From e941c0672e8db8028a0bafd9257d146cd5c2ef9c Mon Sep 17 00:00:00 2001
From: =?utf8?q?Michal=20Voc=C5=AF?= <michal@ruk.cuni.cz>
Date: Tue, 28 Jun 2005 11:02:19 +0000
Subject: [PATCH] * take the file seeking business more seriously - refuse to
 seek into the   middle of event string

---
 org.glite.lb.logger/src/event_store.c | 88 ++++++++++++++++++++++++++---------
 1 file changed, 67 insertions(+), 21 deletions(-)

diff --git a/org.glite.lb.logger/src/event_store.c b/org.glite.lb.logger/src/event_store.c
index 3ee97f3..9f56219 100644
--- a/org.glite.lb.logger/src/event_store.c
+++ b/org.glite.lb.logger/src/event_store.c
@@ -343,29 +343,74 @@ event_store_recover(struct event_store *es)
 	  return(-1);
   }
 
-  /* get the position in file to be sought */
-  if(es->offset)
-    last = es->offset;
-  else {
+  while(1) { /* try, try, try */
+
+	  /* get the position in file to be sought */
+	  if(es->offset)
+		  last = es->offset;
+	  else {
 #if !defined(IL_NOTIFICATIONS)
-    if(eq_b == eq_l) 
-      last = es->last_committed_ls;
-    else
+		  if(eq_b == eq_l) 
+			  last = es->last_committed_ls;
+		  else
 #endif
-      /* last = min(ls, bs) */
-      last = (es->last_committed_bs < es->last_committed_ls) ? es->last_committed_bs : es->last_committed_ls;
-  }
-
-  il_log(LOG_DEBUG, "    setting starting file position to  %ld\n", last);
-  il_log(LOG_DEBUG, "    bytes sent to logging server: %d\n", es->last_committed_ls);
-  il_log(LOG_DEBUG, "    bytes sent to bookkeeping server: %d\n", es->last_committed_bs);
+			  /* last = min(ls, bs) */
+			  /* I took the liberty to optimize this,
+			     since LS is not used. */
+			  /* last = (es->last_committed_bs <
+			     es->last_committed_ls) ? es->last_committed_bs :
+			     es->last_committed_ls; */
+			  last = es->last_committed_bs;
+	  }
 
-  /* skip all committed or already enqueued events */
-  if(fseek(ef, last, SEEK_SET) < 0) {
-    set_error(IL_SYS, errno, "event_store_recover: error setting position for read");
-    event_store_unlock(es);
-    fclose(ef);
-    return(-1);
+	  il_log(LOG_DEBUG, "    setting starting file position to  %ld\n", last);
+	  il_log(LOG_DEBUG, "    bytes sent to logging server: %d\n", es->last_committed_ls);
+	  il_log(LOG_DEBUG, "    bytes sent to bookkeeping server: %d\n", es->last_committed_bs);
+
+	  if(last > 0) {
+		  int c;
+
+		  /* skip all committed or already enqueued events */
+		  /* be careful - check, if the offset really points to the
+		     beginning of event string */
+		  if(fseek(ef, last-1, SEEK_SET) < 0) {
+			  set_error(IL_SYS, errno, "event_store_recover: error setting position for read");
+			  event_store_unlock(es);
+			  fclose(ef);
+			  return(-1);
+		  }
+		  /* the last enqueued event MUST end with EVENT_SEPARATOR,
+		     even if the offset points at EOF */
+		  if((c=fgetc(ef)) != EVENT_SEPARATOR) {
+			  /* Houston, we have got a problem */
+			  il_log(LOG_WARNING, 
+				 "    file position %ld does not point at the beginning of event string, backing off!\n",
+				 last);
+			  /* now, where were we? */
+			  if(es->offset) {
+				  /* next try will be with
+				     last_commited_bs */
+				  es->offset = 0;
+			  } else {
+				  /* this is really weird... back off completely */
+				  es->last_committed_ls = es->last_committed_bs = 0;
+			  }
+		  } else {
+			  /* OK, break out of the loop */
+			  break;
+		  }
+	  } else {
+		  /* this breaks out of the loop, we are starting at
+		   * the beginning of file
+		   */
+		  if(fseek(ef, 0, SEEK_SET) < 0) {
+			  set_error(IL_SYS, errno, "event_store_recover: error setting position for read");
+			  event_store_unlock(es);
+			  fclose(ef);
+			  return(-1);
+		  }
+		  break;
+	  }
   }
 
   /* enqueue all remaining events */
@@ -383,7 +428,8 @@ event_store_recover(struct event_store *es)
     msg = server_msg_create(event_s, last);
     free(event_s);
     if(msg == NULL) {
-      break;
+	    il_log(LOG_ALERT, "    event file corrupted! Please move it to quarantine (ie. somewhere else) and restart interlogger.\n");
+	    break;
     }
     msg->es = es;
 
-- 
1.8.2.3