STATIC void free_hash_table(hashtable *ht)
{
hashelem *hp, *thp;
hp = ht->first;
while(hp != NULL) {
thp = hp;
hp = hp->nextelem;
free_hash_item(&thp);
}
free(ht->table);
free(ht);
}
int
filehash_get(const unsigned char *path, unsigned char *val)
{
unsigned long p_hash;
unsigned int idx, i, min_i;
struct hash_entry *p, *q;
FILE *f = 0;
unsigned min_tick;
ASSERT(path);
p_hash = get_hash(path);
idx = p_hash % HASH_SIZE;
while (hash_table[idx] && hash_table[idx]->path_hash == p_hash
&& strcmp(hash_table[idx]->path, path) != 0) {
idx = (idx + HASH_STEP) % HASH_SIZE;
}
if (hash_table[idx] && hash_table[idx]->path_hash == p_hash) {
// hit!
if (!file_stamp_is_updated(path, hash_table[idx]->stamp)) {
info("entry <%s> is in hash table and is not changed", path);
memcpy(val, hash_table[idx]->sha1_hash, SHA1_SIZE);
hash_table[idx]->tick = cur_tick++;
return 0;
}
// update the hash code, maybe removing an item
info("entry <%s> is in hash table and is CHANGED!", path);
hash_table[idx]->stamp = file_stamp_update(path, hash_table[idx]->stamp);
if (!hash_table[idx]->stamp || !(f = fopen(path, "rb"))
|| sha_stream(f, hash_table[idx]->sha1_hash)) {
// file no longer exists or I/O error
if (f) fclose(f);
p = remove_hash_item(idx);
free_hash_item(p);
hash_use--;
return -1;
}
// recalculate the hash
fclose(f);
memcpy(val, hash_table[idx]->sha1_hash, SHA1_SIZE);
hash_table[idx]->tick = cur_tick++;
return 0;
}
// no entry in the hash table
XCALLOC(p, 1);
if (!(p->stamp = file_stamp_get(path))
|| !(f = fopen(path, "rb"))
|| sha_stream(f, p->sha1_hash)) {
if (f) fclose(f);
free_hash_item(p);
return -1;
}
fclose(f);
p->path_hash = p_hash;
p->path = xstrdup(path);
p->tick = cur_tick++;
memcpy(val, p->sha1_hash, SHA1_SIZE);
if (hash_use < HASH_CAP) {
info("entry <%s> is not in the hash table - adding", path);
add_hash_item(p);
hash_use++;
return 0;
}
// find the least recently used entry and remove it
info("entry <%s> is not in the hash table - REPLACING", path);
min_i = -1;
min_tick = cur_tick;
for (i = 0; i < HASH_SIZE; i++)
if (hash_table[i] && hash_table[i]->tick < min_tick) {
min_i = i;
min_tick = hash_table[i]->tick;
}
ASSERT(min_i >= 0);
q = remove_hash_item(min_i);
free_hash_item(q);
add_hash_item(p);
return 0;
}