branch: add test for -m renaming multiple config sections
[git.git] / notes.c
blob542563b280ad305da1452d57653728b9005874e6
1 #include "cache.h"
2 #include "notes.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "utf8.h"
6 #include "strbuf.h"
7 #include "tree-walk.h"
8 #include "string-list.h"
9 #include "refs.h"
12 * Use a non-balancing simple 16-tree structure with struct int_node as
13 * internal nodes, and struct leaf_node as leaf nodes. Each int_node has a
14 * 16-array of pointers to its children.
15 * The bottom 2 bits of each pointer is used to identify the pointer type
16 * - ptr & 3 == 0 - NULL pointer, assert(ptr == NULL)
17 * - ptr & 3 == 1 - pointer to next internal node - cast to struct int_node *
18 * - ptr & 3 == 2 - pointer to note entry - cast to struct leaf_node *
19 * - ptr & 3 == 3 - pointer to subtree entry - cast to struct leaf_node *
21 * The root node is a statically allocated struct int_node.
23 struct int_node {
24 void *a[16];
28 * Leaf nodes come in two variants, note entries and subtree entries,
29 * distinguished by the LSb of the leaf node pointer (see above).
30 * As a note entry, the key is the SHA1 of the referenced object, and the
31 * value is the SHA1 of the note object.
32 * As a subtree entry, the key is the prefix SHA1 (w/trailing NULs) of the
33 * referenced object, using the last byte of the key to store the length of
34 * the prefix. The value is the SHA1 of the tree object containing the notes
35 * subtree.
37 struct leaf_node {
38 unsigned char key_sha1[20];
39 unsigned char val_sha1[20];
43 * A notes tree may contain entries that are not notes, and that do not follow
44 * the naming conventions of notes. There are typically none/few of these, but
45 * we still need to keep track of them. Keep a simple linked list sorted alpha-
46 * betically on the non-note path. The list is populated when parsing tree
47 * objects in load_subtree(), and the non-notes are correctly written back into
48 * the tree objects produced by write_notes_tree().
50 struct non_note {
51 struct non_note *next; /* grounded (last->next == NULL) */
52 char *path;
53 unsigned int mode;
54 unsigned char sha1[20];
57 #define PTR_TYPE_NULL 0
58 #define PTR_TYPE_INTERNAL 1
59 #define PTR_TYPE_NOTE 2
60 #define PTR_TYPE_SUBTREE 3
62 #define GET_PTR_TYPE(ptr) ((uintptr_t) (ptr) & 3)
63 #define CLR_PTR_TYPE(ptr) ((void *) ((uintptr_t) (ptr) & ~3))
64 #define SET_PTR_TYPE(ptr, type) ((void *) ((uintptr_t) (ptr) | (type)))
66 #define GET_NIBBLE(n, sha1) (((sha1[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f)
68 #define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
69 (memcmp(key_sha1, subtree_sha1, subtree_sha1[19]))
71 struct notes_tree default_notes_tree;
73 static struct string_list display_notes_refs = STRING_LIST_INIT_NODUP;
74 static struct notes_tree **display_notes_trees;
76 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
77 struct int_node *node, unsigned int n);
80 * Search the tree until the appropriate location for the given key is found:
81 * 1. Start at the root node, with n = 0
82 * 2. If a[0] at the current level is a matching subtree entry, unpack that
83 * subtree entry and remove it; restart search at the current level.
84 * 3. Use the nth nibble of the key as an index into a:
85 * - If a[n] is an int_node, recurse from #2 into that node and increment n
86 * - If a matching subtree entry, unpack that subtree entry (and remove it);
87 * restart search at the current level.
88 * - Otherwise, we have found one of the following:
89 * - a subtree entry which does not match the key
90 * - a note entry which may or may not match the key
91 * - an unused leaf node (NULL)
92 * In any case, set *tree and *n, and return pointer to the tree location.
94 static void **note_tree_search(struct notes_tree *t, struct int_node **tree,
95 unsigned char *n, const unsigned char *key_sha1)
97 struct leaf_node *l;
98 unsigned char i;
99 void *p = (*tree)->a[0];
101 if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) {
102 l = (struct leaf_node *) CLR_PTR_TYPE(p);
103 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
104 /* unpack tree and resume search */
105 (*tree)->a[0] = NULL;
106 load_subtree(t, l, *tree, *n);
107 free(l);
108 return note_tree_search(t, tree, n, key_sha1);
112 i = GET_NIBBLE(*n, key_sha1);
113 p = (*tree)->a[i];
114 switch (GET_PTR_TYPE(p)) {
115 case PTR_TYPE_INTERNAL:
116 *tree = CLR_PTR_TYPE(p);
117 (*n)++;
118 return note_tree_search(t, tree, n, key_sha1);
119 case PTR_TYPE_SUBTREE:
120 l = (struct leaf_node *) CLR_PTR_TYPE(p);
121 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
122 /* unpack tree and resume search */
123 (*tree)->a[i] = NULL;
124 load_subtree(t, l, *tree, *n);
125 free(l);
126 return note_tree_search(t, tree, n, key_sha1);
128 /* fall through */
129 default:
130 return &((*tree)->a[i]);
135 * To find a leaf_node:
136 * Search to the tree location appropriate for the given key:
137 * If a note entry with matching key, return the note entry, else return NULL.
139 static struct leaf_node *note_tree_find(struct notes_tree *t,
140 struct int_node *tree, unsigned char n,
141 const unsigned char *key_sha1)
143 void **p = note_tree_search(t, &tree, &n, key_sha1);
144 if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) {
145 struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p);
146 if (!hashcmp(key_sha1, l->key_sha1))
147 return l;
149 return NULL;
153 * How to consolidate an int_node:
154 * If there are > 1 non-NULL entries, give up and return non-zero.
155 * Otherwise replace the int_node at the given index in the given parent node
156 * with the only NOTE entry (or a NULL entry if no entries) from the given
157 * tree, and return 0.
159 static int note_tree_consolidate(struct int_node *tree,
160 struct int_node *parent, unsigned char index)
162 unsigned int i;
163 void *p = NULL;
165 assert(tree && parent);
166 assert(CLR_PTR_TYPE(parent->a[index]) == tree);
168 for (i = 0; i < 16; i++) {
169 if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) {
170 if (p) /* more than one entry */
171 return -2;
172 p = tree->a[i];
176 if (p && (GET_PTR_TYPE(p) != PTR_TYPE_NOTE))
177 return -2;
178 /* replace tree with p in parent[index] */
179 parent->a[index] = p;
180 free(tree);
181 return 0;
185 * To remove a leaf_node:
186 * Search to the tree location appropriate for the given leaf_node's key:
187 * - If location does not hold a matching entry, abort and do nothing.
188 * - Copy the matching entry's value into the given entry.
189 * - Replace the matching leaf_node with a NULL entry (and free the leaf_node).
190 * - Consolidate int_nodes repeatedly, while walking up the tree towards root.
192 static void note_tree_remove(struct notes_tree *t,
193 struct int_node *tree, unsigned char n,
194 struct leaf_node *entry)
196 struct leaf_node *l;
197 struct int_node *parent_stack[20];
198 unsigned char i, j;
199 void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
201 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
202 if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
203 return; /* type mismatch, nothing to remove */
204 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
205 if (hashcmp(l->key_sha1, entry->key_sha1))
206 return; /* key mismatch, nothing to remove */
208 /* we have found a matching entry */
209 hashcpy(entry->val_sha1, l->val_sha1);
210 free(l);
211 *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
213 /* consolidate this tree level, and parent levels, if possible */
214 if (!n)
215 return; /* cannot consolidate top level */
216 /* first, build stack of ancestors between root and current node */
217 parent_stack[0] = t->root;
218 for (i = 0; i < n; i++) {
219 j = GET_NIBBLE(i, entry->key_sha1);
220 parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]);
222 assert(i == n && parent_stack[i] == tree);
223 /* next, unwind stack until note_tree_consolidate() is done */
224 while (i > 0 &&
225 !note_tree_consolidate(parent_stack[i], parent_stack[i - 1],
226 GET_NIBBLE(i - 1, entry->key_sha1)))
227 i--;
231 * To insert a leaf_node:
232 * Search to the tree location appropriate for the given leaf_node's key:
233 * - If location is unused (NULL), store the tweaked pointer directly there
234 * - If location holds a note entry that matches the note-to-be-inserted, then
235 * combine the two notes (by calling the given combine_notes function).
236 * - If location holds a note entry that matches the subtree-to-be-inserted,
237 * then unpack the subtree-to-be-inserted into the location.
238 * - If location holds a matching subtree entry, unpack the subtree at that
239 * location, and restart the insert operation from that level.
240 * - Else, create a new int_node, holding both the node-at-location and the
241 * node-to-be-inserted, and store the new int_node into the location.
243 static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
244 unsigned char n, struct leaf_node *entry, unsigned char type,
245 combine_notes_fn combine_notes)
247 struct int_node *new_node;
248 struct leaf_node *l;
249 void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
250 int ret = 0;
252 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
253 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
254 switch (GET_PTR_TYPE(*p)) {
255 case PTR_TYPE_NULL:
256 assert(!*p);
257 if (is_null_sha1(entry->val_sha1))
258 free(entry);
259 else
260 *p = SET_PTR_TYPE(entry, type);
261 return 0;
262 case PTR_TYPE_NOTE:
263 switch (type) {
264 case PTR_TYPE_NOTE:
265 if (!hashcmp(l->key_sha1, entry->key_sha1)) {
266 /* skip concatenation if l == entry */
267 if (!hashcmp(l->val_sha1, entry->val_sha1))
268 return 0;
270 ret = combine_notes(l->val_sha1,
271 entry->val_sha1);
272 if (!ret && is_null_sha1(l->val_sha1))
273 note_tree_remove(t, tree, n, entry);
274 free(entry);
275 return ret;
277 break;
278 case PTR_TYPE_SUBTREE:
279 if (!SUBTREE_SHA1_PREFIXCMP(l->key_sha1,
280 entry->key_sha1)) {
281 /* unpack 'entry' */
282 load_subtree(t, entry, tree, n);
283 free(entry);
284 return 0;
286 break;
288 break;
289 case PTR_TYPE_SUBTREE:
290 if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) {
291 /* unpack 'l' and restart insert */
292 *p = NULL;
293 load_subtree(t, l, tree, n);
294 free(l);
295 return note_tree_insert(t, tree, n, entry, type,
296 combine_notes);
298 break;
301 /* non-matching leaf_node */
302 assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
303 GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
304 if (is_null_sha1(entry->val_sha1)) { /* skip insertion of empty note */
305 free(entry);
306 return 0;
308 new_node = (struct int_node *) xcalloc(1, sizeof(struct int_node));
309 ret = note_tree_insert(t, new_node, n + 1, l, GET_PTR_TYPE(*p),
310 combine_notes);
311 if (ret)
312 return ret;
313 *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
314 return note_tree_insert(t, new_node, n + 1, entry, type, combine_notes);
317 /* Free the entire notes data contained in the given tree */
318 static void note_tree_free(struct int_node *tree)
320 unsigned int i;
321 for (i = 0; i < 16; i++) {
322 void *p = tree->a[i];
323 switch (GET_PTR_TYPE(p)) {
324 case PTR_TYPE_INTERNAL:
325 note_tree_free(CLR_PTR_TYPE(p));
326 /* fall through */
327 case PTR_TYPE_NOTE:
328 case PTR_TYPE_SUBTREE:
329 free(CLR_PTR_TYPE(p));
335 * Convert a partial SHA1 hex string to the corresponding partial SHA1 value.
336 * - hex - Partial SHA1 segment in ASCII hex format
337 * - hex_len - Length of above segment. Must be multiple of 2 between 0 and 40
338 * - sha1 - Partial SHA1 value is written here
339 * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20
340 * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format)).
341 * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2).
342 * Pads sha1 with NULs up to sha1_len (not included in returned length).
344 static int get_sha1_hex_segment(const char *hex, unsigned int hex_len,
345 unsigned char *sha1, unsigned int sha1_len)
347 unsigned int i, len = hex_len >> 1;
348 if (hex_len % 2 != 0 || len > sha1_len)
349 return -1;
350 for (i = 0; i < len; i++) {
351 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
352 if (val & ~0xff)
353 return -1;
354 *sha1++ = val;
355 hex += 2;
357 for (; i < sha1_len; i++)
358 *sha1++ = 0;
359 return len;
362 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
364 return strcmp(a->path, b->path);
367 /* note: takes ownership of path string */
368 static void add_non_note(struct notes_tree *t, char *path,
369 unsigned int mode, const unsigned char *sha1)
371 struct non_note *p = t->prev_non_note, *n;
372 n = (struct non_note *) xmalloc(sizeof(struct non_note));
373 n->next = NULL;
374 n->path = path;
375 n->mode = mode;
376 hashcpy(n->sha1, sha1);
377 t->prev_non_note = n;
379 if (!t->first_non_note) {
380 t->first_non_note = n;
381 return;
384 if (non_note_cmp(p, n) < 0)
385 ; /* do nothing */
386 else if (non_note_cmp(t->first_non_note, n) <= 0)
387 p = t->first_non_note;
388 else {
389 /* n sorts before t->first_non_note */
390 n->next = t->first_non_note;
391 t->first_non_note = n;
392 return;
395 /* n sorts equal or after p */
396 while (p->next && non_note_cmp(p->next, n) <= 0)
397 p = p->next;
399 if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
400 assert(strcmp(p->path, n->path) == 0);
401 p->mode = n->mode;
402 hashcpy(p->sha1, n->sha1);
403 free(n);
404 t->prev_non_note = p;
405 return;
408 /* n sorts between p and p->next */
409 n->next = p->next;
410 p->next = n;
413 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
414 struct int_node *node, unsigned int n)
416 unsigned char object_sha1[20];
417 unsigned int prefix_len;
418 void *buf;
419 struct tree_desc desc;
420 struct name_entry entry;
421 int len, path_len;
422 unsigned char type;
423 struct leaf_node *l;
425 buf = fill_tree_descriptor(&desc, subtree->val_sha1);
426 if (!buf)
427 die("Could not read %s for notes-index",
428 sha1_to_hex(subtree->val_sha1));
430 prefix_len = subtree->key_sha1[19];
431 assert(prefix_len * 2 >= n);
432 memcpy(object_sha1, subtree->key_sha1, prefix_len);
433 while (tree_entry(&desc, &entry)) {
434 path_len = strlen(entry.path);
435 len = get_sha1_hex_segment(entry.path, path_len,
436 object_sha1 + prefix_len, 20 - prefix_len);
437 if (len < 0)
438 goto handle_non_note; /* entry.path is not a SHA1 */
439 len += prefix_len;
442 * If object SHA1 is complete (len == 20), assume note object
443 * If object SHA1 is incomplete (len < 20), and current
444 * component consists of 2 hex chars, assume note subtree
446 if (len <= 20) {
447 type = PTR_TYPE_NOTE;
448 l = (struct leaf_node *)
449 xcalloc(1, sizeof(struct leaf_node));
450 hashcpy(l->key_sha1, object_sha1);
451 hashcpy(l->val_sha1, entry.oid->hash);
452 if (len < 20) {
453 if (!S_ISDIR(entry.mode) || path_len != 2)
454 goto handle_non_note; /* not subtree */
455 l->key_sha1[19] = (unsigned char) len;
456 type = PTR_TYPE_SUBTREE;
458 if (note_tree_insert(t, node, n, l, type,
459 combine_notes_concatenate))
460 die("Failed to load %s %s into notes tree "
461 "from %s",
462 type == PTR_TYPE_NOTE ? "note" : "subtree",
463 sha1_to_hex(l->key_sha1), t->ref);
465 continue;
467 handle_non_note:
469 * Determine full path for this non-note entry:
470 * The filename is already found in entry.path, but the
471 * directory part of the path must be deduced from the subtree
472 * containing this entry. We assume here that the overall notes
473 * tree follows a strict byte-based progressive fanout
474 * structure (i.e. using 2/38, 2/2/36, etc. fanouts, and not
475 * e.g. 4/36 fanout). This means that if a non-note is found at
476 * path "dead/beef", the following code will register it as
477 * being found on "de/ad/beef".
478 * On the other hand, if you use such non-obvious non-note
479 * paths in the middle of a notes tree, you deserve what's
480 * coming to you ;). Note that for non-notes that are not
481 * SHA1-like at the top level, there will be no problems.
483 * To conclude, it is strongly advised to make sure non-notes
484 * have at least one non-hex character in the top-level path
485 * component.
488 struct strbuf non_note_path = STRBUF_INIT;
489 const char *q = sha1_to_hex(subtree->key_sha1);
490 int i;
491 for (i = 0; i < prefix_len; i++) {
492 strbuf_addch(&non_note_path, *q++);
493 strbuf_addch(&non_note_path, *q++);
494 strbuf_addch(&non_note_path, '/');
496 strbuf_addstr(&non_note_path, entry.path);
497 add_non_note(t, strbuf_detach(&non_note_path, NULL),
498 entry.mode, entry.oid->hash);
501 free(buf);
505 * Determine optimal on-disk fanout for this part of the notes tree
507 * Given a (sub)tree and the level in the internal tree structure, determine
508 * whether or not the given existing fanout should be expanded for this
509 * (sub)tree.
511 * Values of the 'fanout' variable:
512 * - 0: No fanout (all notes are stored directly in the root notes tree)
513 * - 1: 2/38 fanout
514 * - 2: 2/2/36 fanout
515 * - 3: 2/2/2/34 fanout
516 * etc.
518 static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
519 unsigned char fanout)
522 * The following is a simple heuristic that works well in practice:
523 * For each even-numbered 16-tree level (remember that each on-disk
524 * fanout level corresponds to _two_ 16-tree levels), peek at all 16
525 * entries at that tree level. If all of them are either int_nodes or
526 * subtree entries, then there are likely plenty of notes below this
527 * level, so we return an incremented fanout.
529 unsigned int i;
530 if ((n % 2) || (n > 2 * fanout))
531 return fanout;
532 for (i = 0; i < 16; i++) {
533 switch (GET_PTR_TYPE(tree->a[i])) {
534 case PTR_TYPE_SUBTREE:
535 case PTR_TYPE_INTERNAL:
536 continue;
537 default:
538 return fanout;
541 return fanout + 1;
544 /* hex SHA1 + 19 * '/' + NUL */
545 #define FANOUT_PATH_MAX 40 + 19 + 1
547 static void construct_path_with_fanout(const unsigned char *sha1,
548 unsigned char fanout, char *path)
550 unsigned int i = 0, j = 0;
551 const char *hex_sha1 = sha1_to_hex(sha1);
552 assert(fanout < 20);
553 while (fanout) {
554 path[i++] = hex_sha1[j++];
555 path[i++] = hex_sha1[j++];
556 path[i++] = '/';
557 fanout--;
559 xsnprintf(path + i, FANOUT_PATH_MAX - i, "%s", hex_sha1 + j);
562 static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
563 unsigned char n, unsigned char fanout, int flags,
564 each_note_fn fn, void *cb_data)
566 unsigned int i;
567 void *p;
568 int ret = 0;
569 struct leaf_node *l;
570 static char path[FANOUT_PATH_MAX];
572 fanout = determine_fanout(tree, n, fanout);
573 for (i = 0; i < 16; i++) {
574 redo:
575 p = tree->a[i];
576 switch (GET_PTR_TYPE(p)) {
577 case PTR_TYPE_INTERNAL:
578 /* recurse into int_node */
579 ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
580 fanout, flags, fn, cb_data);
581 break;
582 case PTR_TYPE_SUBTREE:
583 l = (struct leaf_node *) CLR_PTR_TYPE(p);
585 * Subtree entries in the note tree represent parts of
586 * the note tree that have not yet been explored. There
587 * is a direct relationship between subtree entries at
588 * level 'n' in the tree, and the 'fanout' variable:
589 * Subtree entries at level 'n <= 2 * fanout' should be
590 * preserved, since they correspond exactly to a fanout
591 * directory in the on-disk structure. However, subtree
592 * entries at level 'n > 2 * fanout' should NOT be
593 * preserved, but rather consolidated into the above
594 * notes tree level. We achieve this by unconditionally
595 * unpacking subtree entries that exist below the
596 * threshold level at 'n = 2 * fanout'.
598 if (n <= 2 * fanout &&
599 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
600 /* invoke callback with subtree */
601 unsigned int path_len =
602 l->key_sha1[19] * 2 + fanout;
603 assert(path_len < FANOUT_PATH_MAX - 1);
604 construct_path_with_fanout(l->key_sha1, fanout,
605 path);
606 /* Create trailing slash, if needed */
607 if (path[path_len - 1] != '/')
608 path[path_len++] = '/';
609 path[path_len] = '\0';
610 ret = fn(l->key_sha1, l->val_sha1, path,
611 cb_data);
613 if (n > fanout * 2 ||
614 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
615 /* unpack subtree and resume traversal */
616 tree->a[i] = NULL;
617 load_subtree(t, l, tree, n);
618 free(l);
619 goto redo;
621 break;
622 case PTR_TYPE_NOTE:
623 l = (struct leaf_node *) CLR_PTR_TYPE(p);
624 construct_path_with_fanout(l->key_sha1, fanout, path);
625 ret = fn(l->key_sha1, l->val_sha1, path, cb_data);
626 break;
628 if (ret)
629 return ret;
631 return 0;
634 struct tree_write_stack {
635 struct tree_write_stack *next;
636 struct strbuf buf;
637 char path[2]; /* path to subtree in next, if any */
640 static inline int matches_tree_write_stack(struct tree_write_stack *tws,
641 const char *full_path)
643 return full_path[0] == tws->path[0] &&
644 full_path[1] == tws->path[1] &&
645 full_path[2] == '/';
648 static void write_tree_entry(struct strbuf *buf, unsigned int mode,
649 const char *path, unsigned int path_len, const
650 unsigned char *sha1)
652 strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
653 strbuf_add(buf, sha1, 20);
656 static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
657 const char *path)
659 struct tree_write_stack *n;
660 assert(!tws->next);
661 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
662 n = (struct tree_write_stack *)
663 xmalloc(sizeof(struct tree_write_stack));
664 n->next = NULL;
665 strbuf_init(&n->buf, 256 * (32 + 40)); /* assume 256 entries per tree */
666 n->path[0] = n->path[1] = '\0';
667 tws->next = n;
668 tws->path[0] = path[0];
669 tws->path[1] = path[1];
672 static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
674 int ret;
675 struct tree_write_stack *n = tws->next;
676 unsigned char s[20];
677 if (n) {
678 ret = tree_write_stack_finish_subtree(n);
679 if (ret)
680 return ret;
681 ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s);
682 if (ret)
683 return ret;
684 strbuf_release(&n->buf);
685 free(n);
686 tws->next = NULL;
687 write_tree_entry(&tws->buf, 040000, tws->path, 2, s);
688 tws->path[0] = tws->path[1] = '\0';
690 return 0;
693 static int write_each_note_helper(struct tree_write_stack *tws,
694 const char *path, unsigned int mode,
695 const unsigned char *sha1)
697 size_t path_len = strlen(path);
698 unsigned int n = 0;
699 int ret;
701 /* Determine common part of tree write stack */
702 while (tws && 3 * n < path_len &&
703 matches_tree_write_stack(tws, path + 3 * n)) {
704 n++;
705 tws = tws->next;
708 /* tws point to last matching tree_write_stack entry */
709 ret = tree_write_stack_finish_subtree(tws);
710 if (ret)
711 return ret;
713 /* Start subtrees needed to satisfy path */
714 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
715 tree_write_stack_init_subtree(tws, path + 3 * n);
716 n++;
717 tws = tws->next;
720 /* There should be no more directory components in the given path */
721 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
723 /* Finally add given entry to the current tree object */
724 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
725 sha1);
727 return 0;
730 struct write_each_note_data {
731 struct tree_write_stack *root;
732 struct non_note *next_non_note;
735 static int write_each_non_note_until(const char *note_path,
736 struct write_each_note_data *d)
738 struct non_note *n = d->next_non_note;
739 int cmp = 0, ret;
740 while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
741 if (note_path && cmp == 0)
742 ; /* do nothing, prefer note to non-note */
743 else {
744 ret = write_each_note_helper(d->root, n->path, n->mode,
745 n->sha1);
746 if (ret)
747 return ret;
749 n = n->next;
751 d->next_non_note = n;
752 return 0;
755 static int write_each_note(const unsigned char *object_sha1,
756 const unsigned char *note_sha1, char *note_path,
757 void *cb_data)
759 struct write_each_note_data *d =
760 (struct write_each_note_data *) cb_data;
761 size_t note_path_len = strlen(note_path);
762 unsigned int mode = 0100644;
764 if (note_path[note_path_len - 1] == '/') {
765 /* subtree entry */
766 note_path_len--;
767 note_path[note_path_len] = '\0';
768 mode = 040000;
770 assert(note_path_len <= 40 + 19);
772 /* Weave non-note entries into note entries */
773 return write_each_non_note_until(note_path, d) ||
774 write_each_note_helper(d->root, note_path, mode, note_sha1);
777 struct note_delete_list {
778 struct note_delete_list *next;
779 const unsigned char *sha1;
782 static int prune_notes_helper(const unsigned char *object_sha1,
783 const unsigned char *note_sha1, char *note_path,
784 void *cb_data)
786 struct note_delete_list **l = (struct note_delete_list **) cb_data;
787 struct note_delete_list *n;
789 if (has_sha1_file(object_sha1))
790 return 0; /* nothing to do for this note */
792 /* failed to find object => prune this note */
793 n = (struct note_delete_list *) xmalloc(sizeof(*n));
794 n->next = *l;
795 n->sha1 = object_sha1;
796 *l = n;
797 return 0;
800 int combine_notes_concatenate(unsigned char *cur_sha1,
801 const unsigned char *new_sha1)
803 char *cur_msg = NULL, *new_msg = NULL, *buf;
804 unsigned long cur_len, new_len, buf_len;
805 enum object_type cur_type, new_type;
806 int ret;
808 /* read in both note blob objects */
809 if (!is_null_sha1(new_sha1))
810 new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
811 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
812 free(new_msg);
813 return 0;
815 if (!is_null_sha1(cur_sha1))
816 cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
817 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
818 free(cur_msg);
819 free(new_msg);
820 hashcpy(cur_sha1, new_sha1);
821 return 0;
824 /* we will separate the notes by two newlines anyway */
825 if (cur_msg[cur_len - 1] == '\n')
826 cur_len--;
828 /* concatenate cur_msg and new_msg into buf */
829 buf_len = cur_len + 2 + new_len;
830 buf = (char *) xmalloc(buf_len);
831 memcpy(buf, cur_msg, cur_len);
832 buf[cur_len] = '\n';
833 buf[cur_len + 1] = '\n';
834 memcpy(buf + cur_len + 2, new_msg, new_len);
835 free(cur_msg);
836 free(new_msg);
838 /* create a new blob object from buf */
839 ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
840 free(buf);
841 return ret;
844 int combine_notes_overwrite(unsigned char *cur_sha1,
845 const unsigned char *new_sha1)
847 hashcpy(cur_sha1, new_sha1);
848 return 0;
851 int combine_notes_ignore(unsigned char *cur_sha1,
852 const unsigned char *new_sha1)
854 return 0;
858 * Add the lines from the named object to list, with trailing
859 * newlines removed.
861 static int string_list_add_note_lines(struct string_list *list,
862 const unsigned char *sha1)
864 char *data;
865 unsigned long len;
866 enum object_type t;
868 if (is_null_sha1(sha1))
869 return 0;
871 /* read_sha1_file NUL-terminates */
872 data = read_sha1_file(sha1, &t, &len);
873 if (t != OBJ_BLOB || !data || !len) {
874 free(data);
875 return t != OBJ_BLOB || !data;
879 * If the last line of the file is EOL-terminated, this will
880 * add an empty string to the list. But it will be removed
881 * later, along with any empty strings that came from empty
882 * lines within the file.
884 string_list_split(list, data, '\n', -1);
885 free(data);
886 return 0;
889 static int string_list_join_lines_helper(struct string_list_item *item,
890 void *cb_data)
892 struct strbuf *buf = cb_data;
893 strbuf_addstr(buf, item->string);
894 strbuf_addch(buf, '\n');
895 return 0;
898 int combine_notes_cat_sort_uniq(unsigned char *cur_sha1,
899 const unsigned char *new_sha1)
901 struct string_list sort_uniq_list = STRING_LIST_INIT_DUP;
902 struct strbuf buf = STRBUF_INIT;
903 int ret = 1;
905 /* read both note blob objects into unique_lines */
906 if (string_list_add_note_lines(&sort_uniq_list, cur_sha1))
907 goto out;
908 if (string_list_add_note_lines(&sort_uniq_list, new_sha1))
909 goto out;
910 string_list_remove_empty_items(&sort_uniq_list, 0);
911 string_list_sort(&sort_uniq_list);
912 string_list_remove_duplicates(&sort_uniq_list, 0);
914 /* create a new blob object from sort_uniq_list */
915 if (for_each_string_list(&sort_uniq_list,
916 string_list_join_lines_helper, &buf))
917 goto out;
919 ret = write_sha1_file(buf.buf, buf.len, blob_type, cur_sha1);
921 out:
922 strbuf_release(&buf);
923 string_list_clear(&sort_uniq_list, 0);
924 return ret;
927 static int string_list_add_one_ref(const char *refname, const struct object_id *oid,
928 int flag, void *cb)
930 struct string_list *refs = cb;
931 if (!unsorted_string_list_has_string(refs, refname))
932 string_list_append(refs, refname);
933 return 0;
937 * The list argument must have strdup_strings set on it.
939 void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
941 assert(list->strdup_strings);
942 if (has_glob_specials(glob)) {
943 for_each_glob_ref(string_list_add_one_ref, glob, list);
944 } else {
945 unsigned char sha1[20];
946 if (get_sha1(glob, sha1))
947 warning("notes ref %s is invalid", glob);
948 if (!unsorted_string_list_has_string(list, glob))
949 string_list_append(list, glob);
953 void string_list_add_refs_from_colon_sep(struct string_list *list,
954 const char *globs)
956 struct string_list split = STRING_LIST_INIT_NODUP;
957 char *globs_copy = xstrdup(globs);
958 int i;
960 string_list_split_in_place(&split, globs_copy, ':', -1);
961 string_list_remove_empty_items(&split, 0);
963 for (i = 0; i < split.nr; i++)
964 string_list_add_refs_by_glob(list, split.items[i].string);
966 string_list_clear(&split, 0);
967 free(globs_copy);
970 static int notes_display_config(const char *k, const char *v, void *cb)
972 int *load_refs = cb;
974 if (*load_refs && !strcmp(k, "notes.displayref")) {
975 if (!v)
976 config_error_nonbool(k);
977 string_list_add_refs_by_glob(&display_notes_refs, v);
980 return 0;
983 const char *default_notes_ref(void)
985 const char *notes_ref = NULL;
986 if (!notes_ref)
987 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
988 if (!notes_ref)
989 notes_ref = notes_ref_name; /* value of core.notesRef config */
990 if (!notes_ref)
991 notes_ref = GIT_NOTES_DEFAULT_REF;
992 return notes_ref;
995 void init_notes(struct notes_tree *t, const char *notes_ref,
996 combine_notes_fn combine_notes, int flags)
998 struct object_id oid, object_oid;
999 unsigned mode;
1000 struct leaf_node root_tree;
1002 if (!t)
1003 t = &default_notes_tree;
1004 assert(!t->initialized);
1006 if (!notes_ref)
1007 notes_ref = default_notes_ref();
1009 if (!combine_notes)
1010 combine_notes = combine_notes_concatenate;
1012 t->root = (struct int_node *) xcalloc(1, sizeof(struct int_node));
1013 t->first_non_note = NULL;
1014 t->prev_non_note = NULL;
1015 t->ref = xstrdup_or_null(notes_ref);
1016 t->update_ref = (flags & NOTES_INIT_WRITABLE) ? t->ref : NULL;
1017 t->combine_notes = combine_notes;
1018 t->initialized = 1;
1019 t->dirty = 0;
1021 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
1022 get_sha1_treeish(notes_ref, object_oid.hash))
1023 return;
1024 if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, object_oid.hash))
1025 die("Cannot use notes ref %s", notes_ref);
1026 if (get_tree_entry(object_oid.hash, "", oid.hash, &mode))
1027 die("Failed to read notes tree referenced by %s (%s)",
1028 notes_ref, oid_to_hex(&object_oid));
1030 hashclr(root_tree.key_sha1);
1031 hashcpy(root_tree.val_sha1, oid.hash);
1032 load_subtree(t, &root_tree, t->root, 0);
1035 struct notes_tree **load_notes_trees(struct string_list *refs, int flags)
1037 struct string_list_item *item;
1038 int counter = 0;
1039 struct notes_tree **trees;
1040 ALLOC_ARRAY(trees, refs->nr + 1);
1041 for_each_string_list_item(item, refs) {
1042 struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
1043 init_notes(t, item->string, combine_notes_ignore, flags);
1044 trees[counter++] = t;
1046 trees[counter] = NULL;
1047 return trees;
1050 void init_display_notes(struct display_notes_opt *opt)
1052 char *display_ref_env;
1053 int load_config_refs = 0;
1054 display_notes_refs.strdup_strings = 1;
1056 assert(!display_notes_trees);
1058 if (!opt || opt->use_default_notes > 0 ||
1059 (opt->use_default_notes == -1 && !opt->extra_notes_refs.nr)) {
1060 string_list_append(&display_notes_refs, default_notes_ref());
1061 display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
1062 if (display_ref_env) {
1063 string_list_add_refs_from_colon_sep(&display_notes_refs,
1064 display_ref_env);
1065 load_config_refs = 0;
1066 } else
1067 load_config_refs = 1;
1070 git_config(notes_display_config, &load_config_refs);
1072 if (opt) {
1073 struct string_list_item *item;
1074 for_each_string_list_item(item, &opt->extra_notes_refs)
1075 string_list_add_refs_by_glob(&display_notes_refs,
1076 item->string);
1079 display_notes_trees = load_notes_trees(&display_notes_refs, 0);
1080 string_list_clear(&display_notes_refs, 0);
1083 int add_note(struct notes_tree *t, const unsigned char *object_sha1,
1084 const unsigned char *note_sha1, combine_notes_fn combine_notes)
1086 struct leaf_node *l;
1088 if (!t)
1089 t = &default_notes_tree;
1090 assert(t->initialized);
1091 t->dirty = 1;
1092 if (!combine_notes)
1093 combine_notes = t->combine_notes;
1094 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
1095 hashcpy(l->key_sha1, object_sha1);
1096 hashcpy(l->val_sha1, note_sha1);
1097 return note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
1100 int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1102 struct leaf_node l;
1104 if (!t)
1105 t = &default_notes_tree;
1106 assert(t->initialized);
1107 hashcpy(l.key_sha1, object_sha1);
1108 hashclr(l.val_sha1);
1109 note_tree_remove(t, t->root, 0, &l);
1110 if (is_null_sha1(l.val_sha1)) /* no note was removed */
1111 return 1;
1112 t->dirty = 1;
1113 return 0;
1116 const unsigned char *get_note(struct notes_tree *t,
1117 const unsigned char *object_sha1)
1119 struct leaf_node *found;
1121 if (!t)
1122 t = &default_notes_tree;
1123 assert(t->initialized);
1124 found = note_tree_find(t, t->root, 0, object_sha1);
1125 return found ? found->val_sha1 : NULL;
1128 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
1129 void *cb_data)
1131 if (!t)
1132 t = &default_notes_tree;
1133 assert(t->initialized);
1134 return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
1137 int write_notes_tree(struct notes_tree *t, unsigned char *result)
1139 struct tree_write_stack root;
1140 struct write_each_note_data cb_data;
1141 int ret;
1143 if (!t)
1144 t = &default_notes_tree;
1145 assert(t->initialized);
1147 /* Prepare for traversal of current notes tree */
1148 root.next = NULL; /* last forward entry in list is grounded */
1149 strbuf_init(&root.buf, 256 * (32 + 40)); /* assume 256 entries */
1150 root.path[0] = root.path[1] = '\0';
1151 cb_data.root = &root;
1152 cb_data.next_non_note = t->first_non_note;
1154 /* Write tree objects representing current notes tree */
1155 ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
1156 FOR_EACH_NOTE_YIELD_SUBTREES,
1157 write_each_note, &cb_data) ||
1158 write_each_non_note_until(NULL, &cb_data) ||
1159 tree_write_stack_finish_subtree(&root) ||
1160 write_sha1_file(root.buf.buf, root.buf.len, tree_type, result);
1161 strbuf_release(&root.buf);
1162 return ret;
1165 void prune_notes(struct notes_tree *t, int flags)
1167 struct note_delete_list *l = NULL;
1169 if (!t)
1170 t = &default_notes_tree;
1171 assert(t->initialized);
1173 for_each_note(t, 0, prune_notes_helper, &l);
1175 while (l) {
1176 if (flags & NOTES_PRUNE_VERBOSE)
1177 printf("%s\n", sha1_to_hex(l->sha1));
1178 if (!(flags & NOTES_PRUNE_DRYRUN))
1179 remove_note(t, l->sha1);
1180 l = l->next;
1184 void free_notes(struct notes_tree *t)
1186 if (!t)
1187 t = &default_notes_tree;
1188 if (t->root)
1189 note_tree_free(t->root);
1190 free(t->root);
1191 while (t->first_non_note) {
1192 t->prev_non_note = t->first_non_note->next;
1193 free(t->first_non_note->path);
1194 free(t->first_non_note);
1195 t->first_non_note = t->prev_non_note;
1197 free(t->ref);
1198 memset(t, 0, sizeof(struct notes_tree));
1202 * Fill the given strbuf with the notes associated with the given object.
1204 * If the given notes_tree structure is not initialized, it will be auto-
1205 * initialized to the default value (see documentation for init_notes() above).
1206 * If the given notes_tree is NULL, the internal/default notes_tree will be
1207 * used instead.
1209 * (raw != 0) gives the %N userformat; otherwise, the note message is given
1210 * for human consumption.
1212 static void format_note(struct notes_tree *t, const unsigned char *object_sha1,
1213 struct strbuf *sb, const char *output_encoding, int raw)
1215 static const char utf8[] = "utf-8";
1216 const unsigned char *sha1;
1217 char *msg, *msg_p;
1218 unsigned long linelen, msglen;
1219 enum object_type type;
1221 if (!t)
1222 t = &default_notes_tree;
1223 if (!t->initialized)
1224 init_notes(t, NULL, NULL, 0);
1226 sha1 = get_note(t, object_sha1);
1227 if (!sha1)
1228 return;
1230 if (!(msg = read_sha1_file(sha1, &type, &msglen)) || type != OBJ_BLOB) {
1231 free(msg);
1232 return;
1235 if (output_encoding && *output_encoding &&
1236 !is_encoding_utf8(output_encoding)) {
1237 char *reencoded = reencode_string(msg, output_encoding, utf8);
1238 if (reencoded) {
1239 free(msg);
1240 msg = reencoded;
1241 msglen = strlen(msg);
1245 /* we will end the annotation by a newline anyway */
1246 if (msglen && msg[msglen - 1] == '\n')
1247 msglen--;
1249 if (!raw) {
1250 const char *ref = t->ref;
1251 if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
1252 strbuf_addstr(sb, "\nNotes:\n");
1253 } else {
1254 if (starts_with(ref, "refs/"))
1255 ref += 5;
1256 if (starts_with(ref, "notes/"))
1257 ref += 6;
1258 strbuf_addf(sb, "\nNotes (%s):\n", ref);
1262 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
1263 linelen = strchrnul(msg_p, '\n') - msg_p;
1265 if (!raw)
1266 strbuf_addstr(sb, " ");
1267 strbuf_add(sb, msg_p, linelen);
1268 strbuf_addch(sb, '\n');
1271 free(msg);
1274 void format_display_notes(const unsigned char *object_sha1,
1275 struct strbuf *sb, const char *output_encoding, int raw)
1277 int i;
1278 assert(display_notes_trees);
1279 for (i = 0; display_notes_trees[i]; i++)
1280 format_note(display_notes_trees[i], object_sha1, sb,
1281 output_encoding, raw);
1284 int copy_note(struct notes_tree *t,
1285 const unsigned char *from_obj, const unsigned char *to_obj,
1286 int force, combine_notes_fn combine_notes)
1288 const unsigned char *note = get_note(t, from_obj);
1289 const unsigned char *existing_note = get_note(t, to_obj);
1291 if (!force && existing_note)
1292 return 1;
1294 if (note)
1295 return add_note(t, to_obj, note, combine_notes);
1296 else if (existing_note)
1297 return add_note(t, to_obj, null_sha1, combine_notes);
1299 return 0;
1302 void expand_notes_ref(struct strbuf *sb)
1304 if (starts_with(sb->buf, "refs/notes/"))
1305 return; /* we're happy */
1306 else if (starts_with(sb->buf, "notes/"))
1307 strbuf_insert(sb, 0, "refs/", 5);
1308 else
1309 strbuf_insert(sb, 0, "refs/notes/", 11);
1312 void expand_loose_notes_ref(struct strbuf *sb)
1314 unsigned char object[20];
1316 if (get_sha1(sb->buf, object)) {
1317 /* fallback to expand_notes_ref */
1318 expand_notes_ref(sb);