3 files changed, 80 insertions, 0 deletions

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 1e8e1b215..cb514a0d2 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -123,6 +123,8 @@ add_library(common STATIC
     timer.h
     uint128.cpp
     uint128.h
+    uuid.cpp
+    uuid.h
     vector_math.h
     web_result.h
     zstd_compression.cpp
diff --git a/src/common/uuid.cpp b/src/common/uuid.cpp
new file mode 100644
index 000000000..8e63b58b8
--- /dev/null
+++ b/src/common/uuid.cpp
@@ -0,0 +1,33 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <random>
+
+#include <fmt/format.h>
+
+#include "common/uuid.h"
+
+namespace Common {
+
+UUID UUID::Generate() {
+    std::random_device device;
+    std::mt19937 gen(device());
+    std::uniform_int_distribution<u64> distribution(1, std::numeric_limits<u64>::max());
+    return UUID{distribution(gen), distribution(gen)};
+}
+
+std::string UUID::Format() const {
+    return fmt::format("0x{:016X}{:016X}", uuid[1], uuid[0]);
+}
+
+std::string UUID::FormatSwitch() const {
+    std::array<u8, 16> s{};
+    std::memcpy(s.data(), uuid.data(), sizeof(u128));
+    return fmt::format("{:02x}{:02x}{:02x}{:02x}-{:02x}{:02x}-{:02x}{:02x}-{:02x}{:02x}-{:02x}{"
+                       ":02x}{:02x}{:02x}{:02x}{:02x}",
+                       s[0], s[1], s[2], s[3], s[4], s[5], s[6], s[7], s[8], s[9], s[10], s[11],
+                       s[12], s[13], s[14], s[15]);
+}
+
+} // namespace Common
diff --git a/src/common/uuid.h b/src/common/uuid.h
new file mode 100644
index 000000000..4a5e5fa7c
--- /dev/null
+++ b/src/common/uuid.h
@@ -0,0 +1,45 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/common_types.h"
+
+namespace Common {
+
+constexpr u128 INVALID_UUID{{0, 0}};
+
+struct UUID {
+    // UUIDs which are 0 are considered invalid!
+    u128 uuid = INVALID_UUID;
+    constexpr UUID() = default;
+    constexpr explicit UUID(const u128& id) : uuid{id} {}
+    constexpr explicit UUID(const u64 lo, const u64 hi) : uuid{{lo, hi}} {}
+
+    explicit operator bool() const {
+        return uuid != INVALID_UUID;
+    }
+
+    bool operator==(const UUID& rhs) const {
+        return uuid == rhs.uuid;
+    }
+
+    bool operator!=(const UUID& rhs) const {
+        return !operator==(rhs);
+    }
+
+    // TODO(ogniK): Properly generate uuids based on RFC-4122
+    static UUID Generate();
+
+    // Set the UUID to {0,0} to be considered an invalid user
+    void Invalidate() {
+        uuid = INVALID_UUID;
+    }
+
+    std::string Format() const;
+    std::string FormatSwitch() const;
+};
+static_assert(sizeof(UUID) == 16, "UUID is an invalid size!");
+
+} // namespace Common