Re: multithreaded zstd backup compression for client and server

Robert Haas <robertmhaas(at)gmail(dot)com> writes:

> On Mon, Mar 28, 2022 at 12:52 PM Dagfinn Ilmari Mannsåker
> <ilmari(at)ilmari(dot)org> wrote:
>> > True, but that also means it shows up in the actual failure message,
>> > which seems too verbose. By just using 'print', it ends up in the log
>> > file if it's needed, but not anywhere else. Maybe there's a better way
>> > to do this, but I don't think using note() is what I want.
>>
>> That is the difference between note() and diag(): note() prints to
>> stdout so is not visible under a non-verbose prove run, while diag()
>> prints to stderr so it's always visible.
>
> OK, but print doesn't do either of those things. The output only shows
> up in the log file, even with --verbose. Here's an example of what the
> log file looks like:
>
> # Running: pg_verifybackup -n -m
> /Users/rhaas/pgsql/src/bin/pg_verifybackup/tmp_check/t_008_untar_primary_data/backup/server-backup/backup_manifest
> -e /Users/rhaas/pgsql/src/bin/pg_verifybackup/tmp_check/t_008_untar_primary_data/backup/extracted-backup
> backup successfully verified
> ok 6 - verify backup, compression gzip
>
> As you can see, there is a line here that does not begin with #. That
> line is the standard output of a command that was run by the test
> script.

Oh, that must be some non-standard output handling that our test setup
does. Plain `prove` shows everything on stdout and stderr in verbose
mode, and only stderr in non-vebose mode:

$ cat verbosity.t
use strict;
use warnings;

use Test::More;

pass "pass";

diag "diag";
note "note";
print "print\n";
system qw(echo system);

done_testing;

$ prove verbosity.t
verbosity.t .. 1/? # diag
verbosity.t .. ok
All tests successful.
Files=1, Tests=1, 0 wallclock secs ( 0.02 usr 0.00 sys + 0.04 cusr 0.01 csys = 0.07 CPU)
Result: PASS

$ prove -v verbosity.t
verbosity.t ..
ok 1 - pass
# diag
# note
print
system
1..1
ok
All tests successful.
Files=1, Tests=1, 0 wallclock secs ( 0.02 usr 0.00 sys + 0.06 cusr 0.00 csys = 0.08 CPU)
Result: PASS

- ilmari