Merge branch 'ma/asciidoctor-more-fixes'
[git/git.git] / notes.c
1 #include "cache.h"
2 #include "config.h"
3 #include "notes.h"
4 #include "object-store.h"
5 #include "blob.h"
6 #include "tree.h"
7 #include "utf8.h"
8 #include "strbuf.h"
9 #include "tree-walk.h"
10 #include "string-list.h"
11 #include "refs.h"
12
13 /*
14 * Use a non-balancing simple 16-tree structure with struct int_node as
15 * internal nodes, and struct leaf_node as leaf nodes. Each int_node has a
16 * 16-array of pointers to its children.
17 * The bottom 2 bits of each pointer is used to identify the pointer type
18 * - ptr & 3 == 0 - NULL pointer, assert(ptr == NULL)
19 * - ptr & 3 == 1 - pointer to next internal node - cast to struct int_node *
20 * - ptr & 3 == 2 - pointer to note entry - cast to struct leaf_node *
21 * - ptr & 3 == 3 - pointer to subtree entry - cast to struct leaf_node *
22 *
23 * The root node is a statically allocated struct int_node.
24 */
25 struct int_node {
26 void *a[16];
27 };
28
29 /*
30 * Leaf nodes come in two variants, note entries and subtree entries,
31 * distinguished by the LSb of the leaf node pointer (see above).
32 * As a note entry, the key is the SHA1 of the referenced object, and the
33 * value is the SHA1 of the note object.
34 * As a subtree entry, the key is the prefix SHA1 (w/trailing NULs) of the
35 * referenced object, using the last byte of the key to store the length of
36 * the prefix. The value is the SHA1 of the tree object containing the notes
37 * subtree.
38 */
39 struct leaf_node {
40 struct object_id key_oid;
41 struct object_id val_oid;
42 };
43
44 /*
45 * A notes tree may contain entries that are not notes, and that do not follow
46 * the naming conventions of notes. There are typically none/few of these, but
47 * we still need to keep track of them. Keep a simple linked list sorted alpha-
48 * betically on the non-note path. The list is populated when parsing tree
49 * objects in load_subtree(), and the non-notes are correctly written back into
50 * the tree objects produced by write_notes_tree().
51 */
52 struct non_note {
53 struct non_note *next; /* grounded (last->next == NULL) */
54 char *path;
55 unsigned int mode;
56 struct object_id oid;
57 };
58
59 #define PTR_TYPE_NULL 0
60 #define PTR_TYPE_INTERNAL 1
61 #define PTR_TYPE_NOTE 2
62 #define PTR_TYPE_SUBTREE 3
63
64 #define GET_PTR_TYPE(ptr) ((uintptr_t) (ptr) & 3)
65 #define CLR_PTR_TYPE(ptr) ((void *) ((uintptr_t) (ptr) & ~3))
66 #define SET_PTR_TYPE(ptr, type) ((void *) ((uintptr_t) (ptr) | (type)))
67
68 #define GET_NIBBLE(n, sha1) ((((sha1)[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f)
69
70 #define KEY_INDEX (the_hash_algo->rawsz - 1)
71 #define FANOUT_PATH_SEPARATORS (the_hash_algo->rawsz - 1)
72 #define FANOUT_PATH_SEPARATORS_MAX ((GIT_MAX_HEXSZ / 2) - 1)
73 #define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
74 (memcmp(key_sha1, subtree_sha1, subtree_sha1[KEY_INDEX]))
75
76 struct notes_tree default_notes_tree;
77
78 static struct string_list display_notes_refs = STRING_LIST_INIT_NODUP;
79 static struct notes_tree **display_notes_trees;
80
81 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
82 struct int_node *node, unsigned int n);
83
84 /*
85 * Search the tree until the appropriate location for the given key is found:
86 * 1. Start at the root node, with n = 0
87 * 2. If a[0] at the current level is a matching subtree entry, unpack that
88 * subtree entry and remove it; restart search at the current level.
89 * 3. Use the nth nibble of the key as an index into a:
90 * - If a[n] is an int_node, recurse from #2 into that node and increment n
91 * - If a matching subtree entry, unpack that subtree entry (and remove it);
92 * restart search at the current level.
93 * - Otherwise, we have found one of the following:
94 * - a subtree entry which does not match the key
95 * - a note entry which may or may not match the key
96 * - an unused leaf node (NULL)
97 * In any case, set *tree and *n, and return pointer to the tree location.
98 */
99 static void **note_tree_search(struct notes_tree *t, struct int_node **tree,
100 unsigned char *n, const unsigned char *key_sha1)
101 {
102 struct leaf_node *l;
103 unsigned char i;
104 void *p = (*tree)->a[0];
105
106 if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) {
107 l = (struct leaf_node *) CLR_PTR_TYPE(p);
108 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_oid.hash)) {
109 /* unpack tree and resume search */
110 (*tree)->a[0] = NULL;
111 load_subtree(t, l, *tree, *n);
112 free(l);
113 return note_tree_search(t, tree, n, key_sha1);
114 }
115 }
116
117 i = GET_NIBBLE(*n, key_sha1);
118 p = (*tree)->a[i];
119 switch (GET_PTR_TYPE(p)) {
120 case PTR_TYPE_INTERNAL:
121 *tree = CLR_PTR_TYPE(p);
122 (*n)++;
123 return note_tree_search(t, tree, n, key_sha1);
124 case PTR_TYPE_SUBTREE:
125 l = (struct leaf_node *) CLR_PTR_TYPE(p);
126 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_oid.hash)) {
127 /* unpack tree and resume search */
128 (*tree)->a[i] = NULL;
129 load_subtree(t, l, *tree, *n);
130 free(l);
131 return note_tree_search(t, tree, n, key_sha1);
132 }
133 /* fall through */
134 default:
135 return &((*tree)->a[i]);
136 }
137 }
138
139 /*
140 * To find a leaf_node:
141 * Search to the tree location appropriate for the given key:
142 * If a note entry with matching key, return the note entry, else return NULL.
143 */
144 static struct leaf_node *note_tree_find(struct notes_tree *t,
145 struct int_node *tree, unsigned char n,
146 const unsigned char *key_sha1)
147 {
148 void **p = note_tree_search(t, &tree, &n, key_sha1);
149 if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) {
150 struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p);
151 if (hasheq(key_sha1, l->key_oid.hash))
152 return l;
153 }
154 return NULL;
155 }
156
157 /*
158 * How to consolidate an int_node:
159 * If there are > 1 non-NULL entries, give up and return non-zero.
160 * Otherwise replace the int_node at the given index in the given parent node
161 * with the only NOTE entry (or a NULL entry if no entries) from the given
162 * tree, and return 0.
163 */
164 static int note_tree_consolidate(struct int_node *tree,
165 struct int_node *parent, unsigned char index)
166 {
167 unsigned int i;
168 void *p = NULL;
169
170 assert(tree && parent);
171 assert(CLR_PTR_TYPE(parent->a[index]) == tree);
172
173 for (i = 0; i < 16; i++) {
174 if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) {
175 if (p) /* more than one entry */
176 return -2;
177 p = tree->a[i];
178 }
179 }
180
181 if (p && (GET_PTR_TYPE(p) != PTR_TYPE_NOTE))
182 return -2;
183 /* replace tree with p in parent[index] */
184 parent->a[index] = p;
185 free(tree);
186 return 0;
187 }
188
189 /*
190 * To remove a leaf_node:
191 * Search to the tree location appropriate for the given leaf_node's key:
192 * - If location does not hold a matching entry, abort and do nothing.
193 * - Copy the matching entry's value into the given entry.
194 * - Replace the matching leaf_node with a NULL entry (and free the leaf_node).
195 * - Consolidate int_nodes repeatedly, while walking up the tree towards root.
196 */
197 static void note_tree_remove(struct notes_tree *t,
198 struct int_node *tree, unsigned char n,
199 struct leaf_node *entry)
200 {
201 struct leaf_node *l;
202 struct int_node *parent_stack[GIT_MAX_RAWSZ];
203 unsigned char i, j;
204 void **p = note_tree_search(t, &tree, &n, entry->key_oid.hash);
205
206 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
207 if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
208 return; /* type mismatch, nothing to remove */
209 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
210 if (!oideq(&l->key_oid, &entry->key_oid))
211 return; /* key mismatch, nothing to remove */
212
213 /* we have found a matching entry */
214 oidcpy(&entry->val_oid, &l->val_oid);
215 free(l);
216 *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
217
218 /* consolidate this tree level, and parent levels, if possible */
219 if (!n)
220 return; /* cannot consolidate top level */
221 /* first, build stack of ancestors between root and current node */
222 parent_stack[0] = t->root;
223 for (i = 0; i < n; i++) {
224 j = GET_NIBBLE(i, entry->key_oid.hash);
225 parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]);
226 }
227 assert(i == n && parent_stack[i] == tree);
228 /* next, unwind stack until note_tree_consolidate() is done */
229 while (i > 0 &&
230 !note_tree_consolidate(parent_stack[i], parent_stack[i - 1],
231 GET_NIBBLE(i - 1, entry->key_oid.hash)))
232 i--;
233 }
234
235 /*
236 * To insert a leaf_node:
237 * Search to the tree location appropriate for the given leaf_node's key:
238 * - If location is unused (NULL), store the tweaked pointer directly there
239 * - If location holds a note entry that matches the note-to-be-inserted, then
240 * combine the two notes (by calling the given combine_notes function).
241 * - If location holds a note entry that matches the subtree-to-be-inserted,
242 * then unpack the subtree-to-be-inserted into the location.
243 * - If location holds a matching subtree entry, unpack the subtree at that
244 * location, and restart the insert operation from that level.
245 * - Else, create a new int_node, holding both the node-at-location and the
246 * node-to-be-inserted, and store the new int_node into the location.
247 */
248 static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
249 unsigned char n, struct leaf_node *entry, unsigned char type,
250 combine_notes_fn combine_notes)
251 {
252 struct int_node *new_node;
253 struct leaf_node *l;
254 void **p = note_tree_search(t, &tree, &n, entry->key_oid.hash);
255 int ret = 0;
256
257 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
258 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
259 switch (GET_PTR_TYPE(*p)) {
260 case PTR_TYPE_NULL:
261 assert(!*p);
262 if (is_null_oid(&entry->val_oid))
263 free(entry);
264 else
265 *p = SET_PTR_TYPE(entry, type);
266 return 0;
267 case PTR_TYPE_NOTE:
268 switch (type) {
269 case PTR_TYPE_NOTE:
270 if (oideq(&l->key_oid, &entry->key_oid)) {
271 /* skip concatenation if l == entry */
272 if (oideq(&l->val_oid, &entry->val_oid)) {
273 free(entry);
274 return 0;
275 }
276
277 ret = combine_notes(&l->val_oid,
278 &entry->val_oid);
279 if (!ret && is_null_oid(&l->val_oid))
280 note_tree_remove(t, tree, n, entry);
281 free(entry);
282 return ret;
283 }
284 break;
285 case PTR_TYPE_SUBTREE:
286 if (!SUBTREE_SHA1_PREFIXCMP(l->key_oid.hash,
287 entry->key_oid.hash)) {
288 /* unpack 'entry' */
289 load_subtree(t, entry, tree, n);
290 free(entry);
291 return 0;
292 }
293 break;
294 }
295 break;
296 case PTR_TYPE_SUBTREE:
297 if (!SUBTREE_SHA1_PREFIXCMP(entry->key_oid.hash, l->key_oid.hash)) {
298 /* unpack 'l' and restart insert */
299 *p = NULL;
300 load_subtree(t, l, tree, n);
301 free(l);
302 return note_tree_insert(t, tree, n, entry, type,
303 combine_notes);
304 }
305 break;
306 }
307
308 /* non-matching leaf_node */
309 assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
310 GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
311 if (is_null_oid(&entry->val_oid)) { /* skip insertion of empty note */
312 free(entry);
313 return 0;
314 }
315 new_node = (struct int_node *) xcalloc(1, sizeof(struct int_node));
316 ret = note_tree_insert(t, new_node, n + 1, l, GET_PTR_TYPE(*p),
317 combine_notes);
318 if (ret)
319 return ret;
320 *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
321 return note_tree_insert(t, new_node, n + 1, entry, type, combine_notes);
322 }
323
324 /* Free the entire notes data contained in the given tree */
325 static void note_tree_free(struct int_node *tree)
326 {
327 unsigned int i;
328 for (i = 0; i < 16; i++) {
329 void *p = tree->a[i];
330 switch (GET_PTR_TYPE(p)) {
331 case PTR_TYPE_INTERNAL:
332 note_tree_free(CLR_PTR_TYPE(p));
333 /* fall through */
334 case PTR_TYPE_NOTE:
335 case PTR_TYPE_SUBTREE:
336 free(CLR_PTR_TYPE(p));
337 }
338 }
339 }
340
341 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
342 {
343 return strcmp(a->path, b->path);
344 }
345
346 /* note: takes ownership of path string */
347 static void add_non_note(struct notes_tree *t, char *path,
348 unsigned int mode, const unsigned char *sha1)
349 {
350 struct non_note *p = t->prev_non_note, *n;
351 n = (struct non_note *) xmalloc(sizeof(struct non_note));
352 n->next = NULL;
353 n->path = path;
354 n->mode = mode;
355 hashcpy(n->oid.hash, sha1);
356 t->prev_non_note = n;
357
358 if (!t->first_non_note) {
359 t->first_non_note = n;
360 return;
361 }
362
363 if (non_note_cmp(p, n) < 0)
364 ; /* do nothing */
365 else if (non_note_cmp(t->first_non_note, n) <= 0)
366 p = t->first_non_note;
367 else {
368 /* n sorts before t->first_non_note */
369 n->next = t->first_non_note;
370 t->first_non_note = n;
371 return;
372 }
373
374 /* n sorts equal or after p */
375 while (p->next && non_note_cmp(p->next, n) <= 0)
376 p = p->next;
377
378 if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
379 assert(strcmp(p->path, n->path) == 0);
380 p->mode = n->mode;
381 oidcpy(&p->oid, &n->oid);
382 free(n);
383 t->prev_non_note = p;
384 return;
385 }
386
387 /* n sorts between p and p->next */
388 n->next = p->next;
389 p->next = n;
390 }
391
392 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
393 struct int_node *node, unsigned int n)
394 {
395 struct object_id object_oid;
396 size_t prefix_len;
397 void *buf;
398 struct tree_desc desc;
399 struct name_entry entry;
400 const unsigned hashsz = the_hash_algo->rawsz;
401
402 buf = fill_tree_descriptor(the_repository, &desc, &subtree->val_oid);
403 if (!buf)
404 die("Could not read %s for notes-index",
405 oid_to_hex(&subtree->val_oid));
406
407 prefix_len = subtree->key_oid.hash[KEY_INDEX];
408 if (prefix_len >= hashsz)
409 BUG("prefix_len (%"PRIuMAX") is out of range", (uintmax_t)prefix_len);
410 if (prefix_len * 2 < n)
411 BUG("prefix_len (%"PRIuMAX") is too small", (uintmax_t)prefix_len);
412 memcpy(object_oid.hash, subtree->key_oid.hash, prefix_len);
413 while (tree_entry(&desc, &entry)) {
414 unsigned char type;
415 struct leaf_node *l;
416 size_t path_len = strlen(entry.path);
417
418 if (path_len == 2 * (hashsz - prefix_len)) {
419 /* This is potentially the remainder of the SHA-1 */
420
421 if (!S_ISREG(entry.mode))
422 /* notes must be blobs */
423 goto handle_non_note;
424
425 if (hex_to_bytes(object_oid.hash + prefix_len, entry.path,
426 hashsz - prefix_len))
427 goto handle_non_note; /* entry.path is not a SHA1 */
428
429 type = PTR_TYPE_NOTE;
430 } else if (path_len == 2) {
431 /* This is potentially an internal node */
432 size_t len = prefix_len;
433
434 if (!S_ISDIR(entry.mode))
435 /* internal nodes must be trees */
436 goto handle_non_note;
437
438 if (hex_to_bytes(object_oid.hash + len++, entry.path, 1))
439 goto handle_non_note; /* entry.path is not a SHA1 */
440
441 /*
442 * Pad the rest of the SHA-1 with zeros,
443 * except for the last byte, where we write
444 * the length:
445 */
446 memset(object_oid.hash + len, 0, hashsz - len - 1);
447 object_oid.hash[KEY_INDEX] = (unsigned char)len;
448
449 type = PTR_TYPE_SUBTREE;
450 } else {
451 /* This can't be part of a note */
452 goto handle_non_note;
453 }
454
455 l = xcalloc(1, sizeof(*l));
456 oidcpy(&l->key_oid, &object_oid);
457 oidcpy(&l->val_oid, &entry.oid);
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 oid_to_hex(&object_oid), t->ref);
464
465 continue;
466
467 handle_non_note:
468 /*
469 * Determine full path for this non-note entry. The
470 * filename is already found in entry.path, but the
471 * directory part of the path must be deduced from the
472 * subtree containing this entry based on our
473 * knowledge that the overall notes tree follows a
474 * strict byte-based progressive fanout structure
475 * (i.e. using 2/38, 2/2/36, etc. fanouts).
476 */
477 {
478 struct strbuf non_note_path = STRBUF_INIT;
479 const char *q = oid_to_hex(&subtree->key_oid);
480 size_t i;
481 for (i = 0; i < prefix_len; i++) {
482 strbuf_addch(&non_note_path, *q++);
483 strbuf_addch(&non_note_path, *q++);
484 strbuf_addch(&non_note_path, '/');
485 }
486 strbuf_addstr(&non_note_path, entry.path);
487 add_non_note(t, strbuf_detach(&non_note_path, NULL),
488 entry.mode, entry.oid.hash);
489 }
490 }
491 free(buf);
492 }
493
494 /*
495 * Determine optimal on-disk fanout for this part of the notes tree
496 *
497 * Given a (sub)tree and the level in the internal tree structure, determine
498 * whether or not the given existing fanout should be expanded for this
499 * (sub)tree.
500 *
501 * Values of the 'fanout' variable:
502 * - 0: No fanout (all notes are stored directly in the root notes tree)
503 * - 1: 2/38 fanout
504 * - 2: 2/2/36 fanout
505 * - 3: 2/2/2/34 fanout
506 * etc.
507 */
508 static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
509 unsigned char fanout)
510 {
511 /*
512 * The following is a simple heuristic that works well in practice:
513 * For each even-numbered 16-tree level (remember that each on-disk
514 * fanout level corresponds to _two_ 16-tree levels), peek at all 16
515 * entries at that tree level. If all of them are either int_nodes or
516 * subtree entries, then there are likely plenty of notes below this
517 * level, so we return an incremented fanout.
518 */
519 unsigned int i;
520 if ((n % 2) || (n > 2 * fanout))
521 return fanout;
522 for (i = 0; i < 16; i++) {
523 switch (GET_PTR_TYPE(tree->a[i])) {
524 case PTR_TYPE_SUBTREE:
525 case PTR_TYPE_INTERNAL:
526 continue;
527 default:
528 return fanout;
529 }
530 }
531 return fanout + 1;
532 }
533
534 /* hex oid + '/' between each pair of hex digits + NUL */
535 #define FANOUT_PATH_MAX GIT_MAX_HEXSZ + FANOUT_PATH_SEPARATORS_MAX + 1
536
537 static void construct_path_with_fanout(const unsigned char *hash,
538 unsigned char fanout, char *path)
539 {
540 unsigned int i = 0, j = 0;
541 const char *hex_hash = hash_to_hex(hash);
542 assert(fanout < the_hash_algo->rawsz);
543 while (fanout) {
544 path[i++] = hex_hash[j++];
545 path[i++] = hex_hash[j++];
546 path[i++] = '/';
547 fanout--;
548 }
549 xsnprintf(path + i, FANOUT_PATH_MAX - i, "%s", hex_hash + j);
550 }
551
552 static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
553 unsigned char n, unsigned char fanout, int flags,
554 each_note_fn fn, void *cb_data)
555 {
556 unsigned int i;
557 void *p;
558 int ret = 0;
559 struct leaf_node *l;
560 static char path[FANOUT_PATH_MAX];
561
562 fanout = determine_fanout(tree, n, fanout);
563 for (i = 0; i < 16; i++) {
564 redo:
565 p = tree->a[i];
566 switch (GET_PTR_TYPE(p)) {
567 case PTR_TYPE_INTERNAL:
568 /* recurse into int_node */
569 ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
570 fanout, flags, fn, cb_data);
571 break;
572 case PTR_TYPE_SUBTREE:
573 l = (struct leaf_node *) CLR_PTR_TYPE(p);
574 /*
575 * Subtree entries in the note tree represent parts of
576 * the note tree that have not yet been explored. There
577 * is a direct relationship between subtree entries at
578 * level 'n' in the tree, and the 'fanout' variable:
579 * Subtree entries at level 'n <= 2 * fanout' should be
580 * preserved, since they correspond exactly to a fanout
581 * directory in the on-disk structure. However, subtree
582 * entries at level 'n > 2 * fanout' should NOT be
583 * preserved, but rather consolidated into the above
584 * notes tree level. We achieve this by unconditionally
585 * unpacking subtree entries that exist below the
586 * threshold level at 'n = 2 * fanout'.
587 */
588 if (n <= 2 * fanout &&
589 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
590 /* invoke callback with subtree */
591 unsigned int path_len =
592 l->key_oid.hash[KEY_INDEX] * 2 + fanout;
593 assert(path_len < FANOUT_PATH_MAX - 1);
594 construct_path_with_fanout(l->key_oid.hash,
595 fanout,
596 path);
597 /* Create trailing slash, if needed */
598 if (path[path_len - 1] != '/')
599 path[path_len++] = '/';
600 path[path_len] = '\0';
601 ret = fn(&l->key_oid, &l->val_oid,
602 path,
603 cb_data);
604 }
605 if (n > fanout * 2 ||
606 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
607 /* unpack subtree and resume traversal */
608 tree->a[i] = NULL;
609 load_subtree(t, l, tree, n);
610 free(l);
611 goto redo;
612 }
613 break;
614 case PTR_TYPE_NOTE:
615 l = (struct leaf_node *) CLR_PTR_TYPE(p);
616 construct_path_with_fanout(l->key_oid.hash, fanout,
617 path);
618 ret = fn(&l->key_oid, &l->val_oid, path,
619 cb_data);
620 break;
621 }
622 if (ret)
623 return ret;
624 }
625 return 0;
626 }
627
628 struct tree_write_stack {
629 struct tree_write_stack *next;
630 struct strbuf buf;
631 char path[2]; /* path to subtree in next, if any */
632 };
633
634 static inline int matches_tree_write_stack(struct tree_write_stack *tws,
635 const char *full_path)
636 {
637 return full_path[0] == tws->path[0] &&
638 full_path[1] == tws->path[1] &&
639 full_path[2] == '/';
640 }
641
642 static void write_tree_entry(struct strbuf *buf, unsigned int mode,
643 const char *path, unsigned int path_len, const
644 unsigned char *hash)
645 {
646 strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
647 strbuf_add(buf, hash, the_hash_algo->rawsz);
648 }
649
650 static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
651 const char *path)
652 {
653 struct tree_write_stack *n;
654 assert(!tws->next);
655 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
656 n = (struct tree_write_stack *)
657 xmalloc(sizeof(struct tree_write_stack));
658 n->next = NULL;
659 strbuf_init(&n->buf, 256 * (32 + the_hash_algo->hexsz)); /* assume 256 entries per tree */
660 n->path[0] = n->path[1] = '\0';
661 tws->next = n;
662 tws->path[0] = path[0];
663 tws->path[1] = path[1];
664 }
665
666 static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
667 {
668 int ret;
669 struct tree_write_stack *n = tws->next;
670 struct object_id s;
671 if (n) {
672 ret = tree_write_stack_finish_subtree(n);
673 if (ret)
674 return ret;
675 ret = write_object_file(n->buf.buf, n->buf.len, tree_type, &s);
676 if (ret)
677 return ret;
678 strbuf_release(&n->buf);
679 free(n);
680 tws->next = NULL;
681 write_tree_entry(&tws->buf, 040000, tws->path, 2, s.hash);
682 tws->path[0] = tws->path[1] = '\0';
683 }
684 return 0;
685 }
686
687 static int write_each_note_helper(struct tree_write_stack *tws,
688 const char *path, unsigned int mode,
689 const struct object_id *oid)
690 {
691 size_t path_len = strlen(path);
692 unsigned int n = 0;
693 int ret;
694
695 /* Determine common part of tree write stack */
696 while (tws && 3 * n < path_len &&
697 matches_tree_write_stack(tws, path + 3 * n)) {
698 n++;
699 tws = tws->next;
700 }
701
702 /* tws point to last matching tree_write_stack entry */
703 ret = tree_write_stack_finish_subtree(tws);
704 if (ret)
705 return ret;
706
707 /* Start subtrees needed to satisfy path */
708 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
709 tree_write_stack_init_subtree(tws, path + 3 * n);
710 n++;
711 tws = tws->next;
712 }
713
714 /* There should be no more directory components in the given path */
715 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
716
717 /* Finally add given entry to the current tree object */
718 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
719 oid->hash);
720
721 return 0;
722 }
723
724 struct write_each_note_data {
725 struct tree_write_stack *root;
726 struct non_note *next_non_note;
727 };
728
729 static int write_each_non_note_until(const char *note_path,
730 struct write_each_note_data *d)
731 {
732 struct non_note *n = d->next_non_note;
733 int cmp = 0, ret;
734 while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
735 if (note_path && cmp == 0)
736 ; /* do nothing, prefer note to non-note */
737 else {
738 ret = write_each_note_helper(d->root, n->path, n->mode,
739 &n->oid);
740 if (ret)
741 return ret;
742 }
743 n = n->next;
744 }
745 d->next_non_note = n;
746 return 0;
747 }
748
749 static int write_each_note(const struct object_id *object_oid,
750 const struct object_id *note_oid, char *note_path,
751 void *cb_data)
752 {
753 struct write_each_note_data *d =
754 (struct write_each_note_data *) cb_data;
755 size_t note_path_len = strlen(note_path);
756 unsigned int mode = 0100644;
757
758 if (note_path[note_path_len - 1] == '/') {
759 /* subtree entry */
760 note_path_len--;
761 note_path[note_path_len] = '\0';
762 mode = 040000;
763 }
764 assert(note_path_len <= GIT_MAX_HEXSZ + FANOUT_PATH_SEPARATORS);
765
766 /* Weave non-note entries into note entries */
767 return write_each_non_note_until(note_path, d) ||
768 write_each_note_helper(d->root, note_path, mode, note_oid);
769 }
770
771 struct note_delete_list {
772 struct note_delete_list *next;
773 const unsigned char *sha1;
774 };
775
776 static int prune_notes_helper(const struct object_id *object_oid,
777 const struct object_id *note_oid, char *note_path,
778 void *cb_data)
779 {
780 struct note_delete_list **l = (struct note_delete_list **) cb_data;
781 struct note_delete_list *n;
782
783 if (has_object_file(object_oid))
784 return 0; /* nothing to do for this note */
785
786 /* failed to find object => prune this note */
787 n = (struct note_delete_list *) xmalloc(sizeof(*n));
788 n->next = *l;
789 n->sha1 = object_oid->hash;
790 *l = n;
791 return 0;
792 }
793
794 int combine_notes_concatenate(struct object_id *cur_oid,
795 const struct object_id *new_oid)
796 {
797 char *cur_msg = NULL, *new_msg = NULL, *buf;
798 unsigned long cur_len, new_len, buf_len;
799 enum object_type cur_type, new_type;
800 int ret;
801
802 /* read in both note blob objects */
803 if (!is_null_oid(new_oid))
804 new_msg = read_object_file(new_oid, &new_type, &new_len);
805 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
806 free(new_msg);
807 return 0;
808 }
809 if (!is_null_oid(cur_oid))
810 cur_msg = read_object_file(cur_oid, &cur_type, &cur_len);
811 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
812 free(cur_msg);
813 free(new_msg);
814 oidcpy(cur_oid, new_oid);
815 return 0;
816 }
817
818 /* we will separate the notes by two newlines anyway */
819 if (cur_msg[cur_len - 1] == '\n')
820 cur_len--;
821
822 /* concatenate cur_msg and new_msg into buf */
823 buf_len = cur_len + 2 + new_len;
824 buf = (char *) xmalloc(buf_len);
825 memcpy(buf, cur_msg, cur_len);
826 buf[cur_len] = '\n';
827 buf[cur_len + 1] = '\n';
828 memcpy(buf + cur_len + 2, new_msg, new_len);
829 free(cur_msg);
830 free(new_msg);
831
832 /* create a new blob object from buf */
833 ret = write_object_file(buf, buf_len, blob_type, cur_oid);
834 free(buf);
835 return ret;
836 }
837
838 int combine_notes_overwrite(struct object_id *cur_oid,
839 const struct object_id *new_oid)
840 {
841 oidcpy(cur_oid, new_oid);
842 return 0;
843 }
844
845 int combine_notes_ignore(struct object_id *cur_oid,
846 const struct object_id *new_oid)
847 {
848 return 0;
849 }
850
851 /*
852 * Add the lines from the named object to list, with trailing
853 * newlines removed.
854 */
855 static int string_list_add_note_lines(struct string_list *list,
856 const struct object_id *oid)
857 {
858 char *data;
859 unsigned long len;
860 enum object_type t;
861
862 if (is_null_oid(oid))
863 return 0;
864
865 /* read_sha1_file NUL-terminates */
866 data = read_object_file(oid, &t, &len);
867 if (t != OBJ_BLOB || !data || !len) {
868 free(data);
869 return t != OBJ_BLOB || !data;
870 }
871
872 /*
873 * If the last line of the file is EOL-terminated, this will
874 * add an empty string to the list. But it will be removed
875 * later, along with any empty strings that came from empty
876 * lines within the file.
877 */
878 string_list_split(list, data, '\n', -1);
879 free(data);
880 return 0;
881 }
882
883 static int string_list_join_lines_helper(struct string_list_item *item,
884 void *cb_data)
885 {
886 struct strbuf *buf = cb_data;
887 strbuf_addstr(buf, item->string);
888 strbuf_addch(buf, '\n');
889 return 0;
890 }
891
892 int combine_notes_cat_sort_uniq(struct object_id *cur_oid,
893 const struct object_id *new_oid)
894 {
895 struct string_list sort_uniq_list = STRING_LIST_INIT_DUP;
896 struct strbuf buf = STRBUF_INIT;
897 int ret = 1;
898
899 /* read both note blob objects into unique_lines */
900 if (string_list_add_note_lines(&sort_uniq_list, cur_oid))
901 goto out;
902 if (string_list_add_note_lines(&sort_uniq_list, new_oid))
903 goto out;
904 string_list_remove_empty_items(&sort_uniq_list, 0);
905 string_list_sort(&sort_uniq_list);
906 string_list_remove_duplicates(&sort_uniq_list, 0);
907
908 /* create a new blob object from sort_uniq_list */
909 if (for_each_string_list(&sort_uniq_list,
910 string_list_join_lines_helper, &buf))
911 goto out;
912
913 ret = write_object_file(buf.buf, buf.len, blob_type, cur_oid);
914
915 out:
916 strbuf_release(&buf);
917 string_list_clear(&sort_uniq_list, 0);
918 return ret;
919 }
920
921 static int string_list_add_one_ref(const char *refname, const struct object_id *oid,
922 int flag, void *cb)
923 {
924 struct string_list *refs = cb;
925 if (!unsorted_string_list_has_string(refs, refname))
926 string_list_append(refs, refname);
927 return 0;
928 }
929
930 /*
931 * The list argument must have strdup_strings set on it.
932 */
933 void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
934 {
935 assert(list->strdup_strings);
936 if (has_glob_specials(glob)) {
937 for_each_glob_ref(string_list_add_one_ref, glob, list);
938 } else {
939 struct object_id oid;
940 if (get_oid(glob, &oid))
941 warning("notes ref %s is invalid", glob);
942 if (!unsorted_string_list_has_string(list, glob))
943 string_list_append(list, glob);
944 }
945 }
946
947 void string_list_add_refs_from_colon_sep(struct string_list *list,
948 const char *globs)
949 {
950 struct string_list split = STRING_LIST_INIT_NODUP;
951 char *globs_copy = xstrdup(globs);
952 int i;
953
954 string_list_split_in_place(&split, globs_copy, ':', -1);
955 string_list_remove_empty_items(&split, 0);
956
957 for (i = 0; i < split.nr; i++)
958 string_list_add_refs_by_glob(list, split.items[i].string);
959
960 string_list_clear(&split, 0);
961 free(globs_copy);
962 }
963
964 static int notes_display_config(const char *k, const char *v, void *cb)
965 {
966 int *load_refs = cb;
967
968 if (*load_refs && !strcmp(k, "notes.displayref")) {
969 if (!v)
970 config_error_nonbool(k);
971 string_list_add_refs_by_glob(&display_notes_refs, v);
972 }
973
974 return 0;
975 }
976
977 const char *default_notes_ref(void)
978 {
979 const char *notes_ref = NULL;
980 if (!notes_ref)
981 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
982 if (!notes_ref)
983 notes_ref = notes_ref_name; /* value of core.notesRef config */
984 if (!notes_ref)
985 notes_ref = GIT_NOTES_DEFAULT_REF;
986 return notes_ref;
987 }
988
989 void init_notes(struct notes_tree *t, const char *notes_ref,
990 combine_notes_fn combine_notes, int flags)
991 {
992 struct object_id oid, object_oid;
993 unsigned short mode;
994 struct leaf_node root_tree;
995
996 if (!t)
997 t = &default_notes_tree;
998 assert(!t->initialized);
999
1000 if (!notes_ref)
1001 notes_ref = default_notes_ref();
1002
1003 if (!combine_notes)
1004 combine_notes = combine_notes_concatenate;
1005
1006 t->root = (struct int_node *) xcalloc(1, sizeof(struct int_node));
1007 t->first_non_note = NULL;
1008 t->prev_non_note = NULL;
1009 t->ref = xstrdup_or_null(notes_ref);
1010 t->update_ref = (flags & NOTES_INIT_WRITABLE) ? t->ref : NULL;
1011 t->combine_notes = combine_notes;
1012 t->initialized = 1;
1013 t->dirty = 0;
1014
1015 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
1016 get_oid_treeish(notes_ref, &object_oid))
1017 return;
1018 if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, &object_oid))
1019 die("Cannot use notes ref %s", notes_ref);
1020 if (get_tree_entry(the_repository, &object_oid, "", &oid, &mode))
1021 die("Failed to read notes tree referenced by %s (%s)",
1022 notes_ref, oid_to_hex(&object_oid));
1023
1024 oidclr(&root_tree.key_oid);
1025 oidcpy(&root_tree.val_oid, &oid);
1026 load_subtree(t, &root_tree, t->root, 0);
1027 }
1028
1029 struct notes_tree **load_notes_trees(struct string_list *refs, int flags)
1030 {
1031 struct string_list_item *item;
1032 int counter = 0;
1033 struct notes_tree **trees;
1034 ALLOC_ARRAY(trees, refs->nr + 1);
1035 for_each_string_list_item(item, refs) {
1036 struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
1037 init_notes(t, item->string, combine_notes_ignore, flags);
1038 trees[counter++] = t;
1039 }
1040 trees[counter] = NULL;
1041 return trees;
1042 }
1043
1044 void init_display_notes(struct display_notes_opt *opt)
1045 {
1046 char *display_ref_env;
1047 int load_config_refs = 0;
1048 display_notes_refs.strdup_strings = 1;
1049
1050 assert(!display_notes_trees);
1051
1052 if (!opt || opt->use_default_notes > 0 ||
1053 (opt->use_default_notes == -1 && !opt->extra_notes_refs.nr)) {
1054 string_list_append(&display_notes_refs, default_notes_ref());
1055 display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
1056 if (display_ref_env) {
1057 string_list_add_refs_from_colon_sep(&display_notes_refs,
1058 display_ref_env);
1059 load_config_refs = 0;
1060 } else
1061 load_config_refs = 1;
1062 }
1063
1064 git_config(notes_display_config, &load_config_refs);
1065
1066 if (opt) {
1067 struct string_list_item *item;
1068 for_each_string_list_item(item, &opt->extra_notes_refs)
1069 string_list_add_refs_by_glob(&display_notes_refs,
1070 item->string);
1071 }
1072
1073 display_notes_trees = load_notes_trees(&display_notes_refs, 0);
1074 string_list_clear(&display_notes_refs, 0);
1075 }
1076
1077 int add_note(struct notes_tree *t, const struct object_id *object_oid,
1078 const struct object_id *note_oid, combine_notes_fn combine_notes)
1079 {
1080 struct leaf_node *l;
1081
1082 if (!t)
1083 t = &default_notes_tree;
1084 assert(t->initialized);
1085 t->dirty = 1;
1086 if (!combine_notes)
1087 combine_notes = t->combine_notes;
1088 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
1089 oidcpy(&l->key_oid, object_oid);
1090 oidcpy(&l->val_oid, note_oid);
1091 return note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
1092 }
1093
1094 int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1095 {
1096 struct leaf_node l;
1097
1098 if (!t)
1099 t = &default_notes_tree;
1100 assert(t->initialized);
1101 hashcpy(l.key_oid.hash, object_sha1);
1102 oidclr(&l.val_oid);
1103 note_tree_remove(t, t->root, 0, &l);
1104 if (is_null_oid(&l.val_oid)) /* no note was removed */
1105 return 1;
1106 t->dirty = 1;
1107 return 0;
1108 }
1109
1110 const struct object_id *get_note(struct notes_tree *t,
1111 const struct object_id *oid)
1112 {
1113 struct leaf_node *found;
1114
1115 if (!t)
1116 t = &default_notes_tree;
1117 assert(t->initialized);
1118 found = note_tree_find(t, t->root, 0, oid->hash);
1119 return found ? &found->val_oid : NULL;
1120 }
1121
1122 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
1123 void *cb_data)
1124 {
1125 if (!t)
1126 t = &default_notes_tree;
1127 assert(t->initialized);
1128 return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
1129 }
1130
1131 int write_notes_tree(struct notes_tree *t, struct object_id *result)
1132 {
1133 struct tree_write_stack root;
1134 struct write_each_note_data cb_data;
1135 int ret;
1136 int flags;
1137
1138 if (!t)
1139 t = &default_notes_tree;
1140 assert(t->initialized);
1141
1142 /* Prepare for traversal of current notes tree */
1143 root.next = NULL; /* last forward entry in list is grounded */
1144 strbuf_init(&root.buf, 256 * (32 + the_hash_algo->hexsz)); /* assume 256 entries */
1145 root.path[0] = root.path[1] = '\0';
1146 cb_data.root = &root;
1147 cb_data.next_non_note = t->first_non_note;
1148
1149 /* Write tree objects representing current notes tree */
1150 flags = FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
1151 FOR_EACH_NOTE_YIELD_SUBTREES;
1152 ret = for_each_note(t, flags, write_each_note, &cb_data) ||
1153 write_each_non_note_until(NULL, &cb_data) ||
1154 tree_write_stack_finish_subtree(&root) ||
1155 write_object_file(root.buf.buf, root.buf.len, tree_type, result);
1156 strbuf_release(&root.buf);
1157 return ret;
1158 }
1159
1160 void prune_notes(struct notes_tree *t, int flags)
1161 {
1162 struct note_delete_list *l = NULL;
1163
1164 if (!t)
1165 t = &default_notes_tree;
1166 assert(t->initialized);
1167
1168 for_each_note(t, 0, prune_notes_helper, &l);
1169
1170 while (l) {
1171 if (flags & NOTES_PRUNE_VERBOSE)
1172 printf("%s\n", hash_to_hex(l->sha1));
1173 if (!(flags & NOTES_PRUNE_DRYRUN))
1174 remove_note(t, l->sha1);
1175 l = l->next;
1176 }
1177 }
1178
1179 void free_notes(struct notes_tree *t)
1180 {
1181 if (!t)
1182 t = &default_notes_tree;
1183 if (t->root)
1184 note_tree_free(t->root);
1185 free(t->root);
1186 while (t->first_non_note) {
1187 t->prev_non_note = t->first_non_note->next;
1188 free(t->first_non_note->path);
1189 free(t->first_non_note);
1190 t->first_non_note = t->prev_non_note;
1191 }
1192 free(t->ref);
1193 memset(t, 0, sizeof(struct notes_tree));
1194 }
1195
1196 /*
1197 * Fill the given strbuf with the notes associated with the given object.
1198 *
1199 * If the given notes_tree structure is not initialized, it will be auto-
1200 * initialized to the default value (see documentation for init_notes() above).
1201 * If the given notes_tree is NULL, the internal/default notes_tree will be
1202 * used instead.
1203 *
1204 * (raw != 0) gives the %N userformat; otherwise, the note message is given
1205 * for human consumption.
1206 */
1207 static void format_note(struct notes_tree *t, const struct object_id *object_oid,
1208 struct strbuf *sb, const char *output_encoding, int raw)
1209 {
1210 static const char utf8[] = "utf-8";
1211 const struct object_id *oid;
1212 char *msg, *msg_p;
1213 unsigned long linelen, msglen;
1214 enum object_type type;
1215
1216 if (!t)
1217 t = &default_notes_tree;
1218 if (!t->initialized)
1219 init_notes(t, NULL, NULL, 0);
1220
1221 oid = get_note(t, object_oid);
1222 if (!oid)
1223 return;
1224
1225 if (!(msg = read_object_file(oid, &type, &msglen)) || type != OBJ_BLOB) {
1226 free(msg);
1227 return;
1228 }
1229
1230 if (output_encoding && *output_encoding &&
1231 !is_encoding_utf8(output_encoding)) {
1232 char *reencoded = reencode_string(msg, output_encoding, utf8);
1233 if (reencoded) {
1234 free(msg);
1235 msg = reencoded;
1236 msglen = strlen(msg);
1237 }
1238 }
1239
1240 /* we will end the annotation by a newline anyway */
1241 if (msglen && msg[msglen - 1] == '\n')
1242 msglen--;
1243
1244 if (!raw) {
1245 const char *ref = t->ref;
1246 if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
1247 strbuf_addstr(sb, "\nNotes:\n");
1248 } else {
1249 if (starts_with(ref, "refs/"))
1250 ref += 5;
1251 if (starts_with(ref, "notes/"))
1252 ref += 6;
1253 strbuf_addf(sb, "\nNotes (%s):\n", ref);
1254 }
1255 }
1256
1257 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
1258 linelen = strchrnul(msg_p, '\n') - msg_p;
1259
1260 if (!raw)
1261 strbuf_addstr(sb, " ");
1262 strbuf_add(sb, msg_p, linelen);
1263 strbuf_addch(sb, '\n');
1264 }
1265
1266 free(msg);
1267 }
1268
1269 void format_display_notes(const struct object_id *object_oid,
1270 struct strbuf *sb, const char *output_encoding, int raw)
1271 {
1272 int i;
1273 assert(display_notes_trees);
1274 for (i = 0; display_notes_trees[i]; i++)
1275 format_note(display_notes_trees[i], object_oid, sb,
1276 output_encoding, raw);
1277 }
1278
1279 int copy_note(struct notes_tree *t,
1280 const struct object_id *from_obj, const struct object_id *to_obj,
1281 int force, combine_notes_fn combine_notes)
1282 {
1283 const struct object_id *note = get_note(t, from_obj);
1284 const struct object_id *existing_note = get_note(t, to_obj);
1285
1286 if (!force && existing_note)
1287 return 1;
1288
1289 if (note)
1290 return add_note(t, to_obj, note, combine_notes);
1291 else if (existing_note)
1292 return add_note(t, to_obj, &null_oid, combine_notes);
1293
1294 return 0;
1295 }
1296
1297 void expand_notes_ref(struct strbuf *sb)
1298 {
1299 if (starts_with(sb->buf, "refs/notes/"))
1300 return; /* we're happy */
1301 else if (starts_with(sb->buf, "notes/"))
1302 strbuf_insert(sb, 0, "refs/", 5);
1303 else
1304 strbuf_insert(sb, 0, "refs/notes/", 11);
1305 }
1306
1307 void expand_loose_notes_ref(struct strbuf *sb)
1308 {
1309 struct object_id object;
1310
1311 if (get_oid(sb->buf, &object)) {
1312 /* fallback to expand_notes_ref */
1313 expand_notes_ref(sb);
1314 }
1315 }