From 816760c8480e8e76c7f4021a845161eb697e215c Mon Sep 17 00:00:00 2001
From: Claudius 'keldu' Holeksa <mail@keldu.de>
Date: Mon, 15 Jul 2024 15:29:12 +0200
Subject: Moving remote definitions from codec to remote module

---
 modules/remote/c++/remote.hpp               | 116 +++++++++++++++++++++
 modules/remote/c++/remote_loopback.hpp      |  99 ++++++++++++++++++
 modules/remote/c++/remote_loopback_base.hpp |   7 ++
 modules/remote/c++/transfer.hpp             |  21 ++++
 modules/remote/c++/transfer_loopback.hpp    | 152 ++++++++++++++++++++++++++++
 5 files changed, 395 insertions(+)
 create mode 100644 modules/remote/c++/remote.hpp
 create mode 100644 modules/remote/c++/remote_loopback.hpp
 create mode 100644 modules/remote/c++/remote_loopback_base.hpp
 create mode 100644 modules/remote/c++/transfer.hpp
 create mode 100644 modules/remote/c++/transfer_loopback.hpp

(limited to 'modules/remote')

diff --git a/modules/remote/c++/remote.hpp b/modules/remote/c++/remote.hpp
new file mode 100644
index 0000000..5803154
--- /dev/null
+++ b/modules/remote/c++/remote.hpp
@@ -0,0 +1,116 @@
+#pragma once
+
+#include <forstio/id.hpp>
+#include <forstio/async/async.hpp>
+
+#include "data.hpp"
+#include "interface.hpp"
+
+#include <variant>
+
+namespace saw {
+/**
+ * This class acts as a helper for rpc calls and representing data on the remote.
+ */
+template<typename T, typename Encoding, typename Storage>
+class data_or_id {
+private:
+	/**
+	 * Variant representing the either id or data class.
+	 */
+	std::variant<id<T>, data<T,Encoding, Storage>> doi_;
+public:
+	/**
+	 * Constructor for instantiating.
+	 */
+	data_or_id(const id<T>& val):
+		doi_{val}
+	{}
+
+	/**
+	 * Constructor for instantiating.
+	 */
+	data_or_id(data<T,Encoding, Storage> val):
+		doi_{std::move(val)}
+	{}
+
+	/**
+	 * Check if this class holds an id.
+	 */
+	bool is_id() const {
+		return std::holds_alternative<id<T>>(doi_);
+	}
+
+	/**
+	 * Check if this class holds data.
+	 */
+	bool is_data() const {
+		return std::holds_alternative<data<T,Encoding,Storage>>(doi_);
+	}
+
+	/**
+	 * Returns the id.
+	 */
+	id<T> get_id() const {
+		return std::get<id<T>>(doi_);
+	}
+
+	/**
+	 * Return a data reference.
+	 */
+	data<T,Encoding, Storage>& get_data(){
+		return std::get<data<T,Encoding, Storage>>(doi_);
+	}
+
+	/**
+	 * Return a data reference.
+	 */
+	const data<T,Encoding,Storage>& get_data() const {
+		return std::get<data<T,Encoding,Storage>>(doi_);
+	}
+};
+
+
+/**
+ * Representing data on the remote
+ */
+template<typename T, typename Encoding, typename Storage, typename Remote>
+class remote_data;
+
+template<typename Iface, typename Encoding, typename Storage, typename Remote>
+class rpc_client;
+
+/**
+ * Implementation of a remote server on the backend
+ */
+template<typename Iface, typename Encoding, typename Storage, typename Remote>
+class rpc_server {
+private:
+	interface<Iface, Encoding, Storage> iface_;
+public:
+	rpc_server(interface<Iface, Encoding, Storage> iface):
+		iface_{std::move(iface)}
+	{}
+};
+
+/**
+ * Representation of a remote.
+ * Partially similar to a network address
+ */
+template<typename Remote>
+class remote_address {
+	static_assert(always_false<Remote>, "Type of remote not supported");
+
+	/**
+	 *
+	 */
+};
+
+/**
+ * Reference Backend structure
+ */
+template<typename Remote>
+class remote {
+	static_assert(always_false<Remote>, "Type of backend not supported");
+};
+}
diff --git a/modules/remote/c++/remote_loopback.hpp b/modules/remote/c++/remote_loopback.hpp
new file mode 100644
index 0000000..2949243
--- /dev/null
+++ b/modules/remote/c++/remote_loopback.hpp
@@ -0,0 +1,99 @@
+#pragma once
+
+#include <variant>
+
+#include "interface.hpp"
+#include "remote.hpp"
+#include "transfer_loopback.hpp"
+
+namespace saw {
+
+template<typename T, typename Encoding, typename Storage>
+class remote_data<T, Encoding, Storage, rmt::Loopback> {
+private:
+	id<T> id_;
+public:
+	remote_data(const id<T>& id):
+		id_{id}
+	{}
+
+	/**
+	 * Wait until data arrives
+	 */
+	error_or<data<T, Encoding, Storage>> wait(wait_scope& wait);
+
+	/**
+	 * Asynchronously wait for a result
+	 */
+	conveyor<data<T, Encoding, Storage>> on_receive();
+};
+
+/**
+ * Client RPC reference structure
+ */
+template<typename Iface, typename Encoding, typename Storage>
+class rpc_client<Iface, Encoding, Storage, rmt::Loopback> {
+	/**
+	 * request the data from the remote
+	 */
+	template<typename IdT>
+	remote_data<IdT, Encoding, Storage, rmt::Loopback> request_data(id<IdT> data);
+		
+	/** @todo
+	 * Determine type based on Name
+	 */
+	/*
+	template<string_literal Name>
+	error_or<
+		id<
+			typename schema_member_type<Name, Iface>::type
+		>
+	> call(data_or_id<Input> inp);
+	*/
+};
+
+template<>
+class remote_address<rmt::Loopback> {
+};
+
+template<typename Iface, typename Encode, typename Storage>
+class rpc_server<Iface, Encode, Storage, rmt::Loopback> {
+public:
+	using InterfaceT = interface<Iface, Encode, Storage>;
+private:
+	const remote_address<rmt::Loopback>* addr_;
+	InterfaceT iface_;
+public:
+	rpc_server(const remote_address<rmt::Loopback>& addr__, InterfaceT iface__):
+		addr_{&addr__},
+		iface_{std::move(iface__)}
+	{}
+
+	// error_or<id<>>
+};
+
+template<>
+class remote<rmt::Loopback> {
+public:
+	/**
+	 * Resolves an address for the remote
+	 */
+	error_or<own<remote_address<rmt::Loopback>>> parse_address(){
+		return heap<remote_address<rmt::Loopback>>();
+	}
+
+	/**
+	 * Connect to a remote
+	 */
+	template<typename Iface, typename Encode, typename Storage>
+	conveyor<rpc_client<Iface, Encode, Storage, rmt::Loopback>> connect(const remote_address<rmt::Loopback>& addr);
+
+	/**
+	 * Start listening
+	 */
+	template<typename Iface, typename Encode, typename Storage>
+	rpc_server<Iface, Encode, Storage, rmt::Loopback> listen(const remote_address<rmt::Loopback>& addr, typename rpc_server<Iface,Encode,Storage,rmt::Loopback>::InterfaceT iface){
+		return {addr, std::move(iface)};
+	}
+};
+}
diff --git a/modules/remote/c++/remote_loopback_base.hpp b/modules/remote/c++/remote_loopback_base.hpp
new file mode 100644
index 0000000..823c516
--- /dev/null
+++ b/modules/remote/c++/remote_loopback_base.hpp
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace saw {
+namespace rmt {
+struct Loopback {};
+}
+}
diff --git a/modules/remote/c++/transfer.hpp b/modules/remote/c++/transfer.hpp
new file mode 100644
index 0000000..2fdd0b9
--- /dev/null
+++ b/modules/remote/c++/transfer.hpp
@@ -0,0 +1,21 @@
+#pragma once
+
+namespace saw {
+template<typename Schema, typename Encoding, typename Remote>
+class data_server;
+
+template<typename Schema, typename Encoding, typename Remote>
+class data_client;
+
+namespace impl {
+template<typename Encoding, typename Storage, typename T>
+struct data_server_redux {
+	using type = std::tuple<>;
+};
+
+template<typename Encoding, typename Storage, typename... Schema>
+struct data_server_redux<Encoding, Storage, tmpl_group<Schema...>> {
+	using type = std::tuple<std::unordered_map<uint64_t, data<Schema, Encoding, Storage>>...>;
+};
+}
+}
diff --git a/modules/remote/c++/transfer_loopback.hpp b/modules/remote/c++/transfer_loopback.hpp
new file mode 100644
index 0000000..6c81c9c
--- /dev/null
+++ b/modules/remote/c++/transfer_loopback.hpp
@@ -0,0 +1,152 @@
+#pragma once
+
+#include <forstio/reduce_templates.hpp>
+
+#include "transfer.hpp"
+
+namespace saw {
+namespace rmt {
+struct Loopback {};
+}
+
+template<typename... Schema, typename Encoding>
+class data_server<tmpl_group<Schema...>, Encoding, rmt::Loopback> {
+private:
+	typename impl::data_server_redux<Encoding, storage::Default, typename tmpl_reduce<tmpl_group<Schema...>>::type>::type values_;
+public:
+	/**
+	 * Get data from client
+	 */
+	template<typename Sch>
+	error_or<void> send(const data<Sch, Encoding, storage::Default>& dat, id<Sch> store_id){
+		auto& vals = std::get<std::unordered_map<uint64_t, data<Sch,Encoding>>>(values_);
+
+		try {
+			auto insert_res = vals.emplace(std::make_pair(store_id.get_value(), std::move(dat)));
+			if(!insert_res.second){
+				return make_error<err::already_exists>();
+			}
+		}catch(std::exception& ){
+			return make_error<err::out_of_memory>();
+		}
+		return void_t{};
+	}
+
+	template<typename Sch>
+	error_or<data<Sch, Encoding, storage::Default>> receive(id<Sch> store_id){
+		auto& vals = std::get<std::unordered_map<uint64_t, data<Sch,Encoding>>>(values_);
+
+		auto find_res = vals.find(store_id.get_value());
+		if(find_res == vals.end()){
+			return make_error<err::not_found>();
+		}
+
+		auto& dat = find_res->second;
+		return dat;
+	}
+
+	template<typename Sch>
+	error_or<void> erase(id<Sch> store_id){
+		auto& vals = std::get<std::unordered_map<uint64_t, data<Sch,Encoding>>>(values_);
+		auto erase_op = vals.erase(store_id.get_value());
+		if(erase_op == 0u){
+			return make_error<err::not_found>();
+		}
+		return void_t{};
+	}
+
+	template<typename Sch>
+	error_or<data<Sch, Encoding, storage::Default>*> find(id<Sch> store_id){
+		auto& vals = std::get<std::unordered_map<uint64_t, data<Sch,Encoding>>>(values_);
+		auto find_res = vals.find(store_id.get_value());
+		if(find_res == vals.end()){
+			return make_error<err::not_found>();
+		}
+
+		auto& dat = find_res->second;
+		return &dat;
+	}
+};
+
+/**
+ * Client for transporting data to remote and receiving data back
+ */
+template<typename... Schema, typename Encoding>
+class data_client<tmpl_group<Schema...>, Encoding, rmt::Loopback> {
+private:
+	/**
+	 * Corresponding server for this client
+	 */
+	data_server<tmpl_group<Schema...>, Encoding, rmt::Loopback>* srv_;
+
+	/**
+	 * The next id for identifying issues on the remote side.
+	 */
+	uint64_t next_id_;
+public:
+	/**
+	 * Main constructor
+	 */
+	data_client(data_server<tmpl_group<Schema...>, Encoding, rmt::Loopback>& srv__):
+		srv_{&srv__},
+		next_id_{0u}
+	{}
+
+	/**
+	 * Send data to the remote.
+	 */
+	template<typename Sch>
+	error_or<id<Sch>> send(const data<Sch, Encoding, storage::Default>& dat){
+		id<Sch> dat_id{next_id_};
+		auto eov = srv_->send(dat, dat_id);
+		if(eov.is_error()){
+			auto& err = eov.get_error();
+			return std::move(err);
+		}
+
+		++next_id_;
+		return dat_id;
+	}
+
+	/**
+	 * Receive data
+	 */
+	template<typename Sch>
+	conveyor<data<Sch, Encoding, storage::Default>> receive(id<Sch> dat_id){
+		auto eov = srv_->receive(dat_id);
+		if(eov.is_error()){
+			auto& err = eov.get_error();
+			return std::move(err);
+		}
+
+		auto& val = eov.get_value();
+		return std::move(val);
+	}
+
+	/**
+	 * Erase data
+	 */
+	template<typename Sch>
+	error_or<void> erase(id<Sch> dat_id){
+		return srv_->erase(dat_id);
+	}
+
+	/**
+	 * An exception for the Loopback backend. Here we can safely use find from
+	 * the client side.
+	 */
+	template<typename Sch>
+	error_or<data<Sch, Encoding>*> find(id<Sch> dat_id){
+		auto eov = srv_->find(dat_id);
+		if(eov.is_error()){
+			auto& err = eov.get_error();
+			return std::move(err);
+		}
+
+		auto val = eov.get_value();
+		return val;
+	}
+
+};
+
+}
-- 
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