1 files changed, 163 insertions, 0 deletions
diff --git a/hashfuncs.c b/hashfuncs.c
new file mode 100644
index 0000000..01a1be1
--- /dev/null
+++ b/hashfuncs.c
@@ -0,0 +1,163 @@
+/* hashfuncs.c
+ *
+ * Hash Functions
+ *
+ * notes: aphash may not be correct 
+ *
+ */
+
+#include "hashfuncs.h"
+
+/* does not mod by the size of the hash table, simple and clever,
+ * this allows seamless retrieval of collided elements */
+unsigned int defaulthash(const char *key)
+{
+    unsigned int hash = 0;
+    
+    for ( ; *key; key++)
+        hash += (unsigned char) *key;
+
+    return hash;
+}
+
+unsigned int rshash(const char *key)
+{
+    unsigned int b = 378551;
+    unsigned int a = 63689;
+    unsigned int hash = 0;
+
+    for ( ; *key; key++)
+    {
+        hash = hash * a + (*key);
+        a = a * b;
+    }
+
+    return hash;
+}
+
+unsigned int jshash(const char *key)
+{
+    unsigned int hash = 1315423911;
+
+    for ( ; *key; key++)
+        hash ^= ((hash << 5) + ((unsigned char) (*key)) + (hash >> 2));
+
+    return hash;
+}
+
+unsigned int pjwhash(const char *key)
+{
+    const unsigned int BitsInUnsignedInt = (unsigned int) (sizeof(unsigned int) * 8);
+    const unsigned int ThreeQuarters = (unsigned int) ((BitsInUnsignedInt  * 3) / 4);
+    const unsigned int OneEighth = (unsigned int) (BitsInUnsignedInt / 8);
+    const unsigned int HighBits = (unsigned int) (0xFFFFFFFF) << (BitsInUnsignedInt - OneEighth);
+    unsigned int hash = 0;
+    unsigned int test = 0;
+
+    for ( ; *key; key++)
+    {
+        hash = (hash << OneEighth) + (*key);
+        if ((test = hash & HighBits) != 0)
+            hash = (( hash ^ (test >> ThreeQuarters)) & (~HighBits));
+    }
+
+    return hash;
+}
+
+unsigned int elfhash(const char *key)
+{
+    unsigned int hash = 0;
+    unsigned int x = 0;
+
+    for ( ; *key; key++)
+    {
+        hash = (hash << 4) + (*key);
+
+        if ((x = hash & 0xF0000000L) != 0)
+            hash ^= (x >> 24);
+
+      hash &= ~x;
+    }
+
+    return hash;
+}
+
+unsigned int bkdrhash(const char *key)
+{
+    unsigned int seed = 131; /* 31 131 1313 13131 131313 etc.. */
+    unsigned int hash = 0;
+
+    for ( ; *key; key++)
+        hash = (hash * seed) + (*key);
+ 
+    return hash;
+}
+
+unsigned int sdbmhash(const char *key)
+{
+    unsigned int hash = 0;
+
+    for ( ; *key; key++)
+        hash = (*key) + (hash << 6) + (hash << 16) - hash;
+
+    return hash;
+}
+
+unsigned int djbhash(const char *key)
+{
+    unsigned int hash = 5381;
+
+    for ( ; *key; key++)
+        hash = ((hash << 5) + hash) + (*key);
+
+    return hash;
+}
+
+unsigned int dekhash(const char *key)
+{
+    unsigned int hash = strlen(key);
+
+    for ( ; *key; key++)
+        hash = ((hash << 5) ^ (hash >> 27)) ^ (*key);
+
+    return hash;
+}
+
+unsigned int bphash(const char *key)
+{
+    unsigned int hash = 0;
+
+    for ( ; *key; key++)
+        hash = hash << 7 ^ (*key);
+
+    return hash;
+}
+
+unsigned int fnvhash(const char *key)
+{
+    const unsigned int fnv_prime = 0x811C9DC5;
+    unsigned int hash = 0;
+
+    for ( ; *key; key++)
+    {
+        hash *= fnv_prime;
+        hash ^= (*key);
+    }
+
+    return hash;
+}
+
+unsigned int aphash(const char *key)
+{
+    unsigned int hash = 0xAAAAAAAA;
+    unsigned int i = strlen(key);
+
+    for ( ; *key; key++)
+    {
+        hash ^= ((i & 1) == 0) ? (  (hash <<  7) ^ (*key) * (hash >> 3)) :
+                               (~((hash << 11) + ((*key) ^ (hash >> 5))));
+    }
+
+    return hash;
+}
+