1 files changed, 89 insertions, 50 deletions
diff --git a/sfeed_update b/sfeed_update
index ba9e242..fd468a5 100755
--- a/sfeed_update
+++ b/sfeed_update
@@ -7,7 +7,7 @@ sfeedpath="$HOME/.sfeed/feeds"
 
 # used for processing feeds concurrently: wait until ${maxjobs} amount of
 # feeds are finished at a time.
-maxjobs=8
+maxjobs=16
 
 # load config (evaluate shellscript).
 # loadconfig(configfile)
@@ -16,26 +16,33 @@ loadconfig() {
 	if [ "$1" != "" ]; then
 		# get absolute path of config file required for including.
 		config="$1"
-		path=$(readlink -f "${config}" 2>/dev/null)
+		configpath=$(readlink -f "${config}" 2>/dev/null)
 	else
 		# default config location.
 		config="$HOME/.sfeed/sfeedrc"
-		path="${config}"
+		configpath="${config}"
 	fi
 
 	# config is loaded here to be able to override $sfeedpath or functions.
-	if [ -r "${path}" ]; then
-		. "${path}"
+	if [ -r "${configpath}" ] && [ -f "${configpath}" ]; then
+		. "${configpath}"
 	else
-		echo "Configuration file \"${config}\" cannot be read." >&2
-		echo "See sfeedrc.example for an example." >&2
-		exit 1
+		printf "Configuration file \"%s\" cannot be read.\n" "${config}" >&2
+		echo "See the sfeedrc.example file or the sfeedrc(5) man page for an example." >&2
+		die
 	fi
 }
 
 # log(name, s)
 log() {
+	printf '[%s] %-50.50s %s\n' "$(date +'%H:%M:%S')" "$1" "$2"
+}
+
+# log_error(name, s)
+log_error() {
 	printf '[%s] %-50.50s %s\n' "$(date +'%H:%M:%S')" "$1" "$2" >&2
+	# set error exit status indicator for parallel jobs.
+	rm -f "${sfeedtmpdir}/ok"
 }
 
 # fetch a feed via HTTP/HTTPS etc.
@@ -64,7 +71,7 @@ parse() {
 }
 
 # filter fields.
-# filter(name)
+# filter(name, url)
 filter() {
 	cat
 }
@@ -76,9 +83,9 @@ merge() {
 }
 
 # order by timestamp (descending).
-# order(name)
+# order(name, url)
 order() {
-	sort -t '	' -k1rn,1
+	sort -t '	' -k1rn,1 2>/dev/null
 }
 
 # internal handler to fetch and process a feed.
@@ -91,101 +98,111 @@ _feed() {
 
 	filename="$(printf '%s' "${name}" | tr '/' '_')"
 	sfeedfile="${sfeedpath}/${filename}"
-	tmpfeedfile="${sfeedtmpdir}/${filename}"
+	tmpfeedfile="${sfeedtmpdir}/feeds/${filename}"
 
 	# if file does not exist yet create it.
 	[ -e "${sfeedfile}" ] || touch "${sfeedfile}" 2>/dev/null
 
 	if ! fetch "${name}" "${feedurl}" "${sfeedfile}" > "${tmpfeedfile}.fetch"; then
-		log "${name}" "FAIL (FETCH)"
-		return
+		log_error "${name}" "FAIL (FETCH)"
+		return 1
 	fi
 
 	# try to detect encoding (if not specified). if detecting the encoding fails assume utf-8.
 	[ "${encoding}" = "" ] && encoding=$(sfeed_xmlenc < "${tmpfeedfile}.fetch")
 
 	if ! convertencoding "${name}" "${encoding}" "utf-8" < "${tmpfeedfile}.fetch" > "${tmpfeedfile}.utf8"; then
-		log "${name}" "FAIL (ENCODING)"
-		return
+		log_error "${name}" "FAIL (ENCODING)"
+		return 1
 	fi
 	rm -f "${tmpfeedfile}.fetch"
 
 	# if baseurl is empty then use feedurl.
 	if ! parse "${name}" "${feedurl}" "${basesiteurl:-${feedurl}}" < "${tmpfeedfile}.utf8" > "${tmpfeedfile}.tsv"; then
-		log "${name}" "FAIL (PARSE)"
-		return
+		log_error "${name}" "FAIL (PARSE)"
+		return 1
 	fi
 	rm -f "${tmpfeedfile}.utf8"
 
-	if ! filter "${name}" < "${tmpfeedfile}.tsv" > "${tmpfeedfile}.filter"; then
-		log "${name}" "FAIL (FILTER)"
-		return
+	if ! filter "${name}" "${feedurl}" < "${tmpfeedfile}.tsv" > "${tmpfeedfile}.filter"; then
+		log_error "${name}" "FAIL (FILTER)"
+		return 1
 	fi
 	rm -f "${tmpfeedfile}.tsv"
 
 	# new feed data is empty: no need for below stages.
 	if [ ! -s "${tmpfeedfile}.filter" ]; then
 		log "${name}" "OK"
-		return
+		return 0
 	fi
 
 	if ! merge "${name}" "${sfeedfile}" "${tmpfeedfile}.filter" > "${tmpfeedfile}.merge"; then
-		log "${name}" "FAIL (MERGE)"
-		return
+		log_error "${name}" "FAIL (MERGE)"
+		return 1
 	fi
 	rm -f "${tmpfeedfile}.filter"
 
-	if ! order "${name}" < "${tmpfeedfile}.merge" > "${tmpfeedfile}.order"; then
-		log "${name}" "FAIL (ORDER)"
-		return
+	if ! order "${name}" "${feedurl}" < "${tmpfeedfile}.merge" > "${tmpfeedfile}.order"; then
+		log_error "${name}" "FAIL (ORDER)"
+		return 1
 	fi
 	rm -f "${tmpfeedfile}.merge"
 
 	# copy
 	if ! cp "${tmpfeedfile}.order" "${sfeedfile}"; then
-		log "${name}" "FAIL (COPY)"
-		return
+		log_error "${name}" "FAIL (COPY)"
+		return 1
 	fi
 	rm -f "${tmpfeedfile}.order"
 
 	# OK
 	log "${name}" "OK"
+	return 0
 }
 
 # fetch and process a feed in parallel.
 # feed(name, feedurl, [basesiteurl], [encoding])
 feed() {
-	# wait until ${maxjobs} are finished: will stall the queue if an item
-	# is slow, but it is portable.
-	[ ${signo} -ne 0 ] && return
-	[ $((curjobs % maxjobs)) -eq 0 ] && wait
-	[ ${signo} -ne 0 ] && return
-	curjobs=$((curjobs + 1))
-
-	_feed "$@" &
+	# Output job parameters for xargs.
+	# Specify fields as a single parameter separated by a NUL byte.
+	# The parameter is split into fields later by the child process, this
+	# allows using xargs with empty fields across many implementations.
+	printf '%s\037%s\037%s\037%s\037%s\037%s\0' \
+		"${config}" "${sfeedtmpdir}" "$1" "$2" "$3" "$4"
 }
 
+# cleanup()
 cleanup() {
 	# remove temporary directory with feed files.
 	rm -rf "${sfeedtmpdir}"
 }
 
+# die(statuscode)
+die() {
+	statuscode="${1:-1}" # default: exit 1
+	# cleanup temporary files etc.
+	cleanup
+	exit "${statuscode}"
+}
+
+# sighandler(signo)
 sighandler() {
 	signo="$1"
 	# ignore TERM signal for myself.
 	trap -- "" TERM
-	# kill all running childs >:D
+	# kill all running children >:D
 	kill -TERM -$$
 }
 
+# feeds()
 feeds() {
-	echo "Configuration file \"${config}\" is invalid or does not contain a \"feeds\" function." >&2
+	printf "Configuration file \"%s\" is invalid or does not contain a \"feeds\" function.\n" "${config}" >&2
 	echo "See sfeedrc.example for an example." >&2
+	die
 }
 
+# main(args...)
 main() {
-	# job counter.
-	curjobs=0
 	# signal number received for parent.
 	signo=0
 	# SIGINT: signal to interrupt parent.
@@ -195,18 +212,40 @@ main() {
 	# load config file.
 	loadconfig "$1"
 	# fetch feeds and store in temporary directory.
-	sfeedtmpdir="$(mktemp -d '/tmp/sfeed_XXXXXX')"
+	sfeedtmpdir="$(mktemp -d "${TMPDIR:-/tmp}/sfeed_XXXXXX")" || die
+	mkdir -p "${sfeedtmpdir}/feeds"
+	touch "${sfeedtmpdir}/ok" || die
 	# make sure path exists.
 	mkdir -p "${sfeedpath}"
-	# fetch feeds specified in config file.
-	feeds
-	# wait till all feeds are fetched (concurrently).
-	[ ${signo} -eq 0 ] && wait
-	# cleanup temporary files etc.
-	cleanup
+
+	# print feeds for parallel processing with xargs.
+	feeds > "${sfeedtmpdir}/jobs" || die
+	SFEED_UPDATE_CHILD="1" xargs -x -0 -P "${maxjobs}" -n 1 \
+		"$(readlink -f "${argv0}")" < "${sfeedtmpdir}/jobs"
+	statuscode=$?
+
+	# check error exit status indicator for parallel jobs.
+	[ -f "${sfeedtmpdir}/ok" ] || statuscode=1
 	# on signal SIGINT and SIGTERM exit with signal number + 128.
-	[ ${signo} -ne 0 ] && exit $((signo+128))
-	return 0
+	[ ${signo} -ne 0 ] && die $((signo+128))
+	die ${statuscode}
 }
 
+# process a single feed.
+# parameters are: config, tmpdir, name, feedurl, basesiteurl, encoding
+if [ "${SFEED_UPDATE_CHILD}" = "1" ]; then
+	IFS="" # "\037"
+	[ "$1" = "" ] && exit 0 # must have an argument set
+	printf '%s\n' "$1" | \
+	while read -r _config _tmpdir _name _feedurl _basesiteurl _encoding; do
+		loadconfig "${_config}"
+		sfeedtmpdir="${_tmpdir}"
+		_feed "${_name}" "${_feedurl}" "${_basesiteurl}" "${_encoding}"
+		exit "$?"
+	done
+	exit 0
+fi
+
+# ...else parent mode:
+argv0="$0" # store $0, in the zsh shell $0 is the name of the function.
 [ "${SFEED_UPDATE_INCLUDE}" = "1" ] || main "$@"