1 files changed, 52 insertions, 0 deletions
diff --git a/src/proto/backend_key_data.zig b/src/proto/backend_key_data.zig
new file mode 100644
index 0000000..7c32178
--- /dev/null
+++ b/src/proto/backend_key_data.zig
@@ -0,0 +1,52 @@
+const std = @import("std");
+const log = std.log.scoped(.pgz);
+const ByteArrayList = std.ArrayList(u8);
+const ProtocolError = @import("../main.zig").ProtocolError;
+const ClientError = @import("../main.zig").ClientError;
+
+const BackendKeyData = @This();
+pub const Tag: u8 = 'K';
+
+process_id: u32,
+secret_key: u32,
+
+pub fn read(_: std.mem.Allocator, b: []const u8) !BackendKeyData {
+    if (b.len != 8) return ProtocolError.InvalidMessageLength;
+    return .{
+        .process_id = std.mem.readIntBig(u32, b[0..4]),
+        .secret_key = std.mem.readIntBig(u32, b[4..8]),
+    };
+}
+pub fn write(self: BackendKeyData, _: std.mem.Allocator, stream_writer: anytype) !void {
+    try stream_writer.writeByte(Tag);
+    try stream_writer.writeIntBig(u32, 12); // length
+    try stream_writer.writeIntBig(u32, self.process_id);
+    try stream_writer.writeIntBig(u32, self.secret_key);
+}
+pub fn deinit(_: *BackendKeyData, _: std.mem.Allocator) void {}
+
+test "round trip" {
+    const allocator = std.testing.allocator;
+    var sm = BackendKeyData{
+        .process_id = 123,
+        .secret_key = 345,
+    };
+    defer sm.deinit(allocator);
+
+    var bal = ByteArrayList.init(allocator);
+    defer bal.deinit();
+    try sm.write(allocator, bal.writer());
+
+    var fbs = std.io.fixedBufferStream(bal.items);
+    var reader = fbs.reader();
+    const tag = try reader.readByte();
+    try std.testing.expectEqual(Tag, tag);
+    const len = try reader.readIntBig(u32);
+    const buf = try allocator.alloc(u8, len - 4);
+    defer allocator.free(buf);
+    try reader.readNoEof(buf);
+    var sm2 = try BackendKeyData.read(allocator, buf);
+    defer sm2.deinit(allocator);
+    try std.testing.expectEqual(@as(u32, 123), sm2.process_id);
+    try std.testing.expectEqual(@as(u32, 345), sm2.secret_key);
+}