hashmap.h: compare function has access to a data field

diff --git a/hashmap.c b/hashmap.c
index b10b642229ca0c3e6eb27142f080921dd5c3aece..9b6a12859be67a09685f13310f9769df260d558d 100644 (file)
--- a/hashmap.c
+++ b/hashmap.c
@@ -50,6 +50,23 @@ unsigned int memihash(const void *buf, size_t len)
        return hash;
 }
 
+/*
+ * Incoporate another chunk of data into a memihash
+ * computation.
+ */
+unsigned int memihash_cont(unsigned int hash_seed, const void *buf, size_t len)
+{
+       unsigned int hash = hash_seed;
+       unsigned char *ucbuf = (unsigned char *) buf;
+       while (len--) {
+               unsigned int c = *ucbuf++;
+               if (c >= 'a' && c <= 'z')
+                       c -= 'a' - 'A';
+               hash = (hash * FNV32_PRIME) ^ c;
+       }
+       return hash;
+}
+
 #define HASHMAP_INITIAL_SIZE 64
 /* grow / shrink by 2^2 */
 #define HASHMAP_RESIZE_BITS 2
@@ -78,7 +95,9 @@ static inline int entry_equals(const struct hashmap *map,
                const struct hashmap_entry *e1, const struct hashmap_entry *e2,
                const void *keydata)
 {
-       return (e1 == e2) || (e1->hash == e2->hash && !map->cmpfn(e1, e2, keydata));
+       return (e1 == e2) ||
+              (e1->hash == e2->hash &&
+               !map->cmpfn(map->cmpfn_data, e1, e2, keydata));
 }
 
 static inline unsigned int bucket(const struct hashmap *map,
@@ -87,11 +106,19 @@ static inline unsigned int bucket(const struct hashmap *map,
        return key->hash & (map->tablesize - 1);
 }
 
+int hashmap_bucket(const struct hashmap *map, unsigned int hash)
+{
+       return hash & (map->tablesize - 1);
+}
+
 static void rehash(struct hashmap *map, unsigned int newsize)
 {
        unsigned int i, oldsize = map->tablesize;
        struct hashmap_entry **oldtable = map->table;
 
+       if (map->disallow_rehash)
+               return;
+
        alloc_table(map, newsize);
        for (i = 0; i < oldsize; i++) {
                struct hashmap_entry *e = oldtable[i];
@@ -115,17 +142,23 @@ static inline struct hashmap_entry **find_entry_ptr(const struct hashmap *map,
        return e;
 }
 
-static int always_equal(const void *unused1, const void *unused2, const void *unused3)
+static int always_equal(const void *unused_cmp_data,
+                       const void *unused1,
+                       const void *unused2,
+                       const void *unused_keydata)
 {
        return 0;
 }
 
 void hashmap_init(struct hashmap *map, hashmap_cmp_fn equals_function,
-               size_t initial_size)
+               const void *cmpfn_data, size_t initial_size)
 {
        unsigned int size = HASHMAP_INITIAL_SIZE;
-       map->size = 0;
+
+       memset(map, 0, sizeof(*map));
+
        map->cmpfn = equals_function ? equals_function : always_equal;
+       map->cmpfn_data = cmpfn_data;
 
        /* calculate initial table size and allocate the table */
        initial_size = (unsigned int) ((uint64_t) initial_size * 100
@@ -233,7 +266,8 @@ struct pool_entry {
        unsigned char data[FLEX_ARRAY];
 };
 
-static int pool_entry_cmp(const struct pool_entry *e1,
+static int pool_entry_cmp(const void *unused_cmp_data,
+                         const struct pool_entry *e1,
                          const struct pool_entry *e2,
                          const unsigned char *keydata)
 {
@@ -248,7 +282,7 @@ const void *memintern(const void *data, size_t len)
 
        /* initialize string pool hashmap */
        if (!map.tablesize)
-               hashmap_init(&map, (hashmap_cmp_fn) pool_entry_cmp, 0);
+               hashmap_init(&map, (hashmap_cmp_fn) pool_entry_cmp, NULL, 0);
 
        /* lookup interned string in pool */
        hashmap_entry_init(&key, memhash(data, len));