From 04b8036e32c42f70f316514fc3c71a79a8e51cd6 Mon Sep 17 00:00:00 2001
From: MilhouseVH <milhouseVH.github@nmacleod.com>
Date: Wed, 29 May 2019 00:49:26 +0100
Subject: [PATCH] buildsystem: replace $(cat file) with faster alternative

See: https://www.gnu.org/software/bash/manual/html_node/Command-Substitution.html

"
...
Bash performs the expansion by executing command in a subshell environment and replacing
the command substitution with the standard output of the command, with any trailing newlines
deleted. Embedded newlines are not deleted, but they may be removed during word splitting. The
command substitution $(cat file) can be replaced by the equivalent but faster $(< file).
"

Testing indicates var=$(< file) is twice as fast as var=$(cat file).
---
 config/functions   | 6 +++---
 config/multithread | 3 ++-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/config/functions b/config/functions
index af1020e884..2c5529b70f 100644
--- a/config/functions
+++ b/config/functions
@@ -1264,7 +1264,7 @@ pkg_lock() {
 
   # As we now have the lock, if .failed still exists then a previous process must have failed
   if [ -f "${THREAD_CONTROL}/locks/${pkg}.${task}.failed" ]; then
-    fail_seq="$(cat "${THREAD_CONTROL}/locks/${pkg}.${task}.failed")"
+    fail_seq="$(< "${THREAD_CONTROL}/locks/${pkg}.${task}.failed")"
     print_color CLR_ERROR "FAILURE: ${pkg}.${task}.failed exists, a previous dependency process has failed (seq: ${fail_seq})\n"
     if [ -d "${THREAD_CONTROL}/logs" ]; then
 cat <<EOF
@@ -1325,12 +1325,12 @@ update_dashboard() {
   num=$(cat "${THREAD_CONTROL}/status" | wc -l)
   while [ ${num} -lt ${sedline} ]; do echo "" >>"${THREAD_CONTROL}/status"; num=$((num + 1)); done
 
-  num=$(($(cat "${THREAD_CONTROL}/progress.prev") + 1))
+  num=$(< "${THREAD_CONTROL}/progress.prev")
   projdevarch="${PROJECT}/"
   [ -n "${DEVICE}" ] && projdevarch+="${DEVICE}/"
   projdevarch+="${TARGET_ARCH}"
   TZ=UTC0 printf -v elapsed "%(%H:%M:%S)T" $(($(date +%s) - MTBUILDSTART))
-  printf -v preamble "%s Dashboard (%s) - %d of %d jobs completed, %s elapsed" "${DISTRONAME}" "${projdevarch}" ${num} ${MTMAXJOBS} "${elapsed}"
+  printf -v preamble "%s Dashboard (%s) - %d of %d jobs completed, %s elapsed" "${DISTRONAME}" "${projdevarch}" $((num + 1)) ${MTMAXJOBS} "${elapsed}"
   printf -v preamble "%b%-105s %s" "\e[2J\e[0;0H" "${preamble//\//\\/}" "$(date "+%Y-%m-%d %H:%M:%S")"
 
   if [ "${DISABLE_COLORS}" != "yes" ]; then
diff --git a/config/multithread b/config/multithread
index cb96bfa574..902c6f5a83 100644
--- a/config/multithread
+++ b/config/multithread
@@ -107,8 +107,9 @@ package_worker() {
   (
     flock --exclusive 95
     [ ${result} -eq 0 ] && status="DONE" || status="FAIL"
-    num=$(($(cat "${THREAD_CONTROL}/progress") + 1))
+    num=$(< "${THREAD_CONTROL}/progress")
     mv "${THREAD_CONTROL}/progress" "${THREAD_CONTROL}/progress.prev"
+    num=$((num + 1))
     echo ${num} >"${THREAD_CONTROL}/progress"
     printf "[%0*d/%0*d] [%-4s] %-7s %s\n" ${#jobs} ${num} ${#jobs} ${jobs} "${status}" "${task}" "${pkgname}" >&2
   ) 95>"${THREAD_CONTROL}/locks/.progress"