1 files changed, 75 insertions, 0 deletions
diff --git a/src/rocksdb/utilities/cassandra/serialize.h b/src/rocksdb/utilities/cassandra/serialize.h
new file mode 100644
index 00000000..64ccd4c2
--- /dev/null
+++ b/src/rocksdb/utilities/cassandra/serialize.h
@@ -0,0 +1,75 @@
+//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+/**
+ * Helper functions which serialize and deserialize integers
+ * into bytes in big endian.
+ */
+
+#pragma once
+
+namespace rocksdb {
+namespace cassandra {
+namespace {
+const int64_t kCharMask = 0xFFLL;
+const int32_t kBitsPerByte = 8;
+}
+
+template<typename T>
+void Serialize(T val, std::string* dest);
+
+template<typename T>
+T Deserialize(const char* src, std::size_t offset=0);
+
+// Specializations
+template<>
+inline void Serialize<int8_t>(int8_t t, std::string* dest) {
+  dest->append(1, static_cast<char>(t & kCharMask));
+}
+
+template<>
+inline void Serialize<int32_t>(int32_t t, std::string* dest) {
+  for (unsigned long i = 0; i < sizeof(int32_t); i++) {
+     dest->append(1, static_cast<char>(
+       (t >> (sizeof(int32_t) - 1 - i) * kBitsPerByte) & kCharMask));
+  }
+}
+
+template<>
+inline void Serialize<int64_t>(int64_t t, std::string* dest) {
+  for (unsigned long i = 0; i < sizeof(int64_t); i++) {
+     dest->append(
+       1, static_cast<char>(
+         (t >> (sizeof(int64_t) - 1 - i) * kBitsPerByte) & kCharMask));
+  }
+}
+
+template<>
+inline int8_t Deserialize<int8_t>(const char* src, std::size_t offset) {
+  return static_cast<int8_t>(src[offset]);
+}
+
+template<>
+inline int32_t Deserialize<int32_t>(const char* src, std::size_t offset) {
+  int32_t result = 0;
+  for (unsigned long i = 0; i < sizeof(int32_t); i++) {
+    result |= static_cast<int32_t>(static_cast<unsigned char>(src[offset + i]))
+        << ((sizeof(int32_t) - 1 - i) * kBitsPerByte);
+  }
+  return result;
+}
+
+template<>
+inline int64_t Deserialize<int64_t>(const char* src, std::size_t offset) {
+  int64_t result = 0;
+  for (unsigned long i = 0; i < sizeof(int64_t); i++) {
+    result |= static_cast<int64_t>(static_cast<unsigned char>(src[offset + i]))
+        << ((sizeof(int64_t) - 1 - i) * kBitsPerByte);
+  }
+  return result;
+}
+
+} // namepsace cassandrda
+} // namespace rocksdb