gitk: Second try to work around the command line limit on Windows
[git/dscho.git] / notes.c
blobe425e198278bfb5c6a039dc88825568f1518e875
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;
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 * To insert a leaf_node:
154 * Search to the tree location appropriate for the given leaf_node's key:
155 * - If location is unused (NULL), store the tweaked pointer directly there
156 * - If location holds a note entry that matches the note-to-be-inserted, then
157 * combine the two notes (by calling the given combine_notes function).
158 * - If location holds a note entry that matches the subtree-to-be-inserted,
159 * then unpack the subtree-to-be-inserted into the location.
160 * - If location holds a matching subtree entry, unpack the subtree at that
161 * location, and restart the insert operation from that level.
162 * - Else, create a new int_node, holding both the node-at-location and the
163 * node-to-be-inserted, and store the new int_node into the location.
165 static void note_tree_insert(struct notes_tree *t, struct int_node *tree,
166 unsigned char n, struct leaf_node *entry, unsigned char type,
167 combine_notes_fn combine_notes)
169 struct int_node *new_node;
170 struct leaf_node *l;
171 void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
173 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
174 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
175 switch (GET_PTR_TYPE(*p)) {
176 case PTR_TYPE_NULL:
177 assert(!*p);
178 *p = SET_PTR_TYPE(entry, type);
179 return;
180 case PTR_TYPE_NOTE:
181 switch (type) {
182 case PTR_TYPE_NOTE:
183 if (!hashcmp(l->key_sha1, entry->key_sha1)) {
184 /* skip concatenation if l == entry */
185 if (!hashcmp(l->val_sha1, entry->val_sha1))
186 return;
188 if (combine_notes(l->val_sha1, entry->val_sha1))
189 die("failed to combine notes %s and %s"
190 " for object %s",
191 sha1_to_hex(l->val_sha1),
192 sha1_to_hex(entry->val_sha1),
193 sha1_to_hex(l->key_sha1));
194 free(entry);
195 return;
197 break;
198 case PTR_TYPE_SUBTREE:
199 if (!SUBTREE_SHA1_PREFIXCMP(l->key_sha1,
200 entry->key_sha1)) {
201 /* unpack 'entry' */
202 load_subtree(t, entry, tree, n);
203 free(entry);
204 return;
206 break;
208 break;
209 case PTR_TYPE_SUBTREE:
210 if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) {
211 /* unpack 'l' and restart insert */
212 *p = NULL;
213 load_subtree(t, l, tree, n);
214 free(l);
215 note_tree_insert(t, tree, n, entry, type,
216 combine_notes);
217 return;
219 break;
222 /* non-matching leaf_node */
223 assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
224 GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
225 new_node = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
226 note_tree_insert(t, new_node, n + 1, l, GET_PTR_TYPE(*p),
227 combine_notes);
228 *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
229 note_tree_insert(t, new_node, n + 1, entry, type, combine_notes);
233 * How to consolidate an int_node:
234 * If there are > 1 non-NULL entries, give up and return non-zero.
235 * Otherwise replace the int_node at the given index in the given parent node
236 * with the only entry (or a NULL entry if no entries) from the given tree,
237 * and return 0.
239 static int note_tree_consolidate(struct int_node *tree,
240 struct int_node *parent, unsigned char index)
242 unsigned int i;
243 void *p = NULL;
245 assert(tree && parent);
246 assert(CLR_PTR_TYPE(parent->a[index]) == tree);
248 for (i = 0; i < 16; i++) {
249 if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) {
250 if (p) /* more than one entry */
251 return -2;
252 p = tree->a[i];
256 /* replace tree with p in parent[index] */
257 parent->a[index] = p;
258 free(tree);
259 return 0;
263 * To remove a leaf_node:
264 * Search to the tree location appropriate for the given leaf_node's key:
265 * - If location does not hold a matching entry, abort and do nothing.
266 * - Replace the matching leaf_node with a NULL entry (and free the leaf_node).
267 * - Consolidate int_nodes repeatedly, while walking up the tree towards root.
269 static void note_tree_remove(struct notes_tree *t, struct int_node *tree,
270 unsigned char n, struct leaf_node *entry)
272 struct leaf_node *l;
273 struct int_node *parent_stack[20];
274 unsigned char i, j;
275 void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
277 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
278 if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
279 return; /* type mismatch, nothing to remove */
280 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
281 if (hashcmp(l->key_sha1, entry->key_sha1))
282 return; /* key mismatch, nothing to remove */
284 /* we have found a matching entry */
285 free(l);
286 *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
288 /* consolidate this tree level, and parent levels, if possible */
289 if (!n)
290 return; /* cannot consolidate top level */
291 /* first, build stack of ancestors between root and current node */
292 parent_stack[0] = t->root;
293 for (i = 0; i < n; i++) {
294 j = GET_NIBBLE(i, entry->key_sha1);
295 parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]);
297 assert(i == n && parent_stack[i] == tree);
298 /* next, unwind stack until note_tree_consolidate() is done */
299 while (i > 0 &&
300 !note_tree_consolidate(parent_stack[i], parent_stack[i - 1],
301 GET_NIBBLE(i - 1, entry->key_sha1)))
302 i--;
305 /* Free the entire notes data contained in the given tree */
306 static void note_tree_free(struct int_node *tree)
308 unsigned int i;
309 for (i = 0; i < 16; i++) {
310 void *p = tree->a[i];
311 switch (GET_PTR_TYPE(p)) {
312 case PTR_TYPE_INTERNAL:
313 note_tree_free(CLR_PTR_TYPE(p));
314 /* fall through */
315 case PTR_TYPE_NOTE:
316 case PTR_TYPE_SUBTREE:
317 free(CLR_PTR_TYPE(p));
323 * Convert a partial SHA1 hex string to the corresponding partial SHA1 value.
324 * - hex - Partial SHA1 segment in ASCII hex format
325 * - hex_len - Length of above segment. Must be multiple of 2 between 0 and 40
326 * - sha1 - Partial SHA1 value is written here
327 * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20
328 * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format)).
329 * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2).
330 * Pads sha1 with NULs up to sha1_len (not included in returned length).
332 static int get_sha1_hex_segment(const char *hex, unsigned int hex_len,
333 unsigned char *sha1, unsigned int sha1_len)
335 unsigned int i, len = hex_len >> 1;
336 if (hex_len % 2 != 0 || len > sha1_len)
337 return -1;
338 for (i = 0; i < len; i++) {
339 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
340 if (val & ~0xff)
341 return -1;
342 *sha1++ = val;
343 hex += 2;
345 for (; i < sha1_len; i++)
346 *sha1++ = 0;
347 return len;
350 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
352 return strcmp(a->path, b->path);
355 static void add_non_note(struct notes_tree *t, const char *path,
356 unsigned int mode, const unsigned char *sha1)
358 struct non_note *p = t->prev_non_note, *n;
359 n = (struct non_note *) xmalloc(sizeof(struct non_note));
360 n->next = NULL;
361 n->path = xstrdup(path);
362 n->mode = mode;
363 hashcpy(n->sha1, sha1);
364 t->prev_non_note = n;
366 if (!t->first_non_note) {
367 t->first_non_note = n;
368 return;
371 if (non_note_cmp(p, n) < 0)
372 ; /* do nothing */
373 else if (non_note_cmp(t->first_non_note, n) <= 0)
374 p = t->first_non_note;
375 else {
376 /* n sorts before t->first_non_note */
377 n->next = t->first_non_note;
378 t->first_non_note = n;
379 return;
382 /* n sorts equal or after p */
383 while (p->next && non_note_cmp(p->next, n) <= 0)
384 p = p->next;
386 if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
387 assert(strcmp(p->path, n->path) == 0);
388 p->mode = n->mode;
389 hashcpy(p->sha1, n->sha1);
390 free(n);
391 t->prev_non_note = p;
392 return;
395 /* n sorts between p and p->next */
396 n->next = p->next;
397 p->next = n;
400 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
401 struct int_node *node, unsigned int n)
403 unsigned char object_sha1[20];
404 unsigned int prefix_len;
405 void *buf;
406 struct tree_desc desc;
407 struct name_entry entry;
408 int len, path_len;
409 unsigned char type;
410 struct leaf_node *l;
412 buf = fill_tree_descriptor(&desc, subtree->val_sha1);
413 if (!buf)
414 die("Could not read %s for notes-index",
415 sha1_to_hex(subtree->val_sha1));
417 prefix_len = subtree->key_sha1[19];
418 assert(prefix_len * 2 >= n);
419 memcpy(object_sha1, subtree->key_sha1, prefix_len);
420 while (tree_entry(&desc, &entry)) {
421 path_len = strlen(entry.path);
422 len = get_sha1_hex_segment(entry.path, path_len,
423 object_sha1 + prefix_len, 20 - prefix_len);
424 if (len < 0)
425 goto handle_non_note; /* entry.path is not a SHA1 */
426 len += prefix_len;
429 * If object SHA1 is complete (len == 20), assume note object
430 * If object SHA1 is incomplete (len < 20), and current
431 * component consists of 2 hex chars, assume note subtree
433 if (len <= 20) {
434 type = PTR_TYPE_NOTE;
435 l = (struct leaf_node *)
436 xcalloc(sizeof(struct leaf_node), 1);
437 hashcpy(l->key_sha1, object_sha1);
438 hashcpy(l->val_sha1, entry.sha1);
439 if (len < 20) {
440 if (!S_ISDIR(entry.mode) || path_len != 2)
441 goto handle_non_note; /* not subtree */
442 l->key_sha1[19] = (unsigned char) len;
443 type = PTR_TYPE_SUBTREE;
445 note_tree_insert(t, node, n, l, type,
446 combine_notes_concatenate);
448 continue;
450 handle_non_note:
452 * Determine full path for this non-note entry:
453 * The filename is already found in entry.path, but the
454 * directory part of the path must be deduced from the subtree
455 * containing this entry. We assume here that the overall notes
456 * tree follows a strict byte-based progressive fanout
457 * structure (i.e. using 2/38, 2/2/36, etc. fanouts, and not
458 * e.g. 4/36 fanout). This means that if a non-note is found at
459 * path "dead/beef", the following code will register it as
460 * being found on "de/ad/beef".
461 * On the other hand, if you use such non-obvious non-note
462 * paths in the middle of a notes tree, you deserve what's
463 * coming to you ;). Note that for non-notes that are not
464 * SHA1-like at the top level, there will be no problems.
466 * To conclude, it is strongly advised to make sure non-notes
467 * have at least one non-hex character in the top-level path
468 * component.
471 char non_note_path[PATH_MAX];
472 char *p = non_note_path;
473 const char *q = sha1_to_hex(subtree->key_sha1);
474 int i;
475 for (i = 0; i < prefix_len; i++) {
476 *p++ = *q++;
477 *p++ = *q++;
478 *p++ = '/';
480 strcpy(p, entry.path);
481 add_non_note(t, non_note_path, entry.mode, entry.sha1);
484 free(buf);
488 * Determine optimal on-disk fanout for this part of the notes tree
490 * Given a (sub)tree and the level in the internal tree structure, determine
491 * whether or not the given existing fanout should be expanded for this
492 * (sub)tree.
494 * Values of the 'fanout' variable:
495 * - 0: No fanout (all notes are stored directly in the root notes tree)
496 * - 1: 2/38 fanout
497 * - 2: 2/2/36 fanout
498 * - 3: 2/2/2/34 fanout
499 * etc.
501 static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
502 unsigned char fanout)
505 * The following is a simple heuristic that works well in practice:
506 * For each even-numbered 16-tree level (remember that each on-disk
507 * fanout level corresponds to _two_ 16-tree levels), peek at all 16
508 * entries at that tree level. If all of them are either int_nodes or
509 * subtree entries, then there are likely plenty of notes below this
510 * level, so we return an incremented fanout.
512 unsigned int i;
513 if ((n % 2) || (n > 2 * fanout))
514 return fanout;
515 for (i = 0; i < 16; i++) {
516 switch (GET_PTR_TYPE(tree->a[i])) {
517 case PTR_TYPE_SUBTREE:
518 case PTR_TYPE_INTERNAL:
519 continue;
520 default:
521 return fanout;
524 return fanout + 1;
527 static void construct_path_with_fanout(const unsigned char *sha1,
528 unsigned char fanout, char *path)
530 unsigned int i = 0, j = 0;
531 const char *hex_sha1 = sha1_to_hex(sha1);
532 assert(fanout < 20);
533 while (fanout) {
534 path[i++] = hex_sha1[j++];
535 path[i++] = hex_sha1[j++];
536 path[i++] = '/';
537 fanout--;
539 strcpy(path + i, hex_sha1 + j);
542 static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
543 unsigned char n, unsigned char fanout, int flags,
544 each_note_fn fn, void *cb_data)
546 unsigned int i;
547 void *p;
548 int ret = 0;
549 struct leaf_node *l;
550 static char path[40 + 19 + 1]; /* hex SHA1 + 19 * '/' + NUL */
552 fanout = determine_fanout(tree, n, fanout);
553 for (i = 0; i < 16; i++) {
554 redo:
555 p = tree->a[i];
556 switch (GET_PTR_TYPE(p)) {
557 case PTR_TYPE_INTERNAL:
558 /* recurse into int_node */
559 ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
560 fanout, flags, fn, cb_data);
561 break;
562 case PTR_TYPE_SUBTREE:
563 l = (struct leaf_node *) CLR_PTR_TYPE(p);
565 * Subtree entries in the note tree represent parts of
566 * the note tree that have not yet been explored. There
567 * is a direct relationship between subtree entries at
568 * level 'n' in the tree, and the 'fanout' variable:
569 * Subtree entries at level 'n <= 2 * fanout' should be
570 * preserved, since they correspond exactly to a fanout
571 * directory in the on-disk structure. However, subtree
572 * entries at level 'n > 2 * fanout' should NOT be
573 * preserved, but rather consolidated into the above
574 * notes tree level. We achieve this by unconditionally
575 * unpacking subtree entries that exist below the
576 * threshold level at 'n = 2 * fanout'.
578 if (n <= 2 * fanout &&
579 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
580 /* invoke callback with subtree */
581 unsigned int path_len =
582 l->key_sha1[19] * 2 + fanout;
583 assert(path_len < 40 + 19);
584 construct_path_with_fanout(l->key_sha1, fanout,
585 path);
586 /* Create trailing slash, if needed */
587 if (path[path_len - 1] != '/')
588 path[path_len++] = '/';
589 path[path_len] = '\0';
590 ret = fn(l->key_sha1, l->val_sha1, path,
591 cb_data);
593 if (n > fanout * 2 ||
594 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
595 /* unpack subtree and resume traversal */
596 tree->a[i] = NULL;
597 load_subtree(t, l, tree, n);
598 free(l);
599 goto redo;
601 break;
602 case PTR_TYPE_NOTE:
603 l = (struct leaf_node *) CLR_PTR_TYPE(p);
604 construct_path_with_fanout(l->key_sha1, fanout, path);
605 ret = fn(l->key_sha1, l->val_sha1, path, cb_data);
606 break;
608 if (ret)
609 return ret;
611 return 0;
614 struct tree_write_stack {
615 struct tree_write_stack *next;
616 struct strbuf buf;
617 char path[2]; /* path to subtree in next, if any */
620 static inline int matches_tree_write_stack(struct tree_write_stack *tws,
621 const char *full_path)
623 return full_path[0] == tws->path[0] &&
624 full_path[1] == tws->path[1] &&
625 full_path[2] == '/';
628 static void write_tree_entry(struct strbuf *buf, unsigned int mode,
629 const char *path, unsigned int path_len, const
630 unsigned char *sha1)
632 strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
633 strbuf_add(buf, sha1, 20);
636 static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
637 const char *path)
639 struct tree_write_stack *n;
640 assert(!tws->next);
641 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
642 n = (struct tree_write_stack *)
643 xmalloc(sizeof(struct tree_write_stack));
644 n->next = NULL;
645 strbuf_init(&n->buf, 256 * (32 + 40)); /* assume 256 entries per tree */
646 n->path[0] = n->path[1] = '\0';
647 tws->next = n;
648 tws->path[0] = path[0];
649 tws->path[1] = path[1];
652 static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
654 int ret;
655 struct tree_write_stack *n = tws->next;
656 unsigned char s[20];
657 if (n) {
658 ret = tree_write_stack_finish_subtree(n);
659 if (ret)
660 return ret;
661 ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s);
662 if (ret)
663 return ret;
664 strbuf_release(&n->buf);
665 free(n);
666 tws->next = NULL;
667 write_tree_entry(&tws->buf, 040000, tws->path, 2, s);
668 tws->path[0] = tws->path[1] = '\0';
670 return 0;
673 static int write_each_note_helper(struct tree_write_stack *tws,
674 const char *path, unsigned int mode,
675 const unsigned char *sha1)
677 size_t path_len = strlen(path);
678 unsigned int n = 0;
679 int ret;
681 /* Determine common part of tree write stack */
682 while (tws && 3 * n < path_len &&
683 matches_tree_write_stack(tws, path + 3 * n)) {
684 n++;
685 tws = tws->next;
688 /* tws point to last matching tree_write_stack entry */
689 ret = tree_write_stack_finish_subtree(tws);
690 if (ret)
691 return ret;
693 /* Start subtrees needed to satisfy path */
694 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
695 tree_write_stack_init_subtree(tws, path + 3 * n);
696 n++;
697 tws = tws->next;
700 /* There should be no more directory components in the given path */
701 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
703 /* Finally add given entry to the current tree object */
704 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
705 sha1);
707 return 0;
710 struct write_each_note_data {
711 struct tree_write_stack *root;
712 struct non_note *next_non_note;
715 static int write_each_non_note_until(const char *note_path,
716 struct write_each_note_data *d)
718 struct non_note *n = d->next_non_note;
719 int cmp, ret;
720 while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
721 if (note_path && cmp == 0)
722 ; /* do nothing, prefer note to non-note */
723 else {
724 ret = write_each_note_helper(d->root, n->path, n->mode,
725 n->sha1);
726 if (ret)
727 return ret;
729 n = n->next;
731 d->next_non_note = n;
732 return 0;
735 static int write_each_note(const unsigned char *object_sha1,
736 const unsigned char *note_sha1, char *note_path,
737 void *cb_data)
739 struct write_each_note_data *d =
740 (struct write_each_note_data *) cb_data;
741 size_t note_path_len = strlen(note_path);
742 unsigned int mode = 0100644;
744 if (note_path[note_path_len - 1] == '/') {
745 /* subtree entry */
746 note_path_len--;
747 note_path[note_path_len] = '\0';
748 mode = 040000;
750 assert(note_path_len <= 40 + 19);
752 /* Weave non-note entries into note entries */
753 return write_each_non_note_until(note_path, d) ||
754 write_each_note_helper(d->root, note_path, mode, note_sha1);
757 struct note_delete_list {
758 struct note_delete_list *next;
759 const unsigned char *sha1;
762 static int prune_notes_helper(const unsigned char *object_sha1,
763 const unsigned char *note_sha1, char *note_path,
764 void *cb_data)
766 struct note_delete_list **l = (struct note_delete_list **) cb_data;
767 struct note_delete_list *n;
769 if (has_sha1_file(object_sha1))
770 return 0; /* nothing to do for this note */
772 /* failed to find object => prune this note */
773 n = (struct note_delete_list *) xmalloc(sizeof(*n));
774 n->next = *l;
775 n->sha1 = object_sha1;
776 *l = n;
777 return 0;
780 int combine_notes_concatenate(unsigned char *cur_sha1,
781 const unsigned char *new_sha1)
783 char *cur_msg = NULL, *new_msg = NULL, *buf;
784 unsigned long cur_len, new_len, buf_len;
785 enum object_type cur_type, new_type;
786 int ret;
788 /* read in both note blob objects */
789 if (!is_null_sha1(new_sha1))
790 new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
791 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
792 free(new_msg);
793 return 0;
795 if (!is_null_sha1(cur_sha1))
796 cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
797 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
798 free(cur_msg);
799 free(new_msg);
800 hashcpy(cur_sha1, new_sha1);
801 return 0;
804 /* we will separate the notes by a newline anyway */
805 if (cur_msg[cur_len - 1] == '\n')
806 cur_len--;
808 /* concatenate cur_msg and new_msg into buf */
809 buf_len = cur_len + 1 + new_len;
810 buf = (char *) xmalloc(buf_len);
811 memcpy(buf, cur_msg, cur_len);
812 buf[cur_len] = '\n';
813 memcpy(buf + cur_len + 1, new_msg, new_len);
814 free(cur_msg);
815 free(new_msg);
817 /* create a new blob object from buf */
818 ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
819 free(buf);
820 return ret;
823 int combine_notes_overwrite(unsigned char *cur_sha1,
824 const unsigned char *new_sha1)
826 hashcpy(cur_sha1, new_sha1);
827 return 0;
830 int combine_notes_ignore(unsigned char *cur_sha1,
831 const unsigned char *new_sha1)
833 return 0;
836 static int string_list_add_one_ref(const char *path, const unsigned char *sha1,
837 int flag, void *cb)
839 struct string_list *refs = cb;
840 if (!unsorted_string_list_has_string(refs, path))
841 string_list_append(path, refs);
842 return 0;
845 void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
847 if (has_glob_specials(glob)) {
848 for_each_glob_ref(string_list_add_one_ref, glob, list);
849 } else {
850 unsigned char sha1[20];
851 if (get_sha1(glob, sha1))
852 warning("notes ref %s is invalid", glob);
853 if (!unsorted_string_list_has_string(list, glob))
854 string_list_append(glob, list);
858 void string_list_add_refs_from_colon_sep(struct string_list *list,
859 const char *globs)
861 struct strbuf globbuf = STRBUF_INIT;
862 struct strbuf **split;
863 int i;
865 strbuf_addstr(&globbuf, globs);
866 split = strbuf_split(&globbuf, ':');
868 for (i = 0; split[i]; i++) {
869 if (!split[i]->len)
870 continue;
871 if (split[i]->buf[split[i]->len-1] == ':')
872 strbuf_setlen(split[i], split[i]->len-1);
873 string_list_add_refs_by_glob(list, split[i]->buf);
876 strbuf_list_free(split);
877 strbuf_release(&globbuf);
880 static int string_list_add_refs_from_list(struct string_list_item *item,
881 void *cb)
883 struct string_list *list = cb;
884 string_list_add_refs_by_glob(list, item->string);
885 return 0;
888 static int notes_display_config(const char *k, const char *v, void *cb)
890 int *load_refs = cb;
892 if (*load_refs && !strcmp(k, "notes.displayref")) {
893 if (!v)
894 config_error_nonbool(k);
895 string_list_add_refs_by_glob(&display_notes_refs, v);
898 return 0;
901 static const char *default_notes_ref(void)
903 const char *notes_ref = NULL;
904 if (!notes_ref)
905 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
906 if (!notes_ref)
907 notes_ref = notes_ref_name; /* value of core.notesRef config */
908 if (!notes_ref)
909 notes_ref = GIT_NOTES_DEFAULT_REF;
910 return notes_ref;
913 void init_notes(struct notes_tree *t, const char *notes_ref,
914 combine_notes_fn combine_notes, int flags)
916 unsigned char sha1[20], object_sha1[20];
917 unsigned mode;
918 struct leaf_node root_tree;
920 if (!t)
921 t = &default_notes_tree;
922 assert(!t->initialized);
924 if (!notes_ref)
925 notes_ref = default_notes_ref();
927 if (!combine_notes)
928 combine_notes = combine_notes_concatenate;
930 t->root = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
931 t->first_non_note = NULL;
932 t->prev_non_note = NULL;
933 t->ref = notes_ref ? xstrdup(notes_ref) : NULL;
934 t->combine_notes = combine_notes;
935 t->initialized = 1;
936 t->dirty = 0;
938 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
939 read_ref(notes_ref, object_sha1))
940 return;
941 if (get_tree_entry(object_sha1, "", sha1, &mode))
942 die("Failed to read notes tree referenced by %s (%s)",
943 notes_ref, object_sha1);
945 hashclr(root_tree.key_sha1);
946 hashcpy(root_tree.val_sha1, sha1);
947 load_subtree(t, &root_tree, t->root, 0);
950 struct load_notes_cb_data {
951 int counter;
952 struct notes_tree **trees;
955 static int load_one_display_note_ref(struct string_list_item *item,
956 void *cb_data)
958 struct load_notes_cb_data *c = cb_data;
959 struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
960 init_notes(t, item->string, combine_notes_ignore, 0);
961 c->trees[c->counter++] = t;
962 return 0;
965 struct notes_tree **load_notes_trees(struct string_list *refs)
967 struct notes_tree **trees;
968 struct load_notes_cb_data cb_data;
969 trees = xmalloc((refs->nr+1) * sizeof(struct notes_tree *));
970 cb_data.counter = 0;
971 cb_data.trees = trees;
972 for_each_string_list(load_one_display_note_ref, refs, &cb_data);
973 trees[cb_data.counter] = NULL;
974 return trees;
977 void init_display_notes(struct display_notes_opt *opt)
979 char *display_ref_env;
980 int load_config_refs = 0;
981 display_notes_refs.strdup_strings = 1;
983 assert(!display_notes_trees);
985 if (!opt || !opt->suppress_default_notes) {
986 string_list_append(default_notes_ref(), &display_notes_refs);
987 display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
988 if (display_ref_env) {
989 string_list_add_refs_from_colon_sep(&display_notes_refs,
990 display_ref_env);
991 load_config_refs = 0;
992 } else
993 load_config_refs = 1;
996 git_config(notes_display_config, &load_config_refs);
998 if (opt && opt->extra_notes_refs)
999 for_each_string_list(string_list_add_refs_from_list,
1000 opt->extra_notes_refs,
1001 &display_notes_refs);
1003 display_notes_trees = load_notes_trees(&display_notes_refs);
1004 string_list_clear(&display_notes_refs, 0);
1007 void add_note(struct notes_tree *t, const unsigned char *object_sha1,
1008 const unsigned char *note_sha1, combine_notes_fn combine_notes)
1010 struct leaf_node *l;
1012 if (!t)
1013 t = &default_notes_tree;
1014 assert(t->initialized);
1015 t->dirty = 1;
1016 if (!combine_notes)
1017 combine_notes = t->combine_notes;
1018 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
1019 hashcpy(l->key_sha1, object_sha1);
1020 hashcpy(l->val_sha1, note_sha1);
1021 note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
1024 void remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1026 struct leaf_node l;
1028 if (!t)
1029 t = &default_notes_tree;
1030 assert(t->initialized);
1031 t->dirty = 1;
1032 hashcpy(l.key_sha1, object_sha1);
1033 hashclr(l.val_sha1);
1034 note_tree_remove(t, t->root, 0, &l);
1037 const unsigned char *get_note(struct notes_tree *t,
1038 const unsigned char *object_sha1)
1040 struct leaf_node *found;
1042 if (!t)
1043 t = &default_notes_tree;
1044 assert(t->initialized);
1045 found = note_tree_find(t, t->root, 0, object_sha1);
1046 return found ? found->val_sha1 : NULL;
1049 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
1050 void *cb_data)
1052 if (!t)
1053 t = &default_notes_tree;
1054 assert(t->initialized);
1055 return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
1058 int write_notes_tree(struct notes_tree *t, unsigned char *result)
1060 struct tree_write_stack root;
1061 struct write_each_note_data cb_data;
1062 int ret;
1064 if (!t)
1065 t = &default_notes_tree;
1066 assert(t->initialized);
1068 /* Prepare for traversal of current notes tree */
1069 root.next = NULL; /* last forward entry in list is grounded */
1070 strbuf_init(&root.buf, 256 * (32 + 40)); /* assume 256 entries */
1071 root.path[0] = root.path[1] = '\0';
1072 cb_data.root = &root;
1073 cb_data.next_non_note = t->first_non_note;
1075 /* Write tree objects representing current notes tree */
1076 ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
1077 FOR_EACH_NOTE_YIELD_SUBTREES,
1078 write_each_note, &cb_data) ||
1079 write_each_non_note_until(NULL, &cb_data) ||
1080 tree_write_stack_finish_subtree(&root) ||
1081 write_sha1_file(root.buf.buf, root.buf.len, tree_type, result);
1082 strbuf_release(&root.buf);
1083 return ret;
1086 void prune_notes(struct notes_tree *t)
1088 struct note_delete_list *l = NULL;
1090 if (!t)
1091 t = &default_notes_tree;
1092 assert(t->initialized);
1094 for_each_note(t, 0, prune_notes_helper, &l);
1096 while (l) {
1097 remove_note(t, l->sha1);
1098 l = l->next;
1102 void free_notes(struct notes_tree *t)
1104 if (!t)
1105 t = &default_notes_tree;
1106 if (t->root)
1107 note_tree_free(t->root);
1108 free(t->root);
1109 while (t->first_non_note) {
1110 t->prev_non_note = t->first_non_note->next;
1111 free(t->first_non_note->path);
1112 free(t->first_non_note);
1113 t->first_non_note = t->prev_non_note;
1115 free(t->ref);
1116 memset(t, 0, sizeof(struct notes_tree));
1119 void format_note(struct notes_tree *t, const unsigned char *object_sha1,
1120 struct strbuf *sb, const char *output_encoding, int flags)
1122 static const char utf8[] = "utf-8";
1123 const unsigned char *sha1;
1124 char *msg, *msg_p;
1125 unsigned long linelen, msglen;
1126 enum object_type type;
1128 if (!t)
1129 t = &default_notes_tree;
1130 if (!t->initialized)
1131 init_notes(t, NULL, NULL, 0);
1133 sha1 = get_note(t, object_sha1);
1134 if (!sha1)
1135 return;
1137 if (!(msg = read_sha1_file(sha1, &type, &msglen)) || !msglen ||
1138 type != OBJ_BLOB) {
1139 free(msg);
1140 return;
1143 if (output_encoding && *output_encoding &&
1144 strcmp(utf8, output_encoding)) {
1145 char *reencoded = reencode_string(msg, output_encoding, utf8);
1146 if (reencoded) {
1147 free(msg);
1148 msg = reencoded;
1149 msglen = strlen(msg);
1153 /* we will end the annotation by a newline anyway */
1154 if (msglen && msg[msglen - 1] == '\n')
1155 msglen--;
1157 if (flags & NOTES_SHOW_HEADER) {
1158 const char *ref = t->ref;
1159 if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
1160 strbuf_addstr(sb, "\nNotes:\n");
1161 } else {
1162 if (!prefixcmp(ref, "refs/"))
1163 ref += 5;
1164 if (!prefixcmp(ref, "notes/"))
1165 ref += 6;
1166 strbuf_addf(sb, "\nNotes (%s):\n", ref);
1170 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
1171 linelen = strchrnul(msg_p, '\n') - msg_p;
1173 if (flags & NOTES_INDENT)
1174 strbuf_addstr(sb, " ");
1175 strbuf_add(sb, msg_p, linelen);
1176 strbuf_addch(sb, '\n');
1179 free(msg);
1182 void format_display_notes(const unsigned char *object_sha1,
1183 struct strbuf *sb, const char *output_encoding, int flags)
1185 int i;
1186 assert(display_notes_trees);
1187 for (i = 0; display_notes_trees[i]; i++)
1188 format_note(display_notes_trees[i], object_sha1, sb,
1189 output_encoding, flags);
1192 int copy_note(struct notes_tree *t,
1193 const unsigned char *from_obj, const unsigned char *to_obj,
1194 int force, combine_notes_fn combine_fn)
1196 const unsigned char *note = get_note(t, from_obj);
1197 const unsigned char *existing_note = get_note(t, to_obj);
1199 if (!force && existing_note)
1200 return 1;
1202 if (note)
1203 add_note(t, to_obj, note, combine_fn);
1204 else if (existing_note)
1205 add_note(t, to_obj, null_sha1, combine_fn);
1207 return 0;