Merge branch 'cb/maint-orphan-merge-noclobber'
[git/kirr.git] / notes.c
blob70d00135eb5b67cd6f21b416cde2ae4a1967fd0a
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 * - Copy the matching entry's value into the given entry.
267 * - Replace the matching leaf_node with a NULL entry (and free the leaf_node).
268 * - Consolidate int_nodes repeatedly, while walking up the tree towards root.
270 static void note_tree_remove(struct notes_tree *t,
271 struct int_node *tree, unsigned char n,
272 struct leaf_node *entry)
274 struct leaf_node *l;
275 struct int_node *parent_stack[20];
276 unsigned char i, j;
277 void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
279 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
280 if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
281 return; /* type mismatch, nothing to remove */
282 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
283 if (hashcmp(l->key_sha1, entry->key_sha1))
284 return; /* key mismatch, nothing to remove */
286 /* we have found a matching entry */
287 hashcpy(entry->val_sha1, l->val_sha1);
288 free(l);
289 *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
291 /* consolidate this tree level, and parent levels, if possible */
292 if (!n)
293 return; /* cannot consolidate top level */
294 /* first, build stack of ancestors between root and current node */
295 parent_stack[0] = t->root;
296 for (i = 0; i < n; i++) {
297 j = GET_NIBBLE(i, entry->key_sha1);
298 parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]);
300 assert(i == n && parent_stack[i] == tree);
301 /* next, unwind stack until note_tree_consolidate() is done */
302 while (i > 0 &&
303 !note_tree_consolidate(parent_stack[i], parent_stack[i - 1],
304 GET_NIBBLE(i - 1, entry->key_sha1)))
305 i--;
308 /* Free the entire notes data contained in the given tree */
309 static void note_tree_free(struct int_node *tree)
311 unsigned int i;
312 for (i = 0; i < 16; i++) {
313 void *p = tree->a[i];
314 switch (GET_PTR_TYPE(p)) {
315 case PTR_TYPE_INTERNAL:
316 note_tree_free(CLR_PTR_TYPE(p));
317 /* fall through */
318 case PTR_TYPE_NOTE:
319 case PTR_TYPE_SUBTREE:
320 free(CLR_PTR_TYPE(p));
326 * Convert a partial SHA1 hex string to the corresponding partial SHA1 value.
327 * - hex - Partial SHA1 segment in ASCII hex format
328 * - hex_len - Length of above segment. Must be multiple of 2 between 0 and 40
329 * - sha1 - Partial SHA1 value is written here
330 * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20
331 * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format)).
332 * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2).
333 * Pads sha1 with NULs up to sha1_len (not included in returned length).
335 static int get_sha1_hex_segment(const char *hex, unsigned int hex_len,
336 unsigned char *sha1, unsigned int sha1_len)
338 unsigned int i, len = hex_len >> 1;
339 if (hex_len % 2 != 0 || len > sha1_len)
340 return -1;
341 for (i = 0; i < len; i++) {
342 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
343 if (val & ~0xff)
344 return -1;
345 *sha1++ = val;
346 hex += 2;
348 for (; i < sha1_len; i++)
349 *sha1++ = 0;
350 return len;
353 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
355 return strcmp(a->path, b->path);
358 static void add_non_note(struct notes_tree *t, const char *path,
359 unsigned int mode, const unsigned char *sha1)
361 struct non_note *p = t->prev_non_note, *n;
362 n = (struct non_note *) xmalloc(sizeof(struct non_note));
363 n->next = NULL;
364 n->path = xstrdup(path);
365 n->mode = mode;
366 hashcpy(n->sha1, sha1);
367 t->prev_non_note = n;
369 if (!t->first_non_note) {
370 t->first_non_note = n;
371 return;
374 if (non_note_cmp(p, n) < 0)
375 ; /* do nothing */
376 else if (non_note_cmp(t->first_non_note, n) <= 0)
377 p = t->first_non_note;
378 else {
379 /* n sorts before t->first_non_note */
380 n->next = t->first_non_note;
381 t->first_non_note = n;
382 return;
385 /* n sorts equal or after p */
386 while (p->next && non_note_cmp(p->next, n) <= 0)
387 p = p->next;
389 if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
390 assert(strcmp(p->path, n->path) == 0);
391 p->mode = n->mode;
392 hashcpy(p->sha1, n->sha1);
393 free(n);
394 t->prev_non_note = p;
395 return;
398 /* n sorts between p and p->next */
399 n->next = p->next;
400 p->next = n;
403 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
404 struct int_node *node, unsigned int n)
406 unsigned char object_sha1[20];
407 unsigned int prefix_len;
408 void *buf;
409 struct tree_desc desc;
410 struct name_entry entry;
411 int len, path_len;
412 unsigned char type;
413 struct leaf_node *l;
415 buf = fill_tree_descriptor(&desc, subtree->val_sha1);
416 if (!buf)
417 die("Could not read %s for notes-index",
418 sha1_to_hex(subtree->val_sha1));
420 prefix_len = subtree->key_sha1[19];
421 assert(prefix_len * 2 >= n);
422 memcpy(object_sha1, subtree->key_sha1, prefix_len);
423 while (tree_entry(&desc, &entry)) {
424 path_len = strlen(entry.path);
425 len = get_sha1_hex_segment(entry.path, path_len,
426 object_sha1 + prefix_len, 20 - prefix_len);
427 if (len < 0)
428 goto handle_non_note; /* entry.path is not a SHA1 */
429 len += prefix_len;
432 * If object SHA1 is complete (len == 20), assume note object
433 * If object SHA1 is incomplete (len < 20), and current
434 * component consists of 2 hex chars, assume note subtree
436 if (len <= 20) {
437 type = PTR_TYPE_NOTE;
438 l = (struct leaf_node *)
439 xcalloc(sizeof(struct leaf_node), 1);
440 hashcpy(l->key_sha1, object_sha1);
441 hashcpy(l->val_sha1, entry.sha1);
442 if (len < 20) {
443 if (!S_ISDIR(entry.mode) || path_len != 2)
444 goto handle_non_note; /* not subtree */
445 l->key_sha1[19] = (unsigned char) len;
446 type = PTR_TYPE_SUBTREE;
448 note_tree_insert(t, node, n, l, type,
449 combine_notes_concatenate);
451 continue;
453 handle_non_note:
455 * Determine full path for this non-note entry:
456 * The filename is already found in entry.path, but the
457 * directory part of the path must be deduced from the subtree
458 * containing this entry. We assume here that the overall notes
459 * tree follows a strict byte-based progressive fanout
460 * structure (i.e. using 2/38, 2/2/36, etc. fanouts, and not
461 * e.g. 4/36 fanout). This means that if a non-note is found at
462 * path "dead/beef", the following code will register it as
463 * being found on "de/ad/beef".
464 * On the other hand, if you use such non-obvious non-note
465 * paths in the middle of a notes tree, you deserve what's
466 * coming to you ;). Note that for non-notes that are not
467 * SHA1-like at the top level, there will be no problems.
469 * To conclude, it is strongly advised to make sure non-notes
470 * have at least one non-hex character in the top-level path
471 * component.
474 char non_note_path[PATH_MAX];
475 char *p = non_note_path;
476 const char *q = sha1_to_hex(subtree->key_sha1);
477 int i;
478 for (i = 0; i < prefix_len; i++) {
479 *p++ = *q++;
480 *p++ = *q++;
481 *p++ = '/';
483 strcpy(p, entry.path);
484 add_non_note(t, non_note_path, entry.mode, entry.sha1);
487 free(buf);
491 * Determine optimal on-disk fanout for this part of the notes tree
493 * Given a (sub)tree and the level in the internal tree structure, determine
494 * whether or not the given existing fanout should be expanded for this
495 * (sub)tree.
497 * Values of the 'fanout' variable:
498 * - 0: No fanout (all notes are stored directly in the root notes tree)
499 * - 1: 2/38 fanout
500 * - 2: 2/2/36 fanout
501 * - 3: 2/2/2/34 fanout
502 * etc.
504 static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
505 unsigned char fanout)
508 * The following is a simple heuristic that works well in practice:
509 * For each even-numbered 16-tree level (remember that each on-disk
510 * fanout level corresponds to _two_ 16-tree levels), peek at all 16
511 * entries at that tree level. If all of them are either int_nodes or
512 * subtree entries, then there are likely plenty of notes below this
513 * level, so we return an incremented fanout.
515 unsigned int i;
516 if ((n % 2) || (n > 2 * fanout))
517 return fanout;
518 for (i = 0; i < 16; i++) {
519 switch (GET_PTR_TYPE(tree->a[i])) {
520 case PTR_TYPE_SUBTREE:
521 case PTR_TYPE_INTERNAL:
522 continue;
523 default:
524 return fanout;
527 return fanout + 1;
530 static void construct_path_with_fanout(const unsigned char *sha1,
531 unsigned char fanout, char *path)
533 unsigned int i = 0, j = 0;
534 const char *hex_sha1 = sha1_to_hex(sha1);
535 assert(fanout < 20);
536 while (fanout) {
537 path[i++] = hex_sha1[j++];
538 path[i++] = hex_sha1[j++];
539 path[i++] = '/';
540 fanout--;
542 strcpy(path + i, hex_sha1 + j);
545 static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
546 unsigned char n, unsigned char fanout, int flags,
547 each_note_fn fn, void *cb_data)
549 unsigned int i;
550 void *p;
551 int ret = 0;
552 struct leaf_node *l;
553 static char path[40 + 19 + 1]; /* hex SHA1 + 19 * '/' + NUL */
555 fanout = determine_fanout(tree, n, fanout);
556 for (i = 0; i < 16; i++) {
557 redo:
558 p = tree->a[i];
559 switch (GET_PTR_TYPE(p)) {
560 case PTR_TYPE_INTERNAL:
561 /* recurse into int_node */
562 ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
563 fanout, flags, fn, cb_data);
564 break;
565 case PTR_TYPE_SUBTREE:
566 l = (struct leaf_node *) CLR_PTR_TYPE(p);
568 * Subtree entries in the note tree represent parts of
569 * the note tree that have not yet been explored. There
570 * is a direct relationship between subtree entries at
571 * level 'n' in the tree, and the 'fanout' variable:
572 * Subtree entries at level 'n <= 2 * fanout' should be
573 * preserved, since they correspond exactly to a fanout
574 * directory in the on-disk structure. However, subtree
575 * entries at level 'n > 2 * fanout' should NOT be
576 * preserved, but rather consolidated into the above
577 * notes tree level. We achieve this by unconditionally
578 * unpacking subtree entries that exist below the
579 * threshold level at 'n = 2 * fanout'.
581 if (n <= 2 * fanout &&
582 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
583 /* invoke callback with subtree */
584 unsigned int path_len =
585 l->key_sha1[19] * 2 + fanout;
586 assert(path_len < 40 + 19);
587 construct_path_with_fanout(l->key_sha1, fanout,
588 path);
589 /* Create trailing slash, if needed */
590 if (path[path_len - 1] != '/')
591 path[path_len++] = '/';
592 path[path_len] = '\0';
593 ret = fn(l->key_sha1, l->val_sha1, path,
594 cb_data);
596 if (n > fanout * 2 ||
597 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
598 /* unpack subtree and resume traversal */
599 tree->a[i] = NULL;
600 load_subtree(t, l, tree, n);
601 free(l);
602 goto redo;
604 break;
605 case PTR_TYPE_NOTE:
606 l = (struct leaf_node *) CLR_PTR_TYPE(p);
607 construct_path_with_fanout(l->key_sha1, fanout, path);
608 ret = fn(l->key_sha1, l->val_sha1, path, cb_data);
609 break;
611 if (ret)
612 return ret;
614 return 0;
617 struct tree_write_stack {
618 struct tree_write_stack *next;
619 struct strbuf buf;
620 char path[2]; /* path to subtree in next, if any */
623 static inline int matches_tree_write_stack(struct tree_write_stack *tws,
624 const char *full_path)
626 return full_path[0] == tws->path[0] &&
627 full_path[1] == tws->path[1] &&
628 full_path[2] == '/';
631 static void write_tree_entry(struct strbuf *buf, unsigned int mode,
632 const char *path, unsigned int path_len, const
633 unsigned char *sha1)
635 strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
636 strbuf_add(buf, sha1, 20);
639 static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
640 const char *path)
642 struct tree_write_stack *n;
643 assert(!tws->next);
644 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
645 n = (struct tree_write_stack *)
646 xmalloc(sizeof(struct tree_write_stack));
647 n->next = NULL;
648 strbuf_init(&n->buf, 256 * (32 + 40)); /* assume 256 entries per tree */
649 n->path[0] = n->path[1] = '\0';
650 tws->next = n;
651 tws->path[0] = path[0];
652 tws->path[1] = path[1];
655 static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
657 int ret;
658 struct tree_write_stack *n = tws->next;
659 unsigned char s[20];
660 if (n) {
661 ret = tree_write_stack_finish_subtree(n);
662 if (ret)
663 return ret;
664 ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s);
665 if (ret)
666 return ret;
667 strbuf_release(&n->buf);
668 free(n);
669 tws->next = NULL;
670 write_tree_entry(&tws->buf, 040000, tws->path, 2, s);
671 tws->path[0] = tws->path[1] = '\0';
673 return 0;
676 static int write_each_note_helper(struct tree_write_stack *tws,
677 const char *path, unsigned int mode,
678 const unsigned char *sha1)
680 size_t path_len = strlen(path);
681 unsigned int n = 0;
682 int ret;
684 /* Determine common part of tree write stack */
685 while (tws && 3 * n < path_len &&
686 matches_tree_write_stack(tws, path + 3 * n)) {
687 n++;
688 tws = tws->next;
691 /* tws point to last matching tree_write_stack entry */
692 ret = tree_write_stack_finish_subtree(tws);
693 if (ret)
694 return ret;
696 /* Start subtrees needed to satisfy path */
697 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
698 tree_write_stack_init_subtree(tws, path + 3 * n);
699 n++;
700 tws = tws->next;
703 /* There should be no more directory components in the given path */
704 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
706 /* Finally add given entry to the current tree object */
707 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
708 sha1);
710 return 0;
713 struct write_each_note_data {
714 struct tree_write_stack *root;
715 struct non_note *next_non_note;
718 static int write_each_non_note_until(const char *note_path,
719 struct write_each_note_data *d)
721 struct non_note *n = d->next_non_note;
722 int cmp = 0, ret;
723 while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
724 if (note_path && cmp == 0)
725 ; /* do nothing, prefer note to non-note */
726 else {
727 ret = write_each_note_helper(d->root, n->path, n->mode,
728 n->sha1);
729 if (ret)
730 return ret;
732 n = n->next;
734 d->next_non_note = n;
735 return 0;
738 static int write_each_note(const unsigned char *object_sha1,
739 const unsigned char *note_sha1, char *note_path,
740 void *cb_data)
742 struct write_each_note_data *d =
743 (struct write_each_note_data *) cb_data;
744 size_t note_path_len = strlen(note_path);
745 unsigned int mode = 0100644;
747 if (note_path[note_path_len - 1] == '/') {
748 /* subtree entry */
749 note_path_len--;
750 note_path[note_path_len] = '\0';
751 mode = 040000;
753 assert(note_path_len <= 40 + 19);
755 /* Weave non-note entries into note entries */
756 return write_each_non_note_until(note_path, d) ||
757 write_each_note_helper(d->root, note_path, mode, note_sha1);
760 struct note_delete_list {
761 struct note_delete_list *next;
762 const unsigned char *sha1;
765 static int prune_notes_helper(const unsigned char *object_sha1,
766 const unsigned char *note_sha1, char *note_path,
767 void *cb_data)
769 struct note_delete_list **l = (struct note_delete_list **) cb_data;
770 struct note_delete_list *n;
772 if (has_sha1_file(object_sha1))
773 return 0; /* nothing to do for this note */
775 /* failed to find object => prune this note */
776 n = (struct note_delete_list *) xmalloc(sizeof(*n));
777 n->next = *l;
778 n->sha1 = object_sha1;
779 *l = n;
780 return 0;
783 int combine_notes_concatenate(unsigned char *cur_sha1,
784 const unsigned char *new_sha1)
786 char *cur_msg = NULL, *new_msg = NULL, *buf;
787 unsigned long cur_len, new_len, buf_len;
788 enum object_type cur_type, new_type;
789 int ret;
791 /* read in both note blob objects */
792 if (!is_null_sha1(new_sha1))
793 new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
794 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
795 free(new_msg);
796 return 0;
798 if (!is_null_sha1(cur_sha1))
799 cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
800 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
801 free(cur_msg);
802 free(new_msg);
803 hashcpy(cur_sha1, new_sha1);
804 return 0;
807 /* we will separate the notes by a newline anyway */
808 if (cur_msg[cur_len - 1] == '\n')
809 cur_len--;
811 /* concatenate cur_msg and new_msg into buf */
812 buf_len = cur_len + 1 + new_len;
813 buf = (char *) xmalloc(buf_len);
814 memcpy(buf, cur_msg, cur_len);
815 buf[cur_len] = '\n';
816 memcpy(buf + cur_len + 1, new_msg, new_len);
817 free(cur_msg);
818 free(new_msg);
820 /* create a new blob object from buf */
821 ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
822 free(buf);
823 return ret;
826 int combine_notes_overwrite(unsigned char *cur_sha1,
827 const unsigned char *new_sha1)
829 hashcpy(cur_sha1, new_sha1);
830 return 0;
833 int combine_notes_ignore(unsigned char *cur_sha1,
834 const unsigned char *new_sha1)
836 return 0;
839 static int string_list_add_one_ref(const char *path, const unsigned char *sha1,
840 int flag, void *cb)
842 struct string_list *refs = cb;
843 if (!unsorted_string_list_has_string(refs, path))
844 string_list_append(refs, path);
845 return 0;
848 void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
850 if (has_glob_specials(glob)) {
851 for_each_glob_ref(string_list_add_one_ref, glob, list);
852 } else {
853 unsigned char sha1[20];
854 if (get_sha1(glob, sha1))
855 warning("notes ref %s is invalid", glob);
856 if (!unsorted_string_list_has_string(list, glob))
857 string_list_append(list, glob);
861 void string_list_add_refs_from_colon_sep(struct string_list *list,
862 const char *globs)
864 struct strbuf globbuf = STRBUF_INIT;
865 struct strbuf **split;
866 int i;
868 strbuf_addstr(&globbuf, globs);
869 split = strbuf_split(&globbuf, ':');
871 for (i = 0; split[i]; i++) {
872 if (!split[i]->len)
873 continue;
874 if (split[i]->buf[split[i]->len-1] == ':')
875 strbuf_setlen(split[i], split[i]->len-1);
876 string_list_add_refs_by_glob(list, split[i]->buf);
879 strbuf_list_free(split);
880 strbuf_release(&globbuf);
883 static int notes_display_config(const char *k, const char *v, void *cb)
885 int *load_refs = cb;
887 if (*load_refs && !strcmp(k, "notes.displayref")) {
888 if (!v)
889 config_error_nonbool(k);
890 string_list_add_refs_by_glob(&display_notes_refs, v);
893 return 0;
896 static const char *default_notes_ref(void)
898 const char *notes_ref = NULL;
899 if (!notes_ref)
900 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
901 if (!notes_ref)
902 notes_ref = notes_ref_name; /* value of core.notesRef config */
903 if (!notes_ref)
904 notes_ref = GIT_NOTES_DEFAULT_REF;
905 return notes_ref;
908 void init_notes(struct notes_tree *t, const char *notes_ref,
909 combine_notes_fn combine_notes, int flags)
911 unsigned char sha1[20], object_sha1[20];
912 unsigned mode;
913 struct leaf_node root_tree;
915 if (!t)
916 t = &default_notes_tree;
917 assert(!t->initialized);
919 if (!notes_ref)
920 notes_ref = default_notes_ref();
922 if (!combine_notes)
923 combine_notes = combine_notes_concatenate;
925 t->root = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
926 t->first_non_note = NULL;
927 t->prev_non_note = NULL;
928 t->ref = notes_ref ? xstrdup(notes_ref) : NULL;
929 t->combine_notes = combine_notes;
930 t->initialized = 1;
931 t->dirty = 0;
933 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
934 read_ref(notes_ref, object_sha1))
935 return;
936 if (get_tree_entry(object_sha1, "", sha1, &mode))
937 die("Failed to read notes tree referenced by %s (%s)",
938 notes_ref, object_sha1);
940 hashclr(root_tree.key_sha1);
941 hashcpy(root_tree.val_sha1, sha1);
942 load_subtree(t, &root_tree, t->root, 0);
945 struct notes_tree **load_notes_trees(struct string_list *refs)
947 struct string_list_item *item;
948 int counter = 0;
949 struct notes_tree **trees;
950 trees = xmalloc((refs->nr+1) * sizeof(struct notes_tree *));
951 for_each_string_list_item(item, refs) {
952 struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
953 init_notes(t, item->string, combine_notes_ignore, 0);
954 trees[counter++] = t;
956 trees[counter] = NULL;
957 return trees;
960 void init_display_notes(struct display_notes_opt *opt)
962 char *display_ref_env;
963 int load_config_refs = 0;
964 display_notes_refs.strdup_strings = 1;
966 assert(!display_notes_trees);
968 if (!opt || !opt->suppress_default_notes) {
969 string_list_append(&display_notes_refs, default_notes_ref());
970 display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
971 if (display_ref_env) {
972 string_list_add_refs_from_colon_sep(&display_notes_refs,
973 display_ref_env);
974 load_config_refs = 0;
975 } else
976 load_config_refs = 1;
979 git_config(notes_display_config, &load_config_refs);
981 if (opt && opt->extra_notes_refs) {
982 struct string_list_item *item;
983 for_each_string_list_item(item, opt->extra_notes_refs)
984 string_list_add_refs_by_glob(&display_notes_refs,
985 item->string);
988 display_notes_trees = load_notes_trees(&display_notes_refs);
989 string_list_clear(&display_notes_refs, 0);
992 void add_note(struct notes_tree *t, const unsigned char *object_sha1,
993 const unsigned char *note_sha1, combine_notes_fn combine_notes)
995 struct leaf_node *l;
997 if (!t)
998 t = &default_notes_tree;
999 assert(t->initialized);
1000 t->dirty = 1;
1001 if (!combine_notes)
1002 combine_notes = t->combine_notes;
1003 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
1004 hashcpy(l->key_sha1, object_sha1);
1005 hashcpy(l->val_sha1, note_sha1);
1006 note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
1009 int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1011 struct leaf_node l;
1013 if (!t)
1014 t = &default_notes_tree;
1015 assert(t->initialized);
1016 hashcpy(l.key_sha1, object_sha1);
1017 hashclr(l.val_sha1);
1018 note_tree_remove(t, t->root, 0, &l);
1019 if (is_null_sha1(l.val_sha1)) // no note was removed
1020 return 1;
1021 t->dirty = 1;
1022 return 0;
1025 const unsigned char *get_note(struct notes_tree *t,
1026 const unsigned char *object_sha1)
1028 struct leaf_node *found;
1030 if (!t)
1031 t = &default_notes_tree;
1032 assert(t->initialized);
1033 found = note_tree_find(t, t->root, 0, object_sha1);
1034 return found ? found->val_sha1 : NULL;
1037 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
1038 void *cb_data)
1040 if (!t)
1041 t = &default_notes_tree;
1042 assert(t->initialized);
1043 return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
1046 int write_notes_tree(struct notes_tree *t, unsigned char *result)
1048 struct tree_write_stack root;
1049 struct write_each_note_data cb_data;
1050 int ret;
1052 if (!t)
1053 t = &default_notes_tree;
1054 assert(t->initialized);
1056 /* Prepare for traversal of current notes tree */
1057 root.next = NULL; /* last forward entry in list is grounded */
1058 strbuf_init(&root.buf, 256 * (32 + 40)); /* assume 256 entries */
1059 root.path[0] = root.path[1] = '\0';
1060 cb_data.root = &root;
1061 cb_data.next_non_note = t->first_non_note;
1063 /* Write tree objects representing current notes tree */
1064 ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
1065 FOR_EACH_NOTE_YIELD_SUBTREES,
1066 write_each_note, &cb_data) ||
1067 write_each_non_note_until(NULL, &cb_data) ||
1068 tree_write_stack_finish_subtree(&root) ||
1069 write_sha1_file(root.buf.buf, root.buf.len, tree_type, result);
1070 strbuf_release(&root.buf);
1071 return ret;
1074 void prune_notes(struct notes_tree *t, int flags)
1076 struct note_delete_list *l = NULL;
1078 if (!t)
1079 t = &default_notes_tree;
1080 assert(t->initialized);
1082 for_each_note(t, 0, prune_notes_helper, &l);
1084 while (l) {
1085 if (flags & NOTES_PRUNE_VERBOSE)
1086 printf("%s\n", sha1_to_hex(l->sha1));
1087 if (!(flags & NOTES_PRUNE_DRYRUN))
1088 remove_note(t, l->sha1);
1089 l = l->next;
1093 void free_notes(struct notes_tree *t)
1095 if (!t)
1096 t = &default_notes_tree;
1097 if (t->root)
1098 note_tree_free(t->root);
1099 free(t->root);
1100 while (t->first_non_note) {
1101 t->prev_non_note = t->first_non_note->next;
1102 free(t->first_non_note->path);
1103 free(t->first_non_note);
1104 t->first_non_note = t->prev_non_note;
1106 free(t->ref);
1107 memset(t, 0, sizeof(struct notes_tree));
1110 void format_note(struct notes_tree *t, const unsigned char *object_sha1,
1111 struct strbuf *sb, const char *output_encoding, int flags)
1113 static const char utf8[] = "utf-8";
1114 const unsigned char *sha1;
1115 char *msg, *msg_p;
1116 unsigned long linelen, msglen;
1117 enum object_type type;
1119 if (!t)
1120 t = &default_notes_tree;
1121 if (!t->initialized)
1122 init_notes(t, NULL, NULL, 0);
1124 sha1 = get_note(t, object_sha1);
1125 if (!sha1)
1126 return;
1128 if (!(msg = read_sha1_file(sha1, &type, &msglen)) || !msglen ||
1129 type != OBJ_BLOB) {
1130 free(msg);
1131 return;
1134 if (output_encoding && *output_encoding &&
1135 strcmp(utf8, output_encoding)) {
1136 char *reencoded = reencode_string(msg, output_encoding, utf8);
1137 if (reencoded) {
1138 free(msg);
1139 msg = reencoded;
1140 msglen = strlen(msg);
1144 /* we will end the annotation by a newline anyway */
1145 if (msglen && msg[msglen - 1] == '\n')
1146 msglen--;
1148 if (flags & NOTES_SHOW_HEADER) {
1149 const char *ref = t->ref;
1150 if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
1151 strbuf_addstr(sb, "\nNotes:\n");
1152 } else {
1153 if (!prefixcmp(ref, "refs/"))
1154 ref += 5;
1155 if (!prefixcmp(ref, "notes/"))
1156 ref += 6;
1157 strbuf_addf(sb, "\nNotes (%s):\n", ref);
1161 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
1162 linelen = strchrnul(msg_p, '\n') - msg_p;
1164 if (flags & NOTES_INDENT)
1165 strbuf_addstr(sb, " ");
1166 strbuf_add(sb, msg_p, linelen);
1167 strbuf_addch(sb, '\n');
1170 free(msg);
1173 void format_display_notes(const unsigned char *object_sha1,
1174 struct strbuf *sb, const char *output_encoding, int flags)
1176 int i;
1177 assert(display_notes_trees);
1178 for (i = 0; display_notes_trees[i]; i++)
1179 format_note(display_notes_trees[i], object_sha1, sb,
1180 output_encoding, flags);
1183 int copy_note(struct notes_tree *t,
1184 const unsigned char *from_obj, const unsigned char *to_obj,
1185 int force, combine_notes_fn combine_fn)
1187 const unsigned char *note = get_note(t, from_obj);
1188 const unsigned char *existing_note = get_note(t, to_obj);
1190 if (!force && existing_note)
1191 return 1;
1193 if (note)
1194 add_note(t, to_obj, note, combine_fn);
1195 else if (existing_note)
1196 add_note(t, to_obj, null_sha1, combine_fn);
1198 return 0;