ooh okay diva

next/core/hash.c

@@ -0,0 +1,71 @@
+#include <growl.h>
+
+#define FNV_OFFSET_BASIS 14695981039346656037ULL
+#define FNV_PRIME 1099511628211ULL
+
+uint64_t growl_hash_combine(uint64_t a, uint64_t b) {
+  return a ^ (b + 0x9e3779b97f4a7c15ULL + (a << 6) + (a >> 2));
+}
+
+uint64_t growl_hash_bytes(const uint8_t *data, size_t len) {
+  uint64_t hash = FNV_OFFSET_BASIS;
+  for (size_t i = 0; i < len; i++) {
+    hash ^= (uint64_t)data[i];
+    hash *= FNV_PRIME;
+  }
+  return hash;
+}
+
+static uint64_t hash_list(Growl obj) {
+  uint64_t hash = FNV_OFFSET_BASIS;
+  while (obj != GROWL_NIL) {
+    GrowlList *list = (GrowlList *)(GROWL_UNBOX(obj) + 1);
+    uint64_t head = growl_hash(list->head);
+    hash = growl_hash_combine(hash, head);
+    obj = list->tail;
+  }
+  return hash;
+}
+
+uint64_t growl_hash(Growl obj) {
+  if (obj == GROWL_NIL)
+    return 0;
+
+  if (GROWL_IMM(obj))
+    return obj;
+
+  GrowlObjectHeader *hdr = GROWL_UNBOX(obj);
+  switch (hdr->type) {
+  case GROWL_TYPE_STRING: {
+    GrowlString *str = (GrowlString *)(hdr + 1);
+    return growl_hash_bytes((uint8_t *)str->data, str->len);
+  }
+  case GROWL_TYPE_LIST: {
+    return hash_list(obj);
+  }
+  case GROWL_TYPE_TUPLE: {
+    GrowlTuple *tuple = (GrowlTuple *)(hdr + 1);
+    uint64_t hash = FNV_OFFSET_BASIS;
+    for (size_t i = 0; i < tuple->count; i++)
+      hash = growl_hash_combine(hash, growl_hash(tuple->data[i]));
+    return hash;
+  }
+  case GROWL_TYPE_QUOTATION: {
+    GrowlQuotation *quot = (GrowlQuotation *)(hdr + 1);
+    uint64_t hash = growl_hash_bytes(quot->data, quot->count);
+    if (quot->constants != GROWL_NIL)
+      hash = growl_hash_combine(hash, growl_hash(quot->constants));
+    return hash;
+  }
+  case GROWL_TYPE_COMPOSE: {
+    GrowlCompose *comp = (GrowlCompose *)(hdr + 1);
+    return growl_hash_combine(growl_hash(comp->first), growl_hash(comp->second));
+  }
+  case GROWL_TYPE_CURRY: {
+    GrowlCurry *curry = (GrowlCurry *)(hdr + 1);
+    return growl_hash_combine(growl_hash(curry->value), growl_hash(curry->callable));
+  }
+  default:
+    return obj;
+  }
+}