Hide download parallelization behind a feature flag

ALBS_PARALLELIZE_DOWNLOAD=true to enable

It doesn't seem to improve performance just load on bugs.al.org.

snapshotter.sh

 #!/bin/bash
 set -o nounset -o errexit -o pipefail
+ALBS_PARALLELIZE_DOWNLOAD="${ALBS_PARALLELIZE_DOWNLOAD:-false}"
 
 function get_newest_task_id() {
   wget --output-document=- "https://bugs.archlinux.org/index.php?project=0&status[]=&changedfrom=2021-04-01" | grep --perl-regexp --only-matching --max-count 1 "(?<=task)[0-9]+"
@@ -11,10 +12,13 @@ function generate_urls() {
 
 function _download() {
   set -o nounset -o errexit -o pipefail
-  local dir
-  dir="$(grep --only-matching "[0-9]*$" <<< "${2}")"
-  mkdir "${dir}"
-  cd "${dir}"
+
+  if [[ ${ALBS_PARALLELIZE_DOWNLOAD} = true ]]; then
+    local dir
+    dir="$(grep --only-matching "[0-9]*$" <<< "${2}")"
+    mkdir "${dir}"
+    cd "${dir}"
+  fi
 
   local include_directories="user,themes,ajax,javascript"
   if [ "${1}" = "true" ]; then
@@ -37,18 +41,24 @@ function _download() {
 }
 
 function download() {
-  export -f _download
-  time echo "${2}" | xargs --max-procs=5 --max-args=200 bash -c "_download \"${1}\" \"\${@}\""
-  mkdir final
-  for d in */; do
-    if [[ ${d} = final/ ]]; then
-      continue
-    fi
-    rsync --recursive --ignore-existing "${d}" final/
-    rm -rf "${d}"
-  done
-  mv final/* .
-  rmdir final
+  if [[ ${ALBS_PARALLELIZE_DOWNLOAD} != true ]]; then
+    mapfile -t array <<< "${2}"
+    _download "${1}" "${array[@]}"
+  else
+    # broken?
+    export -f _download
+    time echo "${2}" | xargs --max-procs=5 --max-args=200 bash -c "_download \"${1}\" \"\${@}\""
+    mkdir final
+    for d in */; do
+      if [[ ${d} = final/ ]]; then
+        continue
+      fi
+      rsync --recursive --ignore-existing "${d}" final/
+      rm -rf "${d}"
+    done
+    mv final/* .
+    rmdir final
+  fi
 }
 
 function cleanup_html() {