Caching of `setup-environment-commands` using Dorothy User Configuration's `$DOROTHY/user/config/envrionment.bash`

environment.bash

#!/usr/bin/env bash

cache_validity_seconds=600 # six hundred seconds in ten minutes
cache_checksum_tool='/opt/homebrew/bin/xxhsum' # xxhsum and b2sum are equivalent in speed, then openssl sha256, then b3sum
if [[ -n "$cache_validity_seconds" && -x "$cache_checksum_tool" ]]; then
	ppid=$$
	now_env="$(env -u TERM_SESSION_ID | sort)"
	context_id="$shell-$("$cache_checksum_tool" <<<"$now_env" | cut -f1 -d ' ')"
	lock_file="$XDG_CACHE_HOME/dorothy-environment-$context_id.lock" # this file is the process id that has the lock
	result_file="$XDG_CACHE_HOME/dorothy-environment-$context_id.result" # this file is the environment modifications for the environment vars we are valid for
	# wait for a exclusive lock
	while :; do
		# don't bother with a [[ -s "$lock_file" ]] before [cat] as the lock_file could have been removed between
		wait="$(cat "$lock_file" 2>/dev/null || :)"
		if [[ -z "$wait" ]]; then
			__print_string "$ppid" >"$lock_file"
		elif [[ "$wait" == "$ppid" ]]; then
			break
		fi
		sleep "0.01$RANDOM"
	done
	# if cache is available and applicable
	if [[ -f "$result_file" ]]; then
		# if cache is still valid
		now_seconds="$(date +%s)"
		cache_seconds="$(date -r "$result_file" +%s)"
		cache_ago_seconds="$((now_seconds - cache_seconds))"
		if [[ "$cache_ago_seconds" -lt "$cache_validity_seconds" ]]; then
			# then use the cache
			trap - EXIT # remove the prior trap, as we are using our cache result, rather than a new env.bash result
			cat "$result_file"
			rm -f "$lock_file"
			exit
		else
			: # __print_lines 'CACHE INVALIDATED' >/dev/tty
		fi
	else
		: # __print_lines 'CACHE NOT FOUND' >/dev/tty
	fi
	# cache needs updating
	function on_env_finish_cache {
		local status=$?
		if [[ $status -ne 0 ]]; then
			rm -f "$lock_file"
			return $status
		fi
		# store the result
		on_env_finish | tee "$result_file" || {
			status=$?
			rm -f "$lock_file"
			return $status
		}
		rm -f "$lock_file"
		return 0
	}
	trap on_env_finish_cache EXIT # replace our prior trap with one that caches the result
fi