELETE status */
} else {
dup->status = a->status;
}
git_oid_cpy(&dup->old_file.oid, &a->old_file.oid);
dup->old_file.mode = a->old_file.mode;
dup->old_file.size = a->old_file.size;
dup->old_file.flags = a->old_file.flags;
return dup;
}
int git_diff_merge(
git_diff_list *onto,
const git_diff_list *from)
{
int error = 0;
git_pool onto_pool;
git_vector onto_new;
git_diff_delta *delta;
bool ignore_case = false;
unsigned int i, j;
assert(onto && from);
if (!from->deltas.length)
return 0;
if (git_vector_init(
&onto_new, onto->deltas.length, git_diff_delta__cmp) < 0 ||
git_pool_init(&onto_pool, 1, 0) < 0)
return -1;
if ((onto->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0 ||
(from->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0)
{
ignore_case = true;
/* This function currently only supports merging diff lists that
* are sorted identically. */
assert((onto->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0 &&
(from->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0);
}
for (i = 0, j = 0; i < onto->deltas.length || j < from->deltas.length; ) {
git_diff_delta *o = GIT_VECTOR_GET(&onto->deltas, i);
const git_diff_delta *f = GIT_VECTOR_GET(&from->deltas, j);
int cmp = !f ? -1 : !o ? 1 : STRCMP_CASESELECT(ignore_case, o->old_file.path, f->old_file.path);
if (cmp < 0) {
delta = diff_delta__dup(o, &onto_pool);
i++;
} else if (cmp > 0) {
delta = diff_delta__dup(f, &onto_pool);
j++;
} else {
delta = diff_delta__merge_like_cgit(o, f, &onto_pool);
i++;
j++;
}
/* the ignore rules for the target may not match the source
* or the result of a merged delta could be skippable...
*/
if (git_diff_delta__should_skip(&onto->opts, delta)) {
git__free(delta);
continue;
}
if ((error = !delta ? -1 : git_vector_insert(&onto_new, delta)) < 0)
break;
}
if (!error) {
git_vector_swap(&onto->deltas, &onto_new);
git_pool_swap(&onto->pool, &onto_pool);
onto->new_src = from->new_src;
/* prefix strings also come from old pool, so recreate those.*/
onto->opts.old_prefix =
git_pool_strdup_safe(&onto->pool, onto->opts.old_prefix);
onto->opts.new_prefix =
git_pool_strdup_safe(&onto->pool, onto->opts.new_prefix);
}
git_vector_foreach(&onto_new, i, delta)
git__free(delta);
git_vector_free(&onto_new);
git_pool_clear(&onto_pool);
return error;
}
#define DEFAULT_THRESHOLD 50
#define DEFAULT_BREAK_REWRITE_THRESHOLD 60
#define DEFAULT_TARGET_LIMIT 200
static int normalize_find_opts(
git_diff_list *diff,
git_diff_find_options *opts,
git_diff_find_options *given)
{
git_config *cfg = NULL;
const char *val;
if (diff->repo != NULL &&
git_repository_config__weakptr(&cfg, diff->repo) < 0)
return -1;
if (given != NULL)
memcpy(opts, given, sizeof(*opts));
else {
git_diff_find_options init = GIT_DIFF_FIND_OPTIONS_INIT;
memmove(opts, &init, sizeof(init));
opts->flags = GIT_DIFF_FIND_RENAMES;
if (git_config_get_string(&val, cfg, "diff.renames") < 0)
giterr_clear();
else if (val &&
(!strcasecmp(val, "copies") || !strcasecmp(val, "copy")))
opts->flags = GIT_DIFF_FIND_RENAMES | GIT_DIFF_FIND_COPIES;
}
GITERR_CHECK_VERSION(opts, GIT_DIFF_FIND_OPTIONS_VERSION, "git_diff_find_options");
/* some flags imply others */
if (opts->flags & GIT_DIFF_FIND_RENAMES_FROM_REWRITES)
opts->flags |= GIT_DIFF_FIND_RENAMES;
if (opts->flags & GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED)
opts->flags |= GIT_DIFF_FIND_COPIES;
#define USE_DEFAULT(X) ((X) == 0 || (X) > 100)
if (USE_DEFAULT(opts->rename_threshold))
opts->rename_threshold = DEFAULT_THRESHOLD;
if (USE_DEFAULT(opts->rename_from_rewrite_threshold))
opts->rename_from_rewrite_threshold = DEFAULT_THRESHOLD;
if (USE_DEFAULT(opts->copy_threshold))
opts->copy_threshold = DEFAULT_THRESHOLD;
if (USE_DEFAULT(opts->break_rewrite_threshold))
opts->break_rewrite_threshold = DEFAULT_BREAK_REWRITE_THRESHOLD;
#undef USE_DEFAULT
if (!opts->target_limit) {
int32_t limit = 0;
opts->target_limit = DEFAULT_TARGET_LIMIT;
if (git_config_get_int32(&limit, cfg, "diff.renameLimit") < 0)
giterr_clear();
else if (limit > 0)
opts->target_limit = limit;
}
return 0;
}
static int apply_splits_and_deletes(git_diff_list *diff, size_t expected_size)
{
git_vector onto = GIT_VECTOR_INIT;
size_t i;
git_diff_delta *delta;
if (git_vector_init(&onto, expected_size, git_diff_delta__cmp) < 0)
return -1;
/* build new delta list without TO_DELETE and splitting TO_SPLIT */
git_vector_foreach(&diff->deltas, i, delta) {
if (delta->status == GIT_DELTA__TO_DELETE)
continue;
if (delta->status == GIT_DELTA__TO_SPLIT) {
git_diff_delta *deleted = diff_delta__dup(delta, &diff->pool);
if (!deleted)
goto on_error;
deleted->status = GIT_DELTA_DELETED;
memset(&deleted->new_file, 0, sizeof(deleted->new_file));
deleted->new_file.path = deleted->old_file.path;
deleted->new_file.flags |= GIT_DIFF_FILE_VALID_OID;
if (git_vector_insert(&onto, deleted) < 0)
goto on_error;
delta->status = GIT_DELTA_ADDED;
memset(&delta->old_file, 0, sizeof(delta->old_file));
delta->old_file.path = delta->new_file.path;
delta->old_file.flags |= GIT_DIFF_FILE_VALID_OID;
}
if (git_vector_insert(&onto, delta) < 0)
goto on_error;
}
/* cannot return an error past this point */
git_vector_foreach(&diff->deltas, i, delta)
if (delta->status == GIT_DELTA__TO_DELETE)
git__free(delta);
/* swap new delta list into place */
git_vector_sort(&onto);
git_vector_swap(&diff->deltas, &onto);
git_vector_free(&onto);
return 0;
on_error:
git_vector_foreach(&onto, i, delta)
git__free(delta);
git_vector_free(&onto);
return -1;
}
typedef struct {
/* array of delta index * 2 + (old_file/new_file) -> file hashes */
git_hashsig *sigs;
} diff_similarity_cache;
static unsigned int calc_similarity(
void *ref, git_diff_file *old_file, git_diff_file *new_file)
{
diff_similarity_cache *cache = ref;
GIT_UNUSED(cache);
if (git_oid_cmp(&old_file->oid, &new_file->oid) == 0)
return 100;
/* TODO: insert actual similarity algo here */
return 0;
}
#define FLAG_SET(opts,flag_name) ((opts.flags & flag_name) != 0)
int git_diff_find_similar(
git_diff_list *diff,
git_diff_find_options *given_opts)
{
unsigned int i, j, similarity;
git_diff_delta *from, *to;
git_diff_find_options opts;
unsigned int tried_targets, num_changes = 0;
git_vector matches = GIT_VECTOR_INIT;
if (normalize_find_opts(diff, &opts, given_opts) < 0)
return -1;
/* first do splits if requested */
if (FLAG_SET(opts, GIT_DIFF_FIND_AND_BREAK_REWRITES)) {
git_vector_foreach(&diff->deltas, i, from) {
if (from->status != GIT_DELTA_MODIFIED)
continue;
/* Right now, this doesn't work right because the similarity
* algorithm isn't actually implemented...
*/
similarity = 100;
/* calc_similarity(NULL, &from->old_file, from->new_file); */
if (similarity < opts.break_rewrite_threshold) {
from->status = GIT_DELTA__TO_SPLIT;
num_changes++;
}
}
/* apply splits as needed */
if (num_changes > 0 &&
apply_splits_and_deletes(
diff, diff->deltas.length + num_changes) < 0)
return -1;
}
/* next find the most similar delta for each rename / copy candidate */
if (git_vector_init(&matches, diff->deltas.length, git_diff_delta__cmp) < 0)
return -1;
git_vector_foreach(&diff->deltas, i, from) {
tried_targets = 0;
git_vector_foreach(&diff->deltas, j, to) {
if (i == j)
continue;
switch (to->status) {
case GIT_DELTA_ADDED:
case GIT_DELTA_UNTRACKED:
case GIT_DELTA_RENAMED:
case GIT_DELTA_COPIED:
break;
default:
/* only the above status values should be checked */
continue;
}
/* skip all but DELETED files unless copy detection is on */
if (from->status != GIT_DELTA_DELETED &&
!FLAG_SET(opts, GIT_DIFF_FIND_COPIES))
continue;
/* don't check UNMODIFIED files as source unless given option */
if (from->status == GIT_DELTA_UNMODIFIED &&
!FLAG_SET(opts, GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED))
continue;
/* cap on maximum files we'll examine */
if (++tried_targets > opts.target_limit)
break;
/* calculate similarity and see if this pair beats the
* similarity score of the current best pair.
*/
similarity = calc_similarity(NULL, &from->old_file, &to->new_file);
if (to->similarity < similarity) {
to->similarity = similarity;
if (git_vector_set(NULL, &matches, j, from) < 0)
return -1;
}
}
}
/* next rewrite the diffs with renames / copies */
num_changes = 0;
git_vector_foreach(&diff->deltas, j, to) {
from = GIT_VECTOR_GET(&matches, j);
if (!from) {
assert(to->similarity == 0);
continue;
}
/* three possible outcomes here:
* 1. old DELETED and if over rename threshold,
* new becomes RENAMED and old goes away
* 2. old was MODIFIED but FIND_RENAMES_FROM_REWRITES is on and
* old is more similar to new than it is to itself, in which
* case, new becomes RENAMED and old becomed ADDED
* 3. otherwise if over copy threshold, new becomes COPIED
*/
if (from->status == GIT_DELTA_DELETED) {
if (to->similarity < opts.rename_threshold) {
to->similarity = 0;
continue;
}
to->status = GIT_DELTA_RENAMED;
memcpy(&to->old_file, &from->old_file, sizeof(to->old_file));
from->status = GIT_DELTA__TO_DELETE;
num_changes++;
continue;
}
if (from->status == GIT_DELTA_MODIFIED &&
FLAG_SET(opts, GIT_DIFF_FIND_RENAMES_FROM_REWRITES) &&
to->similarity > opts.rename_threshold)
{
similarity = 100;
/* calc_similarity(NULL, &from->old_file, from->new_file); */
if (similarity < opts.rename_from_rewrite_threshold) {
to->status = GIT_DELTA_RENAMED;
memcpy(&to->old_file, &from->old_file, sizeof(to->old_file));
from->status = GIT_DELTA_ADDED;
memset(&from->old_file, 0, sizeof(from->old_file));
from->old_file.path = to->old_file.path;
from->old_file.flags |= GIT_DIFF_FILE_VALID_OID;
continue;
}
}
if (to->similarity < opts.copy_threshold) {
to->similarity = 0;
continue;
}
/* convert "to" to a COPIED record */
to->status = GIT_DELTA_COPIED;
memcpy(&to->old_file, &from->old_file, sizeof(to->old_file));
}
git_vector_free(&matches);
if (num_changes > 0) {
assert(num_changes < diff->deltas.length);
if (apply_splits_and_deletes(
diff, diff->deltas.length - num_changes) < 0)
return -1;
}
return 0;
}
#undef FLAG_SET