From 63d19cc87f7ea1a5888ab730394d622f58d9aa40 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lucio=20Andr=C3=A9s=20Illanes=20Albornoz?=
 <lucio@lucioillanes.de>
Date: Fri, 26 Jun 2020 02:00:46 +0100
Subject: subr/rtl_fetch.subr:rtl_fetch_url_wget(): retain digest post-download
 & forcibly re-download on mismatch (via midipix.)
 subr/rtl_complex.subr:rtl_check_digest{,_file}(): initial implementation.

---
 subr/rtl_complex.subr | 26 ++++++++++++++++++++++++++
 subr/rtl_fetch.subr   | 39 ++++++++++++++++++++-------------------
 2 files changed, 46 insertions(+), 19 deletions(-)

(limited to 'subr')

diff --git a/subr/rtl_complex.subr b/subr/rtl_complex.subr
index 63175bed..4894e0f6 100644
--- a/subr/rtl_complex.subr
+++ b/subr/rtl_complex.subr
@@ -2,6 +2,32 @@
 # set +o errexit -o noglob -o nounset is assumed.
 #
 
+rtl_check_digest() {
+	local _fname="${1}" _digest_check="${2}" _digest=""; RTL_CHECK_DIGEST_DIGEST="";
+	if ! [ -e "${_fname}" ]; then
+		return 1;
+	else	set -- $(sha256sum "${_fname}");
+		RTL_CHECK_DIGEST_DIGEST="${1}";
+		if [ "${RTL_CHECK_DIGEST_DIGEST}" = "${_digest_check}" ]; then
+			return 0;
+		else
+			return 1;
+		fi;
+	fi;
+};
+
+rtl_check_digest_file() {
+	local _fname="${1}" _digest_check="${2}" _digest_fname="${3}" _digest="" RTL_CHECK_DIGEST_DIGEST="";
+	if !  [ -e "${_digest_fname}" ]; then
+		return 1;
+	else	_digest="$(cat "${_digest_fname}")";
+		if [ "${_digest}" != "${_digest_check}" ]\
+		|| ! rtl_check_digest "${_fname}" "${_digest_check}"; then
+			return 1;
+		fi;
+	fi;
+};
+
 rtl_check_path_vars() {
 	local _vnames="${1}" _rc=0 _vname="" _vname_val=""; _status="";
 	for _vname in ${_vnames}; do
diff --git a/subr/rtl_fetch.subr b/subr/rtl_fetch.subr
index cf7e3955..350a01e8 100644
--- a/subr/rtl_fetch.subr
+++ b/subr/rtl_fetch.subr
@@ -2,7 +2,7 @@
 # set +o errexit -o noglob -o nounset is assumed.
 #
 
-exp_rtl_fetch_url_git() {
+rtlp_fetch_url_git() {
 	local _tgtdir="${1}" _subdir="${2}" _url="${3}" _branch="${4}"	\
 		_oldpwd="";
 	(set -o errexit -o noglob -o nounset;
@@ -46,34 +46,35 @@ rtl_fetch_urls_git() {
 		if [ "${_url_spec#*@}" != "${_url_spec}" ]; then
 			_git_branch=${_url_spec#*@};
 		fi;
-		exp_rtl_fetch_url_git "${_tgtdir}" "${_subdir}"	\
+		rtlp_fetch_url_git "${_tgtdir}" "${_subdir}"	\
 			"${_url}" "${_git_branch}";
 	done;
 };
 
 # N.B.	URLs ($1) may contain `?' or '&' characters.
 rtl_fetch_url_wget() {
-	local _url="${1}" _sha256sum_src="${2}" _target_fname="${3}" _sha256sum_dst="";
+	local _url="${1}" _sha256sum_src="${2}" _target_fname="${3}" _target_fname_full="" RTL_CHECK_DIGEST_DIGEST="";
 	if [ "${ARG_FETCH_FORCE}" = "offline" ]; then
 		return 0;
-	elif [ -z "${_target_fname}" ]; then
-		_target_fname="$(rtl_basename "${_url}")";
-	fi;
-	_url_dst="${BUILD_DLCACHEDIR}/${_target_fname}";
-	(set -o errexit -o noglob -o nounset;
-	rtl_flock_acquire 4 || exit "${?}";
-	trap "_rc=\"\${?}\" ;rm -f \"${_url_dst}.fetching\"; exit \"\${_rc}\";" EXIT;
-	if [ ! -e "${_url_dst}.fetched" ]; then
-		wget ${DEFAULT_WGET_ARGS} -O "${_url_dst}" "${_url}";
-		if [ -n "${_sha256sum_src}" ]; then
-			set -- $(sha256sum "${_url_dst}");
-			if [ "${_sha256sum_dst:=${1}}" != "${_sha256sum_src}" ]; then
+	else	if [ -z "${_target_fname}" ]; then
+			_target_fname="$(rtl_basename "${_url}")";
+		fi;
+		_target_fname_full="${BUILD_DLCACHEDIR}/${_target_fname}";
+		(set -o errexit -o noglob -o nounset;
+		rtl_flock_acquire 4 || exit "${?}";
+		trap "_rc=\"\${?}\"; rm -f \"${_target_fname_full}.fetching\"; exit \"\${_rc}\";" EXIT;
+		if [ -z "${_sha256sum_src}" ]\
+		|| ! rtl_check_digest_file "${_target_fname_full}" "${_sha256sum_src}" "${_target_fname_full}.fetched"; then
+			wget ${DEFAULT_WGET_ARGS} -O "${_target_fname_full}" "${_url}";
+			if [ -n "${_sha256sum_src}" ]\
+			&& ! rtl_check_digest "${_target_fname_full}" "${_sha256sum_src}"; then
 				rtl_log_msg fatalexit "Error: hash mismatch for URL \`%s' (downloaded file: %s, from build variables: %s.)"\
-						"${_url}" "${_sha256sum_dst}" "${_sha256sum_src}";
+						"${_url}" "${RTL_CHECK_DIGEST_DIGEST}" "${_sha256sum_src}";
+			else
+				printf "%s" "${RTL_CHECK_DIGEST_DIGEST}" > "${_target_fname_full}.fetched";
 			fi;
-		fi;
-		rtl_fileop touch "${_url_dst}.fetched";
-	fi;) 4<>"${_url_dst}.fetching";
+		fi;) 4<>"${_target_fname_full}.fetching";
+	fi;
 };
 
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