fix: handle ack+packet strings

src/Packet.zig

@@ -19,8 +19,6 @@ pub fn from(allocator: Allocator, str: []const u8) !Self {
     const chksum_str = tokens.next() orelse return error.MissingCheckSum;
     const chksum = std.fmt.parseInt(u8, chksum_str, 16) catch return error.InvalidChecksum;
 
-    // log.info("Contents: {s}", .{contents});
-
     if (!Self.verify(contents, chksum)) return error.ChecksumMismatch;
 
     return .{ .contents = try allocator.dupe(u8, contents) };
@@ -99,10 +97,8 @@ pub fn parse(self: *Self, allocator: Allocator, emu: Emulator) !String {
         'M' => @panic("TODO: Memory Write"),
         'c' => @panic("TODO: Continue"),
         's' => {
-            var tokens = std.mem.tokenize(u8, self.contents[1..], " ");
+            // var tokens = std.mem.tokenize(u8, self.contents[1..], " ");
-            const addr = if (tokens.next()) |s| try std.fmt.parseInt(u32, s, 16) else null;
+            // const addr = if (tokens.next()) |s| try std.fmt.parseInt(u32, s, 16) else null;
-
-            log.debug("s addr: {?X:0>8}", .{addr});
 
             emu.step();
 
@@ -111,18 +107,8 @@ pub fn parse(self: *Self, allocator: Allocator, emu: Emulator) !String {
         },
 
         // Optional
-        // 'S' => {
-        //     var tokens = std.mem.tokenize(u8, self.contents[1..], " ");
-        //     const signal = if (tokens.next()) |s| try std.fmt.parseInt(u8, s, 16) else null;
-        //     log.debug("S signal: {?}", .{signal});
-
-        //     emu.step();
-
-        //     const ret = try std.fmt.allocPrint(allocator, "S{x:0>2}", .{@enumToInt(Signal.Trap)});
-        //     return .{ .alloc = ret };
-        // },
         'D' => {
-            log.info("Disconneccting...", .{});
+            log.info("Disconnecting...", .{});
             return .{ .static = "OK" };
         },
         'H' => return .{ .static = "" },
@@ -153,13 +139,11 @@ pub fn parse(self: *Self, allocator: Allocator, emu: Emulator) !String {
                 _ = tokens.next(); // Xfer
                 _ = tokens.next(); // features
                 _ = tokens.next(); // read
-                const annex = tokens.next() orelse return .{ .static = "E00" };
+                const annex = tokens.next() orelse return .{ .static = "E9999" };
-                const offset_str = tokens.next() orelse return .{ .static = "E00" };
+                const offset_str = tokens.next() orelse return .{ .static = "E99999" };
-                const length_str = tokens.next() orelse return .{ .static = "E00" };
+                const length_str = tokens.next() orelse return .{ .static = "E9999" };
 
                 if (std.mem.eql(u8, annex, "target.xml")) {
-                    log.info("Providing ARMv4T target description", .{});
-
                     const offset = try std.fmt.parseInt(usize, offset_str, 16);
                     const length = try std.fmt.parseInt(usize, length_str, 16);
 
@@ -175,7 +159,7 @@ pub fn parse(self: *Self, allocator: Allocator, emu: Emulator) !String {
                     return .{ .alloc = ret };
                 } else {
                     log.err("Unexpected Annex: {s}", .{annex});
-                    return .{ .static = "E00" };
+                    return .{ .static = "E9999" };
                 }
 
                 return .{ .static = "" };
@@ -189,8 +173,6 @@ pub fn parse(self: *Self, allocator: Allocator, emu: Emulator) !String {
                 const offset_str = tokens.next() orelse return .{ .static = "E9999" };
                 const length_str = tokens.next() orelse return .{ .static = "E9999" };
 
-                log.info("Providing GBA memory map", .{});
-
                 const offset = try std.fmt.parseInt(usize, offset_str, 16);
                 const length = try std.fmt.parseInt(usize, length_str, 16);
 

src/Server.zig

@@ -107,34 +107,44 @@ pub fn run(self: *Self, allocator: Allocator) !void {
 }
 
 fn parse(self: *Self, allocator: Allocator, input: []const u8) !Action {
+    // log.debug("-> {s}", .{input});
+
     return switch (input[0]) {
-        '+' => .nothing,
+        '+' => blk: {
-        '-' => .retry,
+            if (input.len == 1) break :blk .nothing;
-        '$' => blk: {
-            // Packet
-            var packet = Packet.from(allocator, input) catch return .nack;
-            defer packet.deinit(allocator);
 
-            var string = packet.parse(allocator, self.emu) catch return .nack;
+            break :blk switch (input[1]) {
-            defer string.deinit(allocator);
+                '$' => self.handlePacket(allocator, input[1..]),
-
+                else => std.debug.panic("Unknown: {s}", .{input}),
-            const reply = string.inner();
+            };
-
-            // deallocated by the caller
-            const response = try std.fmt.allocPrint(allocator, "${s}#{x:0>2}", .{ reply, Packet.checksum(reply) });
-
-            break :blk .{ .send = response };
         },
+        '-' => .retry,
+        '$' => try self.handlePacket(allocator, input),
         '\x03' => .nothing,
         else => std.debug.panic("Unknown: {s}", .{input}),
     };
 }
 
+fn handlePacket(self: *Self, allocator: Allocator, input: []const u8) !Action {
+    var packet = Packet.from(allocator, input) catch return .nack;
+    defer packet.deinit(allocator);
+
+    var string = packet.parse(allocator, self.emu) catch return .nack;
+    defer string.deinit(allocator);
+
+    const reply = string.inner();
+
+    // deallocated by the caller
+    const response = try std.fmt.allocPrint(allocator, "+${s}#{x:0>2}", .{ reply, Packet.checksum(reply) });
+
+    return .{ .send = response };
+}
+
 fn send(self: *Self, allocator: Allocator, action: Action) !void {
     switch (action) {
         .send => |pkt| {
-            _ = try self.client.send("+"); // ACK
             _ = try self.client.send(pkt);
+            // log.debug("<- {s}", .{pkt});
 
             self.reset(allocator);
             self.pkt_cache = pkt;
@@ -142,14 +152,21 @@ fn send(self: *Self, allocator: Allocator, action: Action) !void {
         .retry => {
             log.warn("received nack, resending: \"{?s}\"", .{self.pkt_cache});
 
-            if (self.pkt_cache) |pkt| _ = try self.client.send(pkt); // FIXME: is an ack to a nack necessary?
+            if (self.pkt_cache) |pkt| {
+                _ = try self.client.send(pkt);
+                // log.debug("<- {s}", .{pkt});
+            }
         },
         .ack => {
             _ = try self.client.send("+");
+            // log.debug("<- +", .{});
+
             self.reset(allocator);
         },
         .nack => {
             _ = try self.client.send("-");
+            // log.debug("<- -", .{});
+
             self.reset(allocator);
         },
         .nothing => self.reset(allocator),