Added `contrib/add_rra.sh' which allows to add an very detailed RRA to old RRD files.

diff --git a/contrib/add_rra.sh b/contrib/add_rra.sh
new file mode 100755 (executable)
index 0000000..c9306b0
--- /dev/null
+++ b/contrib/add_rra.sh
@@ -0,0 +1,67 @@
+#!/bin/bash
+
+INPUT=$1
+OUTPUT=$2
+
+if [ -z "$INPUT" -o -z "$OUTPUT" ]
+then
+       cat <<USAGE
+Usage: $0 <input> <output>
+USAGE
+       exit 1
+fi
+
+if [ ! -e "$INPUT" ]
+then
+       echo "No such file: $INPUT"
+       exit 1
+fi
+
+if [ -e "$OUTPUT" ]
+then
+       echo "File exists: $OUTPUT"
+       exit 1
+fi
+
+NUM_DS=0
+rrdtool dump "$INPUT" | while read LINE
+do
+       echo "$LINE"
+
+       if [ "$LINE" = "<ds>" ]
+       then
+               NUM_DS=$(($NUM_DS + 1))
+       fi
+       
+       if [ "$LINE" = "<!-- Round Robin Archives -->" ]
+       then
+               for CF in MIN MAX AVERAGE
+               do
+                       cat <<RRA
+       <rra>
+               <cf> $CF </cf>
+               <pdp_per_row> 1 </pdp_per_row>
+               <xff> 0.0000000000e+00 </xff>
+
+               <cdp_prep>
+RRA
+                       for ((i=0; i < $NUM_DS; i++))
+                       do
+                               echo "                  <ds><value> NaN </value>  <unknown_datapoints> 1 </unknown_datapoints></ds>"
+                       done
+                       echo "          </cdp_prep>"
+                       echo "          <database>"
+
+                       DS_VALUES=`for ((i=0; i < $NUM_DS; i++)); do echo -n "<v> NaN </v>"; done`
+                       for ((i=0; i < 2200; i++))
+                       do
+                               echo "                  <!-- $i --> <row>$DS_VALUES</row>"
+                       done
+                       echo "          </database>"
+                       echo "  </rra>"
+               done
+       fi
+done >"$OUTPUT.xml"
+
+rrdtool restore "$OUTPUT.xml" "$OUTPUT" -r >/dev/null
+rm -f "$OUTPUT.xml"