utils.sh

# This file contains functions required by other nginx-rtmp-backup scripts

die() { # Exit with the proper stderr output
	echo "$CURRENT_APPLICATION_NAME: $*" >&2
	exit 1
}

parse_argv() {	# Checks that the streamname for scripts is provided
				# and set the variable
	[ "$#" -ge 1 ] || die "too few arguments"
	STREAMNAME=$1
}

pid_for() { # Gets a pid, according to stream kind (main/backup) and streamname
	echo "$PIDS_FOLDER/$1_$STREAMNAME.pid"
}

is_running() {	# Checks if the process pushing stream
				# of provided kind (main/backup) is running
	pidfile="$(pid_for "$1")"
	echo $pidfile
	[ -r "$pidfile" ] && pgrep --pidfile "$pidfile"
}

get_var() { # Gets variable value by its name
	eval echo "$"$1""
}

kill() {	# Kills a process pushing stream of provided kind (main/backup)
			# if it is running and removes its pidfile
	if is_running "$1"; then
		pidfile="$(pid_for "$1")"
	echo "got pidfile for killing"
		/bin/kill -9 "$(cat "$pidfile")" > /dev/null
		rm -f "$pidfile"
	fi
}

assert_one_of() { # Checks that the value for a variable provided in config is rigth
	varname="$1"; shift # Get variable name and remove it from arguments list
	value="$(get_var $varname)"
	expected="$*" # Values left in arguments list are expected values

	while [ "$#" -gt 0 ]; do
		if [ "$value" = "$1" ]; then return; fi # If a value of the varibale is one of the expected, return
		shift
	done

	# If we are here, the variable value do not match any of expected, exit
	die "unexpected value \`$value' for \`$varname' (expected one of '$expected')"
}

push_stream() { # Starts pushing stream
	stream_kind="$1" # backup or main
	# Get a value of either $MAIN_STREAM_NAME or $BACKUP_STREAM_NAME
	appname="$(get_var "$(echo "${stream_kind}_STREAM_APPNAME" | tr '[:lower:]' '[:upper:]')")"

	LOGFILE="$LOGS_FOLDER/${appname}_${STREAMNAME}.log"

	assert_one_of RUNNER gst avconv ffmpeg

	if [ "$RUNNER" = "gst" ]; then
		nohup gst-launch-1.0 \
			rtmpsrc location="rtmp://localhost/$appname/$STREAMNAME" do-timestamp=true ! queue ! flvdemux name=demux \
			flvmux name=mux \
			demux.video ! queue ! mux.video \
			demux.audio ! queue ! mux.audio \
			mux.src ! queue ! rtmpsink location="rtmp://localhost/$OUT_STREAM_APPNAME/$STREAMNAME" \
			\
			</dev/null \
			>"$LOGFILE" \
			2>&1 \
			&
	else
		nohup "$RUNNER" \
			-re -i "rtmp://localhost/$appname/$STREAMNAME" \
			-c copy -f flv \
			"rtmp://localhost/$OUT_STREAM_APPNAME/$STREAMNAME" \
			\
			</dev/null \
			>"$LOGFILE" \
			2>&1 \
			&
 	fi

	echo $! > "$(pid_for "$stream_kind")"
}