Merge branch 'rs/strbuf-detach'
[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 return 0;
274
275 ret = combine_notes(&l->val_oid,
276 &entry->val_oid);
277 if (!ret && is_null_oid(&l->val_oid))
278 note_tree_remove(t, tree, n, entry);
279 free(entry);
280 return ret;
281 }
282 break;
283 case PTR_TYPE_SUBTREE:
284 if (!SUBTREE_SHA1_PREFIXCMP(l->key_oid.hash,
285 entry->key_oid.hash)) {
286 /* unpack 'entry' */
287 load_subtree(t, entry, tree, n);
288 free(entry);
289 return 0;
290 }
291 break;
292 }
293 break;
294 case PTR_TYPE_SUBTREE:
295 if (!SUBTREE_SHA1_PREFIXCMP(entry->key_oid.hash, l->key_oid.hash)) {
296 /* unpack 'l' and restart insert */
297 *p = NULL;
298 load_subtree(t, l, tree, n);
299 free(l);
300 return note_tree_insert(t, tree, n, entry, type,
301 combine_notes);
302 }
303 break;
304 }
305
306 /* non-matching leaf_node */
307 assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
308 GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
309 if (is_null_oid(&entry->val_oid)) { /* skip insertion of empty note */
310 free(entry);
311 return 0;
312 }
313 new_node = (struct int_node *) xcalloc(1, sizeof(struct int_node));
314 ret = note_tree_insert(t, new_node, n + 1, l, GET_PTR_TYPE(*p),
315 combine_notes);
316 if (ret)
317 return ret;
318 *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
319 return note_tree_insert(t, new_node, n + 1, entry, type, combine_notes);
320 }
321
322 /* Free the entire notes data contained in the given tree */
323 static void note_tree_free(struct int_node *tree)
324 {
325 unsigned int i;
326 for (i = 0; i < 16; i++) {
327 void *p = tree->a[i];
328 switch (GET_PTR_TYPE(p)) {
329 case PTR_TYPE_INTERNAL:
330 note_tree_free(CLR_PTR_TYPE(p));
331 /* fall through */
332 case PTR_TYPE_NOTE:
333 case PTR_TYPE_SUBTREE:
334 free(CLR_PTR_TYPE(p));
335 }
336 }
337 }
338
339 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
340 {
341 return strcmp(a->path, b->path);
342 }
343
344 /* note: takes ownership of path string */
345 static void add_non_note(struct notes_tree *t, char *path,
346 unsigned int mode, const unsigned char *sha1)
347 {
348 struct non_note *p = t->prev_non_note, *n;
349 n = (struct non_note *) xmalloc(sizeof(struct non_note));
350 n->next = NULL;
351 n->path = path;
352 n->mode = mode;
353 hashcpy(n->oid.hash, sha1);
354 t->prev_non_note = n;
355
356 if (!t->first_non_note) {
357 t->first_non_note = n;
358 return;
359 }
360
361 if (non_note_cmp(p, n) < 0)
362 ; /* do nothing */
363 else if (non_note_cmp(t->first_non_note, n) <= 0)
364 p = t->first_non_note;
365 else {
366 /* n sorts before t->first_non_note */
367 n->next = t->first_non_note;
368 t->first_non_note = n;
369 return;
370 }
371
372 /* n sorts equal or after p */
373 while (p->next && non_note_cmp(p->next, n) <= 0)
374 p = p->next;
375
376 if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
377 assert(strcmp(p->path, n->path) == 0);
378 p->mode = n->mode;
379 oidcpy(&p->oid, &n->oid);
380 free(n);
381 t->prev_non_note = p;
382 return;
383 }
384
385 /* n sorts between p and p->next */
386 n->next = p->next;
387 p->next = n;
388 }
389
390 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
391 struct int_node *node, unsigned int n)
392 {
393 struct object_id object_oid;
394 size_t prefix_len;
395 void *buf;
396 struct tree_desc desc;
397 struct name_entry entry;
398 const unsigned hashsz = the_hash_algo->rawsz;
399
400 buf = fill_tree_descriptor(the_repository, &desc, &subtree->val_oid);
401 if (!buf)
402 die("Could not read %s for notes-index",
403 oid_to_hex(&subtree->val_oid));
404
405 prefix_len = subtree->key_oid.hash[KEY_INDEX];
406 if (prefix_len >= hashsz)
407 BUG("prefix_len (%"PRIuMAX") is out of range", (uintmax_t)prefix_len);
408 if (prefix_len * 2 < n)
409 BUG("prefix_len (%"PRIuMAX") is too small", (uintmax_t)prefix_len);
410 memcpy(object_oid.hash, subtree->key_oid.hash, prefix_len);
411 while (tree_entry(&desc, &entry)) {
412 unsigned char type;
413 struct leaf_node *l;
414 size_t path_len = strlen(entry.path);
415
416 if (path_len == 2 * (hashsz - prefix_len)) {
417 /* This is potentially the remainder of the SHA-1 */
418
419 if (!S_ISREG(entry.mode))
420 /* notes must be blobs */
421 goto handle_non_note;
422
423 if (hex_to_bytes(object_oid.hash + prefix_len, entry.path,
424 hashsz - prefix_len))
425 goto handle_non_note; /* entry.path is not a SHA1 */
426
427 type = PTR_TYPE_NOTE;
428 } else if (path_len == 2) {
429 /* This is potentially an internal node */
430 size_t len = prefix_len;
431
432 if (!S_ISDIR(entry.mode))
433 /* internal nodes must be trees */
434 goto handle_non_note;
435
436 if (hex_to_bytes(object_oid.hash + len++, entry.path, 1))
437 goto handle_non_note; /* entry.path is not a SHA1 */
438
439 /*
440 * Pad the rest of the SHA-1 with zeros,
441 * except for the last byte, where we write
442 * the length:
443 */
444 memset(object_oid.hash + len, 0, hashsz - len - 1);
445 object_oid.hash[KEY_INDEX] = (unsigned char)len;
446
447 type = PTR_TYPE_SUBTREE;
448 } else {
449 /* This can't be part of a note */
450 goto handle_non_note;
451 }
452
453 l = xcalloc(1, sizeof(*l));
454 oidcpy(&l->key_oid, &object_oid);
455 oidcpy(&l->val_oid, &entry.oid);
456 if (note_tree_insert(t, node, n, l, type,
457 combine_notes_concatenate))
458 die("Failed to load %s %s into notes tree "
459 "from %s",
460 type == PTR_TYPE_NOTE ? "note" : "subtree",
461 oid_to_hex(&l->key_oid), t->ref);
462
463 continue;
464
465 handle_non_note:
466 /*
467 * Determine full path for this non-note entry. The
468 * filename is already found in entry.path, but the
469 * directory part of the path must be deduced from the
470 * subtree containing this entry based on our
471 * knowledge that the overall notes tree follows a
472 * strict byte-based progressive fanout structure
473 * (i.e. using 2/38, 2/2/36, etc. fanouts).
474 */
475 {
476 struct strbuf non_note_path = STRBUF_INIT;
477 const char *q = oid_to_hex(&subtree->key_oid);
478 size_t i;
479 for (i = 0; i < prefix_len; i++) {
480 strbuf_addch(&non_note_path, *q++);
481 strbuf_addch(&non_note_path, *q++);
482 strbuf_addch(&non_note_path, '/');
483 }
484 strbuf_addstr(&non_note_path, entry.path);
485 add_non_note(t, strbuf_detach(&non_note_path, NULL),
486 entry.mode, entry.oid.hash);
487 }
488 }
489 free(buf);
490 }
491
492 /*
493 * Determine optimal on-disk fanout for this part of the notes tree
494 *
495 * Given a (sub)tree and the level in the internal tree structure, determine
496 * whether or not the given existing fanout should be expanded for this
497 * (sub)tree.
498 *
499 * Values of the 'fanout' variable:
500 * - 0: No fanout (all notes are stored directly in the root notes tree)
501 * - 1: 2/38 fanout
502 * - 2: 2/2/36 fanout
503 * - 3: 2/2/2/34 fanout
504 * etc.
505 */
506 static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
507 unsigned char fanout)
508 {
509 /*
510 * The following is a simple heuristic that works well in practice:
511 * For each even-numbered 16-tree level (remember that each on-disk
512 * fanout level corresponds to _two_ 16-tree levels), peek at all 16
513 * entries at that tree level. If all of them are either int_nodes or
514 * subtree entries, then there are likely plenty of notes below this
515 * level, so we return an incremented fanout.
516 */
517 unsigned int i;
518 if ((n % 2) || (n > 2 * fanout))
519 return fanout;
520 for (i = 0; i < 16; i++) {
521 switch (GET_PTR_TYPE(tree->a[i])) {
522 case PTR_TYPE_SUBTREE:
523 case PTR_TYPE_INTERNAL:
524 continue;
525 default:
526 return fanout;
527 }
528 }
529 return fanout + 1;
530 }
531
532 /* hex oid + '/' between each pair of hex digits + NUL */
533 #define FANOUT_PATH_MAX GIT_MAX_HEXSZ + FANOUT_PATH_SEPARATORS_MAX + 1
534
535 static void construct_path_with_fanout(const unsigned char *hash,
536 unsigned char fanout, char *path)
537 {
538 unsigned int i = 0, j = 0;
539 const char *hex_hash = hash_to_hex(hash);
540 assert(fanout < the_hash_algo->rawsz);
541 while (fanout) {
542 path[i++] = hex_hash[j++];
543 path[i++] = hex_hash[j++];
544 path[i++] = '/';
545 fanout--;
546 }
547 xsnprintf(path + i, FANOUT_PATH_MAX - i, "%s", hex_hash + j);
548 }
549
550 static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
551 unsigned char n, unsigned char fanout, int flags,
552 each_note_fn fn, void *cb_data)
553 {
554 unsigned int i;
555 void *p;
556 int ret = 0;
557 struct leaf_node *l;
558 static char path[FANOUT_PATH_MAX];
559
560 fanout = determine_fanout(tree, n, fanout);
561 for (i = 0; i < 16; i++) {
562 redo:
563 p = tree->a[i];
564 switch (GET_PTR_TYPE(p)) {
565 case PTR_TYPE_INTERNAL:
566 /* recurse into int_node */
567 ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
568 fanout, flags, fn, cb_data);
569 break;
570 case PTR_TYPE_SUBTREE:
571 l = (struct leaf_node *) CLR_PTR_TYPE(p);
572 /*
573 * Subtree entries in the note tree represent parts of
574 * the note tree that have not yet been explored. There
575 * is a direct relationship between subtree entries at
576 * level 'n' in the tree, and the 'fanout' variable:
577 * Subtree entries at level 'n <= 2 * fanout' should be
578 * preserved, since they correspond exactly to a fanout
579 * directory in the on-disk structure. However, subtree
580 * entries at level 'n > 2 * fanout' should NOT be
581 * preserved, but rather consolidated into the above
582 * notes tree level. We achieve this by unconditionally
583 * unpacking subtree entries that exist below the
584 * threshold level at 'n = 2 * fanout'.
585 */
586 if (n <= 2 * fanout &&
587 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
588 /* invoke callback with subtree */
589 unsigned int path_len =
590 l->key_oid.hash[KEY_INDEX] * 2 + fanout;
591 assert(path_len < FANOUT_PATH_MAX - 1);
592 construct_path_with_fanout(l->key_oid.hash,
593 fanout,
594 path);
595 /* Create trailing slash, if needed */
596 if (path[path_len - 1] != '/')
597 path[path_len++] = '/';
598 path[path_len] = '\0';
599 ret = fn(&l->key_oid, &l->val_oid,
600 path,
601 cb_data);
602 }
603 if (n > fanout * 2 ||
604 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
605 /* unpack subtree and resume traversal */
606 tree->a[i] = NULL;
607 load_subtree(t, l, tree, n);
608 free(l);
609 goto redo;
610 }
611 break;
612 case PTR_TYPE_NOTE:
613 l = (struct leaf_node *) CLR_PTR_TYPE(p);
614 construct_path_with_fanout(l->key_oid.hash, fanout,
615 path);
616 ret = fn(&l->key_oid, &l->val_oid, path,
617 cb_data);
618 break;
619 }
620 if (ret)
621 return ret;
622 }
623 return 0;
624 }
625
626 struct tree_write_stack {
627 struct tree_write_stack *next;
628 struct strbuf buf;
629 char path[2]; /* path to subtree in next, if any */
630 };
631
632 static inline int matches_tree_write_stack(struct tree_write_stack *tws,
633 const char *full_path)
634 {
635 return full_path[0] == tws->path[0] &&
636 full_path[1] == tws->path[1] &&
637 full_path[2] == '/';
638 }
639
640 static void write_tree_entry(struct strbuf *buf, unsigned int mode,
641 const char *path, unsigned int path_len, const
642 unsigned char *hash)
643 {
644 strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
645 strbuf_add(buf, hash, the_hash_algo->rawsz);
646 }
647
648 static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
649 const char *path)
650 {
651 struct tree_write_stack *n;
652 assert(!tws->next);
653 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
654 n = (struct tree_write_stack *)
655 xmalloc(sizeof(struct tree_write_stack));
656 n->next = NULL;
657 strbuf_init(&n->buf, 256 * (32 + the_hash_algo->hexsz)); /* assume 256 entries per tree */
658 n->path[0] = n->path[1] = '\0';
659 tws->next = n;
660 tws->path[0] = path[0];
661 tws->path[1] = path[1];
662 }
663
664 static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
665 {
666 int ret;
667 struct tree_write_stack *n = tws->next;
668 struct object_id s;
669 if (n) {
670 ret = tree_write_stack_finish_subtree(n);
671 if (ret)
672 return ret;
673 ret = write_object_file(n->buf.buf, n->buf.len, tree_type, &s);
674 if (ret)
675 return ret;
676 strbuf_release(&n->buf);
677 free(n);
678 tws->next = NULL;
679 write_tree_entry(&tws->buf, 040000, tws->path, 2, s.hash);
680 tws->path[0] = tws->path[1] = '\0';
681 }
682 return 0;
683 }
684
685 static int write_each_note_helper(struct tree_write_stack *tws,
686 const char *path, unsigned int mode,
687 const struct object_id *oid)
688 {
689 size_t path_len = strlen(path);
690 unsigned int n = 0;
691 int ret;
692
693 /* Determine common part of tree write stack */
694 while (tws && 3 * n < path_len &&
695 matches_tree_write_stack(tws, path + 3 * n)) {
696 n++;
697 tws = tws->next;
698 }
699
700 /* tws point to last matching tree_write_stack entry */
701 ret = tree_write_stack_finish_subtree(tws);
702 if (ret)
703 return ret;
704
705 /* Start subtrees needed to satisfy path */
706 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
707 tree_write_stack_init_subtree(tws, path + 3 * n);
708 n++;
709 tws = tws->next;
710 }
711
712 /* There should be no more directory components in the given path */
713 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
714
715 /* Finally add given entry to the current tree object */
716 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
717 oid->hash);
718
719 return 0;
720 }
721
722 struct write_each_note_data {
723 struct tree_write_stack *root;
724 struct non_note *next_non_note;
725 };
726
727 static int write_each_non_note_until(const char *note_path,
728 struct write_each_note_data *d)
729 {
730 struct non_note *n = d->next_non_note;
731 int cmp = 0, ret;
732 while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
733 if (note_path && cmp == 0)
734 ; /* do nothing, prefer note to non-note */
735 else {
736 ret = write_each_note_helper(d->root, n->path, n->mode,
737 &n->oid);
738 if (ret)
739 return ret;
740 }
741 n = n->next;
742 }
743 d->next_non_note = n;
744 return 0;
745 }
746
747 static int write_each_note(const struct object_id *object_oid,
748 const struct object_id *note_oid, char *note_path,
749 void *cb_data)
750 {
751 struct write_each_note_data *d =
752 (struct write_each_note_data *) cb_data;
753 size_t note_path_len = strlen(note_path);
754 unsigned int mode = 0100644;
755
756 if (note_path[note_path_len - 1] == '/') {
757 /* subtree entry */
758 note_path_len--;
759 note_path[note_path_len] = '\0';
760 mode = 040000;
761 }
762 assert(note_path_len <= GIT_MAX_HEXSZ + FANOUT_PATH_SEPARATORS);
763
764 /* Weave non-note entries into note entries */
765 return write_each_non_note_until(note_path, d) ||
766 write_each_note_helper(d->root, note_path, mode, note_oid);
767 }
768
769 struct note_delete_list {
770 struct note_delete_list *next;
771 const unsigned char *sha1;
772 };
773
774 static int prune_notes_helper(const struct object_id *object_oid,
775 const struct object_id *note_oid, char *note_path,
776 void *cb_data)
777 {
778 struct note_delete_list **l = (struct note_delete_list **) cb_data;
779 struct note_delete_list *n;
780
781 if (has_object_file(object_oid))
782 return 0; /* nothing to do for this note */
783
784 /* failed to find object => prune this note */
785 n = (struct note_delete_list *) xmalloc(sizeof(*n));
786 n->next = *l;
787 n->sha1 = object_oid->hash;
788 *l = n;
789 return 0;
790 }
791
792 int combine_notes_concatenate(struct object_id *cur_oid,
793 const struct object_id *new_oid)
794 {
795 char *cur_msg = NULL, *new_msg = NULL, *buf;
796 unsigned long cur_len, new_len, buf_len;
797 enum object_type cur_type, new_type;
798 int ret;
799
800 /* read in both note blob objects */
801 if (!is_null_oid(new_oid))
802 new_msg = read_object_file(new_oid, &new_type, &new_len);
803 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
804 free(new_msg);
805 return 0;
806 }
807 if (!is_null_oid(cur_oid))
808 cur_msg = read_object_file(cur_oid, &cur_type, &cur_len);
809 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
810 free(cur_msg);
811 free(new_msg);
812 oidcpy(cur_oid, new_oid);
813 return 0;
814 }
815
816 /* we will separate the notes by two newlines anyway */
817 if (cur_msg[cur_len - 1] == '\n')
818 cur_len--;
819
820 /* concatenate cur_msg and new_msg into buf */
821 buf_len = cur_len + 2 + new_len;
822 buf = (char *) xmalloc(buf_len);
823 memcpy(buf, cur_msg, cur_len);
824 buf[cur_len] = '\n';
825 buf[cur_len + 1] = '\n';
826 memcpy(buf + cur_len + 2, new_msg, new_len);
827 free(cur_msg);
828 free(new_msg);
829
830 /* create a new blob object from buf */
831 ret = write_object_file(buf, buf_len, blob_type, cur_oid);
832 free(buf);
833 return ret;
834 }
835
836 int combine_notes_overwrite(struct object_id *cur_oid,
837 const struct object_id *new_oid)
838 {
839 oidcpy(cur_oid, new_oid);
840 return 0;
841 }
842
843 int combine_notes_ignore(struct object_id *cur_oid,
844 const struct object_id *new_oid)
845 {
846 return 0;
847 }
848
849 /*
850 * Add the lines from the named object to list, with trailing
851 * newlines removed.
852 */
853 static int string_list_add_note_lines(struct string_list *list,
854 const struct object_id *oid)
855 {
856 char *data;
857 unsigned long len;
858 enum object_type t;
859
860 if (is_null_oid(oid))
861 return 0;
862
863 /* read_sha1_file NUL-terminates */
864 data = read_object_file(oid, &t, &len);
865 if (t != OBJ_BLOB || !data || !len) {
866 free(data);
867 return t != OBJ_BLOB || !data;
868 }
869
870 /*
871 * If the last line of the file is EOL-terminated, this will
872 * add an empty string to the list. But it will be removed
873 * later, along with any empty strings that came from empty
874 * lines within the file.
875 */
876 string_list_split(list, data, '\n', -1);
877 free(data);
878 return 0;
879 }
880
881 static int string_list_join_lines_helper(struct string_list_item *item,
882 void *cb_data)
883 {
884 struct strbuf *buf = cb_data;
885 strbuf_addstr(buf, item->string);
886 strbuf_addch(buf, '\n');
887 return 0;
888 }
889
890 int combine_notes_cat_sort_uniq(struct object_id *cur_oid,
891 const struct object_id *new_oid)
892 {
893 struct string_list sort_uniq_list = STRING_LIST_INIT_DUP;
894 struct strbuf buf = STRBUF_INIT;
895 int ret = 1;
896
897 /* read both note blob objects into unique_lines */
898 if (string_list_add_note_lines(&sort_uniq_list, cur_oid))
899 goto out;
900 if (string_list_add_note_lines(&sort_uniq_list, new_oid))
901 goto out;
902 string_list_remove_empty_items(&sort_uniq_list, 0);
903 string_list_sort(&sort_uniq_list);
904 string_list_remove_duplicates(&sort_uniq_list, 0);
905
906 /* create a new blob object from sort_uniq_list */
907 if (for_each_string_list(&sort_uniq_list,
908 string_list_join_lines_helper, &buf))
909 goto out;
910
911 ret = write_object_file(buf.buf, buf.len, blob_type, cur_oid);
912
913 out:
914 strbuf_release(&buf);
915 string_list_clear(&sort_uniq_list, 0);
916 return ret;
917 }
918
919 static int string_list_add_one_ref(const char *refname, const struct object_id *oid,
920 int flag, void *cb)
921 {
922 struct string_list *refs = cb;
923 if (!unsorted_string_list_has_string(refs, refname))
924 string_list_append(refs, refname);
925 return 0;
926 }
927
928 /*
929 * The list argument must have strdup_strings set on it.
930 */
931 void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
932 {
933 assert(list->strdup_strings);
934 if (has_glob_specials(glob)) {
935 for_each_glob_ref(string_list_add_one_ref, glob, list);
936 } else {
937 struct object_id oid;
938 if (get_oid(glob, &oid))
939 warning("notes ref %s is invalid", glob);
940 if (!unsorted_string_list_has_string(list, glob))
941 string_list_append(list, glob);
942 }
943 }
944
945 void string_list_add_refs_from_colon_sep(struct string_list *list,
946 const char *globs)
947 {
948 struct string_list split = STRING_LIST_INIT_NODUP;
949 char *globs_copy = xstrdup(globs);
950 int i;
951
952 string_list_split_in_place(&split, globs_copy, ':', -1);
953 string_list_remove_empty_items(&split, 0);
954
955 for (i = 0; i < split.nr; i++)
956 string_list_add_refs_by_glob(list, split.items[i].string);
957
958 string_list_clear(&split, 0);
959 free(globs_copy);
960 }
961
962 static int notes_display_config(const char *k, const char *v, void *cb)
963 {
964 int *load_refs = cb;
965
966 if (*load_refs && !strcmp(k, "notes.displayref")) {
967 if (!v)
968 config_error_nonbool(k);
969 string_list_add_refs_by_glob(&display_notes_refs, v);
970 }
971
972 return 0;
973 }
974
975 const char *default_notes_ref(void)
976 {
977 const char *notes_ref = NULL;
978 if (!notes_ref)
979 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
980 if (!notes_ref)
981 notes_ref = notes_ref_name; /* value of core.notesRef config */
982 if (!notes_ref)
983 notes_ref = GIT_NOTES_DEFAULT_REF;
984 return notes_ref;
985 }
986
987 void init_notes(struct notes_tree *t, const char *notes_ref,
988 combine_notes_fn combine_notes, int flags)
989 {
990 struct object_id oid, object_oid;
991 unsigned short mode;
992 struct leaf_node root_tree;
993
994 if (!t)
995 t = &default_notes_tree;
996 assert(!t->initialized);
997
998 if (!notes_ref)
999 notes_ref = default_notes_ref();
1000
1001 if (!combine_notes)
1002 combine_notes = combine_notes_concatenate;
1003
1004 t->root = (struct int_node *) xcalloc(1, sizeof(struct int_node));
1005 t->first_non_note = NULL;
1006 t->prev_non_note = NULL;
1007 t->ref = xstrdup_or_null(notes_ref);
1008 t->update_ref = (flags & NOTES_INIT_WRITABLE) ? t->ref : NULL;
1009 t->combine_notes = combine_notes;
1010 t->initialized = 1;
1011 t->dirty = 0;
1012
1013 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
1014 get_oid_treeish(notes_ref, &object_oid))
1015 return;
1016 if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, &object_oid))
1017 die("Cannot use notes ref %s", notes_ref);
1018 if (get_tree_entry(the_repository, &object_oid, "", &oid, &mode))
1019 die("Failed to read notes tree referenced by %s (%s)",
1020 notes_ref, oid_to_hex(&object_oid));
1021
1022 oidclr(&root_tree.key_oid);
1023 oidcpy(&root_tree.val_oid, &oid);
1024 load_subtree(t, &root_tree, t->root, 0);
1025 }
1026
1027 struct notes_tree **load_notes_trees(struct string_list *refs, int flags)
1028 {
1029 struct string_list_item *item;
1030 int counter = 0;
1031 struct notes_tree **trees;
1032 ALLOC_ARRAY(trees, refs->nr + 1);
1033 for_each_string_list_item(item, refs) {
1034 struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
1035 init_notes(t, item->string, combine_notes_ignore, flags);
1036 trees[counter++] = t;
1037 }
1038 trees[counter] = NULL;
1039 return trees;
1040 }
1041
1042 void init_display_notes(struct display_notes_opt *opt)
1043 {
1044 char *display_ref_env;
1045 int load_config_refs = 0;
1046 display_notes_refs.strdup_strings = 1;
1047
1048 assert(!display_notes_trees);
1049
1050 if (!opt || opt->use_default_notes > 0 ||
1051 (opt->use_default_notes == -1 && !opt->extra_notes_refs.nr)) {
1052 string_list_append(&display_notes_refs, default_notes_ref());
1053 display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
1054 if (display_ref_env) {
1055 string_list_add_refs_from_colon_sep(&display_notes_refs,
1056 display_ref_env);
1057 load_config_refs = 0;
1058 } else
1059 load_config_refs = 1;
1060 }
1061
1062 git_config(notes_display_config, &load_config_refs);
1063
1064 if (opt) {
1065 struct string_list_item *item;
1066 for_each_string_list_item(item, &opt->extra_notes_refs)
1067 string_list_add_refs_by_glob(&display_notes_refs,
1068 item->string);
1069 }
1070
1071 display_notes_trees = load_notes_trees(&display_notes_refs, 0);
1072 string_list_clear(&display_notes_refs, 0);
1073 }
1074
1075 int add_note(struct notes_tree *t, const struct object_id *object_oid,
1076 const struct object_id *note_oid, combine_notes_fn combine_notes)
1077 {
1078 struct leaf_node *l;
1079
1080 if (!t)
1081 t = &default_notes_tree;
1082 assert(t->initialized);
1083 t->dirty = 1;
1084 if (!combine_notes)
1085 combine_notes = t->combine_notes;
1086 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
1087 oidcpy(&l->key_oid, object_oid);
1088 oidcpy(&l->val_oid, note_oid);
1089 return note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
1090 }
1091
1092 int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1093 {
1094 struct leaf_node l;
1095
1096 if (!t)
1097 t = &default_notes_tree;
1098 assert(t->initialized);
1099 hashcpy(l.key_oid.hash, object_sha1);
1100 oidclr(&l.val_oid);
1101 note_tree_remove(t, t->root, 0, &l);
1102 if (is_null_oid(&l.val_oid)) /* no note was removed */
1103 return 1;
1104 t->dirty = 1;
1105 return 0;
1106 }
1107
1108 const struct object_id *get_note(struct notes_tree *t,
1109 const struct object_id *oid)
1110 {
1111 struct leaf_node *found;
1112
1113 if (!t)
1114 t = &default_notes_tree;
1115 assert(t->initialized);
1116 found = note_tree_find(t, t->root, 0, oid->hash);
1117 return found ? &found->val_oid : NULL;
1118 }
1119
1120 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
1121 void *cb_data)
1122 {
1123 if (!t)
1124 t = &default_notes_tree;
1125 assert(t->initialized);
1126 return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
1127 }
1128
1129 int write_notes_tree(struct notes_tree *t, struct object_id *result)
1130 {
1131 struct tree_write_stack root;
1132 struct write_each_note_data cb_data;
1133 int ret;
1134 int flags;
1135
1136 if (!t)
1137 t = &default_notes_tree;
1138 assert(t->initialized);
1139
1140 /* Prepare for traversal of current notes tree */
1141 root.next = NULL; /* last forward entry in list is grounded */
1142 strbuf_init(&root.buf, 256 * (32 + the_hash_algo->hexsz)); /* assume 256 entries */
1143 root.path[0] = root.path[1] = '\0';
1144 cb_data.root = &root;
1145 cb_data.next_non_note = t->first_non_note;
1146
1147 /* Write tree objects representing current notes tree */
1148 flags = FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
1149 FOR_EACH_NOTE_YIELD_SUBTREES;
1150 ret = for_each_note(t, flags, write_each_note, &cb_data) ||
1151 write_each_non_note_until(NULL, &cb_data) ||
1152 tree_write_stack_finish_subtree(&root) ||
1153 write_object_file(root.buf.buf, root.buf.len, tree_type, result);
1154 strbuf_release(&root.buf);
1155 return ret;
1156 }
1157
1158 void prune_notes(struct notes_tree *t, int flags)
1159 {
1160 struct note_delete_list *l = NULL;
1161
1162 if (!t)
1163 t = &default_notes_tree;
1164 assert(t->initialized);
1165
1166 for_each_note(t, 0, prune_notes_helper, &l);
1167
1168 while (l) {
1169 if (flags & NOTES_PRUNE_VERBOSE)
1170 printf("%s\n", hash_to_hex(l->sha1));
1171 if (!(flags & NOTES_PRUNE_DRYRUN))
1172 remove_note(t, l->sha1);
1173 l = l->next;
1174 }
1175 }
1176
1177 void free_notes(struct notes_tree *t)
1178 {
1179 if (!t)
1180 t = &default_notes_tree;
1181 if (t->root)
1182 note_tree_free(t->root);
1183 free(t->root);
1184 while (t->first_non_note) {
1185 t->prev_non_note = t->first_non_note->next;
1186 free(t->first_non_note->path);
1187 free(t->first_non_note);
1188 t->first_non_note = t->prev_non_note;
1189 }
1190 free(t->ref);
1191 memset(t, 0, sizeof(struct notes_tree));
1192 }
1193
1194 /*
1195 * Fill the given strbuf with the notes associated with the given object.
1196 *
1197 * If the given notes_tree structure is not initialized, it will be auto-
1198 * initialized to the default value (see documentation for init_notes() above).
1199 * If the given notes_tree is NULL, the internal/default notes_tree will be
1200 * used instead.
1201 *
1202 * (raw != 0) gives the %N userformat; otherwise, the note message is given
1203 * for human consumption.
1204 */
1205 static void format_note(struct notes_tree *t, const struct object_id *object_oid,
1206 struct strbuf *sb, const char *output_encoding, int raw)
1207 {
1208 static const char utf8[] = "utf-8";
1209 const struct object_id *oid;
1210 char *msg, *msg_p;
1211 unsigned long linelen, msglen;
1212 enum object_type type;
1213
1214 if (!t)
1215 t = &default_notes_tree;
1216 if (!t->initialized)
1217 init_notes(t, NULL, NULL, 0);
1218
1219 oid = get_note(t, object_oid);
1220 if (!oid)
1221 return;
1222
1223 if (!(msg = read_object_file(oid, &type, &msglen)) || type != OBJ_BLOB) {
1224 free(msg);
1225 return;
1226 }
1227
1228 if (output_encoding && *output_encoding &&
1229 !is_encoding_utf8(output_encoding)) {
1230 char *reencoded = reencode_string(msg, output_encoding, utf8);
1231 if (reencoded) {
1232 free(msg);
1233 msg = reencoded;
1234 msglen = strlen(msg);
1235 }
1236 }
1237
1238 /* we will end the annotation by a newline anyway */
1239 if (msglen && msg[msglen - 1] == '\n')
1240 msglen--;
1241
1242 if (!raw) {
1243 const char *ref = t->ref;
1244 if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
1245 strbuf_addstr(sb, "\nNotes:\n");
1246 } else {
1247 if (starts_with(ref, "refs/"))
1248 ref += 5;
1249 if (starts_with(ref, "notes/"))
1250 ref += 6;
1251 strbuf_addf(sb, "\nNotes (%s):\n", ref);
1252 }
1253 }
1254
1255 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
1256 linelen = strchrnul(msg_p, '\n') - msg_p;
1257
1258 if (!raw)
1259 strbuf_addstr(sb, " ");
1260 strbuf_add(sb, msg_p, linelen);
1261 strbuf_addch(sb, '\n');
1262 }
1263
1264 free(msg);
1265 }
1266
1267 void format_display_notes(const struct object_id *object_oid,
1268 struct strbuf *sb, const char *output_encoding, int raw)
1269 {
1270 int i;
1271 assert(display_notes_trees);
1272 for (i = 0; display_notes_trees[i]; i++)
1273 format_note(display_notes_trees[i], object_oid, sb,
1274 output_encoding, raw);
1275 }
1276
1277 int copy_note(struct notes_tree *t,
1278 const struct object_id *from_obj, const struct object_id *to_obj,
1279 int force, combine_notes_fn combine_notes)
1280 {
1281 const struct object_id *note = get_note(t, from_obj);
1282 const struct object_id *existing_note = get_note(t, to_obj);
1283
1284 if (!force && existing_note)
1285 return 1;
1286
1287 if (note)
1288 return add_note(t, to_obj, note, combine_notes);
1289 else if (existing_note)
1290 return add_note(t, to_obj, &null_oid, combine_notes);
1291
1292 return 0;
1293 }
1294
1295 void expand_notes_ref(struct strbuf *sb)
1296 {
1297 if (starts_with(sb->buf, "refs/notes/"))
1298 return; /* we're happy */
1299 else if (starts_with(sb->buf, "notes/"))
1300 strbuf_insert(sb, 0, "refs/", 5);
1301 else
1302 strbuf_insert(sb, 0, "refs/notes/", 11);
1303 }
1304
1305 void expand_loose_notes_ref(struct strbuf *sb)
1306 {
1307 struct object_id object;
1308
1309 if (get_oid(sb->buf, &object)) {
1310 /* fallback to expand_notes_ref */
1311 expand_notes_ref(sb);
1312 }
1313 }