Initial project import

tools/v/vlib/hash/fnv1a/fnv1a.v

@@ -0,0 +1,97 @@
+module fnv1a
+
+// This module implements a FNV-1a hash.
+// (see https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function)
+
+const fnv64_prime = u64(1099511628211)
+const fnv64_offset_basis = u64(14695981039346656037)
+const fnv32_offset_basis = u32(2166136261)
+const fnv32_prime = u32(16777619)
+
+// sum32 returns a fnv1a hash of the string, described by `data`
+@[direct_array_access; inline]
+pub fn sum32_string(data string) u32 {
+	mut hash := fnv32_offset_basis
+	for i in 0 .. data.len {
+		hash = (hash ^ u32(data[i])) * fnv32_prime
+	}
+	return hash
+}
+
+// sum32 returns a fnv1a hash of the memory block, described by the dynamic
+// byte array `data`.
+@[direct_array_access; inline]
+pub fn sum32(data []u8) u32 {
+	mut hash := fnv32_offset_basis
+	for i in 0 .. data.len {
+		hash = (hash ^ u32(data[i])) * fnv32_prime
+	}
+	return hash
+}
+
+// sum32_bytes returns a fnv1a hash of the struct `s`.
+@[direct_array_access; inline]
+pub fn sum32_struct[T](s &T) u32 {
+	bp := unsafe { &u8(s) }
+	sz := int(sizeof(T))
+	mut hash := fnv32_offset_basis
+	for i in 0 .. sz {
+		hash = unsafe { (hash ^ u32(bp[i])) * fnv32_prime }
+	}
+	return hash
+}
+
+// sum32_bytes returns a fnv1a hash of `data_len` bytes starting at
+// the address in the given &byte pointer `data`.
+@[direct_array_access; inline; unsafe]
+pub fn sum32_bytes(data &u8, data_len int) u32 {
+	mut hash := fnv32_offset_basis
+	for i in 0 .. data_len {
+		hash = unsafe { (hash ^ u32(data[i])) * fnv32_prime }
+	}
+	return hash
+}
+
+// sum64 returns a fnv1a hash of the string, described by `data`
+@[direct_array_access; inline]
+pub fn sum64_string(data string) u64 {
+	mut hash := fnv64_offset_basis
+	for i in 0 .. data.len {
+		hash = (hash ^ u64(data[i])) * fnv64_prime
+	}
+	return hash
+}
+
+// sum64 returns a fnv1a hash of the memory block, described by the dynamic
+// byte array `data`.
+@[direct_array_access; inline]
+pub fn sum64(data []u8) u64 {
+	mut hash := fnv64_offset_basis
+	for i in 0 .. data.len {
+		hash = (hash ^ u64(data[i])) * fnv64_prime
+	}
+	return hash
+}
+
+// sum64_bytes returns a fnv1a hash of `data_len` bytes starting at
+// the address in the given &byte pointer `data`.
+@[direct_array_access; inline; unsafe]
+pub fn sum64_bytes(data &u8, data_len int) u64 {
+	mut hash := fnv64_offset_basis
+	for i in 0 .. data_len {
+		hash = unsafe { (hash ^ u64(data[i])) * fnv64_prime }
+	}
+	return hash
+}
+
+// sum64_bytes returns a fnv1a hash of the struct `s`.
+@[direct_array_access; inline]
+pub fn sum64_struct[T](s &T) u64 {
+	bp := unsafe { &u8(s) }
+	sz := int(sizeof(T))
+	mut hash := fnv64_offset_basis
+	for i in 0 .. sz {
+		hash = unsafe { (hash ^ u64(bp[i])) * fnv64_prime }
+	}
+	return hash
+}