#!/bin/sh
#
# Check for installed MySLQ configruration and upgrade as needed.
#
# If a custom MySQL configuration is not installed in the system, install 
# the appropriate sample configuration as the default.  The sample
# configuration selected is based on the system memory size:
#   If memory size is...   Default configuration is....
#      less than 1GB         /usr/share/mysql/my-large.cnf
#      1GB or more           /usr/share/mysql/my-huge.cnf
#

__cnfname="my.cnf"
__defcnfname="${__cnfname}.default"
__altcnfdir="/usr/share/mysql"
__hugecnf="${__altcnfdir}/my-huge.cnf"
__largecnf="${__altcnfdir}/my-large.cnf"
__destdir="/etc"
__homedir="/var/root"

__progname=`/usr/bin/basename ${0}`
__datadir=`/usr/libexec/mysqld --verbose --help | grep datadir | grep \/ | sed s/datadir\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ //`

# check for presence of existing MySQL config file
__found=0
__cnfdirs="${__destdir} ${__datadir} ${__homedir}"
for __cnfdir in ${__cnfdirs}; do
   if ( test -e "${__cnfdir}/${__cnfname}" ); then
      __oldcnf="${__cnfdir}/${__cnfname}"
	  __found=1
	  break
   fi
done
if ( test ${__found} == 1 ); then
   __newcnf="${__defcnfname}"
else
   __newcnf="${__cnfname}"
fi

# check if this has already been done before
if ( test -e "${__destdir}/${__newcnf}" ); then
   exit
fi

# check if the required resources are present
if ( ! test -e "${__altcnfdir}" ); then
   logger -t ${__progname} "Error -- unable to upgrade MySQL configuration.  Required directory ${__altcnfdir} cannot be found."
   exit
fi

# determine the installed memory
__memsize=`sysctl hw.memsize | sed s/hw\.memsize\:\ //`
if ( test ${__memsize} -lt 1073741824 ); then
   __altcnf="${__largecnf}"
else
   __altcnf="${__hugecnf}"
fi

# just one more check to see if we've already done this before
if ( test -e "${__destdir}/${__cnfname}" ); then
   __diff=`diff "${__destdir}/${__cnfname}" "${__altcnf}"`
   if ( test -z "${__diff}" ); then
	  exit
   fi
fi

# install the selected configuration
cp ${__altcnf} ${__destdir}/${__newcnf}
chown mysql:admin ${__destdir}/${__newcnf}
chmod 750 ${__destdir}/${__newcnf}
logger -t ${__progname} "A new MySQL configuration (${__destdir}/${__newcnf}) has been installed to improve performance."
if ( test "${__newcnf}" == "${__defcnfname}" ); then
   logger -t ${__progname} "WARNING -- The previous MySQL configuration (${__oldcnf}) is still in effect. "
   logger -t ${__progname} "To activate the new MySLQ settings, rename ${__destdir}/${__defcnfname}"
   logger -t ${__progname} "to ${__destdir}/${__cnfname} and restart the MySQL service."
fi
exit