From b5c5e835c64f0aa51387fca574b883a4228218e9 Mon Sep 17 00:00:00 2001
From: Random Hacker <random_hacker@xapek.org>
Date: Fri, 9 Mar 2012 12:57:09 +0100
Subject: ebus-racket: inserter-pq: reconnect

---
 ebus-racket/inserter-pq.rkt | 90 +++++++++++++++++++++++++++------------------
 1 file changed, 55 insertions(+), 35 deletions(-)

diff --git a/ebus-racket/inserter-pq.rkt b/ebus-racket/inserter-pq.rkt
index 85073f4..8dc9fb8 100755
--- a/ebus-racket/inserter-pq.rkt
+++ b/ebus-racket/inserter-pq.rkt
@@ -1,12 +1,12 @@
 #! /usr/bin/env racket
 #lang racket/base
 (require racket/cmdline
-	 racket/tcp
-	 racket/match
-	 "db-pq.rkt"
-	 "layer7.rkt"
-	 "layer2.rkt"
-	 "tcp-repl.rkt")
+         racket/tcp
+         racket/match
+         "db-pq.rkt"
+         "layer7.rkt"
+         "layer2.rkt"
+         "tcp-repl.rkt")
 
 (define logger (make-logger 'ebus-inserter (current-logger)))
 
@@ -16,6 +16,15 @@
 (define loglevel-db? (make-parameter 'warning))
 (define insert? (make-parameter #f))
 
+(define (get-input-port)
+  (if (or (null? (connect-host?)) (null? (connect-port?)))
+    (begin
+      (log-message (current-logger) 'info "Using stdin" #t)
+      (current-input-port))
+    (let-values ([(cin cout) (tcp-connect (connect-host?) (connect-port?))])
+                (log-message logger 'info (format "Connected to ~s ~s" (connect-host?) (connect-port?)) #t)
+                cin)))
+
 (define (handle-fields fields)
   (for ([field fields])
        (log-message logger 'info (format "Field: ~a" field) #t)
@@ -24,17 +33,35 @@
                                       (log-message logger 'error (format "Failed to insert ~a: ~a" field exn) #t))])
            (apply db-insert-field field)))))
 
-(define (make-ebus-loop7 input-port)
-  (lambda ()
-    (let loop ()
-      (with-handlers ([exn:fail? (lambda (exn)
-                                   (log-message logger 'error (format "Failed to parse paket: ~a" exn) #t)
-                                   (loop) )])
-        (let ([fields (layer7-read-ebus (current-input-port))])
-	  (when (not (or (void? fields) (eof-object? fields)))
-	    (handle-fields fields))
-	  (when (not (eof-object? fields))
-	    (loop)))))))
+(define (read-ebus-loop7)
+  (define input-port (get-input-port))
+
+  (define (reconnect)
+    (log-message logger 'warning "Reconnect - sleep 5sec" #t)
+    (sleep 5)
+    (log-message logger 'warning "Reconnect - now" #t)
+    (set! input-port (get-input-port)))
+      
+  (let loop ()
+    (with-handlers ([exn:fail:read:eof? 
+                      (lambda (exn-eof)
+                        (log-message logger 'error (format "EOF read: ~a" exn) #t)
+                        (raise exn-eof))]; re-raise to prevent reconnect
+                    [exn:fail:network? 
+                      (lambda (exn-network)
+                        (log-message logger 'error (format "Network error: ~a" exn) #t)
+                        (reconnect))]
+                    [exn:fail? (lambda (exn)
+                                 (log-message logger 'error (format "Failed to parse paket: ~a" exn) #t))])
+      (let ([fields (layer7-read-ebus input-port)])
+        (when (eof-object? fields)
+          (raise
+            (make-exn:fail:read:eof "Read EOF from layer7" 
+                                    (current-continuation-marks)
+                                    (list))))
+        (when (not (or (void? fields) (eof-object? fields)))
+          (handle-fields fields))))
+    (loop)))
 
 ;; Start Thread that observe all given log-receivers
 (define (start-logger-thread receiver1 . receiverN)
@@ -43,12 +70,13 @@
    (thread
     (lambda ()
       (let loop ()
-	(match (apply sync receivers)
-	  [(vector level msg data)
-	   (printf "[~s] ~a~n" level msg)
-	   (flush-output)])
-	(loop))))))
+        (match (apply sync receivers)
+          [(vector level msg data)
+           (printf "[~s] ~a~n" level msg)
+           (flush-output)])
+        (loop))))))
 
+;; Marks Namespace where TCP-REPL starts
 (define-namespace-anchor repl-ns-anchor)
 
 (define (main)
@@ -77,25 +105,17 @@
 
   ;; Init Logging
   (start-logger-thread (make-log-receiver logger 'info)
-		       (make-log-receiver db-logger (loglevel-db?))
-		       (make-log-receiver layer2-logger (loglevel-layer2?))
-		       (make-log-receiver layer7-logger 'info)
-		       (make-log-receiver tcp-repl-logger 'info))
+                       (make-log-receiver db-logger (loglevel-db?))
+                       (make-log-receiver layer2-logger (loglevel-layer2?))
+                       (make-log-receiver layer7-logger 'info)
+                       (make-log-receiver tcp-repl-logger 'info))
 
   ;; Test Database Connection
   (when (not (db-pgc-test))
     (log-message logger 'fatal "Failed to connect to database" #t)
     (exit 1))
 
-  ;; Connect, replacing input with tcp connection
-  (if (or (null? (connect-host?)) (null? (connect-port?)))
-      (log-message (current-logger) 'info "Using stdin" #t)
-      (let-values ([(cin cout) (tcp-connect (connect-host?) (connect-port?))])
-	(log-message logger 'info (format "Connected to ~s ~s ~n" (connect-host?) (connect-port?)) #t)
-	(current-input-port cin)))
-
   ;; Process Ebus Packets
-  ((make-ebus-loop7 (current-input-port)) )
-  )
+  (read-ebus-loop7))
 
 (exit (main))
-- 
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