From: Luke Lu <git@vicaya.com>
Date: Wed, 17 Oct 2007 04:19:08 GMT
Subject: Re: [PATCH] gitweb: speed up project listing on large work trees by limiting find depth
Message-ID: <6B74E96C-37ED-4D6A-8A98-C90B61EFA181@vicaya.com>
In-Reply-To: <20071017040028.GT13801@spearce.org>


On Oct 16, 2007, at 9:00 PM, Shawn O. Pearce wrote:

> Luke Lu <git@vicaya.com> wrote:
>> Resubmitting patch after passing gitweb regression tests.
> ...
>> @@ -1519,6 +1524,11 @@ sub git_get_projects_list {
>>  				return if (m!^[/.]$!);
>>  				# only directories can be git repositories
>>  				return unless (-d $_);
>> +				# don't traverse too deep (Find is super slow on os x)
>> +				if (($File::Find::name =~ tr!/!!) - $pfxdepth >  
>> $project_maxdepth) {
>> +					$File::Find::prune = 1;
>> +					return;
>> +				}
>
> Thanks.  I'm squashing this into your patch.  I'm not sure what
> the impact is of altering $File::Find::name in the middle of the
> find algorithm and I'm not sure we want to figure that out later.
> We found out the hard way today that altering a non-local'd $_
> in the function is what was causing the breakage.

This is generally a good advice. But tr!/!! doesn't alter the string  
at all (OK, replicates it), unless you use the /d option. tr/stuff//  
is an idiom to count stuff. Check perldoc perlop for details. I don't  
think it's necessary.

>
> diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
> index 48e21da..9f47c3f 100755
> --- a/gitweb/gitweb.perl
> +++ b/gitweb/gitweb.perl
> @@ -1525,7 +1525,8 @@ sub git_get_projects_list {
>  				# only directories can be git repositories
>  				return unless (-d $_);
>  				# don't traverse too deep (Find is super slow on os x)
> -				if (($File::Find::name =~ tr!/!!) - $pfxdepth >  
> $project_maxdepth) {
> +				local $_ = $File::Find::name;
> +				if (tr!/!! - $pfxdepth > $project_maxdepth) {
>  					$File::Find::prune = 1;
>  					return;
>  				}
> -- 
> Shawn.