From fcb214064030d81279bd1b7f756c3f2216045afb Mon Sep 17 00:00:00 2001
From: Emiel Por <epor@stsci.edu>
Date: Mon, 16 Dec 2024 17:02:30 -0800
Subject: [PATCH] Add UUID generator based on two MT19937 pseudo-random number
 generators seeded by true randomness.

---
 benchmarks/uuid_generator.cpp | 32 ++++++++++++++++++++++++++++++++
 catkit_core/CMakeLists.txt    |  1 +
 catkit_core/UuidGenerator.cpp | 21 +++++++++++++++++++++
 catkit_core/UuidGenerator.h   | 17 +++++++++++++++++
 4 files changed, 71 insertions(+)
 create mode 100644 benchmarks/uuid_generator.cpp
 create mode 100644 catkit_core/UuidGenerator.cpp
 create mode 100644 catkit_core/UuidGenerator.h

diff --git a/benchmarks/uuid_generator.cpp b/benchmarks/uuid_generator.cpp
new file mode 100644
index 00000000..bb2879cf
--- /dev/null
+++ b/benchmarks/uuid_generator.cpp
@@ -0,0 +1,32 @@
+#include "UuidGenerator.h"
+#include "Timing.h"
+
+#include <iostream>
+
+int main()
+{
+	const size_t N = 100000000;
+
+	UuidGenerator generator;
+
+	char uuid[16];
+
+	std::cout << std::hex;
+
+	auto start = GetTimeStamp();
+
+	for (size_t i = 0; i < N; ++i)
+	{
+		generator.GenerateUuid(uuid);
+	}
+
+	auto end = GetTimeStamp();
+
+	std::cout << std::dec;
+
+	std::cout << "Time: " << (end - start) / 1e9 << " sec" << std::endl;
+	std::cout << "Throughput: " << N / ((end - start) / 1e9) << " ops/s" << std::endl;
+	std::cout << "Time per operation: " << (end - start) / N << " ns" << std::endl;
+
+	return 0;
+}
diff --git a/catkit_core/CMakeLists.txt b/catkit_core/CMakeLists.txt
index 6258d432..360db308 100644
--- a/catkit_core/CMakeLists.txt
+++ b/catkit_core/CMakeLists.txt
@@ -35,6 +35,7 @@ add_library(catkit_core STATIC
     Util.cpp
     PoolAllocator.cpp
     FreeListAllocator.cpp
+    UuidGenerator.cpp
     proto/core.pb.cc
     proto/logging.pb.cc
     proto/testbed.pb.cc
diff --git a/catkit_core/UuidGenerator.cpp b/catkit_core/UuidGenerator.cpp
new file mode 100644
index 00000000..ea68bcaf
--- /dev/null
+++ b/catkit_core/UuidGenerator.cpp
@@ -0,0 +1,21 @@
+#include "UuidGenerator.h"
+
+UuidGenerator::UuidGenerator()
+{
+	std::random_device random_device;
+
+	for (size_t i = 0; i < 2; ++i)
+	{
+		std::seed_seq seed{random_device(), random_device()};
+		m_Engines[i].seed(seed);
+	}
+}
+
+void UuidGenerator::GenerateUuid(char *uuid)
+{
+	for (size_t i = 0; i < 2; ++i)
+	{
+		std::uint64_t value = m_Engines[i]();
+		*reinterpret_cast<std::uint64_t *>(uuid + i * 8) = value;
+	}
+}
diff --git a/catkit_core/UuidGenerator.h b/catkit_core/UuidGenerator.h
new file mode 100644
index 00000000..244b828d
--- /dev/null
+++ b/catkit_core/UuidGenerator.h
@@ -0,0 +1,17 @@
+#ifndef UUID_GENERATOR_H
+#define UUID_GENERATOR_H
+
+#include <random>
+
+class UuidGenerator
+{
+public:
+	UuidGenerator();
+
+	void GenerateUuid(char *uuid);
+
+private:
+	std::mt19937_64 m_Engines[2];
+};
+
+#endif // UUID_GENERATOR_H