Net::HTTP does not allow buffer size to be overridden in subclass [rt.cpan.org #25069]

Migrated from rt.cpan.org#25069 (status was 'open')

Requestors:

• dpisoni@cpan.org

From dpisoni@cpan.org on 2007-02-21 22:00:19:

In Net::HTTP, read_response_headers() uses the function my_readline() to do it's dirty-work.  
Under the hood, my_readline() calls sysread() with a HARD-CODED size of 1024.  Ideally, this 
should be an option, or otherwise parameterized.  Alternately, it would make sense to 
replace my_readline() in a subclass, but this is impossible since it is called as a function.  One 
would need to replace read_response_headers() entirely in a subclass if one wanted to 
change the behavior here (to capture a larger buffer in the first read, cutting down on 
latency.) Alternately, one could redefine the my_readline() function.  The last two options are 
terrible designs, since they involve cloning the existing code and replacing only a small bit, 
and may result in future incompatibilities.

	    my $n = $self->sysread($_, 1024, length);

I suggest you expose or otherwise parameterize this currently hard-coded value.

Here is my current (nasty) workaround in a subclass:
package MyNetHTTP;
use base 'Net::HTTP';
sub my_sysread {
    my $self = shift;
    $_[1] = $READ_BUFFER_LENGTH;
    $self->SUPER::sysread(@_);
}

sub read_response_headers {
    my $self = shift;
    local *sysread = *my_sysread;
    $self->SUPER::read_response_headers( @_ );
}

From ether@cpan.org on 2017-01-25 21:40:44:

migrated queues: libwww-perl -> Net-HTTP

Start by tracing read_response_headers() through my_readline() and the sysread() call described in the issue, including the hard-coded 1024-byte size. The work is done when the buffer size can be configured or the read helper can be overridden cleanly by a subclass without duplicating read_response_headers().