Speed up git notes lookup
[git/dscho.git] / notes.c
blob2b66723f5fe52b4c32830904748679dd62a3cc47
1 #include "cache.h"
2 #include "commit.h"
3 #include "notes.h"
4 #include "refs.h"
5 #include "utf8.h"
6 #include "strbuf.h"
7 #include "tree-walk.h"
9 struct entry {
10 unsigned char commit_sha1[20];
11 unsigned char notes_sha1[20];
14 struct hash_map {
15 struct entry *entries;
16 off_t count, size;
19 static int initialized;
20 static struct hash_map hash_map;
22 static int hash_index(struct hash_map *map, const unsigned char *sha1)
24 int i = ((*(unsigned int *)sha1) % map->size);
26 for (;;) {
27 unsigned char *current = map->entries[i].commit_sha1;
29 if (!hashcmp(sha1, current))
30 return i;
32 if (is_null_sha1(current))
33 return -1 - i;
35 if (++i == map->size)
36 i = 0;
40 static void add_entry(const unsigned char *commit_sha1,
41 const unsigned char *notes_sha1)
43 int index;
45 if (hash_map.count + 1 > hash_map.size >> 1) {
46 int i, old_size = hash_map.size;
47 struct entry *old = hash_map.entries;
49 hash_map.size = old_size ? old_size << 1 : 64;
50 hash_map.entries = (struct entry *)
51 xcalloc(sizeof(struct entry), hash_map.size);
53 for (i = 0; i < old_size; i++)
54 if (!is_null_sha1(old[i].commit_sha1)) {
55 index = -1 - hash_index(&hash_map,
56 old[i].commit_sha1);
57 memcpy(hash_map.entries + index, old + i,
58 sizeof(struct entry));
60 free(old);
63 index = hash_index(&hash_map, commit_sha1);
64 if (index < 0) {
65 index = -1 - index;
66 hash_map.count++;
69 hashcpy(hash_map.entries[index].commit_sha1, commit_sha1);
70 hashcpy(hash_map.entries[index].notes_sha1, notes_sha1);
73 static void initialize_hash_map(const char *notes_ref_name)
75 unsigned char sha1[20], commit_sha1[20];
76 unsigned mode;
77 struct tree_desc desc;
78 struct name_entry entry;
79 void *buf;
81 if (!notes_ref_name || read_ref(notes_ref_name, commit_sha1) ||
82 get_tree_entry(commit_sha1, "", sha1, &mode))
83 return;
85 buf = fill_tree_descriptor(&desc, sha1);
86 if (!buf)
87 die("Could not read %s for notes-index", sha1_to_hex(sha1));
89 while (tree_entry(&desc, &entry))
90 if (!get_sha1(entry.path, commit_sha1))
91 add_entry(commit_sha1, entry.sha1);
92 free(buf);
95 static unsigned char *lookup_notes(const unsigned char *commit_sha1)
97 int index;
99 if (!hash_map.size)
100 return NULL;
102 index = hash_index(&hash_map, commit_sha1);
103 if (index < 0)
104 return NULL;
105 return hash_map.entries[index].notes_sha1;
108 void get_commit_notes(const struct commit *commit, struct strbuf *sb,
109 const char *output_encoding)
111 static const char utf8[] = "utf-8";
112 unsigned char *sha1;
113 char *msg, *msg_p;
114 unsigned long linelen, msglen;
115 enum object_type type;
117 if (!initialized) {
118 const char *env = getenv(GIT_NOTES_REF_ENVIRONMENT);
119 if (env)
120 notes_ref_name = getenv(GIT_NOTES_REF_ENVIRONMENT);
121 else if (!notes_ref_name)
122 notes_ref_name = GIT_NOTES_DEFAULT_REF;
123 initialize_hash_map(notes_ref_name);
124 initialized = 1;
127 sha1 = lookup_notes(commit->object.sha1);
128 if (!sha1)
129 return;
131 if (!(msg = read_sha1_file(sha1, &type, &msglen)) || !msglen ||
132 type != OBJ_BLOB) {
133 free(msg);
134 return;
137 if (output_encoding && *output_encoding &&
138 strcmp(utf8, output_encoding)) {
139 char *reencoded = reencode_string(msg, output_encoding, utf8);
140 if (reencoded) {
141 free(msg);
142 msg = reencoded;
143 msglen = strlen(msg);
147 /* we will end the annotation by a newline anyway */
148 if (msglen && msg[msglen - 1] == '\n')
149 msglen--;
151 strbuf_addstr(sb, "\nNotes:\n");
153 for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
154 linelen = strchrnul(msg_p, '\n') - msg_p;
156 strbuf_addstr(sb, " ");
157 strbuf_add(sb, msg_p, linelen);
158 strbuf_addch(sb, '\n');
161 free(msg);