Re: Drastic jump in the time required for the test suite

Junio C Hamano <gitster@pobox.com> writes:

The language (/bin/sh) is probably not the biggest issue. The way we use it may be.

I don't have benchmark to tell what slows down the testsuite, but for example we often write

	cat >expected <<EOF &&
	content
	EOF
	git foo >actual &&
	test_cmp expected actual

We create 2 files, fork one 'cat' and one 'diff'. Now, suppose we can write instead

	test_check_output git foo <<EOF
	content
	EOF

where test_check_output would be a compiled program running "git foo" with popen(), reading the expected output on stdin, and comparing both (and possibly creating files and forking 'diff', but only on the error path). That would reduce the overhead of test a lot: on fork+exec to create the "test_check_output" process + plain string comparison.

Obviously, I don't expect this change to drastically reduce the time (Peff's numbers seem to suggest that there's not so much to gain), but maybe getting a few C helpers and "optimized" idioms in our testsuite could lead to measurable improvements.