Initial commit: extracted from memex

src/protocol.lisp

@@ -0,0 +1,26 @@
+(in-package :org-agent)
+
+(defun frame-message (msg-string)
+  "Prefix MSG-STRING with a 6-character hex length (lowercase)."
+  (let ((len (length msg-string)))
+    (format nil "~(~6,'0x~)~a" len msg-string)))
+
+(defun parse-message (framed-string)
+  "Extract and parse the S-expression from a framed string."
+  (when (< (length framed-string) 6)
+    (error "Framed string too short"))
+  (let* ((len-str (subseq framed-string 0 6))
+         (actual-msg (subseq framed-string 6))
+         (expected-len (ignore-errors (parse-integer len-str :radix 16))))
+    (unless expected-len
+      (error "Invalid hex length prefix: ~a" len-str))
+    (unless (= expected-len (length actual-msg))
+      (error "Message length mismatch. Expected ~a, got ~a" expected-len (length actual-msg)))
+    (read-from-string actual-msg)))
+
+(defun make-hello-message (version)
+  "Construct the standard HELLO handshake message."
+  (list :type :EVENT 
+        :payload (list :action :handshake 
+                       :version version 
+                       :capabilities '(:auth :swank :org-ast))))