Use Client as var type instead of singleton

src/Client.zig

@@ -1,29 +1,36 @@
 const base64Enc = std.base64.Base64Encoder.init(std.base64.standard_alphabet_chars, '=');
 const base64Dec = std.base64.Base64Decoder.init(std.base64.standard_alphabet_chars, '=');
 
-var rand: ?Random = null;
-var socket: ?gcat.nic.RawSocket = null;
+rand: Random,
+socket: gcat.nic.RawSocket,
+
+const Self = @This();
 
 const max_message_size = 2048;
 
-pub fn init() !void {
+pub fn init(interface_name: [:0]const u8) !Self {
     var prng = Random.DefaultPrng.init(blk: {
         var seed: u64 = undefined;
         try posix.getrandom(mem.asBytes(&seed));
         break :blk seed;
     });
-    rand = prng.random();
+    const rand = prng.random();
 
-    socket = try .init("enp7s0");
+    const socket: gcat.nic.RawSocket = try .init(interface_name);
+
+    return .{
+        .rand = rand,
+        .socket = socket,
+    };
 }
 
-pub fn deinit() void {
-    socket.?.deinit();
+pub fn deinit(self: *Self) void {
+    self.socket.deinit();
 }
 
 /// Used for relay messages and connection handshake.
 /// Assumes Client .init has been called.
-fn broadcastInitialInterestMessage(msg_bytes: []align(@alignOf(SaprusMessage)) u8) !void {
+fn broadcastInitialInterestMessage(self: *Self, msg_bytes: []align(@alignOf(SaprusMessage)) u8) !void {
     var packet_bytes: [max_message_size]u8 = comptime blk: {
         var b: [max_message_size]u8 = @splat(0);
 
@@ -63,7 +70,7 @@ fn broadcastInitialInterestMessage(msg_bytes: []align(@alignOf(SaprusMessage)) u
     const saprus_start_byte = 42;
     @memcpy(packet_bytes[saprus_start_byte .. saprus_start_byte + msg_bytes.len], msg_bytes);
 
-    try socket.?.linkLayer().send(packet_bytes[0 .. saprus_start_byte + msg_bytes.len]);
+    try self.socket.linkLayer().send(packet_bytes[0 .. saprus_start_byte + msg_bytes.len]);
 }
 
 // fn broadcastSaprusMessage(msg_bytes: []align(@alignOf(SaprusMessage)) u8) !void {}
@@ -100,7 +107,7 @@ fn broadcastSaprusMessage(msg_bytes: []align(@alignOf(SaprusMessage)) u8, udp_po
     _ = try sock.sendTo(dest_addr, msg_bytes);
 }
 
-pub fn sendRelay(payload: []const u8, dest: [4]u8) !void {
+pub fn sendRelay(self: *Self, payload: []const u8, dest: [4]u8) !void {
     var buf: [max_message_size]u8 align(@alignOf(SaprusMessage)) = undefined;
     const msg_bytes = buf[0..try SaprusMessage.calcSize(
         .relay,
@@ -112,24 +119,20 @@ pub fn sendRelay(payload: []const u8, dest: [4]u8) !void {
     relay.dest = dest;
     _ = base64Enc.encode(relay.getPayload(), payload);
 
-    try broadcastInitialInterestMessage(msg_bytes);
+    try self.broadcastInitialInterestMessage(msg_bytes);
 }
 
-fn randomPort() u16 {
-    var p: u16 = 0;
-    if (rand) |r| {
-        p = r.intRangeAtMost(u16, 1024, 65000);
-    } else unreachable;
-
-    return p;
+fn randomPort(self: Self) u16 {
+    return self.rand.intRangeAtMost(u16, 1024, 65000);
 }
 
 pub fn sendInitialConnection(
+    self: Self,
     payload: []const u8,
     output_bytes: []align(@alignOf(SaprusMessage)) u8,
     initial_port: u16,
 ) !*SaprusMessage {
-    const dest_port = randomPort();
+    const dest_port = self.randomPort();
     const msg_bytes = output_bytes[0..try SaprusMessage.calcSize(
         .connection,
         base64Enc.calcSize(payload.len),
@@ -146,8 +149,8 @@ pub fn sendInitialConnection(
     return msg;
 }
 
-pub fn connect(payload: []const u8) !?SaprusConnection {
-    const initial_port = randomPort();
+pub fn connect(self: Self, payload: []const u8) !?SaprusConnection {
+    const initial_port = self.randomPort();
 
     var initial_conn_res: ?*SaprusMessage = null;
 
@@ -165,7 +168,7 @@ pub fn connect(payload: []const u8) !?SaprusConnection {
     try sock.bind(bind_addr);
 
     var sent_msg_bytes: [max_message_size]u8 align(@alignOf(SaprusMessage)) = undefined;
-    const msg = try sendInitialConnection(payload, &sent_msg_bytes, initial_port);
+    const msg = try self.sendInitialConnection(payload, &sent_msg_bytes, initial_port);
 
     var response_buf: [max_message_size]u8 align(@alignOf(SaprusMessage)) = undefined;
     _ = try sock.receive(&response_buf); // Ignore message that I sent.
@@ -174,7 +177,7 @@ pub fn connect(payload: []const u8) !?SaprusConnection {
     initial_conn_res = try .networkBytesAsValue(response_buf[0..len]);
 
     // Complete handshake after awaiting response
-    try broadcastSaprusMessage(msg.asBytes(), randomPort());
+    try broadcastSaprusMessage(msg.asBytes(), self.randomPort());
 
     if (false) {
         return initial_conn_res.?;

src/main.zig

@@ -42,23 +42,23 @@ pub fn main() !void {
     };
     defer res.deinit();
 
-    try SaprusClient.init();
-    defer SaprusClient.deinit();
-
     if (res.args.help != 0) {
         return clap.help(std.io.getStdErr().writer(), clap.Help, &params, .{});
     }
 
+    var client = try SaprusClient.init("enp7s0");
+    defer client.deinit();
+
     if (res.args.relay) |r| {
         const dest = parseDest(res.args.dest);
-        try SaprusClient.sendRelay(
+        try client.sendRelay(
             if (r.len > 0) r else "Hello darkness my old friend",
             dest,
         );
         // std.debug.print("Sent: {s}\n", .{r});
         return;
     } else if (res.args.connect) |c| {
-        _ = SaprusClient.connect(if (c.len > 0) c else "Hello darkness my old friend") catch |err| switch (err) {
+        _ = client.connect(if (c.len > 0) c else "Hello darkness my old friend") catch |err| switch (err) {
             error.WouldBlock => null,
             else => return err,
         };