set_git_dir: handle feeding gitdir to itself
[git.git] / notes.c
blobf090c88363883e65cea66fd63b2c8dfb3f642b7d
1 #include "cache.h"
2 #include "config.h"
3 #include "notes.h"
4 #include "blob.h"
5 #include "tree.h"
6 #include "utf8.h"
7 #include "strbuf.h"
8 #include "tree-walk.h"
9 #include "string-list.h"
10 #include "refs.h"
13 * Use a non-balancing simple 16-tree structure with struct int_node as
14 * internal nodes, and struct leaf_node as leaf nodes. Each int_node has a
15 * 16-array of pointers to its children.
16 * The bottom 2 bits of each pointer is used to identify the pointer type
17 * - ptr & 3 == 0 - NULL pointer, assert(ptr == NULL)
18 * - ptr & 3 == 1 - pointer to next internal node - cast to struct int_node *
19 * - ptr & 3 == 2 - pointer to note entry - cast to struct leaf_node *
20 * - ptr & 3 == 3 - pointer to subtree entry - cast to struct leaf_node *
22 * The root node is a statically allocated struct int_node.
24 struct int_node {
25 void *a[16];
29 * Leaf nodes come in two variants, note entries and subtree entries,
30 * distinguished by the LSb of the leaf node pointer (see above).
31 * As a note entry, the key is the SHA1 of the referenced object, and the
32 * value is the SHA1 of the note object.
33 * As a subtree entry, the key is the prefix SHA1 (w/trailing NULs) of the
34 * referenced object, using the last byte of the key to store the length of
35 * the prefix. The value is the SHA1 of the tree object containing the notes
36 * subtree.
38 struct leaf_node {
39 struct object_id key_oid;
40 struct object_id val_oid;
44 * A notes tree may contain entries that are not notes, and that do not follow
45 * the naming conventions of notes. There are typically none/few of these, but
46 * we still need to keep track of them. Keep a simple linked list sorted alpha-
47 * betically on the non-note path. The list is populated when parsing tree
48 * objects in load_subtree(), and the non-notes are correctly written back into
49 * the tree objects produced by write_notes_tree().
51 struct non_note {
52 struct non_note *next; /* grounded (last->next == NULL) */
53 char *path;
54 unsigned int mode;
55 struct object_id oid;
58 #define PTR_TYPE_NULL 0
59 #define PTR_TYPE_INTERNAL 1
60 #define PTR_TYPE_NOTE 2
61 #define PTR_TYPE_SUBTREE 3
63 #define GET_PTR_TYPE(ptr) ((uintptr_t) (ptr) & 3)
64 #define CLR_PTR_TYPE(ptr) ((void *) ((uintptr_t) (ptr) & ~3))
65 #define SET_PTR_TYPE(ptr, type) ((void *) ((uintptr_t) (ptr) | (type)))
67 #define GET_NIBBLE(n, sha1) (((sha1[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f)
69 #define KEY_INDEX (GIT_SHA1_RAWSZ - 1)
70 #define FANOUT_PATH_SEPARATORS ((GIT_SHA1_HEXSZ / 2) - 1)
71 #define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
72 (memcmp(key_sha1, subtree_sha1, subtree_sha1[KEY_INDEX]))
74 struct notes_tree default_notes_tree;
76 static struct string_list display_notes_refs = STRING_LIST_INIT_NODUP;
77 static struct notes_tree **display_notes_trees;
79 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
80 struct int_node *node, unsigned int n);
83 * Search the tree until the appropriate location for the given key is found:
84 * 1. Start at the root node, with n = 0
85 * 2. If a[0] at the current level is a matching subtree entry, unpack that
86 * subtree entry and remove it; restart search at the current level.
87 * 3. Use the nth nibble of the key as an index into a:
88 * - If a[n] is an int_node, recurse from #2 into that node and increment n
89 * - If a matching subtree entry, unpack that subtree entry (and remove it);
90 * restart search at the current level.
91 * - Otherwise, we have found one of the following:
92 * - a subtree entry which does not match the key
93 * - a note entry which may or may not match the key
94 * - an unused leaf node (NULL)
95 * In any case, set *tree and *n, and return pointer to the tree location.
97 static void **note_tree_search(struct notes_tree *t, struct int_node **tree,
98 unsigned char *n, const unsigned char *key_sha1)
100 struct leaf_node *l;
101 unsigned char i;
102 void *p = (*tree)->a[0];
104 if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) {
105 l = (struct leaf_node *) CLR_PTR_TYPE(p);
106 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_oid.hash)) {
107 /* unpack tree and resume search */
108 (*tree)->a[0] = NULL;
109 load_subtree(t, l, *tree, *n);
110 free(l);
111 return note_tree_search(t, tree, n, key_sha1);
115 i = GET_NIBBLE(*n, key_sha1);
116 p = (*tree)->a[i];
117 switch (GET_PTR_TYPE(p)) {
118 case PTR_TYPE_INTERNAL:
119 *tree = CLR_PTR_TYPE(p);
120 (*n)++;
121 return note_tree_search(t, tree, n, key_sha1);
122 case PTR_TYPE_SUBTREE:
123 l = (struct leaf_node *) CLR_PTR_TYPE(p);
124 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_oid.hash)) {
125 /* unpack tree and resume search */
126 (*tree)->a[i] = NULL;
127 load_subtree(t, l, *tree, *n);
128 free(l);
129 return note_tree_search(t, tree, n, key_sha1);
131 /* fall through */
132 default:
133 return &((*tree)->a[i]);
138 * To find a leaf_node:
139 * Search to the tree location appropriate for the given key:
140 * If a note entry with matching key, return the note entry, else return NULL.
142 static struct leaf_node *note_tree_find(struct notes_tree *t,
143 struct int_node *tree, unsigned char n,
144 const unsigned char *key_sha1)
146 void **p = note_tree_search(t, &tree, &n, key_sha1);
147 if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) {
148 struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p);
149 if (!hashcmp(key_sha1, l->key_oid.hash))
150 return l;
152 return NULL;
156 * How to consolidate an int_node:
157 * If there are > 1 non-NULL entries, give up and return non-zero.
158 * Otherwise replace the int_node at the given index in the given parent node
159 * with the only NOTE entry (or a NULL entry if no entries) from the given
160 * tree, and return 0.
162 static int note_tree_consolidate(struct int_node *tree,
163 struct int_node *parent, unsigned char index)
165 unsigned int i;
166 void *p = NULL;
168 assert(tree && parent);
169 assert(CLR_PTR_TYPE(parent->a[index]) == tree);
171 for (i = 0; i < 16; i++) {
172 if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) {
173 if (p) /* more than one entry */
174 return -2;
175 p = tree->a[i];
179 if (p && (GET_PTR_TYPE(p) != PTR_TYPE_NOTE))
180 return -2;
181 /* replace tree with p in parent[index] */
182 parent->a[index] = p;
183 free(tree);
184 return 0;
188 * To remove a leaf_node:
189 * Search to the tree location appropriate for the given leaf_node's key:
190 * - If location does not hold a matching entry, abort and do nothing.
191 * - Copy the matching entry's value into the given entry.
192 * - Replace the matching leaf_node with a NULL entry (and free the leaf_node).
193 * - Consolidate int_nodes repeatedly, while walking up the tree towards root.
195 static void note_tree_remove(struct notes_tree *t,
196 struct int_node *tree, unsigned char n,
197 struct leaf_node *entry)
199 struct leaf_node *l;
200 struct int_node *parent_stack[GIT_SHA1_RAWSZ];
201 unsigned char i, j;
202 void **p = note_tree_search(t, &tree, &n, entry->key_oid.hash);
204 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
205 if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
206 return; /* type mismatch, nothing to remove */
207 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
208 if (oidcmp(&l->key_oid, &entry->key_oid))
209 return; /* key mismatch, nothing to remove */
211 /* we have found a matching entry */
212 oidcpy(&entry->val_oid, &l->val_oid);
213 free(l);
214 *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
216 /* consolidate this tree level, and parent levels, if possible */
217 if (!n)
218 return; /* cannot consolidate top level */
219 /* first, build stack of ancestors between root and current node */
220 parent_stack[0] = t->root;
221 for (i = 0; i < n; i++) {
222 j = GET_NIBBLE(i, entry->key_oid.hash);
223 parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]);
225 assert(i == n && parent_stack[i] == tree);
226 /* next, unwind stack until note_tree_consolidate() is done */
227 while (i > 0 &&
228 !note_tree_consolidate(parent_stack[i], parent_stack[i - 1],
229 GET_NIBBLE(i - 1, entry->key_oid.hash)))
230 i--;
234 * To insert a leaf_node:
235 * Search to the tree location appropriate for the given leaf_node's key:
236 * - If location is unused (NULL), store the tweaked pointer directly there
237 * - If location holds a note entry that matches the note-to-be-inserted, then
238 * combine the two notes (by calling the given combine_notes function).
239 * - If location holds a note entry that matches the subtree-to-be-inserted,
240 * then unpack the subtree-to-be-inserted into the location.
241 * - If location holds a matching subtree entry, unpack the subtree at that
242 * location, and restart the insert operation from that level.
243 * - Else, create a new int_node, holding both the node-at-location and the
244 * node-to-be-inserted, and store the new int_node into the location.
246 static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
247 unsigned char n, struct leaf_node *entry, unsigned char type,
248 combine_notes_fn combine_notes)
250 struct int_node *new_node;
251 struct leaf_node *l;
252 void **p = note_tree_search(t, &tree, &n, entry->key_oid.hash);
253 int ret = 0;
255 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
256 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
257 switch (GET_PTR_TYPE(*p)) {
258 case PTR_TYPE_NULL:
259 assert(!*p);
260 if (is_null_oid(&entry->val_oid))
261 free(entry);
262 else
263 *p = SET_PTR_TYPE(entry, type);
264 return 0;
265 case PTR_TYPE_NOTE:
266 switch (type) {
267 case PTR_TYPE_NOTE:
268 if (!oidcmp(&l->key_oid, &entry->key_oid)) {
269 /* skip concatenation if l == entry */
270 if (!oidcmp(&l->val_oid, &entry->val_oid))
271 return 0;
273 ret = combine_notes(l->val_oid.hash,
274 entry->val_oid.hash);
275 if (!ret && is_null_oid(&l->val_oid))
276 note_tree_remove(t, tree, n, entry);
277 free(entry);
278 return ret;
280 break;
281 case PTR_TYPE_SUBTREE:
282 if (!SUBTREE_SHA1_PREFIXCMP(l->key_oid.hash,
283 entry->key_oid.hash)) {
284 /* unpack 'entry' */
285 load_subtree(t, entry, tree, n);
286 free(entry);
287 return 0;
289 break;
291 break;
292 case PTR_TYPE_SUBTREE:
293 if (!SUBTREE_SHA1_PREFIXCMP(entry->key_oid.hash, l->key_oid.hash)) {
294 /* unpack 'l' and restart insert */
295 *p = NULL;
296 load_subtree(t, l, tree, n);
297 free(l);
298 return note_tree_insert(t, tree, n, entry, type,
299 combine_notes);
301 break;
304 /* non-matching leaf_node */
305 assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
306 GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
307 if (is_null_oid(&entry->val_oid)) { /* skip insertion of empty note */
308 free(entry);
309 return 0;
311 new_node = (struct int_node *) xcalloc(1, sizeof(struct int_node));
312 ret = note_tree_insert(t, new_node, n + 1, l, GET_PTR_TYPE(*p),
313 combine_notes);
314 if (ret)
315 return ret;
316 *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
317 return note_tree_insert(t, new_node, n + 1, entry, type, combine_notes);
320 /* Free the entire notes data contained in the given tree */
321 static void note_tree_free(struct int_node *tree)
323 unsigned int i;
324 for (i = 0; i < 16; i++) {
325 void *p = tree->a[i];
326 switch (GET_PTR_TYPE(p)) {
327 case PTR_TYPE_INTERNAL:
328 note_tree_free(CLR_PTR_TYPE(p));
329 /* fall through */
330 case PTR_TYPE_NOTE:
331 case PTR_TYPE_SUBTREE:
332 free(CLR_PTR_TYPE(p));
338 * Convert a partial SHA1 hex string to the corresponding partial SHA1 value.
339 * - hex - Partial SHA1 segment in ASCII hex format
340 * - hex_len - Length of above segment. Must be multiple of 2 between 0 and 40
341 * - sha1 - Partial SHA1 value is written here
342 * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20
343 * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format)).
344 * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2).
345 * Pads sha1 with NULs up to sha1_len (not included in returned length).
347 static int get_oid_hex_segment(const char *hex, unsigned int hex_len,
348 unsigned char *oid, unsigned int oid_len)
350 unsigned int i, len = hex_len >> 1;
351 if (hex_len % 2 != 0 || len > oid_len)
352 return -1;
353 for (i = 0; i < len; i++) {
354 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
355 if (val & ~0xff)
356 return -1;
357 *oid++ = val;
358 hex += 2;
360 for (; i < oid_len; i++)
361 *oid++ = 0;
362 return len;
365 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
367 return strcmp(a->path, b->path);
370 /* note: takes ownership of path string */
371 static void add_non_note(struct notes_tree *t, char *path,
372 unsigned int mode, const unsigned char *sha1)
374 struct non_note *p = t->prev_non_note, *n;
375 n = (struct non_note *) xmalloc(sizeof(struct non_note));
376 n->next = NULL;
377 n->path = path;
378 n->mode = mode;
379 hashcpy(n->oid.hash, sha1);
380 t->prev_non_note = n;
382 if (!t->first_non_note) {
383 t->first_non_note = n;
384 return;
387 if (non_note_cmp(p, n) < 0)
388 ; /* do nothing */
389 else if (non_note_cmp(t->first_non_note, n) <= 0)
390 p = t->first_non_note;
391 else {
392 /* n sorts before t->first_non_note */
393 n->next = t->first_non_note;
394 t->first_non_note = n;
395 return;
398 /* n sorts equal or after p */
399 while (p->next && non_note_cmp(p->next, n) <= 0)
400 p = p->next;
402 if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
403 assert(strcmp(p->path, n->path) == 0);
404 p->mode = n->mode;
405 oidcpy(&p->oid, &n->oid);
406 free(n);
407 t->prev_non_note = p;
408 return;
411 /* n sorts between p and p->next */
412 n->next = p->next;
413 p->next = n;
416 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
417 struct int_node *node, unsigned int n)
419 struct object_id object_oid;
420 unsigned int prefix_len;
421 void *buf;
422 struct tree_desc desc;
423 struct name_entry entry;
424 int len, path_len;
425 unsigned char type;
426 struct leaf_node *l;
428 buf = fill_tree_descriptor(&desc, &subtree->val_oid);
429 if (!buf)
430 die("Could not read %s for notes-index",
431 oid_to_hex(&subtree->val_oid));
433 prefix_len = subtree->key_oid.hash[KEY_INDEX];
434 assert(prefix_len * 2 >= n);
435 memcpy(object_oid.hash, subtree->key_oid.hash, prefix_len);
436 while (tree_entry(&desc, &entry)) {
437 path_len = strlen(entry.path);
438 len = get_oid_hex_segment(entry.path, path_len,
439 object_oid.hash + prefix_len, GIT_SHA1_RAWSZ - prefix_len);
440 if (len < 0)
441 goto handle_non_note; /* entry.path is not a SHA1 */
442 len += prefix_len;
445 * If object SHA1 is complete (len == 20), assume note object
446 * If object SHA1 is incomplete (len < 20), and current
447 * component consists of 2 hex chars, assume note subtree
449 if (len <= GIT_SHA1_RAWSZ) {
450 type = PTR_TYPE_NOTE;
451 l = (struct leaf_node *)
452 xcalloc(1, sizeof(struct leaf_node));
453 oidcpy(&l->key_oid, &object_oid);
454 oidcpy(&l->val_oid, entry.oid);
455 if (len < GIT_SHA1_RAWSZ) {
456 if (!S_ISDIR(entry.mode) || path_len != 2)
457 goto handle_non_note; /* not subtree */
458 l->key_oid.hash[KEY_INDEX] = (unsigned char) len;
459 type = PTR_TYPE_SUBTREE;
461 if (note_tree_insert(t, node, n, l, type,
462 combine_notes_concatenate))
463 die("Failed to load %s %s into notes tree "
464 "from %s",
465 type == PTR_TYPE_NOTE ? "note" : "subtree",
466 oid_to_hex(&l->key_oid), t->ref);
468 continue;
470 handle_non_note:
472 * Determine full path for this non-note entry:
473 * The filename is already found in entry.path, but the
474 * directory part of the path must be deduced from the subtree
475 * containing this entry. We assume here that the overall notes
476 * tree follows a strict byte-based progressive fanout
477 * structure (i.e. using 2/38, 2/2/36, etc. fanouts, and not
478 * e.g. 4/36 fanout). This means that if a non-note is found at
479 * path "dead/beef", the following code will register it as
480 * being found on "de/ad/beef".
481 * On the other hand, if you use such non-obvious non-note
482 * paths in the middle of a notes tree, you deserve what's
483 * coming to you ;). Note that for non-notes that are not
484 * SHA1-like at the top level, there will be no problems.
486 * To conclude, it is strongly advised to make sure non-notes
487 * have at least one non-hex character in the top-level path
488 * component.
491 struct strbuf non_note_path = STRBUF_INIT;
492 const char *q = oid_to_hex(&subtree->key_oid);
493 int i;
494 for (i = 0; i < prefix_len; i++) {
495 strbuf_addch(&non_note_path, *q++);
496 strbuf_addch(&non_note_path, *q++);
497 strbuf_addch(&non_note_path, '/');
499 strbuf_addstr(&non_note_path, entry.path);
500 add_non_note(t, strbuf_detach(&non_note_path, NULL),
501 entry.mode, entry.oid->hash);
504 free(buf);
508 * Determine optimal on-disk fanout for this part of the notes tree
510 * Given a (sub)tree and the level in the internal tree structure, determine
511 * whether or not the given existing fanout should be expanded for this
512 * (sub)tree.
514 * Values of the 'fanout' variable:
515 * - 0: No fanout (all notes are stored directly in the root notes tree)
516 * - 1: 2/38 fanout
517 * - 2: 2/2/36 fanout
518 * - 3: 2/2/2/34 fanout
519 * etc.
521 static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
522 unsigned char fanout)
525 * The following is a simple heuristic that works well in practice:
526 * For each even-numbered 16-tree level (remember that each on-disk
527 * fanout level corresponds to _two_ 16-tree levels), peek at all 16
528 * entries at that tree level. If all of them are either int_nodes or
529 * subtree entries, then there are likely plenty of notes below this
530 * level, so we return an incremented fanout.
532 unsigned int i;
533 if ((n % 2) || (n > 2 * fanout))
534 return fanout;
535 for (i = 0; i < 16; i++) {
536 switch (GET_PTR_TYPE(tree->a[i])) {
537 case PTR_TYPE_SUBTREE:
538 case PTR_TYPE_INTERNAL:
539 continue;
540 default:
541 return fanout;
544 return fanout + 1;
547 /* hex SHA1 + 19 * '/' + NUL */
548 #define FANOUT_PATH_MAX GIT_SHA1_HEXSZ + FANOUT_PATH_SEPARATORS + 1
550 static void construct_path_with_fanout(const unsigned char *sha1,
551 unsigned char fanout, char *path)
553 unsigned int i = 0, j = 0;
554 const char *hex_sha1 = sha1_to_hex(sha1);
555 assert(fanout < GIT_SHA1_RAWSZ);
556 while (fanout) {
557 path[i++] = hex_sha1[j++];
558 path[i++] = hex_sha1[j++];
559 path[i++] = '/';
560 fanout--;
562 xsnprintf(path + i, FANOUT_PATH_MAX - i, "%s", hex_sha1 + j);
565 static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
566 unsigned char n, unsigned char fanout, int flags,
567 each_note_fn fn, void *cb_data)
569 unsigned int i;
570 void *p;
571 int ret = 0;
572 struct leaf_node *l;
573 static char path[FANOUT_PATH_MAX];
575 fanout = determine_fanout(tree, n, fanout);
576 for (i = 0; i < 16; i++) {
577 redo:
578 p = tree->a[i];
579 switch (GET_PTR_TYPE(p)) {
580 case PTR_TYPE_INTERNAL:
581 /* recurse into int_node */
582 ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
583 fanout, flags, fn, cb_data);
584 break;
585 case PTR_TYPE_SUBTREE:
586 l = (struct leaf_node *) CLR_PTR_TYPE(p);
588 * Subtree entries in the note tree represent parts of
589 * the note tree that have not yet been explored. There
590 * is a direct relationship between subtree entries at
591 * level 'n' in the tree, and the 'fanout' variable:
592 * Subtree entries at level 'n <= 2 * fanout' should be
593 * preserved, since they correspond exactly to a fanout
594 * directory in the on-disk structure. However, subtree
595 * entries at level 'n > 2 * fanout' should NOT be
596 * preserved, but rather consolidated into the above
597 * notes tree level. We achieve this by unconditionally
598 * unpacking subtree entries that exist below the
599 * threshold level at 'n = 2 * fanout'.
601 if (n <= 2 * fanout &&
602 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
603 /* invoke callback with subtree */
604 unsigned int path_len =
605 l->key_oid.hash[KEY_INDEX] * 2 + fanout;
606 assert(path_len < FANOUT_PATH_MAX - 1);
607 construct_path_with_fanout(l->key_oid.hash,
608 fanout,
609 path);
610 /* Create trailing slash, if needed */
611 if (path[path_len - 1] != '/')
612 path[path_len++] = '/';
613 path[path_len] = '\0';
614 ret = fn(&l->key_oid, &l->val_oid,
615 path,
616 cb_data);
618 if (n > fanout * 2 ||
619 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
620 /* unpack subtree and resume traversal */
621 tree->a[i] = NULL;
622 load_subtree(t, l, tree, n);
623 free(l);
624 goto redo;
626 break;
627 case PTR_TYPE_NOTE:
628 l = (struct leaf_node *) CLR_PTR_TYPE(p);
629 construct_path_with_fanout(l->key_oid.hash, fanout,
630 path);
631 ret = fn(&l->key_oid, &l->val_oid, path,
632 cb_data);
633 break;
635 if (ret)
636 return ret;
638 return 0;
641 struct tree_write_stack {
642 struct tree_write_stack *next;
643 struct strbuf buf;
644 char path[2]; /* path to subtree in next, if any */
647 static inline int matches_tree_write_stack(struct tree_write_stack *tws,
648 const char *full_path)
650 return full_path[0] == tws->path[0] &&
651 full_path[1] == tws->path[1] &&
652 full_path[2] == '/';
655 static void write_tree_entry(struct strbuf *buf, unsigned int mode,
656 const char *path, unsigned int path_len, const
657 unsigned char *sha1)
659 strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
660 strbuf_add(buf, sha1, GIT_SHA1_RAWSZ);
663 static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
664 const char *path)
666 struct tree_write_stack *n;
667 assert(!tws->next);
668 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
669 n = (struct tree_write_stack *)
670 xmalloc(sizeof(struct tree_write_stack));
671 n->next = NULL;
672 strbuf_init(&n->buf, 256 * (32 + GIT_SHA1_HEXSZ)); /* assume 256 entries per tree */
673 n->path[0] = n->path[1] = '\0';
674 tws->next = n;
675 tws->path[0] = path[0];
676 tws->path[1] = path[1];
679 static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
681 int ret;
682 struct tree_write_stack *n = tws->next;
683 struct object_id s;
684 if (n) {
685 ret = tree_write_stack_finish_subtree(n);
686 if (ret)
687 return ret;
688 ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s.hash);
689 if (ret)
690 return ret;
691 strbuf_release(&n->buf);
692 free(n);
693 tws->next = NULL;
694 write_tree_entry(&tws->buf, 040000, tws->path, 2, s.hash);
695 tws->path[0] = tws->path[1] = '\0';
697 return 0;
700 static int write_each_note_helper(struct tree_write_stack *tws,
701 const char *path, unsigned int mode,
702 const struct object_id *oid)
704 size_t path_len = strlen(path);
705 unsigned int n = 0;
706 int ret;
708 /* Determine common part of tree write stack */
709 while (tws && 3 * n < path_len &&
710 matches_tree_write_stack(tws, path + 3 * n)) {
711 n++;
712 tws = tws->next;
715 /* tws point to last matching tree_write_stack entry */
716 ret = tree_write_stack_finish_subtree(tws);
717 if (ret)
718 return ret;
720 /* Start subtrees needed to satisfy path */
721 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
722 tree_write_stack_init_subtree(tws, path + 3 * n);
723 n++;
724 tws = tws->next;
727 /* There should be no more directory components in the given path */
728 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
730 /* Finally add given entry to the current tree object */
731 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
732 oid->hash);
734 return 0;
737 struct write_each_note_data {
738 struct tree_write_stack *root;
739 struct non_note *next_non_note;
742 static int write_each_non_note_until(const char *note_path,
743 struct write_each_note_data *d)
745 struct non_note *n = d->next_non_note;
746 int cmp = 0, ret;
747 while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
748 if (note_path && cmp == 0)
749 ; /* do nothing, prefer note to non-note */
750 else {
751 ret = write_each_note_helper(d->root, n->path, n->mode,
752 &n->oid);
753 if (ret)
754 return ret;
756 n = n->next;
758 d->next_non_note = n;
759 return 0;
762 static int write_each_note(const struct object_id *object_oid,
763 const struct object_id *note_oid, char *note_path,
764 void *cb_data)
766 struct write_each_note_data *d =
767 (struct write_each_note_data *) cb_data;
768 size_t note_path_len = strlen(note_path);
769 unsigned int mode = 0100644;
771 if (note_path[note_path_len - 1] == '/') {
772 /* subtree entry */
773 note_path_len--;
774 note_path[note_path_len] = '\0';
775 mode = 040000;
777 assert(note_path_len <= GIT_SHA1_HEXSZ + FANOUT_PATH_SEPARATORS);
779 /* Weave non-note entries into note entries */
780 return write_each_non_note_until(note_path, d) ||
781 write_each_note_helper(d->root, note_path, mode, note_oid);
784 struct note_delete_list {
785 struct note_delete_list *next;
786 const unsigned char *sha1;
789 static int prune_notes_helper(const struct object_id *object_oid,
790 const struct object_id *note_oid, char *note_path,
791 void *cb_data)
793 struct note_delete_list **l = (struct note_delete_list **) cb_data;
794 struct note_delete_list *n;
796 if (has_object_file(object_oid))
797 return 0; /* nothing to do for this note */
799 /* failed to find object => prune this note */
800 n = (struct note_delete_list *) xmalloc(sizeof(*n));
801 n->next = *l;
802 n->sha1 = object_oid->hash;
803 *l = n;
804 return 0;
807 int combine_notes_concatenate(unsigned char *cur_sha1,
808 const unsigned char *new_sha1)
810 char *cur_msg = NULL, *new_msg = NULL, *buf;
811 unsigned long cur_len, new_len, buf_len;
812 enum object_type cur_type, new_type;
813 int ret;
815 /* read in both note blob objects */
816 if (!is_null_sha1(new_sha1))
817 new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
818 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
819 free(new_msg);
820 return 0;
822 if (!is_null_sha1(cur_sha1))
823 cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
824 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
825 free(cur_msg);
826 free(new_msg);
827 hashcpy(cur_sha1, new_sha1);
828 return 0;
831 /* we will separate the notes by two newlines anyway */
832 if (cur_msg[cur_len - 1] == '\n')
833 cur_len--;
835 /* concatenate cur_msg and new_msg into buf */
836 buf_len = cur_len + 2 + new_len;
837 buf = (char *) xmalloc(buf_len);
838 memcpy(buf, cur_msg, cur_len);
839 buf[cur_len] = '\n';
840 buf[cur_len + 1] = '\n';
841 memcpy(buf + cur_len + 2, new_msg, new_len);
842 free(cur_msg);
843 free(new_msg);
845 /* create a new blob object from buf */
846 ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
847 free(buf);
848 return ret;
851 int combine_notes_overwrite(unsigned char *cur_sha1,
852 const unsigned char *new_sha1)
854 hashcpy(cur_sha1, new_sha1);
855 return 0;
858 int combine_notes_ignore(unsigned char *cur_sha1,
859 const unsigned char *new_sha1)
861 return 0;
865 * Add the lines from the named object to list, with trailing
866 * newlines removed.
868 static int string_list_add_note_lines(struct string_list *list,
869 const unsigned char *sha1)
871 char *data;
872 unsigned long len;
873 enum object_type t;
875 if (is_null_sha1(sha1))
876 return 0;
878 /* read_sha1_file NUL-terminates */
879 data = read_sha1_file(sha1, &t, &len);
880 if (t != OBJ_BLOB || !data || !len) {
881 free(data);
882 return t != OBJ_BLOB || !data;
886 * If the last line of the file is EOL-terminated, this will
887 * add an empty string to the list. But it will be removed
888 * later, along with any empty strings that came from empty
889 * lines within the file.
891 string_list_split(list, data, '\n', -1);
892 free(data);
893 return 0;
896 static int string_list_join_lines_helper(struct string_list_item *item,
897 void *cb_data)
899 struct strbuf *buf = cb_data;
900 strbuf_addstr(buf, item->string);
901 strbuf_addch(buf, '\n');
902 return 0;
905 int combine_notes_cat_sort_uniq(unsigned char *cur_sha1,
906 const unsigned char *new_sha1)
908 struct string_list sort_uniq_list = STRING_LIST_INIT_DUP;
909 struct strbuf buf = STRBUF_INIT;
910 int ret = 1;
912 /* read both note blob objects into unique_lines */
913 if (string_list_add_note_lines(&sort_uniq_list, cur_sha1))
914 goto out;
915 if (string_list_add_note_lines(&sort_uniq_list, new_sha1))
916 goto out;
917 string_list_remove_empty_items(&sort_uniq_list, 0);
918 string_list_sort(&sort_uniq_list);
919 string_list_remove_duplicates(&sort_uniq_list, 0);
921 /* create a new blob object from sort_uniq_list */
922 if (for_each_string_list(&sort_uniq_list,
923 string_list_join_lines_helper, &buf))
924 goto out;
926 ret = write_sha1_file(buf.buf, buf.len, blob_type, cur_sha1);
928 out:
929 strbuf_release(&buf);
930 string_list_clear(&sort_uniq_list, 0);
931 return ret;
934 static int string_list_add_one_ref(const char *refname, const struct object_id *oid,
935 int flag, void *cb)
937 struct string_list *refs = cb;
938 if (!unsorted_string_list_has_string(refs, refname))
939 string_list_append(refs, refname);
940 return 0;
944 * The list argument must have strdup_strings set on it.
946 void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
948 assert(list->strdup_strings);
949 if (has_glob_specials(glob)) {
950 for_each_glob_ref(string_list_add_one_ref, glob, list);
951 } else {
952 struct object_id oid;
953 if (get_oid(glob, &oid))
954 warning("notes ref %s is invalid", glob);
955 if (!unsorted_string_list_has_string(list, glob))
956 string_list_append(list, glob);
960 void string_list_add_refs_from_colon_sep(struct string_list *list,
961 const char *globs)
963 struct string_list split = STRING_LIST_INIT_NODUP;
964 char *globs_copy = xstrdup(globs);
965 int i;
967 string_list_split_in_place(&split, globs_copy, ':', -1);
968 string_list_remove_empty_items(&split, 0);
970 for (i = 0; i < split.nr; i++)
971 string_list_add_refs_by_glob(list, split.items[i].string);
973 string_list_clear(&split, 0);
974 free(globs_copy);
977 static int notes_display_config(const char *k, const char *v, void *cb)
979 int *load_refs = cb;
981 if (*load_refs && !strcmp(k, "notes.displayref")) {
982 if (!v)
983 config_error_nonbool(k);
984 string_list_add_refs_by_glob(&display_notes_refs, v);
987 return 0;
990 const char *default_notes_ref(void)
992 const char *notes_ref = NULL;
993 if (!notes_ref)
994 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
995 if (!notes_ref)
996 notes_ref = notes_ref_name; /* value of core.notesRef config */
997 if (!notes_ref)
998 notes_ref = GIT_NOTES_DEFAULT_REF;
999 return notes_ref;
1002 void init_notes(struct notes_tree *t, const char *notes_ref,
1003 combine_notes_fn combine_notes, int flags)
1005 struct object_id oid, object_oid;
1006 unsigned mode;
1007 struct leaf_node root_tree;
1009 if (!t)
1010 t = &default_notes_tree;
1011 assert(!t->initialized);
1013 if (!notes_ref)
1014 notes_ref = default_notes_ref();
1016 if (!combine_notes)
1017 combine_notes = combine_notes_concatenate;
1019 t->root = (struct int_node *) xcalloc(1, sizeof(struct int_node));
1020 t->first_non_note = NULL;
1021 t->prev_non_note = NULL;
1022 t->ref = xstrdup_or_null(notes_ref);
1023 t->update_ref = (flags & NOTES_INIT_WRITABLE) ? t->ref : NULL;
1024 t->combine_notes = combine_notes;
1025 t->initialized = 1;
1026 t->dirty = 0;
1028 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
1029 get_oid_treeish(notes_ref, &object_oid))
1030 return;
1031 if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, object_oid.hash))
1032 die("Cannot use notes ref %s", notes_ref);
1033 if (get_tree_entry(object_oid.hash, "", oid.hash, &mode))
1034 die("Failed to read notes tree referenced by %s (%s)",
1035 notes_ref, oid_to_hex(&object_oid));
1037 oidclr(&root_tree.key_oid);
1038 oidcpy(&root_tree.val_oid, &oid);
1039 load_subtree(t, &root_tree, t->root, 0);
1042 struct notes_tree **load_notes_trees(struct string_list *refs, int flags)
1044 struct string_list_item *item;
1045 int counter = 0;
1046 struct notes_tree **trees;
1047 ALLOC_ARRAY(trees, refs->nr + 1);
1048 for_each_string_list_item(item, refs) {
1049 struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
1050 init_notes(t, item->string, combine_notes_ignore, flags);
1051 trees[counter++] = t;
1053 trees[counter] = NULL;
1054 return trees;
1057 void init_display_notes(struct display_notes_opt *opt)
1059 char *display_ref_env;
1060 int load_config_refs = 0;
1061 display_notes_refs.strdup_strings = 1;
1063 assert(!display_notes_trees);
1065 if (!opt || opt->use_default_notes > 0 ||
1066 (opt->use_default_notes == -1 && !opt->extra_notes_refs.nr)) {
1067 string_list_append(&display_notes_refs, default_notes_ref());
1068 display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
1069 if (display_ref_env) {
1070 string_list_add_refs_from_colon_sep(&display_notes_refs,
1071 display_ref_env);
1072 load_config_refs = 0;
1073 } else
1074 load_config_refs = 1;
1077 git_config(notes_display_config, &load_config_refs);
1079 if (opt) {
1080 struct string_list_item *item;
1081 for_each_string_list_item(item, &opt->extra_notes_refs)
1082 string_list_add_refs_by_glob(&display_notes_refs,
1083 item->string);
1086 display_notes_trees = load_notes_trees(&display_notes_refs, 0);
1087 string_list_clear(&display_notes_refs, 0);
1090 int add_note(struct notes_tree *t, const struct object_id *object_oid,
1091 const struct object_id *note_oid, combine_notes_fn combine_notes)
1093 struct leaf_node *l;
1095 if (!t)
1096 t = &default_notes_tree;
1097 assert(t->initialized);
1098 t->dirty = 1;
1099 if (!combine_notes)
1100 combine_notes = t->combine_notes;
1101 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
1102 oidcpy(&l->key_oid, object_oid);
1103 oidcpy(&l->val_oid, note_oid);
1104 return note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
1107 int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1109 struct leaf_node l;
1111 if (!t)
1112 t = &default_notes_tree;
1113 assert(t->initialized);
1114 hashcpy(l.key_oid.hash, object_sha1);
1115 oidclr(&l.val_oid);
1116 note_tree_remove(t, t->root, 0, &l);
1117 if (is_null_oid(&l.val_oid)) /* no note was removed */
1118 return 1;
1119 t->dirty = 1;
1120 return 0;
1123 const struct object_id *get_note(struct notes_tree *t,
1124 const struct object_id *oid)
1126 struct leaf_node *found;
1128 if (!t)
1129 t = &default_notes_tree;
1130 assert(t->initialized);
1131 found = note_tree_find(t, t->root, 0, oid->hash);
1132 return found ? &found->val_oid : NULL;
1135 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
1136 void *cb_data)
1138 if (!t)
1139 t = &default_notes_tree;
1140 assert(t->initialized);
1141 return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
1144 int write_notes_tree(struct notes_tree *t, unsigned char *result)
1146 struct tree_write_stack root;
1147 struct write_each_note_data cb_data;
1148 int ret;
1150 if (!t)
1151 t = &default_notes_tree;
1152 assert(t->initialized);
1154 /* Prepare for traversal of current notes tree */
1155 root.next = NULL; /* last forward entry in list is grounded */
1156 strbuf_init(&root.buf, 256 * (32 + GIT_SHA1_HEXSZ)); /* assume 256 entries */
1157 root.path[0] = root.path[1] = '\0';
1158 cb_data.root = &root;
1159 cb_data.next_non_note = t->first_non_note;
1161 /* Write tree objects representing current notes tree */
1162 ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
1163 FOR_EACH_NOTE_YIELD_SUBTREES,
1164 write_each_note, &cb_data) ||
1165 write_each_non_note_until(NULL, &cb_data) ||
1166 tree_write_stack_finish_subtree(&root) ||
1167 write_sha1_file(root.buf.buf, root.buf.len, tree_type, result);
1168 strbuf_release(&root.buf);
1169 return ret;
1172 void prune_notes(struct notes_tree *t, int flags)
1174 struct note_delete_list *l = NULL;
1176 if (!t)
1177 t = &default_notes_tree;
1178 assert(t->initialized);
1180 for_each_note(t, 0, prune_notes_helper, &l);
1182 while (l) {
1183 if (flags & NOTES_PRUNE_VERBOSE)
1184 printf("%s\n", sha1_to_hex(l->sha1));
1185 if (!(flags & NOTES_PRUNE_DRYRUN))
1186 remove_note(t, l->sha1);
1187 l = l->next;
1191 void free_notes(struct notes_tree *t)
1193 if (!t)
1194 t = &default_notes_tree;
1195 if (t->root)
1196 note_tree_free(t->root);
1197 free(t->root);
1198 while (t->first_non_note) {
1199 t->prev_non_note = t->first_non_note->next;
1200 free(t->first_non_note->path);
1201 free(t->first_non_note);
1202 t->first_non_note = t->prev_non_note;
1204 free(t->ref);
1205 memset(t, 0, sizeof(struct notes_tree));
1209 * Fill the given strbuf with the notes associated with the given object.
1211 * If the given notes_tree structure is not initialized, it will be auto-
1212 * initialized to the default value (see documentation for init_notes() above).
1213 * If the given notes_tree is NULL, the internal/default notes_tree will be
1214 * used instead.
1216 * (raw != 0) gives the %N userformat; otherwise, the note message is given
1217 * for human consumption.
1219 static void format_note(struct notes_tree *t, const struct object_id *object_oid,
1220 struct strbuf *sb, const char *output_encoding, int raw)
1222 static const char utf8[] = "utf-8";
1223 const struct object_id *oid;
1224 char *msg, *msg_p;
1225 unsigned long linelen, msglen;
1226 enum object_type type;
1228 if (!t)
1229 t = &default_notes_tree;
1230 if (!t->initialized)
1231 init_notes(t, NULL, NULL, 0);
1233 oid = get_note(t, object_oid);
1234 if (!oid)
1235 return;
1237 if (!(msg = read_sha1_file(oid->hash, &type, &msglen)) || type != OBJ_BLOB) {
1238 free(msg);
1239 return;
1242 if (output_encoding && *output_encoding &&
1243 !is_encoding_utf8(output_encoding)) {
1244 char *reencoded = reencode_string(msg, output_encoding, utf8);
1245 if (reencoded) {
1246 free(msg);
1247 msg = reencoded;
1248 msglen = strlen(msg);
1252 /* we will end the annotation by a newline anyway */
1253 if (msglen && msg[msglen - 1] == '\n')
1254 msglen--;
1256 if (!raw) {
1257 const char *ref = t->ref;
1258 if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
1259 strbuf_addstr(sb, "\nNotes:\n");
1260 } else {
1261 if (starts_with(ref, "refs/"))
1262 ref += 5;
1263 if (starts_with(ref, "notes/"))
1264 ref += 6;
1265 strbuf_addf(sb, "\nNotes (%s):\n", ref);
1269 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
1270 linelen = strchrnul(msg_p, '\n') - msg_p;
1272 if (!raw)
1273 strbuf_addstr(sb, " ");
1274 strbuf_add(sb, msg_p, linelen);
1275 strbuf_addch(sb, '\n');
1278 free(msg);
1281 void format_display_notes(const struct object_id *object_oid,
1282 struct strbuf *sb, const char *output_encoding, int raw)
1284 int i;
1285 assert(display_notes_trees);
1286 for (i = 0; display_notes_trees[i]; i++)
1287 format_note(display_notes_trees[i], object_oid, sb,
1288 output_encoding, raw);
1291 int copy_note(struct notes_tree *t,
1292 const struct object_id *from_obj, const struct object_id *to_obj,
1293 int force, combine_notes_fn combine_notes)
1295 const struct object_id *note = get_note(t, from_obj);
1296 const struct object_id *existing_note = get_note(t, to_obj);
1298 if (!force && existing_note)
1299 return 1;
1301 if (note)
1302 return add_note(t, to_obj, note, combine_notes);
1303 else if (existing_note)
1304 return add_note(t, to_obj, &null_oid, combine_notes);
1306 return 0;
1309 void expand_notes_ref(struct strbuf *sb)
1311 if (starts_with(sb->buf, "refs/notes/"))
1312 return; /* we're happy */
1313 else if (starts_with(sb->buf, "notes/"))
1314 strbuf_insert(sb, 0, "refs/", 5);
1315 else
1316 strbuf_insert(sb, 0, "refs/notes/", 11);
1319 void expand_loose_notes_ref(struct strbuf *sb)
1321 struct object_id object;
1323 if (get_oid(sb->buf, &object)) {
1324 /* fallback to expand_notes_ref */
1325 expand_notes_ref(sb);