diff options
Diffstat (limited to 'third_party/git/blame.c')
| -rw-r--r-- | third_party/git/blame.c | 2808 |
1 files changed, 0 insertions, 2808 deletions
diff --git a/third_party/git/blame.c b/third_party/git/blame.c deleted file mode 100644 index 36a2e7ef11..0000000000 --- a/third_party/git/blame.c +++ /dev/null @@ -1,2808 +0,0 @@ -#include "cache.h" -#include "refs.h" -#include "object-store.h" -#include "cache-tree.h" -#include "mergesort.h" -#include "diff.h" -#include "diffcore.h" -#include "tag.h" -#include "blame.h" -#include "alloc.h" -#include "commit-slab.h" - -define_commit_slab(blame_suspects, struct blame_origin *); -static struct blame_suspects blame_suspects; - -struct blame_origin *get_blame_suspects(struct commit *commit) -{ - struct blame_origin **result; - - result = blame_suspects_peek(&blame_suspects, commit); - - return result ? *result : NULL; -} - -static void set_blame_suspects(struct commit *commit, struct blame_origin *origin) -{ - *blame_suspects_at(&blame_suspects, commit) = origin; -} - -void blame_origin_decref(struct blame_origin *o) -{ - if (o && --o->refcnt <= 0) { - struct blame_origin *p, *l = NULL; - if (o->previous) - blame_origin_decref(o->previous); - free(o->file.ptr); - /* Should be present exactly once in commit chain */ - for (p = get_blame_suspects(o->commit); p; l = p, p = p->next) { - if (p == o) { - if (l) - l->next = p->next; - else - set_blame_suspects(o->commit, p->next); - free(o); - return; - } - } - die("internal error in blame_origin_decref"); - } -} - -/* - * Given a commit and a path in it, create a new origin structure. - * The callers that add blame to the scoreboard should use - * get_origin() to obtain shared, refcounted copy instead of calling - * this function directly. - */ -static struct blame_origin *make_origin(struct commit *commit, const char *path) -{ - struct blame_origin *o; - FLEX_ALLOC_STR(o, path, path); - o->commit = commit; - o->refcnt = 1; - o->next = get_blame_suspects(commit); - set_blame_suspects(commit, o); - return o; -} - -/* - * Locate an existing origin or create a new one. - * This moves the origin to front position in the commit util list. - */ -static struct blame_origin *get_origin(struct commit *commit, const char *path) -{ - struct blame_origin *o, *l; - - for (o = get_blame_suspects(commit), l = NULL; o; l = o, o = o->next) { - if (!strcmp(o->path, path)) { - /* bump to front */ - if (l) { - l->next = o->next; - o->next = get_blame_suspects(commit); - set_blame_suspects(commit, o); - } - return blame_origin_incref(o); - } - } - return make_origin(commit, path); -} - - - -static void verify_working_tree_path(struct repository *r, - struct commit *work_tree, const char *path) -{ - struct commit_list *parents; - int pos; - - for (parents = work_tree->parents; parents; parents = parents->next) { - const struct object_id *commit_oid = &parents->item->object.oid; - struct object_id blob_oid; - unsigned short mode; - - if (!get_tree_entry(r, commit_oid, path, &blob_oid, &mode) && - oid_object_info(r, &blob_oid, NULL) == OBJ_BLOB) - return; - } - - pos = index_name_pos(r->index, path, strlen(path)); - if (pos >= 0) - ; /* path is in the index */ - else if (-1 - pos < r->index->cache_nr && - !strcmp(r->index->cache[-1 - pos]->name, path)) - ; /* path is in the index, unmerged */ - else - die("no such path '%s' in HEAD", path); -} - -static struct commit_list **append_parent(struct repository *r, - struct commit_list **tail, - const struct object_id *oid) -{ - struct commit *parent; - - parent = lookup_commit_reference(r, oid); - if (!parent) - die("no such commit %s", oid_to_hex(oid)); - return &commit_list_insert(parent, tail)->next; -} - -static void append_merge_parents(struct repository *r, - struct commit_list **tail) -{ - int merge_head; - struct strbuf line = STRBUF_INIT; - - merge_head = open(git_path_merge_head(r), O_RDONLY); - if (merge_head < 0) { - if (errno == ENOENT) - return; - die("cannot open '%s' for reading", - git_path_merge_head(r)); - } - - while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) { - struct object_id oid; - if (line.len < GIT_SHA1_HEXSZ || get_oid_hex(line.buf, &oid)) - die("unknown line in '%s': %s", - git_path_merge_head(r), line.buf); - tail = append_parent(r, tail, &oid); - } - close(merge_head); - strbuf_release(&line); -} - -/* - * This isn't as simple as passing sb->buf and sb->len, because we - * want to transfer ownership of the buffer to the commit (so we - * must use detach). - */ -static void set_commit_buffer_from_strbuf(struct repository *r, - struct commit *c, - struct strbuf *sb) -{ - size_t len; - void *buf = strbuf_detach(sb, &len); - set_commit_buffer(r, c, buf, len); -} - -/* - * Prepare a dummy commit that represents the work tree (or staged) item. - * Note that annotating work tree item never works in the reverse. - */ -static struct commit *fake_working_tree_commit(struct repository *r, - struct diff_options *opt, - const char *path, - const char *contents_from) -{ - struct commit *commit; - struct blame_origin *origin; - struct commit_list **parent_tail, *parent; - struct object_id head_oid; - struct strbuf buf = STRBUF_INIT; - const char *ident; - time_t now; - int len; - struct cache_entry *ce; - unsigned mode; - struct strbuf msg = STRBUF_INIT; - - repo_read_index(r); - time(&now); - commit = alloc_commit_node(r); - commit->object.parsed = 1; - commit->date = now; - parent_tail = &commit->parents; - - if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL)) - die("no such ref: HEAD"); - - parent_tail = append_parent(r, parent_tail, &head_oid); - append_merge_parents(r, parent_tail); - verify_working_tree_path(r, commit, path); - - origin = make_origin(commit, path); - - ident = fmt_ident("Not Committed Yet", "not.committed.yet", - WANT_BLANK_IDENT, NULL, 0); - strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n"); - for (parent = commit->parents; parent; parent = parent->next) - strbuf_addf(&msg, "parent %s\n", - oid_to_hex(&parent->item->object.oid)); - strbuf_addf(&msg, - "author %s\n" - "committer %s\n\n" - "Version of %s from %s\n", - ident, ident, path, - (!contents_from ? path : - (!strcmp(contents_from, "-") ? "standard input" : contents_from))); - set_commit_buffer_from_strbuf(r, commit, &msg); - - if (!contents_from || strcmp("-", contents_from)) { - struct stat st; - const char *read_from; - char *buf_ptr; - unsigned long buf_len; - - if (contents_from) { - if (stat(contents_from, &st) < 0) - die_errno("Cannot stat '%s'", contents_from); - read_from = contents_from; - } - else { - if (lstat(path, &st) < 0) - die_errno("Cannot lstat '%s'", path); - read_from = path; - } - mode = canon_mode(st.st_mode); - - switch (st.st_mode & S_IFMT) { - case S_IFREG: - if (opt->flags.allow_textconv && - textconv_object(r, read_from, mode, &null_oid, 0, &buf_ptr, &buf_len)) - strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1); - else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size) - die_errno("cannot open or read '%s'", read_from); - break; - case S_IFLNK: - if (strbuf_readlink(&buf, read_from, st.st_size) < 0) - die_errno("cannot readlink '%s'", read_from); - break; - default: - die("unsupported file type %s", read_from); - } - } - else { - /* Reading from stdin */ - mode = 0; - if (strbuf_read(&buf, 0, 0) < 0) - die_errno("failed to read from stdin"); - } - convert_to_git(r->index, path, buf.buf, buf.len, &buf, 0); - origin->file.ptr = buf.buf; - origin->file.size = buf.len; - pretend_object_file(buf.buf, buf.len, OBJ_BLOB, &origin->blob_oid); - - /* - * Read the current index, replace the path entry with - * origin->blob_sha1 without mucking with its mode or type - * bits; we are not going to write this index out -- we just - * want to run "diff-index --cached". - */ - discard_index(r->index); - repo_read_index(r); - - len = strlen(path); - if (!mode) { - int pos = index_name_pos(r->index, path, len); - if (0 <= pos) - mode = r->index->cache[pos]->ce_mode; - else - /* Let's not bother reading from HEAD tree */ - mode = S_IFREG | 0644; - } - ce = make_empty_cache_entry(r->index, len); - oidcpy(&ce->oid, &origin->blob_oid); - memcpy(ce->name, path, len); - ce->ce_flags = create_ce_flags(0); - ce->ce_namelen = len; - ce->ce_mode = create_ce_mode(mode); - add_index_entry(r->index, ce, - ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE); - - cache_tree_invalidate_path(r->index, path); - - return commit; -} - - - -static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b, - xdl_emit_hunk_consume_func_t hunk_func, void *cb_data, int xdl_opts) -{ - xpparam_t xpp = {0}; - xdemitconf_t xecfg = {0}; - xdemitcb_t ecb = {NULL}; - - xpp.flags = xdl_opts; - xecfg.hunk_func = hunk_func; - ecb.priv = cb_data; - return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb); -} - -static const char *get_next_line(const char *start, const char *end) -{ - const char *nl = memchr(start, '\n', end - start); - - return nl ? nl + 1 : end; -} - -static int find_line_starts(int **line_starts, const char *buf, - unsigned long len) -{ - const char *end = buf + len; - const char *p; - int *lineno; - int num = 0; - - for (p = buf; p < end; p = get_next_line(p, end)) - num++; - - ALLOC_ARRAY(*line_starts, num + 1); - lineno = *line_starts; - - for (p = buf; p < end; p = get_next_line(p, end)) - *lineno++ = p - buf; - - *lineno = len; - - return num; -} - -struct fingerprint_entry; - -/* A fingerprint is intended to loosely represent a string, such that two - * fingerprints can be quickly compared to give an indication of the similarity - * of the strings that they represent. - * - * A fingerprint is represented as a multiset of the lower-cased byte pairs in - * the string that it represents. Whitespace is added at each end of the - * string. Whitespace pairs are ignored. Whitespace is converted to '\0'. - * For example, the string "Darth Radar" will be converted to the following - * fingerprint: - * {"\0d", "da", "da", "ar", "ar", "rt", "th", "h\0", "\0r", "ra", "ad", "r\0"} - * - * The similarity between two fingerprints is the size of the intersection of - * their multisets, including repeated elements. See fingerprint_similarity for - * examples. - * - * For ease of implementation, the fingerprint is implemented as a map - * of byte pairs to the count of that byte pair in the string, instead of - * allowing repeated elements in a set. - */ -struct fingerprint { - struct hashmap map; - /* As we know the maximum number of entries in advance, it's - * convenient to store the entries in a single array instead of having - * the hashmap manage the memory. - */ - struct fingerprint_entry *entries; -}; - -/* A byte pair in a fingerprint. Stores the number of times the byte pair - * occurs in the string that the fingerprint represents. - */ -struct fingerprint_entry { - /* The hashmap entry - the hash represents the byte pair in its - * entirety so we don't need to store the byte pair separately. - */ - struct hashmap_entry entry; - /* The number of times the byte pair occurs in the string that the - * fingerprint represents. - */ - int count; -}; - -/* See `struct fingerprint` for an explanation of what a fingerprint is. - * \param result the fingerprint of the string is stored here. This must be - * freed later using free_fingerprint. - * \param line_begin the start of the string - * \param line_end the end of the string - */ -static void get_fingerprint(struct fingerprint *result, - const char *line_begin, - const char *line_end) -{ - unsigned int hash, c0 = 0, c1; - const char *p; - int max_map_entry_count = 1 + line_end - line_begin; - struct fingerprint_entry *entry = xcalloc(max_map_entry_count, - sizeof(struct fingerprint_entry)); - struct fingerprint_entry *found_entry; - - hashmap_init(&result->map, NULL, NULL, max_map_entry_count); - result->entries = entry; - for (p = line_begin; p <= line_end; ++p, c0 = c1) { - /* Always terminate the string with whitespace. - * Normalise whitespace to 0, and normalise letters to - * lower case. This won't work for multibyte characters but at - * worst will match some unrelated characters. - */ - if ((p == line_end) || isspace(*p)) - c1 = 0; - else - c1 = tolower(*p); - hash = c0 | (c1 << 8); - /* Ignore whitespace pairs */ - if (hash == 0) - continue; - hashmap_entry_init(entry, hash); - - found_entry = hashmap_get(&result->map, entry, NULL); - if (found_entry) { - found_entry->count += 1; - } else { - entry->count = 1; - hashmap_add(&result->map, entry); - ++entry; - } - } -} - -static void free_fingerprint(struct fingerprint *f) -{ - hashmap_free(&f->map, 0); - free(f->entries); -} - -/* Calculates the similarity between two fingerprints as the size of the - * intersection of their multisets, including repeated elements. See - * `struct fingerprint` for an explanation of the fingerprint representation. - * The similarity between "cat mat" and "father rather" is 2 because "at" is - * present twice in both strings while the similarity between "tim" and "mit" - * is 0. - */ -static int fingerprint_similarity(struct fingerprint *a, struct fingerprint *b) -{ - int intersection = 0; - struct hashmap_iter iter; - const struct fingerprint_entry *entry_a, *entry_b; - - hashmap_iter_init(&b->map, &iter); - - while ((entry_b = hashmap_iter_next(&iter))) { - if ((entry_a = hashmap_get(&a->map, entry_b, NULL))) { - intersection += entry_a->count < entry_b->count ? - entry_a->count : entry_b->count; - } - } - return intersection; -} - -/* Subtracts byte-pair elements in B from A, modifying A in place. - */ -static void fingerprint_subtract(struct fingerprint *a, struct fingerprint *b) -{ - struct hashmap_iter iter; - struct fingerprint_entry *entry_a; - const struct fingerprint_entry *entry_b; - - hashmap_iter_init(&b->map, &iter); - - while ((entry_b = hashmap_iter_next(&iter))) { - if ((entry_a = hashmap_get(&a->map, entry_b, NULL))) { - if (entry_a->count <= entry_b->count) - hashmap_remove(&a->map, entry_b, NULL); - else - entry_a->count -= entry_b->count; - } - } -} - -/* Calculate fingerprints for a series of lines. - * Puts the fingerprints in the fingerprints array, which must have been - * preallocated to allow storing line_count elements. - */ -static void get_line_fingerprints(struct fingerprint *fingerprints, - const char *content, const int *line_starts, - long first_line, long line_count) -{ - int i; - const char *linestart, *lineend; - - line_starts += first_line; - for (i = 0; i < line_count; ++i) { - linestart = content + line_starts[i]; - lineend = content + line_starts[i + 1]; - get_fingerprint(fingerprints + i, linestart, lineend); - } -} - -static void free_line_fingerprints(struct fingerprint *fingerprints, - int nr_fingerprints) -{ - int i; - - for (i = 0; i < nr_fingerprints; i++) - free_fingerprint(&fingerprints[i]); -} - -/* This contains the data necessary to linearly map a line number in one half - * of a diff chunk to the line in the other half of the diff chunk that is - * closest in terms of its position as a fraction of the length of the chunk. - */ -struct line_number_mapping { - int destination_start, destination_length, - source_start, source_length; -}; - -/* Given a line number in one range, offset and scale it to map it onto the - * other range. - * Essentially this mapping is a simple linear equation but the calculation is - * more complicated to allow performing it with integer operations. - * Another complication is that if a line could map onto many lines in the - * destination range then we want to choose the line at the center of those - * possibilities. - * Example: if the chunk is 2 lines long in A and 10 lines long in B then the - * first 5 lines in B will map onto the first line in the A chunk, while the - * last 5 lines will all map onto the second line in the A chunk. - * Example: if the chunk is 10 lines long in A and 2 lines long in B then line - * 0 in B will map onto line 2 in A, and line 1 in B will map onto line 7 in A. - */ -static int map_line_number(int line_number, - const struct line_number_mapping *mapping) -{ - return ((line_number - mapping->source_start) * 2 + 1) * - mapping->destination_length / - (mapping->source_length * 2) + - mapping->destination_start; -} - -/* Get a pointer to the element storing the similarity between a line in A - * and a line in B. - * - * The similarities are stored in a 2-dimensional array. Each "row" in the - * array contains the similarities for a line in B. The similarities stored in - * a row are the similarities between the line in B and the nearby lines in A. - * To keep the length of each row the same, it is padded out with values of -1 - * where the search range extends beyond the lines in A. - * For example, if max_search_distance_a is 2 and the two sides of a diff chunk - * look like this: - * a | m - * b | n - * c | o - * d | p - * e | q - * Then the similarity array will contain: - * [-1, -1, am, bm, cm, - * -1, an, bn, cn, dn, - * ao, bo, co, do, eo, - * bp, cp, dp, ep, -1, - * cq, dq, eq, -1, -1] - * Where similarities are denoted either by -1 for invalid, or the - * concatenation of the two lines in the diff being compared. - * - * \param similarities array of similarities between lines in A and B - * \param line_a the index of the line in A, in the same frame of reference as - * closest_line_a. - * \param local_line_b the index of the line in B, relative to the first line - * in B that similarities represents. - * \param closest_line_a the index of the line in A that is deemed to be - * closest to local_line_b. This must be in the same - * frame of reference as line_a. This value defines - * where similarities is centered for the line in B. - * \param max_search_distance_a maximum distance in lines from the closest line - * in A for other lines in A for which - * similarities may be calculated. - */ -static int *get_similarity(int *similarities, - int line_a, int local_line_b, - int closest_line_a, int max_search_distance_a) -{ - assert(abs(line_a - closest_line_a) <= - max_search_distance_a); - return similarities + line_a - closest_line_a + - max_search_distance_a + - local_line_b * (max_search_distance_a * 2 + 1); -} - -#define CERTAIN_NOTHING_MATCHES -2 -#define CERTAINTY_NOT_CALCULATED -1 - -/* Given a line in B, first calculate its similarities with nearby lines in A - * if not already calculated, then identify the most similar and second most - * similar lines. The "certainty" is calculated based on those two - * similarities. - * - * \param start_a the index of the first line of the chunk in A - * \param length_a the length in lines of the chunk in A - * \param local_line_b the index of the line in B, relative to the first line - * in the chunk. - * \param fingerprints_a array of fingerprints for the chunk in A - * \param fingerprints_b array of fingerprints for the chunk in B - * \param similarities 2-dimensional array of similarities between lines in A - * and B. See get_similarity() for more details. - * \param certainties array of values indicating how strongly a line in B is - * matched with some line in A. - * \param second_best_result array of absolute indices in A for the second - * closest match of a line in B. - * \param result array of absolute indices in A for the closest match of a line - * in B. - * \param max_search_distance_a maximum distance in lines from the closest line - * in A for other lines in A for which - * similarities may be calculated. - * \param map_line_number_in_b_to_a parameter to map_line_number(). - */ -static void find_best_line_matches( - int start_a, - int length_a, - int start_b, - int local_line_b, - struct fingerprint *fingerprints_a, - struct fingerprint *fingerprints_b, - int *similarities, - int *certainties, - int *second_best_result, - int *result, - const int max_search_distance_a, - const struct line_number_mapping *map_line_number_in_b_to_a) -{ - - int i, search_start, search_end, closest_local_line_a, *similarity, - best_similarity = 0, second_best_similarity = 0, - best_similarity_index = 0, second_best_similarity_index = 0; - - /* certainty has already been calculated so no need to redo the work */ - if (certainties[local_line_b] != CERTAINTY_NOT_CALCULATED) - return; - - closest_local_line_a = map_line_number( - local_line_b + start_b, map_line_number_in_b_to_a) - start_a; - - search_start = closest_local_line_a - max_search_distance_a; - if (search_start < 0) - search_start = 0; - - search_end = closest_local_line_a + max_search_distance_a + 1; - if (search_end > length_a) - search_end = length_a; - - for (i = search_start; i < search_end; ++i) { - similarity = get_similarity(similarities, - i, local_line_b, - closest_local_line_a, - max_search_distance_a); - if (*similarity == -1) { - /* This value will never exceed 10 but assert just in - * case - */ - assert(abs(i - closest_local_line_a) < 1000); - /* scale the similarity by (1000 - distance from - * closest line) to act as a tie break between lines - * that otherwise are equally similar. - */ - *similarity = fingerprint_similarity( - fingerprints_b + local_line_b, - fingerprints_a + i) * - (1000 - abs(i - closest_local_line_a)); - } - if (*similarity > best_similarity) { - second_best_similarity = best_similarity; - second_best_similarity_index = best_similarity_index; - best_similarity = *similarity; - best_similarity_index = i; - } else if (*similarity > second_best_similarity) { - second_best_similarity = *similarity; - second_best_similarity_index = i; - } - } - - if (best_similarity == 0) { - /* this line definitely doesn't match with anything. Mark it - * with this special value so it doesn't get invalidated and - * won't be recalculated. - */ - certainties[local_line_b] = CERTAIN_NOTHING_MATCHES; - result[local_line_b] = -1; - } else { - /* Calculate the certainty with which this line matches. - * If the line matches well with two lines then that reduces - * the certainty. However we still want to prioritise matching - * a line that matches very well with two lines over matching a - * line that matches poorly with one line, hence doubling - * best_similarity. - * This means that if we have - * line X that matches only one line with a score of 3, - * line Y that matches two lines equally with a score of 5, - * and line Z that matches only one line with a score or 2, - * then the lines in order of certainty are X, Y, Z. - */ - certainties[local_line_b] = best_similarity * 2 - - second_best_similarity; - - /* We keep both the best and second best results to allow us to - * check at a later stage of the matching process whether the - * result needs to be invalidated. - */ - result[local_line_b] = start_a + best_similarity_index; - second_best_result[local_line_b] = - start_a + second_best_similarity_index; - } -} - -/* - * This finds the line that we can match with the most confidence, and - * uses it as a partition. It then calls itself on the lines on either side of - * that partition. In this way we avoid lines appearing out of order, and - * retain a sensible line ordering. - * \param start_a index of the first line in A with which lines in B may be - * compared. - * \param start_b index of the first line in B for which matching should be - * done. - * \param length_a number of lines in A with which lines in B may be compared. - * \param length_b number of lines in B for which matching should be done. - * \param fingerprints_a mutable array of fingerprints in A. The first element - * corresponds to the line at start_a. - * \param fingerprints_b array of fingerprints in B. The first element - * corresponds to the line at start_b. - * \param similarities 2-dimensional array of similarities between lines in A - * and B. See get_similarity() for more details. - * \param certainties array of values indicating how strongly a line in B is - * matched with some line in A. - * \param second_best_result array of absolute indices in A for the second - * closest match of a line in B. - * \param result array of absolute indices in A for the closest match of a line - * in B. - * \param max_search_distance_a maximum distance in lines from the closest line - * in A for other lines in A for which - * similarities may be calculated. - * \param max_search_distance_b an upper bound on the greatest possible - * distance between lines in B such that they will - * both be compared with the same line in A - * according to max_search_distance_a. - * \param map_line_number_in_b_to_a parameter to map_line_number(). - */ -static void fuzzy_find_matching_lines_recurse( - int start_a, int start_b, - int length_a, int length_b, - struct fingerprint *fingerprints_a, - struct fingerprint *fingerprints_b, - int *similarities, - int *certainties, - int *second_best_result, - int *result, - int max_search_distance_a, - int max_search_distance_b, - const struct line_number_mapping *map_line_number_in_b_to_a) -{ - int i, invalidate_min, invalidate_max, offset_b, - second_half_start_a, second_half_start_b, - second_half_length_a, second_half_length_b, - most_certain_line_a, most_certain_local_line_b = -1, - most_certain_line_certainty = -1, - closest_local_line_a; - - for (i = 0; i < length_b; ++i) { - find_best_line_matches(start_a, - length_a, - start_b, - i, - fingerprints_a, - fingerprints_b, - similarities, - certainties, - second_best_result, - result, - max_search_distance_a, - map_line_number_in_b_to_a); - - if (certainties[i] > most_certain_line_certainty) { - most_certain_line_certainty = certainties[i]; - most_certain_local_line_b = i; - } - } - - /* No matches. */ - if (most_certain_local_line_b == -1) - return; - - most_certain_line_a = result[most_certain_local_line_b]; - - /* - * Subtract the most certain line's fingerprint in B from the matched - * fingerprint in A. This means that other lines in B can't also match - * the same parts of the line in A. - */ - fingerprint_subtract(fingerprints_a + most_certain_line_a - start_a, - fingerprints_b + most_certain_local_line_b); - - /* Invalidate results that may be affected by the choice of most - * certain line. - */ - invalidate_min = most_certain_local_line_b - max_search_distance_b; - invalidate_max = most_certain_local_line_b + max_search_distance_b + 1; - if (invalidate_min < 0) - invalidate_min = 0; - if (invalidate_max > length_b) - invalidate_max = length_b; - - /* As the fingerprint in A has changed, discard previously calculated - * similarity values with that fingerprint. - */ - for (i = invalidate_min; i < invalidate_max; ++i) { - closest_local_line_a = map_line_number( - i + start_b, map_line_number_in_b_to_a) - start_a; - - /* Check that the lines in A and B are close enough that there - * is a similarity value for them. - */ - if (abs(most_certain_line_a - start_a - closest_local_line_a) > - max_search_distance_a) { - continue; - } - - *get_similarity(similarities, most_certain_line_a - start_a, - i, closest_local_line_a, - max_search_distance_a) = -1; - } - - /* More invalidating of results that may be affected by the choice of - * most certain line. - * Discard the matches for lines in B that are currently matched with a - * line in A such that their ordering contradicts the ordering imposed - * by the choice of most certain line. - */ - for (i = most_certain_local_line_b - 1; i >= invalidate_min; --i) { - /* In this loop we discard results for lines in B that are - * before most-certain-line-B but are matched with a line in A - * that is after most-certain-line-A. - */ - if (certainties[i] >= 0 && - (result[i] >= most_certain_line_a || - second_best_result[i] >= most_certain_line_a)) { - certainties[i] = CERTAINTY_NOT_CALCULATED; - } - } - for (i = most_certain_local_line_b + 1; i < invalidate_max; ++i) { - /* In this loop we discard results for lines in B that are - * after most-certain-line-B but are matched with a line in A - * that is before most-certain-line-A. - */ - if (certainties[i] >= 0 && - (result[i] <= most_certain_line_a || - second_best_result[i] <= most_certain_line_a)) { - certainties[i] = CERTAINTY_NOT_CALCULATED; - } - } - - /* Repeat the matching process for lines before the most certain line. - */ - if (most_certain_local_line_b > 0) { - fuzzy_find_matching_lines_recurse( - start_a, start_b, - most_certain_line_a + 1 - start_a, - most_certain_local_line_b, - fingerprints_a, fingerprints_b, similarities, - certainties, second_best_result, result, - max_search_distance_a, - max_search_distance_b, - map_line_number_in_b_to_a); - } - /* Repeat the matching process for lines after the most certain line. - */ - if (most_certain_local_line_b + 1 < length_b) { - second_half_start_a = most_certain_line_a; - offset_b = most_certain_local_line_b + 1; - second_half_start_b = start_b + offset_b; - second_half_length_a = - length_a + start_a - second_half_start_a; - second_half_length_b = - length_b + start_b - second_half_start_b; - fuzzy_find_matching_lines_recurse( - second_half_start_a, second_half_start_b, - second_half_length_a, second_half_length_b, - fingerprints_a + second_half_start_a - start_a, - fingerprints_b + offset_b, - similarities + - offset_b * (max_search_distance_a * 2 + 1), - certainties + offset_b, - second_best_result + offset_b, result + offset_b, - max_search_distance_a, - max_search_distance_b, - map_line_number_in_b_to_a); - } -} - -/* Find the lines in the parent line range that most closely match the lines in - * the target line range. This is accomplished by matching fingerprints in each - * blame_origin, and choosing the best matches that preserve the line ordering. - * See struct fingerprint for details of fingerprint matching, and - * fuzzy_find_matching_lines_recurse for details of preserving line ordering. - * - * The performance is believed to be O(n log n) in the typical case and O(n^2) - * in a pathological case, where n is the number of lines in the target range. - */ -static int *fuzzy_find_matching_lines(struct blame_origin *parent, - struct blame_origin *target, - int tlno, int parent_slno, int same, - int parent_len) -{ - /* We use the terminology "A" for the left hand side of the diff AKA - * parent, and "B" for the right hand side of the diff AKA target. */ - int start_a = parent_slno; - int length_a = parent_len; - int start_b = tlno; - int length_b = same - tlno; - - struct line_number_mapping map_line_number_in_b_to_a = { - start_a, length_a, start_b, length_b - }; - - struct fingerprint *fingerprints_a = parent->fingerprints; - struct fingerprint *fingerprints_b = target->fingerprints; - - int i, *result, *second_best_result, - *certainties, *similarities, similarity_count; - - /* - * max_search_distance_a means that given a line in B, compare it to - * the line in A that is closest to its position, and the lines in A - * that are no greater than max_search_distance_a lines away from the - * closest line in A. - * - * max_search_distance_b is an upper bound on the greatest possible - * distance between lines in B such that they will both be compared - * with the same line in A according to max_search_distance_a. - */ - int max_search_distance_a = 10, max_search_distance_b; - - if (length_a <= 0) - return NULL; - - if (max_search_distance_a >= length_a) - max_search_distance_a = length_a ? length_a - 1 : 0; - - max_search_distance_b = ((2 * max_search_distance_a + 1) * length_b - - 1) / length_a; - - result = xcalloc(sizeof(int), length_b); - second_best_result = xcalloc(sizeof(int), length_b); - certainties = xcalloc(sizeof(int), length_b); - - /* See get_similarity() for details of similarities. */ - similarity_count = length_b * (max_search_distance_a * 2 + 1); - similarities = xcalloc(sizeof(int), similarity_count); - - for (i = 0; i < length_b; ++i) { - result[i] = -1; - second_best_result[i] = -1; - certainties[i] = CERTAINTY_NOT_CALCULATED; - } - - for (i = 0; i < similarity_count; ++i) - similarities[i] = -1; - - fuzzy_find_matching_lines_recurse(start_a, start_b, - length_a, length_b, - fingerprints_a + start_a, - fingerprints_b + start_b, - similarities, - certainties, - second_best_result, - result, - max_search_distance_a, - max_search_distance_b, - &map_line_number_in_b_to_a); - - free(similarities); - free(certainties); - free(second_best_result); - - return result; -} - -static void fill_origin_fingerprints(struct blame_origin *o) -{ - int *line_starts; - - if (o->fingerprints) - return; - o->num_lines = find_line_starts(&line_starts, o->file.ptr, - o->file.size); - o->fingerprints = xcalloc(sizeof(struct fingerprint), o->num_lines); - get_line_fingerprints(o->fingerprints, o->file.ptr, line_starts, - 0, o->num_lines); - free(line_starts); -} - -static void drop_origin_fingerprints(struct blame_origin *o) -{ - if (o->fingerprints) { - free_line_fingerprints(o->fingerprints, o->num_lines); - o->num_lines = 0; - FREE_AND_NULL(o->fingerprints); - } -} - -/* - * Given an origin, prepare mmfile_t structure to be used by the - * diff machinery - */ -static void fill_origin_blob(struct diff_options *opt, - struct blame_origin *o, mmfile_t *file, - int *num_read_blob, int fill_fingerprints) -{ - if (!o->file.ptr) { - enum object_type type; - unsigned long file_size; - - (*num_read_blob)++; - if (opt->flags.allow_textconv && - textconv_object(opt->repo, o->path, o->mode, - &o->blob_oid, 1, &file->ptr, &file_size)) - ; - else - file->ptr = read_object_file(&o->blob_oid, &type, - &file_size); - file->size = file_size; - - if (!file->ptr) - die("Cannot read blob %s for path %s", - oid_to_hex(&o->blob_oid), - o->path); - o->file = *file; - } - else - *file = o->file; - if (fill_fingerprints) - fill_origin_fingerprints(o); -} - -static void drop_origin_blob(struct blame_origin *o) -{ - FREE_AND_NULL(o->file.ptr); - drop_origin_fingerprints(o); -} - -/* - * Any merge of blames happens on lists of blames that arrived via - * different parents in a single suspect. In this case, we want to - * sort according to the suspect line numbers as opposed to the final - * image line numbers. The function body is somewhat longish because - * it avoids unnecessary writes. - */ - -static struct blame_entry *blame_merge(struct blame_entry *list1, - struct blame_entry *list2) -{ - struct blame_entry *p1 = list1, *p2 = list2, - **tail = &list1; - - if (!p1) - return p2; - if (!p2) - return p1; - - if (p1->s_lno <= p2->s_lno) { - do { - tail = &p1->next; - if ((p1 = *tail) == NULL) { - *tail = p2; - return list1; - } - } while (p1->s_lno <= p2->s_lno); - } - for (;;) { - *tail = p2; - do { - tail = &p2->next; - if ((p2 = *tail) == NULL) { - *tail = p1; - return list1; - } - } while (p1->s_lno > p2->s_lno); - *tail = p1; - do { - tail = &p1->next; - if ((p1 = *tail) == NULL) { - *tail = p2; - return list1; - } - } while (p1->s_lno <= p2->s_lno); - } -} - -static void *get_next_blame(const void *p) -{ - return ((struct blame_entry *)p)->next; -} - -static void set_next_blame(void *p1, void *p2) -{ - ((struct blame_entry *)p1)->next = p2; -} - -/* - * Final image line numbers are all different, so we don't need a - * three-way comparison here. - */ - -static int compare_blame_final(const void *p1, const void *p2) -{ - return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno - ? 1 : -1; -} - -static int compare_blame_suspect(const void *p1, const void *p2) -{ - const struct blame_entry *s1 = p1, *s2 = p2; - /* - * to allow for collating suspects, we sort according to the - * respective pointer value as the primary sorting criterion. - * The actual relation is pretty unimportant as long as it - * establishes a total order. Comparing as integers gives us - * that. - */ - if (s1->suspect != s2->suspect) - return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1; - if (s1->s_lno == s2->s_lno) - return 0; - return s1->s_lno > s2->s_lno ? 1 : -1; -} - -void blame_sort_final(struct blame_scoreboard *sb) -{ - sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame, - compare_blame_final); -} - -static int compare_commits_by_reverse_commit_date(const void *a, - const void *b, - void *c) -{ - return -compare_commits_by_commit_date(a, b, c); -} - -/* - * For debugging -- origin is refcounted, and this asserts that - * we do not underflow. - */ -static void sanity_check_refcnt(struct blame_scoreboard *sb) -{ - int baa = 0; - struct blame_entry *ent; - - for (ent = sb->ent; ent; ent = ent->next) { - /* Nobody should have zero or negative refcnt */ - if (ent->suspect->refcnt <= 0) { - fprintf(stderr, "%s in %s has negative refcnt %d\n", - ent->suspect->path, - oid_to_hex(&ent->suspect->commit->object.oid), - ent->suspect->refcnt); - baa = 1; - } - } - if (baa) - sb->on_sanity_fail(sb, baa); -} - -/* - * If two blame entries that are next to each other came from - * contiguous lines in the same origin (i.e. <commit, path> pair), - * merge them together. - */ -void blame_coalesce(struct blame_scoreboard *sb) -{ - struct blame_entry *ent, *next; - - for (ent = sb->ent; ent && (next = ent->next); ent = next) { - if (ent->suspect == next->suspect && - ent->s_lno + ent->num_lines == next->s_lno && - ent->ignored == next->ignored && - ent->unblamable == next->unblamable) { - ent->num_lines += next->num_lines; - ent->next = next->next; - blame_origin_decref(next->suspect); - free(next); - ent->score = 0; - next = ent; /* again */ - } - } - - if (sb->debug) /* sanity */ - sanity_check_refcnt(sb); -} - -/* - * Merge the given sorted list of blames into a preexisting origin. - * If there were no previous blames to that commit, it is entered into - * the commit priority queue of the score board. - */ - -static void queue_blames(struct blame_scoreboard *sb, struct blame_origin *porigin, - struct blame_entry *sorted) -{ - if (porigin->suspects) - porigin->suspects = blame_merge(porigin->suspects, sorted); - else { - struct blame_origin *o; - for (o = get_blame_suspects(porigin->commit); o; o = o->next) { - if (o->suspects) { - porigin->suspects = sorted; - return; - } - } - porigin->suspects = sorted; - prio_queue_put(&sb->commits, porigin->commit); - } -} - -/* - * Fill the blob_sha1 field of an origin if it hasn't, so that later - * call to fill_origin_blob() can use it to locate the data. blob_sha1 - * for an origin is also used to pass the blame for the entire file to - * the parent to detect the case where a child's blob is identical to - * that of its parent's. - * - * This also fills origin->mode for corresponding tree path. - */ -static int fill_blob_sha1_and_mode(struct repository *r, - struct blame_origin *origin) -{ - if (!is_null_oid(&origin->blob_oid)) - return 0; - if (get_tree_entry(r, &origin->commit->object.oid, origin->path, &origin->blob_oid, &origin->mode)) - goto error_out; - if (oid_object_info(r, &origin->blob_oid, NULL) != OBJ_BLOB) - goto error_out; - return 0; - error_out: - oidclr(&origin->blob_oid); - origin->mode = S_IFINVALID; - return -1; -} - -/* - * We have an origin -- check if the same path exists in the - * parent and return an origin structure to represent it. - */ -static struct blame_origin *find_origin(struct repository *r, - struct commit *parent, - struct blame_origin *origin) -{ - struct blame_origin *porigin; - struct diff_options diff_opts; - const char *paths[2]; - - /* First check any existing origins */ - for (porigin = get_blame_suspects(parent); porigin; porigin = porigin->next) - if (!strcmp(porigin->path, origin->path)) { - /* - * The same path between origin and its parent - * without renaming -- the most common case. - */ - return blame_origin_incref (porigin); - } - - /* See if the origin->path is different between parent - * and origin first. Most of the time they are the - * same and diff-tree is fairly efficient about this. - */ - repo_diff_setup(r, &diff_opts); - diff_opts.flags.recursive = 1; - diff_opts.detect_rename = 0; - diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; - paths[0] = origin->path; - paths[1] = NULL; - - parse_pathspec(&diff_opts.pathspec, - PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL, - PATHSPEC_LITERAL_PATH, "", paths); - diff_setup_done(&diff_opts); - - if (is_null_oid(&origin->commit->object.oid)) - do_diff_cache(get_commit_tree_oid(parent), &diff_opts); - else - diff_tree_oid(get_commit_tree_oid(parent), - get_commit_tree_oid(origin->commit), - "", &diff_opts); - diffcore_std(&diff_opts); - - if (!diff_queued_diff.nr) { - /* The path is the same as parent */ - porigin = get_origin(parent, origin->path); - oidcpy(&porigin->blob_oid, &origin->blob_oid); - porigin->mode = origin->mode; - } else { - /* - * Since origin->path is a pathspec, if the parent - * commit had it as a directory, we will see a whole - * bunch of deletion of files in the directory that we - * do not care about. - */ - int i; - struct diff_filepair *p = NULL; - for (i = 0; i < diff_queued_diff.nr; i++) { - const char *name; - p = diff_queued_diff.queue[i]; - name = p->one->path ? p->one->path : p->two->path; - if (!strcmp(name, origin->path)) - break; - } - if (!p) - die("internal error in blame::find_origin"); - switch (p->status) { - default: - die("internal error in blame::find_origin (%c)", - p->status); - case 'M': - porigin = get_origin(parent, origin->path); - oidcpy(&porigin->blob_oid, &p->one->oid); - porigin->mode = p->one->mode; - break; - case 'A': - case 'T': - /* Did not exist in parent, or type changed */ - break; - } - } - diff_flush(&diff_opts); - clear_pathspec(&diff_opts.pathspec); - return porigin; -} - -/* - * We have an origin -- find the path that corresponds to it in its - * parent and return an origin structure to represent it. - */ -static struct blame_origin *find_rename(struct repository *r, - struct commit *parent, - struct blame_origin *origin) -{ - struct blame_origin *porigin = NULL; - struct diff_options diff_opts; - int i; - - repo_diff_setup(r, &diff_opts); - diff_opts.flags.recursive = 1; - diff_opts.detect_rename = DIFF_DETECT_RENAME; - diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; - diff_opts.single_follow = origin->path; - diff_setup_done(&diff_opts); - - if (is_null_oid(&origin->commit->object.oid)) - do_diff_cache(get_commit_tree_oid(parent), &diff_opts); - else - diff_tree_oid(get_commit_tree_oid(parent), - get_commit_tree_oid(origin->commit), - "", &diff_opts); - diffcore_std(&diff_opts); - - for (i = 0; i < diff_queued_diff.nr; i++) { - struct diff_filepair *p = diff_queued_diff.queue[i]; - if ((p->status == 'R' || p->status == 'C') && - !strcmp(p->two->path, origin->path)) { - porigin = get_origin(parent, p->one->path); - oidcpy(&porigin->blob_oid, &p->one->oid); - porigin->mode = p->one->mode; - break; - } - } - diff_flush(&diff_opts); - clear_pathspec(&diff_opts.pathspec); - return porigin; -} - -/* - * Append a new blame entry to a given output queue. - */ -static void add_blame_entry(struct blame_entry ***queue, - const struct blame_entry *src) -{ - struct blame_entry *e = xmalloc(sizeof(*e)); - memcpy(e, src, sizeof(*e)); - blame_origin_incref(e->suspect); - - e->next = **queue; - **queue = e; - *queue = &e->next; -} - -/* - * src typically is on-stack; we want to copy the information in it to - * a malloced blame_entry that gets added to the given queue. The - * origin of dst loses a refcnt. - */ -static void dup_entry(struct blame_entry ***queue, - struct blame_entry *dst, struct blame_entry *src) -{ - blame_origin_incref(src->suspect); - blame_origin_decref(dst->suspect); - memcpy(dst, src, sizeof(*src)); - dst->next = **queue; - **queue = dst; - *queue = &dst->next; -} - -const char *blame_nth_line(struct blame_scoreboard *sb, long lno) -{ - return sb->final_buf + sb->lineno[lno]; -} - -/* - * It is known that lines between tlno to same came from parent, and e - * has an overlap with that range. it also is known that parent's - * line plno corresponds to e's line tlno. - * - * <---- e -----> - * <------> - * <------------> - * <------------> - * <------------------> - * - * Split e into potentially three parts; before this chunk, the chunk - * to be blamed for the parent, and after that portion. - */ -static void split_overlap(struct blame_entry *split, - struct blame_entry *e, - int tlno, int plno, int same, - struct blame_origin *parent) -{ - int chunk_end_lno; - int i; - memset(split, 0, sizeof(struct blame_entry [3])); - - for (i = 0; i < 3; i++) { - split[i].ignored = e->ignored; - split[i].unblamable = e->unblamable; - } - - if (e->s_lno < tlno) { - /* there is a pre-chunk part not blamed on parent */ - split[0].suspect = blame_origin_incref(e->suspect); - split[0].lno = e->lno; - split[0].s_lno = e->s_lno; - split[0].num_lines = tlno - e->s_lno; - split[1].lno = e->lno + tlno - e->s_lno; - split[1].s_lno = plno; - } - else { - split[1].lno = e->lno; - split[1].s_lno = plno + (e->s_lno - tlno); - } - - if (same < e->s_lno + e->num_lines) { - /* there is a post-chunk part not blamed on parent */ - split[2].suspect = blame_origin_incref(e->suspect); - split[2].lno = e->lno + (same - e->s_lno); - split[2].s_lno = e->s_lno + (same - e->s_lno); - split[2].num_lines = e->s_lno + e->num_lines - same; - chunk_end_lno = split[2].lno; - } - else - chunk_end_lno = e->lno + e->num_lines; - split[1].num_lines = chunk_end_lno - split[1].lno; - - /* - * if it turns out there is nothing to blame the parent for, - * forget about the splitting. !split[1].suspect signals this. - */ - if (split[1].num_lines < 1) - return; - split[1].suspect = blame_origin_incref(parent); -} - -/* - * split_overlap() divided an existing blame e into up to three parts - * in split. Any assigned blame is moved to queue to - * reflect the split. - */ -static void split_blame(struct blame_entry ***blamed, - struct blame_entry ***unblamed, - struct blame_entry *split, - struct blame_entry *e) -{ - if (split[0].suspect && split[2].suspect) { - /* The first part (reuse storage for the existing entry e) */ - dup_entry(unblamed, e, &split[0]); - - /* The last part -- me */ - add_blame_entry(unblamed, &split[2]); - - /* ... and the middle part -- parent */ - add_blame_entry(blamed, &split[1]); - } - else if (!split[0].suspect && !split[2].suspect) - /* - * The parent covers the entire area; reuse storage for - * e and replace it with the parent. - */ - dup_entry(blamed, e, &split[1]); - else if (split[0].suspect) { - /* me and then parent */ - dup_entry(unblamed, e, &split[0]); - add_blame_entry(blamed, &split[1]); - } - else { - /* parent and then me */ - dup_entry(blamed, e, &split[1]); - add_blame_entry(unblamed, &split[2]); - } -} - -/* - * After splitting the blame, the origins used by the - * on-stack blame_entry should lose one refcnt each. - */ -static void decref_split(struct blame_entry *split) -{ - int i; - - for (i = 0; i < 3; i++) - blame_origin_decref(split[i].suspect); -} - -/* - * reverse_blame reverses the list given in head, appending tail. - * That allows us to build lists in reverse order, then reverse them - * afterwards. This can be faster than building the list in proper - * order right away. The reason is that building in proper order - * requires writing a link in the _previous_ element, while building - * in reverse order just requires placing the list head into the - * _current_ element. - */ - -static struct blame_entry *reverse_blame(struct blame_entry *head, - struct blame_entry *tail) -{ - while (head) { - struct blame_entry *next = head->next; - head->next = tail; - tail = head; - head = next; - } - return tail; -} - -/* - * Splits a blame entry into two entries at 'len' lines. The original 'e' - * consists of len lines, i.e. [e->lno, e->lno + len), and the second part, - * which is returned, consists of the remainder: [e->lno + len, e->lno + - * e->num_lines). The caller needs to sort out the reference counting for the - * new entry's suspect. - */ -static struct blame_entry *split_blame_at(struct blame_entry *e, int len, - struct blame_origin *new_suspect) -{ - struct blame_entry *n = xcalloc(1, sizeof(struct blame_entry)); - - n->suspect = new_suspect; - n->ignored = e->ignored; - n->unblamable = e->unblamable; - n->lno = e->lno + len; - n->s_lno = e->s_lno + len; - n->num_lines = e->num_lines - len; - e->num_lines = len; - e->score = 0; - return n; -} - -struct blame_line_tracker { - int is_parent; - int s_lno; -}; - -static int are_lines_adjacent(struct blame_line_tracker *first, - struct blame_line_tracker *second) -{ - return first->is_parent == second->is_parent && - first->s_lno + 1 == second->s_lno; -} - -static int scan_parent_range(struct fingerprint *p_fps, - struct fingerprint *t_fps, int t_idx, - int from, int nr_lines) -{ - int sim, p_idx; - #define FINGERPRINT_FILE_THRESHOLD 10 - int best_sim_val = FINGERPRINT_FILE_THRESHOLD; - int best_sim_idx = -1; - - for (p_idx = from; p_idx < from + nr_lines; p_idx++) { - sim = fingerprint_similarity(&t_fps[t_idx], &p_fps[p_idx]); - if (sim < best_sim_val) - continue; - /* Break ties with the closest-to-target line number */ - if (sim == best_sim_val && best_sim_idx != -1 && - abs(best_sim_idx - t_idx) < abs(p_idx - t_idx)) - continue; - best_sim_val = sim; - best_sim_idx = p_idx; - } - return best_sim_idx; -} - -/* - * The first pass checks the blame entry (from the target) against the parent's - * diff chunk. If that fails for a line, the second pass tries to match that - * line to any part of parent file. That catches cases where a change was - * broken into two chunks by 'context.' - */ -static void guess_line_blames(struct blame_origin *parent, - struct blame_origin *target, - int tlno, int offset, int same, int parent_len, - struct blame_line_tracker *line_blames) -{ - int i, best_idx, target_idx; - int parent_slno = tlno + offset; - int *fuzzy_matches; - - fuzzy_matches = fuzzy_find_matching_lines(parent, target, - tlno, parent_slno, same, - parent_len); - for (i = 0; i < same - tlno; i++) { - target_idx = tlno + i; - if (fuzzy_matches && fuzzy_matches[i] >= 0) { - best_idx = fuzzy_matches[i]; - } else { - best_idx = scan_parent_range(parent->fingerprints, - target->fingerprints, - target_idx, 0, - parent->num_lines); - } - if (best_idx >= 0) { - line_blames[i].is_parent = 1; - line_blames[i].s_lno = best_idx; - } else { - line_blames[i].is_parent = 0; - line_blames[i].s_lno = target_idx; - } - } - free(fuzzy_matches); -} - -/* - * This decides which parts of a blame entry go to the parent (added to the - * ignoredp list) and which stay with the target (added to the diffp list). The - * actual decision was made in a separate heuristic function, and those answers - * for the lines in 'e' are in line_blames. This consumes e, essentially - * putting it on a list. - * - * Note that the blame entries on the ignoredp list are not necessarily sorted - * with respect to the parent's line numbers yet. - */ -static void ignore_blame_entry(struct blame_entry *e, - struct blame_origin *parent, - struct blame_entry **diffp, - struct blame_entry **ignoredp, - struct blame_line_tracker *line_blames) -{ - int entry_len, nr_lines, i; - - /* - * We carve new entries off the front of e. Each entry comes from a - * contiguous chunk of lines: adjacent lines from the same origin - * (either the parent or the target). - */ - entry_len = 1; - nr_lines = e->num_lines; /* e changes in the loop */ - for (i = 0; i < nr_lines; i++) { - struct blame_entry *next = NULL; - - /* - * We are often adjacent to the next line - only split the blame - * entry when we have to. - */ - if (i + 1 < nr_lines) { - if (are_lines_adjacent(&line_blames[i], - &line_blames[i + 1])) { - entry_len++; - continue; - } - next = split_blame_at(e, entry_len, - blame_origin_incref(e->suspect)); - } - if (line_blames[i].is_parent) { - e->ignored = 1; - blame_origin_decref(e->suspect); - e->suspect = blame_origin_incref(parent); - e->s_lno = line_blames[i - entry_len + 1].s_lno; - e->next = *ignoredp; - *ignoredp = e; - } else { - e->unblamable = 1; - /* e->s_lno is already in the target's address space. */ - e->next = *diffp; - *diffp = e; - } - assert(e->num_lines == entry_len); - e = next; - entry_len = 1; - } - assert(!e); -} - -/* - * Process one hunk from the patch between the current suspect for - * blame_entry e and its parent. This first blames any unfinished - * entries before the chunk (which is where target and parent start - * differing) on the parent, and then splits blame entries at the - * start and at the end of the difference region. Since use of -M and - * -C options may lead to overlapping/duplicate source line number - * ranges, all we can rely on from sorting/merging is the order of the - * first suspect line number. - * - * tlno: line number in the target where this chunk begins - * same: line number in the target where this chunk ends - * offset: add to tlno to get the chunk starting point in the parent - * parent_len: number of lines in the parent chunk - */ -static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq, - int tlno, int offset, int same, int parent_len, - struct blame_origin *parent, - struct blame_origin *target, int ignore_diffs) -{ - struct blame_entry *e = **srcq; - struct blame_entry *samep = NULL, *diffp = NULL, *ignoredp = NULL; - struct blame_line_tracker *line_blames = NULL; - - while (e && e->s_lno < tlno) { - struct blame_entry *next = e->next; - /* - * current record starts before differing portion. If - * it reaches into it, we need to split it up and - * examine the second part separately. - */ - if (e->s_lno + e->num_lines > tlno) { - /* Move second half to a new record */ - struct blame_entry *n; - - n = split_blame_at(e, tlno - e->s_lno, e->suspect); - /* Push new record to diffp */ - n->next = diffp; - diffp = n; - } else - blame_origin_decref(e->suspect); - /* Pass blame for everything before the differing - * chunk to the parent */ - e->suspect = blame_origin_incref(parent); - e->s_lno += offset; - e->next = samep; - samep = e; - e = next; - } - /* - * As we don't know how much of a common stretch after this - * diff will occur, the currently blamed parts are all that we - * can assign to the parent for now. - */ - - if (samep) { - **dstq = reverse_blame(samep, **dstq); - *dstq = &samep->next; - } - /* - * Prepend the split off portions: everything after e starts - * after the blameable portion. - */ - e = reverse_blame(diffp, e); - - /* - * Now retain records on the target while parts are different - * from the parent. - */ - samep = NULL; - diffp = NULL; - - if (ignore_diffs && same - tlno > 0) { - line_blames = xcalloc(sizeof(struct blame_line_tracker), - same - tlno); - guess_line_blames(parent, target, tlno, offset, same, - parent_len, line_blames); - } - - while (e && e->s_lno < same) { - struct blame_entry *next = e->next; - - /* - * If current record extends into sameness, need to split. - */ - if (e->s_lno + e->num_lines > same) { - /* - * Move second half to a new record to be - * processed by later chunks - */ - struct blame_entry *n; - - n = split_blame_at(e, same - e->s_lno, - blame_origin_incref(e->suspect)); - /* Push new record to samep */ - n->next = samep; - samep = n; - } - if (ignore_diffs) { - ignore_blame_entry(e, parent, &diffp, &ignoredp, - line_blames + e->s_lno - tlno); - } else { - e->next = diffp; - diffp = e; - } - e = next; - } - free(line_blames); - if (ignoredp) { - /* - * Note ignoredp is not sorted yet, and thus neither is dstq. - * That list must be sorted before we queue_blames(). We defer - * sorting until after all diff hunks are processed, so that - * guess_line_blames() can pick *any* line in the parent. The - * slight drawback is that we end up sorting all blame entries - * passed to the parent, including those that are unrelated to - * changes made by the ignored commit. - */ - **dstq = reverse_blame(ignoredp, **dstq); - *dstq = &ignoredp->next; - } - **srcq = reverse_blame(diffp, reverse_blame(samep, e)); - /* Move across elements that are in the unblamable portion */ - if (diffp) - *srcq = &diffp->next; -} - -struct blame_chunk_cb_data { - struct blame_origin *parent; - struct blame_origin *target; - long offset; - int ignore_diffs; - struct blame_entry **dstq; - struct blame_entry **srcq; -}; - -/* diff chunks are from parent to target */ -static int blame_chunk_cb(long start_a, long count_a, - long start_b, long count_b, void *data) -{ - struct blame_chunk_cb_data *d = data; - if (start_a - start_b != d->offset) - die("internal error in blame::blame_chunk_cb"); - blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b, - start_b + count_b, count_a, d->parent, d->target, - d->ignore_diffs); - d->offset = start_a + count_a - (start_b + count_b); - return 0; -} - -/* - * We are looking at the origin 'target' and aiming to pass blame - * for the lines it is suspected to its parent. Run diff to find - * which lines came from parent and pass blame for them. - */ -static void pass_blame_to_parent(struct blame_scoreboard *sb, - struct blame_origin *target, - struct blame_origin *parent, int ignore_diffs) -{ - mmfile_t file_p, file_o; - struct blame_chunk_cb_data d; - struct blame_entry *newdest = NULL; - - if (!target->suspects) - return; /* nothing remains for this target */ - - d.parent = parent; - d.target = target; - d.offset = 0; - d.ignore_diffs = ignore_diffs; - d.dstq = &newdest; d.srcq = &target->suspects; - - fill_origin_blob(&sb->revs->diffopt, parent, &file_p, - &sb->num_read_blob, ignore_diffs); - fill_origin_blob(&sb->revs->diffopt, target, &file_o, - &sb->num_read_blob, ignore_diffs); - sb->num_get_patch++; - - if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts)) - die("unable to generate diff (%s -> %s)", - oid_to_hex(&parent->commit->object.oid), - oid_to_hex(&target->commit->object.oid)); - /* The rest are the same as the parent */ - blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, 0, - parent, target, 0); - *d.dstq = NULL; - if (ignore_diffs) - newdest = llist_mergesort(newdest, get_next_blame, - set_next_blame, - compare_blame_suspect); - queue_blames(sb, parent, newdest); - - return; -} - -/* - * The lines in blame_entry after splitting blames many times can become - * very small and trivial, and at some point it becomes pointless to - * blame the parents. E.g. "\t\t}\n\t}\n\n" appears everywhere in any - * ordinary C program, and it is not worth to say it was copied from - * totally unrelated file in the parent. - * - * Compute how trivial the lines in the blame_entry are. - */ -unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e) -{ - unsigned score; - const char *cp, *ep; - - if (e->score) - return e->score; - - score = 1; - cp = blame_nth_line(sb, e->lno); - ep = blame_nth_line(sb, e->lno + e->num_lines); - while (cp < ep) { - unsigned ch = *((unsigned char *)cp); - if (isalnum(ch)) - score++; - cp++; - } - e->score = score; - return score; -} - -/* - * best_so_far[] and potential[] are both a split of an existing blame_entry - * that passes blame to the parent. Maintain best_so_far the best split so - * far, by comparing potential and best_so_far and copying potential into - * bst_so_far as needed. - */ -static void copy_split_if_better(struct blame_scoreboard *sb, - struct blame_entry *best_so_far, - struct blame_entry *potential) -{ - int i; - - if (!potential[1].suspect) - return; - if (best_so_far[1].suspect) { - if (blame_entry_score(sb, &potential[1]) < - blame_entry_score(sb, &best_so_far[1])) - return; - } - - for (i = 0; i < 3; i++) - blame_origin_incref(potential[i].suspect); - decref_split(best_so_far); - memcpy(best_so_far, potential, sizeof(struct blame_entry[3])); -} - -/* - * We are looking at a part of the final image represented by - * ent (tlno and same are offset by ent->s_lno). - * tlno is where we are looking at in the final image. - * up to (but not including) same match preimage. - * plno is where we are looking at in the preimage. - * - * <-------------- final image ----------------------> - * <------ent------> - * ^tlno ^same - * <---------preimage-----> - * ^plno - * - * All line numbers are 0-based. - */ -static void handle_split(struct blame_scoreboard *sb, - struct blame_entry *ent, - int tlno, int plno, int same, - struct blame_origin *parent, - struct blame_entry *split) -{ - if (ent->num_lines <= tlno) - return; - if (tlno < same) { - struct blame_entry potential[3]; - tlno += ent->s_lno; - same += ent->s_lno; - split_overlap(potential, ent, tlno, plno, same, parent); - copy_split_if_better(sb, split, potential); - decref_split(potential); - } -} - -struct handle_split_cb_data { - struct blame_scoreboard *sb; - struct blame_entry *ent; - struct blame_origin *parent; - struct blame_entry *split; - long plno; - long tlno; -}; - -static int handle_split_cb(long start_a, long count_a, - long start_b, long count_b, void *data) -{ - struct handle_split_cb_data *d = data; - handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent, - d->split); - d->plno = start_a + count_a; - d->tlno = start_b + count_b; - return 0; -} - -/* - * Find the lines from parent that are the same as ent so that - * we can pass blames to it. file_p has the blob contents for - * the parent. - */ -static void find_copy_in_blob(struct blame_scoreboard *sb, - struct blame_entry *ent, - struct blame_origin *parent, - struct blame_entry *split, - mmfile_t *file_p) -{ - const char *cp; - mmfile_t file_o; - struct handle_split_cb_data d; - - memset(&d, 0, sizeof(d)); - d.sb = sb; d.ent = ent; d.parent = parent; d.split = split; - /* - * Prepare mmfile that contains only the lines in ent. - */ - cp = blame_nth_line(sb, ent->lno); - file_o.ptr = (char *) cp; - file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp; - - /* - * file_o is a part of final image we are annotating. - * file_p partially may match that image. - */ - memset(split, 0, sizeof(struct blame_entry [3])); - if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts)) - die("unable to generate diff (%s)", - oid_to_hex(&parent->commit->object.oid)); - /* remainder, if any, all match the preimage */ - handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split); -} - -/* Move all blame entries from list *source that have a score smaller - * than score_min to the front of list *small. - * Returns a pointer to the link pointing to the old head of the small list. - */ - -static struct blame_entry **filter_small(struct blame_scoreboard *sb, - struct blame_entry **small, - struct blame_entry **source, - unsigned score_min) -{ - struct blame_entry *p = *source; - struct blame_entry *oldsmall = *small; - while (p) { - if (blame_entry_score(sb, p) <= score_min) { - *small = p; - small = &p->next; - p = *small; - } else { - *source = p; - source = &p->next; - p = *source; - } - } - *small = oldsmall; - *source = NULL; - return small; -} - -/* - * See if lines currently target is suspected for can be attributed to - * parent. - */ -static void find_move_in_parent(struct blame_scoreboard *sb, - struct blame_entry ***blamed, - struct blame_entry **toosmall, - struct blame_origin *target, - struct blame_origin *parent) -{ - struct blame_entry *e, split[3]; - struct blame_entry *unblamed = target->suspects; - struct blame_entry *leftover = NULL; - mmfile_t file_p; - - if (!unblamed) - return; /* nothing remains for this target */ - - fill_origin_blob(&sb->revs->diffopt, parent, &file_p, - &sb->num_read_blob, 0); - if (!file_p.ptr) - return; - - /* At each iteration, unblamed has a NULL-terminated list of - * entries that have not yet been tested for blame. leftover - * contains the reversed list of entries that have been tested - * without being assignable to the parent. - */ - do { - struct blame_entry **unblamedtail = &unblamed; - struct blame_entry *next; - for (e = unblamed; e; e = next) { - next = e->next; - find_copy_in_blob(sb, e, parent, split, &file_p); - if (split[1].suspect && - sb->move_score < blame_entry_score(sb, &split[1])) { - split_blame(blamed, &unblamedtail, split, e); - } else { - e->next = leftover; - leftover = e; - } - decref_split(split); - } - *unblamedtail = NULL; - toosmall = filter_small(sb, toosmall, &unblamed, sb->move_score); - } while (unblamed); - target->suspects = reverse_blame(leftover, NULL); -} - -struct blame_list { - struct blame_entry *ent; - struct blame_entry split[3]; -}; - -/* - * Count the number of entries the target is suspected for, - * and prepare a list of entry and the best split. - */ -static struct blame_list *setup_blame_list(struct blame_entry *unblamed, - int *num_ents_p) -{ - struct blame_entry *e; - int num_ents, i; - struct blame_list *blame_list = NULL; - - for (e = unblamed, num_ents = 0; e; e = e->next) - num_ents++; - if (num_ents) { - blame_list = xcalloc(num_ents, sizeof(struct blame_list)); - for (e = unblamed, i = 0; e; e = e->next) - blame_list[i++].ent = e; - } - *num_ents_p = num_ents; - return blame_list; -} - -/* - * For lines target is suspected for, see if we can find code movement - * across file boundary from the parent commit. porigin is the path - * in the parent we already tried. - */ -static void find_copy_in_parent(struct blame_scoreboard *sb, - struct blame_entry ***blamed, - struct blame_entry **toosmall, - struct blame_origin *target, - struct commit *parent, - struct blame_origin *porigin, - int opt) -{ - struct diff_options diff_opts; - int i, j; - struct blame_list *blame_list; - int num_ents; - struct blame_entry *unblamed = target->suspects; - struct blame_entry *leftover = NULL; - - if (!unblamed) - return; /* nothing remains for this target */ - - repo_diff_setup(sb->repo, &diff_opts); - diff_opts.flags.recursive = 1; - diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; - - diff_setup_done(&diff_opts); - - /* Try "find copies harder" on new path if requested; - * we do not want to use diffcore_rename() actually to - * match things up; find_copies_harder is set only to - * force diff_tree_oid() to feed all filepairs to diff_queue, - * and this code needs to be after diff_setup_done(), which - * usually makes find-copies-harder imply copy detection. - */ - if ((opt & PICKAXE_BLAME_COPY_HARDEST) - || ((opt & PICKAXE_BLAME_COPY_HARDER) - && (!porigin || strcmp(target->path, porigin->path)))) - diff_opts.flags.find_copies_harder = 1; - - if (is_null_oid(&target->commit->object.oid)) - do_diff_cache(get_commit_tree_oid(parent), &diff_opts); - else - diff_tree_oid(get_commit_tree_oid(parent), - get_commit_tree_oid(target->commit), - "", &diff_opts); - - if (!diff_opts.flags.find_copies_harder) - diffcore_std(&diff_opts); - - do { - struct blame_entry **unblamedtail = &unblamed; - blame_list = setup_blame_list(unblamed, &num_ents); - - for (i = 0; i < diff_queued_diff.nr; i++) { - struct diff_filepair *p = diff_queued_diff.queue[i]; - struct blame_origin *norigin; - mmfile_t file_p; - struct blame_entry potential[3]; - - if (!DIFF_FILE_VALID(p->one)) - continue; /* does not exist in parent */ - if (S_ISGITLINK(p->one->mode)) - continue; /* ignore git links */ - if (porigin && !strcmp(p->one->path, porigin->path)) - /* find_move already dealt with this path */ - continue; - - norigin = get_origin(parent, p->one->path); - oidcpy(&norigin->blob_oid, &p->one->oid); - norigin->mode = p->one->mode; - fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, - &sb->num_read_blob, 0); - if (!file_p.ptr) - continue; - - for (j = 0; j < num_ents; j++) { - find_copy_in_blob(sb, blame_list[j].ent, - norigin, potential, &file_p); - copy_split_if_better(sb, blame_list[j].split, - potential); - decref_split(potential); - } - blame_origin_decref(norigin); - } - - for (j = 0; j < num_ents; j++) { - struct blame_entry *split = blame_list[j].split; - if (split[1].suspect && - sb->copy_score < blame_entry_score(sb, &split[1])) { - split_blame(blamed, &unblamedtail, split, - blame_list[j].ent); - } else { - blame_list[j].ent->next = leftover; - leftover = blame_list[j].ent; - } - decref_split(split); - } - free(blame_list); - *unblamedtail = NULL; - toosmall = filter_small(sb, toosmall, &unblamed, sb->copy_score); - } while (unblamed); - target->suspects = reverse_blame(leftover, NULL); - diff_flush(&diff_opts); - clear_pathspec(&diff_opts.pathspec); -} - -/* - * The blobs of origin and porigin exactly match, so everything - * origin is suspected for can be blamed on the parent. - */ -static void pass_whole_blame(struct blame_scoreboard *sb, - struct blame_origin *origin, struct blame_origin *porigin) -{ - struct blame_entry *e, *suspects; - - if (!porigin->file.ptr && origin->file.ptr) { - /* Steal its file */ - porigin->file = origin->file; - origin->file.ptr = NULL; - } - suspects = origin->suspects; - origin->suspects = NULL; - for (e = suspects; e; e = e->next) { - blame_origin_incref(porigin); - blame_origin_decref(e->suspect); - e->suspect = porigin; - } - queue_blames(sb, porigin, suspects); -} - -/* - * We pass blame from the current commit to its parents. We keep saying - * "parent" (and "porigin"), but what we mean is to find scapegoat to - * exonerate ourselves. - */ -static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit, - int reverse) -{ - if (!reverse) { - if (revs->first_parent_only && - commit->parents && - commit->parents->next) { - free_commit_list(commit->parents->next); - commit->parents->next = NULL; - } - return commit->parents; - } - return lookup_decoration(&revs->children, &commit->object); -} - -static int num_scapegoats(struct rev_info *revs, struct commit *commit, int reverse) -{ - struct commit_list *l = first_scapegoat(revs, commit, reverse); - return commit_list_count(l); -} - -/* Distribute collected unsorted blames to the respected sorted lists - * in the various origins. - */ -static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry *blamed) -{ - blamed = llist_mergesort(blamed, get_next_blame, set_next_blame, - compare_blame_suspect); - while (blamed) - { - struct blame_origin *porigin = blamed->suspect; - struct blame_entry *suspects = NULL; - do { - struct blame_entry *next = blamed->next; - blamed->next = suspects; - suspects = blamed; - blamed = next; - } while (blamed && blamed->suspect == porigin); - suspects = reverse_blame(suspects, NULL); - queue_blames(sb, porigin, suspects); - } -} - -#define MAXSG 16 - -static void pass_blame(struct blame_scoreboard *sb, struct blame_origin *origin, int opt) -{ - struct rev_info *revs = sb->revs; - int i, pass, num_sg; - struct commit *commit = origin->commit; - struct commit_list *sg; - struct blame_origin *sg_buf[MAXSG]; - struct blame_origin *porigin, **sg_origin = sg_buf; - struct blame_entry *toosmall = NULL; - struct blame_entry *blames, **blametail = &blames; - - num_sg = num_scapegoats(revs, commit, sb->reverse); - if (!num_sg) - goto finish; - else if (num_sg < ARRAY_SIZE(sg_buf)) - memset(sg_buf, 0, sizeof(sg_buf)); - else - sg_origin = xcalloc(num_sg, sizeof(*sg_origin)); - - /* - * The first pass looks for unrenamed path to optimize for - * common cases, then we look for renames in the second pass. - */ - for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) { - struct blame_origin *(*find)(struct repository *, struct commit *, struct blame_origin *); - find = pass ? find_rename : find_origin; - - for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); - i < num_sg && sg; - sg = sg->next, i++) { - struct commit *p = sg->item; - int j, same; - - if (sg_origin[i]) - continue; - if (parse_commit(p)) - continue; - porigin = find(sb->repo, p, origin); - if (!porigin) - continue; - if (oideq(&porigin->blob_oid, &origin->blob_oid)) { - pass_whole_blame(sb, origin, porigin); - blame_origin_decref(porigin); - goto finish; - } - for (j = same = 0; j < i; j++) - if (sg_origin[j] && - oideq(&sg_origin[j]->blob_oid, &porigin->blob_oid)) { - same = 1; - break; - } - if (!same) - sg_origin[i] = porigin; - else - blame_origin_decref(porigin); - } - } - - sb->num_commits++; - for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); - i < num_sg && sg; - sg = sg->next, i++) { - struct blame_origin *porigin = sg_origin[i]; - if (!porigin) - continue; - if (!origin->previous) { - blame_origin_incref(porigin); - origin->previous = porigin; - } - pass_blame_to_parent(sb, origin, porigin, 0); - if (!origin->suspects) - goto finish; - } - - /* - * Pass remaining suspects for ignored commits to their parents. - */ - if (oidset_contains(&sb->ignore_list, &commit->object.oid)) { - for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); - i < num_sg && sg; - sg = sg->next, i++) { - struct blame_origin *porigin = sg_origin[i]; - - if (!porigin) - continue; - pass_blame_to_parent(sb, origin, porigin, 1); - /* - * Preemptively drop porigin so we can refresh the - * fingerprints if we use the parent again, which can - * occur if you ignore back-to-back commits. - */ - drop_origin_blob(porigin); - if (!origin->suspects) - goto finish; - } - } - - /* - * Optionally find moves in parents' files. - */ - if (opt & PICKAXE_BLAME_MOVE) { - filter_small(sb, &toosmall, &origin->suspects, sb->move_score); - if (origin->suspects) { - for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); - i < num_sg && sg; - sg = sg->next, i++) { - struct blame_origin *porigin = sg_origin[i]; - if (!porigin) - continue; - find_move_in_parent(sb, &blametail, &toosmall, origin, porigin); - if (!origin->suspects) - break; - } - } - } - - /* - * Optionally find copies from parents' files. - */ - if (opt & PICKAXE_BLAME_COPY) { - if (sb->copy_score > sb->move_score) - filter_small(sb, &toosmall, &origin->suspects, sb->copy_score); - else if (sb->copy_score < sb->move_score) { - origin->suspects = blame_merge(origin->suspects, toosmall); - toosmall = NULL; - filter_small(sb, &toosmall, &origin->suspects, sb->copy_score); - } - if (!origin->suspects) - goto finish; - - for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse); - i < num_sg && sg; - sg = sg->next, i++) { - struct blame_origin *porigin = sg_origin[i]; - find_copy_in_parent(sb, &blametail, &toosmall, - origin, sg->item, porigin, opt); - if (!origin->suspects) - goto finish; - } - } - -finish: - *blametail = NULL; - distribute_blame(sb, blames); - /* - * prepend toosmall to origin->suspects - * - * There is no point in sorting: this ends up on a big - * unsorted list in the caller anyway. - */ - if (toosmall) { - struct blame_entry **tail = &toosmall; - while (*tail) - tail = &(*tail)->next; - *tail = origin->suspects; - origin->suspects = toosmall; - } - for (i = 0; i < num_sg; i++) { - if (sg_origin[i]) { - if (!sg_origin[i]->suspects) - drop_origin_blob(sg_origin[i]); - blame_origin_decref(sg_origin[i]); - } - } - drop_origin_blob(origin); - if (sg_buf != sg_origin) - free(sg_origin); -} - -/* - * The main loop -- while we have blobs with lines whose true origin - * is still unknown, pick one blob, and allow its lines to pass blames - * to its parents. */ -void assign_blame(struct blame_scoreboard *sb, int opt) -{ - struct rev_info *revs = sb->revs; - struct commit *commit = prio_queue_get(&sb->commits); - - while (commit) { - struct blame_entry *ent; - struct blame_origin *suspect = get_blame_suspects(commit); - - /* find one suspect to break down */ - while (suspect && !suspect->suspects) - suspect = suspect->next; - - if (!suspect) { - commit = prio_queue_get(&sb->commits); - continue; - } - - assert(commit == suspect->commit); - - /* - * We will use this suspect later in the loop, - * so hold onto it in the meantime. - */ - blame_origin_incref(suspect); - parse_commit(commit); - if (sb->reverse || - (!(commit->object.flags & UNINTERESTING) && - !(revs->max_age != -1 && commit->date < revs->max_age))) - pass_blame(sb, suspect, opt); - else { - commit->object.flags |= UNINTERESTING; - if (commit->object.parsed) - mark_parents_uninteresting(commit); - } - /* treat root commit as boundary */ - if (!commit->parents && !sb->show_root) - commit->object.flags |= UNINTERESTING; - - /* Take responsibility for the remaining entries */ - ent = suspect->suspects; - if (ent) { - suspect->guilty = 1; - for (;;) { - struct blame_entry *next = ent->next; - if (sb->found_guilty_entry) - sb->found_guilty_entry(ent, sb->found_guilty_entry_data); - if (next) { - ent = next; - continue; - } - ent->next = sb->ent; - sb->ent = suspect->suspects; - suspect->suspects = NULL; - break; - } - } - blame_origin_decref(suspect); - - if (sb->debug) /* sanity */ - sanity_check_refcnt(sb); - } -} - -/* - * To allow quick access to the contents of nth line in the - * final image, prepare an index in the scoreboard. - */ -static int prepare_lines(struct blame_scoreboard *sb) -{ - sb->num_lines = find_line_starts(&sb->lineno, sb->final_buf, - sb->final_buf_size); - return sb->num_lines; -} - -static struct commit *find_single_final(struct rev_info *revs, - const char **name_p) -{ - int i; - struct commit *found = NULL; - const char *name = NULL; - - for (i = 0; i < revs->pending.nr; i++) { - struct object *obj = revs->pending.objects[i].item; - if (obj->flags & UNINTERESTING) - continue; - obj = deref_tag(revs->repo, obj, NULL, 0); - if (obj->type != OBJ_COMMIT) - die("Non commit %s?", revs->pending.objects[i].name); - if (found) - die("More than one commit to dig from %s and %s?", - revs->pending.objects[i].name, name); - found = (struct commit *)obj; - name = revs->pending.objects[i].name; - } - if (name_p) - *name_p = xstrdup_or_null(name); - return found; -} - -static struct commit *dwim_reverse_initial(struct rev_info *revs, - const char **name_p) -{ - /* - * DWIM "git blame --reverse ONE -- PATH" as - * "git blame --reverse ONE..HEAD -- PATH" but only do so - * when it makes sense. - */ - struct object *obj; - struct commit *head_commit; - struct object_id head_oid; - - if (revs->pending.nr != 1) - return NULL; - - /* Is that sole rev a committish? */ - obj = revs->pending.objects[0].item; - obj = deref_tag(revs->repo, obj, NULL, 0); - if (obj->type != OBJ_COMMIT) - return NULL; - - /* Do we have HEAD? */ - if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL)) - return NULL; - head_commit = lookup_commit_reference_gently(revs->repo, - &head_oid, 1); - if (!head_commit) - return NULL; - - /* Turn "ONE" into "ONE..HEAD" then */ - obj->flags |= UNINTERESTING; - add_pending_object(revs, &head_commit->object, "HEAD"); - - if (name_p) - *name_p = revs->pending.objects[0].name; - return (struct commit *)obj; -} - -static struct commit *find_single_initial(struct rev_info *revs, - const char **name_p) -{ - int i; - struct commit *found = NULL; - const char *name = NULL; - - /* - * There must be one and only one negative commit, and it must be - * the boundary. - */ - for (i = 0; i < revs->pending.nr; i++) { - struct object *obj = revs->pending.objects[i].item; - if (!(obj->flags & UNINTERESTING)) - continue; - obj = deref_tag(revs->repo, obj, NULL, 0); - if (obj->type != OBJ_COMMIT) - die("Non commit %s?", revs->pending.objects[i].name); - if (found) - die("More than one commit to dig up from, %s and %s?", - revs->pending.objects[i].name, name); - found = (struct commit *) obj; - name = revs->pending.objects[i].name; - } - - if (!name) - found = dwim_reverse_initial(revs, &name); - if (!name) - die("No commit to dig up from?"); - - if (name_p) - *name_p = xstrdup(name); - return found; -} - -void init_scoreboard(struct blame_scoreboard *sb) -{ - memset(sb, 0, sizeof(struct blame_scoreboard)); - sb->move_score = BLAME_DEFAULT_MOVE_SCORE; - sb->copy_score = BLAME_DEFAULT_COPY_SCORE; -} - -void setup_scoreboard(struct blame_scoreboard *sb, - const char *path, - struct blame_origin **orig) -{ - const char *final_commit_name = NULL; - struct blame_origin *o; - struct commit *final_commit = NULL; - enum object_type type; - - init_blame_suspects(&blame_suspects); - - if (sb->reverse && sb->contents_from) - die(_("--contents and --reverse do not blend well.")); - - if (!sb->repo) - BUG("repo is NULL"); - - if (!sb->reverse) { - sb->final = find_single_final(sb->revs, &final_commit_name); - sb->commits.compare = compare_commits_by_commit_date; - } else { - sb->final = find_single_initial(sb->revs, &final_commit_name); - sb->commits.compare = compare_commits_by_reverse_commit_date; - } - - if (sb->final && sb->contents_from) - die(_("cannot use --contents with final commit object name")); - - if (sb->reverse && sb->revs->first_parent_only) - sb->revs->children.name = NULL; - - if (!sb->final) { - /* - * "--not A B -- path" without anything positive; - * do not default to HEAD, but use the working tree - * or "--contents". - */ - setup_work_tree(); - sb->final = fake_working_tree_commit(sb->repo, - &sb->revs->diffopt, - path, sb->contents_from); - add_pending_object(sb->revs, &(sb->final->object), ":"); - } - - if (sb->reverse && sb->revs->first_parent_only) { - final_commit = find_single_final(sb->revs, NULL); - if (!final_commit) - die(_("--reverse and --first-parent together require specified latest commit")); - } - - /* - * If we have bottom, this will mark the ancestors of the - * bottom commits we would reach while traversing as - * uninteresting. - */ - if (prepare_revision_walk(sb->revs)) - die(_("revision walk setup failed")); - - if (sb->reverse && sb->revs->first_parent_only) { - struct commit *c = final_commit; - - sb->revs->children.name = "children"; - while (c->parents && - !oideq(&c->object.oid, &sb->final->object.oid)) { - struct commit_list *l = xcalloc(1, sizeof(*l)); - - l->item = c; - if (add_decoration(&sb->revs->children, - &c->parents->item->object, l)) - BUG("not unique item in first-parent chain"); - c = c->parents->item; - } - - if (!oideq(&c->object.oid, &sb->final->object.oid)) - die(_("--reverse --first-parent together require range along first-parent chain")); - } - - if (is_null_oid(&sb->final->object.oid)) { - o = get_blame_suspects(sb->final); - sb->final_buf = xmemdupz(o->file.ptr, o->file.size); - sb->final_buf_size = o->file.size; - } - else { - o = get_origin(sb->final, path); - if (fill_blob_sha1_and_mode(sb->repo, o)) - die(_("no such path %s in %s"), path, final_commit_name); - - if (sb->revs->diffopt.flags.allow_textconv && - textconv_object(sb->repo, path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf, - &sb->final_buf_size)) - ; - else - sb->final_buf = read_object_file(&o->blob_oid, &type, - &sb->final_buf_size); - - if (!sb->final_buf) - die(_("cannot read blob %s for path %s"), - oid_to_hex(&o->blob_oid), - path); - } - sb->num_read_blob++; - prepare_lines(sb); - - if (orig) - *orig = o; - - free((char *)final_commit_name); -} - - - -struct blame_entry *blame_entry_prepend(struct blame_entry *head, - long start, long end, - struct blame_origin *o) -{ - struct blame_entry *new_head = xcalloc(1, sizeof(struct blame_entry)); - new_head->lno = start; - new_head->num_lines = end - start; - new_head->suspect = o; - new_head->s_lno = start; - new_head->next = head; - blame_origin_incref(o); - return new_head; -} |