Added coucal_hash_data()

2 files changed, 17 insertions, 7 deletions

diff --git a/src/coucal.c b/src/coucal.c
index 9654431..2567d0c 100644
--- a/src/coucal.c
+++ b/src/coucal.c
@@ -350,7 +350,8 @@ static void coucal_log_stats(coucal hashtable) {
 }
 
 /* default hash function when key is a regular C-string */
-coucal_hashkeys coucal_hash_string(const char *name) {
+coucal_hashkeys coucal_hash_data(const void *data_, size_t size) {
+  const unsigned char *const data = (const unsigned char *) data_;
 #if HTS_INTHASH_USES_MD5 == 1
   /* compute a regular MD5 and extract two 32-bit integers */
   MD5_CTX ctx;
@@ -362,8 +363,7 @@ coucal_hashkeys coucal_hash_string(const char *name) {
 
   /* compute MD5 */
   MD5Init(&ctx, 0);
-  MD5Update(&ctx, (const unsigned char *) name,
-    (unsigned int) strlen(name));
+  MD5Update(&ctx, data, (unsigned int) size);
   MD5Final(u.md5digest, &ctx);
 
   /* mix mix mix */
@@ -381,7 +381,7 @@ coucal_hashkeys coucal_hash_string(const char *name) {
     uint32_t result[4];
     coucal_hashkeys hashes;
   } u;
-  MurmurHash3_x86_128(name, (const int) strlen(name),
+  MurmurHash3_x86_128(data, (const int) size,
                       42, &u.result) ;
 
   /* mix mix mix */
@@ -408,8 +408,8 @@ coucal_hashkeys coucal_hash_string(const char *name) {
   /* compute the hashes ; second variant is using xored data */
   h1 = FNV1_OFFSET_BASIS;
   h2 = ~FNV1_OFFSET_BASIS;
-  for(i = 0 ; name[i] != '\0' ; i++) {
-    const unsigned char c1 = name[i];
+  for(i = 0 ; i < size ; i++) {
+    const unsigned char c1 = data[i];
     const unsigned char c2 = ~c1;
     h1 = ( h1 * FNV1_PRIME ) ^ c1;
     h2 = ( h2 * FNV1_PRIME ) ^ c2;
@@ -431,6 +431,10 @@ coucal_hashkeys coucal_hash_string(const char *name) {
 #endif
 }
 
+coucal_hashkeys coucal_hash_string(const char *name) {
+  return coucal_hash_data(name, strlen(name));
+}
+
 static INTHASH_INLINE coucal_hashkeys coucal_calc_hashes(coucal hashtable, 
                                                          coucal_key_const value) {
   return hashtable->custom.key.hash == NULL 
diff --git a/src/coucal.h b/src/coucal.h
index 9a7336f..0ea9486 100644
--- a/src/coucal.h
+++ b/src/coucal.h
@@ -433,11 +433,17 @@ COUCAL_EXTERN coucal_item *coucal_enum_next(struct_coucal_enum * e);
 
 /**
  * Compute a hash, given a string. This is the default function used for
- * hashing keys, which are by default strings.
+ * hashing keys, which are by default strings. This function uses
+ * coucal_hash_data() as backend.
  **/
 COUCAL_EXTERN coucal_hashkeys coucal_hash_string(const char *value);
 
 /**
+ * Compute a hash, given an opaque buffer.
+ **/
+COUCAL_EXTERN coucal_hashkeys coucal_hash_data(const void *data, size_t size);
+
+/**
  * Set default global assertion failure handler.
  * The handler will be used if no specific handler was defined in the
  * hashtable itself.