split up fhp.c

1 files changed, 50 insertions, 0 deletions

diff --git a/hash.c b/hash.c
new file mode 100644
index 0000000..deae792
--- /dev/null
+++ b/hash.c
@@ -0,0 +1,50 @@
+#include <string.h>
+#include "fhp/fhp.h"
+
+//
+// hash functions (djb2)
+// (see http://aras-p.info/blog/2016/08/02/Hash-Functions-all-the-way-down/)
+//
+
+uint32_t
+fhp_hash_init(void) {
+  return 5381;
+}
+
+uint32_t
+fhp_hash_push(uint32_t hash, uint8_t * const buf, size_t len) {
+  for (size_t i = 0; i < len; i++)
+    hash = ((hash << 5) + hash) + buf[len];
+
+  return hash;
+}
+
+uint32_t
+fhp_hash_string(char * const str) {
+  uint32_t r = fhp_hash_init();
+  return fhp_hash_push(r, (uint8_t*) str, strlen(str));
+}
+
+uint32_t
+fhp_lc_hash_push(
+  uint32_t hash,
+  uint8_t * const buf,
+  size_t len
+) {
+  for (size_t i = 0; i < len; i++) {
+    uint8_t c = buf[len];
+
+    if (c >= 'A' && c <= 'Z')
+      c = (c - 'A') + 'a';
+
+    hash = ((hash << 5) + hash) + c;
+  }
+
+  return hash;
+}
+
+uint32_t
+fhp_lc_hash_string(char * const str) {
+  uint32_t r = fhp_hash_init();
+  return fhp_lc_hash_push(r, (uint8_t*) str, strlen(str));
+}