diff options
Diffstat (limited to 'third_party/git/diffcore-rename.c')
| -rw-r--r-- | third_party/git/diffcore-rename.c | 733 |
1 files changed, 0 insertions, 733 deletions
diff --git a/third_party/git/diffcore-rename.c b/third_party/git/diffcore-rename.c deleted file mode 100644 index 99e63e90f89a..000000000000 --- a/third_party/git/diffcore-rename.c +++ /dev/null @@ -1,733 +0,0 @@ -/* - * - * Copyright (C) 2005 Junio C Hamano - */ -#include "cache.h" -#include "diff.h" -#include "diffcore.h" -#include "object-store.h" -#include "hashmap.h" -#include "progress.h" -#include "promisor-remote.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 = first + ((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) - MOVE_ARRAY(rename_dst + first + 1, rename_dst + first, - rename_dst_nr - first - 1); - 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 = first + ((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) - MOVE_ARRAY(rename_src + first + 1, rename_src + first, - rename_src_nr - first - 1); - 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; -}; - -struct prefetch_options { - struct repository *repo; - int skip_unmodified; -}; -static void prefetch(void *prefetch_options) -{ - struct prefetch_options *options = prefetch_options; - int i; - struct oid_array to_fetch = OID_ARRAY_INIT; - - for (i = 0; i < rename_dst_nr; i++) { - if (rename_dst[i].pair) - /* - * The loop in diffcore_rename() will not need these - * blobs, so skip prefetching. - */ - continue; /* already found exact match */ - diff_add_if_missing(options->repo, &to_fetch, - rename_dst[i].two); - } - for (i = 0; i < rename_src_nr; i++) { - if (options->skip_unmodified && - diff_unmodified_pair(rename_src[i].p)) - /* - * The loop in diffcore_rename() will not need these - * blobs, so skip prefetching. - */ - continue; - diff_add_if_missing(options->repo, &to_fetch, - rename_src[i].p->one); - } - promisor_remote_get_direct(options->repo, to_fetch.oid, to_fetch.nr); - oid_array_clear(&to_fetch); -} - -static int estimate_similarity(struct repository *r, - struct diff_filespec *src, - struct diff_filespec *dst, - int minimum_score, - int skip_unmodified) -{ - /* 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; - struct diff_populate_filespec_options dpf_options = { - .check_size_only = 1 - }; - struct prefetch_options prefetch_options = {r, skip_unmodified}; - - if (r == the_repository && has_promisor_remote()) { - dpf_options.missing_object_cb = prefetch; - dpf_options.missing_object_data = &prefetch_options; - } - - /* 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(r, src, &dpf_options)) - return 0; - if (!dst->cnt_data && - diff_populate_filespec(r, dst, &dpf_options)) - 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; - - dpf_options.check_size_only = 0; - - if (!src->cnt_data && diff_populate_filespec(r, src, &dpf_options)) - return 0; - if (!dst->cnt_data && diff_populate_filespec(r, dst, &dpf_options)) - return 0; - - if (diffcore_count_changes(r, 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 repository *r, - struct diff_filespec *filespec) -{ - if (!filespec->oid_valid) { - if (diff_populate_filespec(r, filespec, NULL)) - return 0; - hash_object_file(r->hash_algo, filespec->data, filespec->size, - "blob", &filespec->oid); - } - return oidhash(&filespec->oid); -} - -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; - unsigned int hash = hash_filespec(options->repo, target); - - /* - * Find the best source match for specified destination. - */ - p = hashmap_get_entry_from_hash(srcs, hash, NULL, - struct file_similarity, entry); - hashmap_for_each_entry_from(srcs, p, entry) { - int score; - struct diff_filespec *source = p->filespec; - - /* False hash collision? */ - if (!oideq(&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 repository *r, - 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->entry, hash_filespec(r, filespec)); - hashmap_add(table, &entry->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(options->repo, - &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_entries(&file_table, struct file_similarity, entry); - - 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 - */ - if (rename_limit <= 0) - rename_limit = 32767; - if ((num_create <= rename_limit || num_src <= rename_limit) && - ((uint64_t)num_create * (uint64_t)num_src - <= (uint64_t)rename_limit * (uint64_t)rename_limit)) - return 0; - - options->needed_rename_limit = - num_src > num_create ? num_src : num_create; - - /* Are we running under -C -C? */ - if (!options->flags.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) && - ((uint64_t)num_create * (uint64_t)num_src - <= (uint64_t)rename_limit * (uint64_t)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 (!options->flags.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 (!options->flags.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_delayed_progress( - _("Performing inexact rename detection"), - (uint64_t)rename_dst_nr * (uint64_t)rename_src_nr); - } - - 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(options->repo, - one, two, - minimum_score, - skip_unmodified); - 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, (uint64_t)(i+1)*(uint64_t)rename_src_nr); - } - stop_progress(&progress); - - /* cost matrix sorted by most to least similar pair */ - STABLE_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; -} |