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| /* | |
| * Copyright (C) 2005 Junio C Hamano | |
| */ | |
| #include "cache.h" | |
| #include "diff.h" | |
| #include "diffcore.h" | |
| #include "hashmap.h" | |
| #include "progress.h" | |
| /* Table of rename/copy destinations */ | |
| static struct diff_rename_dst { | |
| struct diff_filespec *two; | |
| struct diff_filepair *pair; | |
| } *rename_dst; | |
| static int rename_dst_nr, rename_dst_alloc; | |
| static int find_rename_dst(struct diff_filespec *two) | |
| { | |
| int first, last; | |
| first = 0; | |
| last = rename_dst_nr; | |
| while (last > first) { | |
| int next = (last + first) >> 1; | |
| struct diff_rename_dst *dst = &(rename_dst[next]); | |
| int cmp = strcmp(two->path, dst->two->path); | |
| if (!cmp) | |
| return next; | |
| if (cmp < 0) { | |
| last = next; | |
| continue; | |
| } | |
| first = next+1; | |
| } | |
| return -first - 1; | |
| } | |
| static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two) | |
| { | |
| int ofs = find_rename_dst(two); | |
| return ofs < 0 ? NULL : &rename_dst[ofs]; | |
| } | |
| /* | |
| * Returns 0 on success, -1 if we found a duplicate. | |
| */ | |
| static int add_rename_dst(struct diff_filespec *two) | |
| { | |
| int first = find_rename_dst(two); | |
| if (first >= 0) | |
| return -1; | |
| first = -first - 1; | |
| /* insert to make it at "first" */ | |
| ALLOC_GROW(rename_dst, rename_dst_nr + 1, rename_dst_alloc); | |
| rename_dst_nr++; | |
| if (first < rename_dst_nr) | |
| memmove(rename_dst + first + 1, rename_dst + first, | |
| (rename_dst_nr - first - 1) * sizeof(*rename_dst)); | |
| rename_dst[first].two = alloc_filespec(two->path); | |
| fill_filespec(rename_dst[first].two, &two->oid, two->oid_valid, | |
| two->mode); | |
| rename_dst[first].pair = NULL; | |
| return 0; | |
| } | |
| /* Table of rename/copy src files */ | |
| static struct diff_rename_src { | |
| struct diff_filepair *p; | |
| unsigned short score; /* to remember the break score */ | |
| } *rename_src; | |
| static int rename_src_nr, rename_src_alloc; | |
| static struct diff_rename_src *register_rename_src(struct diff_filepair *p) | |
| { | |
| int first, last; | |
| struct diff_filespec *one = p->one; | |
| unsigned short score = p->score; | |
| first = 0; | |
| last = rename_src_nr; | |
| while (last > first) { | |
| int next = (last + first) >> 1; | |
| struct diff_rename_src *src = &(rename_src[next]); | |
| int cmp = strcmp(one->path, src->p->one->path); | |
| if (!cmp) | |
| return src; | |
| if (cmp < 0) { | |
| last = next; | |
| continue; | |
| } | |
| first = next+1; | |
| } | |
| /* insert to make it at "first" */ | |
| ALLOC_GROW(rename_src, rename_src_nr + 1, rename_src_alloc); | |
| rename_src_nr++; | |
| if (first < rename_src_nr) | |
| memmove(rename_src + first + 1, rename_src + first, | |
| (rename_src_nr - first - 1) * sizeof(*rename_src)); | |
| rename_src[first].p = p; | |
| rename_src[first].score = score; | |
| return &(rename_src[first]); | |
| } | |
| static int basename_same(struct diff_filespec *src, struct diff_filespec *dst) | |
| { | |
| int src_len = strlen(src->path), dst_len = strlen(dst->path); | |
| while (src_len && dst_len) { | |
| char c1 = src->path[--src_len]; | |
| char c2 = dst->path[--dst_len]; | |
| if (c1 != c2) | |
| return 0; | |
| if (c1 == '/') | |
| return 1; | |
| } | |
| return (!src_len || src->path[src_len - 1] == '/') && | |
| (!dst_len || dst->path[dst_len - 1] == '/'); | |
| } | |
| struct diff_score { | |
| int src; /* index in rename_src */ | |
| int dst; /* index in rename_dst */ | |
| unsigned short score; | |
| short name_score; | |
| }; | |
| static int estimate_similarity(struct diff_filespec *src, | |
| struct diff_filespec *dst, | |
| int minimum_score) | |
| { | |
| /* src points at a file that existed in the original tree (or | |
| * optionally a file in the destination tree) and dst points | |
| * at a newly created file. They may be quite similar, in which | |
| * case we want to say src is renamed to dst or src is copied into | |
| * dst, and then some edit has been applied to dst. | |
| * | |
| * Compare them and return how similar they are, representing | |
| * the score as an integer between 0 and MAX_SCORE. | |
| * | |
| * When there is an exact match, it is considered a better | |
| * match than anything else; the destination does not even | |
| * call into this function in that case. | |
| */ | |
| unsigned long max_size, delta_size, base_size, src_copied, literal_added; | |
| int score; | |
| /* We deal only with regular files. Symlink renames are handled | |
| * only when they are exact matches --- in other words, no edits | |
| * after renaming. | |
| */ | |
| if (!S_ISREG(src->mode) || !S_ISREG(dst->mode)) | |
| return 0; | |
| /* | |
| * Need to check that source and destination sizes are | |
| * filled in before comparing them. | |
| * | |
| * If we already have "cnt_data" filled in, we know it's | |
| * all good (avoid checking the size for zero, as that | |
| * is a possible size - we really should have a flag to | |
| * say whether the size is valid or not!) | |
| */ | |
| if (!src->cnt_data && | |
| diff_populate_filespec(src, CHECK_SIZE_ONLY)) | |
| return 0; | |
| if (!dst->cnt_data && | |
| diff_populate_filespec(dst, CHECK_SIZE_ONLY)) | |
| return 0; | |
| max_size = ((src->size > dst->size) ? src->size : dst->size); | |
| base_size = ((src->size < dst->size) ? src->size : dst->size); | |
| delta_size = max_size - base_size; | |
| /* We would not consider edits that change the file size so | |
| * drastically. delta_size must be smaller than | |
| * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size). | |
| * | |
| * Note that base_size == 0 case is handled here already | |
| * and the final score computation below would not have a | |
| * divide-by-zero issue. | |
| */ | |
| if (max_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE) | |
| return 0; | |
| if (!src->cnt_data && diff_populate_filespec(src, 0)) | |
| return 0; | |
| if (!dst->cnt_data && diff_populate_filespec(dst, 0)) | |
| return 0; | |
| if (diffcore_count_changes(src, dst, | |
| &src->cnt_data, &dst->cnt_data, | |
| &src_copied, &literal_added)) | |
| return 0; | |
| /* How similar are they? | |
| * what percentage of material in dst are from source? | |
| */ | |
| if (!dst->size) | |
| score = 0; /* should not happen */ | |
| else | |
| score = (int)(src_copied * MAX_SCORE / max_size); | |
| return score; | |
| } | |
| static void record_rename_pair(int dst_index, int src_index, int score) | |
| { | |
| struct diff_filespec *src, *dst; | |
| struct diff_filepair *dp; | |
| if (rename_dst[dst_index].pair) | |
| die("internal error: dst already matched."); | |
| src = rename_src[src_index].p->one; | |
| src->rename_used++; | |
| src->count++; | |
| dst = rename_dst[dst_index].two; | |
| dst->count++; | |
| dp = diff_queue(NULL, src, dst); | |
| dp->renamed_pair = 1; | |
| if (!strcmp(src->path, dst->path)) | |
| dp->score = rename_src[src_index].score; | |
| else | |
| dp->score = score; | |
| rename_dst[dst_index].pair = dp; | |
| } | |
| /* | |
| * We sort the rename similarity matrix with the score, in descending | |
| * order (the most similar first). | |
| */ | |
| static int score_compare(const void *a_, const void *b_) | |
| { | |
| const struct diff_score *a = a_, *b = b_; | |
| /* sink the unused ones to the bottom */ | |
| if (a->dst < 0) | |
| return (0 <= b->dst); | |
| else if (b->dst < 0) | |
| return -1; | |
| if (a->score == b->score) | |
| return b->name_score - a->name_score; | |
| return b->score - a->score; | |
| } | |
| struct file_similarity { | |
| struct hashmap_entry entry; | |
| int index; | |
| struct diff_filespec *filespec; | |
| }; | |
| static unsigned int hash_filespec(struct diff_filespec *filespec) | |
| { | |
| if (!filespec->oid_valid) { | |
| if (diff_populate_filespec(filespec, 0)) | |
| return 0; | |
| hash_sha1_file(filespec->data, filespec->size, "blob", | |
| filespec->oid.hash); | |
| } | |
| return sha1hash(filespec->oid.hash); | |
| } | |
| static int find_identical_files(struct hashmap *srcs, | |
| int dst_index, | |
| struct diff_options *options) | |
| { | |
| int renames = 0; | |
| struct diff_filespec *target = rename_dst[dst_index].two; | |
| struct file_similarity *p, *best = NULL; | |
| int i = 100, best_score = -1; | |
| /* | |
| * Find the best source match for specified destination. | |
| */ | |
| p = hashmap_get_from_hash(srcs, hash_filespec(target), NULL); | |
| for (; p; p = hashmap_get_next(srcs, p)) { | |
| int score; | |
| struct diff_filespec *source = p->filespec; | |
| /* False hash collision? */ | |
| if (oidcmp(&source->oid, &target->oid)) | |
| continue; | |
| /* Non-regular files? If so, the modes must match! */ | |
| if (!S_ISREG(source->mode) || !S_ISREG(target->mode)) { | |
| if (source->mode != target->mode) | |
| continue; | |
| } | |
| /* Give higher scores to sources that haven't been used already */ | |
| score = !source->rename_used; | |
| if (source->rename_used && options->detect_rename != DIFF_DETECT_COPY) | |
| continue; | |
| score += basename_same(source, target); | |
| if (score > best_score) { | |
| best = p; | |
| best_score = score; | |
| if (score == 2) | |
| break; | |
| } | |
| /* Too many identical alternatives? Pick one */ | |
| if (!--i) | |
| break; | |
| } | |
| if (best) { | |
| record_rename_pair(dst_index, best->index, MAX_SCORE); | |
| renames++; | |
| } | |
| return renames; | |
| } | |
| static void insert_file_table(struct hashmap *table, int index, struct diff_filespec *filespec) | |
| { | |
| struct file_similarity *entry = xmalloc(sizeof(*entry)); | |
| entry->index = index; | |
| entry->filespec = filespec; | |
| hashmap_entry_init(entry, hash_filespec(filespec)); | |
| hashmap_add(table, entry); | |
| } | |
| /* | |
| * Find exact renames first. | |
| * | |
| * The first round matches up the up-to-date entries, | |
| * and then during the second round we try to match | |
| * cache-dirty entries as well. | |
| */ | |
| static int find_exact_renames(struct diff_options *options) | |
| { | |
| int i, renames = 0; | |
| struct hashmap file_table; | |
| /* Add all sources to the hash table in reverse order, because | |
| * later on they will be retrieved in LIFO order. | |
| */ | |
| hashmap_init(&file_table, NULL, NULL, rename_src_nr); | |
| for (i = rename_src_nr-1; i >= 0; i--) | |
| insert_file_table(&file_table, i, rename_src[i].p->one); | |
| /* Walk the destinations and find best source match */ | |
| for (i = 0; i < rename_dst_nr; i++) | |
| renames += find_identical_files(&file_table, i, options); | |
| /* Free the hash data structure and entries */ | |
| hashmap_free(&file_table, 1); | |
| return renames; | |
| } | |
| #define NUM_CANDIDATE_PER_DST 4 | |
| static void record_if_better(struct diff_score m[], struct diff_score *o) | |
| { | |
| int i, worst; | |
| /* find the worst one */ | |
| worst = 0; | |
| for (i = 1; i < NUM_CANDIDATE_PER_DST; i++) | |
| if (score_compare(&m[i], &m[worst]) > 0) | |
| worst = i; | |
| /* is it better than the worst one? */ | |
| if (score_compare(&m[worst], o) > 0) | |
| m[worst] = *o; | |
| } | |
| /* | |
| * Returns: | |
| * 0 if we are under the limit; | |
| * 1 if we need to disable inexact rename detection; | |
| * 2 if we would be under the limit if we were given -C instead of -C -C. | |
| */ | |
| static int too_many_rename_candidates(int num_create, | |
| struct diff_options *options) | |
| { | |
| int rename_limit = options->rename_limit; | |
| int num_src = rename_src_nr; | |
| int i; | |
| options->needed_rename_limit = 0; | |
| /* | |
| * This basically does a test for the rename matrix not | |
| * growing larger than a "rename_limit" square matrix, ie: | |
| * | |
| * num_create * num_src > rename_limit * rename_limit | |
| * | |
| * but handles the potential overflow case specially (and we | |
| * assume at least 32-bit integers) | |
| */ | |
| if (rename_limit <= 0 || rename_limit > 32767) | |
| rename_limit = 32767; | |
| if ((num_create <= rename_limit || num_src <= rename_limit) && | |
| (num_create * num_src <= rename_limit * rename_limit)) | |
| return 0; | |
| options->needed_rename_limit = | |
| num_src > num_create ? num_src : num_create; | |
| /* Are we running under -C -C? */ | |
| if (!DIFF_OPT_TST(options, FIND_COPIES_HARDER)) | |
| return 1; | |
| /* Would we bust the limit if we were running under -C? */ | |
| for (num_src = i = 0; i < rename_src_nr; i++) { | |
| if (diff_unmodified_pair(rename_src[i].p)) | |
| continue; | |
| num_src++; | |
| } | |
| if ((num_create <= rename_limit || num_src <= rename_limit) && | |
| (num_create * num_src <= rename_limit * rename_limit)) | |
| return 2; | |
| return 1; | |
| } | |
| static int find_renames(struct diff_score *mx, int dst_cnt, int minimum_score, int copies) | |
| { | |
| int count = 0, i; | |
| for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) { | |
| struct diff_rename_dst *dst; | |
| if ((mx[i].dst < 0) || | |
| (mx[i].score < minimum_score)) | |
| break; /* there is no more usable pair. */ | |
| dst = &rename_dst[mx[i].dst]; | |
| if (dst->pair) | |
| continue; /* already done, either exact or fuzzy. */ | |
| if (!copies && rename_src[mx[i].src].p->one->rename_used) | |
| continue; | |
| record_rename_pair(mx[i].dst, mx[i].src, mx[i].score); | |
| count++; | |
| } | |
| return count; | |
| } | |
| void diffcore_rename(struct diff_options *options) | |
| { | |
| int detect_rename = options->detect_rename; | |
| int minimum_score = options->rename_score; | |
| struct diff_queue_struct *q = &diff_queued_diff; | |
| struct diff_queue_struct outq; | |
| struct diff_score *mx; | |
| int i, j, rename_count, skip_unmodified = 0; | |
| int num_create, dst_cnt; | |
| struct progress *progress = NULL; | |
| if (!minimum_score) | |
| minimum_score = DEFAULT_RENAME_SCORE; | |
| for (i = 0; i < q->nr; i++) { | |
| struct diff_filepair *p = q->queue[i]; | |
| if (!DIFF_FILE_VALID(p->one)) { | |
| if (!DIFF_FILE_VALID(p->two)) | |
| continue; /* unmerged */ | |
| else if (options->single_follow && | |
| strcmp(options->single_follow, p->two->path)) | |
| continue; /* not interested */ | |
| else if (!DIFF_OPT_TST(options, RENAME_EMPTY) && | |
| is_empty_blob_oid(&p->two->oid)) | |
| continue; | |
| else if (add_rename_dst(p->two) < 0) { | |
| warning("skipping rename detection, detected" | |
| " duplicate destination '%s'", | |
| p->two->path); | |
| goto cleanup; | |
| } | |
| } | |
| else if (!DIFF_OPT_TST(options, RENAME_EMPTY) && | |
| is_empty_blob_oid(&p->one->oid)) | |
| continue; | |
| else if (!DIFF_PAIR_UNMERGED(p) && !DIFF_FILE_VALID(p->two)) { | |
| /* | |
| * If the source is a broken "delete", and | |
| * they did not really want to get broken, | |
| * that means the source actually stays. | |
| * So we increment the "rename_used" score | |
| * by one, to indicate ourselves as a user | |
| */ | |
| if (p->broken_pair && !p->score) | |
| p->one->rename_used++; | |
| register_rename_src(p); | |
| } | |
| else if (detect_rename == DIFF_DETECT_COPY) { | |
| /* | |
| * Increment the "rename_used" score by | |
| * one, to indicate ourselves as a user. | |
| */ | |
| p->one->rename_used++; | |
| register_rename_src(p); | |
| } | |
| } | |
| if (rename_dst_nr == 0 || rename_src_nr == 0) | |
| goto cleanup; /* nothing to do */ | |
| /* | |
| * We really want to cull the candidates list early | |
| * with cheap tests in order to avoid doing deltas. | |
| */ | |
| rename_count = find_exact_renames(options); | |
| /* Did we only want exact renames? */ | |
| if (minimum_score == MAX_SCORE) | |
| goto cleanup; | |
| /* | |
| * Calculate how many renames are left (but all the source | |
| * files still remain as options for rename/copies!) | |
| */ | |
| num_create = (rename_dst_nr - rename_count); | |
| /* All done? */ | |
| if (!num_create) | |
| goto cleanup; | |
| switch (too_many_rename_candidates(num_create, options)) { | |
| case 1: | |
| goto cleanup; | |
| case 2: | |
| options->degraded_cc_to_c = 1; | |
| skip_unmodified = 1; | |
| break; | |
| default: | |
| break; | |
| } | |
| if (options->show_rename_progress) { | |
| progress = start_progress_delay( | |
| _("Performing inexact rename detection"), | |
| rename_dst_nr * rename_src_nr, 50, 1); | |
| } | |
| mx = xcalloc(st_mult(NUM_CANDIDATE_PER_DST, num_create), sizeof(*mx)); | |
| for (dst_cnt = i = 0; i < rename_dst_nr; i++) { | |
| struct diff_filespec *two = rename_dst[i].two; | |
| struct diff_score *m; | |
| if (rename_dst[i].pair) | |
| continue; /* dealt with exact match already. */ | |
| m = &mx[dst_cnt * NUM_CANDIDATE_PER_DST]; | |
| for (j = 0; j < NUM_CANDIDATE_PER_DST; j++) | |
| m[j].dst = -1; | |
| for (j = 0; j < rename_src_nr; j++) { | |
| struct diff_filespec *one = rename_src[j].p->one; | |
| struct diff_score this_src; | |
| if (skip_unmodified && | |
| diff_unmodified_pair(rename_src[j].p)) | |
| continue; | |
| this_src.score = estimate_similarity(one, two, | |
| minimum_score); | |
| this_src.name_score = basename_same(one, two); | |
| this_src.dst = i; | |
| this_src.src = j; | |
| record_if_better(m, &this_src); | |
| /* | |
| * Once we run estimate_similarity, | |
| * We do not need the text anymore. | |
| */ | |
| diff_free_filespec_blob(one); | |
| diff_free_filespec_blob(two); | |
| } | |
| dst_cnt++; | |
| display_progress(progress, (i+1)*rename_src_nr); | |
| } | |
| stop_progress(&progress); | |
| /* cost matrix sorted by most to least similar pair */ | |
| QSORT(mx, dst_cnt * NUM_CANDIDATE_PER_DST, score_compare); | |
| rename_count += find_renames(mx, dst_cnt, minimum_score, 0); | |
| if (detect_rename == DIFF_DETECT_COPY) | |
| rename_count += find_renames(mx, dst_cnt, minimum_score, 1); | |
| free(mx); | |
| cleanup: | |
| /* At this point, we have found some renames and copies and they | |
| * are recorded in rename_dst. The original list is still in *q. | |
| */ | |
| DIFF_QUEUE_CLEAR(&outq); | |
| for (i = 0; i < q->nr; i++) { | |
| struct diff_filepair *p = q->queue[i]; | |
| struct diff_filepair *pair_to_free = NULL; | |
| if (DIFF_PAIR_UNMERGED(p)) { | |
| diff_q(&outq, p); | |
| } | |
| else if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) { | |
| /* | |
| * Creation | |
| * | |
| * We would output this create record if it has | |
| * not been turned into a rename/copy already. | |
| */ | |
| struct diff_rename_dst *dst = locate_rename_dst(p->two); | |
| if (dst && dst->pair) { | |
| diff_q(&outq, dst->pair); | |
| pair_to_free = p; | |
| } | |
| else | |
| /* no matching rename/copy source, so | |
| * record this as a creation. | |
| */ | |
| diff_q(&outq, p); | |
| } | |
| else if (DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two)) { | |
| /* | |
| * Deletion | |
| * | |
| * We would output this delete record if: | |
| * | |
| * (1) this is a broken delete and the counterpart | |
| * broken create remains in the output; or | |
| * (2) this is not a broken delete, and rename_dst | |
| * does not have a rename/copy to move p->one->path | |
| * out of existence. | |
| * | |
| * Otherwise, the counterpart broken create | |
| * has been turned into a rename-edit; or | |
| * delete did not have a matching create to | |
| * begin with. | |
| */ | |
| if (DIFF_PAIR_BROKEN(p)) { | |
| /* broken delete */ | |
| struct diff_rename_dst *dst = locate_rename_dst(p->one); | |
| if (dst && dst->pair) | |
| /* counterpart is now rename/copy */ | |
| pair_to_free = p; | |
| } | |
| else { | |
| if (p->one->rename_used) | |
| /* this path remains */ | |
| pair_to_free = p; | |
| } | |
| if (pair_to_free) | |
| ; | |
| else | |
| diff_q(&outq, p); | |
| } | |
| else if (!diff_unmodified_pair(p)) | |
| /* all the usual ones need to be kept */ | |
| diff_q(&outq, p); | |
| else | |
| /* no need to keep unmodified pairs */ | |
| pair_to_free = p; | |
| if (pair_to_free) | |
| diff_free_filepair(pair_to_free); | |
| } | |
| diff_debug_queue("done copying original", &outq); | |
| free(q->queue); | |
| *q = outq; | |
| diff_debug_queue("done collapsing", q); | |
| for (i = 0; i < rename_dst_nr; i++) | |
| free_filespec(rename_dst[i].two); | |
| FREE_AND_NULL(rename_dst); | |
| rename_dst_nr = rename_dst_alloc = 0; | |
| FREE_AND_NULL(rename_src); | |
| rename_src_nr = rename_src_alloc = 0; | |
| return; | |
| } |