diff options
Diffstat (limited to 'merge-tree.c')
| -rw-r--r-- | merge-tree.c | 272 |
1 files changed, 0 insertions, 272 deletions
diff --git a/merge-tree.c b/merge-tree.c deleted file mode 100644 index 768d83a7c2..0000000000 --- a/merge-tree.c +++ /dev/null @@ -1,272 +0,0 @@ -#include "cache.h" -#include "diff.h" - -static const char merge_tree_usage[] = "git-merge-tree <base-tree> <branch1> <branch2>"; -static int resolve_directories = 1; - -static void merge_trees(struct tree_desc t[3], const char *base); - -static void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1) -{ - unsigned long size = 0; - void *buf = NULL; - - if (sha1) { - buf = read_object_with_reference(sha1, "tree", &size, NULL); - if (!buf) - die("unable to read tree %s", sha1_to_hex(sha1)); - } - desc->size = size; - desc->buf = buf; - return buf; -} - -struct name_entry { - const unsigned char *sha1; - const char *path; - unsigned int mode; - int pathlen; -}; - -static void entry_clear(struct name_entry *a) -{ - memset(a, 0, sizeof(*a)); -} - -static int entry_compare(struct name_entry *a, struct name_entry *b) -{ - return base_name_compare( - a->path, a->pathlen, a->mode, - b->path, b->pathlen, b->mode); -} - -static void entry_extract(struct tree_desc *t, struct name_entry *a) -{ - a->sha1 = tree_entry_extract(t, &a->path, &a->mode); - a->pathlen = strlen(a->path); -} - -/* An empty entry never compares same, not even to another empty entry */ -static int same_entry(struct name_entry *a, struct name_entry *b) -{ - return a->sha1 && - b->sha1 && - !memcmp(a->sha1, b->sha1, 20) && - a->mode == b->mode; -} - -static const char *sha1_to_hex_zero(const unsigned char *sha1) -{ - if (sha1) - return sha1_to_hex(sha1); - return "0000000000000000000000000000000000000000"; -} - -static void resolve(const char *base, struct name_entry *branch1, struct name_entry *result) -{ - char branch1_sha1[50]; - - /* If it's already branch1, don't bother showing it */ - if (!branch1) - return; - memcpy(branch1_sha1, sha1_to_hex_zero(branch1->sha1), 41); - - printf("0 %06o->%06o %s->%s %s%s\n", - branch1->mode, result->mode, - branch1_sha1, sha1_to_hex_zero(result->sha1), - base, result->path); -} - -static int unresolved_directory(const char *base, struct name_entry n[3]) -{ - int baselen; - char *newbase; - struct name_entry *p; - struct tree_desc t[3]; - void *buf0, *buf1, *buf2; - - if (!resolve_directories) - return 0; - p = n; - if (!p->mode) { - p++; - if (!p->mode) - p++; - } - if (!S_ISDIR(p->mode)) - return 0; - baselen = strlen(base); - newbase = xmalloc(baselen + p->pathlen + 2); - memcpy(newbase, base, baselen); - memcpy(newbase + baselen, p->path, p->pathlen); - memcpy(newbase + baselen + p->pathlen, "/", 2); - - buf0 = fill_tree_descriptor(t+0, n[0].sha1); - buf1 = fill_tree_descriptor(t+1, n[1].sha1); - buf2 = fill_tree_descriptor(t+2, n[2].sha1); - merge_trees(t, newbase); - - free(buf0); - free(buf1); - free(buf2); - free(newbase); - return 1; -} - -static void unresolved(const char *base, struct name_entry n[3]) -{ - if (unresolved_directory(base, n)) - return; - if (n[0].sha1) - printf("1 %06o %s %s%s\n", n[0].mode, sha1_to_hex(n[0].sha1), base, n[0].path); - if (n[1].sha1) - printf("2 %06o %s %s%s\n", n[1].mode, sha1_to_hex(n[1].sha1), base, n[1].path); - if (n[2].sha1) - printf("3 %06o %s %s%s\n", n[2].mode, sha1_to_hex(n[2].sha1), base, n[2].path); -} - -typedef void (*traverse_callback_t)(int n, unsigned long mask, struct name_entry *entry, const char *base); - -static void traverse_trees(int n, struct tree_desc *t, const char *base, traverse_callback_t callback) -{ - struct name_entry *entry = xmalloc(n*sizeof(*entry)); - - for (;;) { - struct name_entry entry[3]; - unsigned long mask = 0; - int i, last; - - last = -1; - for (i = 0; i < n; i++) { - if (!t[i].size) - 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) - continue; - /* - * Is the new name smaller than the old one? - * Ignore all old ones - */ - if (cmp < 0) - mask = 0; - } - mask |= 1ul << i; - last = i; - } - if (!mask) - break; - - /* - * Update the tree entries we've walked, and clear - * all the unused name-entries. - */ - for (i = 0; i < n; i++) { - if (mask & (1ul << i)) { - update_tree_entry(t+i); - continue; - } - entry_clear(entry + i); - } - callback(n, mask, entry, base); - } - free(entry); -} - -/* - * Merge two trees together (t[1] and t[2]), using a common base (t[0]) - * as the origin. - * - * This walks the (sorted) trees in lock-step, checking every possible - * name. Note that directories automatically sort differently from other - * files (see "base_name_compare"), so you'll never see file/directory - * conflicts, because they won't ever compare the same. - * - * IOW, if a directory changes to a filename, it will automatically be - * seen as the directory going away, and the filename being created. - * - * Think of this as a three-way diff. - * - * The output will be either: - * - successful merge - * "0 mode sha1 filename" - * NOTE NOTE NOTE! FIXME! We really really need to walk the index - * in parallel with this too! - * - * - conflict: - * "1 mode sha1 filename" - * "2 mode sha1 filename" - * "3 mode sha1 filename" - * where not all of the 1/2/3 lines may exist, of course. - * - * The successful merge rules are the same as for the three-way merge - * in git-read-tree. - */ -static void threeway_callback(int n, unsigned long mask, struct name_entry *entry, const char *base) -{ - /* Same in both? */ - if (same_entry(entry+1, entry+2)) { - if (entry[0].sha1) { - resolve(base, NULL, entry+1); - return; - } - } - - if (same_entry(entry+0, entry+1)) { - if (entry[2].sha1 && !S_ISDIR(entry[2].mode)) { - resolve(base, entry+1, entry+2); - return; - } - } - - if (same_entry(entry+0, entry+2)) { - if (entry[1].sha1 && !S_ISDIR(entry[1].mode)) { - resolve(base, NULL, entry+1); - return; - } - } - - unresolved(base, entry); -} - -static void merge_trees(struct tree_desc t[3], const char *base) -{ - traverse_trees(3, t, base, threeway_callback); -} - -static void *get_tree_descriptor(struct tree_desc *desc, const char *rev) -{ - unsigned char sha1[20]; - void *buf; - - if (get_sha1(rev, sha1) < 0) - die("unknown rev %s", rev); - buf = fill_tree_descriptor(desc, sha1); - if (!buf) - die("%s is not a tree", rev); - return buf; -} - -int main(int argc, char **argv) -{ - struct tree_desc t[3]; - void *buf1, *buf2, *buf3; - - if (argc < 4) - usage(merge_tree_usage); - - buf1 = get_tree_descriptor(t+0, argv[1]); - buf2 = get_tree_descriptor(t+1, argv[2]); - buf3 = get_tree_descriptor(t+2, argv[3]); - merge_trees(t, ""); - free(buf1); - free(buf2); - free(buf3); - return 0; -} |