From 0ea0fe3528373477fff4177b9b1328c084dcaacd Mon Sep 17 00:00:00 2001
From: Ricardo Pardini <ricardo@pardini.net>
Date: Tue, 17 Jan 2023 23:48:47 +0100
Subject: [PATCH] armbian-next: `mktemp` and `tmpfs` related utility functions
 with automatic cleanup handlers

---
 lib/functions/host/mktemp-utils.sh | 65 ++++++++++++++++++++++++++++++
 lib/functions/host/tmpfs-utils.sh  | 10 +++++
 lib/library-functions.sh           |  9 +++++
 3 files changed, 84 insertions(+)
 create mode 100644 lib/functions/host/mktemp-utils.sh

diff --git a/lib/functions/host/mktemp-utils.sh b/lib/functions/host/mktemp-utils.sh
new file mode 100644
index 0000000000..c4c84db6cc
--- /dev/null
+++ b/lib/functions/host/mktemp-utils.sh
@@ -0,0 +1,65 @@
+# Those are convenience helpers for creating sub-dirs, for each usage, in WORKDIR.
+# They also setup a cleanup trap, and allow early calling of the cleanup handler.
+# Usage:
+# declare cleanup_id="" temp_dir=""
+# prepare_temp_dir_in_workdir_and_schedule_cleanup "NAME_HERE" cleanup_id temp_dir # namerefs
+# # ... do stuff with temp_dir ...
+# # at the end:
+# done_with_temp_dir "${cleanup_id}"
+function prepare_temp_dir_in_workdir_and_schedule_cleanup() {
+	declare temp_dir_id="${1}"           # gotta be unique across all concurrent invocations.
+	declare -n nameref_cleanup_id="${2}" # nameref
+	declare -n nameref_temp_dir="${3}"   # nameref
+
+	# if no WORKDIR set, or not an existing directory, bail with error
+	if [[ -z "${WORKDIR}" ]] || [[ ! -d "${WORKDIR}" ]]; then
+		exit_with_error "prepare_temp_dir_in_workdir_and_schedule_cleanup: WORKDIR is not set or not a directory: ${temp_dir_id}"
+	fi
+
+	nameref_temp_dir="$(mktemp -d)" # subject to TMPDIR/WORKDIR
+	display_alert "prepare_temp_dir_in_workdir_and_schedule_cleanup: created temp dir" "${nameref_temp_dir}" "cleanup"
+
+	chmod 700 "${nameref_temp_dir}" # does every usage need this? why?
+
+	# add the cleanup handler
+	declare -a cleanup_params=("${temp_dir_id}" "${nameref_temp_dir}")
+	nameref_cleanup_id="cleanup_temp_dir_in_workdir ${cleanup_params[*]@Q}"
+	display_alert "prepare_temp_dir_in_workdir_and_schedule_cleanup: add cleanup handler" "${nameref_cleanup_id}" "cleanup"
+	add_cleanup_handler "${nameref_cleanup_id}"
+}
+
+function done_with_temp_dir() {
+	declare cleanup_id="${1}"
+	# validate
+	if [[ -z "${cleanup_id}" ]]; then
+		exit_with_error "done_with_temp_dir: cleanup_id (arg 1) is empty"
+	fi
+
+	# just de-stack from the trap manager. this will trigger an early cleanup under normal conditions.
+	# if something fails _before_ this, then the normal trap manager will take care of it.
+	execute_and_remove_cleanup_handler "${cleanup_id}"
+}
+
+function cleanup_temp_dir_in_workdir() {
+	declare temp_dir_id="${1}"
+	declare temp_dir="${2}"
+
+	# if no WORKDIR set, or not an existing directory, bail with error
+	if [[ -z "${WORKDIR}" ]] || [[ ! -d "${WORKDIR}" ]]; then
+		display_alert "cleanup_temp_dir_in_workdir" "WORKDIR is not set or not a directory: ${temp_dir_id}" "err"
+		return 1
+	fi
+
+	# if no temp_dir set, or not an existing directory, bail with error
+	if [[ -z "${temp_dir}" ]] || [[ ! -d "${temp_dir}" ]]; then
+		exit_with_error "cleanup_temp_dir_in_workdir" "temp_dir is not set or not a directory: ${temp_dir_id}" "err"
+		return 1
+	fi
+
+	# remove the dir if we created it.
+	cd "${SRC}" || display_alert "cleanup_temp_dir_in_workdir: cd failed" "${SRC}" "err"
+	display_alert "cleanup_temp_dir_in_workdir: removing dir" "${temp_dir}" "cleanup"
+	rm -rf "${temp_dir:?}"
+
+	return 0
+}
diff --git a/lib/functions/host/tmpfs-utils.sh b/lib/functions/host/tmpfs-utils.sh
index 2367559c44..f09b8e69d9 100644
--- a/lib/functions/host/tmpfs-utils.sh
+++ b/lib/functions/host/tmpfs-utils.sh
@@ -91,3 +91,13 @@ function cleanup_tmpfs_for() {
 
 	return 0
 }
+
+# Debugging utility.
+function debug_tmpfs_show_usage() {
+	if [[ "${SHOW_TMPFS}" == "yes" ]]; then
+		display_alert "TMPFS debugging:" "${CURRENT_LOGGING_SECTION:-none} $*" "debug"
+		run_host_command_logged df -h -t tmpfs "||" true
+		run_host_command_logged free -m "||" true
+	fi
+	return 0
+}
diff --git a/lib/library-functions.sh b/lib/library-functions.sh
index c97dd62a16..7004fe879b 100644
--- a/lib/library-functions.sh
+++ b/lib/library-functions.sh
@@ -532,6 +532,15 @@ set -o errexit  ## set -e : exit the script if any statement returns a non-true
 # shellcheck source=lib/functions/host/host-utils.sh
 source "${SRC}"/lib/functions/host/host-utils.sh
 
+# no errors tolerated. invoked before each sourced file to make sure.
+#set -o pipefail  # trace ERR through pipes - will be enabled "soon"
+#set -o nounset   ## set -u : exit the script if you try to use an uninitialised variable - one day will be enabled
+set -o errtrace # trace ERR through - enabled
+set -o errexit  ## set -e : exit the script if any statement returns a non-true return value - enabled
+### lib/functions/host/mktemp-utils.sh
+# shellcheck source=lib/functions/host/mktemp-utils.sh
+source "${SRC}"/lib/functions/host/mktemp-utils.sh
+
 # no errors tolerated. invoked before each sourced file to make sure.
 #set -o pipefail  # trace ERR through pipes - will be enabled "soon"
 #set -o nounset   ## set -u : exit the script if you try to use an uninitialised variable - one day will be enabled