Eventscript functions - optimise is_ctdb_managed_service().

This function generates a lot of trace when running under "set -x".
This is due to the backward compatibility code.

This adds 3 optimisations:

1. Before invoking the backward compatiblity code,
   is_ctdb_managed_service() returns early if the service is listed in
   $CTDB_MANAGED_SERVICES.

2. ctdb_compat_managed_service() actually now updates
   $CTDB_MANAGED_SERVICES instead of temporary variable $t.

   This means that a subsequent call to is_ctdb_managed_service() will
   short circuit due to optimisation (1).

3. ctdb_compat_managed_service() only adds a service to
   $CTDB_MANAGED_SERVICES if it is the service being checked by
   is_ctdb_managed_service().

   This stops irrelevant services being added to
   $CTDB_MANAGED_SERVICES multiple times by multiple calls to
   is_ctdb_managed_service().

Signed-off-by: Martin Schwenke <martin@meltin.net>

(This used to be ctdb commit 758f4667c60089e09a0439c1eb74f5e426ca5e2e)

1 files changed, 14 insertions, 3 deletions

diff --git a/ctdb/config/functions b/ctdb/config/functions
index 32f11f0690..5c414585ca 100755
--- a/ctdb/config/functions
+++ b/ctdb/config/functions
@@ -669,8 +669,8 @@ ctdb_service_reconfigure ()
 
 ctdb_compat_managed_service ()
 {
-    if [ "$1" = "yes" ] ; then
-	t="$t $2 "
+    if [ "$1" = "yes" -a "$2" = "$_service_name" ] ; then
+	CTDB_MANAGED_SERVICES="$CTDB_MANAGED_SERVICES $2"
     fi
 }
 
@@ -678,8 +678,17 @@ is_ctdb_managed_service ()
 {
     _service_name="${1:-${service_name}}"
 
+    # $t is used just for readability and to allow better accurate
+    # matching via leading/trailing spaces
     t=" $CTDB_MANAGED_SERVICES "
 
+    # Return 0 if "<space>$_service_name<space>" appears in $t
+    if [ "${t#* ${_service_name} }" != "${t}" ] ; then
+	return 0
+    fi
+
+    # If above didn't match then update $CTDB_MANAGED_SERVICES for
+    # backward compatibility and try again.
     ctdb_compat_managed_service "$CTDB_MANAGES_VSFTPD"   "vsftpd"
     ctdb_compat_managed_service "$CTDB_MANAGES_SAMBA"    "samba"
     ctdb_compat_managed_service "$CTDB_MANAGES_SCP"      "scp"
@@ -690,7 +699,9 @@ is_ctdb_managed_service ()
     ctdb_compat_managed_service "$CTDB_MANAGES_NFS"      "nfs"
     ctdb_compat_managed_service "$CTDB_MANAGES_NFS"      "nfs-ganesha-gpfs"
 
-    # Returns 0 if "<space>$_service_name<space>" appears in $t
+    t=" $CTDB_MANAGED_SERVICES "
+
+    # Return 0 if "<space>$_service_name<space>" appears in $t
     [ "${t#* ${_service_name} }" != "${t}" ]
 }