tests: factor out fs-agnostic benchmark script

"canonical-benchmarks.bash TESTDIR"
can now be used on any filesystem.

benchmark.bash

@@ -1,42 +1,28 @@
-#!/bin/bash
+#!/bin/bash -eu
 
 # Run the set of "canonical" benchmarks that are shown on
 # https://nuetzlich.net/gocryptfs/comparison/
 
-set -eu
-
-TIME="/usr/bin/time -f %e"
+cd "$(dirname "$0")"
 
 # Setup
-cd /tmp
-wget -nv --show-progress -c https://www.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.gz
-DIR1=$(mktemp -d)
-DIR2=$(mktemp -d)
+CRYPT=$(mktemp -d /tmp/benchmark.bash.XXX)
+MNT=$CRYPT.mnt
+mkdir $MNT
 
+# Mount
 if [ $# -eq 1 ] && [ "$1" == "-encfs" ]; then
-	echo "Testing EncFS"
-	encfs --extpass="echo test" --standard $DIR1 $DIR2 > /dev/null
+	echo "Testing EncFS at $MNT"
+	encfs --extpass="echo test" --standard $CRYPT $MNT > /dev/null
 else
-	gocryptfs -q -init -extpass="echo test" -scryptn=10 $DIR1
-	gocryptfs -q -extpass="echo test" $DIR1 $DIR2
+	echo "Testing gocryptfs at $MNT"
+	gocryptfs -q -init -extpass="echo test" -scryptn=10 $CRYPT
+	gocryptfs -q -extpass="echo test" $CRYPT $MNT
 fi
-cd $DIR2
+
+# Cleanup trap
+trap "cd /; fusermount -u -z $MNT; rm -rf $CRYPT $MNT" EXIT
 
 # Benchmarks
-echo -n "WRITE: "
-dd if=/dev/zero of=zero bs=128K count=1000 2>&1 | tail -n 1
-rm zero
-sleep 1
-echo -n "UNTAR: "
-$TIME tar xzf ../linux-3.0.tar.gz
-sleep 1
-echo -n "LS:    "
-$TIME ls -lR linux-3.0 > /dev/null
-sleep 1
-echo -n "RM:    "
-$TIME rm -Rf linux-3.0
+./tests/canonical-benchmarks.bash $MNT
 
-# Cleanup
-cd ..
-fusermount -u $DIR2 -z
-rm -Rf $DIR1 $DIR2

tests/canonical-benchmarks.bash

@@ -0,0 +1,41 @@
+#!/bin/bash -eu
+#
+# Run the set of "canonical" benchmarks that are shown on
+# https://nuetzlich.net/gocryptfs/comparison/
+# against the directory passed as "$1".
+#
+# This is called by the top-level script "benchmark.bash".
+
+if [ $# -ne 1 ]; then
+	MYNAME=$(basename $0)
+	echo "usage: $MYNAME TESTDIR"
+	exit 1
+fi
+
+cd "$1"
+
+TGZ=/tmp/linux-3.0.tar.gz
+
+if [ "$(md5sum /tmp/linux-3.0.tar.gz | cut -f1 -d' ')" != \
+	"f7e6591d86a9dbe123dfd1a0be054e7f" ]; then
+	echo "Downloading linux-3.0.tar.gz"
+	wget -nv --show-progress -c -O $TGZ \
+		https://www.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.gz
+fi
+
+function etime {
+	LC_ALL=C /usr/bin/time -f %e 2>&1 $@ > /dev/null
+}
+
+echo -n "WRITE: "
+dd if=/dev/zero of=zero bs=128K count=1000 2>&1 | tail -n 1
+rm zero
+sleep 1
+echo -n "UNTAR: "
+etime tar xzf $TGZ
+sleep 1
+echo -n "LS:    "
+etime ls -lR linux-3.0
+sleep 1
+echo -n "RM:    "
+etime rm -Rf linux-3.0