Re: multi-install PostgresNode fails with older postgres versions

Alvaro Herrera <alvherre@alvh.no-ip.org>

From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Andrew Dunstan <andrew@dunslane.net>
Cc: Michael Paquier <michael@paquier.xyz>, Mark Dilger <mark.dilger@enterprisedb.com>, Jehan-Guillaume de Rorthais <jgdr@dalibo.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2021-04-22T15:09:54Z
Lists: pgsql-hackers
On 2021-Apr-21, Andrew Dunstan wrote:

> +=head1 DESCRIPTION
> +
> +PostgresVersion encapsulated Postgres version numbers, providing parsing
> +of common version formats and comparison operations.

Small typo here: should be "encapsulates"

> +	# Accept standard formats, in case caller has handed us the output of a
> +	# postgres command line tool
> +	$arg = $1
> +		if ($arg =~ m/\(?PostgreSQL\)? (\d+(?:\.\d+)*(?:devel)?)/);
> +
> +	# Split into an array
> +	my @result = split(/\./, $arg);
> +
> +	# Treat development versions as having a minor/micro version one less than
> +	# the first released version of that branch.
> +	if ($result[$#result] =~ m/^(\d+)devel$/)
> +	{
> +		pop(@result);
> +		push(@result, $1, -1);
> +	}

It's a bit weird to parse the "devel" bit twice.  Would it work to leave
(?:devel)? out of the capturing parens that becomes $1 in the first
regex and make it capturing itself, so you get "devel" in $2, and decide
based on its presence/absence?  Then you don't have to pop and push a -1.

> +	my $res = [ @result ];

Hmm, isn't this just \@result?  So you could do
	return bless \@result, $class;

-- 
Álvaro Herrera                            39°49'30"S 73°17'W



Commits

  1. Teach PostgresVersion all the ways to mark non-release code

  2. Make PostgresNode version aware

  3. Avoid unfortunate IPC::Run path caching in PostgresNode

  4. Change pg_ctl to detect server-ready by watching status in postmaster.pid.