Moved out EPMD client code into new file epmd-client.lisp to prepare …

…for refactoring.

cleric.asd

@@ -33,7 +33,10 @@
                     :depends-on ("packages"
                                  "atom-cache"))
              (:file "epmd"
+                    :depends-on ("packages"))
+             (:file "epmd-client"
                     :depends-on ("packages"
+                                 "epmd"
                                  "listen"
                                  "local-node"
                                  "remote-node"))

src/epmd-client.lisp

@@ -0,0 +1,117 @@
+;;;; Functions for querying EPMD (Erlang Port Mapped Daemon)
+
+(in-package :cleric-epmd)
+
+;;; EPMD port
+(defconstant +epmd-port+ 4369
+  "The default TCP port the EPMD listens on.")
+
+(defvar *epmd-socket* nil
+  "The EPMD socket. NIL if not registered in EPMD.")
+
+
+
+(defun connect-to-epmd (&optional (host "localhost"))
+  (let ((socket (handler-case (usocket:socket-connect host
+                                                      +epmd-port+
+                                                      :element-type 'octet)
+                  (usocket:connection-refused-error ()
+                    (error 'unreachable-error))
+                  (usocket:unknown-error ()
+                    (error 'host-unknown-error)))))
+    (setf (usocket:socket-stream socket)
+          (make-flexi-stream (usocket:socket-stream socket)))
+    socket))
+
+
+;;;
+;;; WITH-EPMD-CONNECTION-STREAM macro
+;;;
+
+(defmacro with-epmd-connection-stream
+    ((stream-var &optional (host "localhost")) &body body)
+  "Create a local scope where STREAM-VAR is a socket stream connected to the EPMD."
+  (let ((socket-var (gensym)))
+    `(let* ((,socket-var (connect-to-epmd ,host))
+            (,stream-var (usocket:socket-stream ,socket-var)))
+       (unwind-protect (progn ,@body)
+         (usocket:socket-close ,socket-var))) ))
+
+
+;;;
+;;; EPMD API
+;;;
+
+(defun publish ()
+  (if *epmd-socket*
+      (error 'already-registered)
+      (restart-case
+          (if (not (listening-p))
+              (error 'not-listening-on-socket)
+              (let* ((socket (connect-to-epmd))
+                     (epmd (usocket:socket-stream socket)))
+                (write-alive2-request
+                 epmd (node-name (this-node)) (listening-port))
+                (finish-output epmd)
+                (let ((creation (read-alive2-response epmd)))
+                  (declare (ignore creation))
+                  (setf *epmd-socket* socket)
+                  t)))
+        (start-listening-on-socket ()
+          :report "Start listening on a socket."
+          :test (lambda (c)
+                  (declare (ignore c))
+                  (not (listening-p)))
+          (start-listening)
+          (publish)))))
+
+(defun published-p ()
+  (not (null *epmd-socket*)))
+
+(defun unpublish ()
+  (when *epmd-socket*
+    (usocket:socket-close *epmd-socket*)
+    (setf *epmd-socket* nil)
+    t))
+
+(defun lookup-node (node-name &optional (host "localhost"))
+  "Query the EPMD about a node. Returns a REMOTE-NODE object that represents the node."
+  (with-epmd-connection-stream (epmd host)
+    (write-port-please2-request epmd node-name)
+    (finish-output epmd)
+    (read-port-please2-response epmd host)))
+
+(defun print-all-registered-nodes (&optional (host "localhost") (stream t))
+  "Query the EPMD about all registered nodes and print the information."
+  (with-epmd-connection-stream (epmd host)
+    (write-names-request epmd)
+    (finish-output epmd)
+    (multiple-value-bind (epmd-port node-info)
+        (read-names-response epmd)
+      (declare (ignore epmd-port))
+      (format stream "~{~a~%~}" node-info)
+      t)))
+
+
+;;;
+;;; Conditions
+;;;
+
+(define-condition already-registered (error)
+  ()
+  (:documentation "This error is signaled when trying to register on the EPMD when already registered."))
+
+(define-condition host-unknown-error (error)
+  ;; USOCKET:UNKNOWN-ERROR
+  ()
+  (:documentation "This error is signaled if the hostname for EPMD is unresolvable."))
+
+(define-condition unreachable-error (error)
+  ;; USOCKET:CONNECTION-REFUSED-ERROR
+  ()
+  (:documentation "This error is signaled when the EPMD is unreachable."))
+
+(define-condition response-error (error)
+  ;; Useful?
+  ()
+  (:documentation "This error is signaled when the EPMD sends an error response."))

src/epmd.lisp

@@ -1,11 +1,7 @@
-;;;; Functions for querying EPMD (Erlang Port Mapped Daemon)
+;;;; The EPMD protocol
 
 (in-package :cleric-epmd)
 
-;;; EPMD port
-(defconstant +epmd-port+ 4369
-  "The default TCP port the EPMD listens on.")
-
 ;;; EPMD message tags
 (defconstant +port2-resp+       #\w)
 (defconstant +alive2-req+       #\x)
@@ -21,9 +17,6 @@
 
 (defconstant +protocol-tcpip4+ 0)
 
-(defvar *epmd-socket* nil
-  "The EPMD socket. NIL if not registered in EPMD.")
-
 
 ;;;
 ;;; ALIVE2_REQ
@@ -180,113 +173,3 @@
              for line = (read-line stream nil)
              while line collect line)))
 
-
-;;;
-;;; WITH-EPMD-CONNECTION-STREAM macro
-;;;
-
-(defmacro with-epmd-connection-stream
-    ((stream-var &optional (host "localhost")) &body body)
-  "Create a local scope where STREAM-VAR is a socket stream connected to the EPMD."
-  (let ((socket-var (gensym)))
-    `(let* ((,socket-var (connect-to-epmd ,host))
-            (,stream-var (usocket:socket-stream ,socket-var)))
-       (unwind-protect (progn ,@body)
-         (usocket:socket-close ,socket-var))) ))
-
-
-;;;
-;;; EPMD API
-;;;
-
-(defun publish ()
-  (if *epmd-socket*
-      (error 'already-registered)
-      (restart-case
-          (if (not (listening-p))
-              (error 'not-listening-on-socket)
-              (let* ((socket (connect-to-epmd))
-                     (epmd (usocket:socket-stream socket)))
-                (write-alive2-request
-                 epmd (node-name (this-node)) (listening-port))
-                (finish-output epmd)
-                (let ((creation (read-alive2-response epmd)))
-                  (declare (ignore creation))
-                  (setf *epmd-socket* socket)
-                  t)))
-        (start-listening-on-socket ()
-          :report "Start listening on a socket."
-          :test (lambda (c)
-                  (declare (ignore c))
-                  (not (listening-p)))
-          (start-listening)
-          (publish)))))
-
-(defun published-p ()
-  (not (null *epmd-socket*)))
-
-(defun unpublish ()
-  (when *epmd-socket*
-    (usocket:socket-close *epmd-socket*)
-    (setf *epmd-socket* nil)
-    t))
-
-(defun lookup-node (node-name &optional (host "localhost"))
-  "Query the EPMD about a node. Returns a REMOTE-NODE object that represents the node."
-  (with-epmd-connection-stream (epmd host)
-    (write-port-please2-request epmd node-name)
-    (finish-output epmd)
-    (read-port-please2-response epmd host)))
-
-(defun print-all-registered-nodes (&optional (host "localhost") (stream t))
-  "Query the EPMD about all registered nodes and print the information."
-  (with-epmd-connection-stream (epmd host)
-    (write-names-request epmd)
-    (finish-output epmd)
-    (multiple-value-bind (epmd-port node-info)
-        (read-names-response epmd)
-      (declare (ignore epmd-port))
-      (format stream "~{~a~%~}" node-info)
-      t)))
-
-
-;;;
-;;; Helper functions
-;;;
-
-(defun connect-to-epmd (&optional (host "localhost"))
-  (let ((socket (handler-case (usocket:socket-connect host
-                                                      +epmd-port+
-                                                      :element-type 'octet)
-                  (usocket:connection-refused-error ()
-                    (error 'unreachable-error))
-                  (usocket:unknown-error ()
-                    (error 'host-unknown-error)))))
-    (setf (usocket:socket-stream socket)
-          (make-flexi-stream (usocket:socket-stream socket)))
-    socket))
-
-
-;;;
-;;; Conditions
-;;;
-
-(define-condition already-registered (error)
-  ()
-  (:documentation "This error is signaled when trying to register on the EPMD when already registered."))
-
-(define-condition host-unknown-error (error)
-  ;; USOCKET:UNKNOWN-ERROR
-  ()
-  (:documentation "This error is signaled if the hostname for EPMD is unresolvable."))
-
-(define-condition unreachable-error (error)
-  ;; USOCKET:CONNECTION-REFUSED-ERROR
-  ()
-  (:documentation "This error is signaled when the EPMD is unreachable."))
-
-
-(define-condition response-error (error)
-  ;; Useful?
-  ()
-  (:documentation "This error is signaled when the EPMD sends an error response."))