Align the bytes instead of the struct

src/message.zig

@@ -36,9 +36,7 @@ pub const ZeroCopyMessage = packed struct {
         dest: @Vector(4, u8),
         payload: void,
 
-        const RSelf = *align(1) @This();
-
-        pub fn getPayload(self: RSelf) []u8 {
+        pub fn getPayload(self: *align(1) Relay) []u8 {
             const len: *u16 = @ptrFromInt(@intFromPtr(self) - @sizeOf(u16));
             return @as([*]u8, @ptrCast(&self.payload))[0 .. len.* - @sizeOf(Relay)];
         }
@@ -52,21 +50,19 @@ pub const ZeroCopyMessage = packed struct {
         options: ConnectionOptions = .{},
         payload: void,
 
-        const CSelf = *align(1) Connection;
-
-        pub fn getPayload(self: CSelf) []u8 {
+        pub fn getPayload(self: *align(1) Connection) []u8 {
             const len: *u16 = @ptrFromInt(@intFromPtr(self) - @sizeOf(u16));
             return @as([*]u8, @ptrCast(&self.payload))[0 .. len.* - @sizeOf(Connection)];
         }
 
-        fn nativeFromNetworkEndian(self: CSelf) Error!void {
+        fn nativeFromNetworkEndian(self: *align(1) Connection) Error!void {
             self.src_port = bigToNative(@TypeOf(self.src_port), self.src_port);
             self.dest_port = bigToNative(@TypeOf(self.dest_port), self.dest_port);
             self.seq_num = bigToNative(@TypeOf(self.seq_num), self.seq_num);
             self.msg_id = bigToNative(@TypeOf(self.msg_id), self.msg_id);
         }
 
-        fn networkFromNativeEndian(self: CSelf) Error!void {
+        fn networkFromNativeEndian(self: *align(1) Connection) Error!void {
             self.src_port = nativeToBig(@TypeOf(self.src_port), self.src_port);
             self.dest_port = nativeToBig(@TypeOf(self.dest_port), self.dest_port);
             self.seq_num = nativeToBig(@TypeOf(self.seq_num), self.seq_num);
@@ -80,14 +76,14 @@ pub const ZeroCopyMessage = packed struct {
     length: u16,
     bytes: void = {},
 
-    fn getRelay(self: ZCM) Relay.RSelf {
+    fn getRelay(self: *Self) *align(1) Relay {
         return std.mem.bytesAsValue(Relay, &self.bytes);
     }
-    fn getConnection(self: ZCM) Connection.CSelf {
+    fn getConnection(self: *Self) *align(1) Connection {
         return std.mem.bytesAsValue(Connection, &self.bytes);
     }
 
-    pub fn getSaprusTypePayload(self: ZCM) Error!(union(PacketType) {
+    pub fn getSaprusTypePayload(self: *Self) Error!(union(PacketType) {
         relay: *align(1) Relay,
         file_transfer: void,
         connection: *align(1) Connection,
@@ -100,7 +96,7 @@ pub const ZeroCopyMessage = packed struct {
         };
     }
 
-    pub fn nativeFromNetworkEndian(self: ZCM) Error!void {
+    pub fn nativeFromNetworkEndian(self: *Self) Error!void {
         self.type = @enumFromInt(bigToNative(
             @typeInfo(@TypeOf(self.type)).@"enum".tag_type,
             @intFromEnum(self.type),
@@ -114,7 +110,7 @@ pub const ZeroCopyMessage = packed struct {
         };
     }
 
-    pub fn networkFromNativeEndian(self: ZCM) Error!void {
+    pub fn networkFromNativeEndian(self: *Self) Error!void {
         try switch (try self.getSaprusTypePayload()) {
             .relay => {},
             .connection => |*con| con.*.networkFromNativeEndian(),
@@ -128,26 +124,24 @@ pub const ZeroCopyMessage = packed struct {
         self.length = nativeToBig(@TypeOf(self.length), self.length);
     }
 
-    pub fn fromBytesUnchecked(bytes: []u8) ZCM {
-        return @ptrCast(bytes.ptr);
+    pub fn fromBytesUnchecked(bytes: []align(@alignOf(Self)) u8) *Self {
+        return @ptrCast(@alignCast(bytes.ptr));
     }
 
-    pub fn fromBytes(bytes: []u8) !ZCM {
-        const res: ZCM = @ptrCast(bytes.ptr);
+    pub fn fromBytes(bytes: []align(@alignOf(Self)) u8) !*Self {
+        const res: *Self = @ptrCast(@alignCast(bytes.ptr));
         return if (bytes.len == res.length + @sizeOf(Self)) res else Error.InvalidMessage;
     }
 };
 
-const ZCM = *align(1) ZeroCopyMessage;
-
 test "testing variable length zero copy struct" {
     const gpa = std.testing.allocator;
     const payload_len = 48;
-    const bytes = try gpa.alloc(u8, @sizeOf(ZeroCopyMessage) + payload_len);
+    const bytes = try gpa.alignedAlloc(u8, @alignOf(ZeroCopyMessage), @sizeOf(ZeroCopyMessage) + payload_len);
     defer gpa.free(bytes);
 
     // Create a view of the byte slice as a ZeroCopyMessage
-    const zcm: ZCM = .fromBytesUnchecked(bytes);
+    const zcm: *ZeroCopyMessage = .fromBytesUnchecked(bytes);
 
     {
         // Set the message values