diff options
| -rwxr-xr-x | t/t1012-read-tree-df.sh | 4 | ||||
| -rwxr-xr-x | t/t6035-merge-dir-to-symlink.sh | 2 | ||||
| -rw-r--r-- | tree-walk.c | 277 |
3 files changed, 237 insertions, 46 deletions
diff --git a/t/t1012-read-tree-df.sh b/t/t1012-read-tree-df.sh index a961e2ae3..f1e650ac3 100755 --- a/t/t1012-read-tree-df.sh +++ b/t/t1012-read-tree-df.sh @@ -76,7 +76,7 @@ test_expect_failure '3-way (2)' ' EOF ' -test_expect_success '3-way (3)' ' +test_expect_failure '3-way (3)' ' settree A-010 && git read-tree -m -u O-010 A-010 B-010 && checkindex <<-EOF @@ -90,7 +90,7 @@ test_expect_success '3-way (3)' ' EOF ' -test_expect_success '2-way (1)' ' +test_expect_failure '2-way (1)' ' settree O-020 && git read-tree -m -u O-020 A-020 && checkindex <<-EOF diff --git a/t/t6035-merge-dir-to-symlink.sh b/t/t6035-merge-dir-to-symlink.sh index 5b96fb0b3..b9a280e35 100755 --- a/t/t6035-merge-dir-to-symlink.sh +++ b/t/t6035-merge-dir-to-symlink.sh @@ -48,7 +48,7 @@ test_expect_success 'setup for merge test' ' git tag baseline ' -test_expect_success 'do not lose a/b-2/c/d in merge (resolve)' ' +test_expect_failure 'do not lose a/b-2/c/d in merge (resolve)' ' git reset --hard && git checkout baseline^0 && git merge -s resolve master && diff --git a/tree-walk.c b/tree-walk.c index 02e2aed77..08796c232 100644 --- a/tree-walk.c +++ b/tree-walk.c @@ -60,13 +60,6 @@ void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1) return buf; } -static int entry_compare(struct name_entry *a, struct name_entry *b) -{ - return df_name_compare( - a->path, tree_entry_len(a->path, a->sha1), a->mode, - b->path, tree_entry_len(b->path, b->sha1), b->mode); -} - static void entry_clear(struct name_entry *a) { memset(a, 0, sizeof(*a)); @@ -138,66 +131,264 @@ char *make_traverse_path(char *path, const struct traverse_info *info, const str return path; } +struct tree_desc_skip { + struct tree_desc_skip *prev; + const void *ptr; +}; + +struct tree_desc_x { + struct tree_desc d; + struct tree_desc_skip *skip; +}; + +static int name_compare(const char *a, int a_len, + const char *b, int b_len) +{ + int len = (a_len < b_len) ? a_len : b_len; + int cmp = memcmp(a, b, len); + if (cmp) + return cmp; + return (a_len - b_len); +} + +static int check_entry_match(const char *a, int a_len, const char *b, int b_len) +{ + /* + * The caller wants to pick *a* from a tree or nothing. + * We are looking at *b* in a tree. + * + * (0) If a and b are the same name, we are trivially happy. + * + * There are three possibilities where *a* could be hiding + * behind *b*. + * + * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no + * matter what. + * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree; + * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree. + * + * Otherwise we know *a* won't appear in the tree without + * scanning further. + */ + + int cmp = name_compare(a, a_len, b, b_len); + + /* Most common case first -- reading sync'd trees */ + if (!cmp) + return cmp; + + if (0 < cmp) { + /* a comes after b; it does not matter if it is case (3) + if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/') + return 1; + */ + return 1; /* keep looking */ + } + + /* b comes after a; are we looking at case (2)? */ + if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/') + return 1; /* keep looking */ + + return -1; /* a cannot appear in the tree */ +} + +/* + * From the extended tree_desc, extract the first name entry, while + * paying attention to the candidate "first" name. Most importantly, + * when looking for an entry, if there are entries that sorts earlier + * in the tree object representation than that name, skip them and + * process the named entry first. We will remember that we haven't + * processed the first entry yet, and in the later call skip the + * entry we processed early when update_extended_entry() is called. + * + * E.g. if the underlying tree object has these entries: + * + * blob "t-1" + * blob "t-2" + * tree "t" + * blob "t=1" + * + * and the "first" asks for "t", remember that we still need to + * process "t-1" and "t-2" but extract "t". After processing the + * entry "t" from this call, the caller will let us know by calling + * update_extended_entry() that we can remember "t" has been processed + * already. + */ + +static void extended_entry_extract(struct tree_desc_x *t, + struct name_entry *a, + const char *first, + int first_len) +{ + const char *path; + int len; + struct tree_desc probe; + struct tree_desc_skip *skip; + + /* + * Extract the first entry from the tree_desc, but skip the + * ones that we already returned in earlier rounds. + */ + while (1) { + if (!t->d.size) { + entry_clear(a); + break; /* not found */ + } + entry_extract(&t->d, a); + for (skip = t->skip; skip; skip = skip->prev) + if (a->path == skip->ptr) + break; /* found */ + if (!skip) + break; + /* We have processed this entry already. */ + update_tree_entry(&t->d); + } + + if (!first || !a->path) + return; + + /* + * The caller wants "first" from this tree, or nothing. + */ + path = a->path; + len = tree_entry_len(a->path, a->sha1); + switch (check_entry_match(first, first_len, path, len)) { + case -1: + entry_clear(a); + case 0: + return; + default: + break; + } + + /* + * We need to look-ahead -- we suspect that a subtree whose + * name is "first" may be hiding behind the current entry "path". + */ + probe = t->d; + while (probe.size) { + entry_extract(&probe, a); + path = a->path; + len = tree_entry_len(a->path, a->sha1); + switch (check_entry_match(first, first_len, path, len)) { + case -1: + entry_clear(a); + case 0: + return; + default: + update_tree_entry(&probe); + break; + } + /* keep looking */ + } + entry_clear(a); +} + +static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a) +{ + if (t->d.entry.path == a->path) { + update_tree_entry(&t->d); + } else { + /* we have returned this entry early */ + struct tree_desc_skip *skip = xmalloc(sizeof(*skip)); + skip->ptr = a->path; + skip->prev = t->skip; + t->skip = skip; + } +} + +static void free_extended_entry(struct tree_desc_x *t) +{ + struct tree_desc_skip *p, *s; + + for (s = t->skip; s; s = p) { + p = s->prev; + free(s); + } +} + int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info) { int ret = 0; struct name_entry *entry = xmalloc(n*sizeof(*entry)); + int i; + struct tree_desc_x *tx = xcalloc(n, sizeof(*tx)); + + for (i = 0; i < n; i++) + tx[i].d = t[i]; for (;;) { - unsigned long mask = 0; - unsigned long dirmask = 0; - int i, last; + unsigned long mask, dirmask; + const char *first = NULL; + int first_len = 0; + struct name_entry *e; + int len; - last = -1; for (i = 0; i < n; i++) { - if (!t[i].size) + e = entry + i; + extended_entry_extract(tx + i, e, NULL, 0); + } + + /* + * A tree may have "t-2" at the current location even + * though it may have "t" that is a subtree behind it, + * and another tree may return "t". We want to grab + * all "t" from all trees to match in such a case. + */ + for (i = 0; i < n; i++) { + e = entry + i; + if (!e->path) continue; - entry_extract(t+i, entry+i); - if (last >= 0) { - int cmp = entry_compare(entry+i, entry+last); - - /* - * Is the new name bigger than the old one? - * Ignore it - */ - if (cmp > 0) + len = tree_entry_len(e->path, e->sha1); + if (!first) { + first = e->path; + first_len = len; + continue; + } + if (name_compare(e->path, len, first, first_len) < 0) { + first = e->path; + first_len = len; + } + } + + if (first) { + for (i = 0; i < n; i++) { + e = entry + i; + extended_entry_extract(tx + i, e, first, first_len); + /* Cull the ones that are not the earliest */ + if (!e->path) continue; - /* - * Is the new name smaller than the old one? - * Ignore all old ones - */ - if (cmp < 0) - mask = 0; + len = tree_entry_len(e->path, e->sha1); + if (name_compare(e->path, len, first, first_len)) + entry_clear(e); } + } + + /* Now we have in entry[i] the earliest name from the trees */ + mask = 0; + dirmask = 0; + for (i = 0; i < n; i++) { + if (!entry[i].path) + continue; mask |= 1ul << i; if (S_ISDIR(entry[i].mode)) dirmask |= 1ul << i; - last = i; } if (!mask) break; - dirmask &= mask; - - /* - * Clear all the unused name-entries. - */ - for (i = 0; i < n; i++) { - if (mask & (1ul << i)) - continue; - entry_clear(entry + i); - } ret = info->fn(n, mask, dirmask, entry, info); if (ret < 0) break; - if (ret) - mask &= ret; + mask &= ret; ret = 0; - for (i = 0; i < n; i++) { + for (i = 0; i < n; i++) if (mask & (1ul << i)) - update_tree_entry(t + i); - } + update_extended_entry(tx + i, entry + i); } free(entry); + for (i = 0; i < n; i++) + free_extended_entry(tx + i); + free(tx); return ret; } |