[ic] [interchange] Only apply GDBM filters if they are not already installed

[Stefan Hornburg (Racke)]

On 08/31/2012 04:04 AM, Mike Heins wrote:
> Quoting David Christensen (interchange-cvs at icdevgroup.org):
>> commit 0c31ea3287df97c8fedbf23ad71244e4ebe019c7
>> Author: David Christensen<david at endpoint.com>
>> Date:   Thu Aug 30 20:01:28 2012 -0500
>>
>>      Only apply GDBM filters if they are not already installed
>>
>>      In certain circumstances, using the same GDBM-based file in multiple catalogs with
>>      GDBM_ENABLE_UTF8=1 set was causing the GDBM filters to be installed multiple times on the same
>>      handle, which was resulting in encoding/decoding errors.
>>
>>      Vend::Table::GDBM will now only install the filters if they do not exist on this handle, which
>>      should preserve existing behavior plus account for these corner-cases.
>>
>>   lib/Vend/Table/GDBM.pm |    8 ++++----
>>   1 files changed, 4 insertions(+), 4 deletions(-)
>> ---
>> diff --git a/lib/Vend/Table/GDBM.pm b/lib/Vend/Table/GDBM.pm
>> index fb82dbb..559f904 100644
>> --- a/lib/Vend/Table/GDBM.pm
>> +++ b/lib/Vend/Table/GDBM.pm
>> @@ -150,10 +150,10 @@ sub apply_utf8_filters {
>>   	my $out_filter = sub { $_ = encode('utf-8', $_) };
>>   	my $in_filter  = sub { $_ = decode('utf-8', $_) };
>>
>> -	$handle->filter_store_key($out_filter);
>> -	$handle->filter_store_value($out_filter);
>> -	$handle->filter_fetch_key($in_filter);
>> -	$handle->filter_fetch_value($in_filter);
>> +	$handle->filter_store_key($out_filter)   unless $handle->filter_store_key();
>> +	$handle->filter_store_value($out_filter) unless $handle->filter_store_value();
>> +	$handle->filter_fetch_key($in_filter)    unless $handle->filter_fetch_key();
>> +	$handle->filter_fetch_value($in_filter)  unless $handle->filter_fetch_value();
>>
>
> Couldn't we cut down object calls? It seems to me that you should be able
> to do:
>
> --- a/lib/Vend/Table/GDBM.pm	2012-08-30 22:02:19.152103476 -0400
> +++ a/lib/Vend/Table/GDBM.pm	2012-08-30 22:01:16.000000000 -0400
> @@ -146,6 +146,8 @@
>   sub apply_utf8_filters {
>   	my ($handle) = shift;
>
> +	return if $handle->filter_store_key();
> +
>   #::logDebug("applying UTF-8 filters to GDBM handle");
>
>   	my $out_filter = sub { $_ = encode('utf-8', $_) };
>
> Every little bit helps. That reduces object calls by three and subroutine
> creation overhead by two.
>

What about using DBM_Filter?

https://metacpan.org/module/DBM_Filter

That seems to have an easier interface and comes with Perl.

Regards
         Racke

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