t3305: Verify that adding many notes with git-notes triggers increased fanout
[git/git.git] / notes.c
CommitLineData
a97a7468 1#include "cache.h"
a97a7468 2#include "notes.h"
73f464b5 3#include "blob.h"
61a7cca0 4#include "tree.h"
a97a7468
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5#include "utf8.h"
6#include "strbuf.h"
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JS
7#include "tree-walk.h"
8
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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 */
21struct int_node {
22 void *a[16];
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JS
23};
24
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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
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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
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32 * the prefix. The value is the SHA1 of the tree object containing the notes
33 * subtree.
34 */
35struct leaf_node {
36 unsigned char key_sha1[20];
37 unsigned char val_sha1[20];
fd53c9eb 38};
a97a7468 39
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40#define PTR_TYPE_NULL 0
41#define PTR_TYPE_INTERNAL 1
42#define PTR_TYPE_NOTE 2
43#define PTR_TYPE_SUBTREE 3
fd53c9eb 44
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45#define GET_PTR_TYPE(ptr) ((uintptr_t) (ptr) & 3)
46#define CLR_PTR_TYPE(ptr) ((void *) ((uintptr_t) (ptr) & ~3))
47#define SET_PTR_TYPE(ptr, type) ((void *) ((uintptr_t) (ptr) | (type)))
fd53c9eb 48
1ec666b0 49#define GET_NIBBLE(n, sha1) (((sha1[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f)
fd53c9eb 50
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51#define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
52 (memcmp(key_sha1, subtree_sha1, subtree_sha1[19]))
fd53c9eb 53
cd305392 54struct notes_tree default_notes_tree;
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55
56static void load_subtree(struct leaf_node *subtree, struct int_node *node,
57 unsigned int n);
58
59/*
ef8db638 60 * Search the tree until the appropriate location for the given key is found:
23123aec 61 * 1. Start at the root node, with n = 0
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62 * 2. If a[0] at the current level is a matching subtree entry, unpack that
63 * subtree entry and remove it; restart search at the current level.
64 * 3. Use the nth nibble of the key as an index into a:
65 * - If a[n] is an int_node, recurse from #2 into that node and increment n
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66 * - If a matching subtree entry, unpack that subtree entry (and remove it);
67 * restart search at the current level.
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68 * - Otherwise, we have found one of the following:
69 * - a subtree entry which does not match the key
70 * - a note entry which may or may not match the key
71 * - an unused leaf node (NULL)
72 * In any case, set *tree and *n, and return pointer to the tree location.
23123aec 73 */
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74static void **note_tree_search(struct int_node **tree,
75 unsigned char *n, const unsigned char *key_sha1)
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76{
77 struct leaf_node *l;
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78 unsigned char i;
79 void *p = (*tree)->a[0];
23123aec 80
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81 if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) {
82 l = (struct leaf_node *) CLR_PTR_TYPE(p);
83 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
84 /* unpack tree and resume search */
85 (*tree)->a[0] = NULL;
86 load_subtree(l, *tree, *n);
87 free(l);
88 return note_tree_search(tree, n, key_sha1);
89 }
90 }
91
92 i = GET_NIBBLE(*n, key_sha1);
93 p = (*tree)->a[i];
0ab1faae 94 switch (GET_PTR_TYPE(p)) {
23123aec 95 case PTR_TYPE_INTERNAL:
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96 *tree = CLR_PTR_TYPE(p);
97 (*n)++;
98 return note_tree_search(tree, n, key_sha1);
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99 case PTR_TYPE_SUBTREE:
100 l = (struct leaf_node *) CLR_PTR_TYPE(p);
101 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
102 /* unpack tree and resume search */
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JH
103 (*tree)->a[i] = NULL;
104 load_subtree(l, *tree, *n);
23123aec 105 free(l);
ef8db638 106 return note_tree_search(tree, n, key_sha1);
23123aec 107 }
ef8db638 108 /* fall through */
23123aec 109 default:
ef8db638 110 return &((*tree)->a[i]);
fd53c9eb 111 }
ef8db638 112}
23123aec 113
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114/*
115 * To find a leaf_node:
116 * Search to the tree location appropriate for the given key:
117 * If a note entry with matching key, return the note entry, else return NULL.
118 */
119static struct leaf_node *note_tree_find(struct int_node *tree, unsigned char n,
120 const unsigned char *key_sha1)
121{
122 void **p = note_tree_search(&tree, &n, key_sha1);
123 if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) {
124 struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p);
125 if (!hashcmp(key_sha1, l->key_sha1))
126 return l;
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127 }
128 return NULL;
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129}
130
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131/*
132 * To insert a leaf_node:
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133 * Search to the tree location appropriate for the given leaf_node's key:
134 * - If location is unused (NULL), store the tweaked pointer directly there
135 * - If location holds a note entry that matches the note-to-be-inserted, then
73f464b5 136 * combine the two notes (by calling the given combine_notes function).
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137 * - If location holds a note entry that matches the subtree-to-be-inserted,
138 * then unpack the subtree-to-be-inserted into the location.
139 * - If location holds a matching subtree entry, unpack the subtree at that
140 * location, and restart the insert operation from that level.
141 * - Else, create a new int_node, holding both the node-at-location and the
142 * node-to-be-inserted, and store the new int_node into the location.
23123aec 143 */
ef8db638 144static void note_tree_insert(struct int_node *tree, unsigned char n,
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145 struct leaf_node *entry, unsigned char type,
146 combine_notes_fn combine_notes)
fd53c9eb 147{
23123aec 148 struct int_node *new_node;
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149 struct leaf_node *l;
150 void **p = note_tree_search(&tree, &n, entry->key_sha1);
151
152 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
153 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
0ab1faae 154 switch (GET_PTR_TYPE(*p)) {
23123aec 155 case PTR_TYPE_NULL:
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156 assert(!*p);
157 *p = SET_PTR_TYPE(entry, type);
158 return;
159 case PTR_TYPE_NOTE:
160 switch (type) {
161 case PTR_TYPE_NOTE:
162 if (!hashcmp(l->key_sha1, entry->key_sha1)) {
163 /* skip concatenation if l == entry */
164 if (!hashcmp(l->val_sha1, entry->val_sha1))
165 return;
166
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167 if (combine_notes(l->val_sha1, entry->val_sha1))
168 die("failed to combine notes %s and %s"
169 " for object %s",
ef8db638 170 sha1_to_hex(l->val_sha1),
73f464b5 171 sha1_to_hex(entry->val_sha1),
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172 sha1_to_hex(l->key_sha1));
173 free(entry);
174 return;
175 }
176 break;
177 case PTR_TYPE_SUBTREE:
178 if (!SUBTREE_SHA1_PREFIXCMP(l->key_sha1,
179 entry->key_sha1)) {
180 /* unpack 'entry' */
181 load_subtree(entry, tree, n);
182 free(entry);
183 return;
184 }
185 break;
186 }
187 break;
188 case PTR_TYPE_SUBTREE:
189 if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) {
190 /* unpack 'l' and restart insert */
191 *p = NULL;
192 load_subtree(l, tree, n);
193 free(l);
73f464b5 194 note_tree_insert(tree, n, entry, type, combine_notes);
ef8db638 195 return;
23123aec 196 }
ef8db638 197 break;
fd53c9eb 198 }
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199
200 /* non-matching leaf_node */
201 assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
202 GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
203 new_node = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
73f464b5 204 note_tree_insert(new_node, n + 1, l, GET_PTR_TYPE(*p), combine_notes);
ef8db638 205 *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
73f464b5 206 note_tree_insert(new_node, n + 1, entry, type, combine_notes);
23123aec 207}
fd53c9eb 208
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209/*
210 * How to consolidate an int_node:
211 * If there are > 1 non-NULL entries, give up and return non-zero.
212 * Otherwise replace the int_node at the given index in the given parent node
213 * with the only entry (or a NULL entry if no entries) from the given tree,
214 * and return 0.
215 */
216static int note_tree_consolidate(struct int_node *tree,
217 struct int_node *parent, unsigned char index)
218{
219 unsigned int i;
220 void *p = NULL;
221
222 assert(tree && parent);
223 assert(CLR_PTR_TYPE(parent->a[index]) == tree);
224
225 for (i = 0; i < 16; i++) {
226 if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) {
227 if (p) /* more than one entry */
228 return -2;
229 p = tree->a[i];
230 }
231 }
232
233 /* replace tree with p in parent[index] */
234 parent->a[index] = p;
235 free(tree);
236 return 0;
237}
238
239/*
240 * To remove a leaf_node:
241 * Search to the tree location appropriate for the given leaf_node's key:
242 * - If location does not hold a matching entry, abort and do nothing.
243 * - Replace the matching leaf_node with a NULL entry (and free the leaf_node).
244 * - Consolidate int_nodes repeatedly, while walking up the tree towards root.
245 */
cd305392
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246static void note_tree_remove(struct notes_tree *t, struct int_node *tree,
247 unsigned char n, struct leaf_node *entry)
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248{
249 struct leaf_node *l;
250 struct int_node *parent_stack[20];
251 unsigned char i, j;
252 void **p = note_tree_search(&tree, &n, entry->key_sha1);
253
254 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
255 if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
256 return; /* type mismatch, nothing to remove */
257 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
258 if (hashcmp(l->key_sha1, entry->key_sha1))
259 return; /* key mismatch, nothing to remove */
260
261 /* we have found a matching entry */
262 free(l);
263 *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
264
265 /* consolidate this tree level, and parent levels, if possible */
266 if (!n)
267 return; /* cannot consolidate top level */
268 /* first, build stack of ancestors between root and current node */
cd305392 269 parent_stack[0] = t->root;
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270 for (i = 0; i < n; i++) {
271 j = GET_NIBBLE(i, entry->key_sha1);
272 parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]);
273 }
274 assert(i == n && parent_stack[i] == tree);
275 /* next, unwind stack until note_tree_consolidate() is done */
276 while (i > 0 &&
277 !note_tree_consolidate(parent_stack[i], parent_stack[i - 1],
278 GET_NIBBLE(i - 1, entry->key_sha1)))
279 i--;
280}
281
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282/* Free the entire notes data contained in the given tree */
283static void note_tree_free(struct int_node *tree)
284{
285 unsigned int i;
286 for (i = 0; i < 16; i++) {
287 void *p = tree->a[i];
0ab1faae 288 switch (GET_PTR_TYPE(p)) {
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JH
289 case PTR_TYPE_INTERNAL:
290 note_tree_free(CLR_PTR_TYPE(p));
291 /* fall through */
292 case PTR_TYPE_NOTE:
293 case PTR_TYPE_SUBTREE:
294 free(CLR_PTR_TYPE(p));
295 }
fd53c9eb 296 }
23123aec 297}
fd53c9eb 298
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299/*
300 * Convert a partial SHA1 hex string to the corresponding partial SHA1 value.
301 * - hex - Partial SHA1 segment in ASCII hex format
302 * - hex_len - Length of above segment. Must be multiple of 2 between 0 and 40
303 * - sha1 - Partial SHA1 value is written here
304 * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20
0ab1faae 305 * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format)).
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306 * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2).
307 * Pads sha1 with NULs up to sha1_len (not included in returned length).
308 */
309static int get_sha1_hex_segment(const char *hex, unsigned int hex_len,
310 unsigned char *sha1, unsigned int sha1_len)
311{
312 unsigned int i, len = hex_len >> 1;
313 if (hex_len % 2 != 0 || len > sha1_len)
314 return -1;
315 for (i = 0; i < len; i++) {
316 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
317 if (val & ~0xff)
318 return -1;
319 *sha1++ = val;
320 hex += 2;
321 }
322 for (; i < sha1_len; i++)
323 *sha1++ = 0;
324 return len;
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325}
326
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327static void load_subtree(struct leaf_node *subtree, struct int_node *node,
328 unsigned int n)
fd53c9eb 329{
a7e7eff6 330 unsigned char object_sha1[20];
23123aec 331 unsigned int prefix_len;
23123aec 332 void *buf;
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JS
333 struct tree_desc desc;
334 struct name_entry entry;
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JH
335
336 buf = fill_tree_descriptor(&desc, subtree->val_sha1);
337 if (!buf)
338 die("Could not read %s for notes-index",
339 sha1_to_hex(subtree->val_sha1));
340
341 prefix_len = subtree->key_sha1[19];
342 assert(prefix_len * 2 >= n);
a7e7eff6 343 memcpy(object_sha1, subtree->key_sha1, prefix_len);
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344 while (tree_entry(&desc, &entry)) {
345 int len = get_sha1_hex_segment(entry.path, strlen(entry.path),
a7e7eff6 346 object_sha1 + prefix_len, 20 - prefix_len);
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347 if (len < 0)
348 continue; /* entry.path is not a SHA1 sum. Skip */
349 len += prefix_len;
350
351 /*
a7e7eff6
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352 * If object SHA1 is complete (len == 20), assume note object
353 * If object SHA1 is incomplete (len < 20), assume note subtree
23123aec
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354 */
355 if (len <= 20) {
356 unsigned char type = PTR_TYPE_NOTE;
357 struct leaf_node *l = (struct leaf_node *)
358 xcalloc(sizeof(struct leaf_node), 1);
a7e7eff6 359 hashcpy(l->key_sha1, object_sha1);
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360 hashcpy(l->val_sha1, entry.sha1);
361 if (len < 20) {
488bdf2e
JH
362 if (!S_ISDIR(entry.mode))
363 continue; /* entry cannot be subtree */
23123aec
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364 l->key_sha1[19] = (unsigned char) len;
365 type = PTR_TYPE_SUBTREE;
366 }
73f464b5
JH
367 note_tree_insert(node, n, l, type,
368 combine_notes_concatenate);
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369 }
370 }
371 free(buf);
372}
373
73f77b90
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374/*
375 * Determine optimal on-disk fanout for this part of the notes tree
376 *
377 * Given a (sub)tree and the level in the internal tree structure, determine
378 * whether or not the given existing fanout should be expanded for this
379 * (sub)tree.
380 *
381 * Values of the 'fanout' variable:
382 * - 0: No fanout (all notes are stored directly in the root notes tree)
383 * - 1: 2/38 fanout
384 * - 2: 2/2/36 fanout
385 * - 3: 2/2/2/34 fanout
386 * etc.
387 */
388static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
389 unsigned char fanout)
390{
391 /*
392 * The following is a simple heuristic that works well in practice:
393 * For each even-numbered 16-tree level (remember that each on-disk
394 * fanout level corresponds to _two_ 16-tree levels), peek at all 16
395 * entries at that tree level. If all of them are either int_nodes or
396 * subtree entries, then there are likely plenty of notes below this
397 * level, so we return an incremented fanout.
398 */
399 unsigned int i;
400 if ((n % 2) || (n > 2 * fanout))
401 return fanout;
402 for (i = 0; i < 16; i++) {
403 switch (GET_PTR_TYPE(tree->a[i])) {
404 case PTR_TYPE_SUBTREE:
405 case PTR_TYPE_INTERNAL:
406 continue;
407 default:
408 return fanout;
409 }
410 }
411 return fanout + 1;
412}
413
414static void construct_path_with_fanout(const unsigned char *sha1,
415 unsigned char fanout, char *path)
416{
417 unsigned int i = 0, j = 0;
418 const char *hex_sha1 = sha1_to_hex(sha1);
419 assert(fanout < 20);
420 while (fanout) {
421 path[i++] = hex_sha1[j++];
422 path[i++] = hex_sha1[j++];
423 path[i++] = '/';
424 fanout--;
425 }
426 strcpy(path + i, hex_sha1 + j);
427}
428
429static int for_each_note_helper(struct int_node *tree, unsigned char n,
430 unsigned char fanout, int flags, each_note_fn fn,
431 void *cb_data)
432{
433 unsigned int i;
434 void *p;
435 int ret = 0;
436 struct leaf_node *l;
437 static char path[40 + 19 + 1]; /* hex SHA1 + 19 * '/' + NUL */
438
439 fanout = determine_fanout(tree, n, fanout);
440 for (i = 0; i < 16; i++) {
441redo:
442 p = tree->a[i];
443 switch (GET_PTR_TYPE(p)) {
444 case PTR_TYPE_INTERNAL:
445 /* recurse into int_node */
446 ret = for_each_note_helper(CLR_PTR_TYPE(p), n + 1,
447 fanout, flags, fn, cb_data);
448 break;
449 case PTR_TYPE_SUBTREE:
450 l = (struct leaf_node *) CLR_PTR_TYPE(p);
451 /*
452 * Subtree entries in the note tree represent parts of
453 * the note tree that have not yet been explored. There
454 * is a direct relationship between subtree entries at
455 * level 'n' in the tree, and the 'fanout' variable:
456 * Subtree entries at level 'n <= 2 * fanout' should be
457 * preserved, since they correspond exactly to a fanout
458 * directory in the on-disk structure. However, subtree
459 * entries at level 'n > 2 * fanout' should NOT be
460 * preserved, but rather consolidated into the above
461 * notes tree level. We achieve this by unconditionally
462 * unpacking subtree entries that exist below the
463 * threshold level at 'n = 2 * fanout'.
464 */
465 if (n <= 2 * fanout &&
466 flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
467 /* invoke callback with subtree */
468 unsigned int path_len =
469 l->key_sha1[19] * 2 + fanout;
470 assert(path_len < 40 + 19);
471 construct_path_with_fanout(l->key_sha1, fanout,
472 path);
473 /* Create trailing slash, if needed */
474 if (path[path_len - 1] != '/')
475 path[path_len++] = '/';
476 path[path_len] = '\0';
477 ret = fn(l->key_sha1, l->val_sha1, path,
478 cb_data);
479 }
480 if (n > fanout * 2 ||
481 !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
482 /* unpack subtree and resume traversal */
483 tree->a[i] = NULL;
484 load_subtree(l, tree, n);
485 free(l);
486 goto redo;
487 }
488 break;
489 case PTR_TYPE_NOTE:
490 l = (struct leaf_node *) CLR_PTR_TYPE(p);
491 construct_path_with_fanout(l->key_sha1, fanout, path);
492 ret = fn(l->key_sha1, l->val_sha1, path, cb_data);
493 break;
494 }
495 if (ret)
496 return ret;
497 }
498 return 0;
499}
500
61a7cca0
JH
501struct tree_write_stack {
502 struct tree_write_stack *next;
503 struct strbuf buf;
504 char path[2]; /* path to subtree in next, if any */
505};
506
507static inline int matches_tree_write_stack(struct tree_write_stack *tws,
508 const char *full_path)
509{
510 return full_path[0] == tws->path[0] &&
511 full_path[1] == tws->path[1] &&
512 full_path[2] == '/';
513}
514
515static void write_tree_entry(struct strbuf *buf, unsigned int mode,
516 const char *path, unsigned int path_len, const
517 unsigned char *sha1)
518{
519 strbuf_addf(buf, "%06o %.*s%c", mode, path_len, path, '\0');
520 strbuf_add(buf, sha1, 20);
521}
522
523static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
524 const char *path)
525{
526 struct tree_write_stack *n;
527 assert(!tws->next);
528 assert(tws->path[0] == '\0' && tws->path[1] == '\0');
529 n = (struct tree_write_stack *)
530 xmalloc(sizeof(struct tree_write_stack));
531 n->next = NULL;
532 strbuf_init(&n->buf, 256 * (32 + 40)); /* assume 256 entries per tree */
533 n->path[0] = n->path[1] = '\0';
534 tws->next = n;
535 tws->path[0] = path[0];
536 tws->path[1] = path[1];
537}
538
539static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
540{
541 int ret;
542 struct tree_write_stack *n = tws->next;
543 unsigned char s[20];
544 if (n) {
545 ret = tree_write_stack_finish_subtree(n);
546 if (ret)
547 return ret;
548 ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s);
549 if (ret)
550 return ret;
551 strbuf_release(&n->buf);
552 free(n);
553 tws->next = NULL;
554 write_tree_entry(&tws->buf, 040000, tws->path, 2, s);
555 tws->path[0] = tws->path[1] = '\0';
556 }
557 return 0;
558}
559
560static int write_each_note_helper(struct tree_write_stack *tws,
561 const char *path, unsigned int mode,
562 const unsigned char *sha1)
563{
564 size_t path_len = strlen(path);
565 unsigned int n = 0;
566 int ret;
567
568 /* Determine common part of tree write stack */
569 while (tws && 3 * n < path_len &&
570 matches_tree_write_stack(tws, path + 3 * n)) {
571 n++;
572 tws = tws->next;
573 }
574
575 /* tws point to last matching tree_write_stack entry */
576 ret = tree_write_stack_finish_subtree(tws);
577 if (ret)
578 return ret;
579
580 /* Start subtrees needed to satisfy path */
581 while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
582 tree_write_stack_init_subtree(tws, path + 3 * n);
583 n++;
584 tws = tws->next;
585 }
586
587 /* There should be no more directory components in the given path */
588 assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
589
590 /* Finally add given entry to the current tree object */
591 write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
592 sha1);
593
594 return 0;
595}
596
597struct write_each_note_data {
598 struct tree_write_stack *root;
599};
600
601static int write_each_note(const unsigned char *object_sha1,
602 const unsigned char *note_sha1, char *note_path,
603 void *cb_data)
604{
605 struct write_each_note_data *d =
606 (struct write_each_note_data *) cb_data;
607 size_t note_path_len = strlen(note_path);
608 unsigned int mode = 0100644;
609
610 if (note_path[note_path_len - 1] == '/') {
611 /* subtree entry */
612 note_path_len--;
613 note_path[note_path_len] = '\0';
614 mode = 040000;
615 }
616 assert(note_path_len <= 40 + 19);
617
618 return write_each_note_helper(d->root, note_path, mode, note_sha1);
619}
620
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621int combine_notes_concatenate(unsigned char *cur_sha1,
622 const unsigned char *new_sha1)
623{
624 char *cur_msg = NULL, *new_msg = NULL, *buf;
625 unsigned long cur_len, new_len, buf_len;
626 enum object_type cur_type, new_type;
627 int ret;
628
629 /* read in both note blob objects */
630 if (!is_null_sha1(new_sha1))
631 new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
632 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
633 free(new_msg);
634 return 0;
635 }
636 if (!is_null_sha1(cur_sha1))
637 cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
638 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
639 free(cur_msg);
640 free(new_msg);
641 hashcpy(cur_sha1, new_sha1);
642 return 0;
643 }
644
645 /* we will separate the notes by a newline anyway */
646 if (cur_msg[cur_len - 1] == '\n')
647 cur_len--;
648
649 /* concatenate cur_msg and new_msg into buf */
650 buf_len = cur_len + 1 + new_len;
651 buf = (char *) xmalloc(buf_len);
652 memcpy(buf, cur_msg, cur_len);
653 buf[cur_len] = '\n';
654 memcpy(buf + cur_len + 1, new_msg, new_len);
655 free(cur_msg);
656 free(new_msg);
657
658 /* create a new blob object from buf */
659 ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
660 free(buf);
661 return ret;
662}
663
664int combine_notes_overwrite(unsigned char *cur_sha1,
665 const unsigned char *new_sha1)
666{
667 hashcpy(cur_sha1, new_sha1);
668 return 0;
669}
670
671int combine_notes_ignore(unsigned char *cur_sha1,
672 const unsigned char *new_sha1)
673{
674 return 0;
675}
676
677void init_notes(struct notes_tree *t, const char *notes_ref,
678 combine_notes_fn combine_notes, int flags)
23123aec 679{
a7e7eff6 680 unsigned char sha1[20], object_sha1[20];
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681 unsigned mode;
682 struct leaf_node root_tree;
fd53c9eb 683
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684 if (!t)
685 t = &default_notes_tree;
686 assert(!t->initialized);
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687
688 if (!notes_ref)
689 notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
690 if (!notes_ref)
691 notes_ref = notes_ref_name; /* value of core.notesRef config */
692 if (!notes_ref)
693 notes_ref = GIT_NOTES_DEFAULT_REF;
694
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695 if (!combine_notes)
696 combine_notes = combine_notes_concatenate;
697
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698 t->root = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
699 t->ref = notes_ref ? xstrdup(notes_ref) : NULL;
73f464b5 700 t->combine_notes = combine_notes;
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701 t->initialized = 1;
702
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703 if (flags & NOTES_INIT_EMPTY || !notes_ref ||
704 read_ref(notes_ref, object_sha1))
fd53c9eb 705 return;
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706 if (get_tree_entry(object_sha1, "", sha1, &mode))
707 die("Failed to read notes tree referenced by %s (%s)",
708 notes_ref, object_sha1);
fd53c9eb 709
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710 hashclr(root_tree.key_sha1);
711 hashcpy(root_tree.val_sha1, sha1);
cd305392 712 load_subtree(&root_tree, t->root, 0);
fd53c9eb
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713}
714
cd305392 715void add_note(struct notes_tree *t, const unsigned char *object_sha1,
73f464b5 716 const unsigned char *note_sha1, combine_notes_fn combine_notes)
2626b536
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717{
718 struct leaf_node *l;
719
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720 if (!t)
721 t = &default_notes_tree;
722 assert(t->initialized);
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723 if (!combine_notes)
724 combine_notes = t->combine_notes;
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725 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
726 hashcpy(l->key_sha1, object_sha1);
727 hashcpy(l->val_sha1, note_sha1);
73f464b5 728 note_tree_insert(t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
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729}
730
cd305392 731void remove_note(struct notes_tree *t, const unsigned char *object_sha1)
1ec666b0
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732{
733 struct leaf_node l;
734
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735 if (!t)
736 t = &default_notes_tree;
737 assert(t->initialized);
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738 hashcpy(l.key_sha1, object_sha1);
739 hashclr(l.val_sha1);
cd305392 740 return note_tree_remove(t, t->root, 0, &l);
1ec666b0
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741}
742
cd305392
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743const unsigned char *get_note(struct notes_tree *t,
744 const unsigned char *object_sha1)
fd53c9eb 745{
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746 struct leaf_node *found;
747
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748 if (!t)
749 t = &default_notes_tree;
750 assert(t->initialized);
751 found = note_tree_find(t->root, 0, object_sha1);
9b391f21 752 return found ? found->val_sha1 : NULL;
fd53c9eb 753}
a97a7468 754
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755int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
756 void *cb_data)
73f77b90 757{
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758 if (!t)
759 t = &default_notes_tree;
760 assert(t->initialized);
761 return for_each_note_helper(t->root, 0, 0, flags, fn, cb_data);
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762}
763
cd305392 764int write_notes_tree(struct notes_tree *t, unsigned char *result)
61a7cca0
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765{
766 struct tree_write_stack root;
767 struct write_each_note_data cb_data;
768 int ret;
769
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770 if (!t)
771 t = &default_notes_tree;
772 assert(t->initialized);
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773
774 /* Prepare for traversal of current notes tree */
775 root.next = NULL; /* last forward entry in list is grounded */
776 strbuf_init(&root.buf, 256 * (32 + 40)); /* assume 256 entries */
777 root.path[0] = root.path[1] = '\0';
778 cb_data.root = &root;
779
780 /* Write tree objects representing current notes tree */
cd305392 781 ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
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782 FOR_EACH_NOTE_YIELD_SUBTREES,
783 write_each_note, &cb_data) ||
784 tree_write_stack_finish_subtree(&root) ||
785 write_sha1_file(root.buf.buf, root.buf.len, tree_type, result);
786 strbuf_release(&root.buf);
787 return ret;
788}
789
cd305392 790void free_notes(struct notes_tree *t)
27d57564 791{
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792 if (!t)
793 t = &default_notes_tree;
794 if (t->root)
795 note_tree_free(t->root);
796 free(t->root);
797 free(t->ref);
798 memset(t, 0, sizeof(struct notes_tree));
27d57564
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799}
800
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801void format_note(struct notes_tree *t, const unsigned char *object_sha1,
802 struct strbuf *sb, const char *output_encoding, int flags)
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803{
804 static const char utf8[] = "utf-8";
9b391f21 805 const unsigned char *sha1;
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806 char *msg, *msg_p;
807 unsigned long linelen, msglen;
808 enum object_type type;
809
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810 if (!t)
811 t = &default_notes_tree;
812 if (!t->initialized)
73f464b5 813 init_notes(t, NULL, NULL, 0);
a97a7468 814
cd305392 815 sha1 = get_note(t, object_sha1);
fd53c9eb 816 if (!sha1)
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817 return;
818
819 if (!(msg = read_sha1_file(sha1, &type, &msglen)) || !msglen ||
820 type != OBJ_BLOB) {
821 free(msg);
822 return;
823 }
824
825 if (output_encoding && *output_encoding &&
826 strcmp(utf8, output_encoding)) {
827 char *reencoded = reencode_string(msg, output_encoding, utf8);
828 if (reencoded) {
829 free(msg);
830 msg = reencoded;
831 msglen = strlen(msg);
832 }
833 }
834
835 /* we will end the annotation by a newline anyway */
836 if (msglen && msg[msglen - 1] == '\n')
837 msglen--;
838
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839 if (flags & NOTES_SHOW_HEADER)
840 strbuf_addstr(sb, "\nNotes:\n");
a97a7468
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841
842 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
843 linelen = strchrnul(msg_p, '\n') - msg_p;
844
c56fcc89
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845 if (flags & NOTES_INDENT)
846 strbuf_addstr(sb, " ");
a97a7468
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847 strbuf_add(sb, msg_p, linelen);
848 strbuf_addch(sb, '\n');
849 }
850
851 free(msg);
852}