#!/bin/bash

# Copyright Peter Palfrader <peter@palfrader.org>
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

if [ "$1" = "autoconf" ]; then
  echo yes
  exit 0
fi

if [ "$1" = "config" ]; then
  echo 'graph_title Postgres WAL Traffic'
  echo 'graph_args -l 0'
  echo 'graph_vlabel bytes/min'
  echo 'graph_info This graph shows amount of transaction log traffic'
  echo 'walt.label WAL Traffic'
  echo 'walt.cdef walt,60,*'
  echo 'walt.type DERIVE'
  echo 'walt.draw AREA'
  exit 0
fi


INFO=`psql -p 5433 --no-align --command 'SELECT * FROM pg_xlogfile_name_offset(pg_current_xlog_insert_location())' --field-separator ' ' --quiet | tail -n2 | head -n1`

file=`echo "$INFO" | awk '{print $1}'`
offset=`echo "$INFO" | awk '{print $2}'`

serial=`echo "$file" | cut -b 9- | sed -e s/^0*/0x/`

bytes=$(( serial * 16*1024*1024 + offset ))
echo echo "walt.value $bytes"