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a97a7468 | 1 | #include "cache.h" |
a97a7468 | 2 | #include "notes.h" |
73f464b5 | 3 | #include "blob.h" |
61a7cca0 | 4 | #include "tree.h" |
a97a7468 JS |
5 | #include "utf8.h" |
6 | #include "strbuf.h" | |
fd53c9eb JS |
7 | #include "tree-walk.h" |
8 | ||
23123aec JH |
9 | /* |
10 | * Use a non-balancing simple 16-tree structure with struct int_node as | |
11 | * internal nodes, and struct leaf_node as leaf nodes. Each int_node has a | |
12 | * 16-array of pointers to its children. | |
13 | * The bottom 2 bits of each pointer is used to identify the pointer type | |
14 | * - ptr & 3 == 0 - NULL pointer, assert(ptr == NULL) | |
15 | * - ptr & 3 == 1 - pointer to next internal node - cast to struct int_node * | |
16 | * - ptr & 3 == 2 - pointer to note entry - cast to struct leaf_node * | |
17 | * - ptr & 3 == 3 - pointer to subtree entry - cast to struct leaf_node * | |
18 | * | |
19 | * The root node is a statically allocated struct int_node. | |
20 | */ | |
21 | struct int_node { | |
22 | void *a[16]; | |
fd53c9eb JS |
23 | }; |
24 | ||
23123aec JH |
25 | /* |
26 | * Leaf nodes come in two variants, note entries and subtree entries, | |
27 | * distinguished by the LSb of the leaf node pointer (see above). | |
a7e7eff6 | 28 | * As a note entry, the key is the SHA1 of the referenced object, and the |
23123aec JH |
29 | * value is the SHA1 of the note object. |
30 | * As a subtree entry, the key is the prefix SHA1 (w/trailing NULs) of the | |
a7e7eff6 | 31 | * referenced object, using the last byte of the key to store the length of |
23123aec JH |
32 | * the prefix. The value is the SHA1 of the tree object containing the notes |
33 | * subtree. | |
34 | */ | |
35 | struct leaf_node { | |
36 | unsigned char key_sha1[20]; | |
37 | unsigned char val_sha1[20]; | |
fd53c9eb | 38 | }; |
a97a7468 | 39 | |
851c2b37 JH |
40 | /* |
41 | * A notes tree may contain entries that are not notes, and that do not follow | |
42 | * the naming conventions of notes. There are typically none/few of these, but | |
43 | * we still need to keep track of them. Keep a simple linked list sorted alpha- | |
44 | * betically on the non-note path. The list is populated when parsing tree | |
45 | * objects in load_subtree(), and the non-notes are correctly written back into | |
46 | * the tree objects produced by write_notes_tree(). | |
47 | */ | |
48 | struct non_note { | |
49 | struct non_note *next; /* grounded (last->next == NULL) */ | |
50 | char *path; | |
51 | unsigned int mode; | |
52 | unsigned char sha1[20]; | |
53 | }; | |
54 | ||
23123aec JH |
55 | #define PTR_TYPE_NULL 0 |
56 | #define PTR_TYPE_INTERNAL 1 | |
57 | #define PTR_TYPE_NOTE 2 | |
58 | #define PTR_TYPE_SUBTREE 3 | |
fd53c9eb | 59 | |
23123aec JH |
60 | #define GET_PTR_TYPE(ptr) ((uintptr_t) (ptr) & 3) |
61 | #define CLR_PTR_TYPE(ptr) ((void *) ((uintptr_t) (ptr) & ~3)) | |
62 | #define SET_PTR_TYPE(ptr, type) ((void *) ((uintptr_t) (ptr) | (type))) | |
fd53c9eb | 63 | |
1ec666b0 | 64 | #define GET_NIBBLE(n, sha1) (((sha1[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f) |
fd53c9eb | 65 | |
23123aec JH |
66 | #define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \ |
67 | (memcmp(key_sha1, subtree_sha1, subtree_sha1[19])) | |
fd53c9eb | 68 | |
cd305392 | 69 | struct notes_tree default_notes_tree; |
23123aec | 70 | |
851c2b37 JH |
71 | static void load_subtree(struct notes_tree *t, struct leaf_node *subtree, |
72 | struct int_node *node, unsigned int n); | |
23123aec JH |
73 | |
74 | /* | |
ef8db638 | 75 | * Search the tree until the appropriate location for the given key is found: |
23123aec | 76 | * 1. Start at the root node, with n = 0 |
ef8db638 JH |
77 | * 2. If a[0] at the current level is a matching subtree entry, unpack that |
78 | * subtree entry and remove it; restart search at the current level. | |
79 | * 3. Use the nth nibble of the key as an index into a: | |
80 | * - If a[n] is an int_node, recurse from #2 into that node and increment n | |
23123aec JH |
81 | * - If a matching subtree entry, unpack that subtree entry (and remove it); |
82 | * restart search at the current level. | |
ef8db638 JH |
83 | * - Otherwise, we have found one of the following: |
84 | * - a subtree entry which does not match the key | |
85 | * - a note entry which may or may not match the key | |
86 | * - an unused leaf node (NULL) | |
87 | * In any case, set *tree and *n, and return pointer to the tree location. | |
23123aec | 88 | */ |
851c2b37 | 89 | static void **note_tree_search(struct notes_tree *t, struct int_node **tree, |
ef8db638 | 90 | unsigned char *n, const unsigned char *key_sha1) |
23123aec JH |
91 | { |
92 | struct leaf_node *l; | |
ef8db638 JH |
93 | unsigned char i; |
94 | void *p = (*tree)->a[0]; | |
23123aec | 95 | |
ef8db638 JH |
96 | if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) { |
97 | l = (struct leaf_node *) CLR_PTR_TYPE(p); | |
98 | if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) { | |
99 | /* unpack tree and resume search */ | |
100 | (*tree)->a[0] = NULL; | |
851c2b37 | 101 | load_subtree(t, l, *tree, *n); |
ef8db638 | 102 | free(l); |
851c2b37 | 103 | return note_tree_search(t, tree, n, key_sha1); |
ef8db638 JH |
104 | } |
105 | } | |
106 | ||
107 | i = GET_NIBBLE(*n, key_sha1); | |
108 | p = (*tree)->a[i]; | |
0ab1faae | 109 | switch (GET_PTR_TYPE(p)) { |
23123aec | 110 | case PTR_TYPE_INTERNAL: |
ef8db638 JH |
111 | *tree = CLR_PTR_TYPE(p); |
112 | (*n)++; | |
851c2b37 | 113 | return note_tree_search(t, tree, n, key_sha1); |
23123aec JH |
114 | case PTR_TYPE_SUBTREE: |
115 | l = (struct leaf_node *) CLR_PTR_TYPE(p); | |
116 | if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) { | |
117 | /* unpack tree and resume search */ | |
ef8db638 | 118 | (*tree)->a[i] = NULL; |
851c2b37 | 119 | load_subtree(t, l, *tree, *n); |
23123aec | 120 | free(l); |
851c2b37 | 121 | return note_tree_search(t, tree, n, key_sha1); |
23123aec | 122 | } |
ef8db638 | 123 | /* fall through */ |
23123aec | 124 | default: |
ef8db638 | 125 | return &((*tree)->a[i]); |
fd53c9eb | 126 | } |
ef8db638 | 127 | } |
23123aec | 128 | |
ef8db638 JH |
129 | /* |
130 | * To find a leaf_node: | |
131 | * Search to the tree location appropriate for the given key: | |
132 | * If a note entry with matching key, return the note entry, else return NULL. | |
133 | */ | |
851c2b37 JH |
134 | static struct leaf_node *note_tree_find(struct notes_tree *t, |
135 | struct int_node *tree, unsigned char n, | |
ef8db638 JH |
136 | const unsigned char *key_sha1) |
137 | { | |
851c2b37 | 138 | void **p = note_tree_search(t, &tree, &n, key_sha1); |
ef8db638 JH |
139 | if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) { |
140 | struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p); | |
141 | if (!hashcmp(key_sha1, l->key_sha1)) | |
142 | return l; | |
23123aec JH |
143 | } |
144 | return NULL; | |
fd53c9eb JS |
145 | } |
146 | ||
23123aec JH |
147 | /* |
148 | * To insert a leaf_node: | |
ef8db638 JH |
149 | * Search to the tree location appropriate for the given leaf_node's key: |
150 | * - If location is unused (NULL), store the tweaked pointer directly there | |
151 | * - If location holds a note entry that matches the note-to-be-inserted, then | |
73f464b5 | 152 | * combine the two notes (by calling the given combine_notes function). |
ef8db638 JH |
153 | * - If location holds a note entry that matches the subtree-to-be-inserted, |
154 | * then unpack the subtree-to-be-inserted into the location. | |
155 | * - If location holds a matching subtree entry, unpack the subtree at that | |
156 | * location, and restart the insert operation from that level. | |
157 | * - Else, create a new int_node, holding both the node-at-location and the | |
158 | * node-to-be-inserted, and store the new int_node into the location. | |
23123aec | 159 | */ |
851c2b37 JH |
160 | static void note_tree_insert(struct notes_tree *t, struct int_node *tree, |
161 | unsigned char n, struct leaf_node *entry, unsigned char type, | |
73f464b5 | 162 | combine_notes_fn combine_notes) |
fd53c9eb | 163 | { |
23123aec | 164 | struct int_node *new_node; |
ef8db638 | 165 | struct leaf_node *l; |
851c2b37 | 166 | void **p = note_tree_search(t, &tree, &n, entry->key_sha1); |
ef8db638 JH |
167 | |
168 | assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */ | |
169 | l = (struct leaf_node *) CLR_PTR_TYPE(*p); | |
0ab1faae | 170 | switch (GET_PTR_TYPE(*p)) { |
23123aec | 171 | case PTR_TYPE_NULL: |
ef8db638 JH |
172 | assert(!*p); |
173 | *p = SET_PTR_TYPE(entry, type); | |
174 | return; | |
175 | case PTR_TYPE_NOTE: | |
176 | switch (type) { | |
177 | case PTR_TYPE_NOTE: | |
178 | if (!hashcmp(l->key_sha1, entry->key_sha1)) { | |
179 | /* skip concatenation if l == entry */ | |
180 | if (!hashcmp(l->val_sha1, entry->val_sha1)) | |
181 | return; | |
182 | ||
73f464b5 JH |
183 | if (combine_notes(l->val_sha1, entry->val_sha1)) |
184 | die("failed to combine notes %s and %s" | |
185 | " for object %s", | |
ef8db638 | 186 | sha1_to_hex(l->val_sha1), |
73f464b5 | 187 | sha1_to_hex(entry->val_sha1), |
ef8db638 JH |
188 | sha1_to_hex(l->key_sha1)); |
189 | free(entry); | |
190 | return; | |
191 | } | |
192 | break; | |
193 | case PTR_TYPE_SUBTREE: | |
194 | if (!SUBTREE_SHA1_PREFIXCMP(l->key_sha1, | |
195 | entry->key_sha1)) { | |
196 | /* unpack 'entry' */ | |
851c2b37 | 197 | load_subtree(t, entry, tree, n); |
ef8db638 JH |
198 | free(entry); |
199 | return; | |
200 | } | |
201 | break; | |
202 | } | |
203 | break; | |
204 | case PTR_TYPE_SUBTREE: | |
205 | if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) { | |
206 | /* unpack 'l' and restart insert */ | |
207 | *p = NULL; | |
851c2b37 | 208 | load_subtree(t, l, tree, n); |
ef8db638 | 209 | free(l); |
851c2b37 JH |
210 | note_tree_insert(t, tree, n, entry, type, |
211 | combine_notes); | |
ef8db638 | 212 | return; |
23123aec | 213 | } |
ef8db638 | 214 | break; |
fd53c9eb | 215 | } |
ef8db638 JH |
216 | |
217 | /* non-matching leaf_node */ | |
218 | assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE || | |
219 | GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE); | |
220 | new_node = (struct int_node *) xcalloc(sizeof(struct int_node), 1); | |
851c2b37 JH |
221 | note_tree_insert(t, new_node, n + 1, l, GET_PTR_TYPE(*p), |
222 | combine_notes); | |
ef8db638 | 223 | *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL); |
851c2b37 | 224 | note_tree_insert(t, new_node, n + 1, entry, type, combine_notes); |
23123aec | 225 | } |
fd53c9eb | 226 | |
1ec666b0 JH |
227 | /* |
228 | * How to consolidate an int_node: | |
229 | * If there are > 1 non-NULL entries, give up and return non-zero. | |
230 | * Otherwise replace the int_node at the given index in the given parent node | |
231 | * with the only entry (or a NULL entry if no entries) from the given tree, | |
232 | * and return 0. | |
233 | */ | |
234 | static int note_tree_consolidate(struct int_node *tree, | |
235 | struct int_node *parent, unsigned char index) | |
236 | { | |
237 | unsigned int i; | |
238 | void *p = NULL; | |
239 | ||
240 | assert(tree && parent); | |
241 | assert(CLR_PTR_TYPE(parent->a[index]) == tree); | |
242 | ||
243 | for (i = 0; i < 16; i++) { | |
244 | if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) { | |
245 | if (p) /* more than one entry */ | |
246 | return -2; | |
247 | p = tree->a[i]; | |
248 | } | |
249 | } | |
250 | ||
251 | /* replace tree with p in parent[index] */ | |
252 | parent->a[index] = p; | |
253 | free(tree); | |
254 | return 0; | |
255 | } | |
256 | ||
257 | /* | |
258 | * To remove a leaf_node: | |
259 | * Search to the tree location appropriate for the given leaf_node's key: | |
260 | * - If location does not hold a matching entry, abort and do nothing. | |
261 | * - Replace the matching leaf_node with a NULL entry (and free the leaf_node). | |
262 | * - Consolidate int_nodes repeatedly, while walking up the tree towards root. | |
263 | */ | |
cd305392 JH |
264 | static void note_tree_remove(struct notes_tree *t, struct int_node *tree, |
265 | unsigned char n, struct leaf_node *entry) | |
1ec666b0 JH |
266 | { |
267 | struct leaf_node *l; | |
268 | struct int_node *parent_stack[20]; | |
269 | unsigned char i, j; | |
851c2b37 | 270 | void **p = note_tree_search(t, &tree, &n, entry->key_sha1); |
1ec666b0 JH |
271 | |
272 | assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */ | |
273 | if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE) | |
274 | return; /* type mismatch, nothing to remove */ | |
275 | l = (struct leaf_node *) CLR_PTR_TYPE(*p); | |
276 | if (hashcmp(l->key_sha1, entry->key_sha1)) | |
277 | return; /* key mismatch, nothing to remove */ | |
278 | ||
279 | /* we have found a matching entry */ | |
280 | free(l); | |
281 | *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL); | |
282 | ||
283 | /* consolidate this tree level, and parent levels, if possible */ | |
284 | if (!n) | |
285 | return; /* cannot consolidate top level */ | |
286 | /* first, build stack of ancestors between root and current node */ | |
cd305392 | 287 | parent_stack[0] = t->root; |
1ec666b0 JH |
288 | for (i = 0; i < n; i++) { |
289 | j = GET_NIBBLE(i, entry->key_sha1); | |
290 | parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]); | |
291 | } | |
292 | assert(i == n && parent_stack[i] == tree); | |
293 | /* next, unwind stack until note_tree_consolidate() is done */ | |
294 | while (i > 0 && | |
295 | !note_tree_consolidate(parent_stack[i], parent_stack[i - 1], | |
296 | GET_NIBBLE(i - 1, entry->key_sha1))) | |
297 | i--; | |
298 | } | |
299 | ||
23123aec JH |
300 | /* Free the entire notes data contained in the given tree */ |
301 | static void note_tree_free(struct int_node *tree) | |
302 | { | |
303 | unsigned int i; | |
304 | for (i = 0; i < 16; i++) { | |
305 | void *p = tree->a[i]; | |
0ab1faae | 306 | switch (GET_PTR_TYPE(p)) { |
23123aec JH |
307 | case PTR_TYPE_INTERNAL: |
308 | note_tree_free(CLR_PTR_TYPE(p)); | |
309 | /* fall through */ | |
310 | case PTR_TYPE_NOTE: | |
311 | case PTR_TYPE_SUBTREE: | |
312 | free(CLR_PTR_TYPE(p)); | |
313 | } | |
fd53c9eb | 314 | } |
23123aec | 315 | } |
fd53c9eb | 316 | |
23123aec JH |
317 | /* |
318 | * Convert a partial SHA1 hex string to the corresponding partial SHA1 value. | |
319 | * - hex - Partial SHA1 segment in ASCII hex format | |
320 | * - hex_len - Length of above segment. Must be multiple of 2 between 0 and 40 | |
321 | * - sha1 - Partial SHA1 value is written here | |
322 | * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20 | |
0ab1faae | 323 | * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format)). |
23123aec JH |
324 | * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2). |
325 | * Pads sha1 with NULs up to sha1_len (not included in returned length). | |
326 | */ | |
327 | static int get_sha1_hex_segment(const char *hex, unsigned int hex_len, | |
328 | unsigned char *sha1, unsigned int sha1_len) | |
329 | { | |
330 | unsigned int i, len = hex_len >> 1; | |
331 | if (hex_len % 2 != 0 || len > sha1_len) | |
332 | return -1; | |
333 | for (i = 0; i < len; i++) { | |
334 | unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]); | |
335 | if (val & ~0xff) | |
336 | return -1; | |
337 | *sha1++ = val; | |
338 | hex += 2; | |
339 | } | |
340 | for (; i < sha1_len; i++) | |
341 | *sha1++ = 0; | |
342 | return len; | |
fd53c9eb JS |
343 | } |
344 | ||
851c2b37 JH |
345 | static int non_note_cmp(const struct non_note *a, const struct non_note *b) |
346 | { | |
347 | return strcmp(a->path, b->path); | |
348 | } | |
349 | ||
350 | static void add_non_note(struct notes_tree *t, const char *path, | |
351 | unsigned int mode, const unsigned char *sha1) | |
352 | { | |
353 | struct non_note *p = t->prev_non_note, *n; | |
354 | n = (struct non_note *) xmalloc(sizeof(struct non_note)); | |
355 | n->next = NULL; | |
356 | n->path = xstrdup(path); | |
357 | n->mode = mode; | |
358 | hashcpy(n->sha1, sha1); | |
359 | t->prev_non_note = n; | |
360 | ||
361 | if (!t->first_non_note) { | |
362 | t->first_non_note = n; | |
363 | return; | |
364 | } | |
365 | ||
366 | if (non_note_cmp(p, n) < 0) | |
367 | ; /* do nothing */ | |
368 | else if (non_note_cmp(t->first_non_note, n) <= 0) | |
369 | p = t->first_non_note; | |
370 | else { | |
371 | /* n sorts before t->first_non_note */ | |
372 | n->next = t->first_non_note; | |
373 | t->first_non_note = n; | |
374 | return; | |
375 | } | |
376 | ||
377 | /* n sorts equal or after p */ | |
378 | while (p->next && non_note_cmp(p->next, n) <= 0) | |
379 | p = p->next; | |
380 | ||
381 | if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */ | |
382 | assert(strcmp(p->path, n->path) == 0); | |
383 | p->mode = n->mode; | |
384 | hashcpy(p->sha1, n->sha1); | |
385 | free(n); | |
386 | t->prev_non_note = p; | |
387 | return; | |
388 | } | |
389 | ||
390 | /* n sorts between p and p->next */ | |
391 | n->next = p->next; | |
392 | p->next = n; | |
393 | } | |
394 | ||
395 | static void load_subtree(struct notes_tree *t, struct leaf_node *subtree, | |
396 | struct int_node *node, unsigned int n) | |
fd53c9eb | 397 | { |
a7e7eff6 | 398 | unsigned char object_sha1[20]; |
23123aec | 399 | unsigned int prefix_len; |
23123aec | 400 | void *buf; |
fd53c9eb JS |
401 | struct tree_desc desc; |
402 | struct name_entry entry; | |
851c2b37 JH |
403 | int len, path_len; |
404 | unsigned char type; | |
405 | struct leaf_node *l; | |
23123aec JH |
406 | |
407 | buf = fill_tree_descriptor(&desc, subtree->val_sha1); | |
408 | if (!buf) | |
409 | die("Could not read %s for notes-index", | |
410 | sha1_to_hex(subtree->val_sha1)); | |
411 | ||
412 | prefix_len = subtree->key_sha1[19]; | |
413 | assert(prefix_len * 2 >= n); | |
a7e7eff6 | 414 | memcpy(object_sha1, subtree->key_sha1, prefix_len); |
23123aec | 415 | while (tree_entry(&desc, &entry)) { |
851c2b37 JH |
416 | path_len = strlen(entry.path); |
417 | len = get_sha1_hex_segment(entry.path, path_len, | |
a7e7eff6 | 418 | object_sha1 + prefix_len, 20 - prefix_len); |
23123aec | 419 | if (len < 0) |
851c2b37 | 420 | goto handle_non_note; /* entry.path is not a SHA1 */ |
23123aec JH |
421 | len += prefix_len; |
422 | ||
423 | /* | |
a7e7eff6 | 424 | * If object SHA1 is complete (len == 20), assume note object |
851c2b37 JH |
425 | * If object SHA1 is incomplete (len < 20), and current |
426 | * component consists of 2 hex chars, assume note subtree | |
23123aec JH |
427 | */ |
428 | if (len <= 20) { | |
851c2b37 JH |
429 | type = PTR_TYPE_NOTE; |
430 | l = (struct leaf_node *) | |
23123aec | 431 | xcalloc(sizeof(struct leaf_node), 1); |
a7e7eff6 | 432 | hashcpy(l->key_sha1, object_sha1); |
23123aec JH |
433 | hashcpy(l->val_sha1, entry.sha1); |
434 | if (len < 20) { | |
851c2b37 JH |
435 | if (!S_ISDIR(entry.mode) || path_len != 2) |
436 | goto handle_non_note; /* not subtree */ | |
23123aec JH |
437 | l->key_sha1[19] = (unsigned char) len; |
438 | type = PTR_TYPE_SUBTREE; | |
439 | } | |
851c2b37 | 440 | note_tree_insert(t, node, n, l, type, |
73f464b5 | 441 | combine_notes_concatenate); |
23123aec | 442 | } |
851c2b37 JH |
443 | continue; |
444 | ||
445 | handle_non_note: | |
446 | /* | |
447 | * Determine full path for this non-note entry: | |
448 | * The filename is already found in entry.path, but the | |
449 | * directory part of the path must be deduced from the subtree | |
450 | * containing this entry. We assume here that the overall notes | |
451 | * tree follows a strict byte-based progressive fanout | |
452 | * structure (i.e. using 2/38, 2/2/36, etc. fanouts, and not | |
453 | * e.g. 4/36 fanout). This means that if a non-note is found at | |
454 | * path "dead/beef", the following code will register it as | |
455 | * being found on "de/ad/beef". | |
456 | * On the other hand, if you use such non-obvious non-note | |
457 | * paths in the middle of a notes tree, you deserve what's | |
458 | * coming to you ;). Note that for non-notes that are not | |
459 | * SHA1-like at the top level, there will be no problems. | |
460 | * | |
461 | * To conclude, it is strongly advised to make sure non-notes | |
462 | * have at least one non-hex character in the top-level path | |
463 | * component. | |
464 | */ | |
465 | { | |
466 | char non_note_path[PATH_MAX]; | |
467 | char *p = non_note_path; | |
468 | const char *q = sha1_to_hex(subtree->key_sha1); | |
469 | int i; | |
470 | for (i = 0; i < prefix_len; i++) { | |
471 | *p++ = *q++; | |
472 | *p++ = *q++; | |
473 | *p++ = '/'; | |
474 | } | |
475 | strcpy(p, entry.path); | |
476 | add_non_note(t, non_note_path, entry.mode, entry.sha1); | |
477 | } | |
23123aec JH |
478 | } |
479 | free(buf); | |
480 | } | |
481 | ||
73f77b90 JH |
482 | /* |
483 | * Determine optimal on-disk fanout for this part of the notes tree | |
484 | * | |
485 | * Given a (sub)tree and the level in the internal tree structure, determine | |
486 | * whether or not the given existing fanout should be expanded for this | |
487 | * (sub)tree. | |
488 | * | |
489 | * Values of the 'fanout' variable: | |
490 | * - 0: No fanout (all notes are stored directly in the root notes tree) | |
491 | * - 1: 2/38 fanout | |
492 | * - 2: 2/2/36 fanout | |
493 | * - 3: 2/2/2/34 fanout | |
494 | * etc. | |
495 | */ | |
496 | static unsigned char determine_fanout(struct int_node *tree, unsigned char n, | |
497 | unsigned char fanout) | |
498 | { | |
499 | /* | |
500 | * The following is a simple heuristic that works well in practice: | |
501 | * For each even-numbered 16-tree level (remember that each on-disk | |
502 | * fanout level corresponds to _two_ 16-tree levels), peek at all 16 | |
503 | * entries at that tree level. If all of them are either int_nodes or | |
504 | * subtree entries, then there are likely plenty of notes below this | |
505 | * level, so we return an incremented fanout. | |
506 | */ | |
507 | unsigned int i; | |
508 | if ((n % 2) || (n > 2 * fanout)) | |
509 | return fanout; | |
510 | for (i = 0; i < 16; i++) { | |
511 | switch (GET_PTR_TYPE(tree->a[i])) { | |
512 | case PTR_TYPE_SUBTREE: | |
513 | case PTR_TYPE_INTERNAL: | |
514 | continue; | |
515 | default: | |
516 | return fanout; | |
517 | } | |
518 | } | |
519 | return fanout + 1; | |
520 | } | |
521 | ||
522 | static void construct_path_with_fanout(const unsigned char *sha1, | |
523 | unsigned char fanout, char *path) | |
524 | { | |
525 | unsigned int i = 0, j = 0; | |
526 | const char *hex_sha1 = sha1_to_hex(sha1); | |
527 | assert(fanout < 20); | |
528 | while (fanout) { | |
529 | path[i++] = hex_sha1[j++]; | |
530 | path[i++] = hex_sha1[j++]; | |
531 | path[i++] = '/'; | |
532 | fanout--; | |
533 | } | |
534 | strcpy(path + i, hex_sha1 + j); | |
535 | } | |
536 | ||
851c2b37 JH |
537 | static int for_each_note_helper(struct notes_tree *t, struct int_node *tree, |
538 | unsigned char n, unsigned char fanout, int flags, | |
539 | each_note_fn fn, void *cb_data) | |
73f77b90 JH |
540 | { |
541 | unsigned int i; | |
542 | void *p; | |
543 | int ret = 0; | |
544 | struct leaf_node *l; | |
545 | static char path[40 + 19 + 1]; /* hex SHA1 + 19 * '/' + NUL */ | |
546 | ||
547 | fanout = determine_fanout(tree, n, fanout); | |
548 | for (i = 0; i < 16; i++) { | |
549 | redo: | |
550 | p = tree->a[i]; | |
551 | switch (GET_PTR_TYPE(p)) { | |
552 | case PTR_TYPE_INTERNAL: | |
553 | /* recurse into int_node */ | |
851c2b37 | 554 | ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1, |
73f77b90 JH |
555 | fanout, flags, fn, cb_data); |
556 | break; | |
557 | case PTR_TYPE_SUBTREE: | |
558 | l = (struct leaf_node *) CLR_PTR_TYPE(p); | |
559 | /* | |
560 | * Subtree entries in the note tree represent parts of | |
561 | * the note tree that have not yet been explored. There | |
562 | * is a direct relationship between subtree entries at | |
563 | * level 'n' in the tree, and the 'fanout' variable: | |
564 | * Subtree entries at level 'n <= 2 * fanout' should be | |
565 | * preserved, since they correspond exactly to a fanout | |
566 | * directory in the on-disk structure. However, subtree | |
567 | * entries at level 'n > 2 * fanout' should NOT be | |
568 | * preserved, but rather consolidated into the above | |
569 | * notes tree level. We achieve this by unconditionally | |
570 | * unpacking subtree entries that exist below the | |
571 | * threshold level at 'n = 2 * fanout'. | |
572 | */ | |
573 | if (n <= 2 * fanout && | |
574 | flags & FOR_EACH_NOTE_YIELD_SUBTREES) { | |
575 | /* invoke callback with subtree */ | |
576 | unsigned int path_len = | |
577 | l->key_sha1[19] * 2 + fanout; | |
578 | assert(path_len < 40 + 19); | |
579 | construct_path_with_fanout(l->key_sha1, fanout, | |
580 | path); | |
581 | /* Create trailing slash, if needed */ | |
582 | if (path[path_len - 1] != '/') | |
583 | path[path_len++] = '/'; | |
584 | path[path_len] = '\0'; | |
585 | ret = fn(l->key_sha1, l->val_sha1, path, | |
586 | cb_data); | |
587 | } | |
588 | if (n > fanout * 2 || | |
589 | !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) { | |
590 | /* unpack subtree and resume traversal */ | |
591 | tree->a[i] = NULL; | |
851c2b37 | 592 | load_subtree(t, l, tree, n); |
73f77b90 JH |
593 | free(l); |
594 | goto redo; | |
595 | } | |
596 | break; | |
597 | case PTR_TYPE_NOTE: | |
598 | l = (struct leaf_node *) CLR_PTR_TYPE(p); | |
599 | construct_path_with_fanout(l->key_sha1, fanout, path); | |
600 | ret = fn(l->key_sha1, l->val_sha1, path, cb_data); | |
601 | break; | |
602 | } | |
603 | if (ret) | |
604 | return ret; | |
605 | } | |
606 | return 0; | |
607 | } | |
608 | ||
61a7cca0 JH |
609 | struct tree_write_stack { |
610 | struct tree_write_stack *next; | |
611 | struct strbuf buf; | |
612 | char path[2]; /* path to subtree in next, if any */ | |
613 | }; | |
614 | ||
615 | static inline int matches_tree_write_stack(struct tree_write_stack *tws, | |
616 | const char *full_path) | |
617 | { | |
618 | return full_path[0] == tws->path[0] && | |
619 | full_path[1] == tws->path[1] && | |
620 | full_path[2] == '/'; | |
621 | } | |
622 | ||
623 | static void write_tree_entry(struct strbuf *buf, unsigned int mode, | |
624 | const char *path, unsigned int path_len, const | |
625 | unsigned char *sha1) | |
626 | { | |
627 | strbuf_addf(buf, "%06o %.*s%c", mode, path_len, path, '\0'); | |
628 | strbuf_add(buf, sha1, 20); | |
629 | } | |
630 | ||
631 | static void tree_write_stack_init_subtree(struct tree_write_stack *tws, | |
632 | const char *path) | |
633 | { | |
634 | struct tree_write_stack *n; | |
635 | assert(!tws->next); | |
636 | assert(tws->path[0] == '\0' && tws->path[1] == '\0'); | |
637 | n = (struct tree_write_stack *) | |
638 | xmalloc(sizeof(struct tree_write_stack)); | |
639 | n->next = NULL; | |
640 | strbuf_init(&n->buf, 256 * (32 + 40)); /* assume 256 entries per tree */ | |
641 | n->path[0] = n->path[1] = '\0'; | |
642 | tws->next = n; | |
643 | tws->path[0] = path[0]; | |
644 | tws->path[1] = path[1]; | |
645 | } | |
646 | ||
647 | static int tree_write_stack_finish_subtree(struct tree_write_stack *tws) | |
648 | { | |
649 | int ret; | |
650 | struct tree_write_stack *n = tws->next; | |
651 | unsigned char s[20]; | |
652 | if (n) { | |
653 | ret = tree_write_stack_finish_subtree(n); | |
654 | if (ret) | |
655 | return ret; | |
656 | ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s); | |
657 | if (ret) | |
658 | return ret; | |
659 | strbuf_release(&n->buf); | |
660 | free(n); | |
661 | tws->next = NULL; | |
662 | write_tree_entry(&tws->buf, 040000, tws->path, 2, s); | |
663 | tws->path[0] = tws->path[1] = '\0'; | |
664 | } | |
665 | return 0; | |
666 | } | |
667 | ||
668 | static int write_each_note_helper(struct tree_write_stack *tws, | |
669 | const char *path, unsigned int mode, | |
670 | const unsigned char *sha1) | |
671 | { | |
672 | size_t path_len = strlen(path); | |
673 | unsigned int n = 0; | |
674 | int ret; | |
675 | ||
676 | /* Determine common part of tree write stack */ | |
677 | while (tws && 3 * n < path_len && | |
678 | matches_tree_write_stack(tws, path + 3 * n)) { | |
679 | n++; | |
680 | tws = tws->next; | |
681 | } | |
682 | ||
683 | /* tws point to last matching tree_write_stack entry */ | |
684 | ret = tree_write_stack_finish_subtree(tws); | |
685 | if (ret) | |
686 | return ret; | |
687 | ||
688 | /* Start subtrees needed to satisfy path */ | |
689 | while (3 * n + 2 < path_len && path[3 * n + 2] == '/') { | |
690 | tree_write_stack_init_subtree(tws, path + 3 * n); | |
691 | n++; | |
692 | tws = tws->next; | |
693 | } | |
694 | ||
695 | /* There should be no more directory components in the given path */ | |
696 | assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL); | |
697 | ||
698 | /* Finally add given entry to the current tree object */ | |
699 | write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n), | |
700 | sha1); | |
701 | ||
702 | return 0; | |
703 | } | |
704 | ||
705 | struct write_each_note_data { | |
706 | struct tree_write_stack *root; | |
851c2b37 | 707 | struct non_note *next_non_note; |
61a7cca0 JH |
708 | }; |
709 | ||
851c2b37 JH |
710 | static int write_each_non_note_until(const char *note_path, |
711 | struct write_each_note_data *d) | |
712 | { | |
713 | struct non_note *n = d->next_non_note; | |
714 | int cmp, ret; | |
715 | while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) { | |
716 | if (note_path && cmp == 0) | |
717 | ; /* do nothing, prefer note to non-note */ | |
718 | else { | |
719 | ret = write_each_note_helper(d->root, n->path, n->mode, | |
720 | n->sha1); | |
721 | if (ret) | |
722 | return ret; | |
723 | } | |
724 | n = n->next; | |
725 | } | |
726 | d->next_non_note = n; | |
727 | return 0; | |
728 | } | |
729 | ||
61a7cca0 JH |
730 | static int write_each_note(const unsigned char *object_sha1, |
731 | const unsigned char *note_sha1, char *note_path, | |
732 | void *cb_data) | |
733 | { | |
734 | struct write_each_note_data *d = | |
735 | (struct write_each_note_data *) cb_data; | |
736 | size_t note_path_len = strlen(note_path); | |
737 | unsigned int mode = 0100644; | |
738 | ||
739 | if (note_path[note_path_len - 1] == '/') { | |
740 | /* subtree entry */ | |
741 | note_path_len--; | |
742 | note_path[note_path_len] = '\0'; | |
743 | mode = 040000; | |
744 | } | |
745 | assert(note_path_len <= 40 + 19); | |
746 | ||
851c2b37 JH |
747 | /* Weave non-note entries into note entries */ |
748 | return write_each_non_note_until(note_path, d) || | |
749 | write_each_note_helper(d->root, note_path, mode, note_sha1); | |
61a7cca0 JH |
750 | } |
751 | ||
73f464b5 JH |
752 | int combine_notes_concatenate(unsigned char *cur_sha1, |
753 | const unsigned char *new_sha1) | |
754 | { | |
755 | char *cur_msg = NULL, *new_msg = NULL, *buf; | |
756 | unsigned long cur_len, new_len, buf_len; | |
757 | enum object_type cur_type, new_type; | |
758 | int ret; | |
759 | ||
760 | /* read in both note blob objects */ | |
761 | if (!is_null_sha1(new_sha1)) | |
762 | new_msg = read_sha1_file(new_sha1, &new_type, &new_len); | |
763 | if (!new_msg || !new_len || new_type != OBJ_BLOB) { | |
764 | free(new_msg); | |
765 | return 0; | |
766 | } | |
767 | if (!is_null_sha1(cur_sha1)) | |
768 | cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len); | |
769 | if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) { | |
770 | free(cur_msg); | |
771 | free(new_msg); | |
772 | hashcpy(cur_sha1, new_sha1); | |
773 | return 0; | |
774 | } | |
775 | ||
776 | /* we will separate the notes by a newline anyway */ | |
777 | if (cur_msg[cur_len - 1] == '\n') | |
778 | cur_len--; | |
779 | ||
780 | /* concatenate cur_msg and new_msg into buf */ | |
781 | buf_len = cur_len + 1 + new_len; | |
782 | buf = (char *) xmalloc(buf_len); | |
783 | memcpy(buf, cur_msg, cur_len); | |
784 | buf[cur_len] = '\n'; | |
785 | memcpy(buf + cur_len + 1, new_msg, new_len); | |
786 | free(cur_msg); | |
787 | free(new_msg); | |
788 | ||
789 | /* create a new blob object from buf */ | |
790 | ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1); | |
791 | free(buf); | |
792 | return ret; | |
793 | } | |
794 | ||
795 | int combine_notes_overwrite(unsigned char *cur_sha1, | |
796 | const unsigned char *new_sha1) | |
797 | { | |
798 | hashcpy(cur_sha1, new_sha1); | |
799 | return 0; | |
800 | } | |
801 | ||
802 | int combine_notes_ignore(unsigned char *cur_sha1, | |
803 | const unsigned char *new_sha1) | |
804 | { | |
805 | return 0; | |
806 | } | |
807 | ||
808 | void init_notes(struct notes_tree *t, const char *notes_ref, | |
809 | combine_notes_fn combine_notes, int flags) | |
23123aec | 810 | { |
a7e7eff6 | 811 | unsigned char sha1[20], object_sha1[20]; |
23123aec JH |
812 | unsigned mode; |
813 | struct leaf_node root_tree; | |
fd53c9eb | 814 | |
cd305392 JH |
815 | if (!t) |
816 | t = &default_notes_tree; | |
817 | assert(!t->initialized); | |
709f79b0 JH |
818 | |
819 | if (!notes_ref) | |
820 | notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT); | |
821 | if (!notes_ref) | |
822 | notes_ref = notes_ref_name; /* value of core.notesRef config */ | |
823 | if (!notes_ref) | |
824 | notes_ref = GIT_NOTES_DEFAULT_REF; | |
825 | ||
73f464b5 JH |
826 | if (!combine_notes) |
827 | combine_notes = combine_notes_concatenate; | |
828 | ||
cd305392 | 829 | t->root = (struct int_node *) xcalloc(sizeof(struct int_node), 1); |
851c2b37 JH |
830 | t->first_non_note = NULL; |
831 | t->prev_non_note = NULL; | |
cd305392 | 832 | t->ref = notes_ref ? xstrdup(notes_ref) : NULL; |
73f464b5 | 833 | t->combine_notes = combine_notes; |
cd305392 JH |
834 | t->initialized = 1; |
835 | ||
709f79b0 JH |
836 | if (flags & NOTES_INIT_EMPTY || !notes_ref || |
837 | read_ref(notes_ref, object_sha1)) | |
fd53c9eb | 838 | return; |
709f79b0 JH |
839 | if (get_tree_entry(object_sha1, "", sha1, &mode)) |
840 | die("Failed to read notes tree referenced by %s (%s)", | |
841 | notes_ref, object_sha1); | |
fd53c9eb | 842 | |
23123aec JH |
843 | hashclr(root_tree.key_sha1); |
844 | hashcpy(root_tree.val_sha1, sha1); | |
851c2b37 | 845 | load_subtree(t, &root_tree, t->root, 0); |
fd53c9eb JS |
846 | } |
847 | ||
cd305392 | 848 | void add_note(struct notes_tree *t, const unsigned char *object_sha1, |
73f464b5 | 849 | const unsigned char *note_sha1, combine_notes_fn combine_notes) |
2626b536 JH |
850 | { |
851 | struct leaf_node *l; | |
852 | ||
cd305392 JH |
853 | if (!t) |
854 | t = &default_notes_tree; | |
855 | assert(t->initialized); | |
73f464b5 JH |
856 | if (!combine_notes) |
857 | combine_notes = t->combine_notes; | |
2626b536 JH |
858 | l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node)); |
859 | hashcpy(l->key_sha1, object_sha1); | |
860 | hashcpy(l->val_sha1, note_sha1); | |
851c2b37 | 861 | note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes); |
2626b536 JH |
862 | } |
863 | ||
cd305392 | 864 | void remove_note(struct notes_tree *t, const unsigned char *object_sha1) |
1ec666b0 JH |
865 | { |
866 | struct leaf_node l; | |
867 | ||
cd305392 JH |
868 | if (!t) |
869 | t = &default_notes_tree; | |
870 | assert(t->initialized); | |
1ec666b0 JH |
871 | hashcpy(l.key_sha1, object_sha1); |
872 | hashclr(l.val_sha1); | |
cd305392 | 873 | return note_tree_remove(t, t->root, 0, &l); |
1ec666b0 JH |
874 | } |
875 | ||
cd305392 JH |
876 | const unsigned char *get_note(struct notes_tree *t, |
877 | const unsigned char *object_sha1) | |
fd53c9eb | 878 | { |
9b391f21 JH |
879 | struct leaf_node *found; |
880 | ||
cd305392 JH |
881 | if (!t) |
882 | t = &default_notes_tree; | |
883 | assert(t->initialized); | |
851c2b37 | 884 | found = note_tree_find(t, t->root, 0, object_sha1); |
9b391f21 | 885 | return found ? found->val_sha1 : NULL; |
fd53c9eb | 886 | } |
a97a7468 | 887 | |
cd305392 JH |
888 | int for_each_note(struct notes_tree *t, int flags, each_note_fn fn, |
889 | void *cb_data) | |
73f77b90 | 890 | { |
cd305392 JH |
891 | if (!t) |
892 | t = &default_notes_tree; | |
893 | assert(t->initialized); | |
851c2b37 | 894 | return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data); |
73f77b90 JH |
895 | } |
896 | ||
cd305392 | 897 | int write_notes_tree(struct notes_tree *t, unsigned char *result) |
61a7cca0 JH |
898 | { |
899 | struct tree_write_stack root; | |
900 | struct write_each_note_data cb_data; | |
901 | int ret; | |
902 | ||
cd305392 JH |
903 | if (!t) |
904 | t = &default_notes_tree; | |
905 | assert(t->initialized); | |
61a7cca0 JH |
906 | |
907 | /* Prepare for traversal of current notes tree */ | |
908 | root.next = NULL; /* last forward entry in list is grounded */ | |
909 | strbuf_init(&root.buf, 256 * (32 + 40)); /* assume 256 entries */ | |
910 | root.path[0] = root.path[1] = '\0'; | |
911 | cb_data.root = &root; | |
851c2b37 | 912 | cb_data.next_non_note = t->first_non_note; |
61a7cca0 JH |
913 | |
914 | /* Write tree objects representing current notes tree */ | |
cd305392 | 915 | ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES | |
61a7cca0 JH |
916 | FOR_EACH_NOTE_YIELD_SUBTREES, |
917 | write_each_note, &cb_data) || | |
851c2b37 | 918 | write_each_non_note_until(NULL, &cb_data) || |
61a7cca0 JH |
919 | tree_write_stack_finish_subtree(&root) || |
920 | write_sha1_file(root.buf.buf, root.buf.len, tree_type, result); | |
921 | strbuf_release(&root.buf); | |
922 | return ret; | |
923 | } | |
924 | ||
cd305392 | 925 | void free_notes(struct notes_tree *t) |
27d57564 | 926 | { |
cd305392 JH |
927 | if (!t) |
928 | t = &default_notes_tree; | |
929 | if (t->root) | |
930 | note_tree_free(t->root); | |
931 | free(t->root); | |
851c2b37 JH |
932 | while (t->first_non_note) { |
933 | t->prev_non_note = t->first_non_note->next; | |
934 | free(t->first_non_note->path); | |
935 | free(t->first_non_note); | |
936 | t->first_non_note = t->prev_non_note; | |
937 | } | |
cd305392 JH |
938 | free(t->ref); |
939 | memset(t, 0, sizeof(struct notes_tree)); | |
27d57564 JH |
940 | } |
941 | ||
cd305392 JH |
942 | void format_note(struct notes_tree *t, const unsigned char *object_sha1, |
943 | struct strbuf *sb, const char *output_encoding, int flags) | |
a97a7468 JS |
944 | { |
945 | static const char utf8[] = "utf-8"; | |
9b391f21 | 946 | const unsigned char *sha1; |
a97a7468 JS |
947 | char *msg, *msg_p; |
948 | unsigned long linelen, msglen; | |
949 | enum object_type type; | |
950 | ||
cd305392 JH |
951 | if (!t) |
952 | t = &default_notes_tree; | |
953 | if (!t->initialized) | |
73f464b5 | 954 | init_notes(t, NULL, NULL, 0); |
a97a7468 | 955 | |
cd305392 | 956 | sha1 = get_note(t, object_sha1); |
fd53c9eb | 957 | if (!sha1) |
a97a7468 JS |
958 | return; |
959 | ||
960 | if (!(msg = read_sha1_file(sha1, &type, &msglen)) || !msglen || | |
961 | type != OBJ_BLOB) { | |
962 | free(msg); | |
963 | return; | |
964 | } | |
965 | ||
966 | if (output_encoding && *output_encoding && | |
967 | strcmp(utf8, output_encoding)) { | |
968 | char *reencoded = reencode_string(msg, output_encoding, utf8); | |
969 | if (reencoded) { | |
970 | free(msg); | |
971 | msg = reencoded; | |
972 | msglen = strlen(msg); | |
973 | } | |
974 | } | |
975 | ||
976 | /* we will end the annotation by a newline anyway */ | |
977 | if (msglen && msg[msglen - 1] == '\n') | |
978 | msglen--; | |
979 | ||
c56fcc89 JH |
980 | if (flags & NOTES_SHOW_HEADER) |
981 | strbuf_addstr(sb, "\nNotes:\n"); | |
a97a7468 JS |
982 | |
983 | for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) { | |
984 | linelen = strchrnul(msg_p, '\n') - msg_p; | |
985 | ||
c56fcc89 JH |
986 | if (flags & NOTES_INDENT) |
987 | strbuf_addstr(sb, " "); | |
a97a7468 JS |
988 | strbuf_add(sb, msg_p, linelen); |
989 | strbuf_addch(sb, '\n'); | |
990 | } | |
991 | ||
992 | free(msg); | |
993 | } |