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chromium / external / github.com / git / git / refs/tags/v1.7.0.3 / . / notes.c
blob: 023adce982c668f39b01652e525b54fd512d5603 [file] [log] [blame]
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]1#include "cache.h"
2#include "commit.h"
3#include "notes.h"
4#include "refs.h"
5#include "utf8.h"
6#include "strbuf.h"
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]7#include "tree-walk.h"
8
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]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];
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]23};
24
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]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).
28 * As a note entry, the key is the SHA1 of the referenced commit, and the
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
31 * referenced commit, using the last byte of the key to store the length of
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];
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]38};
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]39
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]40#define PTR_TYPE_NULL 0
41#define PTR_TYPE_INTERNAL 1
42#define PTR_TYPE_NOTE 2
43#define PTR_TYPE_SUBTREE 3
44
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)))
48
49#define GET_NIBBLE(n, sha1) (((sha1[n >> 1]) >> ((~n & 0x01) << 2)) & 0x0f)
50
51#define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
52 (memcmp(key_sha1, subtree_sha1, subtree_sha1[19]))
53
54static struct int_node root_node;
55
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]56static int initialized;
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]57
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]58static void load_subtree(struct leaf_node *subtree, struct int_node *node,
59 unsigned int n);
60
61/*
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]62 * Search the tree until the appropriate location for the given key is found:
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]63 * 1. Start at the root node, with n = 0
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]64 * 2. If a[0] at the current level is a matching subtree entry, unpack that
65 * subtree entry and remove it; restart search at the current level.
66 * 3. Use the nth nibble of the key as an index into a:
67 * - If a[n] is an int_node, recurse from #2 into that node and increment n
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]68 * - If a matching subtree entry, unpack that subtree entry (and remove it);
69 * restart search at the current level.
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]70 * - Otherwise, we have found one of the following:
71 * - a subtree entry which does not match the key
72 * - a note entry which may or may not match the key
73 * - an unused leaf node (NULL)
74 * In any case, set *tree and *n, and return pointer to the tree location.
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]75 */
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]76static void **note_tree_search(struct int_node **tree,
77 unsigned char *n, const unsigned char *key_sha1)
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]78{
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]79 struct leaf_node *l;
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]80 unsigned char i;
81 void *p = (*tree)->a[0];
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]82
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]83 if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) {
84 l = (struct leaf_node *) CLR_PTR_TYPE(p);
85 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
86 /* unpack tree and resume search */
87 (*tree)->a[0] = NULL;
88 load_subtree(l, *tree, *n);
89 free(l);
90 return note_tree_search(tree, n, key_sha1);
91 }
92 }
93
94 i = GET_NIBBLE(*n, key_sha1);
95 p = (*tree)->a[i];
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]96 switch(GET_PTR_TYPE(p)) {
97 case PTR_TYPE_INTERNAL:
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]98 *tree = CLR_PTR_TYPE(p);
99 (*n)++;
100 return note_tree_search(tree, n, key_sha1);
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]101 case PTR_TYPE_SUBTREE:
102 l = (struct leaf_node *) CLR_PTR_TYPE(p);
103 if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
104 /* unpack tree and resume search */
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]105 (*tree)->a[i] = NULL;
106 load_subtree(l, *tree, *n);
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]107 free(l);
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]108 return note_tree_search(tree, n, key_sha1);
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]109 }
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]110 /* fall through */
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]111 default:
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]112 return &((*tree)->a[i]);
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]113 }
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]114}
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]115
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]116/*
117 * To find a leaf_node:
118 * Search to the tree location appropriate for the given key:
119 * If a note entry with matching key, return the note entry, else return NULL.
120 */
121static struct leaf_node *note_tree_find(struct int_node *tree, unsigned char n,
122 const unsigned char *key_sha1)
123{
124 void **p = note_tree_search(&tree, &n, key_sha1);
125 if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) {
126 struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p);
127 if (!hashcmp(key_sha1, l->key_sha1))
128 return l;
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]129 }
130 return NULL;
131}
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]132
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]133/* Create a new blob object by concatenating the two given blob objects */
134static int concatenate_notes(unsigned char *cur_sha1,
135 const unsigned char *new_sha1)
136{
137 char *cur_msg, *new_msg, *buf;
138 unsigned long cur_len, new_len, buf_len;
139 enum object_type cur_type, new_type;
140 int ret;
141
142 /* read in both note blob objects */
143 new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
144 if (!new_msg || !new_len || new_type != OBJ_BLOB) {
145 free(new_msg);
146 return 0;
147 }
148 cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
149 if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
150 free(cur_msg);
151 free(new_msg);
152 hashcpy(cur_sha1, new_sha1);
153 return 0;
154 }
155
156 /* we will separate the notes by a newline anyway */
157 if (cur_msg[cur_len - 1] == '\n')
158 cur_len--;
159
160 /* concatenate cur_msg and new_msg into buf */
161 buf_len = cur_len + 1 + new_len;
162 buf = (char *) xmalloc(buf_len);
163 memcpy(buf, cur_msg, cur_len);
164 buf[cur_len] = '\n';
165 memcpy(buf + cur_len + 1, new_msg, new_len);
166
167 free(cur_msg);
168 free(new_msg);
169
170 /* create a new blob object from buf */
171 ret = write_sha1_file(buf, buf_len, "blob", cur_sha1);
172 free(buf);
173 return ret;
174}
175
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]176/*
177 * To insert a leaf_node:
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]178 * Search to the tree location appropriate for the given leaf_node's key:
179 * - If location is unused (NULL), store the tweaked pointer directly there
180 * - If location holds a note entry that matches the note-to-be-inserted, then
181 * concatenate the two notes.
182 * - If location holds a note entry that matches the subtree-to-be-inserted,
183 * then unpack the subtree-to-be-inserted into the location.
184 * - If location holds a matching subtree entry, unpack the subtree at that
185 * location, and restart the insert operation from that level.
186 * - Else, create a new int_node, holding both the node-at-location and the
187 * node-to-be-inserted, and store the new int_node into the location.
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]188 */
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]189static void note_tree_insert(struct int_node *tree, unsigned char n,
190 struct leaf_node *entry, unsigned char type)
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]191{
192 struct int_node *new_node;
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]193 struct leaf_node *l;
194 void **p = note_tree_search(&tree, &n, entry->key_sha1);
195
196 assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
197 l = (struct leaf_node *) CLR_PTR_TYPE(*p);
198 switch(GET_PTR_TYPE(*p)) {
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]199 case PTR_TYPE_NULL:
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]200 assert(!*p);
201 *p = SET_PTR_TYPE(entry, type);
202 return;
203 case PTR_TYPE_NOTE:
204 switch (type) {
205 case PTR_TYPE_NOTE:
206 if (!hashcmp(l->key_sha1, entry->key_sha1)) {
207 /* skip concatenation if l == entry */
208 if (!hashcmp(l->val_sha1, entry->val_sha1))
209 return;
210
211 if (concatenate_notes(l->val_sha1,
212 entry->val_sha1))
213 die("failed to concatenate note %s "
214 "into note %s for commit %s",
215 sha1_to_hex(entry->val_sha1),
216 sha1_to_hex(l->val_sha1),
217 sha1_to_hex(l->key_sha1));
218 free(entry);
219 return;
220 }
221 break;
222 case PTR_TYPE_SUBTREE:
223 if (!SUBTREE_SHA1_PREFIXCMP(l->key_sha1,
224 entry->key_sha1)) {
225 /* unpack 'entry' */
226 load_subtree(entry, tree, n);
227 free(entry);
228 return;
229 }
230 break;
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]231 }
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]232 break;
233 case PTR_TYPE_SUBTREE:
234 if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) {
235 /* unpack 'l' and restart insert */
236 *p = NULL;
237 load_subtree(l, tree, n);
238 free(l);
239 note_tree_insert(tree, n, entry, type);
240 return;
241 }
242 break;
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]243 }
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]244
245 /* non-matching leaf_node */
246 assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
247 GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
248 new_node = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
249 note_tree_insert(new_node, n + 1, l, GET_PTR_TYPE(*p));
250 *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
251 note_tree_insert(new_node, n + 1, entry, type);
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]252}
253
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]254/* Free the entire notes data contained in the given tree */
255static void note_tree_free(struct int_node *tree)
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]256{
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]257 unsigned int i;
258 for (i = 0; i < 16; i++) {
259 void *p = tree->a[i];
260 switch(GET_PTR_TYPE(p)) {
261 case PTR_TYPE_INTERNAL:
262 note_tree_free(CLR_PTR_TYPE(p));
263 /* fall through */
264 case PTR_TYPE_NOTE:
265 case PTR_TYPE_SUBTREE:
266 free(CLR_PTR_TYPE(p));
267 }
268 }
269}
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]270
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]271/*
272 * Convert a partial SHA1 hex string to the corresponding partial SHA1 value.
273 * - hex - Partial SHA1 segment in ASCII hex format
274 * - hex_len - Length of above segment. Must be multiple of 2 between 0 and 40
275 * - sha1 - Partial SHA1 value is written here
276 * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20
277 * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format).
278 * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2).
279 * Pads sha1 with NULs up to sha1_len (not included in returned length).
280 */
281static int get_sha1_hex_segment(const char *hex, unsigned int hex_len,
282 unsigned char *sha1, unsigned int sha1_len)
283{
284 unsigned int i, len = hex_len >> 1;
285 if (hex_len % 2 != 0 || len > sha1_len)
286 return -1;
287 for (i = 0; i < len; i++) {
288 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
289 if (val & ~0xff)
290 return -1;
291 *sha1++ = val;
292 hex += 2;
293 }
294 for (; i < sha1_len; i++)
295 *sha1++ = 0;
296 return len;
297}
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]298
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]299static void load_subtree(struct leaf_node *subtree, struct int_node *node,
300 unsigned int n)
301{
302 unsigned char commit_sha1[20];
303 unsigned int prefix_len;
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]304 void *buf;
305 struct tree_desc desc;
306 struct name_entry entry;
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]307
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]308 buf = fill_tree_descriptor(&desc, subtree->val_sha1);
309 if (!buf)
310 die("Could not read %s for notes-index",
311 sha1_to_hex(subtree->val_sha1));
312
313 prefix_len = subtree->key_sha1[19];
314 assert(prefix_len * 2 >= n);
315 memcpy(commit_sha1, subtree->key_sha1, prefix_len);
316 while (tree_entry(&desc, &entry)) {
317 int len = get_sha1_hex_segment(entry.path, strlen(entry.path),
318 commit_sha1 + prefix_len, 20 - prefix_len);
319 if (len < 0)
320 continue; /* entry.path is not a SHA1 sum. Skip */
321 len += prefix_len;
322
323 /*
324 * If commit SHA1 is complete (len == 20), assume note object
325 * If commit SHA1 is incomplete (len < 20), assume note subtree
326 */
327 if (len <= 20) {
328 unsigned char type = PTR_TYPE_NOTE;
329 struct leaf_node *l = (struct leaf_node *)
330 xcalloc(sizeof(struct leaf_node), 1);
331 hashcpy(l->key_sha1, commit_sha1);
332 hashcpy(l->val_sha1, entry.sha1);
333 if (len < 20) {
Johan Herland488bdf22009-12-03 03:53:54[diff] [blame]334 if (!S_ISDIR(entry.mode))
335 continue; /* entry cannot be subtree */
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]336 l->key_sha1[19] = (unsigned char) len;
337 type = PTR_TYPE_SUBTREE;
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]338 }
Johan Herlandef8db632009-10-09 10:22:09[diff] [blame]339 note_tree_insert(node, n, l, type);
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]340 }
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]341 }
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]342 free(buf);
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]343}
344
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]345static void initialize_notes(const char *notes_ref_name)
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]346{
347 unsigned char sha1[20], commit_sha1[20];
348 unsigned mode;
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]349 struct leaf_node root_tree;
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]350
351 if (!notes_ref_name || read_ref(notes_ref_name, commit_sha1) ||
352 get_tree_entry(commit_sha1, "", sha1, &mode))
353 return;
354
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]355 hashclr(root_tree.key_sha1);
356 hashcpy(root_tree.val_sha1, sha1);
357 load_subtree(&root_tree, &root_node, 0);
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]358}
359
360static unsigned char *lookup_notes(const unsigned char *commit_sha1)
361{
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]362 struct leaf_node *found = note_tree_find(&root_node, 0, commit_sha1);
363 if (found)
364 return found->val_sha1;
365 return NULL;
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]366}
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]367
Johan Herland27d57562009-10-09 10:22:06[diff] [blame]368void free_notes(void)
369{
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]370 note_tree_free(&root_node);
371 memset(&root_node, 0, sizeof(struct int_node));
Johan Herland27d57562009-10-09 10:22:06[diff] [blame]372 initialized = 0;
373}
374
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]375void get_commit_notes(const struct commit *commit, struct strbuf *sb,
Johan Herlandc56fcc82009-10-09 10:22:04[diff] [blame]376 const char *output_encoding, int flags)
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]377{
378 static const char utf8[] = "utf-8";
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]379 unsigned char *sha1;
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]380 char *msg, *msg_p;
381 unsigned long linelen, msglen;
382 enum object_type type;
383
384 if (!initialized) {
385 const char *env = getenv(GIT_NOTES_REF_ENVIRONMENT);
386 if (env)
387 notes_ref_name = getenv(GIT_NOTES_REF_ENVIRONMENT);
388 else if (!notes_ref_name)
389 notes_ref_name = GIT_NOTES_DEFAULT_REF;
Johan Herland23123ae2009-10-09 10:22:07[diff] [blame]390 initialize_notes(notes_ref_name);
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]391 initialized = 1;
392 }
393
Johannes Schindelinfd53c9e2009-10-09 10:21:59[diff] [blame]394 sha1 = lookup_notes(commit->object.sha1);
395 if (!sha1)
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]396 return;
397
398 if (!(msg = read_sha1_file(sha1, &type, &msglen)) || !msglen ||
399 type != OBJ_BLOB) {
400 free(msg);
401 return;
402 }
403
404 if (output_encoding && *output_encoding &&
405 strcmp(utf8, output_encoding)) {
406 char *reencoded = reencode_string(msg, output_encoding, utf8);
407 if (reencoded) {
408 free(msg);
409 msg = reencoded;
410 msglen = strlen(msg);
411 }
412 }
413
414 /* we will end the annotation by a newline anyway */
415 if (msglen && msg[msglen - 1] == '\n')
416 msglen--;
417
Johan Herlandc56fcc82009-10-09 10:22:04[diff] [blame]418 if (flags & NOTES_SHOW_HEADER)
419 strbuf_addstr(sb, "\nNotes:\n");
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]420
421 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
422 linelen = strchrnul(msg_p, '\n') - msg_p;
423
Johan Herlandc56fcc82009-10-09 10:22:04[diff] [blame]424 if (flags & NOTES_INDENT)
425 strbuf_addstr(sb, " ");
Johannes Schindelina97a7462009-10-09 10:21:57[diff] [blame]426 strbuf_add(sb, msg_p, linelen);
427 strbuf_addch(sb, '\n');
428 }
429
430 free(msg);
431}