Adding zenservice code

1 files changed, 196 insertions, 0 deletions

diff --git a/zencore/uid.cpp b/zencore/uid.cpp
new file mode 100644
index 000000000..9506b305c
--- /dev/null
+++ b/zencore/uid.cpp
@@ -0,0 +1,196 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include <zencore/uid.h>
+
+#include <zencore/string.h>
+
+#if _WIN32
+#	include <zencore/windows.h>
+#	include <bcrypt.h>
+#	pragma comment(lib, "bcrypt.lib")
+#endif
+
+#include <atomic>
+#include <bit>
+#include <set>
+#include <unordered_map>
+
+#include <doctest/doctest.h>
+
+namespace zen {
+
+//////////////////////////////////////////////////////////////////////////
+
+template<typename T>
+T
+EndianSwap(T value)
+{
+	uint8_t dest[sizeof value];
+
+	memcpy(dest, &value, sizeof value);
+
+	for (int i = 0; i < sizeof(value); i++)
+	{
+		uint8_t& other = dest[sizeof(value) - i - 1];
+
+		uint8_t temp = dest[i];
+		dest[i]		 = other;
+		other		 = temp;
+	}
+
+	T ret;
+
+	memcpy(&ret, &value, sizeof value);
+
+	return ret;
+}
+
+#if _WIN32
+__forceinline uint16_t
+EndianSwap(uint16_t value)
+{
+	return _byteswap_ushort(value);
+}
+
+__forceinline uint32_t
+EndianSwap(uint32_t value)
+{
+	return _byteswap_ulong(value);
+}
+
+__forceinline uint64_t
+EndianSwap(uint64_t value)
+{
+	return _byteswap_uint64(value);
+}
+#endif
+
+//////////////////////////////////////////////////////////////////////////
+
+namespace detail {
+	static bool					OidInitialised;
+	static uint32_t				RunId;
+	static std::atomic_uint32_t Serial;
+
+	// Number of 100 nanosecond units from 1/1/1601 to 1/1/1970 - used for Windows impl
+	constexpr int64_t kEpochBias = 116'444'736'000'000'000ull;
+}  // namespace detail
+
+//////////////////////////////////////////////////////////////////////////
+
+const Oid Oid::Zero = {{0u, 0u, 0u}};
+const Oid Oid::Max	= {{~0u, ~0u, ~0u}};
+
+void
+Oid::Initialize()
+{
+	using namespace detail;
+
+	if (OidInitialised)
+		return;
+
+	OidInitialised = true;
+
+#if _WIN32
+	char rng[8];
+	BCryptGenRandom(NULL, (PUCHAR)rng, sizeof rng, BCRYPT_USE_SYSTEM_PREFERRED_RNG);
+
+	memcpy(&RunId, &rng[0], sizeof(RunId));
+	memcpy((void*)&Serial, &rng[4], sizeof(Serial));
+#else
+#	error Must implement Oid::Initialize
+#endif
+}
+
+const Oid&
+Oid::Generate()
+{
+	using namespace detail;
+
+	if (!OidInitialised)
+	{
+		Oid::Initialize();
+	}
+
+#if _WIN32
+	FILETIME filetime;
+
+	GetSystemTimeAsFileTime(&filetime);	 // Time is UTC
+
+	uint64_t filetime64;
+	memcpy(&filetime64, &filetime, sizeof filetime);
+
+	OidBits[0] = EndianSwap(uint32_t((filetime64 - kEpochBias) / 10'000'000l));
+	OidBits[1] = EndianSwap(uint32_t(Serial++));
+	OidBits[2] = RunId;
+#else
+#	error Must implement Oid::Generate
+#endif
+
+	return *this;
+}
+
+Oid
+Oid::NewOid()
+{
+	return Oid().Generate();
+}
+
+Oid
+Oid::FromHexString(const std::string_view String)
+{
+	ZEN_ASSERT(String.size() == 2 * sizeof(Oid::OidBits));
+
+	Oid Id;
+
+	ParseHexBytes(String.data(), String.size(), reinterpret_cast<uint8_t*>(Id.OidBits));
+
+	return Id;
+}
+
+StringBuilderBase&
+Oid::ToString(StringBuilderBase& OutString) const
+{
+	char str[25];
+	ToHexBytes(reinterpret_cast<const uint8_t*>(OidBits), sizeof(Oid::OidBits), str);
+	str[2 * sizeof(Oid)] = '\0';
+
+	OutString.AppendRange(str, &str[25]);
+
+	return OutString;
+}
+
+TEST_CASE("Oid")
+{
+	SUBCASE("Basic")
+	{
+		Oid id1 = Oid::NewOid();
+
+		std::vector<Oid>						  ids;
+		std::set<Oid>							  idset;
+		std::unordered_map<Oid, int, Oid::Hasher> idmap;
+
+		const int Count = 1000;
+
+		for (int i = 0; i < Count; ++i)
+		{
+			Oid id;
+			id.Generate();
+
+			ids.emplace_back(id);
+			idset.insert(id);
+			idmap.insert({id, i});
+		}
+
+		CHECK(ids.size() == Count);
+		CHECK(idset.size() == Count);  // All ids should be unique
+		CHECK(idmap.size() == Count);  // Ditto
+	}
+}
+
+void
+uid_forcelink()
+{
+}
+
+}  // namespace zen