Re: Drastic jump in the time required for the test suite
- From
Jeff King <peff@peff.net>
- Date
- Oct 20, 2016, 21:56 UTC
- Message-ID
- <20161020215647.5no7effvutwep2xt@sigill.intra.peff.net>
- In-Reply-To
- <20161020213803.7d7bymby7pouzij3@sigill.intra.peff.net>
On Thu, Oct 20, 2016 at 05:38:03PM -0400, Jeff King wrote:
Show 7 quoted lines
> I think that helper still ends up using "cat" and "diff" under the hood, > unless you write those bits in pure shell. But at that point, I suspect > we could "cat" and "test_cmp" in pure shell, something like: > [...] > Those are both completely untested. But maybe they are worth playing > around with for somebody on Windows to see if they make a dent in the > test runtime.
If you tried to run them, you probably noticed that the "untested" was really true. One of the functions was missing an "else", and the other forgot to add a "\n" to its printf.
The patch below gets closer, though there are still a handful of test failures. I didn't investigate deeply, but I think at least one is related to the "read/printf" version of cat not being binary-clean.
-Peff
---
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh index fdaeb3a96b..de37f3d 100644 --- a/t/test-lib-functions.sh +++ b/t/test-lib-functions.sh @@ -685,9 +685,48 @@ test_expect_code () { # - not all diff versions understand "-u" test_cmp() { + # optimize for common "they are the same" case + # without any subshells or subprograms + while true; do + if ! read -r line1 <&3 + then + if ! read -r line2 <&4 + then + # EOF on both; good + return 0 + else + # EOF only on file1; fail + break + fi + fi + if ! read -r line2 <&4 + then + # EOF only on file2; fail + break + fi + test "$line1" = "$line2" || break + done 3<"$1" 4<"$2" + + # if we get here, the optimized version found some + # difference. We can just "return 1", but let's run + # the real $GIT_TEST_CMP to provide pretty output. + # This should generally only happen on test failures, + # so performance isn't a big deal. $GIT_TEST_CMP "$@" } +cat () { + # optimize common here-doc usage + if test $# -eq 0 + then + while read -r line + do + printf '%s\n' "$line" + done + fi + command cat "$@" +} + # test_cmp_bin - helper to compare binary files test_cmp_bin() {