Commit ab73a9d1 authored by Karsten Blees's avatar Karsten Blees Committed by Junio C Hamano

hashmap: add simplified hashmap_get_from_hash() API

Hashmap entries are typically looked up by just a key. The hashmap_get()
API expects an initialized entry structure instead, to support compound
keys. This flexibility is currently only needed by find_dir_entry() in
name-hash.c (and compat/win32/fscache.c in the msysgit fork). All other
(currently five) call sites of hashmap_get() have to set up a near emtpy
entry structure, resulting in duplicate code like this:

  struct hashmap_entry keyentry;
  hashmap_entry_init(&keyentry, hash(key));
  return hashmap_get(map, &keyentry, key);

Add a hashmap_get_from_hash() API that allows hashmap lookups by just
specifying the key and its hash code, i.e.:

  return hashmap_get_from_hash(map, hash(key), key);
Signed-off-by: default avatarKarsten Blees <>
Signed-off-by: default avatarJunio C Hamano <>
parent aa420c48
......@@ -118,6 +118,20 @@ hashmap_entry) that has at least been initialized with the proper hash code
If an entry with matching hash code is found, `key` and `keydata` are passed
to `hashmap_cmp_fn` to decide whether the entry matches the key.
`void *hashmap_get_from_hash(const struct hashmap *map, unsigned int hash, const void *keydata)`::
Returns the hashmap entry for the specified hash code and key data,
or NULL if not found.
`map` is the hashmap structure.
`hash` is the hash code of the entry to look up.
If an entry with matching hash code is found, `keydata` is passed to
`hashmap_cmp_fn` to decide whether the entry matches the key. The
`entry_or_key` parameter points to a bogus hashmap_entry structure that
should not be used in the comparison.
`void *hashmap_get_next(const struct hashmap *map, const void *entry)`::
Returns the next equal hashmap entry, or NULL if not found. This can be
......@@ -58,9 +58,7 @@ static int commit_name_cmp(const struct commit_name *cn1,
static inline struct commit_name *find_commit_name(const unsigned char *peeled)
struct commit_name key;
hashmap_entry_init(&key, sha1hash(peeled));
return hashmap_get(&names, &key, peeled);
return hashmap_get_from_hash(&names, sha1hash(peeled), peeled);
static int replace_name(struct commit_name *e,
......@@ -257,15 +257,14 @@ static int find_identical_files(struct hashmap *srcs,
int renames = 0;
struct diff_filespec *target = rename_dst[dst_index].two;
struct file_similarity *p, *best, dst;
struct file_similarity *p, *best = NULL;
int i = 100, best_score = -1;
* Find the best source match for specified destination.
best = NULL;
hashmap_entry_init(&dst, hash_filespec(target));
for (p = hashmap_get(srcs, &dst, NULL); p; p = hashmap_get_next(srcs, p)) {
p = hashmap_get_from_hash(srcs, hash_filespec(target), NULL);
for (; p; p = hashmap_get_next(srcs, p)) {
int score;
struct diff_filespec *source = p->filespec;
......@@ -68,6 +68,14 @@ extern void *hashmap_put(struct hashmap *map, void *entry);
extern void *hashmap_remove(struct hashmap *map, const void *key,
const void *keydata);
static inline void *hashmap_get_from_hash(const struct hashmap *map,
unsigned int hash, const void *keydata)
struct hashmap_entry key;
hashmap_entry_init(&key, hash);
return hashmap_get(map, &key, keydata);
/* hashmap_iter functions */
extern void hashmap_iter_init(struct hashmap *map, struct hashmap_iter *iter);
......@@ -213,12 +213,11 @@ struct cache_entry *index_dir_exists(struct index_state *istate, const char *nam
struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int icase)
struct cache_entry *ce;
struct hashmap_entry key;
hashmap_entry_init(&key, memihash(name, namelen));
ce = hashmap_get(&istate->name_hash, &key, NULL);
ce = hashmap_get_from_hash(&istate->name_hash,
memihash(name, namelen), NULL);
while (ce) {
if (same_name(ce, name, namelen, icase))
return ce;
......@@ -115,9 +115,8 @@ static void perf_hashmap(unsigned int method, unsigned int rounds)
for (j = 0; j < rounds; j++) {
for (i = 0; i < TEST_SIZE; i++) {
struct hashmap_entry key;
hashmap_entry_init(&key, hashes[i]);
hashmap_get(&map, &key, entries[i]->key);
hashmap_get_from_hash(&map, hashes[i],
......@@ -199,12 +198,8 @@ int main(int argc, char *argv[])
} else if (!strcmp("get", cmd) && l1) {
/* setup static key */
struct hashmap_entry key;
hashmap_entry_init(&key, hash);
/* lookup entry in hashmap */
entry = hashmap_get(&map, &key, p1);
entry = hashmap_get_from_hash(&map, hash, p1);
/* print result */
if (!entry)
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