From 3eebb5438bcf2118fa6a131c2cf06a61c8b36553 Mon Sep 17 00:00:00 2001
From: curt mayer <curt@zen-room.org>
Date: Sat, 22 Feb 2020 19:04:00 -0800
Subject: [PATCH] added directory mapping cache.  if the same directory is
 being hit as last run, we don't need to rebuild the map.  will likely break
 if you are running more than one at a time, in that the cache will be
 ineffective.  also, if the directory contents change, this will also break.

---
 Tools/unix/casefn.sh | 65 ++++++++++++++++++++++++++++----------------
 1 file changed, 41 insertions(+), 24 deletions(-)

diff --git a/Tools/unix/casefn.sh b/Tools/unix/casefn.sh
index 5bade162..dc16bd2e 100755
--- a/Tools/unix/casefn.sh
+++ b/Tools/unix/casefn.sh
@@ -4,15 +4,19 @@
 #
 # we don't handle files with embedded spaces, a horrible idea anyway
 #
-search=/tmp/cn.search.$$
-all=/tmp/cn.all.$$
-in=/tmp/cn.in.$$
+# this is a bit slow with lots of files, so there's a cache of the join file
+#
+pid=.$$
+search=/tmp/casefn.search$pid
+join=/tmp/casefn.join$pid
+in=/tmp/casefn.in$pid
+cache=/tmp/casefn.cache
 
 function cleanup {
-	rm -f $all $search $in
+	rm -f $join $search $in
 }
 
-#trap cleanup EXIT
+trap cleanup EXIT
 cleanup
 
 if [ $# -lt 1 ] ; then
@@ -21,48 +25,61 @@ fi
 
 #
 # normalize to lower case all input file names
+# while building an enumeration of all distinct directories
 #
-
 for infn in $* ; do
 	dirn=$(dirname $infn)
 	df=
-	for dl in ${dirs[@]} ; do
+	for dl in $dirs ; do
 		if [ $dl == $dirn ] ; then
 			df=$dl
 			break;
 		fi
 	done
 	if [ -z $df ] ; then
-		dirs+=( $dirn )
+		dirs="$dirs $dirn"
 	fi
 	echo -n $dirn/ >> $in
 	basename $infn | tr '[A-Z]' '[a-z]' >> $in
 done
-
 sort -u $in > $search
-#echo search: 
-#cat $search
 
 here=$(pwd)
 
+#
+# if our cached join list matches our directory list, use it
+#
+if [ -f $cache ] ; then
+	cachedirs="$(head -1 $cache)"
+	if [ "$dirs" = "$cachedirs" ] ; then
+		tail -n +2 $cache > $join
+	else
+		rm -f $cache
+	fi
+fi
+
 #
 # build join list of file names and lower case forms
 #
-rm -f $in
-for dn in ${dirs[@]} ; do
-	cd $here
-	cd $dn
-	for i in * ; do
-		# skip any file names containing a space
-		if echo "$i" | grep -sq " " ; then
-			continue
-		fi
-		echo $dn/$(echo "$i" | tr '[A-Z]' '[a-z]')",$dn/$i" >> $in
+if [ ! -f $join ] ; then
+	rm -f $in
+	for dn in ${dirs[@]} ; do
+		cd $here
+		cd $dn
+		for i in * ; do
+			# skip any file names containing a space
+			if echo "$i" | grep -sq " " ; then
+				continue
+			fi
+			echo $dn/$(echo "$i" | tr '[A-Z]' '[a-z]')",$dn/$i" >> $in
+		done
 	done
-done
-sort -t, -k 1,1 $in > $all
+	sort -t, -k 1,1 $in > $join
+	echo "$dirs" > $cache
+	cat $join >> $cache
+fi
 
-join -t, -o 1.2 $all $search | sort -u > $in
+join -t, -o 1.2 $join $search | sort -u > $in
 if [ $(wc -l < $in) -gt 0 ] ; then
 	cat $in
 	exit 0