ruby0x1 · May 30, 2025 19:22 · Aug 10, 2023 · Oct 19, 2016 · Oct 19, 2016 · Oct 19, 2016
diff --git a/hash_fnv1a_constexpr.h b/hash_fnv1a_constexpr.h
@@ -13,9 +13,9 @@
   constexpr uint64_t prime_64_const = 0x100000001b3;
 
   inline constexpr uint32_t hash_32_fnv1a_const(const char* const str, const uint32_t value = val_32_const) noexcept {
-      return (str[0] == '\0') ? value : hash_32_fnv1a_const(&str[1], (value ^ uint32_t(str[0])) * prime_32_const);
+      return (str[0] == '\0') ? value : hash_32_fnv1a_const(&str[1], (value ^ uint32_t((uint8_t)str[0])) * prime_32_const);
   }
 
   inline constexpr uint64_t hash_64_fnv1a_const(const char* const str, const uint64_t value = val_64_const) noexcept {
-      return (str[0] == '\0') ? value : hash_64_fnv1a_const(&str[1], (value ^ uint64_t(str[0])) * prime_64_const);
+      return (str[0] == '\0') ? value : hash_64_fnv1a_const(&str[1], (value ^ uint64_t((uint8_t)str[0])) * prime_64_const);
   }
diff --git a/hash_fnv1a.h b/hash_fnv1a.h
@@ -4,6 +4,7 @@
 //fnv1a 32 and 64 bit hash functions
 // key is the data to hash, len is the size of the data (or how much of it to hash against)
 // code license: public domain or equivalent
+// post: https://notes.underscorediscovery.com/constexpr-fnv1a/
 
 inline const uint32_t hash_32_fnv1a(const void* key, const uint32_t len) {
 

diff --git a/hash_fnv1a_constexpr.h b/hash_fnv1a_constexpr.h
@@ -5,6 +5,7 @@
   // str should be a null terminated string literal, value should be left out 
   // e.g hash_32_fnv1a_const("example")
   // code license: public domain or equivalent
+  // post: https://notes.underscorediscovery.com/constexpr-fnv1a/
 
   constexpr uint32_t val_32_const = 0x811c9dc5;
   constexpr uint32_t prime_32_const = 0x1000193;

diff --git a/hash_fnv1a.h b/hash_fnv1a.h
@@ -1,3 +1,4 @@
+#pragma once
 #include <stdint.h>
 
 //fnv1a 32 and 64 bit hash functions

diff --git a/hash_fnv1a_constexpr.h b/hash_fnv1a_constexpr.h
@@ -1,3 +1,4 @@
+#pragma once
 #include <stdint.h>
 
   // FNV1a c++11 constexpr compile time hash functions, 32 and 64 bit

diff --git a/hash_fnv1a.h.cpp → hash_fnv1a.h b/hash_fnv1a.h.cpp → hash_fnv1a.h
diff --git a/hash_fnv1a_constexpr.h.cpp → hash_fnv1a_constexpr.h b/hash_fnv1a_constexpr.h.cpp → hash_fnv1a_constexpr.h
diff --git a/hash_constexpr_fnv1a.h.cpp → hash_fnv1a_constexpr.h.cpp b/hash_constexpr_fnv1a.h.cpp → hash_fnv1a_constexpr.h.cpp
diff --git a/hash_const_fnv1a.h.cpp → hash_constexpr_fnv1a.h.cpp b/hash_const_fnv1a.h.cpp → hash_constexpr_fnv1a.h.cpp
@@ -5,7 +5,7 @@
   // e.g hash_32_fnv1a_const("example")
   // code license: public domain or equivalent
 
-  constexpr uint32_t val_32_const = 0x811C9DC5;
+  constexpr uint32_t val_32_const = 0x811c9dc5;
   constexpr uint32_t prime_32_const = 0x1000193;
   constexpr uint64_t val_64_const = 0xcbf29ce484222325;
   constexpr uint64_t prime_64_const = 0x100000001b3;

diff --git a/hash_fnv1a.h.cpp b/hash_fnv1a.h.cpp
@@ -7,7 +7,7 @@
 inline const uint32_t hash_32_fnv1a(const void* key, const uint32_t len) {
 
     const char* data = (char*)key;
-    uint32_t hash = 0x811C9DC5;
+    uint32_t hash = 0x811c9dc5;
     uint32_t prime = 0x1000193;
 
     for(int i = 0; i < len; ++i) {

diff --git a/hash_const_fnv1a.h.cpp b/hash_const_fnv1a.h.cpp
@@ -5,8 +5,8 @@
   // e.g hash_32_fnv1a_const("example")
   // code license: public domain or equivalent
 
-  constexpr uint32_t val_32_const = 2166136261;
-  constexpr uint32_t prime_32_const = 16777619;
+  constexpr uint32_t val_32_const = 0x811C9DC5;
+  constexpr uint32_t prime_32_const = 0x1000193;
   constexpr uint64_t val_64_const = 0xcbf29ce484222325;
   constexpr uint64_t prime_64_const = 0x100000001b3;
 

diff --git a/hash_fnv1a.h.cpp b/hash_fnv1a.h.cpp
@@ -7,8 +7,8 @@
 inline const uint32_t hash_32_fnv1a(const void* key, const uint32_t len) {
 
     const char* data = (char*)key;
-    uint32_t hash = 2166136261;
-    uint32_t prime = 16777619;
+    uint32_t hash = 0x811C9DC5;
+    uint32_t prime = 0x1000193;
 
     for(int i = 0; i < len; ++i) {
         uint8_t value = data[i];

diff --git a/hash_const_fnv1a.h.cpp b/hash_const_fnv1a.h.cpp
@@ -3,7 +3,7 @@
   // FNV1a c++11 constexpr compile time hash functions, 32 and 64 bit
   // str should be a null terminated string literal, value should be left out 
   // e.g hash_32_fnv1a_const("example")
-  // license: public domain or equivalent
+  // code license: public domain or equivalent
 
   constexpr uint32_t val_32_const = 2166136261;
   constexpr uint32_t prime_32_const = 16777619;

diff --git a/hash_fnv1a.h.cpp b/hash_fnv1a.h.cpp
@@ -2,7 +2,7 @@
 
 //fnv1a 32 and 64 bit hash functions
 // key is the data to hash, len is the size of the data (or how much of it to hash against)
-// license: public domain or equivalent
+// code license: public domain or equivalent
 
 inline const uint32_t hash_32_fnv1a(const void* key, const uint32_t len) {
 

diff --git a/hash_const_fnv1a.h.cpp b/hash_const_fnv1a.h.cpp
@@ -3,6 +3,7 @@
   // FNV1a c++11 constexpr compile time hash functions, 32 and 64 bit
   // str should be a null terminated string literal, value should be left out 
   // e.g hash_32_fnv1a_const("example")
+  // license: public domain or equivalent
 
   constexpr uint32_t val_32_const = 2166136261;
   constexpr uint32_t prime_32_const = 16777619;

diff --git a/hash_fnv1a.h.cpp b/hash_fnv1a.h.cpp
@@ -1,5 +1,9 @@
 #include <stdint.h>
 
+//fnv1a 32 and 64 bit hash functions
+// key is the data to hash, len is the size of the data (or how much of it to hash against)
+// license: public domain or equivalent
+
 inline const uint32_t hash_32_fnv1a(const void* key, const uint32_t len) {
 
     const char* data = (char*)key;

diff --git a/hash_const_fnv1a.h.cpp b/hash_const_fnv1a.h.cpp
@@ -0,0 +1,18 @@
+#include <stdint.h>
+
+  // FNV1a c++11 constexpr compile time hash functions, 32 and 64 bit
+  // str should be a null terminated string literal, value should be left out 
+  // e.g hash_32_fnv1a_const("example")
+
+  constexpr uint32_t val_32_const = 2166136261;
+  constexpr uint32_t prime_32_const = 16777619;
+  constexpr uint64_t val_64_const = 0xcbf29ce484222325;
+  constexpr uint64_t prime_64_const = 0x100000001b3;
+
+  inline constexpr uint32_t hash_32_fnv1a_const(const char* const str, const uint32_t value = val_32_const) noexcept {
+      return (str[0] == '\0') ? value : hash_32_fnv1a_const(&str[1], (value ^ uint32_t(str[0])) * prime_32_const);
+  }
+
+  inline constexpr uint64_t hash_64_fnv1a_const(const char* const str, const uint64_t value = val_64_const) noexcept {
+      return (str[0] == '\0') ? value : hash_64_fnv1a_const(&str[1], (value ^ uint64_t(str[0])) * prime_64_const);
+  }
diff --git a/hash_fnv1a.h.cpp b/hash_fnv1a.h.cpp
@@ -0,0 +1,33 @@
+#include <stdint.h>
+
+inline const uint32_t hash_32_fnv1a(const void* key, const uint32_t len) {
+
+    const char* data = (char*)key;
+    uint32_t hash = 2166136261;
+    uint32_t prime = 16777619;
+
+    for(int i = 0; i < len; ++i) {
+        uint8_t value = data[i];
+        hash = hash ^ value;
+        hash *= prime;
+    }
+
+    return hash;
+
+} //hash_32_fnv1a
+
+inline const uint64_t hash_64_fnv1a(const void* key, const uint64_t len) {
+
+    const char* data = (char*)key;
+    uint64_t hash = 0xcbf29ce484222325;
+    uint64_t prime = 0x100000001b3;
+
+    for(int i = 0; i < len; ++i) {
+        uint8_t value = data[i];
+        hash = hash ^ value;
+        hash *= prime;
+    }
+
+    return hash;
+
+} //hash_64_fnv1a
No results found