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package Class::XSAccessor;
use 5.008;
use strict;
use warnings;
use Carp qw/croak/;
use Class::XSAccessor::Heavy;
use XSLoader;
our $VERSION = '1.19';
XSLoader::load('Class::XSAccessor', $VERSION);
sub _make_hash {
my $ref = shift;
if (ref ($ref)) {
if (ref($ref) eq 'ARRAY') {
$ref = { map { $_ => $_ } @$ref }
}
} else {
$ref = { $ref, $ref };
}
return $ref;
}
sub import {
my $own_class = shift;
my ($caller_pkg) = caller();
# Support both { getters => ... } and plain getters => ...
my %opts = ref($_[0]) eq 'HASH' ? %{$_[0]} : @_;
$caller_pkg = $opts{class} if defined $opts{class};
# TODO: Refactor. Move more duplicated code to ::Heavy
my $read_subs = _make_hash($opts{getters} || {});
my $set_subs = _make_hash($opts{setters} || {});
my $acc_subs = _make_hash($opts{accessors} || {});
my $lvacc_subs = _make_hash($opts{lvalue_accessors} || {});
my $pred_subs = _make_hash($opts{predicates} || {});
my $ex_pred_subs = _make_hash($opts{exists_predicates} || {});
my $def_pred_subs = _make_hash($opts{defined_predicates} || {});
my $test_subs = _make_hash($opts{__tests__} || {});
my $construct_subs = $opts{constructors} || [defined($opts{constructor}) ? $opts{constructor} : ()];
my $true_subs = $opts{true} || [];
my $false_subs = $opts{false} || [];
foreach my $subtype ( ["getter", $read_subs],
["setter", $set_subs],
["accessor", $acc_subs],
["lvalue_accessor", $lvacc_subs],
["test", $test_subs],
["ex_predicate", $ex_pred_subs],
["def_predicate", $def_pred_subs],
["def_predicate", $pred_subs] )
{
my $subs = $subtype->[1];
foreach my $subname (keys %$subs) {
my $hashkey = $subs->{$subname};
_generate_method($caller_pkg, $subname, $hashkey, \%opts, $subtype->[0]);
}
}
foreach my $subtype ( ["constructor", $construct_subs],
["true", $true_subs],
["false", $false_subs] )
{
foreach my $subname (@{$subtype->[1]}) {
_generate_method($caller_pkg, $subname, "", \%opts, $subtype->[0]);
}
}
}
sub _generate_method {
my ($caller_pkg, $subname, $hashkey, $opts, $type) = @_;
croak("Cannot use undef as a hash key for generating an XS $type accessor. (Sub: $subname)")
if not defined $hashkey;
$subname = "${caller_pkg}::$subname" if $subname !~ /::/;
Class::XSAccessor::Heavy::check_sub_existence($subname) if not $opts->{replace};
no warnings 'redefine'; # don't warn about an explicitly requested redefine
if ($type eq 'getter') {
newxs_getter($subname, $hashkey);
}
elsif ($type eq 'lvalue_accessor') {
newxs_lvalue_accessor($subname, $hashkey);
}
elsif ($type eq 'setter') {
newxs_setter($subname, $hashkey, $opts->{chained}||0);
}
elsif ($type eq 'def_predicate') {
newxs_defined_predicate($subname, $hashkey);
}
elsif ($type eq 'ex_predicate') {
newxs_exists_predicate($subname, $hashkey);
}
elsif ($type eq 'constructor') {
newxs_constructor($subname);
}
elsif ($type eq 'true') {
newxs_boolean($subname, 1);
}
elsif ($type eq 'false') {
newxs_boolean($subname, 0);
}
elsif ($type eq 'test') {
newxs_test($subname, $hashkey);
}
else {
newxs_accessor($subname, $hashkey, $opts->{chained}||0);
}
}
1;
__END__
=head1 NAME
Class::XSAccessor - Generate fast XS accessors without runtime compilation
=head1 SYNOPSIS
package MyClass;
use Class::XSAccessor
replace => 1, # Replace existing methods (if any)
constructor => 'new',
getters => {
get_foo => 'foo', # 'foo' is the hash key to access
get_bar => 'bar',
},
setters => {
set_foo => 'foo',
set_bar => 'bar',
},
accessors => {
foo => 'foo',
bar => 'bar',
},
# "predicates" is an alias for "defined_predicates"
defined_predicates => {
defined_foo => 'foo',
defined_bar => 'bar',
},
exists_predicates => {
has_foo => 'foo',
has_bar => 'bar',
},
lvalue_accessors => { # see below
baz => 'baz', # ...
},
true => [ 'is_token', 'is_whitespace' ],
false => [ 'significant' ];
# The imported methods are implemented in fast XS.
# normal class code here.
As of version 1.05, some alternative syntax forms are available:
package MyClass;
# Options can be passed as a HASH reference, if preferred,
# which can also help Perl::Tidy to format the statement correctly.
use Class::XSAccessor {
# If the name => key values are always identical,
# the following shorthand can be used.
accessors => [ 'foo', 'bar' ],
};
=head1 DESCRIPTION
Class::XSAccessor implements fast read, write and read/write accessors in XS.
Additionally, it can provide predicates such as C<has_foo()> for testing
whether the attribute C<foo> exists in the object (which is different from
"is defined within the object").
It only works with objects that are implemented as ordinary hashes.
L<Class::XSAccessor::Array> implements the same interface for objects
that use arrays for their internal representation.
Since version 0.10, the module can also generate simple constructors
(implemented in XS). Simply supply the
C<constructor =E<gt> 'constructor_name'> option or the
C<constructors =E<gt> ['new', 'create', 'spawn']> option.
These constructors do the equivalent of the following Perl code:
sub new {
my $class = shift;
return bless { @_ }, ref($class)||$class;
}
That means they can be called on objects and classes but will not
clone objects entirely. Parameters to C<new()> are added to the
object.
The XS accessor methods are between 3 and 4 times faster than typical
pure-Perl accessors in some simple benchmarking.
The lower factor applies to the potentially slightly obscure
C<sub set_foo_pp {$_[0]-E<gt>{foo} = $_[1]}>, so if you usually
write clear code, a factor of 3.5 speed-up is a good estimate.
If in doubt, do your own benchmarking!
The method names may be fully qualified. The example in the synopsis could
have been written as C<MyClass::get_foo> instead
of C<get_foo>. This way, methods can be installed in classes other
than the current class. See also: the C<class> option below.
By default, the setters return the new value that was set,
and the accessors (mutators) do the same. This behaviour can be changed
with the C<chained> option - see below. The predicates return a boolean.
Since version 1.01, C<Class::XSAccessor> can generate extremely simple methods which
just return true or false (and always do so). If that seems like a
really superfluous thing to you, then consider a large class hierarchy
with interfaces such as L<PPI>. These methods are provided by the C<true>
and C<false> options - see the synopsis.
C<defined_predicates> check whether a given object attribute is defined.
C<predicates> is an alias for C<defined_predicates> for compatibility with
older versions of C<Class::XSAccessor>. C<exists_predicates> checks
whether the given attribute exists in the object using C<exists>.
=head1 OPTIONS
In addition to specifying the types and names of accessors, additional options
can be supplied which modify behaviour. The options are specified as key/value pairs
in the same manner as the accessor declaration. For example:
use Class::XSAccessor
getters => {
get_foo => 'foo',
},
replace => 1;
The list of available options is:
=head2 replace
Set this to a true value to prevent C<Class::XSAccessor> from
complaining about replacing existing subroutines.
=head2 chained
Set this to a true value to change the return value of setters
and mutators (when called with an argument).
If C<chained> is enabled, the setters and accessors/mutators will
return the object. Mutators called without an argument still
return the value of the associated attribute.
As with the other options, C<chained> affects all methods generated
in the same C<use Class::XSAccessor ...> statement.
=head2 class
By default, the accessors are generated in the calling class. The
the C<class> option allows the target class to be specified.
=head1 LVALUES
Support for lvalue accessors via the keyword C<lvalue_accessors>
was added in version 1.08. At this point, B<THEY ARE CONSIDERED HIGHLY
EXPERIMENTAL>. Furthermore, their performance hasn't been benchmarked
yet.
The following example demonstrates an lvalue accessor:
package Address;
use Class::XSAccessor
constructor => 'new',
lvalue_accessors => { zip_code => 'zip' };
package main;
my $address = Address->new(zip => 2);
print $address->zip_code, "\n"; # prints 2
$address->zip_code = 76135; # <--- This is it!
print $address->zip_code, "\n"; # prints 76135
=head1 CAVEATS
Probably won't work for objects based on I<tied> hashes. But that's a strange thing to do anyway.
Scary code exploiting strange XS features.
If you think writing an accessor in XS should be a laughably simple exercise, then
please contemplate how you could instantiate a new XS accessor for a new hash key
that's only known at run-time. Note that compiling C code at run-time a la L<Inline::C|Inline::C>
is a no go.
Threading. With version 1.00, a memory leak has been B<fixed>. Previously, a small amount of
memory would leak if C<Class::XSAccessor>-based classes were loaded in a subthread without having
been loaded in the "main" thread. If the subthread then terminated, a hash key and an int per
associated method used to be lost. Note that this mattered only if classes were B<only> loaded
in a sort of throw-away thread.
In the new implementation, as of 1.00, the memory will still not be released, in the same situation,
but it will be recycled when the same class, or a similar class, is loaded again in B<any> thread.
=head1 SEE ALSO
=over
=item * L<Class::XSAccessor::Array>
=item * L<AutoXS>
=back
=head1 AUTHOR
Steffen Mueller E<lt>smueller@cpan.orgE<gt>
chocolateboy E<lt>chocolate@cpan.orgE<gt>
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013 by Steffen Mueller
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8 or,
at your option, any later version of Perl 5 you may have available.
=cut