#!/bin/sh

# if this chart is called X.chart.sh, then all functions and global variables
# must start with X_

cpufreq_sys_dir="/sys/devices"
cpufreq_sys_depth=10
cpufreq_source_update=1

# _update_every is a special variable - it holds the number of seconds
# between the calls of the _update() function
cpufreq_update_every=
cpufreq_priority=10000

cpufreq_find_all_files() {
	find $1 -maxdepth $cpufreq_sys_depth -name scaling_cur_freq 2>/dev/null
}

# _check is called once, to find out if this chart should be enabled or not
cpufreq_check() {

	# this should return:
	#  - 0 to enable the chart
	#  - 1 to disable the chart

	[ -z "$( cpufreq_find_all_files $cpufreq_sys_dir )" ] && return 1
	return 0
}

# _create is called once, to create the charts
cpufreq_create() {
	local dir= file= id= i=

	# we create a script with the source of the
	# cpufreq_update() function
	# - the highest speed we can achieve -
	[ $cpufreq_source_update -eq 1 ] && echo >$TMP_DIR/cpufreq.sh "cpufreq_update() {"

	echo "CHART cpu.cpufreq '' 'CPU Clock' 'MHz' 'cpufreq' '' line $((cpufreq_priority + 1)) $cpufreq_update_every"
	echo >>$TMP_DIR/cpufreq.sh "echo \"BEGIN cpu.cpufreq \$1\""

	i=0
	for file in $( cpufreq_find_all_files $cpufreq_sys_dir | sort -u )
	do
		i=$(( i + 1 ))
		dir=$( dirname $file )
		cpu=

		[ -f $dir/affected_cpus ] && cpu=$( cat $dir/affected_cpus )
		[ -z "$cpu" ] && cpu="$i.a"

		id="$( fixid "cpu$cpu" )"

		echo >&2 "charts.d: cpufreq: on file='$file', dir='$dir', cpu='$cpu', id='$id'"

		echo "DIMENSION $id '$id' absolute 1 1000"
		echo >>$TMP_DIR/cpufreq.sh "printf \"SET $id = \"; cat $file "
	done
	echo >>$TMP_DIR/cpufreq.sh "echo END"

	[ $cpufreq_source_update -eq 1 ] && echo >>$TMP_DIR/cpufreq.sh "}"
	# cat >&2 $TMP_DIR/cpufreq.sh

	# ok, load the function cpufreq_update() we created
	[ $cpufreq_source_update -eq 1 ] && . $TMP_DIR/cpufreq.sh

	return 0
}

# _update is called continiously, to collect the values
cpufreq_update() {
	# the first argument to this function is the microseconds since last update
	# pass this parameter to the BEGIN statement (see bellow).

	# do all the work to collect / calculate the values
	# for each dimension
	# remember: KEEP IT SIMPLE AND SHORT

	[ $cpufreq_source_update -eq 0 ] && . $TMP_DIR/cpufreq.sh $1

	return 0
}