http.Server - std

A basic implementation of http.Server has been introduced since Zig 0.12.0.

For each connection we spawn a new thread to handle it, in accept it will:

First it use defer to ensure the connection is closed when returned.
Then init a HTTP server to begin parse request
For each request, we first check if it could upgrade to WebSocket.
- If it succeeds, call serveWebSocket else call serverHTTP

const std = @import("std"); const log = std.log; const Request = std.http.Server.Request; const Connection = std.net.Server.Connection; const MAX_BUF = 1024; pub fn main() !void { const addr = try std.net.Address.parseIp("127.0.0.1", 8080); var server = try std.net.Address.listen(addr, .{ .reuse_address = true }); defer server.deinit(); log.info("Start HTTP server at {f}", .{addr}); while (true) { const conn = server.accept() catch |err| { log.err("failed to accept connection: {s}", .{@errorName(err)}); continue; }; _ = std.Thread.spawn(.{}, accept, .{conn}) catch |err| { log.err("unable to spawn connection thread: {s}", .{@errorName(err)}); conn.stream.close(); continue; }; } } fn accept(conn: Connection) !void { defer conn.stream.close(); log.info("Got new client({f})!", .{conn.address}); var recv_buffer: [1024]u8 = undefined; var send_buffer: [100]u8 = undefined; var connection_br = conn.stream.reader(&recv_buffer); var connection_bw = conn.stream.writer(&send_buffer); var server = std.http.Server.init(connection_br.interface(), &connection_bw.interface); while (server.reader.state == .ready) { var request = server.receiveHead() catch |err| switch (err) { error.HttpConnectionClosing => return, else => return err, }; switch (request.upgradeRequested()) { .other => |other_protocol| { log.err("Not supported protocol, {s}", .{other_protocol}); return; }, .websocket => |key| { var ws = try request.respondWebSocket(.{ .key = key orelse "" }); try serveWebSocket(&ws); }, .none => { try serveHTTP(&request); }, } } } fn serveHTTP(request: *Request) !void { try request.respond( "Hello World from Zig HTTP server", .{ .extra_headers = &.{ .{ .name = "custom-header", .value = "custom value" }, }, }, ); } fn serveWebSocket(ws: *std.http.Server.WebSocket) !void { try ws.writeMessage("Hello from Zig WebSocket server", .text); while (true) { const msg = try ws.readSmallMessage(); if (msg.opcode == .connection_close) { log.info("Client closed the WebSocket", .{}); return; } try ws.writeMessage(msg.data, msg.opcode); } }

Test

For HTTP, we could use curl:

curl -v localhost:8080

It will output:

< HTTP/1.1 200 OK < content-length: 32 < custom header: custom value < Hello World from Zig HTTP server

For WebSocket, we could use console in your browser’s Developer Tools:

var webSocket = new WebSocket('ws://localhost:8080'); webSocket.onmessage = function(data) { console.log(data); }

Then we could send message like this:

webSocket.send('abc')

See Writing WebSocket client applications - Web APIs | MDN for details.

Note

The std implementation exhibits extremely poor performance. If you’re planning beyond basic experimentation, consider utilizing alternative libraries such as: