random ids

src/fragment_store/fragment_store.cpp

@@ -27,6 +27,21 @@ static const char* metaFileTypeSuffix(MetaFileType mft) {
 }
 
 FragmentStore::FragmentStore(void) {
+	{ // random namespace
+		const auto num0 = _rng();
+		const auto num1 = _rng();
+
+		_session_uuid_namespace[0] = (num0 >> 0) & 0xff;
+		_session_uuid_namespace[1] = (num0 >> 8) & 0xff;
+		_session_uuid_namespace[2] = (num0 >> 16) & 0xff;
+		_session_uuid_namespace[3] = (num0 >> 24) & 0xff;
+
+		_session_uuid_namespace[4] = (num1 >> 0) & 0xff;
+		_session_uuid_namespace[5] = (num1 >> 8) & 0xff;
+		_session_uuid_namespace[6] = (num1 >> 16) & 0xff;
+		_session_uuid_namespace[7] = (num1 >> 24) & 0xff;
+
+	}
 	registerSerializers();
 }
 
@@ -40,6 +55,30 @@ entt::basic_handle<entt::basic_registry<FragmentID>> FragmentStore::fragmentHand
 	return {_reg, fid};
 }
 
+std::vector<uint8_t> FragmentStore::generateNewUID(std::array<uint8_t, 8>& uuid_namespace) {
+	std::vector<uint8_t> new_uid(uuid_namespace.cbegin(), uuid_namespace.cend());
+	new_uid.resize(new_uid.size() + 8);
+
+	const auto num0 = _rng();
+	const auto num1 = _rng();
+
+	new_uid[uuid_namespace.size()+0] = (num0 >> 0) & 0xff;
+	new_uid[uuid_namespace.size()+1] = (num0 >> 8) & 0xff;
+	new_uid[uuid_namespace.size()+2] = (num0 >> 16) & 0xff;
+	new_uid[uuid_namespace.size()+3] = (num0 >> 24) & 0xff;
+
+	new_uid[uuid_namespace.size()+4] = (num1 >> 0) & 0xff;
+	new_uid[uuid_namespace.size()+5] = (num1 >> 8) & 0xff;
+	new_uid[uuid_namespace.size()+6] = (num1 >> 16) & 0xff;
+	new_uid[uuid_namespace.size()+7] = (num1 >> 24) & 0xff;
+
+	return new_uid;
+}
+
+std::vector<uint8_t> FragmentStore::generateNewUID(void) {
+	return generateNewUID(_session_uuid_namespace);
+}
+
 FragmentID FragmentStore::newFragmentMemoryOwned(
 	const std::vector<uint8_t>& id,
 	size_t initial_size
@@ -126,6 +165,12 @@ FragmentID FragmentStore::newFragmentFile(
 
 	return new_frag;
 }
+FragmentID FragmentStore::newFragmentFile(
+	std::string_view store_path,
+	MetaFileType mft
+) {
+	return newFragmentFile(store_path, mft, generateNewUID());
+}
 
 FragmentID FragmentStore::getFragmentByID(
 	const std::vector<uint8_t>& id

src/fragment_store/fragment_store.hpp

@@ -1,7 +1,6 @@
 #pragma once
 
 #include "./fragment_store_i.hpp"
-#include "entt/entity/fwd.hpp"
 
 #include <entt/core/fwd.hpp>
 #include <entt/core/type_info.hpp>
@@ -14,6 +13,7 @@
 #include <vector>
 #include <array>
 #include <cstdint>
+#include <random>
 
 enum class Encryption : uint8_t {
 	NONE = 0x00,
@@ -99,6 +99,7 @@ struct SerializerCallbacks {
 struct FragmentStore : public FragmentStoreI {
 	entt::basic_registry<FragmentID> _reg;
 
+	std::minstd_rand _rng{std::random_device{}()};
 	std::array<uint8_t, 8> _session_uuid_namespace;
 
 	std::string _default_store_path;
@@ -116,6 +117,9 @@ struct FragmentStore : public FragmentStoreI {
 
 	// TODO: make the frags ref counted
 
+	std::vector<uint8_t> generateNewUID(std::array<uint8_t, 8>& uuid_namespace);
+	std::vector<uint8_t> generateNewUID(void);
+
 	// ========== new fragment ==========
 
 	// memory backed owned

src/fragment_store/test_fragstore.cpp

@@ -36,7 +36,9 @@ int main(void) {
 
 	const auto frag0 = fs.newFragmentFile("", MetaFileType::TEXT_JSON, {0xff, 0xf1, 0xf2, 0xf0, 0xff, 0xff, 0xff, 0xf9});
 
-	const auto frag1 = fs.newFragmentFile("", MetaFileType::BINARY_MSGPACK, {0xff, 0xff, 0xf0, 0xf0, 0xf0, 0xf0, 0xff, 0xf9});
+	const auto frag1 = fs.newFragmentFile("", MetaFileType::BINARY_MSGPACK);
+
+	const auto frag2 = fs.newFragmentFile("", MetaFileType::BINARY_MSGPACK);
 
 	{
 		auto frag0h = fs.fragmentHandle(frag0);
@@ -62,7 +64,6 @@ int main(void) {
 
 		frag1h.emplace_or_replace<Components::DataCompressionType>();
 		frag1h.emplace_or_replace<Components::DataEncryptionType>();
-		//frag1h.emplace_or_replace<Components::Ephemeral::MetaFileType>(MetaFileType::BINARY_MSGPACK);
 
 		std::function<FragmentStore::write_to_storage_fetch_data_cb> fn_cb = [read = 0ul](uint8_t* request_buffer, uint64_t buffer_size) mutable -> uint64_t {
 			static constexpr std::string_view text = "This is some random data";