| /* |
| * 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.hash, 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; |
| unsigned long delta_limit; |
| 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; |
| |
| delta_limit = (unsigned long) |
| (base_size * (MAX_SCORE-minimum_score) / MAX_SCORE); |
| if (diffcore_count_changes(src, dst, |
| &src->cnt_data, &dst->cnt_data, |
| delta_limit, |
| &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, 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_sha1(p->two->oid.hash)) |
| 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_sha1(p->one->oid.hash)) |
| 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, sizeof(*mx), 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(rename_dst); |
| rename_dst = NULL; |
| rename_dst_nr = rename_dst_alloc = 0; |
| free(rename_src); |
| rename_src = NULL; |
| rename_src_nr = rename_src_alloc = 0; |
| return; |
| } |