1 files changed, 49 insertions, 0 deletions
diff --git a/libparc/parc/algol/parc_HashCode.c b/libparc/parc/algol/parc_HashCode.c
new file mode 100755
index 00000000..8554429c
--- /dev/null
+++ b/libparc/parc/algol/parc_HashCode.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ */
+#include <config.h>
+
+#include <parc/algol/parc_HashCode.h>
+
+#if PARCHashCodeSize == 64
+static const PARCHashCode _fnv1a_prime = 0x00000100000001B3ULL;
+const PARCHashCode parcHashCode_InitialValue = 0xCBF29CE484222325ULL;
+#else
+static const PARCHashCode _fnv1a_prime = 0x01000193;
+const PARCHashCode parcHashCode_InitialValue = 0x811C9DC5;
+#endif
+
+PARCHashCode
+parcHashCode_HashImpl(const uint8_t *memory, size_t length, PARCHashCode initialValue)
+{
+    // Standard FNV 64-bit prime: see http://www.isthe.com/chongo/tech/comp/fnv/#FNV-param
+
+    PARCHashCode hash = initialValue;
+
+    for (size_t i = 0; i < length; i++) {
+        hash = hash ^ memory[i];
+        hash = hash * _fnv1a_prime;
+    }
+
+    return hash;
+}
+
+PARCHashCode
+parcHashCode_HashHashCode(PARCHashCode initialValue, PARCHashCode update)
+{
+    return parcHashCode_HashImpl((uint8_t *) &update, sizeof(PARCHashCode), initialValue);
+}