From 0429831551b044dc8e4d6ba7c842e1ce4761ed69 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Sun, 5 Nov 2017 04:23:13 +0200
Subject: [PATCH 1/1] prepare_data now only processes files based on
 modification time

---
 tools/prepare_data |   36 +++++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/tools/prepare_data b/tools/prepare_data
index c1bf5f8..7106581 100755
--- a/tools/prepare_data
+++ b/tools/prepare_data
@@ -4,6 +4,7 @@ indir=datasrc
 descfile=$indir/datadesc
 outdir=data
 filter=$1
+force_update=false
 
 process()
 {
@@ -34,6 +35,14 @@ copy()
 	fi
 }
 
+for arg; do
+	case "$arg" in
+	-f)
+		force=true
+		;;
+	esac
+done
+
 if [ -z "$filter" ]; then
 	filter='.*'
 fi
@@ -47,14 +56,23 @@ while read line; do
         fname=$(basename $path)
         op=$(echo $line | awk -F : '{ print $2; }' | xargs)
 
-        if [ "$op" = nop ]; then
-            echo copying $fname
-            mkdir -p $outdir/$(dirname $path)
-            copy $indir/$path $outdir/$path
-        else
-            echo processing $fname
-            mkdir -p $outdir/$(dirname $path)
-            process $indir/$path $outdir/$path "$op"
-        fi
+		infile=$indir/$path
+		outfile=$outdir/$path
+
+		if $force_update; then
+			touch "$infile"
+		fi
+
+		if [ "$infile" -nt "$outfile" ]; then
+			if [ "$op" = nop ]; then
+				echo copying $fname
+				mkdir -p $outdir/$(dirname $path)
+				copy $indir/$path $outdir/$path
+			else
+				echo processing $fname
+				mkdir -p $outdir/$(dirname $path)
+				process $indir/$path $outdir/$path "$op"
+			fi
+		fi
     fi
 done <$descfile
-- 
1.7.10.4