Re: [PATCH v2 4/5] convert: generate large test files only once

["Torsten Bögershausen" <tboegi@web.de>]

On 07/27/2016 02:06 AM, larsxschneider@gmail.com wrote:
> From: Lars Schneider <larsxschneider@gmail.com>
>
> Generate a more interesting large test file with random characters in
> between and reuse this test file in multiple tests. Run tests formerly
> marked as EXPENSIVE every time but with a smaller test file.
>
> Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
> ---
>  t/t0021-conversion.sh | 35 +++++++++++++++++++++++++----------
>  1 file changed, 25 insertions(+), 10 deletions(-)
>
> diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
> index 7b45136..b9911a4 100755
> --- a/t/t0021-conversion.sh
> +++ b/t/t0021-conversion.sh
> @@ -4,6 +4,13 @@ test_description='blob conversion via gitattributes'
>
>  . ./test-lib.sh
>
> +if test_have_prereq EXPENSIVE
> +then
> +	T0021_LARGE_FILE_SIZE=2048
> +else
> +	T0021_LARGE_FILE_SIZE=30
> +fi
> +
>  cat <<EOF >rot13.sh
>  #!$SHELL_PATH
>  tr \
> @@ -31,7 +38,15 @@ test_expect_success setup '
>  	cat test >test.i &&
>  	git add test test.t test.i &&
>  	rm -f test test.t test.i &&
> -	git checkout -- test test.t test.i
> +	git checkout -- test test.t test.i &&
> +
> +	mkdir -p generated-test-data &&
> +	for i in $(test_seq 1 $T0021_LARGE_FILE_SIZE)
> +	do
> +		# Generate 1MB of empty data and 100 bytes of random characters
> +		printf "%1048576d" 1
> +		printf "$(LC_ALL=C tr -dc "A-Za-z0-9" </dev/urandom | dd bs=$((RANDOM>>8)) count=1 2>/dev/null)"
I'm not sure how portable /dev/urandom is.
The other thing, that "really random" numbers are an overkill, and
it may be easier to use pre-defined numbers,

The rest of 1..4 looks good, I will look at 5/5 later.

> +	done >generated-test-data/large.file
>  '
>
>  script='s/^\$Id: \([0-9a-f]*\) \$/\1/p'
> @@ -199,9 +214,9 @@ test_expect_success 'required filter clean failure' '
>  test_expect_success 'filtering large input to small output should use little memory' '
>  	test_config filter.devnull.clean "cat >/dev/null" &&
>  	test_config filter.devnull.required true &&
> -	for i in $(test_seq 1 30); do printf "%1048576d" 1; done >30MB &&
> -	echo "30MB filter=devnull" >.gitattributes &&
> -	GIT_MMAP_LIMIT=1m GIT_ALLOC_LIMIT=1m git add 30MB
> +	cp generated-test-data/large.file large.file &&
> +	echo "large.file filter=devnull" >.gitattributes &&
> +	GIT_MMAP_LIMIT=1m GIT_ALLOC_LIMIT=1m git add large.file
>  '
>
>  test_expect_success 'filter that does not read is fine' '
> @@ -214,15 +229,15 @@ test_expect_success 'filter that does not read is fine' '
>  	test_cmp expect actual
>  '
>
> -test_expect_success EXPENSIVE 'filter large file' '
> +test_expect_success 'filter large file' '
>  	test_config filter.largefile.smudge cat &&
>  	test_config filter.largefile.clean cat &&
> -	for i in $(test_seq 1 2048); do printf "%1048576d" 1; done >2GB &&
> -	echo "2GB filter=largefile" >.gitattributes &&
> -	git add 2GB 2>err &&
> +	echo "large.file filter=largefile" >.gitattributes &&
> +	cp generated-test-data/large.file large.file &&
> +	git add large.file 2>err &&
>  	test_must_be_empty err &&
> -	rm -f 2GB &&
> -	git checkout -- 2GB 2>err &&
> +	rm -f large.file &&
> +	git checkout -- large.file 2>err &&
>  	test_must_be_empty err
>  '
>
>