hashmap: allow memihash computation to be continued

diff --git a/hashmap.c b/hashmap.c
index b10b642229ca0c3e6eb27142f080921dd5c3aece..93793cb954e4bde0df9c57131a782c32fc15dc36 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