Denton Liu <liu.denton@xxxxxxxxx> writes:
> The code to test that objects were not missing from the packfile was
> duplicated many times. Extract the duplicated code into
> test_no_missing_in_packs() and use that instead.
>
> Refactor the resulting extraction so that if any git commands fail,
> their return codes are not silently lost.
>
> We were using sed to filter lines. Although not incorrect, this is
> exactly what grep is built for. Replace this invocation of sed with grep
> so that we use the correct tool for the job.
Well,
$ sed -n -e 's/required match/desired part of the line/p'
is much much more approirate than
$ grep -e "requred match" |
extract desired part of the line
"grep" is better only if the original were
$ sed -n -e '/required match/p'
but everybody would write it with grep to begin with ;-)
So, I dunno about this part of the conversion.
> Instead of verifying each file of `alt_objects/pack/*.idx` individually
> in a for-loop, batch them together into one verification step.
Do you mean this one?
git verify-pack -v alt_objects/pack/*.idx
where we may pass 1 or more .idx file to the command? At first my
reading was interrupted by a "Huh?", but that does look good. We'd
need to be a bit careful to make sure that we have at least 1 .idx
file, as the shell will happily feed a file whose name is "*.idx",
which verify-pack would be unhappy about.
> The original testing construct was O(n^2): it used a grep in a loop to
> test whether any objects were missing in the packfile. Rewrite this to
> sort the files then use `comm -23` so that finding missing lines from
> the original file is done more efficiently.
OK. If we an show measurable speedups, it would be great, but the
loop structure does look O(n^2) and unnecessary costly.
> +test_no_missing_in_packs () {
> + myidx=$(ls -1 .git/objects/pack/*.idx) &&
> + test_path_is_file "$myidx" &&
If there are 2 or more .idx files, or if there is none, $myidx would
hopefully be a concatenation of these filenames or a string that
ends with asterisk-dot-idx and would fail path_is_file. Sounds OK.
Ah, I do not have to review this part---these are repeated patterns
in the original.
> + git verify-pack -v alt_objects/pack/*.idx >orig.raw &&
> + grep "^[0-9a-f]\{40\}" orig.raw | cut -d" " -f1 | sort >orig &&
If output from 'grep' can be used as-is, it is worth doing, but if
you have to pipe it to cut, the original that used sed to filter and
edit the line would probably be a better way to write it.
> + git verify-pack -v $myidx >dest.raw &&
This part does not quote $myidx" (inherited from the original); it
probably is OK, as any potentially problematic value in $myidx would
have been caught as an error much earlier in this test.
