protohackers

commit 3579fe196cf9399a86a275fa264bd0c0f7d5d44b
parent 894daa68c1e86b41d03d041bd550eef059fcfb52
Author: Henry Wilson <henry@henryandlizzy.uk>
Date:   Wed, 30 Aug 2023 17:54:29 +0000

General improvements to protohack-0

Diffstat:
M
fd.hpp
 | 
19
+++++++++++++++++--
M
inet.hpp
 | 
2
+-
M
protohack-0.cpp
 | 
65
++++++++++++++++++++++++++++++++++++-----------------------------

3 files changed, 54 insertions(+), 32 deletions(-)
diff --git a/fd.hpp b/fd.hpp
@@ -1,7 +1,9 @@
 #pragma once
 #include <unistd.h>
+#include <err.h>
 
 #include <string>
+#include <span>
 
 struct descriptor
 {
@@ -59,9 +61,11 @@ private:
 	int fd;
 };
 
-int write(descriptor& d, std::string_view s)
+ssize_t write(int d, std::string_view s)
 {
-	return ::write(d, s.data(), s.size());
+	if (ssize_t n = ::write(d, s.data(), s.size()); n != -1)
+		return n;
+	::err(1, "write");
 }
 
 std::string read(descriptor& d)
@@ -73,3 +77,14 @@ std::string read(descriptor& d)
 	else
 		return {};
 }
+
+std::string_view read(int d, std::span<char> buf)
+{
+	ssize_t n = ::read(d, buf.data(), buf.size());
+	if ((n < 0) or ((size_t)n > buf.size()))
+		err(1, "read");
+	else if (n)
+		return {buf.data(), (size_t)n};
+	else
+		return {};
+}
diff --git a/inet.hpp b/inet.hpp
@@ -14,7 +14,7 @@ namespace inet {
 
 descriptor listen(int type)
 {
-	struct sockaddr_in addr {sizeof addr, AF_INET, htons(1337), INADDR_ANY};
+	struct sockaddr_in addr {sizeof addr, AF_INET, htons(1337), {INADDR_ANY}, {}};
 	int reuseaddr = 1;
 
 	descriptor incoming{::socket(AF_INET, type, 0)};
diff --git a/protohack-0.cpp b/protohack-0.cpp
@@ -2,61 +2,68 @@
 
 #include <poll.h>
 
+#include <algorithm>
 #include <iostream>
-#include <sstream>
-#include <span>
 #include <map>
-#include <vector>
 
-struct client
+int poll(std::span<struct pollfd> pfds, int timeout = INFTIM)
 {
-	descriptor socket;
-	std::string buffer;
-};
+	if (int n = ::poll(pfds.data(), pfds.size(), timeout); n != -1)
+		return n;
+	err(1, "poll");
+}
 
 int main()
 {
-	std::map<int, client> clients;
-	std::vector<pollfd> awaitables;
-	auto incoming = inet::listen(SOCK_STREAM);
+	std::map<int, descriptor> clients;
+	auto incoming_socket = inet::listen(SOCK_STREAM);
+	std::cout << "Protohack 0: Smoke Test\n";
 
 	for (;;)
 	{
-		awaitables.clear();
-		awaitables.push_back(pollfd{incoming, POLLIN, 0});
+		size_t const pollen = clients.size() + 1;
+		pollfd events_buf[pollen];
+		std::span events{events_buf, pollen};
+
+		auto& socket_event = events.front();
+		auto client_events = events.subspan(1);
+
+		socket_event = pollfd{incoming_socket, POLLIN, 0};
 
-		for (auto const& c : clients)
-			awaitables.push_back(pollfd{c.second.socket, POLLIN, 0});
+		std::transform(clients.cbegin(), clients.cend(), client_events.begin(), [](auto& c) {
+			return pollfd{c.second, POLLIN, 0};
+		});
 
-		if (::poll(awaitables.data(), awaitables.size(), INFTIM) == -1)
-			err(1, "poll");
+		int ready = poll(events);
 
-		if (awaitables.front().revents & POLLIN) // incoming
+		if (socket_event.revents & POLLIN)
 		{
-			auto conn = inet::accept(incoming);
-			clients[conn] = {std::move(conn), {}};
+			auto conn = inet::accept(incoming_socket);
+			clients[conn] = std::move(conn);
+			if (not --ready)
+				continue;
 		}
 
-		for (auto& ev : std::span{awaitables}.subspan(1))
+		for (auto& ev : client_events)
 		{
 			if (~ev.revents & POLLIN)
 				continue;
 
-			char buf[0x1000];
-			int n = ::read(ev.fd, buf, sizeof buf);
-			if (not n)
+			char data_buf[0x1000];
+			auto data = read(ev.fd, std::span{data_buf});
+
+			if (data.empty())
 			{
 				std::cout << "* " << ev.fd << " disconnected\n";
 				clients.erase(ev.fd);
 				continue;
 			}
-			if (n < 0 or n > sizeof buf)
-				err(1, "read");
 
-			std::cout << "* " << ev.fd << ": " << n << " bytes\n";
-			::write(1, buf, n);
-			//if (n != ::write(ev.fd, buf, n))
-			//	err(1, "write");
+			std::cout << "* " << ev.fd << ": " << data.size() << " bytes\n";
+			write(ev.fd, data);
+
+			if (not --ready)
+				break;
 		}
 	}
 }