Re: [PATCH] FIFO header order support in HTTP::Headers

On Sep 5, 2008, at 7:23 PM, Gisle Aas wrote:
> True; and in this case we need to define what happens when fields are
> modified with 'push', 'set' or 'init' and 'remove' as that's the API
> that modify stuff.  Let me suggest the following definition of the
> behaviour:
>
> - 'push' always append the field at the end of all headers.  multiple
> occurrences of a field name do not have to be consecutive.
>
> - 'init' either does nothing or it works like 'push'.
>
> - 'remove' will always remove all concurrences of a field.
>
> - 'set' will work like 'push' if no other occurrence of the field  
> exists.
>
> - 'set' will update the first occurrence if the field exists (and
> remove all other occurrences).  if multiple field values is provided
> with 'set' they are basically all injected at the location of the
> first existing value.


On Sep 6, 2008 at 2:57 AM, Gisle Aas wrong:
> I think it makes sense to be able to enable them separately.
> Suggested interface:
>
>  $h->scan(\&cb, original_order => 1, original_case => 1);
>  $h->as_string(eol => "\n", original_order => 1, original_case => 1);'

The attached patch uses the interface above and works towards the  
behavior outlined in the first message.  Due to the headers being  
stored as a hash, pushing does not currently preserve previous values,  
second and subsequent pushes of the same header will overwrite the  
previous value.  Supporting this would require a change in how the  
headers are stored within the module.  Your thoughts?  The most  
obvious solution to me would be storing headers and their values as a  
hashref in an arrayref

Server: Fool/1.0
content-encoding: gzip
Content-Type: text/plain; charset="UTF-8"
Content-Encoding: base64
Date: Fri Sep  5 10:24:37 CEST 2008

Would be stored as (assuming push_header):

$self->{_headers} = [
	{ server => 'Fool/1.0' },
	{ content-encoding => 'gzip'},
	{ content-type => 'text/plain; charset="UTF-8"},
	{ content-encoding => 'base64' },
	{ date => 'Fri Sep  5 10:24:37 CEST 2008' }
];

This would negate the need for $self->{_original_order}.  $self- 
 >{_header} (or some such) could be a hashref with header fields as  
the keys and the header's index(s) in _headers as their value to speed  
and simplify direct access to an individual header's value.

--
Michael Greb
Linode.com
609-593-7103 ext 1205

From 2fd608a131e40375719bd79f6b427890a5db7529 Mon Sep 17 00:00:00 2001
From: Michael Greb <[email protected]>
Date: Sun, 7 Sep 2008 07:33:59 -0400
Subject: [PATCH] preservation of original header order and case

---
 lib/HTTP/Headers.pm |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/lib/HTTP/Headers.pm b/lib/HTTP/Headers.pm
index 5eb5329..c7d37dd 100644
--- a/lib/HTTP/Headers.pm
+++ b/lib/HTTP/Headers.pm
@@ -82,7 +82,7 @@ sub header
     my %seen;
     while (@_) {
 	my $field = shift;
-        my $op = @_ ? ($seen{lc($field)}++ ? 'PUSH' : 'SET') : 'GET';
+        my $op = @_ ? 'SET': 'GET';
 	@old = $self->_header($field, shift, $op);
     }
     return @old if wantarray;
@@ -117,9 +117,12 @@ sub remove_header
     my $field;
     my @values;
     foreach $field (@fields) {
-	$field =~ tr/_/-/ if $field !~ /^:/ && $TRANSLATE_UNDERSCORE;
-	my $v = delete $self->{lc $field};
-	push(@values, ref($v) eq 'ARRAY' ? @$v : $v) if defined $v;
+        $field =~ tr/_/-/ if $field !~ /^:/ && $TRANSLATE_UNDERSCORE;
+        $field = lc $field if $field !~ /^:/;
+        my $v = delete $self->{$field};
+        delete $self->{_original_case}{$field};
+        @{$self->{_original_order}} = grep !/^\Q$field\E$/, @{$self->{_original_order}};
+        push(@values, ref($v) eq 'ARRAY' ? @$v : $v) if defined $v;
     }
     return @values;
 }
@@ -167,7 +170,7 @@ sub _header
     $op ||= defined($val) ? 'SET' : 'GET';
     unless ($op eq 'GET' || ($op eq 'INIT' && @old)) {
         if (defined($val)) {
-            my @new = ($op eq 'PUSH') ? @old : ();
+            my @new = ($op eq 'SET') ? @old : ();
             if (ref($val) ne 'ARRAY') {
                 push(@new, $val);
             }
@@ -176,12 +179,12 @@ sub _header
             }
             $self->{$field} = @new > 1 ? \@new : $new[0];
             push @{$self->{_original_order}}, $field
-                if ($op eq 'PUSH' || !@old);
+                unless ($op eq 'SET' && @old);
         }
         elsif ($op ne 'PUSH') {
             delete $self->{$field};
             @{$self->{_original_order}} =
-                grep !/\Q$field\E/, @{$self->{_original_order}};
+                grep !/^\Q$field\E$/, @{$self->{_original_order}};
         }
     }
     @old;
-- 
1.5.5.3