From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jakub Narebski <jnareb@gmail.com>
Subject: Re: [PATCH 2/2] gitweb: Make git_get_refs_list do work of git_get_references
Date: Thu, 21 Sep 2006 00:40:52 +0200
Message-ID: <200609210040.52886.jnareb@gmail.com>
References: <200609191430.51252.jnareb@gmail.com> <200609191433.22878.jnareb@gmail.com> <7veju6h0et.fsf@assigned-by-dhcp.cox.net>
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To: Junio C Hamano <junkio@cox.net>
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Junio C Hamano wrote:
> Jakub Narebski wrote:
>> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0if (=
! $4) { # unpeeled, direct reference
>> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0push @refs, { hash =3D> $1, name =3D> $3 }; # without=
 type
>> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0} el=
sif ($3 eq $refs[-1]{'name'}) {
>> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0# most likely a tag is followed by its peeled
>> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0# (deref) one, and when that happens we know the
>> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0# previous one was of type 'tag'.
>> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0$refs[-1]{'type'} =3D "tag";
>> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0}
>>...
>> -=A0=A0=A0=A0=A0return \@reflist;
>> +=A0=A0=A0=A0=A0return (\@reflist, \%refs);
>=20
> You are maintaining reflist (an array of hashrefs each element
> of which describes name, type, hash and other parse_ref()
> information for the ref) and refs (a hash that maps from name to
> hash) separatly. =A0I wonder if this really has the performance
> advantage over just compute and return reflist from here and
> have the callers who need the mapping to derive it from the list
> (i.e.
>=20
> =A0=A0=A0=A0=A0=A0=A0=A0my ($reflist) =3D git_get_refs_list();
> =A0=A0=A0=A0=A0=A0=A0=A0my %refs =3D map { $_->{name} =3D> $_->{hash}=
 } @$reflist;
> ).

The %refs hash contain also map from peeled (dereferenced) object
to ref name. The information about derefs is not present in @reflist.
So the answer is that you can't derive %refs from @reflist.=20
--=20
Jakub Narebski
ShadeHawk on #git
Poland