looper/rpc.hpp

#pragma once
#include <algorithm>
#include <any>
#include <grpcpp/security/server_credentials.h>
#include <grpcpp/server_builder.h>
#include <grpcpp/support/byte_buffer.h>
#include <grpc/grpc.h>
#include <grpc/support/port_platform.h>
#include <json/json.h>
#include <chrono>
#include <google/protobuf/descriptor.h>
#include <google/protobuf/generated_message_reflection.h>
#include <google/protobuf/message.h>
#include <memory>
#include <type_traits>
#include <cstdarg>
#include <stdint.h>
#include <stdlib.h>
#include "thirdparty/CRC.hpp"
#include <string>
#include <functional>
#include <thread>
#include <type_traits>
#include <vector>
#include <optional>
#include <thread>
#include <atomic>
#include <mutex>
#include <string.h>
#include <map>
#include <grpc++/grpc++.h>
#include <grpc++/server.h>
#include <variant>
#include <filesystem>
#include "log.hpp"
using namespace std::literals;
#define _FORMAT_CPP_TYPE(fdesc, value, prefix, int32, int64, uint32, uint64, float, double, bool, string, enum, message, ...) \
switch (fdesc->cpp_type()) { \
    case google::protobuf::FieldDescriptor::CPPTYPE_BOOL: \
        value = prefix##bool(__VA_ARGS__) ? "true" : "false"; \
        break; \
    case google::protobuf::FieldDescriptor::CPPTYPE_DOUBLE: \
        value = fmt::format("{0}", prefix##double(__VA_ARGS__)); \
        break; \
    case google::protobuf::FieldDescriptor::CPPTYPE_FLOAT: \
        value = fmt::format("{0}", prefix##float(__VA_ARGS__)); \
        break; \
    case google::protobuf::FieldDescriptor::CPPTYPE_INT32: \
        value = fmt::format("{0}", prefix##int32(__VA_ARGS__)); \
        break; \
    case google::protobuf::FieldDescriptor::CPPTYPE_UINT32: \
        value = fmt::format("{0}", prefix##uint32(__VA_ARGS__)); \
        break; \
    case google::protobuf::FieldDescriptor::CPPTYPE_INT64: \
        value = fmt::format("{0}", prefix##int64(__VA_ARGS__)); \
        break; \
    case google::protobuf::FieldDescriptor::CPPTYPE_UINT64: \
        value = fmt::format("{0}", prefix##uint64(__VA_ARGS__)); \
        break; \
    case google::protobuf::FieldDescriptor::CPPTYPE_STRING: \
        value = prefix##string(__VA_ARGS__); \
        break; \
    case google::protobuf::FieldDescriptor::CPPTYPE_ENUM: {\
        const auto *enum_desc = prefix##enum(__VA_ARGS__); \
        value = fmt::format("{0} = {1}", enum_desc->full_name(), enum_desc->index()); \
    } break; \
    case google::protobuf::FieldDescriptor::CPPTYPE_MESSAGE: \
        value = "(Message)"; \
        break; \
}

#define FORMAT_CPP_TYPE_LOWERCASE(fdesc, value, prefix, ...) _FORMAT_CPP_TYPE(fdesc, value, prefix, int32, int64, uint32, uint64, float, double, bool, string, enum, message __VA_OPT__(,) __VA_ARGS__)

#define FORMAT_CPP_TYPE_TITLECASE(fdesc, value, prefix, ...) _FORMAT_CPP_TYPE(fdesc, value, prefix, Int32, Int64, UInt32, UInt64, Float, Double, Bool, String, Enum, Message __VA_OPT__(,) __VA_ARGS__)

extern std::string current_process_type;
inline std::string generate_address() {
    std::filesystem::path tmpdir = std::filesystem::temp_directory_path();
    std::filesystem::path sockpath = tmpdir / std::filesystem::path("looper_" + current_process_type + ".");
    const char *chars = "abcdefghijklmnopqrtsuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890._";
    for (size_t i = 0; i < 64; i++) {
        char chr = chars[rand() % strlen(chars)];
        sockpath += chr;
    }
    sockpath += ".sock";
    return "unix:" + std::string(sockpath);
}
template<class C>
class IPCClient {
    public:
    using Stub = std::unique_ptr<typename C::Stub>;
    std::shared_ptr<grpc::ChannelInterface> channel;
    IPCClient(std::string address) {
    	DEBUG.writefln("Connecting to '%s'...", address.c_str());
        channel = grpc::CreateChannel(address, grpc::InsecureChannelCredentials());
        channel->WaitForConnected(gpr_time_from_seconds(30, gpr_clock_type::GPR_CLOCK_MONOTONIC));
        DEBUG.writefln("Connection successful!");
    }

    Stub client_stub() {
        return C::NewStub(channel);
    }
};
template<class S>
class IPCServer {
    std::optional<std::shared_ptr<grpc::Server>> server;
    std::string address;
    using Service = S;
    public:
    using ServiceConstructor = std::function<grpc::Service*()>;
    private:
    void init_address(std::string address) {
        this->address = address;
    }
    void init_address() {
        init_address(generate_address());
    }
    void init(ServiceConstructor custom_service_constructor) {
        this->address = address;
        grpc::ServerBuilder builder;
        grpc::Service *service = nullptr;
        service = custom_service_constructor();
        builder.AddListeningPort(address, grpc::InsecureServerCredentials());
        builder.RegisterService(service);
        server = std::shared_ptr<grpc::Server>(builder.BuildAndStart().release());
        DEBUG.writefln("Server listening on '%s'...", address.c_str());
    }
    template<class SI>
    void init() {
        return init([]() {
            return new SI();
        });
    }
    public:
    inline std::shared_ptr<grpc::Server> get_server() {
        return server.value();
    }
    std::string get_address() {
        return address;
    }
    template<class SI>
    IPCServer(std::string address) {
        init_address(address);
        init<SI>();
    }
    template<class SI>
    IPCServer() {
        init_address();
        init<SI>();
    }
    IPCServer(ServiceConstructor custom_service_constructor) {
        init_address();
        init(custom_service_constructor);
    }
    IPCServer(std::string address, ServiceConstructor custom_service_constructor) {
        init_address(address);
        init(custom_service_constructor);
    }
};
template<class S, class C>
class IPCChannel {
    using Client = IPCClient<C>;
    using Server = IPCServer<S>;
    using ClientPtr = std::shared_ptr<Client>;
    using ServerPtr = std::shared_ptr<Server>;
    using ServiceConstructor = typename Server::ServiceConstructor;
    std::optional<ClientPtr> client = {};
    ServerPtr server;
    void init_client(ClientPtr client) {
        this->client = client;
    }
    void init_client(Client *client) {
        init_client(ClientPtr(client));
    }
    void init_server(ServerPtr server) {
        this->server = server;
    }
    void init_server(Server *server) {
        init_server(ServerPtr(server));
    }
    void init_client(std::string client_address) {
        init_client(new Client(client_address));
    }
    void init_server(std::string server_address, typename Server::ServiceConstructor constructor) {
        init_server(new Server(server_address, constructor));
    }
    void init_server(typename Server::ServiceConstructor constructor) {
        init_server(new Server(constructor));
    }
    public:
    using Stub = typename Client::Stub;
    bool has_client() const {
        return client.has_value();
    }
    Stub get_stub() {
        if (!has_client()) {
            ERROR.writeln("Attempt to get client stub for nonexistant client!");
            throw std::exception();
        }
        return get_client()->client_stub();
    }
    ServerPtr get_server() {
        return server;
    }
    const ServerPtr get_server() const {
        return server;
    }
    ClientPtr get_client() {
        return client.value();
    }
    const ClientPtr get_client() const {
        return client.value();
    }
    void set_client(ClientPtr client) {
        if (this->client.has_value()) return;
        init_client(client);
    }
    void construct_client(std::string client_address) {
        if (this->client.has_value()) {
            ERROR.writefln("Invalid attempt to construct client for address %s", client_address.c_str());
            return;
        } else {
            DEBUG.writefln("Constructing client for address %s...", client_address.c_str());
        }
        init_client(client_address);
    }
    /// @brief Constructs an IP channel with a newly-created server with a generated address.
    IPCChannel(ServiceConstructor custom_service_constructor) {
        init_server(custom_service_constructor);
    }
    /// @brief Constructs an IPC channel with a specific address for the server, creating a new server in the process
    /// @param address The address to use
    IPCChannel(std::string address, ServiceConstructor custom_service_constructor = {}) {
        init_server(address, custom_service_constructor);
    }
    /// @brief Constructs an IPC channel with only an already-existing server.
    /// @param server_init The existing server to use
    IPCChannel(ServerPtr server_init) {
        init_server(server_init);
    }
};