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-rwxr-xr-xlibtransport/src/hicn/transport/utils/hash.h101
1 files changed, 101 insertions, 0 deletions
diff --git a/libtransport/src/hicn/transport/utils/hash.h b/libtransport/src/hicn/transport/utils/hash.h
new file mode 100755
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+++ b/libtransport/src/hicn/transport/utils/hash.h
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+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Copyright 2017 Facebook, Inc.
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <hicn/transport/portability/portability.h>
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <string>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+
+namespace utils {
+
+namespace hash {
+
+/*
+ * Fowler / Noll / Vo (FNV) Hash
+ * http://www.isthe.com/chongo/tech/comp/fnv/
+ */
+
+const uint32_t FNV_32_HASH_START = 2166136261UL;
+const uint64_t FNV_64_HASH_START = 14695981039346656037ULL;
+
+TRANSPORT_ALWAYS_INLINE uint32_t fnv32(const char *s,
+ uint32_t hash = FNV_32_HASH_START) {
+ for (; *s; ++s) {
+ hash +=
+ (hash << 1) + (hash << 4) + (hash << 7) + (hash << 8) + (hash << 24);
+ hash ^= *s;
+ }
+ return hash;
+}
+
+TRANSPORT_ALWAYS_INLINE uint32_t fnv32_buf(const void *buf, size_t n,
+ uint32_t hash = FNV_32_HASH_START) {
+ // forcing signed char, since other platforms can use unsigned
+ const signed char *char_buf = reinterpret_cast<const signed char *>(buf);
+
+ for (size_t i = 0; i < n; ++i) {
+ hash +=
+ (hash << 1) + (hash << 4) + (hash << 7) + (hash << 8) + (hash << 24);
+ hash ^= char_buf[i];
+ }
+
+ return hash;
+}
+
+TRANSPORT_ALWAYS_INLINE uint32_t fnv32(const std::string &str,
+ uint32_t hash = FNV_32_HASH_START) {
+ return fnv32_buf(str.data(), str.size(), hash);
+}
+
+TRANSPORT_ALWAYS_INLINE uint64_t fnv64(const char *s,
+ uint64_t hash = FNV_64_HASH_START) {
+ for (; *s; ++s) {
+ hash += (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) +
+ (hash << 8) + (hash << 40);
+ hash ^= *s;
+ }
+ return hash;
+}
+
+TRANSPORT_ALWAYS_INLINE uint64_t fnv64_buf(const void *buf, size_t n,
+ uint64_t hash = FNV_64_HASH_START) {
+ // forcing signed char, since other platforms can use unsigned
+ const signed char *char_buf = reinterpret_cast<const signed char *>(buf);
+
+ for (size_t i = 0; i < n; ++i) {
+ hash += (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) +
+ (hash << 8) + (hash << 40);
+ hash ^= char_buf[i];
+ }
+ return hash;
+}
+
+TRANSPORT_ALWAYS_INLINE uint64_t fnv64(const std::string &str,
+ uint64_t hash = FNV_64_HASH_START) {
+ return fnv64_buf(str.data(), str.size(), hash);
+}
+
+} // namespace hash
+
+} // namespace utils