loading fragments mostly working (not notifying anyone yet)

src/fragment_store/fragment_store.cpp

@@ -3,6 +3,8 @@
 #include <solanaceae/util/utils.hpp>
 
 #include <entt/entity/handle.hpp>
+#include <entt/container/dense_set.hpp>
+#include <entt/core/hashed_string.hpp>
 
 #include <nlohmann/json.hpp>
 
@@ -13,6 +15,7 @@
 #include <mutex>
 #include <type_traits>
 #include <utility>
+#include <algorithm>
 
 #include <iostream>
 #include <vector>
@@ -51,7 +54,7 @@ FragmentStore::FragmentStore(
 	registerSerializers();
 }
 
-FragmentStore::FragmentHandle FragmentStore::fragmentHandle(FragmentID fid) {
+FragmentHandle FragmentStore::fragmentHandle(FragmentID fid) {
 	return {_reg, fid};
 }
 
@@ -340,6 +343,184 @@ bool FragmentStore::syncToStorage(FragmentID fid, const uint8_t* data, const uin
 	return syncToStorage(fid, fn_cb);
 }
 
+size_t FragmentStore::scanStoragePath(std::string_view path) {
+	if (path.empty()) {
+		path = _default_store_path;
+	}
+	// TODO: extract so async can work (or/and make iteratable generator)
+
+	if (!std::filesystem::is_directory(path)) {
+		std::cerr << "FS error: scan path not a directory '" << path << "'\n";
+		return 0;
+	}
+
+	// step 1: make snapshot of files, validate metafiles and save id/path+meta.ext
+	// can be extra thread (if non vfs)
+	struct FragFileEntry {
+		std::string id_str;
+		std::filesystem::path frag_path;
+		std::string meta_ext;
+
+		bool operator==(const FragFileEntry& other) const {
+			// only compare by id
+			return id_str == other.id_str;
+		}
+	};
+	struct FragFileEntryHash {
+		size_t operator()(const FragFileEntry& it) const {
+			return entt::hashed_string(it.id_str.data(), it.id_str.size());
+		}
+	};
+	entt::dense_set<FragFileEntry, FragFileEntryHash> file_frag_list;
+
+	std::filesystem::path storage_path{path};
+
+	auto handle_file = [&](const std::filesystem::path& file_path) {
+		if (!std::filesystem::is_regular_file(file_path)) {
+			return;
+		}
+		// handle file
+
+		if (file_path.has_extension()) {
+			// skip over metadata, assuming only metafiles have extentions (might be wrong?)
+			// also skips temps
+			return;
+		}
+
+		auto relative_path = std::filesystem::proximate(file_path, storage_path);
+		std::string id_str = relative_path.generic_u8string();
+		// delete all '/'
+		id_str.erase(std::remove(id_str.begin(), id_str.end(), '/'), id_str.end());
+		if (id_str.size() % 2 != 0) {
+			std::cerr << "FS error: non hex fragment uid detected: '" << id_str << "'\n";
+		}
+
+		if (file_frag_list.contains(FragFileEntry{id_str, {}, ""})) {
+			std::cerr << "FS error: fragment duplicate detected: '" << id_str << "'\n";
+			return; // skip
+		}
+
+		const char* meta_ext = ".meta.msgpack";
+		{ // find meta
+			// TODO: this as to know all possible extentions
+			bool has_meta_msgpack = std::filesystem::is_regular_file(file_path.generic_u8string() + ".meta.msgpack");
+			bool has_meta_json = std::filesystem::is_regular_file(file_path.generic_u8string() + ".meta.json");
+			const size_t meta_sum =
+				(has_meta_msgpack?1:0) +
+				(has_meta_json?1:0)
+			;
+
+			if (meta_sum > 1) { // has multiple
+				std::cerr << "FS error: fragment with multiple meta files detected: " << id_str << "\n";
+				return; // skip
+			}
+
+			if (meta_sum == 0) {
+				std::cerr << "FS error: fragment missing meta file detected: " << id_str << "\n";
+				return; // skip
+			}
+
+			if (has_meta_json) {
+				meta_ext = ".meta.json";
+			}
+		}
+
+		file_frag_list.emplace(FragFileEntry{
+			std::move(id_str),
+			file_path,
+			meta_ext
+		});
+	};
+
+	for (const auto& outer_path : std::filesystem::directory_iterator(storage_path)) {
+		if (std::filesystem::is_regular_file(outer_path)) {
+			handle_file(outer_path);
+		} else if (std::filesystem::is_directory(outer_path)) {
+			// subdir, part of id
+			for (const auto& inner_path : std::filesystem::directory_iterator(outer_path)) {
+				//if (std::filesystem::is_regular_file(inner_path)) {
+
+					//// handle file
+				//} // TODO: support deeper recursion?
+				handle_file(inner_path);
+			}
+		}
+	}
+
+	std::cout << "FS: scan found:\n";
+	for (const auto& it : file_frag_list) {
+		std::cout << "  " << it.id_str << "\n";
+	}
+
+	// step 2: check if files preexist in reg
+	// main thread
+	// (merge into step 3 and do more error checking?)
+	for (auto it = file_frag_list.begin(); it != file_frag_list.end();) {
+		auto id = hex2bin(it->id_str);
+		auto fid = getFragmentByID(id);
+		if (_reg.valid(fid)) {
+			// pre exising (handle differently??)
+			// check if store differs?
+			it = file_frag_list.erase(it);
+		} else {
+			it++;
+		}
+	}
+
+	size_t count {0};
+	// step 3: parse meta and insert into reg of non preexising
+	// main thread
+	// TODO: check timestamps of preexisting and reload? mark external/remote dirty?
+	for (const auto& it : file_frag_list) {
+		nlohmann::json j;
+		if (it.meta_ext == ".meta.msgpack") {
+			// uh
+			// read binary header
+		} else if (it.meta_ext == ".meta.json") {
+			std::ifstream file(it.frag_path.generic_u8string() + it.meta_ext);
+			if (!file.is_open()) {
+				std::cout << "FS error: failed opening meta " << it.frag_path << "\n";
+				continue;
+			}
+
+			file >> j;
+
+			if (!j.is_object()) {
+				std::cerr << "FS error: json in meta is broken " << it.id_str << "\n";
+				continue;
+			}
+
+			// TODO: existing fragment file
+			//newFragmentFile();
+			FragmentHandle fh{_reg, _reg.create()};
+			fh.emplace<FragComp::ID>(hex2bin(it.id_str));
+
+			for (const auto& [k, v] : j.items()) {
+				// type id from string hash
+				const auto type_id = entt::hashed_string(k.data(), k.size());
+				const auto deserl_fn_it = _sc._deserl_json.find(type_id);
+				if (deserl_fn_it != _sc._deserl_json.cend()) {
+					// TODO: check return value
+					deserl_fn_it->second(fh, v);
+				} else {
+					std::cerr << "FS warning: missing deserializer for meta key '" << k << "'\n";
+				}
+			}
+			count++;
+		} else {
+			assert(false);
+		}
+	}
+
+	return count;
+}
+
+void FragmentStore::scanStoragePathAsync(std::string path) {
+	// add path to queue
+	// HACK: if path is known/any fragment is in the path, this operation blocks (non async)
+	scanStoragePath(path); // TODO: make async and post result
+}
+
 static bool serl_json_data_enc_type(void* comp, nlohmann::json& out) {
 	if (comp == nullptr) {
 		return false;
@@ -352,6 +533,20 @@ static bool serl_json_data_enc_type(void* comp, nlohmann::json& out) {
 	return true;
 }
 
+static bool deserl_json_data_enc_type(FragmentHandle fh, const nlohmann::json& in) {
+	// TODO: this is ugly in multiple places
+	try {
+		fh.emplace_or_replace<FragComp::DataEncryptionType>(
+			static_cast<Encryption>(
+				static_cast<std::underlying_type_t<Encryption>>(in)
+			)
+		);
+	} catch(...) {
+		return false;
+	}
+	return true;
+}
+
 static bool serl_json_data_comp_type(void* comp, nlohmann::json& out) {
 	if (comp == nullptr) {
 		return false;
@@ -366,6 +561,7 @@ static bool serl_json_data_comp_type(void* comp, nlohmann::json& out) {
 
 void FragmentStore::registerSerializers(void) {
 	_sc.registerSerializerJson<FragComp::DataEncryptionType>(serl_json_data_enc_type);
+	_sc.registerDeSerializerJson<FragComp::DataEncryptionType>(deserl_json_data_enc_type);
 	_sc.registerSerializerJson<FragComp::DataCompressionType>(serl_json_data_comp_type);
 
 	std::cout << "registered serl text json cbs:\n";