archive.c: avoid access to the_index
[git.git] / notes.c
blob32d3dbcc1e74ce344da89b9aa2b9ca09f6e62d2b
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"
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 *
23 * The root node is a statically allocated struct int_node.
25 struct int_node {
26 void *a[16];
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.
39 struct leaf_node {
40 struct object_id key_oid;
41 struct object_id val_oid;
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().
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;
59 #define PTR_TYPE_NULL 0
60 #define PTR_TYPE_INTERNAL 1
61 #define PTR_TYPE_NOTE 2
62 #define PTR_TYPE_SUBTREE 3
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)))
68 #define GET_NIBBLE(n, sha1) ((((sha1)[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f)
70 #define KEY_INDEX (GIT_SHA1_RAWSZ - 1)
71 #define FANOUT_PATH_SEPARATORS ((GIT_SHA1_HEXSZ / 2) - 1)
72 #define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
73 (memcmp(key_sha1, subtree_sha1, subtree_sha1[KEY_INDEX]))
75 struct notes_tree default_notes_tree;
77 static struct string_list display_notes_refs = STRING_LIST_INIT_NODUP;
78 static struct notes_tree **display_notes_trees;
80 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
81 struct int_node *node, unsigned int n);
84 * Search the tree until the appropriate location for the given key is found:
85 * 1. Start at the root node, with n = 0
86 * 2. If a[0] at the current level is a matching subtree entry, unpack that
87 * subtree entry and remove it; restart search at the current level.
88 * 3. Use the nth nibble of the key as an index into a:
89 * - If a[n] is an int_node, recurse from #2 into that node and increment n
90 * - If a matching subtree entry, unpack that subtree entry (and remove it);
91 * restart search at the current level.
92 * - Otherwise, we have found one of the following:
93 * - a subtree entry which does not match the key
94 * - a note entry which may or may not match the key
95 * - an unused leaf node (NULL)
96 * In any case, set *tree and *n, and return pointer to the tree location.
98 static void **note_tree_search(struct notes_tree *t, struct int_node **tree,
99 unsigned char *n, const unsigned char *key_sha1)
101 struct leaf_node *l;
102 unsigned char i;
103 void *p = (*tree)->a[0];
105 if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) {
106 l = (struct leaf_node *) CLR_PTR_TYPE(p);
107 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_oid.hash)) {
108 /* unpack tree and resume search */
109 (*tree)->a[0] = NULL;
110 load_subtree(t, l, *tree, *n);
111 free(l);
112 return note_tree_search(t, tree, n, key_sha1);
116 i = GET_NIBBLE(*n, key_sha1);
117 p = (*tree)->a[i];
118 switch (GET_PTR_TYPE(p)) {
119 case PTR_TYPE_INTERNAL:
120 *tree = CLR_PTR_TYPE(p);
121 (*n)++;
122 return note_tree_search(t, tree, n, key_sha1);
123 case PTR_TYPE_SUBTREE:
124 l = (struct leaf_node *) CLR_PTR_TYPE(p);
125 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_oid.hash)) {
126 /* unpack tree and resume search */
127 (*tree)->a[i] = NULL;
128 load_subtree(t, l, *tree, *n);
129 free(l);
130 return note_tree_search(t, tree, n, key_sha1);
132 /* fall through */
133 default:
134 return &((*tree)->a[i]);
139 * To find a leaf_node:
140 * Search to the tree location appropriate for the given key:
141 * If a note entry with matching key, return the note entry, else return NULL.
143 static struct leaf_node *note_tree_find(struct notes_tree *t,
144 struct int_node *tree, unsigned char n,
145 const unsigned char *key_sha1)
147 void **p = note_tree_search(t, &tree, &n, key_sha1);
148 if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) {
149 struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p);
150 if (!hashcmp(key_sha1, l->key_oid.hash))
151 return l;
153 return NULL;
157 * How to consolidate an int_node:
158 * If there are > 1 non-NULL entries, give up and return non-zero.
159 * Otherwise replace the int_node at the given index in the given parent node
160 * with the only NOTE entry (or a NULL entry if no entries) from the given
161 * tree, and return 0.
163 static int note_tree_consolidate(struct int_node *tree,
164 struct int_node *parent, unsigned char index)
166 unsigned int i;
167 void *p = NULL;
169 assert(tree && parent);
170 assert(CLR_PTR_TYPE(parent->a[index]) == tree);
172 for (i = 0; i < 16; i++) {
173 if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) {
174 if (p) /* more than one entry */
175 return -2;
176 p = tree->a[i];
180 if (p && (GET_PTR_TYPE(p) != PTR_TYPE_NOTE))
181 return -2;
182 /* replace tree with p in parent[index] */
183 parent->a[index] = p;
184 free(tree);
185 return 0;
189 * To remove a leaf_node:
190 * Search to the tree location appropriate for the given leaf_node's key:
191 * - If location does not hold a matching entry, abort and do nothing.
192 * - Copy the matching entry's value into the given entry.
193 * - Replace the matching leaf_node with a NULL entry (and free the leaf_node).
194 * - Consolidate int_nodes repeatedly, while walking up the tree towards root.
196 static void note_tree_remove(struct notes_tree *t,
197 struct int_node *tree, unsigned char n,
198 struct leaf_node *entry)
200 struct leaf_node *l;
201 struct int_node *parent_stack[GIT_SHA1_RAWSZ];
202 unsigned char i, j;
203 void **p = note_tree_search(t, &tree, &n, entry->key_oid.hash);
205 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
206 if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
207 return; /* type mismatch, nothing to remove */
208 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
209 if (oidcmp(&l->key_oid, &entry->key_oid))
210 return; /* key mismatch, nothing to remove */
212 /* we have found a matching entry */
213 oidcpy(&entry->val_oid, &l->val_oid);
214 free(l);
215 *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
217 /* consolidate this tree level, and parent levels, if possible */
218 if (!n)
219 return; /* cannot consolidate top level */
220 /* first, build stack of ancestors between root and current node */
221 parent_stack[0] = t->root;
222 for (i = 0; i < n; i++) {
223 j = GET_NIBBLE(i, entry->key_oid.hash);
224 parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]);
226 assert(i == n && parent_stack[i] == tree);
227 /* next, unwind stack until note_tree_consolidate() is done */
228 while (i > 0 &&
229 !note_tree_consolidate(parent_stack[i], parent_stack[i - 1],
230 GET_NIBBLE(i - 1, entry->key_oid.hash)))
231 i--;
235 * To insert a leaf_node:
236 * Search to the tree location appropriate for the given leaf_node's key:
237 * - If location is unused (NULL), store the tweaked pointer directly there
238 * - If location holds a note entry that matches the note-to-be-inserted, then
239 * combine the two notes (by calling the given combine_notes function).
240 * - If location holds a note entry that matches the subtree-to-be-inserted,
241 * then unpack the subtree-to-be-inserted into the location.
242 * - If location holds a matching subtree entry, unpack the subtree at that
243 * location, and restart the insert operation from that level.
244 * - Else, create a new int_node, holding both the node-at-location and the
245 * node-to-be-inserted, and store the new int_node into the location.
247 static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
248 unsigned char n, struct leaf_node *entry, unsigned char type,
249 combine_notes_fn combine_notes)
251 struct int_node *new_node;
252 struct leaf_node *l;
253 void **p = note_tree_search(t, &tree, &n, entry->key_oid.hash);
254 int ret = 0;
256 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
257 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
258 switch (GET_PTR_TYPE(*p)) {
259 case PTR_TYPE_NULL:
260 assert(!*p);
261 if (is_null_oid(&entry->val_oid))
262 free(entry);
263 else
264 *p = SET_PTR_TYPE(entry, type);
265 return 0;
266 case PTR_TYPE_NOTE:
267 switch (type) {
268 case PTR_TYPE_NOTE:
269 if (!oidcmp(&l->key_oid, &entry->key_oid)) {
270 /* skip concatenation if l == entry */
271 if (!oidcmp(&l->val_oid, &entry->val_oid))
272 return 0;
274 ret = combine_notes(&l->val_oid,
275 &entry->val_oid);
276 if (!ret && is_null_oid(&l->val_oid))
277 note_tree_remove(t, tree, n, entry);
278 free(entry);
279 return ret;
281 break;
282 case PTR_TYPE_SUBTREE:
283 if (!SUBTREE_SHA1_PREFIXCMP(l->key_oid.hash,
284 entry->key_oid.hash)) {
285 /* unpack 'entry' */
286 load_subtree(t, entry, tree, n);
287 free(entry);
288 return 0;
290 break;
292 break;
293 case PTR_TYPE_SUBTREE:
294 if (!SUBTREE_SHA1_PREFIXCMP(entry->key_oid.hash, l->key_oid.hash)) {
295 /* unpack 'l' and restart insert */
296 *p = NULL;
297 load_subtree(t, l, tree, n);
298 free(l);
299 return note_tree_insert(t, tree, n, entry, type,
300 combine_notes);
302 break;
305 /* non-matching leaf_node */
306 assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
307 GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
308 if (is_null_oid(&entry->val_oid)) { /* skip insertion of empty note */
309 free(entry);
310 return 0;
312 new_node = (struct int_node *) xcalloc(1, sizeof(struct int_node));
313 ret = note_tree_insert(t, new_node, n + 1, l, GET_PTR_TYPE(*p),
314 combine_notes);
315 if (ret)
316 return ret;
317 *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
318 return note_tree_insert(t, new_node, n + 1, entry, type, combine_notes);
321 /* Free the entire notes data contained in the given tree */
322 static void note_tree_free(struct int_node *tree)
324 unsigned int i;
325 for (i = 0; i < 16; i++) {
326 void *p = tree->a[i];
327 switch (GET_PTR_TYPE(p)) {
328 case PTR_TYPE_INTERNAL:
329 note_tree_free(CLR_PTR_TYPE(p));
330 /* fall through */
331 case PTR_TYPE_NOTE:
332 case PTR_TYPE_SUBTREE:
333 free(CLR_PTR_TYPE(p));
338 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
340 return strcmp(a->path, b->path);
343 /* note: takes ownership of path string */
344 static void add_non_note(struct notes_tree *t, char *path,
345 unsigned int mode, const unsigned char *sha1)
347 struct non_note *p = t->prev_non_note, *n;
348 n = (struct non_note *) xmalloc(sizeof(struct non_note));
349 n->next = NULL;
350 n->path = path;
351 n->mode = mode;
352 hashcpy(n->oid.hash, sha1);
353 t->prev_non_note = n;
355 if (!t->first_non_note) {
356 t->first_non_note = n;
357 return;
360 if (non_note_cmp(p, n) < 0)
361 ; /* do nothing */
362 else if (non_note_cmp(t->first_non_note, n) <= 0)
363 p = t->first_non_note;
364 else {
365 /* n sorts before t->first_non_note */
366 n->next = t->first_non_note;
367 t->first_non_note = n;
368 return;
371 /* n sorts equal or after p */
372 while (p->next && non_note_cmp(p->next, n) <= 0)
373 p = p->next;
375 if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
376 assert(strcmp(p->path, n->path) == 0);
377 p->mode = n->mode;
378 oidcpy(&p->oid, &n->oid);
379 free(n);
380 t->prev_non_note = p;
381 return;
384 /* n sorts between p and p->next */
385 n->next = p->next;
386 p->next = n;
389 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
390 struct int_node *node, unsigned int n)
392 struct object_id object_oid;
393 size_t prefix_len;
394 void *buf;
395 struct tree_desc desc;
396 struct name_entry entry;
398 buf = fill_tree_descriptor(&desc, &subtree->val_oid);
399 if (!buf)
400 die("Could not read %s for notes-index",
401 oid_to_hex(&subtree->val_oid));
403 prefix_len = subtree->key_oid.hash[KEY_INDEX];
404 if (prefix_len >= GIT_SHA1_RAWSZ)
405 BUG("prefix_len (%"PRIuMAX") is out of range", (uintmax_t)prefix_len);
406 if (prefix_len * 2 < n)
407 BUG("prefix_len (%"PRIuMAX") is too small", (uintmax_t)prefix_len);
408 memcpy(object_oid.hash, subtree->key_oid.hash, prefix_len);
409 while (tree_entry(&desc, &entry)) {
410 unsigned char type;
411 struct leaf_node *l;
412 size_t path_len = strlen(entry.path);
414 if (path_len == 2 * (GIT_SHA1_RAWSZ - prefix_len)) {
415 /* This is potentially the remainder of the SHA-1 */
417 if (!S_ISREG(entry.mode))
418 /* notes must be blobs */
419 goto handle_non_note;
421 if (hex_to_bytes(object_oid.hash + prefix_len, entry.path,
422 GIT_SHA1_RAWSZ - prefix_len))
423 goto handle_non_note; /* entry.path is not a SHA1 */
425 type = PTR_TYPE_NOTE;
426 } else if (path_len == 2) {
427 /* This is potentially an internal node */
428 size_t len = prefix_len;
430 if (!S_ISDIR(entry.mode))
431 /* internal nodes must be trees */
432 goto handle_non_note;
434 if (hex_to_bytes(object_oid.hash + len++, entry.path, 1))
435 goto handle_non_note; /* entry.path is not a SHA1 */
438 * Pad the rest of the SHA-1 with zeros,
439 * except for the last byte, where we write
440 * the length:
442 memset(object_oid.hash + len, 0, GIT_SHA1_RAWSZ - len - 1);
443 object_oid.hash[KEY_INDEX] = (unsigned char)len;
445 type = PTR_TYPE_SUBTREE;
446 } else {
447 /* This can't be part of a note */
448 goto handle_non_note;
451 l = xcalloc(1, sizeof(*l));
452 oidcpy(&l->key_oid, &object_oid);
453 oidcpy(&l->val_oid, entry.oid);
454 if (note_tree_insert(t, node, n, l, type,
455 combine_notes_concatenate))
456 die("Failed to load %s %s into notes tree "
457 "from %s",
458 type == PTR_TYPE_NOTE ? "note" : "subtree",
459 oid_to_hex(&l->key_oid), t->ref);
461 continue;
463 handle_non_note:
465 * Determine full path for this non-note entry. The
466 * filename is already found in entry.path, but the
467 * directory part of the path must be deduced from the
468 * subtree containing this entry based on our
469 * knowledge that the overall notes tree follows a
470 * strict byte-based progressive fanout structure
471 * (i.e. using 2/38, 2/2/36, etc. fanouts).
474 struct strbuf non_note_path = STRBUF_INIT;
475 const char *q = oid_to_hex(&subtree->key_oid);
476 size_t i;
477 for (i = 0; i < prefix_len; i++) {
478 strbuf_addch(&non_note_path, *q++);
479 strbuf_addch(&non_note_path, *q++);
480 strbuf_addch(&non_note_path, '/');
482 strbuf_addstr(&non_note_path, entry.path);
483 add_non_note(t, strbuf_detach(&non_note_path, NULL),
484 entry.mode, entry.oid->hash);
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 /* hex SHA1 + 19 * '/' + NUL */
531 #define FANOUT_PATH_MAX GIT_SHA1_HEXSZ + FANOUT_PATH_SEPARATORS + 1
533 static void construct_path_with_fanout(const unsigned char *sha1,
534 unsigned char fanout, char *path)
536 unsigned int i = 0, j = 0;
537 const char *hex_sha1 = sha1_to_hex(sha1);
538 assert(fanout < GIT_SHA1_RAWSZ);
539 while (fanout) {
540 path[i++] = hex_sha1[j++];
541 path[i++] = hex_sha1[j++];
542 path[i++] = '/';
543 fanout--;
545 xsnprintf(path + i, FANOUT_PATH_MAX - i, "%s", hex_sha1 + j);
548 static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
549 unsigned char n, unsigned char fanout, int flags,
550 each_note_fn fn, void *cb_data)
552 unsigned int i;
553 void *p;
554 int ret = 0;
555 struct leaf_node *l;
556 static char path[FANOUT_PATH_MAX];
558 fanout = determine_fanout(tree, n, fanout);
559 for (i = 0; i < 16; i++) {
560 redo:
561 p = tree->a[i];
562 switch (GET_PTR_TYPE(p)) {
563 case PTR_TYPE_INTERNAL:
564 /* recurse into int_node */
565 ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
566 fanout, flags, fn, cb_data);
567 break;
568 case PTR_TYPE_SUBTREE:
569 l = (struct leaf_node *) CLR_PTR_TYPE(p);
571 * Subtree entries in the note tree represent parts of
572 * the note tree that have not yet been explored. There
573 * is a direct relationship between subtree entries at
574 * level 'n' in the tree, and the 'fanout' variable:
575 * Subtree entries at level 'n <= 2 * fanout' should be
576 * preserved, since they correspond exactly to a fanout
577 * directory in the on-disk structure. However, subtree
578 * entries at level 'n > 2 * fanout' should NOT be
579 * preserved, but rather consolidated into the above
580 * notes tree level. We achieve this by unconditionally
581 * unpacking subtree entries that exist below the
582 * threshold level at 'n = 2 * fanout'.
584 if (n <= 2 * fanout &&
585 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
586 /* invoke callback with subtree */
587 unsigned int path_len =
588 l->key_oid.hash[KEY_INDEX] * 2 + fanout;
589 assert(path_len < FANOUT_PATH_MAX - 1);
590 construct_path_with_fanout(l->key_oid.hash,
591 fanout,
592 path);
593 /* Create trailing slash, if needed */
594 if (path[path_len - 1] != '/')
595 path[path_len++] = '/';
596 path[path_len] = '\0';
597 ret = fn(&l->key_oid, &l->val_oid,
598 path,
599 cb_data);
601 if (n > fanout * 2 ||
602 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
603 /* unpack subtree and resume traversal */
604 tree->a[i] = NULL;
605 load_subtree(t, l, tree, n);
606 free(l);
607 goto redo;
609 break;
610 case PTR_TYPE_NOTE:
611 l = (struct leaf_node *) CLR_PTR_TYPE(p);
612 construct_path_with_fanout(l->key_oid.hash, fanout,
613 path);
614 ret = fn(&l->key_oid, &l->val_oid, path,
615 cb_data);
616 break;
618 if (ret)
619 return ret;
621 return 0;
624 struct tree_write_stack {
625 struct tree_write_stack *next;
626 struct strbuf buf;
627 char path[2]; /* path to subtree in next, if any */
630 static inline int matches_tree_write_stack(struct tree_write_stack *tws,
631 const char *full_path)
633 return full_path[0] == tws->path[0] &&
634 full_path[1] == tws->path[1] &&
635 full_path[2] == '/';
638 static void write_tree_entry(struct strbuf *buf, unsigned int mode,
639 const char *path, unsigned int path_len, const
640 unsigned char *sha1)
642 strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
643 strbuf_add(buf, sha1, GIT_SHA1_RAWSZ);
646 static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
647 const char *path)
649 struct tree_write_stack *n;
650 assert(!tws->next);
651 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
652 n = (struct tree_write_stack *)
653 xmalloc(sizeof(struct tree_write_stack));
654 n->next = NULL;
655 strbuf_init(&n->buf, 256 * (32 + GIT_SHA1_HEXSZ)); /* assume 256 entries per tree */
656 n->path[0] = n->path[1] = '\0';
657 tws->next = n;
658 tws->path[0] = path[0];
659 tws->path[1] = path[1];
662 static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
664 int ret;
665 struct tree_write_stack *n = tws->next;
666 struct object_id s;
667 if (n) {
668 ret = tree_write_stack_finish_subtree(n);
669 if (ret)
670 return ret;
671 ret = write_object_file(n->buf.buf, n->buf.len, tree_type, &s);
672 if (ret)
673 return ret;
674 strbuf_release(&n->buf);
675 free(n);
676 tws->next = NULL;
677 write_tree_entry(&tws->buf, 040000, tws->path, 2, s.hash);
678 tws->path[0] = tws->path[1] = '\0';
680 return 0;
683 static int write_each_note_helper(struct tree_write_stack *tws,
684 const char *path, unsigned int mode,
685 const struct object_id *oid)
687 size_t path_len = strlen(path);
688 unsigned int n = 0;
689 int ret;
691 /* Determine common part of tree write stack */
692 while (tws && 3 * n < path_len &&
693 matches_tree_write_stack(tws, path + 3 * n)) {
694 n++;
695 tws = tws->next;
698 /* tws point to last matching tree_write_stack entry */
699 ret = tree_write_stack_finish_subtree(tws);
700 if (ret)
701 return ret;
703 /* Start subtrees needed to satisfy path */
704 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
705 tree_write_stack_init_subtree(tws, path + 3 * n);
706 n++;
707 tws = tws->next;
710 /* There should be no more directory components in the given path */
711 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
713 /* Finally add given entry to the current tree object */
714 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
715 oid->hash);
717 return 0;
720 struct write_each_note_data {
721 struct tree_write_stack *root;
722 struct non_note *next_non_note;
725 static int write_each_non_note_until(const char *note_path,
726 struct write_each_note_data *d)
728 struct non_note *n = d->next_non_note;
729 int cmp = 0, ret;
730 while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
731 if (note_path && cmp == 0)
732 ; /* do nothing, prefer note to non-note */
733 else {
734 ret = write_each_note_helper(d->root, n->path, n->mode,
735 &n->oid);
736 if (ret)
737 return ret;
739 n = n->next;
741 d->next_non_note = n;
742 return 0;
745 static int write_each_note(const struct object_id *object_oid,
746 const struct object_id *note_oid, char *note_path,
747 void *cb_data)
749 struct write_each_note_data *d =
750 (struct write_each_note_data *) cb_data;
751 size_t note_path_len = strlen(note_path);
752 unsigned int mode = 0100644;
754 if (note_path[note_path_len - 1] == '/') {
755 /* subtree entry */
756 note_path_len--;
757 note_path[note_path_len] = '\0';
758 mode = 040000;
760 assert(note_path_len <= GIT_SHA1_HEXSZ + FANOUT_PATH_SEPARATORS);
762 /* Weave non-note entries into note entries */
763 return write_each_non_note_until(note_path, d) ||
764 write_each_note_helper(d->root, note_path, mode, note_oid);
767 struct note_delete_list {
768 struct note_delete_list *next;
769 const unsigned char *sha1;
772 static int prune_notes_helper(const struct object_id *object_oid,
773 const struct object_id *note_oid, char *note_path,
774 void *cb_data)
776 struct note_delete_list **l = (struct note_delete_list **) cb_data;
777 struct note_delete_list *n;
779 if (has_object_file(object_oid))
780 return 0; /* nothing to do for this note */
782 /* failed to find object => prune this note */
783 n = (struct note_delete_list *) xmalloc(sizeof(*n));
784 n->next = *l;
785 n->sha1 = object_oid->hash;
786 *l = n;
787 return 0;
790 int combine_notes_concatenate(struct object_id *cur_oid,
791 const struct object_id *new_oid)
793 char *cur_msg = NULL, *new_msg = NULL, *buf;
794 unsigned long cur_len, new_len, buf_len;
795 enum object_type cur_type, new_type;
796 int ret;
798 /* read in both note blob objects */
799 if (!is_null_oid(new_oid))
800 new_msg = read_object_file(new_oid, &new_type, &new_len);
801 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
802 free(new_msg);
803 return 0;
805 if (!is_null_oid(cur_oid))
806 cur_msg = read_object_file(cur_oid, &cur_type, &cur_len);
807 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
808 free(cur_msg);
809 free(new_msg);
810 oidcpy(cur_oid, new_oid);
811 return 0;
814 /* we will separate the notes by two newlines anyway */
815 if (cur_msg[cur_len - 1] == '\n')
816 cur_len--;
818 /* concatenate cur_msg and new_msg into buf */
819 buf_len = cur_len + 2 + new_len;
820 buf = (char *) xmalloc(buf_len);
821 memcpy(buf, cur_msg, cur_len);
822 buf[cur_len] = '\n';
823 buf[cur_len + 1] = '\n';
824 memcpy(buf + cur_len + 2, new_msg, new_len);
825 free(cur_msg);
826 free(new_msg);
828 /* create a new blob object from buf */
829 ret = write_object_file(buf, buf_len, blob_type, cur_oid);
830 free(buf);
831 return ret;
834 int combine_notes_overwrite(struct object_id *cur_oid,
835 const struct object_id *new_oid)
837 oidcpy(cur_oid, new_oid);
838 return 0;
841 int combine_notes_ignore(struct object_id *cur_oid,
842 const struct object_id *new_oid)
844 return 0;
848 * Add the lines from the named object to list, with trailing
849 * newlines removed.
851 static int string_list_add_note_lines(struct string_list *list,
852 const struct object_id *oid)
854 char *data;
855 unsigned long len;
856 enum object_type t;
858 if (is_null_oid(oid))
859 return 0;
861 /* read_sha1_file NUL-terminates */
862 data = read_object_file(oid, &t, &len);
863 if (t != OBJ_BLOB || !data || !len) {
864 free(data);
865 return t != OBJ_BLOB || !data;
869 * If the last line of the file is EOL-terminated, this will
870 * add an empty string to the list. But it will be removed
871 * later, along with any empty strings that came from empty
872 * lines within the file.
874 string_list_split(list, data, '\n', -1);
875 free(data);
876 return 0;
879 static int string_list_join_lines_helper(struct string_list_item *item,
880 void *cb_data)
882 struct strbuf *buf = cb_data;
883 strbuf_addstr(buf, item->string);
884 strbuf_addch(buf, '\n');
885 return 0;
888 int combine_notes_cat_sort_uniq(struct object_id *cur_oid,
889 const struct object_id *new_oid)
891 struct string_list sort_uniq_list = STRING_LIST_INIT_DUP;
892 struct strbuf buf = STRBUF_INIT;
893 int ret = 1;
895 /* read both note blob objects into unique_lines */
896 if (string_list_add_note_lines(&sort_uniq_list, cur_oid))
897 goto out;
898 if (string_list_add_note_lines(&sort_uniq_list, new_oid))
899 goto out;
900 string_list_remove_empty_items(&sort_uniq_list, 0);
901 string_list_sort(&sort_uniq_list);
902 string_list_remove_duplicates(&sort_uniq_list, 0);
904 /* create a new blob object from sort_uniq_list */
905 if (for_each_string_list(&sort_uniq_list,
906 string_list_join_lines_helper, &buf))
907 goto out;
909 ret = write_object_file(buf.buf, buf.len, blob_type, cur_oid);
911 out:
912 strbuf_release(&buf);
913 string_list_clear(&sort_uniq_list, 0);
914 return ret;
917 static int string_list_add_one_ref(const char *refname, const struct object_id *oid,
918 int flag, void *cb)
920 struct string_list *refs = cb;
921 if (!unsorted_string_list_has_string(refs, refname))
922 string_list_append(refs, refname);
923 return 0;
927 * The list argument must have strdup_strings set on it.
929 void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
931 assert(list->strdup_strings);
932 if (has_glob_specials(glob)) {
933 for_each_glob_ref(string_list_add_one_ref, glob, list);
934 } else {
935 struct object_id oid;
936 if (get_oid(glob, &oid))
937 warning("notes ref %s is invalid", glob);
938 if (!unsorted_string_list_has_string(list, glob))
939 string_list_append(list, glob);
943 void string_list_add_refs_from_colon_sep(struct string_list *list,
944 const char *globs)
946 struct string_list split = STRING_LIST_INIT_NODUP;
947 char *globs_copy = xstrdup(globs);
948 int i;
950 string_list_split_in_place(&split, globs_copy, ':', -1);
951 string_list_remove_empty_items(&split, 0);
953 for (i = 0; i < split.nr; i++)
954 string_list_add_refs_by_glob(list, split.items[i].string);
956 string_list_clear(&split, 0);
957 free(globs_copy);
960 static int notes_display_config(const char *k, const char *v, void *cb)
962 int *load_refs = cb;
964 if (*load_refs && !strcmp(k, "notes.displayref")) {
965 if (!v)
966 config_error_nonbool(k);
967 string_list_add_refs_by_glob(&display_notes_refs, v);
970 return 0;
973 const char *default_notes_ref(void)
975 const char *notes_ref = NULL;
976 if (!notes_ref)
977 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
978 if (!notes_ref)
979 notes_ref = notes_ref_name; /* value of core.notesRef config */
980 if (!notes_ref)
981 notes_ref = GIT_NOTES_DEFAULT_REF;
982 return notes_ref;
985 void init_notes(struct notes_tree *t, const char *notes_ref,
986 combine_notes_fn combine_notes, int flags)
988 struct object_id oid, object_oid;
989 unsigned mode;
990 struct leaf_node root_tree;
992 if (!t)
993 t = &default_notes_tree;
994 assert(!t->initialized);
996 if (!notes_ref)
997 notes_ref = default_notes_ref();
999 if (!combine_notes)
1000 combine_notes = combine_notes_concatenate;
1002 t->root = (struct int_node *) xcalloc(1, sizeof(struct int_node));
1003 t->first_non_note = NULL;
1004 t->prev_non_note = NULL;
1005 t->ref = xstrdup_or_null(notes_ref);
1006 t->update_ref = (flags & NOTES_INIT_WRITABLE) ? t->ref : NULL;
1007 t->combine_notes = combine_notes;
1008 t->initialized = 1;
1009 t->dirty = 0;
1011 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
1012 get_oid_treeish(notes_ref, &object_oid))
1013 return;
1014 if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, &object_oid))
1015 die("Cannot use notes ref %s", notes_ref);
1016 if (get_tree_entry(&object_oid, "", &oid, &mode))
1017 die("Failed to read notes tree referenced by %s (%s)",
1018 notes_ref, oid_to_hex(&object_oid));
1020 oidclr(&root_tree.key_oid);
1021 oidcpy(&root_tree.val_oid, &oid);
1022 load_subtree(t, &root_tree, t->root, 0);
1025 struct notes_tree **load_notes_trees(struct string_list *refs, int flags)
1027 struct string_list_item *item;
1028 int counter = 0;
1029 struct notes_tree **trees;
1030 ALLOC_ARRAY(trees, refs->nr + 1);
1031 for_each_string_list_item(item, refs) {
1032 struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
1033 init_notes(t, item->string, combine_notes_ignore, flags);
1034 trees[counter++] = t;
1036 trees[counter] = NULL;
1037 return trees;
1040 void init_display_notes(struct display_notes_opt *opt)
1042 char *display_ref_env;
1043 int load_config_refs = 0;
1044 display_notes_refs.strdup_strings = 1;
1046 assert(!display_notes_trees);
1048 if (!opt || opt->use_default_notes > 0 ||
1049 (opt->use_default_notes == -1 && !opt->extra_notes_refs.nr)) {
1050 string_list_append(&display_notes_refs, default_notes_ref());
1051 display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
1052 if (display_ref_env) {
1053 string_list_add_refs_from_colon_sep(&display_notes_refs,
1054 display_ref_env);
1055 load_config_refs = 0;
1056 } else
1057 load_config_refs = 1;
1060 git_config(notes_display_config, &load_config_refs);
1062 if (opt) {
1063 struct string_list_item *item;
1064 for_each_string_list_item(item, &opt->extra_notes_refs)
1065 string_list_add_refs_by_glob(&display_notes_refs,
1066 item->string);
1069 display_notes_trees = load_notes_trees(&display_notes_refs, 0);
1070 string_list_clear(&display_notes_refs, 0);
1073 int add_note(struct notes_tree *t, const struct object_id *object_oid,
1074 const struct object_id *note_oid, combine_notes_fn combine_notes)
1076 struct leaf_node *l;
1078 if (!t)
1079 t = &default_notes_tree;
1080 assert(t->initialized);
1081 t->dirty = 1;
1082 if (!combine_notes)
1083 combine_notes = t->combine_notes;
1084 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
1085 oidcpy(&l->key_oid, object_oid);
1086 oidcpy(&l->val_oid, note_oid);
1087 return note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
1090 int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1092 struct leaf_node l;
1094 if (!t)
1095 t = &default_notes_tree;
1096 assert(t->initialized);
1097 hashcpy(l.key_oid.hash, object_sha1);
1098 oidclr(&l.val_oid);
1099 note_tree_remove(t, t->root, 0, &l);
1100 if (is_null_oid(&l.val_oid)) /* no note was removed */
1101 return 1;
1102 t->dirty = 1;
1103 return 0;
1106 const struct object_id *get_note(struct notes_tree *t,
1107 const struct object_id *oid)
1109 struct leaf_node *found;
1111 if (!t)
1112 t = &default_notes_tree;
1113 assert(t->initialized);
1114 found = note_tree_find(t, t->root, 0, oid->hash);
1115 return found ? &found->val_oid : NULL;
1118 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
1119 void *cb_data)
1121 if (!t)
1122 t = &default_notes_tree;
1123 assert(t->initialized);
1124 return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
1127 int write_notes_tree(struct notes_tree *t, struct object_id *result)
1129 struct tree_write_stack root;
1130 struct write_each_note_data cb_data;
1131 int ret;
1132 int flags;
1134 if (!t)
1135 t = &default_notes_tree;
1136 assert(t->initialized);
1138 /* Prepare for traversal of current notes tree */
1139 root.next = NULL; /* last forward entry in list is grounded */
1140 strbuf_init(&root.buf, 256 * (32 + GIT_SHA1_HEXSZ)); /* assume 256 entries */
1141 root.path[0] = root.path[1] = '\0';
1142 cb_data.root = &root;
1143 cb_data.next_non_note = t->first_non_note;
1145 /* Write tree objects representing current notes tree */
1146 flags = FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
1147 FOR_EACH_NOTE_YIELD_SUBTREES;
1148 ret = for_each_note(t, flags, write_each_note, &cb_data) ||
1149 write_each_non_note_until(NULL, &cb_data) ||
1150 tree_write_stack_finish_subtree(&root) ||
1151 write_object_file(root.buf.buf, root.buf.len, tree_type, result);
1152 strbuf_release(&root.buf);
1153 return ret;
1156 void prune_notes(struct notes_tree *t, int flags)
1158 struct note_delete_list *l = NULL;
1160 if (!t)
1161 t = &default_notes_tree;
1162 assert(t->initialized);
1164 for_each_note(t, 0, prune_notes_helper, &l);
1166 while (l) {
1167 if (flags & NOTES_PRUNE_VERBOSE)
1168 printf("%s\n", sha1_to_hex(l->sha1));
1169 if (!(flags & NOTES_PRUNE_DRYRUN))
1170 remove_note(t, l->sha1);
1171 l = l->next;
1175 void free_notes(struct notes_tree *t)
1177 if (!t)
1178 t = &default_notes_tree;
1179 if (t->root)
1180 note_tree_free(t->root);
1181 free(t->root);
1182 while (t->first_non_note) {
1183 t->prev_non_note = t->first_non_note->next;
1184 free(t->first_non_note->path);
1185 free(t->first_non_note);
1186 t->first_non_note = t->prev_non_note;
1188 free(t->ref);
1189 memset(t, 0, sizeof(struct notes_tree));
1193 * Fill the given strbuf with the notes associated with the given object.
1195 * If the given notes_tree structure is not initialized, it will be auto-
1196 * initialized to the default value (see documentation for init_notes() above).
1197 * If the given notes_tree is NULL, the internal/default notes_tree will be
1198 * used instead.
1200 * (raw != 0) gives the %N userformat; otherwise, the note message is given
1201 * for human consumption.
1203 static void format_note(struct notes_tree *t, const struct object_id *object_oid,
1204 struct strbuf *sb, const char *output_encoding, int raw)
1206 static const char utf8[] = "utf-8";
1207 const struct object_id *oid;
1208 char *msg, *msg_p;
1209 unsigned long linelen, msglen;
1210 enum object_type type;
1212 if (!t)
1213 t = &default_notes_tree;
1214 if (!t->initialized)
1215 init_notes(t, NULL, NULL, 0);
1217 oid = get_note(t, object_oid);
1218 if (!oid)
1219 return;
1221 if (!(msg = read_object_file(oid, &type, &msglen)) || type != OBJ_BLOB) {
1222 free(msg);
1223 return;
1226 if (output_encoding && *output_encoding &&
1227 !is_encoding_utf8(output_encoding)) {
1228 char *reencoded = reencode_string(msg, output_encoding, utf8);
1229 if (reencoded) {
1230 free(msg);
1231 msg = reencoded;
1232 msglen = strlen(msg);
1236 /* we will end the annotation by a newline anyway */
1237 if (msglen && msg[msglen - 1] == '\n')
1238 msglen--;
1240 if (!raw) {
1241 const char *ref = t->ref;
1242 if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
1243 strbuf_addstr(sb, "\nNotes:\n");
1244 } else {
1245 if (starts_with(ref, "refs/"))
1246 ref += 5;
1247 if (starts_with(ref, "notes/"))
1248 ref += 6;
1249 strbuf_addf(sb, "\nNotes (%s):\n", ref);
1253 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
1254 linelen = strchrnul(msg_p, '\n') - msg_p;
1256 if (!raw)
1257 strbuf_addstr(sb, " ");
1258 strbuf_add(sb, msg_p, linelen);
1259 strbuf_addch(sb, '\n');
1262 free(msg);
1265 void format_display_notes(const struct object_id *object_oid,
1266 struct strbuf *sb, const char *output_encoding, int raw)
1268 int i;
1269 assert(display_notes_trees);
1270 for (i = 0; display_notes_trees[i]; i++)
1271 format_note(display_notes_trees[i], object_oid, sb,
1272 output_encoding, raw);
1275 int copy_note(struct notes_tree *t,
1276 const struct object_id *from_obj, const struct object_id *to_obj,
1277 int force, combine_notes_fn combine_notes)
1279 const struct object_id *note = get_note(t, from_obj);
1280 const struct object_id *existing_note = get_note(t, to_obj);
1282 if (!force && existing_note)
1283 return 1;
1285 if (note)
1286 return add_note(t, to_obj, note, combine_notes);
1287 else if (existing_note)
1288 return add_note(t, to_obj, &null_oid, combine_notes);
1290 return 0;
1293 void expand_notes_ref(struct strbuf *sb)
1295 if (starts_with(sb->buf, "refs/notes/"))
1296 return; /* we're happy */
1297 else if (starts_with(sb->buf, "notes/"))
1298 strbuf_insert(sb, 0, "refs/", 5);
1299 else
1300 strbuf_insert(sb, 0, "refs/notes/", 11);
1303 void expand_loose_notes_ref(struct strbuf *sb)
1305 struct object_id object;
1307 if (get_oid(sb->buf, &object)) {
1308 /* fallback to expand_notes_ref */
1309 expand_notes_ref(sb);