Start preparing for 1.8.4.2
[alt-git.git] / notes.c
blobb69c0b82577e0d4958ddf3efbb4aec5a9c5fa99e
1 #include "cache.h"
2 #include "notes.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "utf8.h"
6 #include "strbuf.h"
7 #include "tree-walk.h"
8 #include "string-list.h"
9 #include "refs.h"
12 * Use a non-balancing simple 16-tree structure with struct int_node as
13 * internal nodes, and struct leaf_node as leaf nodes. Each int_node has a
14 * 16-array of pointers to its children.
15 * The bottom 2 bits of each pointer is used to identify the pointer type
16 * - ptr & 3 == 0 - NULL pointer, assert(ptr == NULL)
17 * - ptr & 3 == 1 - pointer to next internal node - cast to struct int_node *
18 * - ptr & 3 == 2 - pointer to note entry - cast to struct leaf_node *
19 * - ptr & 3 == 3 - pointer to subtree entry - cast to struct leaf_node *
21 * The root node is a statically allocated struct int_node.
23 struct int_node {
24 void *a[16];
28 * Leaf nodes come in two variants, note entries and subtree entries,
29 * distinguished by the LSb of the leaf node pointer (see above).
30 * As a note entry, the key is the SHA1 of the referenced object, and the
31 * value is the SHA1 of the note object.
32 * As a subtree entry, the key is the prefix SHA1 (w/trailing NULs) of the
33 * referenced object, using the last byte of the key to store the length of
34 * the prefix. The value is the SHA1 of the tree object containing the notes
35 * subtree.
37 struct leaf_node {
38 unsigned char key_sha1[20];
39 unsigned char val_sha1[20];
43 * A notes tree may contain entries that are not notes, and that do not follow
44 * the naming conventions of notes. There are typically none/few of these, but
45 * we still need to keep track of them. Keep a simple linked list sorted alpha-
46 * betically on the non-note path. The list is populated when parsing tree
47 * objects in load_subtree(), and the non-notes are correctly written back into
48 * the tree objects produced by write_notes_tree().
50 struct non_note {
51 struct non_note *next; /* grounded (last->next == NULL) */
52 char *path;
53 unsigned int mode;
54 unsigned char sha1[20];
57 #define PTR_TYPE_NULL 0
58 #define PTR_TYPE_INTERNAL 1
59 #define PTR_TYPE_NOTE 2
60 #define PTR_TYPE_SUBTREE 3
62 #define GET_PTR_TYPE(ptr) ((uintptr_t) (ptr) & 3)
63 #define CLR_PTR_TYPE(ptr) ((void *) ((uintptr_t) (ptr) & ~3))
64 #define SET_PTR_TYPE(ptr, type) ((void *) ((uintptr_t) (ptr) | (type)))
66 #define GET_NIBBLE(n, sha1) (((sha1[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f)
68 #define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
69 (memcmp(key_sha1, subtree_sha1, subtree_sha1[19]))
71 struct notes_tree default_notes_tree;
73 static struct string_list display_notes_refs;
74 static struct notes_tree **display_notes_trees;
76 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
77 struct int_node *node, unsigned int n);
80 * Search the tree until the appropriate location for the given key is found:
81 * 1. Start at the root node, with n = 0
82 * 2. If a[0] at the current level is a matching subtree entry, unpack that
83 * subtree entry and remove it; restart search at the current level.
84 * 3. Use the nth nibble of the key as an index into a:
85 * - If a[n] is an int_node, recurse from #2 into that node and increment n
86 * - If a matching subtree entry, unpack that subtree entry (and remove it);
87 * restart search at the current level.
88 * - Otherwise, we have found one of the following:
89 * - a subtree entry which does not match the key
90 * - a note entry which may or may not match the key
91 * - an unused leaf node (NULL)
92 * In any case, set *tree and *n, and return pointer to the tree location.
94 static void **note_tree_search(struct notes_tree *t, struct int_node **tree,
95 unsigned char *n, const unsigned char *key_sha1)
97 struct leaf_node *l;
98 unsigned char i;
99 void *p = (*tree)->a[0];
101 if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) {
102 l = (struct leaf_node *) CLR_PTR_TYPE(p);
103 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
104 /* unpack tree and resume search */
105 (*tree)->a[0] = NULL;
106 load_subtree(t, l, *tree, *n);
107 free(l);
108 return note_tree_search(t, tree, n, key_sha1);
112 i = GET_NIBBLE(*n, key_sha1);
113 p = (*tree)->a[i];
114 switch (GET_PTR_TYPE(p)) {
115 case PTR_TYPE_INTERNAL:
116 *tree = CLR_PTR_TYPE(p);
117 (*n)++;
118 return note_tree_search(t, tree, n, key_sha1);
119 case PTR_TYPE_SUBTREE:
120 l = (struct leaf_node *) CLR_PTR_TYPE(p);
121 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
122 /* unpack tree and resume search */
123 (*tree)->a[i] = NULL;
124 load_subtree(t, l, *tree, *n);
125 free(l);
126 return note_tree_search(t, tree, n, key_sha1);
128 /* fall through */
129 default:
130 return &((*tree)->a[i]);
135 * To find a leaf_node:
136 * Search to the tree location appropriate for the given key:
137 * If a note entry with matching key, return the note entry, else return NULL.
139 static struct leaf_node *note_tree_find(struct notes_tree *t,
140 struct int_node *tree, unsigned char n,
141 const unsigned char *key_sha1)
143 void **p = note_tree_search(t, &tree, &n, key_sha1);
144 if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) {
145 struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p);
146 if (!hashcmp(key_sha1, l->key_sha1))
147 return l;
149 return NULL;
153 * How to consolidate an int_node:
154 * If there are > 1 non-NULL entries, give up and return non-zero.
155 * Otherwise replace the int_node at the given index in the given parent node
156 * with the only entry (or a NULL entry if no entries) from the given tree,
157 * and return 0.
159 static int note_tree_consolidate(struct int_node *tree,
160 struct int_node *parent, unsigned char index)
162 unsigned int i;
163 void *p = NULL;
165 assert(tree && parent);
166 assert(CLR_PTR_TYPE(parent->a[index]) == tree);
168 for (i = 0; i < 16; i++) {
169 if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) {
170 if (p) /* more than one entry */
171 return -2;
172 p = tree->a[i];
176 /* replace tree with p in parent[index] */
177 parent->a[index] = p;
178 free(tree);
179 return 0;
183 * To remove a leaf_node:
184 * Search to the tree location appropriate for the given leaf_node's key:
185 * - If location does not hold a matching entry, abort and do nothing.
186 * - Copy the matching entry's value into the given entry.
187 * - Replace the matching leaf_node with a NULL entry (and free the leaf_node).
188 * - Consolidate int_nodes repeatedly, while walking up the tree towards root.
190 static void note_tree_remove(struct notes_tree *t,
191 struct int_node *tree, unsigned char n,
192 struct leaf_node *entry)
194 struct leaf_node *l;
195 struct int_node *parent_stack[20];
196 unsigned char i, j;
197 void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
199 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
200 if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
201 return; /* type mismatch, nothing to remove */
202 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
203 if (hashcmp(l->key_sha1, entry->key_sha1))
204 return; /* key mismatch, nothing to remove */
206 /* we have found a matching entry */
207 hashcpy(entry->val_sha1, l->val_sha1);
208 free(l);
209 *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
211 /* consolidate this tree level, and parent levels, if possible */
212 if (!n)
213 return; /* cannot consolidate top level */
214 /* first, build stack of ancestors between root and current node */
215 parent_stack[0] = t->root;
216 for (i = 0; i < n; i++) {
217 j = GET_NIBBLE(i, entry->key_sha1);
218 parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]);
220 assert(i == n && parent_stack[i] == tree);
221 /* next, unwind stack until note_tree_consolidate() is done */
222 while (i > 0 &&
223 !note_tree_consolidate(parent_stack[i], parent_stack[i - 1],
224 GET_NIBBLE(i - 1, entry->key_sha1)))
225 i--;
229 * To insert a leaf_node:
230 * Search to the tree location appropriate for the given leaf_node's key:
231 * - If location is unused (NULL), store the tweaked pointer directly there
232 * - If location holds a note entry that matches the note-to-be-inserted, then
233 * combine the two notes (by calling the given combine_notes function).
234 * - If location holds a note entry that matches the subtree-to-be-inserted,
235 * then unpack the subtree-to-be-inserted into the location.
236 * - If location holds a matching subtree entry, unpack the subtree at that
237 * location, and restart the insert operation from that level.
238 * - Else, create a new int_node, holding both the node-at-location and the
239 * node-to-be-inserted, and store the new int_node into the location.
241 static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
242 unsigned char n, struct leaf_node *entry, unsigned char type,
243 combine_notes_fn combine_notes)
245 struct int_node *new_node;
246 struct leaf_node *l;
247 void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
248 int ret = 0;
250 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
251 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
252 switch (GET_PTR_TYPE(*p)) {
253 case PTR_TYPE_NULL:
254 assert(!*p);
255 if (is_null_sha1(entry->val_sha1))
256 free(entry);
257 else
258 *p = SET_PTR_TYPE(entry, type);
259 return 0;
260 case PTR_TYPE_NOTE:
261 switch (type) {
262 case PTR_TYPE_NOTE:
263 if (!hashcmp(l->key_sha1, entry->key_sha1)) {
264 /* skip concatenation if l == entry */
265 if (!hashcmp(l->val_sha1, entry->val_sha1))
266 return 0;
268 ret = combine_notes(l->val_sha1,
269 entry->val_sha1);
270 if (!ret && is_null_sha1(l->val_sha1))
271 note_tree_remove(t, tree, n, entry);
272 free(entry);
273 return ret;
275 break;
276 case PTR_TYPE_SUBTREE:
277 if (!SUBTREE_SHA1_PREFIXCMP(l->key_sha1,
278 entry->key_sha1)) {
279 /* unpack 'entry' */
280 load_subtree(t, entry, tree, n);
281 free(entry);
282 return 0;
284 break;
286 break;
287 case PTR_TYPE_SUBTREE:
288 if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) {
289 /* unpack 'l' and restart insert */
290 *p = NULL;
291 load_subtree(t, l, tree, n);
292 free(l);
293 return note_tree_insert(t, tree, n, entry, type,
294 combine_notes);
296 break;
299 /* non-matching leaf_node */
300 assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
301 GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
302 if (is_null_sha1(entry->val_sha1)) { /* skip insertion of empty note */
303 free(entry);
304 return 0;
306 new_node = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
307 ret = note_tree_insert(t, new_node, n + 1, l, GET_PTR_TYPE(*p),
308 combine_notes);
309 if (ret)
310 return ret;
311 *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
312 return note_tree_insert(t, new_node, n + 1, entry, type, combine_notes);
315 /* Free the entire notes data contained in the given tree */
316 static void note_tree_free(struct int_node *tree)
318 unsigned int i;
319 for (i = 0; i < 16; i++) {
320 void *p = tree->a[i];
321 switch (GET_PTR_TYPE(p)) {
322 case PTR_TYPE_INTERNAL:
323 note_tree_free(CLR_PTR_TYPE(p));
324 /* fall through */
325 case PTR_TYPE_NOTE:
326 case PTR_TYPE_SUBTREE:
327 free(CLR_PTR_TYPE(p));
333 * Convert a partial SHA1 hex string to the corresponding partial SHA1 value.
334 * - hex - Partial SHA1 segment in ASCII hex format
335 * - hex_len - Length of above segment. Must be multiple of 2 between 0 and 40
336 * - sha1 - Partial SHA1 value is written here
337 * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20
338 * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format)).
339 * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2).
340 * Pads sha1 with NULs up to sha1_len (not included in returned length).
342 static int get_sha1_hex_segment(const char *hex, unsigned int hex_len,
343 unsigned char *sha1, unsigned int sha1_len)
345 unsigned int i, len = hex_len >> 1;
346 if (hex_len % 2 != 0 || len > sha1_len)
347 return -1;
348 for (i = 0; i < len; i++) {
349 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
350 if (val & ~0xff)
351 return -1;
352 *sha1++ = val;
353 hex += 2;
355 for (; i < sha1_len; i++)
356 *sha1++ = 0;
357 return len;
360 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
362 return strcmp(a->path, b->path);
365 static void add_non_note(struct notes_tree *t, const char *path,
366 unsigned int mode, const unsigned char *sha1)
368 struct non_note *p = t->prev_non_note, *n;
369 n = (struct non_note *) xmalloc(sizeof(struct non_note));
370 n->next = NULL;
371 n->path = xstrdup(path);
372 n->mode = mode;
373 hashcpy(n->sha1, sha1);
374 t->prev_non_note = n;
376 if (!t->first_non_note) {
377 t->first_non_note = n;
378 return;
381 if (non_note_cmp(p, n) < 0)
382 ; /* do nothing */
383 else if (non_note_cmp(t->first_non_note, n) <= 0)
384 p = t->first_non_note;
385 else {
386 /* n sorts before t->first_non_note */
387 n->next = t->first_non_note;
388 t->first_non_note = n;
389 return;
392 /* n sorts equal or after p */
393 while (p->next && non_note_cmp(p->next, n) <= 0)
394 p = p->next;
396 if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
397 assert(strcmp(p->path, n->path) == 0);
398 p->mode = n->mode;
399 hashcpy(p->sha1, n->sha1);
400 free(n);
401 t->prev_non_note = p;
402 return;
405 /* n sorts between p and p->next */
406 n->next = p->next;
407 p->next = n;
410 static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
411 struct int_node *node, unsigned int n)
413 unsigned char object_sha1[20];
414 unsigned int prefix_len;
415 void *buf;
416 struct tree_desc desc;
417 struct name_entry entry;
418 int len, path_len;
419 unsigned char type;
420 struct leaf_node *l;
422 buf = fill_tree_descriptor(&desc, subtree->val_sha1);
423 if (!buf)
424 die("Could not read %s for notes-index",
425 sha1_to_hex(subtree->val_sha1));
427 prefix_len = subtree->key_sha1[19];
428 assert(prefix_len * 2 >= n);
429 memcpy(object_sha1, subtree->key_sha1, prefix_len);
430 while (tree_entry(&desc, &entry)) {
431 path_len = strlen(entry.path);
432 len = get_sha1_hex_segment(entry.path, path_len,
433 object_sha1 + prefix_len, 20 - prefix_len);
434 if (len < 0)
435 goto handle_non_note; /* entry.path is not a SHA1 */
436 len += prefix_len;
439 * If object SHA1 is complete (len == 20), assume note object
440 * If object SHA1 is incomplete (len < 20), and current
441 * component consists of 2 hex chars, assume note subtree
443 if (len <= 20) {
444 type = PTR_TYPE_NOTE;
445 l = (struct leaf_node *)
446 xcalloc(sizeof(struct leaf_node), 1);
447 hashcpy(l->key_sha1, object_sha1);
448 hashcpy(l->val_sha1, entry.sha1);
449 if (len < 20) {
450 if (!S_ISDIR(entry.mode) || path_len != 2)
451 goto handle_non_note; /* not subtree */
452 l->key_sha1[19] = (unsigned char) len;
453 type = PTR_TYPE_SUBTREE;
455 if (note_tree_insert(t, node, n, l, type,
456 combine_notes_concatenate))
457 die("Failed to load %s %s into notes tree "
458 "from %s",
459 type == PTR_TYPE_NOTE ? "note" : "subtree",
460 sha1_to_hex(l->key_sha1), t->ref);
462 continue;
464 handle_non_note:
466 * Determine full path for this non-note entry:
467 * The filename is already found in entry.path, but the
468 * directory part of the path must be deduced from the subtree
469 * containing this entry. We assume here that the overall notes
470 * tree follows a strict byte-based progressive fanout
471 * structure (i.e. using 2/38, 2/2/36, etc. fanouts, and not
472 * e.g. 4/36 fanout). This means that if a non-note is found at
473 * path "dead/beef", the following code will register it as
474 * being found on "de/ad/beef".
475 * On the other hand, if you use such non-obvious non-note
476 * paths in the middle of a notes tree, you deserve what's
477 * coming to you ;). Note that for non-notes that are not
478 * SHA1-like at the top level, there will be no problems.
480 * To conclude, it is strongly advised to make sure non-notes
481 * have at least one non-hex character in the top-level path
482 * component.
485 char non_note_path[PATH_MAX];
486 char *p = non_note_path;
487 const char *q = sha1_to_hex(subtree->key_sha1);
488 int i;
489 for (i = 0; i < prefix_len; i++) {
490 *p++ = *q++;
491 *p++ = *q++;
492 *p++ = '/';
494 strcpy(p, entry.path);
495 add_non_note(t, non_note_path, entry.mode, entry.sha1);
498 free(buf);
502 * Determine optimal on-disk fanout for this part of the notes tree
504 * Given a (sub)tree and the level in the internal tree structure, determine
505 * whether or not the given existing fanout should be expanded for this
506 * (sub)tree.
508 * Values of the 'fanout' variable:
509 * - 0: No fanout (all notes are stored directly in the root notes tree)
510 * - 1: 2/38 fanout
511 * - 2: 2/2/36 fanout
512 * - 3: 2/2/2/34 fanout
513 * etc.
515 static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
516 unsigned char fanout)
519 * The following is a simple heuristic that works well in practice:
520 * For each even-numbered 16-tree level (remember that each on-disk
521 * fanout level corresponds to _two_ 16-tree levels), peek at all 16
522 * entries at that tree level. If all of them are either int_nodes or
523 * subtree entries, then there are likely plenty of notes below this
524 * level, so we return an incremented fanout.
526 unsigned int i;
527 if ((n % 2) || (n > 2 * fanout))
528 return fanout;
529 for (i = 0; i < 16; i++) {
530 switch (GET_PTR_TYPE(tree->a[i])) {
531 case PTR_TYPE_SUBTREE:
532 case PTR_TYPE_INTERNAL:
533 continue;
534 default:
535 return fanout;
538 return fanout + 1;
541 static void construct_path_with_fanout(const unsigned char *sha1,
542 unsigned char fanout, char *path)
544 unsigned int i = 0, j = 0;
545 const char *hex_sha1 = sha1_to_hex(sha1);
546 assert(fanout < 20);
547 while (fanout) {
548 path[i++] = hex_sha1[j++];
549 path[i++] = hex_sha1[j++];
550 path[i++] = '/';
551 fanout--;
553 strcpy(path + i, hex_sha1 + j);
556 static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
557 unsigned char n, unsigned char fanout, int flags,
558 each_note_fn fn, void *cb_data)
560 unsigned int i;
561 void *p;
562 int ret = 0;
563 struct leaf_node *l;
564 static char path[40 + 19 + 1]; /* hex SHA1 + 19 * '/' + NUL */
566 fanout = determine_fanout(tree, n, fanout);
567 for (i = 0; i < 16; i++) {
568 redo:
569 p = tree->a[i];
570 switch (GET_PTR_TYPE(p)) {
571 case PTR_TYPE_INTERNAL:
572 /* recurse into int_node */
573 ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
574 fanout, flags, fn, cb_data);
575 break;
576 case PTR_TYPE_SUBTREE:
577 l = (struct leaf_node *) CLR_PTR_TYPE(p);
579 * Subtree entries in the note tree represent parts of
580 * the note tree that have not yet been explored. There
581 * is a direct relationship between subtree entries at
582 * level 'n' in the tree, and the 'fanout' variable:
583 * Subtree entries at level 'n <= 2 * fanout' should be
584 * preserved, since they correspond exactly to a fanout
585 * directory in the on-disk structure. However, subtree
586 * entries at level 'n > 2 * fanout' should NOT be
587 * preserved, but rather consolidated into the above
588 * notes tree level. We achieve this by unconditionally
589 * unpacking subtree entries that exist below the
590 * threshold level at 'n = 2 * fanout'.
592 if (n <= 2 * fanout &&
593 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
594 /* invoke callback with subtree */
595 unsigned int path_len =
596 l->key_sha1[19] * 2 + fanout;
597 assert(path_len < 40 + 19);
598 construct_path_with_fanout(l->key_sha1, fanout,
599 path);
600 /* Create trailing slash, if needed */
601 if (path[path_len - 1] != '/')
602 path[path_len++] = '/';
603 path[path_len] = '\0';
604 ret = fn(l->key_sha1, l->val_sha1, path,
605 cb_data);
607 if (n > fanout * 2 ||
608 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
609 /* unpack subtree and resume traversal */
610 tree->a[i] = NULL;
611 load_subtree(t, l, tree, n);
612 free(l);
613 goto redo;
615 break;
616 case PTR_TYPE_NOTE:
617 l = (struct leaf_node *) CLR_PTR_TYPE(p);
618 construct_path_with_fanout(l->key_sha1, fanout, path);
619 ret = fn(l->key_sha1, l->val_sha1, path, cb_data);
620 break;
622 if (ret)
623 return ret;
625 return 0;
628 struct tree_write_stack {
629 struct tree_write_stack *next;
630 struct strbuf buf;
631 char path[2]; /* path to subtree in next, if any */
634 static inline int matches_tree_write_stack(struct tree_write_stack *tws,
635 const char *full_path)
637 return full_path[0] == tws->path[0] &&
638 full_path[1] == tws->path[1] &&
639 full_path[2] == '/';
642 static void write_tree_entry(struct strbuf *buf, unsigned int mode,
643 const char *path, unsigned int path_len, const
644 unsigned char *sha1)
646 strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
647 strbuf_add(buf, sha1, 20);
650 static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
651 const char *path)
653 struct tree_write_stack *n;
654 assert(!tws->next);
655 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
656 n = (struct tree_write_stack *)
657 xmalloc(sizeof(struct tree_write_stack));
658 n->next = NULL;
659 strbuf_init(&n->buf, 256 * (32 + 40)); /* assume 256 entries per tree */
660 n->path[0] = n->path[1] = '\0';
661 tws->next = n;
662 tws->path[0] = path[0];
663 tws->path[1] = path[1];
666 static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
668 int ret;
669 struct tree_write_stack *n = tws->next;
670 unsigned char s[20];
671 if (n) {
672 ret = tree_write_stack_finish_subtree(n);
673 if (ret)
674 return ret;
675 ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s);
676 if (ret)
677 return ret;
678 strbuf_release(&n->buf);
679 free(n);
680 tws->next = NULL;
681 write_tree_entry(&tws->buf, 040000, tws->path, 2, s);
682 tws->path[0] = tws->path[1] = '\0';
684 return 0;
687 static int write_each_note_helper(struct tree_write_stack *tws,
688 const char *path, unsigned int mode,
689 const unsigned char *sha1)
691 size_t path_len = strlen(path);
692 unsigned int n = 0;
693 int ret;
695 /* Determine common part of tree write stack */
696 while (tws && 3 * n < path_len &&
697 matches_tree_write_stack(tws, path + 3 * n)) {
698 n++;
699 tws = tws->next;
702 /* tws point to last matching tree_write_stack entry */
703 ret = tree_write_stack_finish_subtree(tws);
704 if (ret)
705 return ret;
707 /* Start subtrees needed to satisfy path */
708 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
709 tree_write_stack_init_subtree(tws, path + 3 * n);
710 n++;
711 tws = tws->next;
714 /* There should be no more directory components in the given path */
715 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
717 /* Finally add given entry to the current tree object */
718 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
719 sha1);
721 return 0;
724 struct write_each_note_data {
725 struct tree_write_stack *root;
726 struct non_note *next_non_note;
729 static int write_each_non_note_until(const char *note_path,
730 struct write_each_note_data *d)
732 struct non_note *n = d->next_non_note;
733 int cmp = 0, ret;
734 while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
735 if (note_path && cmp == 0)
736 ; /* do nothing, prefer note to non-note */
737 else {
738 ret = write_each_note_helper(d->root, n->path, n->mode,
739 n->sha1);
740 if (ret)
741 return ret;
743 n = n->next;
745 d->next_non_note = n;
746 return 0;
749 static int write_each_note(const unsigned char *object_sha1,
750 const unsigned char *note_sha1, char *note_path,
751 void *cb_data)
753 struct write_each_note_data *d =
754 (struct write_each_note_data *) cb_data;
755 size_t note_path_len = strlen(note_path);
756 unsigned int mode = 0100644;
758 if (note_path[note_path_len - 1] == '/') {
759 /* subtree entry */
760 note_path_len--;
761 note_path[note_path_len] = '\0';
762 mode = 040000;
764 assert(note_path_len <= 40 + 19);
766 /* Weave non-note entries into note entries */
767 return write_each_non_note_until(note_path, d) ||
768 write_each_note_helper(d->root, note_path, mode, note_sha1);
771 struct note_delete_list {
772 struct note_delete_list *next;
773 const unsigned char *sha1;
776 static int prune_notes_helper(const unsigned char *object_sha1,
777 const unsigned char *note_sha1, char *note_path,
778 void *cb_data)
780 struct note_delete_list **l = (struct note_delete_list **) cb_data;
781 struct note_delete_list *n;
783 if (has_sha1_file(object_sha1))
784 return 0; /* nothing to do for this note */
786 /* failed to find object => prune this note */
787 n = (struct note_delete_list *) xmalloc(sizeof(*n));
788 n->next = *l;
789 n->sha1 = object_sha1;
790 *l = n;
791 return 0;
794 int combine_notes_concatenate(unsigned char *cur_sha1,
795 const unsigned char *new_sha1)
797 char *cur_msg = NULL, *new_msg = NULL, *buf;
798 unsigned long cur_len, new_len, buf_len;
799 enum object_type cur_type, new_type;
800 int ret;
802 /* read in both note blob objects */
803 if (!is_null_sha1(new_sha1))
804 new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
805 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
806 free(new_msg);
807 return 0;
809 if (!is_null_sha1(cur_sha1))
810 cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
811 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
812 free(cur_msg);
813 free(new_msg);
814 hashcpy(cur_sha1, new_sha1);
815 return 0;
818 /* we will separate the notes by two newlines anyway */
819 if (cur_msg[cur_len - 1] == '\n')
820 cur_len--;
822 /* concatenate cur_msg and new_msg into buf */
823 buf_len = cur_len + 2 + new_len;
824 buf = (char *) xmalloc(buf_len);
825 memcpy(buf, cur_msg, cur_len);
826 buf[cur_len] = '\n';
827 buf[cur_len + 1] = '\n';
828 memcpy(buf + cur_len + 2, new_msg, new_len);
829 free(cur_msg);
830 free(new_msg);
832 /* create a new blob object from buf */
833 ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
834 free(buf);
835 return ret;
838 int combine_notes_overwrite(unsigned char *cur_sha1,
839 const unsigned char *new_sha1)
841 hashcpy(cur_sha1, new_sha1);
842 return 0;
845 int combine_notes_ignore(unsigned char *cur_sha1,
846 const unsigned char *new_sha1)
848 return 0;
852 * Add the lines from the named object to list, with trailing
853 * newlines removed.
855 static int string_list_add_note_lines(struct string_list *list,
856 const unsigned char *sha1)
858 char *data;
859 unsigned long len;
860 enum object_type t;
862 if (is_null_sha1(sha1))
863 return 0;
865 /* read_sha1_file NUL-terminates */
866 data = read_sha1_file(sha1, &t, &len);
867 if (t != OBJ_BLOB || !data || !len) {
868 free(data);
869 return t != OBJ_BLOB || !data;
873 * If the last line of the file is EOL-terminated, this will
874 * add an empty string to the list. But it will be removed
875 * later, along with any empty strings that came from empty
876 * lines within the file.
878 string_list_split(list, data, '\n', -1);
879 free(data);
880 return 0;
883 static int string_list_join_lines_helper(struct string_list_item *item,
884 void *cb_data)
886 struct strbuf *buf = cb_data;
887 strbuf_addstr(buf, item->string);
888 strbuf_addch(buf, '\n');
889 return 0;
892 int combine_notes_cat_sort_uniq(unsigned char *cur_sha1,
893 const unsigned char *new_sha1)
895 struct string_list sort_uniq_list = STRING_LIST_INIT_DUP;
896 struct strbuf buf = STRBUF_INIT;
897 int ret = 1;
899 /* read both note blob objects into unique_lines */
900 if (string_list_add_note_lines(&sort_uniq_list, cur_sha1))
901 goto out;
902 if (string_list_add_note_lines(&sort_uniq_list, new_sha1))
903 goto out;
904 string_list_remove_empty_items(&sort_uniq_list, 0);
905 sort_string_list(&sort_uniq_list);
906 string_list_remove_duplicates(&sort_uniq_list, 0);
908 /* create a new blob object from sort_uniq_list */
909 if (for_each_string_list(&sort_uniq_list,
910 string_list_join_lines_helper, &buf))
911 goto out;
913 ret = write_sha1_file(buf.buf, buf.len, blob_type, cur_sha1);
915 out:
916 strbuf_release(&buf);
917 string_list_clear(&sort_uniq_list, 0);
918 return ret;
921 static int string_list_add_one_ref(const char *refname, const unsigned char *sha1,
922 int flag, void *cb)
924 struct string_list *refs = cb;
925 if (!unsorted_string_list_has_string(refs, refname))
926 string_list_append(refs, refname);
927 return 0;
931 * The list argument must have strdup_strings set on it.
933 void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
935 assert(list->strdup_strings);
936 if (has_glob_specials(glob)) {
937 for_each_glob_ref(string_list_add_one_ref, glob, list);
938 } else {
939 unsigned char sha1[20];
940 if (get_sha1(glob, sha1))
941 warning("notes ref %s is invalid", glob);
942 if (!unsorted_string_list_has_string(list, glob))
943 string_list_append(list, glob);
947 void string_list_add_refs_from_colon_sep(struct string_list *list,
948 const char *globs)
950 struct string_list split = STRING_LIST_INIT_NODUP;
951 char *globs_copy = xstrdup(globs);
952 int i;
954 string_list_split_in_place(&split, globs_copy, ':', -1);
955 string_list_remove_empty_items(&split, 0);
957 for (i = 0; i < split.nr; i++)
958 string_list_add_refs_by_glob(list, split.items[i].string);
960 string_list_clear(&split, 0);
961 free(globs_copy);
964 static int notes_display_config(const char *k, const char *v, void *cb)
966 int *load_refs = cb;
968 if (*load_refs && !strcmp(k, "notes.displayref")) {
969 if (!v)
970 config_error_nonbool(k);
971 string_list_add_refs_by_glob(&display_notes_refs, v);
974 return 0;
977 const char *default_notes_ref(void)
979 const char *notes_ref = NULL;
980 if (!notes_ref)
981 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
982 if (!notes_ref)
983 notes_ref = notes_ref_name; /* value of core.notesRef config */
984 if (!notes_ref)
985 notes_ref = GIT_NOTES_DEFAULT_REF;
986 return notes_ref;
989 void init_notes(struct notes_tree *t, const char *notes_ref,
990 combine_notes_fn combine_notes, int flags)
992 unsigned char sha1[20], object_sha1[20];
993 unsigned mode;
994 struct leaf_node root_tree;
996 if (!t)
997 t = &default_notes_tree;
998 assert(!t->initialized);
1000 if (!notes_ref)
1001 notes_ref = default_notes_ref();
1003 if (!combine_notes)
1004 combine_notes = combine_notes_concatenate;
1006 t->root = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
1007 t->first_non_note = NULL;
1008 t->prev_non_note = NULL;
1009 t->ref = notes_ref ? xstrdup(notes_ref) : NULL;
1010 t->combine_notes = combine_notes;
1011 t->initialized = 1;
1012 t->dirty = 0;
1014 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
1015 read_ref(notes_ref, object_sha1))
1016 return;
1017 if (get_tree_entry(object_sha1, "", sha1, &mode))
1018 die("Failed to read notes tree referenced by %s (%s)",
1019 notes_ref, sha1_to_hex(object_sha1));
1021 hashclr(root_tree.key_sha1);
1022 hashcpy(root_tree.val_sha1, sha1);
1023 load_subtree(t, &root_tree, t->root, 0);
1026 struct notes_tree **load_notes_trees(struct string_list *refs)
1028 struct string_list_item *item;
1029 int counter = 0;
1030 struct notes_tree **trees;
1031 trees = xmalloc((refs->nr+1) * sizeof(struct notes_tree *));
1032 for_each_string_list_item(item, refs) {
1033 struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
1034 init_notes(t, item->string, combine_notes_ignore, 0);
1035 trees[counter++] = t;
1037 trees[counter] = NULL;
1038 return trees;
1041 void init_display_notes(struct display_notes_opt *opt)
1043 char *display_ref_env;
1044 int load_config_refs = 0;
1045 display_notes_refs.strdup_strings = 1;
1047 assert(!display_notes_trees);
1049 if (!opt || opt->use_default_notes > 0 ||
1050 (opt->use_default_notes == -1 && !opt->extra_notes_refs.nr)) {
1051 string_list_append(&display_notes_refs, default_notes_ref());
1052 display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
1053 if (display_ref_env) {
1054 string_list_add_refs_from_colon_sep(&display_notes_refs,
1055 display_ref_env);
1056 load_config_refs = 0;
1057 } else
1058 load_config_refs = 1;
1061 git_config(notes_display_config, &load_config_refs);
1063 if (opt) {
1064 struct string_list_item *item;
1065 for_each_string_list_item(item, &opt->extra_notes_refs)
1066 string_list_add_refs_by_glob(&display_notes_refs,
1067 item->string);
1070 display_notes_trees = load_notes_trees(&display_notes_refs);
1071 string_list_clear(&display_notes_refs, 0);
1074 int add_note(struct notes_tree *t, const unsigned char *object_sha1,
1075 const unsigned char *note_sha1, combine_notes_fn combine_notes)
1077 struct leaf_node *l;
1079 if (!t)
1080 t = &default_notes_tree;
1081 assert(t->initialized);
1082 t->dirty = 1;
1083 if (!combine_notes)
1084 combine_notes = t->combine_notes;
1085 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
1086 hashcpy(l->key_sha1, object_sha1);
1087 hashcpy(l->val_sha1, note_sha1);
1088 return note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
1091 int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1093 struct leaf_node l;
1095 if (!t)
1096 t = &default_notes_tree;
1097 assert(t->initialized);
1098 hashcpy(l.key_sha1, object_sha1);
1099 hashclr(l.val_sha1);
1100 note_tree_remove(t, t->root, 0, &l);
1101 if (is_null_sha1(l.val_sha1)) /* no note was removed */
1102 return 1;
1103 t->dirty = 1;
1104 return 0;
1107 const unsigned char *get_note(struct notes_tree *t,
1108 const unsigned char *object_sha1)
1110 struct leaf_node *found;
1112 if (!t)
1113 t = &default_notes_tree;
1114 assert(t->initialized);
1115 found = note_tree_find(t, t->root, 0, object_sha1);
1116 return found ? found->val_sha1 : NULL;
1119 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
1120 void *cb_data)
1122 if (!t)
1123 t = &default_notes_tree;
1124 assert(t->initialized);
1125 return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
1128 int write_notes_tree(struct notes_tree *t, unsigned char *result)
1130 struct tree_write_stack root;
1131 struct write_each_note_data cb_data;
1132 int ret;
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 + 40)); /* 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 ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
1147 FOR_EACH_NOTE_YIELD_SUBTREES,
1148 write_each_note, &cb_data) ||
1149 write_each_non_note_until(NULL, &cb_data) ||
1150 tree_write_stack_finish_subtree(&root) ||
1151 write_sha1_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 unsigned char *object_sha1,
1204 struct strbuf *sb, const char *output_encoding, int raw)
1206 static const char utf8[] = "utf-8";
1207 const unsigned char *sha1;
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 sha1 = get_note(t, object_sha1);
1218 if (!sha1)
1219 return;
1221 if (!(msg = read_sha1_file(sha1, &type, &msglen)) || !msglen ||
1222 type != OBJ_BLOB) {
1223 free(msg);
1224 return;
1227 if (output_encoding && *output_encoding &&
1228 !is_encoding_utf8(output_encoding)) {
1229 char *reencoded = reencode_string(msg, output_encoding, utf8);
1230 if (reencoded) {
1231 free(msg);
1232 msg = reencoded;
1233 msglen = strlen(msg);
1237 /* we will end the annotation by a newline anyway */
1238 if (msglen && msg[msglen - 1] == '\n')
1239 msglen--;
1241 if (!raw) {
1242 const char *ref = t->ref;
1243 if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
1244 strbuf_addstr(sb, "\nNotes:\n");
1245 } else {
1246 if (!prefixcmp(ref, "refs/"))
1247 ref += 5;
1248 if (!prefixcmp(ref, "notes/"))
1249 ref += 6;
1250 strbuf_addf(sb, "\nNotes (%s):\n", ref);
1254 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
1255 linelen = strchrnul(msg_p, '\n') - msg_p;
1257 if (!raw)
1258 strbuf_addstr(sb, " ");
1259 strbuf_add(sb, msg_p, linelen);
1260 strbuf_addch(sb, '\n');
1263 free(msg);
1266 void format_display_notes(const unsigned char *object_sha1,
1267 struct strbuf *sb, const char *output_encoding, int raw)
1269 int i;
1270 assert(display_notes_trees);
1271 for (i = 0; display_notes_trees[i]; i++)
1272 format_note(display_notes_trees[i], object_sha1, sb,
1273 output_encoding, raw);
1276 int copy_note(struct notes_tree *t,
1277 const unsigned char *from_obj, const unsigned char *to_obj,
1278 int force, combine_notes_fn combine_notes)
1280 const unsigned char *note = get_note(t, from_obj);
1281 const unsigned char *existing_note = get_note(t, to_obj);
1283 if (!force && existing_note)
1284 return 1;
1286 if (note)
1287 return add_note(t, to_obj, note, combine_notes);
1288 else if (existing_note)
1289 return add_note(t, to_obj, null_sha1, combine_notes);
1291 return 0;
1294 void expand_notes_ref(struct strbuf *sb)
1296 if (!prefixcmp(sb->buf, "refs/notes/"))
1297 return; /* we're happy */
1298 else if (!prefixcmp(sb->buf, "notes/"))
1299 strbuf_insert(sb, 0, "refs/", 5);
1300 else
1301 strbuf_insert(sb, 0, "refs/notes/", 11);