Proof of concept

packages/myid/src/http.zig

@@ -0,0 +1,66 @@
+const std = @import("std");
+const main = @import("main.zig");
+
+threadlocal var read_buffer: [2 * 1024 * 1024]u8 = undefined;
+threadlocal var write_buffer: [2 * 1024 * 1024]u8 = undefined;
+
+const http_400 = "HTTP/1.1 400 Bad Request\r\n\r\n";
+const http_404 = "HTTP/1.1 404 Not Found\r\n\r\n";
+const http_413 = "HTTP/1.1 413 Content Too Large\r\n\r\n";
+const http_431 = "HTTP/1.1 431 Request Header Fields Too Large\r\n\r\n";
+const http_500 = "HTTP/1.1 500 Internal Server Error\r\n\r\n";
+
+const log = std.log.scoped(.http);
+
+fn http_200(content_type: []const u8, response_body: []const u8) ![]const u8 {
+    var fbs = std.io.fixedBufferStream(&write_buffer);
+    const writer = fbs.writer();
+
+    try writer.print("HTTP/1.1 200 OK\r\n", .{});
+    try writer.print("Content-Type: {s}\r\n", .{content_type});
+    try writer.print("Content-Length: {d}\r\n", .{response_body.len});
+    try writer.print("\r\n", .{});
+    try writer.print("{s}", .{response_body});
+
+    return fbs.getWritten();
+}
+
+pub fn process(conn: std.net.Server.Connection) !void {
+    defer conn.stream.close();
+
+    var arena = std.heap.ArenaAllocator.init(main.allocator);
+    defer arena.deinit();
+
+    const allocator = arena.allocator();
+    _ = allocator;
+
+    var running = true;
+    while (running) {
+        var header_end: ?usize = null;
+        var request_len: usize = 0;
+
+        const request_head = blk: while (conn.stream.read(read_buffer[request_len..])) |len| {
+            if (len == 0) {
+                running = false;
+                return;
+            }
+
+            header_end = std.mem.indexOfPos(u8, &read_buffer, request_len, "\r\n\r\n");
+            request_len += len;
+
+            if (header_end) |end| {
+                break :blk read_buffer[0..end];
+            }
+        } else |err| {
+            return err;
+        };
+
+        const response = try http_200("text/plain; charset=utf-8", "PONG\n");
+
+        try conn.stream.writeAll(response);
+
+        if (request_len > request_head.len + 4) {
+            @memmove(&read_buffer, read_buffer[request_head.len + 4 .. request_len]);
+        }
+    }
+}