Add an optional caching step

If the folder .cache exists, it will be used to store the
results of newest-releases.sh (with no arguments) and
version-timestamps.sh (with particular arguments).

Subsequent executions will dump the cached content,
rather than querying the Internet again. This behavior
is useful to do local development more rapidly.

Author: ctrueden

newest-releases.sh

@@ -11,14 +11,19 @@
 
 dir=$(cd "$(dirname "$0")" && pwd)
 
+cacheFile=
+test -d .cache &&
+  cacheFile=.cache/newest-releases &&
+  test -f "$cacheFile" && cat "$cacheFile" && exit 1
+
 test "$1" &&
   pomURL=$1 ||
   pomURL=https://raw.githubusercontent.com/scijava/pom-scijava/master/pom.xml
 
 pomFile=$(mktemp -t status.scijava.org-XXXX)
 curl -fs "$pomURL" > "$pomFile"
 
-mvn -B -U -Dverbose=true -f "$pomFile" -s settings.xml \
+result=$(mvn -B -U -Dverbose=true -f "$pomFile" -s settings.xml \
   -Dmaven.version.rules=file://$dir/rules.xml \
   versions:display-dependency-updates |
   # Standardize the output format for too-long G:A strings.
@@ -32,6 +37,8 @@ mvn -B -U -Dverbose=true -f "$pomFile" -s settings.xml \
   # Catch when there is no version update.
   sed 's/ *\.\.\.\.* *\([^ ]*\) */,\1,\1/' |
   # Sort the results.
-  sort
+  sort)
+
+  echo "$result" | tee $cacheFile
 
 rm "$pomFile"

version-timestamps.sh

@@ -172,7 +172,11 @@ do
 			rest=${gav#*:}
 			a=${rest%%:*}
 			v=${rest#*:}
-			processGAV "$g" "$a" "$v"
+			cacheFile=.cache/"version-timestamps-$g-$a-$v"
+			if [ -f "$cacheFile" ]; then cat "$cacheFile"
+			elif [ -d .cache ]; then processGAV "$g" "$a" "$v" | tee "$cacheFile"
+			else processGAV "$g" "$a" "$v"
+			fi
 			;;
 		*)
 			echo "[WARNING] Ignoring invalid argument: $1" 2>&1