X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FClass%2FAccessor%2FGrouped.pm;h=afe019bd62a15bb2f04c13edac472098cd61b093;hb=00e42e876950facc93918342bf6a4bfc1bc0a985;hp=a62d12e399aec53478b2ecca670b9aa60a28fa7d;hpb=46f1ef81bdf4519f8fff9952d35b5dbf73adfade;p=p5sagit%2FClass-Accessor-Grouped.git diff --git a/lib/Class/Accessor/Grouped.pm b/lib/Class/Accessor/Grouped.pm index a62d12e..afe019b 100644 --- a/lib/Class/Accessor/Grouped.pm +++ b/lib/Class/Accessor/Grouped.pm @@ -2,32 +2,119 @@ package Class::Accessor::Grouped; use strict; use warnings; use Carp (); -use Class::Inspector (); use Scalar::Util (); -use MRO::Compat; -use Sub::Name (); +use Module::Runtime (); -our $VERSION = '0.09002'; -$VERSION = eval $VERSION; +BEGIN { + # use M::R to work around the 5.8 require bugs + if ($] < 5.009_005) { + Module::Runtime::require_module('MRO::Compat'); + } + else { + require mro; + } +} -# Class::XSAccessor is segfaulting on win32, so be careful -# Win32 users can set $hasXS to try to use it anyway -our $hasXS; -sub _hasXS { +our $VERSION = '0.10007'; +$VERSION = eval $VERSION if $VERSION =~ /_/; # numify for warning-free dev releases + +# when changing minimum version don't forget to adjust Makefile.PL as well +our $__minimum_xsa_version; +BEGIN { $__minimum_xsa_version = '1.15' } + +our $USE_XS; +# the unless defined is here so that we can override the value +# before require/use, *regardless* of the state of $ENV{CAG_USE_XS} +$USE_XS = $ENV{CAG_USE_XS} + unless defined $USE_XS; + +BEGIN { + package # hide from PAUSE + __CAG_ENV__; + + die "Huh?! No minimum C::XSA version?!\n" + unless $__minimum_xsa_version; + + local $@; + require constant; + + # individual (one const at a time) imports so we are 5.6.2 compatible + # if we can - why not ;) + constant->import( NO_SUBNAME => eval { + Module::Runtime::require_module('Sub::Name') + } ? 0 : "$@" ); + + my $found_cxsa; + constant->import( NO_CXSA => ( !NO_SUBNAME() and eval { + Module::Runtime::require_module('Class::XSAccessor'); + $found_cxsa = Class::XSAccessor->VERSION; + Class::XSAccessor->VERSION($__minimum_xsa_version); + } ) ? 0 : "$@" ); + + if (NO_CXSA() and $found_cxsa and !$ENV{CAG_OLD_XS_NOWARN}) { + warn( + 'The installed version of Class::XSAccessor is too old ' + . "(v$found_cxsa < v$__minimum_xsa_version). Please upgrade " + . "to instantly quadruple the performance of 'simple' accessors. " + . 'Set $ENV{CAG_OLD_XS_NOWARN} if you wish to disable this ' + . "warning.\n" + ); + } - if (not defined $hasXS) { - $hasXS = 0; + constant->import( BROKEN_GOTO => ($] < '5.008009') ? 1 : 0 ); - if ($^O ne 'MSWin32') { - eval { - require Class::XSAccessor; - $hasXS = 1; - }; + constant->import( UNSTABLE_DOLLARAT => ($] < '5.013002') ? 1 : 0 ); + + constant->import( TRACK_UNDEFER_FAIL => ( + $INC{'Test/Builder.pm'} || $INC{'Test/Builder2.pm'} + and + $0 =~ m|^ x?t / .+ \.t $|x + ) ? 1 : 0 ); +} + +# Yes this method is undocumented +# Yes it should be a private coderef like all the rest at the end of this file +# No we can't do that (yet) because the DBIC-CDBI compat layer overrides it +# %$*@!?&!&#*$!!! +sub _mk_group_accessors { + my($self, $maker, $group, @fields) = @_; + my $class = length (ref ($self) ) ? ref ($self) : $self; + + no strict 'refs'; + no warnings 'redefine'; + + # So we don't have to do lots of lookups inside the loop. + $maker = $self->can($maker) unless ref $maker; + + for (@fields) { + + my ($name, $field) = (ref $_) ? (@$_) : ($_, $_); + + Carp::croak("Illegal accessor name '$name'") + unless $name =~ /\A[A-Z_a-z][0-9A-Z_a-z]*\z/; + + Carp::carp("Having a data accessor named '$name' in '$class' is unwise.") + if $name =~ /\A(?: DESTROY | AUTOLOAD | CLONE )\z/x; + + my $alias = "_${name}_accessor"; + + for ($name, $alias) { + + # the maker may elect to not return anything, meaning it already + # installed the coderef for us (e.g. lack of Sub::Name) + my $cref = $self->$maker($group, $field, $_) + or next; + + my $fq_meth = "${class}::$_"; + + *$fq_meth = Sub::Name::subname($fq_meth, $cref); + #unless defined &{$class."\:\:$field"} } } +}; - return $hasXS; -} +# $gen_accessor coderef is setup at the end for clarity +my $gen_accessor; =head1 NAME @@ -35,6 +122,14 @@ Class::Accessor::Grouped - Lets you build groups of accessors =head1 SYNOPSIS + use base 'Class::Accessor::Grouped'; + + # make basic accessors for objects + __PACKAGE__->mk_group_accessors(simple => qw(id name email)); + + # make accessor that works for objects and classes + __PACKAGE__->mk_group_accessors(inherited => 'awesome_level'); + =head1 DESCRIPTION This class lets you build groups of accessors that will call different @@ -44,6 +139,8 @@ getters and setters. =head2 mk_group_accessors + __PACKAGE__->mk_group_accessors(simple => 'hair_length', [ hair_color => 'hc' ]); + =over 4 =item Arguments: $group, @fieldspec @@ -74,57 +171,10 @@ sub mk_group_accessors { return; } - -{ - no strict 'refs'; - no warnings 'redefine'; - - sub _mk_group_accessors { - my($self, $maker, $group, @fields) = @_; - my $class = Scalar::Util::blessed $self || $self; - - # So we don't have to do lots of lookups inside the loop. - $maker = $self->can($maker) unless ref $maker; - - my $hasXS = _hasXS(); - - foreach my $field (@fields) { - if( $field eq 'DESTROY' ) { - Carp::carp("Having a data accessor named DESTROY in ". - "'$class' is unwise."); - } - - my $name = $field; - - ($name, $field) = @$field if ref $field; - - my $alias = "_${name}_accessor"; - my $full_name = join('::', $class, $name); - my $full_alias = join('::', $class, $alias); - - if ( $hasXS && $group eq 'simple' ) { - require Class::XSAccessor; - Class::XSAccessor::newxs_accessor("${class}::${name}", $field, 0); - Class::XSAccessor::newxs_accessor("${class}::${alias}", $field, 0); - - # XXX: is the alias accessor really necessary? - } - else { - my $accessor = $self->$maker($group, $field); - my $alias_accessor = $self->$maker($group, $field); - - *$full_name = Sub::Name::subname($full_name, $accessor); - #unless defined &{$class."\:\:$field"} - - *$full_alias = Sub::Name::subname($full_alias, $alias_accessor); - #unless defined &{$class."\:\:$alias"} - } - } - } -} - =head2 mk_group_ro_accessors + __PACKAGE__->mk_group_ro_accessors(simple => 'birthdate', [ social_security_number => 'ssn' ]); + =over 4 =item Arguments: $group, @fieldspec @@ -140,13 +190,16 @@ rather than setting the value. =cut sub mk_group_ro_accessors { - my($self, $group, @fields) = @_; + my($self, $group, @fields) = @_; - $self->_mk_group_accessors('make_group_ro_accessor', $group, @fields); + $self->_mk_group_accessors('make_group_ro_accessor', $group, @fields); + return; } =head2 mk_group_wo_accessors + __PACKAGE__->mk_group_wo_accessors(simple => 'lie', [ subject => 'subj' ]); + =over 4 =item Arguments: $group, @fieldspec @@ -162,105 +215,10 @@ value rather than getting the value. =cut sub mk_group_wo_accessors { - my($self, $group, @fields) = @_; - - $self->_mk_group_accessors('make_group_wo_accessor', $group, @fields); -} - -=head2 make_group_accessor - -=over 4 + my($self, $group, @fields) = @_; -=item Arguments: $group, $field - -Returns: $sub (\CODE) - -=back - -Returns a single accessor in a given group; called by mk_group_accessors -for each entry in @fieldspec. - -=cut - -sub make_group_accessor { - my ($class, $group, $field) = @_; - - my $set = "set_$group"; - my $get = "get_$group"; - - # eval for faster fastiness - return eval "sub { - if(\@_ > 1) { - return shift->$set('$field', \@_); - } - else { - return shift->$get('$field'); - } - };" -} - -=head2 make_group_ro_accessor - -=over 4 - -=item Arguments: $group, $field - -Returns: $sub (\CODE) - -=back - -Returns a single read-only accessor in a given group; called by -mk_group_ro_accessors for each entry in @fieldspec. - -=cut - -sub make_group_ro_accessor { - my($class, $group, $field) = @_; - - my $get = "get_$group"; - - return eval "sub { - if(\@_ > 1) { - my \$caller = caller; - Carp::croak(\"'\$caller' cannot alter the value of '$field' on \". - \"objects of class '$class'\"); - } - else { - return shift->$get('$field'); - } - };" -} - -=head2 make_group_wo_accessor - -=over 4 - -=item Arguments: $group, $field - -Returns: $sub (\CODE) - -=back - -Returns a single write-only accessor in a given group; called by -mk_group_wo_accessors for each entry in @fieldspec. - -=cut - -sub make_group_wo_accessor { - my($class, $group, $field) = @_; - - my $set = "set_$group"; - - return eval "sub { - unless (\@_ > 1) { - my \$caller = caller; - Carp::croak(\"'\$caller' cannot access the value of '$field' on \". - \"objects of class '$class'\"); - } - else { - return shift->$set('$field', \@_); - } - };" + $self->_mk_group_accessors('make_group_wo_accessor', $group, @fields); + return; } =head2 get_simple @@ -279,7 +237,7 @@ name passed as an argument. =cut sub get_simple { - return $_[0]->{$_[1]}; + $_[0]->{$_[1]}; } =head2 set_simple @@ -298,7 +256,7 @@ for the field name passed as an argument. =cut sub set_simple { - return $_[0]->{$_[1]} = $_[2]; + $_[0]->{$_[1]} = $_[2]; } @@ -321,37 +279,30 @@ instances. =cut sub get_inherited { - my $class; - - if (Scalar::Util::blessed $_[0]) { - my $reftype = Scalar::Util::reftype $_[0]; - $class = ref $_[0]; - - if ($reftype eq 'HASH' && exists $_[0]->{$_[1]}) { - return $_[0]->{$_[1]}; - } elsif ($reftype ne 'HASH') { - Carp::croak('Cannot get inherited value on an object instance that is not hash-based'); - }; - } else { - $class = $_[0]; - }; + if ( length (ref ($_[0]) ) ) { + if (Scalar::Util::reftype $_[0] eq 'HASH') { + return $_[0]->{$_[1]} if exists $_[0]->{$_[1]}; + # everything in @_ is aliased, an assignment won't work + splice @_, 0, 1, ref($_[0]); + } + else { + Carp::croak('Cannot get inherited value on an object instance that is not hash-based'); + } + } - no strict 'refs'; - no warnings qw/uninitialized/; - return ${$class.'::__cag_'.$_[1]} if defined(${$class.'::__cag_'.$_[1]}); + # if we got this far there is nothing in the instance + # OR this is a class call + # in any case $_[0] contains the class name (see splice above) + no strict 'refs'; + no warnings 'uninitialized'; - # we need to be smarter about recalculation, as @ISA (thus supers) can very well change in-flight - my $pkg_gen = mro::get_pkg_gen ($class); - if ( ${$class.'::__cag_pkg_gen'} != $pkg_gen ) { - @{$class.'::__cag_supers'} = $_[0]->get_super_paths; - ${$class.'::__cag_pkg_gen'} = $pkg_gen; - }; + my $cag_slot = '::__cag_'. $_[1]; + return ${$_[0].$cag_slot} if defined(${$_[0].$cag_slot}); - foreach (@{$class.'::__cag_supers'}) { - return ${$_.'::__cag_'.$_[1]} if defined(${$_.'::__cag_'.$_[1]}); - }; + do { return ${$_.$cag_slot} if defined(${$_.$cag_slot}) } + for $_[0]->get_super_paths; - return undef; + return undef; } =head2 set_inherited @@ -375,17 +326,16 @@ hash-based object. =cut sub set_inherited { - if (Scalar::Util::blessed $_[0]) { - if (Scalar::Util::reftype $_[0] eq 'HASH') { - return $_[0]->{$_[1]} = $_[2]; - } else { - Carp::croak('Cannot set inherited value on an object instance that is not hash-based'); - }; + if (length (ref ($_[0]) ) ) { + if (Scalar::Util::reftype $_[0] eq 'HASH') { + return $_[0]->{$_[1]} = $_[2]; } else { - no strict 'refs'; - - return ${$_[0].'::__cag_'.$_[1]} = $_[2]; + Carp::croak('Cannot set inherited value on an object instance that is not hash-based'); }; + } + + no strict 'refs'; + ${$_[0].'::__cag_'.$_[1]} = $_[2]; } =head2 get_component_class @@ -400,17 +350,17 @@ Returns: $value Gets the value of the specified component class. - __PACKAGE__->mk_group_accessors('component_class' => 'result_class'); + __PACKAGE__->mk_group_accessors('component_class' => 'result_class'); - $self->result_class->method(); + $self->result_class->method(); - ## same as - $self->get_component_class('result_class')->method(); + ## same as + $self->get_component_class('result_class')->method(); =cut sub get_component_class { - return $_[0]->get_inherited($_[1]); + $_[0]->get_inherited($_[1]); }; =head2 set_component_class @@ -426,63 +376,466 @@ Returns: $new_value Inherited accessor that automatically loads the specified class before setting it. This method will die if the specified class could not be loaded. - __PACKAGE__->mk_group_accessors('component_class' => 'result_class'); - __PACKAGE__->result_class('MyClass'); + __PACKAGE__->mk_group_accessors('component_class' => 'result_class'); + __PACKAGE__->result_class('MyClass'); - $self->result_class->method(); + $self->result_class->method(); =cut sub set_component_class { - if ($_[2]) { - local $^W = 0; - if (Class::Inspector->installed($_[2]) && !Class::Inspector->loaded($_[2])) { - eval "use $_[2]"; + if (defined $_[2] and length $_[2]) { + # disable warnings, and prevent $_ being eaten away by a behind-the-scenes + # module loading + local ($^W, $_); + + if (__CAG_ENV__::UNSTABLE_DOLLARAT) { + my $err; + { + local $@; + eval { Module::Runtime::use_package_optimistically($_[2]) } + or $err = $@; + } + Carp::croak("Could not load $_[1] '$_[2]': $err") if defined $err; - Carp::croak("Could not load $_[1] '$_[2]': ", $@) if $@; - }; - }; + } + else { + eval { Module::Runtime::use_package_optimistically($_[2]) } + or Carp::croak("Could not load $_[1] '$_[2]': $@"); + } + }; - return $_[0]->set_inherited($_[1], $_[2]); + $_[0]->set_inherited($_[1], $_[2]); }; +=head1 INTERNAL METHODS + +These methods are documented for clarity, but are never meant to be called +directly, and are not really meant for overriding either. + =head2 get_super_paths -Returns a list of 'parent' or 'super' class names that the current class inherited from. +Returns a list of 'parent' or 'super' class names that the current class +inherited from. This is what drives the traversal done by L. =cut sub get_super_paths { - my $class = Scalar::Util::blessed $_[0] || $_[0]; - - return @{mro::get_linear_isa($class)}; + # get_linear_isa returns the class itself as the 1st element + # use @_ as a pre-allocated scratch array + (undef, @_) = @{mro::get_linear_isa( length( ref($_[0]) ) ? ref($_[0]) : $_[0] )}; + @_; }; -1; +=head2 make_group_accessor + + __PACKAGE__->make_group_accessor('simple', 'hair_length', 'hair_length'); + __PACKAGE__->make_group_accessor('simple', 'hc', 'hair_color'); + +=over 4 + +=item Arguments: $group, $field, $accessor -=head1 Performance +Returns: \&accessor_coderef ? + +=back + +Called by mk_group_accessors for each entry in @fieldspec. Either returns +a coderef which will be installed at C<&__PACKAGE__::$accessor>, or returns +C if it elects to install the coderef on its own. + +=cut + +sub make_group_accessor { $gen_accessor->('rw', @_) } + +=head2 make_group_ro_accessor + + __PACKAGE__->make_group_ro_accessor('simple', 'birthdate', 'birthdate'); + __PACKAGE__->make_group_ro_accessor('simple', 'ssn', 'social_security_number'); + +=over 4 -You can speed up accessors of type 'simple' by installing L. -Note however that the use of this module is disabled by default on Win32 -systems, as it causes yet untracked segfaults. If you are a Win32 user, and -want to try this module with L, set -C<$Class::Accessor::Grouped::hasXS> to a true value B registering -your accessors (e.g. in a C block) +=item Arguments: $group, $field, $accessor + +Returns: \&accessor_coderef ? + +=back + +Called by mk_group_ro_accessors for each entry in @fieldspec. Either returns +a coderef which will be installed at C<&__PACKAGE__::$accessor>, or returns +C if it elects to install the coderef on its own. + +=cut + +sub make_group_ro_accessor { $gen_accessor->('ro', @_) } + +=head2 make_group_wo_accessor + + __PACKAGE__->make_group_wo_accessor('simple', 'lie', 'lie'); + __PACKAGE__->make_group_wo_accessor('simple', 'subj', 'subject'); + +=over 4 + +=item Arguments: $group, $field, $accessor + +Returns: \&accessor_coderef ? + +=back + +Called by mk_group_wo_accessors for each entry in @fieldspec. Either returns +a coderef which will be installed at C<&__PACKAGE__::$accessor>, or returns +C if it elects to install the coderef on its own. + +=cut + +sub make_group_wo_accessor { $gen_accessor->('wo', @_) } + + +=head1 PERFORMANCE + +To provide total flexibility L calls methods +internally while performing get/set actions, which makes it noticeably +slower than similar modules. To compensate, this module will automatically +use the insanely fast L to generate the C-group +accessors if this module is available on your system. + +=head2 Benchmark + +This is the result of a set/get/set loop benchmark on perl 5.12.1 with +thread support, showcasing most popular accessor builders: L, L, +L, L, L, +L, and L: + + Rate CAG moOse CAF moUse moo HANDMADE CAF_XS moUse_XS moo_XS CAF_XSA XSA CAG_XS + CAG 169/s -- -21% -24% -32% -32% -34% -59% -63% -67% -67% -67% -67% + moOse 215/s 27% -- -3% -13% -13% -15% -48% -53% -58% -58% -58% -58% + CAF 222/s 31% 3% -- -10% -10% -13% -46% -52% -57% -57% -57% -57% + moUse 248/s 46% 15% 11% -- -0% -3% -40% -46% -52% -52% -52% -52% + moo 248/s 46% 15% 11% 0% -- -3% -40% -46% -52% -52% -52% -52% + HANDMADE 255/s 50% 18% 14% 3% 3% -- -38% -45% -50% -51% -51% -51% + CAF_XS 411/s 143% 91% 85% 66% 66% 61% -- -11% -20% -20% -21% -21% + moUse_XS 461/s 172% 114% 107% 86% 86% 81% 12% -- -10% -11% -11% -11% + moo_XS 514/s 204% 139% 131% 107% 107% 102% 25% 12% -- -0% -1% -1% + CAF_XSA 516/s 205% 140% 132% 108% 108% 103% 26% 12% 0% -- -0% -0% + XSA 519/s 206% 141% 133% 109% 109% 104% 26% 13% 1% 0% -- -0% + CAG_XS 519/s 206% 141% 133% 109% 109% 104% 26% 13% 1% 0% 0% -- + +Benchmark program is available in the root of the +L: + +=head2 Notes on Class::XSAccessor + +You can force (or disable) the use of L before creating a +particular C accessor by either manipulating the global variable +C<$Class::Accessor::Grouped::USE_XS> to true or false (preferably with +L, or you can do so before runtime via the +C environment variable. + +Since L has no knowledge of L and +L this module does its best to detect if you are overriding +one of these methods and will fall back to using the perl version of the +accessor in order to maintain consistency. However be aware that if you +enable use of C (automatically or explicitly), create +an object, invoke a simple accessor on that object, and B manipulate +the symbol table to install a C override - you get to keep +all the pieces. =head1 AUTHORS Matt S. Trout + Christopher H. Laco -With contributions from: +=head1 CONTRIBUTORS + +Caelum: Rafael Kitover + +frew: Arthur Axel "fREW" Schmidt + +groditi: Guillermo Roditi + +Jason Plum + +ribasushi: Peter Rabbitson -Guillermo Roditi =head1 COPYRIGHT & LICENSE -Copyright (c) 2006-2009 Matt S. Trout +Copyright (c) 2006-2010 Matt S. Trout This program is free software; you can redistribute it and/or modify it under the same terms as perl itself. =cut + +######################################################################## +######################################################################## +######################################################################## +# +# Here be many angry dragons +# (all code is in private coderefs since everything inherits CAG) +# +######################################################################## +######################################################################## + +# Autodetect unless flag supplied +my $xsa_autodetected; +if (! defined $USE_XS) { + $USE_XS = __CAG_ENV__::NO_CXSA ? 0 : 1; + $xsa_autodetected++; +} + +my $perlstring; +if ($] < '5.008') { + require Data::Dumper; + my $d = Data::Dumper->new([])->Indent(0)->Purity(0)->Pad('')->Useqq(1)->Terse(1)->Freezer('')->Toaster(''); + $perlstring = sub { $d->Values([shift])->Dump }; +} +else { + require B; + $perlstring = \&B::perlstring; +} + + +my $maker_templates = { + rw => { + cxsa_call => 'accessors', + pp_generator => sub { + # my ($group, $fieldname) = @_; + my $quoted_fieldname = $perlstring->($_[1]); + sprintf <<'EOS', ($_[0], $quoted_fieldname) x 2; + +@_ > 1 + ? shift->set_%s(%s, @_) + : shift->get_%s(%s) +EOS + + }, + }, + ro => { + cxsa_call => 'getters', + pp_generator => sub { + # my ($group, $fieldname) = @_; + my $quoted_fieldname = $perlstring->($_[1]); + sprintf <<'EOS', $_[0], $quoted_fieldname; + +@_ > 1 + ? do { + my ($meth) = (caller(0))[3] =~ /([^\:]+)$/; + my $class = length( ref($_[0]) ) ? ref($_[0]) : $_[0]; + Carp::croak( + "'$meth' cannot alter its value (read-only attribute of class $class)" + ); + } + : shift->get_%s(%s) +EOS + + }, + }, + wo => { + cxsa_call => 'setters', + pp_generator => sub { + # my ($group, $fieldname) = @_; + my $quoted_fieldname = $perlstring->($_[1]); + sprintf <<'EOS', $_[0], $quoted_fieldname; + +@_ > 1 + ? shift->set_%s(%s, @_) + : do { + my ($meth) = (caller(0))[3] =~ /([^\:]+)$/; + my $class = length( ref($_[0]) ) ? ref($_[0]) : $_[0]; + Carp::croak( + "'$meth' cannot access its value (write-only attribute of class $class)" + ); + } +EOS + + }, + }, +}; + +my $cag_eval = sub { + #my ($src, $no_warnings, $err_msg) = @_; + + my $src = sprintf "{ %s warnings; use strict; no strict 'refs'; %s }", + $_[1] ? 'no' : 'use', + $_[0], + ; + + my (@rv, $err); + { + local $@ if __CAG_ENV__::UNSTABLE_DOLLARAT; + wantarray + ? @rv = eval $src + : $rv[0] = eval $src + ; + $err = $@ if $@ ne ''; + } + + Carp::croak(join ': ', ($_[2] || 'String-eval failed'), "$err\n$src\n" ) + if defined $err; + + wantarray ? @rv : $rv[0]; +}; + +my ($accessor_maker_cache, $no_xsa_warned_classes); + +# can't use pkg_gen to track this stuff, as it doesn't +# detect superclass mucking +my $original_simple_getter = __PACKAGE__->can ('get_simple'); +my $original_simple_setter = __PACKAGE__->can ('set_simple'); + +# Note!!! Unusual signature +$gen_accessor = sub { + my ($type, $class, $group, $field, $methname) = @_; + $class = ref $class if length ref $class; + + # When installing an XSA simple accessor, we need to make sure we are not + # short-circuiting a (compile or runtime) get_simple/set_simple override. + # What we do here is install a lazy first-access check, which will decide + # the ultimate coderef being placed in the accessor slot + # + # Also note that the *original* class will always retain this shim, as + # different branches inheriting from it may have different overrides. + # Thus the final method (properly labeled and all) is installed in the + # calling-package's namespace + if ($USE_XS and $group eq 'simple') { + die sprintf( "Class::XSAccessor requested but not available:\n%s\n", __CAG_ENV__::NO_CXSA ) + if __CAG_ENV__::NO_CXSA; + + my ($expected_cref, $cached_implementation); + my $ret = $expected_cref = sub { + my $current_class = length (ref ($_[0] ) ) ? ref ($_[0]) : $_[0]; + + # $cached_implementation will be set only if the shim got + # 'around'ed, in which case it is handy to avoid re-running + # this block over and over again + my $resolved_implementation = $cached_implementation->{$current_class} || do { + if ( + ($current_class->can('get_simple')||0) == $original_simple_getter + && + ($current_class->can('set_simple')||0) == $original_simple_setter + ) { + # nothing has changed, might as well use the XS crefs + # + # note that by the time this code executes, we already have + # *objects* (since XSA works on 'simple' only by definition). + # If someone is mucking with the symbol table *after* there + # are some objects already - look! many, shiny pieces! :) + # + # The weird breeder thingy is because XSA does not have an + # interface returning *just* a coderef, without installing it + # anywhere :( + Class::XSAccessor->import( + replace => 1, + class => '__CAG__XSA__BREEDER__', + $maker_templates->{$type}{cxsa_call} => { + $methname => $field, + }, + ); + __CAG__XSA__BREEDER__->can($methname); + } + else { + if (! $xsa_autodetected and ! $no_xsa_warned_classes->{$current_class}++) { + # not using Carp since the line where this happens doesn't mean much + warn 'Explicitly requested use of Class::XSAccessor disabled for objects of class ' + . "'$current_class' inheriting from '$class' due to an overriden get_simple and/or " + . "set_simple\n"; + } + + do { + # that's faster than local + $USE_XS = 0; + my $c = $gen_accessor->($type, $class, 'simple', $field, $methname); + $USE_XS = 1; + $c; + }; + } + }; + + # if after this shim was created someone wrapped it with an 'around', + # we can not blindly reinstall the method slot - we will destroy the + # wrapper. Silently chain execution further... + if ( !$expected_cref or $expected_cref != ($current_class->can($methname)||0) ) { + + # there is no point in re-determining it on every subsequent call, + # just store for future reference + $cached_implementation->{$current_class} ||= $resolved_implementation; + + # older perls segfault if the cref behind the goto throws + # http://rt.perl.org/rt3/Public/Bug/Display.html?id=35878 + return $resolved_implementation->(@_) if __CAG_ENV__::BROKEN_GOTO; + + goto $resolved_implementation; + } + + if (__CAG_ENV__::TRACK_UNDEFER_FAIL) { + my $deferred_calls_seen = do { + no strict 'refs'; + \%{"${current_class}::__cag_deferred_xs_shim_invocations"} + }; + my @cframe = caller(0); + if (my $already_seen = $deferred_calls_seen->{$cframe[3]}) { + Carp::carp ( + "Deferred version of method $cframe[3] invoked more than once (originally " + . "invoked at $already_seen). This is a strong indication your code has " + . 'cached the original ->can derived method coderef, and is using it instead ' + . 'of the proper method re-lookup, causing minor performance regressions' + ); + } + else { + $deferred_calls_seen->{$cframe[3]} = "$cframe[1] line $cframe[2]"; + } + } + + # install the resolved implementation into the code slot so we do not + # come here anymore (hopefully) + # since XSAccessor was available - so is Sub::Name + { + no strict 'refs'; + no warnings 'redefine'; + + my $fq_name = "${current_class}::${methname}"; + *$fq_name = Sub::Name::subname($fq_name, $resolved_implementation); + + # need to update what the shim expects too *in case* its + # ->can was cached for some moronic reason + $expected_cref = $resolved_implementation; + Scalar::Util::weaken($expected_cref); + } + + # older perls segfault if the cref behind the goto throws + # http://rt.perl.org/rt3/Public/Bug/Display.html?id=35878 + return $resolved_implementation->(@_) if __CAG_ENV__::BROKEN_GOTO; + + goto $resolved_implementation; + }; + + Scalar::Util::weaken($expected_cref); # to break the self-reference + $ret; + } + + # no Sub::Name - just install the coderefs directly (compiling every time) + elsif (__CAG_ENV__::NO_SUBNAME) { + my $src = $accessor_maker_cache->{source}{$type}{$group}{$field} ||= + $maker_templates->{$type}{pp_generator}->($group, $field); + + $cag_eval->( + "no warnings 'redefine'; sub ${class}::${methname} { $src }; 1", + ); + + undef; # so that no further attempt will be made to install anything + } + + # a coderef generator with a variable pad (returns a fresh cref on every invocation) + else { + ($accessor_maker_cache->{pp}{$type}{$group}{$field} ||= do { + my $src = $accessor_maker_cache->{source}{$type}{$group}{$field} ||= + $maker_templates->{$type}{pp_generator}->($group, $field); + + $cag_eval->( "sub { my \$dummy; sub { \$dummy if 0; $src } }" ); + })->() + } +}; + +1;