930ae3a0d795a084f8c709249342fb719aa40046
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"
11
12/*
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 *
21 *
22 * The root node is a statically allocated struct int_node.
23 */
24struct int_node {
25 void *a[16];
26};
27
28/*
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.
37 */
38struct leaf_node {
39 struct object_id key_oid;
40 struct object_id val_oid;
41};
42
43/*
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().
50 */
51struct non_note {
52 struct non_note *next; /* grounded (last->next == NULL) */
53 char *path;
54 unsigned int mode;
55 struct object_id oid;
56};
57
58#define PTR_TYPE_NULL 0
59#define PTR_TYPE_INTERNAL 1
60#define PTR_TYPE_NOTE 2
61#define PTR_TYPE_SUBTREE 3
62
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)))
66
67#define GET_NIBBLE(n, sha1) ((((sha1)[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f)
68
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]))
73
74struct notes_tree default_notes_tree;
75
76static struct string_list display_notes_refs = STRING_LIST_INIT_NODUP;
77static struct notes_tree **display_notes_trees;
78
79static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
80 struct int_node *node, unsigned int n);
81
82/*
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.
96 */
97static void **note_tree_search(struct notes_tree *t, struct int_node **tree,
98 unsigned char *n, const unsigned char *key_sha1)
99{
100 struct leaf_node *l;
101 unsigned char i;
102 void *p = (*tree)->a[0];
103
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);
112 }
113 }
114
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);
130 }
131 /* fall through */
132 default:
133 return &((*tree)->a[i]);
134 }
135}
136
137/*
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.
141 */
142static struct leaf_node *note_tree_find(struct notes_tree *t,
143 struct int_node *tree, unsigned char n,
144 const unsigned char *key_sha1)
145{
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;
151 }
152 return NULL;
153}
154
155/*
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.
161 */
162static int note_tree_consolidate(struct int_node *tree,
163 struct int_node *parent, unsigned char index)
164{
165 unsigned int i;
166 void *p = NULL;
167
168 assert(tree && parent);
169 assert(CLR_PTR_TYPE(parent->a[index]) == tree);
170
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];
176 }
177 }
178
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;
185}
186
187/*
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.
194 */
195static void note_tree_remove(struct notes_tree *t,
196 struct int_node *tree, unsigned char n,
197 struct leaf_node *entry)
198{
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);
203
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 */
210
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);
215
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]);
224 }
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--;
231}
232
233/*
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.
245 */
246static 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)
249{
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;
254
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;
272
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;
279 }
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;
288 }
289 break;
290 }
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);
300 }
301 break;
302 }
303
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;
310 }
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);
318}
319
320/* Free the entire notes data contained in the given tree */
321static void note_tree_free(struct int_node *tree)
322{
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));
333 }
334 }
335}
336
337/*
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 * - oid - Partial SHA1 value is written here
342 * - oid_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20
343 * Return 0 on success or -1 on error (invalid arguments or input not
344 * in hex format). Pad oid with NULs up to oid_len.
345 */
346static int get_oid_hex_segment(const char *hex, unsigned int hex_len,
347 unsigned char *oid, unsigned int oid_len)
348{
349 unsigned int i, len = hex_len >> 1;
350 if (hex_len % 2 != 0 || len > oid_len)
351 return -1;
352 for (i = 0; i < len; i++) {
353 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
354 if (val & ~0xff)
355 return -1;
356 *oid++ = val;
357 hex += 2;
358 }
359 for (; i < oid_len; i++)
360 *oid++ = 0;
361 return 0;
362}
363
364static int non_note_cmp(const struct non_note *a, const struct non_note *b)
365{
366 return strcmp(a->path, b->path);
367}
368
369/* note: takes ownership of path string */
370static void add_non_note(struct notes_tree *t, char *path,
371 unsigned int mode, const unsigned char *sha1)
372{
373 struct non_note *p = t->prev_non_note, *n;
374 n = (struct non_note *) xmalloc(sizeof(struct non_note));
375 n->next = NULL;
376 n->path = path;
377 n->mode = mode;
378 hashcpy(n->oid.hash, sha1);
379 t->prev_non_note = n;
380
381 if (!t->first_non_note) {
382 t->first_non_note = n;
383 return;
384 }
385
386 if (non_note_cmp(p, n) < 0)
387 ; /* do nothing */
388 else if (non_note_cmp(t->first_non_note, n) <= 0)
389 p = t->first_non_note;
390 else {
391 /* n sorts before t->first_non_note */
392 n->next = t->first_non_note;
393 t->first_non_note = n;
394 return;
395 }
396
397 /* n sorts equal or after p */
398 while (p->next && non_note_cmp(p->next, n) <= 0)
399 p = p->next;
400
401 if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
402 assert(strcmp(p->path, n->path) == 0);
403 p->mode = n->mode;
404 oidcpy(&p->oid, &n->oid);
405 free(n);
406 t->prev_non_note = p;
407 return;
408 }
409
410 /* n sorts between p and p->next */
411 n->next = p->next;
412 p->next = n;
413}
414
415static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
416 struct int_node *node, unsigned int n)
417{
418 struct object_id object_oid;
419 unsigned int prefix_len;
420 void *buf;
421 struct tree_desc desc;
422 struct name_entry entry;
423
424 buf = fill_tree_descriptor(&desc, subtree->val_oid.hash);
425 if (!buf)
426 die("Could not read %s for notes-index",
427 oid_to_hex(&subtree->val_oid));
428
429 prefix_len = subtree->key_oid.hash[KEY_INDEX];
430 assert(prefix_len * 2 >= n);
431 memcpy(object_oid.hash, subtree->key_oid.hash, prefix_len);
432 while (tree_entry(&desc, &entry)) {
433 unsigned char type;
434 struct leaf_node *l;
435 int path_len = strlen(entry.path);
436
437 if (path_len == 2 * (GIT_SHA1_RAWSZ - prefix_len)) {
438 /* This is potentially the remainder of the SHA-1 */
439
440 if (!S_ISREG(entry.mode))
441 /* notes must be blobs */
442 goto handle_non_note;
443
444 if (get_oid_hex_segment(entry.path, path_len,
445 object_oid.hash + prefix_len,
446 GIT_SHA1_RAWSZ - prefix_len))
447 goto handle_non_note; /* entry.path is not a SHA1 */
448
449 type = PTR_TYPE_NOTE;
450 l = (struct leaf_node *)
451 xcalloc(1, sizeof(struct leaf_node));
452 oidcpy(&l->key_oid, &object_oid);
453 oidcpy(&l->val_oid, entry.oid);
454 } else if (path_len == 2) {
455 /* This is potentially an internal node */
456
457 if (!S_ISDIR(entry.mode))
458 /* internal nodes must be trees */
459 goto handle_non_note;
460
461 if (get_oid_hex_segment(entry.path, 2,
462 object_oid.hash + prefix_len,
463 GIT_SHA1_RAWSZ - prefix_len))
464 goto handle_non_note; /* entry.path is not a SHA1 */
465
466 type = PTR_TYPE_SUBTREE;
467 l = (struct leaf_node *)
468 xcalloc(1, sizeof(struct leaf_node));
469 oidcpy(&l->key_oid, &object_oid);
470 oidcpy(&l->val_oid, entry.oid);
471 l->key_oid.hash[KEY_INDEX] = (unsigned char) (prefix_len + 1);
472 } else {
473 /* This can't be part of a note */
474 goto handle_non_note;
475 }
476
477 if (note_tree_insert(t, node, n, l, type,
478 combine_notes_concatenate))
479 die("Failed to load %s %s into notes tree "
480 "from %s",
481 type == PTR_TYPE_NOTE ? "note" : "subtree",
482 oid_to_hex(&l->key_oid), t->ref);
483
484 continue;
485
486handle_non_note:
487 /*
488 * Determine full path for this non-note entry. The
489 * filename is already found in entry.path, but the
490 * directory part of the path must be deduced from the
491 * subtree containing this entry based on our
492 * knowledge that the overall notes tree follows a
493 * strict byte-based progressive fanout structure
494 * (i.e. using 2/38, 2/2/36, etc. fanouts).
495 */
496 {
497 struct strbuf non_note_path = STRBUF_INIT;
498 const char *q = oid_to_hex(&subtree->key_oid);
499 int i;
500 for (i = 0; i < prefix_len; i++) {
501 strbuf_addch(&non_note_path, *q++);
502 strbuf_addch(&non_note_path, *q++);
503 strbuf_addch(&non_note_path, '/');
504 }
505 strbuf_addstr(&non_note_path, entry.path);
506 add_non_note(t, strbuf_detach(&non_note_path, NULL),
507 entry.mode, entry.oid->hash);
508 }
509 }
510 free(buf);
511}
512
513/*
514 * Determine optimal on-disk fanout for this part of the notes tree
515 *
516 * Given a (sub)tree and the level in the internal tree structure, determine
517 * whether or not the given existing fanout should be expanded for this
518 * (sub)tree.
519 *
520 * Values of the 'fanout' variable:
521 * - 0: No fanout (all notes are stored directly in the root notes tree)
522 * - 1: 2/38 fanout
523 * - 2: 2/2/36 fanout
524 * - 3: 2/2/2/34 fanout
525 * etc.
526 */
527static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
528 unsigned char fanout)
529{
530 /*
531 * The following is a simple heuristic that works well in practice:
532 * For each even-numbered 16-tree level (remember that each on-disk
533 * fanout level corresponds to _two_ 16-tree levels), peek at all 16
534 * entries at that tree level. If all of them are either int_nodes or
535 * subtree entries, then there are likely plenty of notes below this
536 * level, so we return an incremented fanout.
537 */
538 unsigned int i;
539 if ((n % 2) || (n > 2 * fanout))
540 return fanout;
541 for (i = 0; i < 16; i++) {
542 switch (GET_PTR_TYPE(tree->a[i])) {
543 case PTR_TYPE_SUBTREE:
544 case PTR_TYPE_INTERNAL:
545 continue;
546 default:
547 return fanout;
548 }
549 }
550 return fanout + 1;
551}
552
553/* hex SHA1 + 19 * '/' + NUL */
554#define FANOUT_PATH_MAX GIT_SHA1_HEXSZ + FANOUT_PATH_SEPARATORS + 1
555
556static void construct_path_with_fanout(const unsigned char *sha1,
557 unsigned char fanout, char *path)
558{
559 unsigned int i = 0, j = 0;
560 const char *hex_sha1 = sha1_to_hex(sha1);
561 assert(fanout < GIT_SHA1_RAWSZ);
562 while (fanout) {
563 path[i++] = hex_sha1[j++];
564 path[i++] = hex_sha1[j++];
565 path[i++] = '/';
566 fanout--;
567 }
568 xsnprintf(path + i, FANOUT_PATH_MAX - i, "%s", hex_sha1 + j);
569}
570
571static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
572 unsigned char n, unsigned char fanout, int flags,
573 each_note_fn fn, void *cb_data)
574{
575 unsigned int i;
576 void *p;
577 int ret = 0;
578 struct leaf_node *l;
579 static char path[FANOUT_PATH_MAX];
580
581 fanout = determine_fanout(tree, n, fanout);
582 for (i = 0; i < 16; i++) {
583redo:
584 p = tree->a[i];
585 switch (GET_PTR_TYPE(p)) {
586 case PTR_TYPE_INTERNAL:
587 /* recurse into int_node */
588 ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
589 fanout, flags, fn, cb_data);
590 break;
591 case PTR_TYPE_SUBTREE:
592 l = (struct leaf_node *) CLR_PTR_TYPE(p);
593 /*
594 * Subtree entries in the note tree represent parts of
595 * the note tree that have not yet been explored. There
596 * is a direct relationship between subtree entries at
597 * level 'n' in the tree, and the 'fanout' variable:
598 * Subtree entries at level 'n <= 2 * fanout' should be
599 * preserved, since they correspond exactly to a fanout
600 * directory in the on-disk structure. However, subtree
601 * entries at level 'n > 2 * fanout' should NOT be
602 * preserved, but rather consolidated into the above
603 * notes tree level. We achieve this by unconditionally
604 * unpacking subtree entries that exist below the
605 * threshold level at 'n = 2 * fanout'.
606 */
607 if (n <= 2 * fanout &&
608 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
609 /* invoke callback with subtree */
610 unsigned int path_len =
611 l->key_oid.hash[KEY_INDEX] * 2 + fanout;
612 assert(path_len < FANOUT_PATH_MAX - 1);
613 construct_path_with_fanout(l->key_oid.hash,
614 fanout,
615 path);
616 /* Create trailing slash, if needed */
617 if (path[path_len - 1] != '/')
618 path[path_len++] = '/';
619 path[path_len] = '\0';
620 ret = fn(&l->key_oid, &l->val_oid,
621 path,
622 cb_data);
623 }
624 if (n > fanout * 2 ||
625 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
626 /* unpack subtree and resume traversal */
627 tree->a[i] = NULL;
628 load_subtree(t, l, tree, n);
629 free(l);
630 goto redo;
631 }
632 break;
633 case PTR_TYPE_NOTE:
634 l = (struct leaf_node *) CLR_PTR_TYPE(p);
635 construct_path_with_fanout(l->key_oid.hash, fanout,
636 path);
637 ret = fn(&l->key_oid, &l->val_oid, path,
638 cb_data);
639 break;
640 }
641 if (ret)
642 return ret;
643 }
644 return 0;
645}
646
647struct tree_write_stack {
648 struct tree_write_stack *next;
649 struct strbuf buf;
650 char path[2]; /* path to subtree in next, if any */
651};
652
653static inline int matches_tree_write_stack(struct tree_write_stack *tws,
654 const char *full_path)
655{
656 return full_path[0] == tws->path[0] &&
657 full_path[1] == tws->path[1] &&
658 full_path[2] == '/';
659}
660
661static void write_tree_entry(struct strbuf *buf, unsigned int mode,
662 const char *path, unsigned int path_len, const
663 unsigned char *sha1)
664{
665 strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
666 strbuf_add(buf, sha1, GIT_SHA1_RAWSZ);
667}
668
669static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
670 const char *path)
671{
672 struct tree_write_stack *n;
673 assert(!tws->next);
674 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
675 n = (struct tree_write_stack *)
676 xmalloc(sizeof(struct tree_write_stack));
677 n->next = NULL;
678 strbuf_init(&n->buf, 256 * (32 + GIT_SHA1_HEXSZ)); /* assume 256 entries per tree */
679 n->path[0] = n->path[1] = '\0';
680 tws->next = n;
681 tws->path[0] = path[0];
682 tws->path[1] = path[1];
683}
684
685static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
686{
687 int ret;
688 struct tree_write_stack *n = tws->next;
689 struct object_id s;
690 if (n) {
691 ret = tree_write_stack_finish_subtree(n);
692 if (ret)
693 return ret;
694 ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s.hash);
695 if (ret)
696 return ret;
697 strbuf_release(&n->buf);
698 free(n);
699 tws->next = NULL;
700 write_tree_entry(&tws->buf, 040000, tws->path, 2, s.hash);
701 tws->path[0] = tws->path[1] = '\0';
702 }
703 return 0;
704}
705
706static int write_each_note_helper(struct tree_write_stack *tws,
707 const char *path, unsigned int mode,
708 const struct object_id *oid)
709{
710 size_t path_len = strlen(path);
711 unsigned int n = 0;
712 int ret;
713
714 /* Determine common part of tree write stack */
715 while (tws && 3 * n < path_len &&
716 matches_tree_write_stack(tws, path + 3 * n)) {
717 n++;
718 tws = tws->next;
719 }
720
721 /* tws point to last matching tree_write_stack entry */
722 ret = tree_write_stack_finish_subtree(tws);
723 if (ret)
724 return ret;
725
726 /* Start subtrees needed to satisfy path */
727 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
728 tree_write_stack_init_subtree(tws, path + 3 * n);
729 n++;
730 tws = tws->next;
731 }
732
733 /* There should be no more directory components in the given path */
734 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
735
736 /* Finally add given entry to the current tree object */
737 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
738 oid->hash);
739
740 return 0;
741}
742
743struct write_each_note_data {
744 struct tree_write_stack *root;
745 struct non_note *next_non_note;
746};
747
748static int write_each_non_note_until(const char *note_path,
749 struct write_each_note_data *d)
750{
751 struct non_note *n = d->next_non_note;
752 int cmp = 0, ret;
753 while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
754 if (note_path && cmp == 0)
755 ; /* do nothing, prefer note to non-note */
756 else {
757 ret = write_each_note_helper(d->root, n->path, n->mode,
758 &n->oid);
759 if (ret)
760 return ret;
761 }
762 n = n->next;
763 }
764 d->next_non_note = n;
765 return 0;
766}
767
768static int write_each_note(const struct object_id *object_oid,
769 const struct object_id *note_oid, char *note_path,
770 void *cb_data)
771{
772 struct write_each_note_data *d =
773 (struct write_each_note_data *) cb_data;
774 size_t note_path_len = strlen(note_path);
775 unsigned int mode = 0100644;
776
777 if (note_path[note_path_len - 1] == '/') {
778 /* subtree entry */
779 note_path_len--;
780 note_path[note_path_len] = '\0';
781 mode = 040000;
782 }
783 assert(note_path_len <= GIT_SHA1_HEXSZ + FANOUT_PATH_SEPARATORS);
784
785 /* Weave non-note entries into note entries */
786 return write_each_non_note_until(note_path, d) ||
787 write_each_note_helper(d->root, note_path, mode, note_oid);
788}
789
790struct note_delete_list {
791 struct note_delete_list *next;
792 const unsigned char *sha1;
793};
794
795static int prune_notes_helper(const struct object_id *object_oid,
796 const struct object_id *note_oid, char *note_path,
797 void *cb_data)
798{
799 struct note_delete_list **l = (struct note_delete_list **) cb_data;
800 struct note_delete_list *n;
801
802 if (has_object_file(object_oid))
803 return 0; /* nothing to do for this note */
804
805 /* failed to find object => prune this note */
806 n = (struct note_delete_list *) xmalloc(sizeof(*n));
807 n->next = *l;
808 n->sha1 = object_oid->hash;
809 *l = n;
810 return 0;
811}
812
813int combine_notes_concatenate(unsigned char *cur_sha1,
814 const unsigned char *new_sha1)
815{
816 char *cur_msg = NULL, *new_msg = NULL, *buf;
817 unsigned long cur_len, new_len, buf_len;
818 enum object_type cur_type, new_type;
819 int ret;
820
821 /* read in both note blob objects */
822 if (!is_null_sha1(new_sha1))
823 new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
824 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
825 free(new_msg);
826 return 0;
827 }
828 if (!is_null_sha1(cur_sha1))
829 cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
830 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
831 free(cur_msg);
832 free(new_msg);
833 hashcpy(cur_sha1, new_sha1);
834 return 0;
835 }
836
837 /* we will separate the notes by two newlines anyway */
838 if (cur_msg[cur_len - 1] == '\n')
839 cur_len--;
840
841 /* concatenate cur_msg and new_msg into buf */
842 buf_len = cur_len + 2 + new_len;
843 buf = (char *) xmalloc(buf_len);
844 memcpy(buf, cur_msg, cur_len);
845 buf[cur_len] = '\n';
846 buf[cur_len + 1] = '\n';
847 memcpy(buf + cur_len + 2, new_msg, new_len);
848 free(cur_msg);
849 free(new_msg);
850
851 /* create a new blob object from buf */
852 ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
853 free(buf);
854 return ret;
855}
856
857int combine_notes_overwrite(unsigned char *cur_sha1,
858 const unsigned char *new_sha1)
859{
860 hashcpy(cur_sha1, new_sha1);
861 return 0;
862}
863
864int combine_notes_ignore(unsigned char *cur_sha1,
865 const unsigned char *new_sha1)
866{
867 return 0;
868}
869
870/*
871 * Add the lines from the named object to list, with trailing
872 * newlines removed.
873 */
874static int string_list_add_note_lines(struct string_list *list,
875 const unsigned char *sha1)
876{
877 char *data;
878 unsigned long len;
879 enum object_type t;
880
881 if (is_null_sha1(sha1))
882 return 0;
883
884 /* read_sha1_file NUL-terminates */
885 data = read_sha1_file(sha1, &t, &len);
886 if (t != OBJ_BLOB || !data || !len) {
887 free(data);
888 return t != OBJ_BLOB || !data;
889 }
890
891 /*
892 * If the last line of the file is EOL-terminated, this will
893 * add an empty string to the list. But it will be removed
894 * later, along with any empty strings that came from empty
895 * lines within the file.
896 */
897 string_list_split(list, data, '\n', -1);
898 free(data);
899 return 0;
900}
901
902static int string_list_join_lines_helper(struct string_list_item *item,
903 void *cb_data)
904{
905 struct strbuf *buf = cb_data;
906 strbuf_addstr(buf, item->string);
907 strbuf_addch(buf, '\n');
908 return 0;
909}
910
911int combine_notes_cat_sort_uniq(unsigned char *cur_sha1,
912 const unsigned char *new_sha1)
913{
914 struct string_list sort_uniq_list = STRING_LIST_INIT_DUP;
915 struct strbuf buf = STRBUF_INIT;
916 int ret = 1;
917
918 /* read both note blob objects into unique_lines */
919 if (string_list_add_note_lines(&sort_uniq_list, cur_sha1))
920 goto out;
921 if (string_list_add_note_lines(&sort_uniq_list, new_sha1))
922 goto out;
923 string_list_remove_empty_items(&sort_uniq_list, 0);
924 string_list_sort(&sort_uniq_list);
925 string_list_remove_duplicates(&sort_uniq_list, 0);
926
927 /* create a new blob object from sort_uniq_list */
928 if (for_each_string_list(&sort_uniq_list,
929 string_list_join_lines_helper, &buf))
930 goto out;
931
932 ret = write_sha1_file(buf.buf, buf.len, blob_type, cur_sha1);
933
934out:
935 strbuf_release(&buf);
936 string_list_clear(&sort_uniq_list, 0);
937 return ret;
938}
939
940static int string_list_add_one_ref(const char *refname, const struct object_id *oid,
941 int flag, void *cb)
942{
943 struct string_list *refs = cb;
944 if (!unsorted_string_list_has_string(refs, refname))
945 string_list_append(refs, refname);
946 return 0;
947}
948
949/*
950 * The list argument must have strdup_strings set on it.
951 */
952void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
953{
954 assert(list->strdup_strings);
955 if (has_glob_specials(glob)) {
956 for_each_glob_ref(string_list_add_one_ref, glob, list);
957 } else {
958 struct object_id oid;
959 if (get_oid(glob, &oid))
960 warning("notes ref %s is invalid", glob);
961 if (!unsorted_string_list_has_string(list, glob))
962 string_list_append(list, glob);
963 }
964}
965
966void string_list_add_refs_from_colon_sep(struct string_list *list,
967 const char *globs)
968{
969 struct string_list split = STRING_LIST_INIT_NODUP;
970 char *globs_copy = xstrdup(globs);
971 int i;
972
973 string_list_split_in_place(&split, globs_copy, ':', -1);
974 string_list_remove_empty_items(&split, 0);
975
976 for (i = 0; i < split.nr; i++)
977 string_list_add_refs_by_glob(list, split.items[i].string);
978
979 string_list_clear(&split, 0);
980 free(globs_copy);
981}
982
983static int notes_display_config(const char *k, const char *v, void *cb)
984{
985 int *load_refs = cb;
986
987 if (*load_refs && !strcmp(k, "notes.displayref")) {
988 if (!v)
989 config_error_nonbool(k);
990 string_list_add_refs_by_glob(&display_notes_refs, v);
991 }
992
993 return 0;
994}
995
996const char *default_notes_ref(void)
997{
998 const char *notes_ref = NULL;
999 if (!notes_ref)
1000 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
1001 if (!notes_ref)
1002 notes_ref = notes_ref_name; /* value of core.notesRef config */
1003 if (!notes_ref)
1004 notes_ref = GIT_NOTES_DEFAULT_REF;
1005 return notes_ref;
1006}
1007
1008void init_notes(struct notes_tree *t, const char *notes_ref,
1009 combine_notes_fn combine_notes, int flags)
1010{
1011 struct object_id oid, object_oid;
1012 unsigned mode;
1013 struct leaf_node root_tree;
1014
1015 if (!t)
1016 t = &default_notes_tree;
1017 assert(!t->initialized);
1018
1019 if (!notes_ref)
1020 notes_ref = default_notes_ref();
1021
1022 if (!combine_notes)
1023 combine_notes = combine_notes_concatenate;
1024
1025 t->root = (struct int_node *) xcalloc(1, sizeof(struct int_node));
1026 t->first_non_note = NULL;
1027 t->prev_non_note = NULL;
1028 t->ref = xstrdup_or_null(notes_ref);
1029 t->update_ref = (flags & NOTES_INIT_WRITABLE) ? t->ref : NULL;
1030 t->combine_notes = combine_notes;
1031 t->initialized = 1;
1032 t->dirty = 0;
1033
1034 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
1035 get_sha1_treeish(notes_ref, object_oid.hash))
1036 return;
1037 if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, object_oid.hash))
1038 die("Cannot use notes ref %s", notes_ref);
1039 if (get_tree_entry(object_oid.hash, "", oid.hash, &mode))
1040 die("Failed to read notes tree referenced by %s (%s)",
1041 notes_ref, oid_to_hex(&object_oid));
1042
1043 oidclr(&root_tree.key_oid);
1044 oidcpy(&root_tree.val_oid, &oid);
1045 load_subtree(t, &root_tree, t->root, 0);
1046}
1047
1048struct notes_tree **load_notes_trees(struct string_list *refs, int flags)
1049{
1050 struct string_list_item *item;
1051 int counter = 0;
1052 struct notes_tree **trees;
1053 ALLOC_ARRAY(trees, refs->nr + 1);
1054 for_each_string_list_item(item, refs) {
1055 struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
1056 init_notes(t, item->string, combine_notes_ignore, flags);
1057 trees[counter++] = t;
1058 }
1059 trees[counter] = NULL;
1060 return trees;
1061}
1062
1063void init_display_notes(struct display_notes_opt *opt)
1064{
1065 char *display_ref_env;
1066 int load_config_refs = 0;
1067 display_notes_refs.strdup_strings = 1;
1068
1069 assert(!display_notes_trees);
1070
1071 if (!opt || opt->use_default_notes > 0 ||
1072 (opt->use_default_notes == -1 && !opt->extra_notes_refs.nr)) {
1073 string_list_append(&display_notes_refs, default_notes_ref());
1074 display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
1075 if (display_ref_env) {
1076 string_list_add_refs_from_colon_sep(&display_notes_refs,
1077 display_ref_env);
1078 load_config_refs = 0;
1079 } else
1080 load_config_refs = 1;
1081 }
1082
1083 git_config(notes_display_config, &load_config_refs);
1084
1085 if (opt) {
1086 struct string_list_item *item;
1087 for_each_string_list_item(item, &opt->extra_notes_refs)
1088 string_list_add_refs_by_glob(&display_notes_refs,
1089 item->string);
1090 }
1091
1092 display_notes_trees = load_notes_trees(&display_notes_refs, 0);
1093 string_list_clear(&display_notes_refs, 0);
1094}
1095
1096int add_note(struct notes_tree *t, const struct object_id *object_oid,
1097 const struct object_id *note_oid, combine_notes_fn combine_notes)
1098{
1099 struct leaf_node *l;
1100
1101 if (!t)
1102 t = &default_notes_tree;
1103 assert(t->initialized);
1104 t->dirty = 1;
1105 if (!combine_notes)
1106 combine_notes = t->combine_notes;
1107 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
1108 oidcpy(&l->key_oid, object_oid);
1109 oidcpy(&l->val_oid, note_oid);
1110 return note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
1111}
1112
1113int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1114{
1115 struct leaf_node l;
1116
1117 if (!t)
1118 t = &default_notes_tree;
1119 assert(t->initialized);
1120 hashcpy(l.key_oid.hash, object_sha1);
1121 oidclr(&l.val_oid);
1122 note_tree_remove(t, t->root, 0, &l);
1123 if (is_null_oid(&l.val_oid)) /* no note was removed */
1124 return 1;
1125 t->dirty = 1;
1126 return 0;
1127}
1128
1129const struct object_id *get_note(struct notes_tree *t,
1130 const struct object_id *oid)
1131{
1132 struct leaf_node *found;
1133
1134 if (!t)
1135 t = &default_notes_tree;
1136 assert(t->initialized);
1137 found = note_tree_find(t, t->root, 0, oid->hash);
1138 return found ? &found->val_oid : NULL;
1139}
1140
1141int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
1142 void *cb_data)
1143{
1144 if (!t)
1145 t = &default_notes_tree;
1146 assert(t->initialized);
1147 return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
1148}
1149
1150int write_notes_tree(struct notes_tree *t, unsigned char *result)
1151{
1152 struct tree_write_stack root;
1153 struct write_each_note_data cb_data;
1154 int ret;
1155
1156 if (!t)
1157 t = &default_notes_tree;
1158 assert(t->initialized);
1159
1160 /* Prepare for traversal of current notes tree */
1161 root.next = NULL; /* last forward entry in list is grounded */
1162 strbuf_init(&root.buf, 256 * (32 + GIT_SHA1_HEXSZ)); /* assume 256 entries */
1163 root.path[0] = root.path[1] = '\0';
1164 cb_data.root = &root;
1165 cb_data.next_non_note = t->first_non_note;
1166
1167 /* Write tree objects representing current notes tree */
1168 ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
1169 FOR_EACH_NOTE_YIELD_SUBTREES,
1170 write_each_note, &cb_data) ||
1171 write_each_non_note_until(NULL, &cb_data) ||
1172 tree_write_stack_finish_subtree(&root) ||
1173 write_sha1_file(root.buf.buf, root.buf.len, tree_type, result);
1174 strbuf_release(&root.buf);
1175 return ret;
1176}
1177
1178void prune_notes(struct notes_tree *t, int flags)
1179{
1180 struct note_delete_list *l = NULL;
1181
1182 if (!t)
1183 t = &default_notes_tree;
1184 assert(t->initialized);
1185
1186 for_each_note(t, 0, prune_notes_helper, &l);
1187
1188 while (l) {
1189 if (flags & NOTES_PRUNE_VERBOSE)
1190 printf("%s\n", sha1_to_hex(l->sha1));
1191 if (!(flags & NOTES_PRUNE_DRYRUN))
1192 remove_note(t, l->sha1);
1193 l = l->next;
1194 }
1195}
1196
1197void free_notes(struct notes_tree *t)
1198{
1199 if (!t)
1200 t = &default_notes_tree;
1201 if (t->root)
1202 note_tree_free(t->root);
1203 free(t->root);
1204 while (t->first_non_note) {
1205 t->prev_non_note = t->first_non_note->next;
1206 free(t->first_non_note->path);
1207 free(t->first_non_note);
1208 t->first_non_note = t->prev_non_note;
1209 }
1210 free(t->ref);
1211 memset(t, 0, sizeof(struct notes_tree));
1212}
1213
1214/*
1215 * Fill the given strbuf with the notes associated with the given object.
1216 *
1217 * If the given notes_tree structure is not initialized, it will be auto-
1218 * initialized to the default value (see documentation for init_notes() above).
1219 * If the given notes_tree is NULL, the internal/default notes_tree will be
1220 * used instead.
1221 *
1222 * (raw != 0) gives the %N userformat; otherwise, the note message is given
1223 * for human consumption.
1224 */
1225static void format_note(struct notes_tree *t, const struct object_id *object_oid,
1226 struct strbuf *sb, const char *output_encoding, int raw)
1227{
1228 static const char utf8[] = "utf-8";
1229 const struct object_id *oid;
1230 char *msg, *msg_p;
1231 unsigned long linelen, msglen;
1232 enum object_type type;
1233
1234 if (!t)
1235 t = &default_notes_tree;
1236 if (!t->initialized)
1237 init_notes(t, NULL, NULL, 0);
1238
1239 oid = get_note(t, object_oid);
1240 if (!oid)
1241 return;
1242
1243 if (!(msg = read_sha1_file(oid->hash, &type, &msglen)) || type != OBJ_BLOB) {
1244 free(msg);
1245 return;
1246 }
1247
1248 if (output_encoding && *output_encoding &&
1249 !is_encoding_utf8(output_encoding)) {
1250 char *reencoded = reencode_string(msg, output_encoding, utf8);
1251 if (reencoded) {
1252 free(msg);
1253 msg = reencoded;
1254 msglen = strlen(msg);
1255 }
1256 }
1257
1258 /* we will end the annotation by a newline anyway */
1259 if (msglen && msg[msglen - 1] == '\n')
1260 msglen--;
1261
1262 if (!raw) {
1263 const char *ref = t->ref;
1264 if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
1265 strbuf_addstr(sb, "\nNotes:\n");
1266 } else {
1267 if (starts_with(ref, "refs/"))
1268 ref += 5;
1269 if (starts_with(ref, "notes/"))
1270 ref += 6;
1271 strbuf_addf(sb, "\nNotes (%s):\n", ref);
1272 }
1273 }
1274
1275 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
1276 linelen = strchrnul(msg_p, '\n') - msg_p;
1277
1278 if (!raw)
1279 strbuf_addstr(sb, " ");
1280 strbuf_add(sb, msg_p, linelen);
1281 strbuf_addch(sb, '\n');
1282 }
1283
1284 free(msg);
1285}
1286
1287void format_display_notes(const struct object_id *object_oid,
1288 struct strbuf *sb, const char *output_encoding, int raw)
1289{
1290 int i;
1291 assert(display_notes_trees);
1292 for (i = 0; display_notes_trees[i]; i++)
1293 format_note(display_notes_trees[i], object_oid, sb,
1294 output_encoding, raw);
1295}
1296
1297int copy_note(struct notes_tree *t,
1298 const struct object_id *from_obj, const struct object_id *to_obj,
1299 int force, combine_notes_fn combine_notes)
1300{
1301 const struct object_id *note = get_note(t, from_obj);
1302 const struct object_id *existing_note = get_note(t, to_obj);
1303
1304 if (!force && existing_note)
1305 return 1;
1306
1307 if (note)
1308 return add_note(t, to_obj, note, combine_notes);
1309 else if (existing_note)
1310 return add_note(t, to_obj, &null_oid, combine_notes);
1311
1312 return 0;
1313}
1314
1315void expand_notes_ref(struct strbuf *sb)
1316{
1317 if (starts_with(sb->buf, "refs/notes/"))
1318 return; /* we're happy */
1319 else if (starts_with(sb->buf, "notes/"))
1320 strbuf_insert(sb, 0, "refs/", 5);
1321 else
1322 strbuf_insert(sb, 0, "refs/notes/", 11);
1323}
1324
1325void expand_loose_notes_ref(struct strbuf *sb)
1326{
1327 struct object_id object;
1328
1329 if (get_oid(sb->buf, &object)) {
1330 /* fallback to expand_notes_ref */
1331 expand_notes_ref(sb);
1332 }
1333}