Re: [PATCH 2/5] git-svn: memoize conversion of SVN merge ticket info to git commit ranges

> Each time the svn mergeinfo ticket changes, we look it up in the rev_map;
> when there are a lot of merged branches, this will result in many repeated
> lookups of the same information for subsequent commits.  Arrange the slow
> part of the function so that it may be memoized, and memoize it.  The more
> expensive revision walking operation can be memoized separately.
> 
> Signed-off-by: Sam Vilain <sam@vilain.net>
> ---
>  git-svn.perl |   91 ++++++++++++++++++++++++++++++++++-----------------------
>  1 files changed, 54 insertions(+), 37 deletions(-)
> 
> diff --git a/git-svn.perl b/git-svn.perl
> index a4b052c..3b17a83 100755
> --- a/git-svn.perl
> +++ b/git-svn.perl
> @@ -1634,6 +1634,7 @@ use Carp qw/croak/;
>  use File::Path qw/mkpath/;
>  use File::Copy qw/copy/;
>  use IPC::Open3;
> +use Memoize;  # core since 5.8.0, Jul 2002
>  
>  my ($_gc_nr, $_gc_period);
>  
> @@ -2967,6 +2968,55 @@ sub find_extra_svk_parents {
>  	}
>  }
>  
> +sub lookup_svn_merge {
> +	my $uuid = shift;
> +	my $url = shift;
> +	my $merge = shift;
> +
> +	my ($source, $revs) = split ":", $merge;
> +	my $path = $source;
> +	$path =~ s{^/}{};
> +	my $gs = Git::SVN->find_by_url($url.$source, $url, $path);
> +	if ( !$gs ) {
> +		warn "Couldn't find revmap for $url$source\n";
> +		next;
> +	}