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a97a7468 | 1 | #include "cache.h" |
a97a7468 | 2 | #include "notes.h" |
61a7cca0 | 3 | #include "tree.h" |
a97a7468 JS |
4 | #include "utf8.h" |
5 | #include "strbuf.h" | |
fd53c9eb JS |
6 | #include "tree-walk.h" |
7 | ||
23123aec JH |
8 | /* |
9 | * Use a non-balancing simple 16-tree structure with struct int_node as | |
10 | * internal nodes, and struct leaf_node as leaf nodes. Each int_node has a | |
11 | * 16-array of pointers to its children. | |
12 | * The bottom 2 bits of each pointer is used to identify the pointer type | |
13 | * - ptr & 3 == 0 - NULL pointer, assert(ptr == NULL) | |
14 | * - ptr & 3 == 1 - pointer to next internal node - cast to struct int_node * | |
15 | * - ptr & 3 == 2 - pointer to note entry - cast to struct leaf_node * | |
16 | * - ptr & 3 == 3 - pointer to subtree entry - cast to struct leaf_node * | |
17 | * | |
18 | * The root node is a statically allocated struct int_node. | |
19 | */ | |
20 | struct int_node { | |
21 | void *a[16]; | |
fd53c9eb JS |
22 | }; |
23 | ||
23123aec JH |
24 | /* |
25 | * Leaf nodes come in two variants, note entries and subtree entries, | |
26 | * distinguished by the LSb of the leaf node pointer (see above). | |
a7e7eff6 | 27 | * As a note entry, the key is the SHA1 of the referenced object, and the |
23123aec JH |
28 | * value is the SHA1 of the note object. |
29 | * As a subtree entry, the key is the prefix SHA1 (w/trailing NULs) of the | |
a7e7eff6 | 30 | * referenced object, using the last byte of the key to store the length of |
23123aec JH |
31 | * the prefix. The value is the SHA1 of the tree object containing the notes |
32 | * subtree. | |
33 | */ | |
34 | struct leaf_node { | |
35 | unsigned char key_sha1[20]; | |
36 | unsigned char val_sha1[20]; | |
fd53c9eb | 37 | }; |
a97a7468 | 38 | |
23123aec JH |
39 | #define PTR_TYPE_NULL 0 |
40 | #define PTR_TYPE_INTERNAL 1 | |
41 | #define PTR_TYPE_NOTE 2 | |
42 | #define PTR_TYPE_SUBTREE 3 | |
fd53c9eb | 43 | |
23123aec JH |
44 | #define GET_PTR_TYPE(ptr) ((uintptr_t) (ptr) & 3) |
45 | #define CLR_PTR_TYPE(ptr) ((void *) ((uintptr_t) (ptr) & ~3)) | |
46 | #define SET_PTR_TYPE(ptr, type) ((void *) ((uintptr_t) (ptr) | (type))) | |
fd53c9eb | 47 | |
1ec666b0 | 48 | #define GET_NIBBLE(n, sha1) (((sha1[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f) |
fd53c9eb | 49 | |
23123aec JH |
50 | #define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \ |
51 | (memcmp(key_sha1, subtree_sha1, subtree_sha1[19])) | |
fd53c9eb | 52 | |
cd305392 | 53 | struct notes_tree default_notes_tree; |
23123aec JH |
54 | |
55 | static void load_subtree(struct leaf_node *subtree, struct int_node *node, | |
56 | unsigned int n); | |
57 | ||
58 | /* | |
ef8db638 | 59 | * Search the tree until the appropriate location for the given key is found: |
23123aec | 60 | * 1. Start at the root node, with n = 0 |
ef8db638 JH |
61 | * 2. If a[0] at the current level is a matching subtree entry, unpack that |
62 | * subtree entry and remove it; restart search at the current level. | |
63 | * 3. Use the nth nibble of the key as an index into a: | |
64 | * - If a[n] is an int_node, recurse from #2 into that node and increment n | |
23123aec JH |
65 | * - If a matching subtree entry, unpack that subtree entry (and remove it); |
66 | * restart search at the current level. | |
ef8db638 JH |
67 | * - Otherwise, we have found one of the following: |
68 | * - a subtree entry which does not match the key | |
69 | * - a note entry which may or may not match the key | |
70 | * - an unused leaf node (NULL) | |
71 | * In any case, set *tree and *n, and return pointer to the tree location. | |
23123aec | 72 | */ |
ef8db638 JH |
73 | static void **note_tree_search(struct int_node **tree, |
74 | unsigned char *n, const unsigned char *key_sha1) | |
23123aec JH |
75 | { |
76 | struct leaf_node *l; | |
ef8db638 JH |
77 | unsigned char i; |
78 | void *p = (*tree)->a[0]; | |
23123aec | 79 | |
ef8db638 JH |
80 | if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) { |
81 | l = (struct leaf_node *) CLR_PTR_TYPE(p); | |
82 | if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) { | |
83 | /* unpack tree and resume search */ | |
84 | (*tree)->a[0] = NULL; | |
85 | load_subtree(l, *tree, *n); | |
86 | free(l); | |
87 | return note_tree_search(tree, n, key_sha1); | |
88 | } | |
89 | } | |
90 | ||
91 | i = GET_NIBBLE(*n, key_sha1); | |
92 | p = (*tree)->a[i]; | |
0ab1faae | 93 | switch (GET_PTR_TYPE(p)) { |
23123aec | 94 | case PTR_TYPE_INTERNAL: |
ef8db638 JH |
95 | *tree = CLR_PTR_TYPE(p); |
96 | (*n)++; | |
97 | return note_tree_search(tree, n, key_sha1); | |
23123aec JH |
98 | case PTR_TYPE_SUBTREE: |
99 | l = (struct leaf_node *) CLR_PTR_TYPE(p); | |
100 | if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) { | |
101 | /* unpack tree and resume search */ | |
ef8db638 JH |
102 | (*tree)->a[i] = NULL; |
103 | load_subtree(l, *tree, *n); | |
23123aec | 104 | free(l); |
ef8db638 | 105 | return note_tree_search(tree, n, key_sha1); |
23123aec | 106 | } |
ef8db638 | 107 | /* fall through */ |
23123aec | 108 | default: |
ef8db638 | 109 | return &((*tree)->a[i]); |
fd53c9eb | 110 | } |
ef8db638 | 111 | } |
23123aec | 112 | |
ef8db638 JH |
113 | /* |
114 | * To find a leaf_node: | |
115 | * Search to the tree location appropriate for the given key: | |
116 | * If a note entry with matching key, return the note entry, else return NULL. | |
117 | */ | |
118 | static struct leaf_node *note_tree_find(struct int_node *tree, unsigned char n, | |
119 | const unsigned char *key_sha1) | |
120 | { | |
121 | void **p = note_tree_search(&tree, &n, key_sha1); | |
122 | if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) { | |
123 | struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p); | |
124 | if (!hashcmp(key_sha1, l->key_sha1)) | |
125 | return l; | |
23123aec JH |
126 | } |
127 | return NULL; | |
fd53c9eb JS |
128 | } |
129 | ||
ef8db638 JH |
130 | /* Create a new blob object by concatenating the two given blob objects */ |
131 | static int concatenate_notes(unsigned char *cur_sha1, | |
132 | const unsigned char *new_sha1) | |
133 | { | |
134 | char *cur_msg, *new_msg, *buf; | |
135 | unsigned long cur_len, new_len, buf_len; | |
136 | enum object_type cur_type, new_type; | |
137 | int ret; | |
138 | ||
139 | /* read in both note blob objects */ | |
140 | new_msg = read_sha1_file(new_sha1, &new_type, &new_len); | |
141 | if (!new_msg || !new_len || new_type != OBJ_BLOB) { | |
142 | free(new_msg); | |
143 | return 0; | |
144 | } | |
145 | cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len); | |
146 | if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) { | |
147 | free(cur_msg); | |
148 | free(new_msg); | |
149 | hashcpy(cur_sha1, new_sha1); | |
150 | return 0; | |
151 | } | |
152 | ||
153 | /* we will separate the notes by a newline anyway */ | |
154 | if (cur_msg[cur_len - 1] == '\n') | |
155 | cur_len--; | |
156 | ||
157 | /* concatenate cur_msg and new_msg into buf */ | |
158 | buf_len = cur_len + 1 + new_len; | |
159 | buf = (char *) xmalloc(buf_len); | |
160 | memcpy(buf, cur_msg, cur_len); | |
161 | buf[cur_len] = '\n'; | |
162 | memcpy(buf + cur_len + 1, new_msg, new_len); | |
163 | ||
164 | free(cur_msg); | |
165 | free(new_msg); | |
166 | ||
167 | /* create a new blob object from buf */ | |
168 | ret = write_sha1_file(buf, buf_len, "blob", cur_sha1); | |
169 | free(buf); | |
170 | return ret; | |
171 | } | |
172 | ||
23123aec JH |
173 | /* |
174 | * To insert a leaf_node: | |
ef8db638 JH |
175 | * Search to the tree location appropriate for the given leaf_node's key: |
176 | * - If location is unused (NULL), store the tweaked pointer directly there | |
177 | * - If location holds a note entry that matches the note-to-be-inserted, then | |
178 | * concatenate the two notes. | |
179 | * - If location holds a note entry that matches the subtree-to-be-inserted, | |
180 | * then unpack the subtree-to-be-inserted into the location. | |
181 | * - If location holds a matching subtree entry, unpack the subtree at that | |
182 | * location, and restart the insert operation from that level. | |
183 | * - Else, create a new int_node, holding both the node-at-location and the | |
184 | * node-to-be-inserted, and store the new int_node into the location. | |
23123aec | 185 | */ |
ef8db638 JH |
186 | static void note_tree_insert(struct int_node *tree, unsigned char n, |
187 | struct leaf_node *entry, unsigned char type) | |
fd53c9eb | 188 | { |
23123aec | 189 | struct int_node *new_node; |
ef8db638 JH |
190 | struct leaf_node *l; |
191 | void **p = note_tree_search(&tree, &n, entry->key_sha1); | |
192 | ||
193 | assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */ | |
194 | l = (struct leaf_node *) CLR_PTR_TYPE(*p); | |
0ab1faae | 195 | switch (GET_PTR_TYPE(*p)) { |
23123aec | 196 | case PTR_TYPE_NULL: |
ef8db638 JH |
197 | assert(!*p); |
198 | *p = SET_PTR_TYPE(entry, type); | |
199 | return; | |
200 | case PTR_TYPE_NOTE: | |
201 | switch (type) { | |
202 | case PTR_TYPE_NOTE: | |
203 | if (!hashcmp(l->key_sha1, entry->key_sha1)) { | |
204 | /* skip concatenation if l == entry */ | |
205 | if (!hashcmp(l->val_sha1, entry->val_sha1)) | |
206 | return; | |
207 | ||
208 | if (concatenate_notes(l->val_sha1, | |
209 | entry->val_sha1)) | |
210 | die("failed to concatenate note %s " | |
a7e7eff6 | 211 | "into note %s for object %s", |
ef8db638 JH |
212 | sha1_to_hex(entry->val_sha1), |
213 | sha1_to_hex(l->val_sha1), | |
214 | sha1_to_hex(l->key_sha1)); | |
215 | free(entry); | |
216 | return; | |
217 | } | |
218 | break; | |
219 | case PTR_TYPE_SUBTREE: | |
220 | if (!SUBTREE_SHA1_PREFIXCMP(l->key_sha1, | |
221 | entry->key_sha1)) { | |
222 | /* unpack 'entry' */ | |
223 | load_subtree(entry, tree, n); | |
224 | free(entry); | |
225 | return; | |
226 | } | |
227 | break; | |
228 | } | |
229 | break; | |
230 | case PTR_TYPE_SUBTREE: | |
231 | if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) { | |
232 | /* unpack 'l' and restart insert */ | |
233 | *p = NULL; | |
234 | load_subtree(l, tree, n); | |
235 | free(l); | |
236 | note_tree_insert(tree, n, entry, type); | |
237 | return; | |
23123aec | 238 | } |
ef8db638 | 239 | break; |
fd53c9eb | 240 | } |
ef8db638 JH |
241 | |
242 | /* non-matching leaf_node */ | |
243 | assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE || | |
244 | GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE); | |
245 | new_node = (struct int_node *) xcalloc(sizeof(struct int_node), 1); | |
246 | note_tree_insert(new_node, n + 1, l, GET_PTR_TYPE(*p)); | |
247 | *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL); | |
248 | note_tree_insert(new_node, n + 1, entry, type); | |
23123aec | 249 | } |
fd53c9eb | 250 | |
1ec666b0 JH |
251 | /* |
252 | * How to consolidate an int_node: | |
253 | * If there are > 1 non-NULL entries, give up and return non-zero. | |
254 | * Otherwise replace the int_node at the given index in the given parent node | |
255 | * with the only entry (or a NULL entry if no entries) from the given tree, | |
256 | * and return 0. | |
257 | */ | |
258 | static int note_tree_consolidate(struct int_node *tree, | |
259 | struct int_node *parent, unsigned char index) | |
260 | { | |
261 | unsigned int i; | |
262 | void *p = NULL; | |
263 | ||
264 | assert(tree && parent); | |
265 | assert(CLR_PTR_TYPE(parent->a[index]) == tree); | |
266 | ||
267 | for (i = 0; i < 16; i++) { | |
268 | if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) { | |
269 | if (p) /* more than one entry */ | |
270 | return -2; | |
271 | p = tree->a[i]; | |
272 | } | |
273 | } | |
274 | ||
275 | /* replace tree with p in parent[index] */ | |
276 | parent->a[index] = p; | |
277 | free(tree); | |
278 | return 0; | |
279 | } | |
280 | ||
281 | /* | |
282 | * To remove a leaf_node: | |
283 | * Search to the tree location appropriate for the given leaf_node's key: | |
284 | * - If location does not hold a matching entry, abort and do nothing. | |
285 | * - Replace the matching leaf_node with a NULL entry (and free the leaf_node). | |
286 | * - Consolidate int_nodes repeatedly, while walking up the tree towards root. | |
287 | */ | |
cd305392 JH |
288 | static void note_tree_remove(struct notes_tree *t, struct int_node *tree, |
289 | unsigned char n, struct leaf_node *entry) | |
1ec666b0 JH |
290 | { |
291 | struct leaf_node *l; | |
292 | struct int_node *parent_stack[20]; | |
293 | unsigned char i, j; | |
294 | void **p = note_tree_search(&tree, &n, entry->key_sha1); | |
295 | ||
296 | assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */ | |
297 | if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE) | |
298 | return; /* type mismatch, nothing to remove */ | |
299 | l = (struct leaf_node *) CLR_PTR_TYPE(*p); | |
300 | if (hashcmp(l->key_sha1, entry->key_sha1)) | |
301 | return; /* key mismatch, nothing to remove */ | |
302 | ||
303 | /* we have found a matching entry */ | |
304 | free(l); | |
305 | *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL); | |
306 | ||
307 | /* consolidate this tree level, and parent levels, if possible */ | |
308 | if (!n) | |
309 | return; /* cannot consolidate top level */ | |
310 | /* first, build stack of ancestors between root and current node */ | |
cd305392 | 311 | parent_stack[0] = t->root; |
1ec666b0 JH |
312 | for (i = 0; i < n; i++) { |
313 | j = GET_NIBBLE(i, entry->key_sha1); | |
314 | parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]); | |
315 | } | |
316 | assert(i == n && parent_stack[i] == tree); | |
317 | /* next, unwind stack until note_tree_consolidate() is done */ | |
318 | while (i > 0 && | |
319 | !note_tree_consolidate(parent_stack[i], parent_stack[i - 1], | |
320 | GET_NIBBLE(i - 1, entry->key_sha1))) | |
321 | i--; | |
322 | } | |
323 | ||
23123aec JH |
324 | /* Free the entire notes data contained in the given tree */ |
325 | static void note_tree_free(struct int_node *tree) | |
326 | { | |
327 | unsigned int i; | |
328 | for (i = 0; i < 16; i++) { | |
329 | void *p = tree->a[i]; | |
0ab1faae | 330 | switch (GET_PTR_TYPE(p)) { |
23123aec JH |
331 | case PTR_TYPE_INTERNAL: |
332 | note_tree_free(CLR_PTR_TYPE(p)); | |
333 | /* fall through */ | |
334 | case PTR_TYPE_NOTE: | |
335 | case PTR_TYPE_SUBTREE: | |
336 | free(CLR_PTR_TYPE(p)); | |
337 | } | |
fd53c9eb | 338 | } |
23123aec | 339 | } |
fd53c9eb | 340 | |
23123aec JH |
341 | /* |
342 | * Convert a partial SHA1 hex string to the corresponding partial SHA1 value. | |
343 | * - hex - Partial SHA1 segment in ASCII hex format | |
344 | * - hex_len - Length of above segment. Must be multiple of 2 between 0 and 40 | |
345 | * - sha1 - Partial SHA1 value is written here | |
346 | * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20 | |
0ab1faae | 347 | * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format)). |
23123aec JH |
348 | * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2). |
349 | * Pads sha1 with NULs up to sha1_len (not included in returned length). | |
350 | */ | |
351 | static int get_sha1_hex_segment(const char *hex, unsigned int hex_len, | |
352 | unsigned char *sha1, unsigned int sha1_len) | |
353 | { | |
354 | unsigned int i, len = hex_len >> 1; | |
355 | if (hex_len % 2 != 0 || len > sha1_len) | |
356 | return -1; | |
357 | for (i = 0; i < len; i++) { | |
358 | unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]); | |
359 | if (val & ~0xff) | |
360 | return -1; | |
361 | *sha1++ = val; | |
362 | hex += 2; | |
363 | } | |
364 | for (; i < sha1_len; i++) | |
365 | *sha1++ = 0; | |
366 | return len; | |
fd53c9eb JS |
367 | } |
368 | ||
23123aec JH |
369 | static void load_subtree(struct leaf_node *subtree, struct int_node *node, |
370 | unsigned int n) | |
fd53c9eb | 371 | { |
a7e7eff6 | 372 | unsigned char object_sha1[20]; |
23123aec | 373 | unsigned int prefix_len; |
23123aec | 374 | void *buf; |
fd53c9eb JS |
375 | struct tree_desc desc; |
376 | struct name_entry entry; | |
23123aec JH |
377 | |
378 | buf = fill_tree_descriptor(&desc, subtree->val_sha1); | |
379 | if (!buf) | |
380 | die("Could not read %s for notes-index", | |
381 | sha1_to_hex(subtree->val_sha1)); | |
382 | ||
383 | prefix_len = subtree->key_sha1[19]; | |
384 | assert(prefix_len * 2 >= n); | |
a7e7eff6 | 385 | memcpy(object_sha1, subtree->key_sha1, prefix_len); |
23123aec JH |
386 | while (tree_entry(&desc, &entry)) { |
387 | int len = get_sha1_hex_segment(entry.path, strlen(entry.path), | |
a7e7eff6 | 388 | object_sha1 + prefix_len, 20 - prefix_len); |
23123aec JH |
389 | if (len < 0) |
390 | continue; /* entry.path is not a SHA1 sum. Skip */ | |
391 | len += prefix_len; | |
392 | ||
393 | /* | |
a7e7eff6 JH |
394 | * If object SHA1 is complete (len == 20), assume note object |
395 | * If object SHA1 is incomplete (len < 20), assume note subtree | |
23123aec JH |
396 | */ |
397 | if (len <= 20) { | |
398 | unsigned char type = PTR_TYPE_NOTE; | |
399 | struct leaf_node *l = (struct leaf_node *) | |
400 | xcalloc(sizeof(struct leaf_node), 1); | |
a7e7eff6 | 401 | hashcpy(l->key_sha1, object_sha1); |
23123aec JH |
402 | hashcpy(l->val_sha1, entry.sha1); |
403 | if (len < 20) { | |
488bdf2e JH |
404 | if (!S_ISDIR(entry.mode)) |
405 | continue; /* entry cannot be subtree */ | |
23123aec JH |
406 | l->key_sha1[19] = (unsigned char) len; |
407 | type = PTR_TYPE_SUBTREE; | |
408 | } | |
ef8db638 | 409 | note_tree_insert(node, n, l, type); |
23123aec JH |
410 | } |
411 | } | |
412 | free(buf); | |
413 | } | |
414 | ||
73f77b90 JH |
415 | /* |
416 | * Determine optimal on-disk fanout for this part of the notes tree | |
417 | * | |
418 | * Given a (sub)tree and the level in the internal tree structure, determine | |
419 | * whether or not the given existing fanout should be expanded for this | |
420 | * (sub)tree. | |
421 | * | |
422 | * Values of the 'fanout' variable: | |
423 | * - 0: No fanout (all notes are stored directly in the root notes tree) | |
424 | * - 1: 2/38 fanout | |
425 | * - 2: 2/2/36 fanout | |
426 | * - 3: 2/2/2/34 fanout | |
427 | * etc. | |
428 | */ | |
429 | static unsigned char determine_fanout(struct int_node *tree, unsigned char n, | |
430 | unsigned char fanout) | |
431 | { | |
432 | /* | |
433 | * The following is a simple heuristic that works well in practice: | |
434 | * For each even-numbered 16-tree level (remember that each on-disk | |
435 | * fanout level corresponds to _two_ 16-tree levels), peek at all 16 | |
436 | * entries at that tree level. If all of them are either int_nodes or | |
437 | * subtree entries, then there are likely plenty of notes below this | |
438 | * level, so we return an incremented fanout. | |
439 | */ | |
440 | unsigned int i; | |
441 | if ((n % 2) || (n > 2 * fanout)) | |
442 | return fanout; | |
443 | for (i = 0; i < 16; i++) { | |
444 | switch (GET_PTR_TYPE(tree->a[i])) { | |
445 | case PTR_TYPE_SUBTREE: | |
446 | case PTR_TYPE_INTERNAL: | |
447 | continue; | |
448 | default: | |
449 | return fanout; | |
450 | } | |
451 | } | |
452 | return fanout + 1; | |
453 | } | |
454 | ||
455 | static void construct_path_with_fanout(const unsigned char *sha1, | |
456 | unsigned char fanout, char *path) | |
457 | { | |
458 | unsigned int i = 0, j = 0; | |
459 | const char *hex_sha1 = sha1_to_hex(sha1); | |
460 | assert(fanout < 20); | |
461 | while (fanout) { | |
462 | path[i++] = hex_sha1[j++]; | |
463 | path[i++] = hex_sha1[j++]; | |
464 | path[i++] = '/'; | |
465 | fanout--; | |
466 | } | |
467 | strcpy(path + i, hex_sha1 + j); | |
468 | } | |
469 | ||
470 | static int for_each_note_helper(struct int_node *tree, unsigned char n, | |
471 | unsigned char fanout, int flags, each_note_fn fn, | |
472 | void *cb_data) | |
473 | { | |
474 | unsigned int i; | |
475 | void *p; | |
476 | int ret = 0; | |
477 | struct leaf_node *l; | |
478 | static char path[40 + 19 + 1]; /* hex SHA1 + 19 * '/' + NUL */ | |
479 | ||
480 | fanout = determine_fanout(tree, n, fanout); | |
481 | for (i = 0; i < 16; i++) { | |
482 | redo: | |
483 | p = tree->a[i]; | |
484 | switch (GET_PTR_TYPE(p)) { | |
485 | case PTR_TYPE_INTERNAL: | |
486 | /* recurse into int_node */ | |
487 | ret = for_each_note_helper(CLR_PTR_TYPE(p), n + 1, | |
488 | fanout, flags, fn, cb_data); | |
489 | break; | |
490 | case PTR_TYPE_SUBTREE: | |
491 | l = (struct leaf_node *) CLR_PTR_TYPE(p); | |
492 | /* | |
493 | * Subtree entries in the note tree represent parts of | |
494 | * the note tree that have not yet been explored. There | |
495 | * is a direct relationship between subtree entries at | |
496 | * level 'n' in the tree, and the 'fanout' variable: | |
497 | * Subtree entries at level 'n <= 2 * fanout' should be | |
498 | * preserved, since they correspond exactly to a fanout | |
499 | * directory in the on-disk structure. However, subtree | |
500 | * entries at level 'n > 2 * fanout' should NOT be | |
501 | * preserved, but rather consolidated into the above | |
502 | * notes tree level. We achieve this by unconditionally | |
503 | * unpacking subtree entries that exist below the | |
504 | * threshold level at 'n = 2 * fanout'. | |
505 | */ | |
506 | if (n <= 2 * fanout && | |
507 | flags & FOR_EACH_NOTE_YIELD_SUBTREES) { | |
508 | /* invoke callback with subtree */ | |
509 | unsigned int path_len = | |
510 | l->key_sha1[19] * 2 + fanout; | |
511 | assert(path_len < 40 + 19); | |
512 | construct_path_with_fanout(l->key_sha1, fanout, | |
513 | path); | |
514 | /* Create trailing slash, if needed */ | |
515 | if (path[path_len - 1] != '/') | |
516 | path[path_len++] = '/'; | |
517 | path[path_len] = '\0'; | |
518 | ret = fn(l->key_sha1, l->val_sha1, path, | |
519 | cb_data); | |
520 | } | |
521 | if (n > fanout * 2 || | |
522 | !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) { | |
523 | /* unpack subtree and resume traversal */ | |
524 | tree->a[i] = NULL; | |
525 | load_subtree(l, tree, n); | |
526 | free(l); | |
527 | goto redo; | |
528 | } | |
529 | break; | |
530 | case PTR_TYPE_NOTE: | |
531 | l = (struct leaf_node *) CLR_PTR_TYPE(p); | |
532 | construct_path_with_fanout(l->key_sha1, fanout, path); | |
533 | ret = fn(l->key_sha1, l->val_sha1, path, cb_data); | |
534 | break; | |
535 | } | |
536 | if (ret) | |
537 | return ret; | |
538 | } | |
539 | return 0; | |
540 | } | |
541 | ||
61a7cca0 JH |
542 | struct tree_write_stack { |
543 | struct tree_write_stack *next; | |
544 | struct strbuf buf; | |
545 | char path[2]; /* path to subtree in next, if any */ | |
546 | }; | |
547 | ||
548 | static inline int matches_tree_write_stack(struct tree_write_stack *tws, | |
549 | const char *full_path) | |
550 | { | |
551 | return full_path[0] == tws->path[0] && | |
552 | full_path[1] == tws->path[1] && | |
553 | full_path[2] == '/'; | |
554 | } | |
555 | ||
556 | static void write_tree_entry(struct strbuf *buf, unsigned int mode, | |
557 | const char *path, unsigned int path_len, const | |
558 | unsigned char *sha1) | |
559 | { | |
560 | strbuf_addf(buf, "%06o %.*s%c", mode, path_len, path, '\0'); | |
561 | strbuf_add(buf, sha1, 20); | |
562 | } | |
563 | ||
564 | static void tree_write_stack_init_subtree(struct tree_write_stack *tws, | |
565 | const char *path) | |
566 | { | |
567 | struct tree_write_stack *n; | |
568 | assert(!tws->next); | |
569 | assert(tws->path[0] == '\0' && tws->path[1] == '\0'); | |
570 | n = (struct tree_write_stack *) | |
571 | xmalloc(sizeof(struct tree_write_stack)); | |
572 | n->next = NULL; | |
573 | strbuf_init(&n->buf, 256 * (32 + 40)); /* assume 256 entries per tree */ | |
574 | n->path[0] = n->path[1] = '\0'; | |
575 | tws->next = n; | |
576 | tws->path[0] = path[0]; | |
577 | tws->path[1] = path[1]; | |
578 | } | |
579 | ||
580 | static int tree_write_stack_finish_subtree(struct tree_write_stack *tws) | |
581 | { | |
582 | int ret; | |
583 | struct tree_write_stack *n = tws->next; | |
584 | unsigned char s[20]; | |
585 | if (n) { | |
586 | ret = tree_write_stack_finish_subtree(n); | |
587 | if (ret) | |
588 | return ret; | |
589 | ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s); | |
590 | if (ret) | |
591 | return ret; | |
592 | strbuf_release(&n->buf); | |
593 | free(n); | |
594 | tws->next = NULL; | |
595 | write_tree_entry(&tws->buf, 040000, tws->path, 2, s); | |
596 | tws->path[0] = tws->path[1] = '\0'; | |
597 | } | |
598 | return 0; | |
599 | } | |
600 | ||
601 | static int write_each_note_helper(struct tree_write_stack *tws, | |
602 | const char *path, unsigned int mode, | |
603 | const unsigned char *sha1) | |
604 | { | |
605 | size_t path_len = strlen(path); | |
606 | unsigned int n = 0; | |
607 | int ret; | |
608 | ||
609 | /* Determine common part of tree write stack */ | |
610 | while (tws && 3 * n < path_len && | |
611 | matches_tree_write_stack(tws, path + 3 * n)) { | |
612 | n++; | |
613 | tws = tws->next; | |
614 | } | |
615 | ||
616 | /* tws point to last matching tree_write_stack entry */ | |
617 | ret = tree_write_stack_finish_subtree(tws); | |
618 | if (ret) | |
619 | return ret; | |
620 | ||
621 | /* Start subtrees needed to satisfy path */ | |
622 | while (3 * n + 2 < path_len && path[3 * n + 2] == '/') { | |
623 | tree_write_stack_init_subtree(tws, path + 3 * n); | |
624 | n++; | |
625 | tws = tws->next; | |
626 | } | |
627 | ||
628 | /* There should be no more directory components in the given path */ | |
629 | assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL); | |
630 | ||
631 | /* Finally add given entry to the current tree object */ | |
632 | write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n), | |
633 | sha1); | |
634 | ||
635 | return 0; | |
636 | } | |
637 | ||
638 | struct write_each_note_data { | |
639 | struct tree_write_stack *root; | |
640 | }; | |
641 | ||
642 | static int write_each_note(const unsigned char *object_sha1, | |
643 | const unsigned char *note_sha1, char *note_path, | |
644 | void *cb_data) | |
645 | { | |
646 | struct write_each_note_data *d = | |
647 | (struct write_each_note_data *) cb_data; | |
648 | size_t note_path_len = strlen(note_path); | |
649 | unsigned int mode = 0100644; | |
650 | ||
651 | if (note_path[note_path_len - 1] == '/') { | |
652 | /* subtree entry */ | |
653 | note_path_len--; | |
654 | note_path[note_path_len] = '\0'; | |
655 | mode = 040000; | |
656 | } | |
657 | assert(note_path_len <= 40 + 19); | |
658 | ||
659 | return write_each_note_helper(d->root, note_path, mode, note_sha1); | |
660 | } | |
661 | ||
cd305392 | 662 | void init_notes(struct notes_tree *t, const char *notes_ref, int flags) |
23123aec | 663 | { |
a7e7eff6 | 664 | unsigned char sha1[20], object_sha1[20]; |
23123aec JH |
665 | unsigned mode; |
666 | struct leaf_node root_tree; | |
fd53c9eb | 667 | |
cd305392 JH |
668 | if (!t) |
669 | t = &default_notes_tree; | |
670 | assert(!t->initialized); | |
709f79b0 JH |
671 | |
672 | if (!notes_ref) | |
673 | notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT); | |
674 | if (!notes_ref) | |
675 | notes_ref = notes_ref_name; /* value of core.notesRef config */ | |
676 | if (!notes_ref) | |
677 | notes_ref = GIT_NOTES_DEFAULT_REF; | |
678 | ||
cd305392 JH |
679 | t->root = (struct int_node *) xcalloc(sizeof(struct int_node), 1); |
680 | t->ref = notes_ref ? xstrdup(notes_ref) : NULL; | |
681 | t->initialized = 1; | |
682 | ||
709f79b0 JH |
683 | if (flags & NOTES_INIT_EMPTY || !notes_ref || |
684 | read_ref(notes_ref, object_sha1)) | |
fd53c9eb | 685 | return; |
709f79b0 JH |
686 | if (get_tree_entry(object_sha1, "", sha1, &mode)) |
687 | die("Failed to read notes tree referenced by %s (%s)", | |
688 | notes_ref, object_sha1); | |
fd53c9eb | 689 | |
23123aec JH |
690 | hashclr(root_tree.key_sha1); |
691 | hashcpy(root_tree.val_sha1, sha1); | |
cd305392 | 692 | load_subtree(&root_tree, t->root, 0); |
fd53c9eb JS |
693 | } |
694 | ||
cd305392 JH |
695 | void add_note(struct notes_tree *t, const unsigned char *object_sha1, |
696 | const unsigned char *note_sha1) | |
2626b536 JH |
697 | { |
698 | struct leaf_node *l; | |
699 | ||
cd305392 JH |
700 | if (!t) |
701 | t = &default_notes_tree; | |
702 | assert(t->initialized); | |
2626b536 JH |
703 | l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node)); |
704 | hashcpy(l->key_sha1, object_sha1); | |
705 | hashcpy(l->val_sha1, note_sha1); | |
cd305392 | 706 | note_tree_insert(t->root, 0, l, PTR_TYPE_NOTE); |
2626b536 JH |
707 | } |
708 | ||
cd305392 | 709 | void remove_note(struct notes_tree *t, const unsigned char *object_sha1) |
1ec666b0 JH |
710 | { |
711 | struct leaf_node l; | |
712 | ||
cd305392 JH |
713 | if (!t) |
714 | t = &default_notes_tree; | |
715 | assert(t->initialized); | |
1ec666b0 JH |
716 | hashcpy(l.key_sha1, object_sha1); |
717 | hashclr(l.val_sha1); | |
cd305392 | 718 | return note_tree_remove(t, t->root, 0, &l); |
1ec666b0 JH |
719 | } |
720 | ||
cd305392 JH |
721 | const unsigned char *get_note(struct notes_tree *t, |
722 | const unsigned char *object_sha1) | |
fd53c9eb | 723 | { |
9b391f21 JH |
724 | struct leaf_node *found; |
725 | ||
cd305392 JH |
726 | if (!t) |
727 | t = &default_notes_tree; | |
728 | assert(t->initialized); | |
729 | found = note_tree_find(t->root, 0, object_sha1); | |
9b391f21 | 730 | return found ? found->val_sha1 : NULL; |
fd53c9eb | 731 | } |
a97a7468 | 732 | |
cd305392 JH |
733 | int for_each_note(struct notes_tree *t, int flags, each_note_fn fn, |
734 | void *cb_data) | |
73f77b90 | 735 | { |
cd305392 JH |
736 | if (!t) |
737 | t = &default_notes_tree; | |
738 | assert(t->initialized); | |
739 | return for_each_note_helper(t->root, 0, 0, flags, fn, cb_data); | |
73f77b90 JH |
740 | } |
741 | ||
cd305392 | 742 | int write_notes_tree(struct notes_tree *t, unsigned char *result) |
61a7cca0 JH |
743 | { |
744 | struct tree_write_stack root; | |
745 | struct write_each_note_data cb_data; | |
746 | int ret; | |
747 | ||
cd305392 JH |
748 | if (!t) |
749 | t = &default_notes_tree; | |
750 | assert(t->initialized); | |
61a7cca0 JH |
751 | |
752 | /* Prepare for traversal of current notes tree */ | |
753 | root.next = NULL; /* last forward entry in list is grounded */ | |
754 | strbuf_init(&root.buf, 256 * (32 + 40)); /* assume 256 entries */ | |
755 | root.path[0] = root.path[1] = '\0'; | |
756 | cb_data.root = &root; | |
757 | ||
758 | /* Write tree objects representing current notes tree */ | |
cd305392 | 759 | ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES | |
61a7cca0 JH |
760 | FOR_EACH_NOTE_YIELD_SUBTREES, |
761 | write_each_note, &cb_data) || | |
762 | tree_write_stack_finish_subtree(&root) || | |
763 | write_sha1_file(root.buf.buf, root.buf.len, tree_type, result); | |
764 | strbuf_release(&root.buf); | |
765 | return ret; | |
766 | } | |
767 | ||
cd305392 | 768 | void free_notes(struct notes_tree *t) |
27d57564 | 769 | { |
cd305392 JH |
770 | if (!t) |
771 | t = &default_notes_tree; | |
772 | if (t->root) | |
773 | note_tree_free(t->root); | |
774 | free(t->root); | |
775 | free(t->ref); | |
776 | memset(t, 0, sizeof(struct notes_tree)); | |
27d57564 JH |
777 | } |
778 | ||
cd305392 JH |
779 | void format_note(struct notes_tree *t, const unsigned char *object_sha1, |
780 | struct strbuf *sb, const char *output_encoding, int flags) | |
a97a7468 JS |
781 | { |
782 | static const char utf8[] = "utf-8"; | |
9b391f21 | 783 | const unsigned char *sha1; |
a97a7468 JS |
784 | char *msg, *msg_p; |
785 | unsigned long linelen, msglen; | |
786 | enum object_type type; | |
787 | ||
cd305392 JH |
788 | if (!t) |
789 | t = &default_notes_tree; | |
790 | if (!t->initialized) | |
791 | init_notes(t, NULL, 0); | |
a97a7468 | 792 | |
cd305392 | 793 | sha1 = get_note(t, object_sha1); |
fd53c9eb | 794 | if (!sha1) |
a97a7468 JS |
795 | return; |
796 | ||
797 | if (!(msg = read_sha1_file(sha1, &type, &msglen)) || !msglen || | |
798 | type != OBJ_BLOB) { | |
799 | free(msg); | |
800 | return; | |
801 | } | |
802 | ||
803 | if (output_encoding && *output_encoding && | |
804 | strcmp(utf8, output_encoding)) { | |
805 | char *reencoded = reencode_string(msg, output_encoding, utf8); | |
806 | if (reencoded) { | |
807 | free(msg); | |
808 | msg = reencoded; | |
809 | msglen = strlen(msg); | |
810 | } | |
811 | } | |
812 | ||
813 | /* we will end the annotation by a newline anyway */ | |
814 | if (msglen && msg[msglen - 1] == '\n') | |
815 | msglen--; | |
816 | ||
c56fcc89 JH |
817 | if (flags & NOTES_SHOW_HEADER) |
818 | strbuf_addstr(sb, "\nNotes:\n"); | |
a97a7468 JS |
819 | |
820 | for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) { | |
821 | linelen = strchrnul(msg_p, '\n') - msg_p; | |
822 | ||
c56fcc89 JH |
823 | if (flags & NOTES_INDENT) |
824 | strbuf_addstr(sb, " "); | |
a97a7468 JS |
825 | strbuf_add(sb, msg_p, linelen); |
826 | strbuf_addch(sb, '\n'); | |
827 | } | |
828 | ||
829 | free(msg); | |
830 | } |