slige/runtime/rpc_server.cpp

#include "rpc_server.hpp"

extern "C" {
#include <arpa/inet.h>
#include <asm-generic/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <string>
#include <sys/socket.h>
#include <unistd.h>
}

using namespace sliger::rpc;

static auto create_address(uint16_t port) -> sockaddr_in
{
    return {
        .sin_family = AF_INET,
        .sin_port = ::htons(port),
        .sin_addr = { .s_addr = ::inet_addr("127.0.0.1") },
        .sin_zero = { 0 },
    };
}

auto Socket::init() -> Res<void>
{
    this->socket_fd = ::socket(AF_INET, SOCK_STREAM, 0);
    if (socket_fd < 0) {
        return Err { .msg
            = std::format("could not get socket ({})", socket_fd) };
    };
    this->initialized = true;

    int trueValue = 1;
    ::setsockopt(
        this->socket_fd, SOL_SOCKET, SO_REUSEADDR, &trueValue, sizeof(int));

    int err;

    auto address = create_address(13370);
    err = ::bind(socket_fd, (struct sockaddr*)&address, sizeof(address));
    if (err < 0) {
        return Err { .msg = std::format("could not bind ({})", err) };
    };

    err = ::listen(socket_fd, 0);
    if (err < 0) {
        return Err { .msg = std::format("could not listen ({})", err) };
    }
    return {};
}

auto Socket::accept() -> Res<std::unique_ptr<Client>>
{
    auto client_address = create_address(13370);
    socklen_t address_size = sizeof(client_address);
    int client
        = ::accept(socket_fd, (struct sockaddr*)&client_address, &address_size);
    if (client < 0) {
        return Err { .msg = std::format("could not accept ({})", client) };
    }
    return std::make_unique<Client>(client);
}
auto Client::read(int8_t* buffer, size_t buffer_size) -> ssize_t
{
    return ::read(this->client_sock, buffer, buffer_size);
}
auto Client::write(uint8_t* buffer, size_t buffer_size) -> ssize_t
{
    return ::write(this->client_sock, buffer, buffer_size);
}

auto BufferedWriter::write(std::string message) -> Res<void>
{
    for (auto ch : message) {
        if (auto res = this->write((uint8_t)ch); !res.is_ok()) {
            return res.err();
        }
    }
    return {};
}

auto BufferedWriter::write(uint8_t byte) -> Res<void>
{
    if (this->occupied >= length) {
        if (auto res = this->flush(); !res.is_ok()) {
            return res.err();
        }
    }
    this->buffer[this->occupied] = byte;
    this->occupied += 1;

    return {};
}

auto BufferedWriter::flush() -> Res<size_t>
{
    auto result = this->client->write(this->buffer, this->occupied);
    if (result < 0) {
        return Err("unable to write");
    }
    this->occupied = 0;
    return (size_t)result;
}