Merge branch 'nd/doc-check-ref-format-typo' into maint
[git/debian.git] / name-hash.c
blob332ba956e7edec6c6fbe10f346ec08fc469b846f
1 /*
2 * name-hash.c
4 * Hashing names in the index state
6 * Copyright (C) 2008 Linus Torvalds
7 */
8 #define NO_THE_INDEX_COMPATIBILITY_MACROS
9 #include "cache.h"
11 struct dir_entry {
12 struct hashmap_entry ent;
13 struct dir_entry *parent;
14 int nr;
15 unsigned int namelen;
16 char name[FLEX_ARRAY];
19 static int dir_entry_cmp(const struct dir_entry *e1,
20 const struct dir_entry *e2, const char *name)
22 return e1->namelen != e2->namelen || strncasecmp(e1->name,
23 name ? name : e2->name, e1->namelen);
26 static struct dir_entry *find_dir_entry(struct index_state *istate,
27 const char *name, unsigned int namelen)
29 struct dir_entry key;
30 hashmap_entry_init(&key, memihash(name, namelen));
31 key.namelen = namelen;
32 return hashmap_get(&istate->dir_hash, &key, name);
35 static struct dir_entry *hash_dir_entry(struct index_state *istate,
36 struct cache_entry *ce, int namelen)
39 * Throw each directory component in the hash for quick lookup
40 * during a git status. Directory components are stored without their
41 * closing slash. Despite submodules being a directory, they never
42 * reach this point, because they are stored
43 * in index_state.name_hash (as ordinary cache_entries).
45 struct dir_entry *dir;
47 /* get length of parent directory */
48 while (namelen > 0 && !is_dir_sep(ce->name[namelen - 1]))
49 namelen--;
50 if (namelen <= 0)
51 return NULL;
52 namelen--;
54 /* lookup existing entry for that directory */
55 dir = find_dir_entry(istate, ce->name, namelen);
56 if (!dir) {
57 /* not found, create it and add to hash table */
58 dir = xcalloc(1, sizeof(struct dir_entry) + namelen + 1);
59 hashmap_entry_init(dir, memihash(ce->name, namelen));
60 dir->namelen = namelen;
61 strncpy(dir->name, ce->name, namelen);
62 hashmap_add(&istate->dir_hash, dir);
64 /* recursively add missing parent directories */
65 dir->parent = hash_dir_entry(istate, ce, namelen);
67 return dir;
70 static void add_dir_entry(struct index_state *istate, struct cache_entry *ce)
72 /* Add reference to the directory entry (and parents if 0). */
73 struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce));
74 while (dir && !(dir->nr++))
75 dir = dir->parent;
78 static void remove_dir_entry(struct index_state *istate, struct cache_entry *ce)
81 * Release reference to the directory entry. If 0, remove and continue
82 * with parent directory.
84 struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce));
85 while (dir && !(--dir->nr)) {
86 struct dir_entry *parent = dir->parent;
87 hashmap_remove(&istate->dir_hash, dir, NULL);
88 free(dir);
89 dir = parent;
93 static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
95 if (ce->ce_flags & CE_HASHED)
96 return;
97 ce->ce_flags |= CE_HASHED;
98 hashmap_entry_init(ce, memihash(ce->name, ce_namelen(ce)));
99 hashmap_add(&istate->name_hash, ce);
101 if (ignore_case)
102 add_dir_entry(istate, ce);
105 static int cache_entry_cmp(const struct cache_entry *ce1,
106 const struct cache_entry *ce2, const void *remove)
109 * For remove_name_hash, find the exact entry (pointer equality); for
110 * index_file_exists, find all entries with matching hash code and
111 * decide whether the entry matches in same_name.
113 return remove ? !(ce1 == ce2) : 0;
116 static void lazy_init_name_hash(struct index_state *istate)
118 int nr;
120 if (istate->name_hash_initialized)
121 return;
122 hashmap_init(&istate->name_hash, (hashmap_cmp_fn) cache_entry_cmp,
123 istate->cache_nr);
124 hashmap_init(&istate->dir_hash, (hashmap_cmp_fn) dir_entry_cmp, 0);
125 for (nr = 0; nr < istate->cache_nr; nr++)
126 hash_index_entry(istate, istate->cache[nr]);
127 istate->name_hash_initialized = 1;
130 void add_name_hash(struct index_state *istate, struct cache_entry *ce)
132 if (istate->name_hash_initialized)
133 hash_index_entry(istate, ce);
136 void remove_name_hash(struct index_state *istate, struct cache_entry *ce)
138 if (!istate->name_hash_initialized || !(ce->ce_flags & CE_HASHED))
139 return;
140 ce->ce_flags &= ~CE_HASHED;
141 hashmap_remove(&istate->name_hash, ce, ce);
143 if (ignore_case)
144 remove_dir_entry(istate, ce);
147 static int slow_same_name(const char *name1, int len1, const char *name2, int len2)
149 if (len1 != len2)
150 return 0;
152 while (len1) {
153 unsigned char c1 = *name1++;
154 unsigned char c2 = *name2++;
155 len1--;
156 if (c1 != c2) {
157 c1 = toupper(c1);
158 c2 = toupper(c2);
159 if (c1 != c2)
160 return 0;
163 return 1;
166 static int same_name(const struct cache_entry *ce, const char *name, int namelen, int icase)
168 int len = ce_namelen(ce);
171 * Always do exact compare, even if we want a case-ignoring comparison;
172 * we do the quick exact one first, because it will be the common case.
174 if (len == namelen && !memcmp(name, ce->name, len))
175 return 1;
177 if (!icase)
178 return 0;
180 return slow_same_name(name, namelen, ce->name, len);
183 int index_dir_exists(struct index_state *istate, const char *name, int namelen)
185 struct dir_entry *dir;
187 lazy_init_name_hash(istate);
188 dir = find_dir_entry(istate, name, namelen);
189 return dir && dir->nr;
192 void adjust_dirname_case(struct index_state *istate, char *name)
194 const char *startPtr = name;
195 const char *ptr = startPtr;
197 lazy_init_name_hash(istate);
198 while (*ptr) {
199 while (*ptr && *ptr != '/')
200 ptr++;
202 if (*ptr == '/') {
203 struct dir_entry *dir;
205 ptr++;
206 dir = find_dir_entry(istate, name, ptr - name + 1);
207 if (dir) {
208 memcpy((void *)startPtr, dir->name + (startPtr - name), ptr - startPtr);
209 startPtr = ptr;
215 struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int icase)
217 struct cache_entry *ce;
219 lazy_init_name_hash(istate);
221 ce = hashmap_get_from_hash(&istate->name_hash,
222 memihash(name, namelen), NULL);
223 while (ce) {
224 if (same_name(ce, name, namelen, icase))
225 return ce;
226 ce = hashmap_get_next(&istate->name_hash, ce);
228 return NULL;
231 void free_name_hash(struct index_state *istate)
233 if (!istate->name_hash_initialized)
234 return;
235 istate->name_hash_initialized = 0;
237 hashmap_free(&istate->name_hash, 0);
238 hashmap_free(&istate->dir_hash, 1);