Class::XSAccessor::Array(3pm)

NAME

Class::XSAccessor::Array - Generate fast XS accessors without runtime
compilation

SYNOPSIS

package MyClassUsingArraysAsInternalStorage;
use Class::XSAccessor::Array
  constructor => 'new',
  getters => {
    get_foo => 0, # 0 is the array index to access
    get_bar => 1,
  },
  setters => {
    set_foo => 0,
    set_bar => 1,
  },
  accessors => { # a mutator
    buz => 2,
  },
  predicates => { # test for definedness
    has_buz => 2,
  },
  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 you prefer it,
# which can also help PerlTidy to flow the statement correctly.
use Class::XSAccessor {
  getters => {
    get_foo => 0,
    get_bar => 1,
  },
};

DESCRIPTION

The module implements fast XS accessors both for getting at and setting an object attribute. Additionally, the module supports mutators and
simple predicates ("has_foo()" like tests for definedness of an
attributes). The module works only with objects that are implemented
as arrays. Using it on hash-based objects is bound to make your life miserable. Refer to Class::XSAccessor for an implementation that works with hash-based objects.

A simple benchmark showed more than a factor of two performance
advantage over writing accessors in Perl.

Since version 0.10, the module can also generate simple constructors (implemented in XS) for you. Simply supply the "constructor => 'constructor_name'" option or the "constructors => ['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. Note that any parameters to new() will be discarded! If there is a better idiom for array-based objects, let me know.
While generally more obscure than hash-based objects, objects using blessed arrays as internal representation are a bit faster as its somewhat faster to access arrays than hashes. Accordingly, this module is slightly faster (~10-15%) than Class::XSAccessor, which works on hash-based objects.
The method names may be fully qualified. In the example of the synopsis, you could have written "MyClass::get_foo" instead of "get_foo". This way, you can install methods in classes other than the current class. See also: The "class" option below.
Since version 1.01, you 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 think of a large class hierarchy with interfaces such as PPI. This is implemented as the "true" and "false" options, see synopsis.

OPTIONS

In addition to specifying the types and names of accessors, you can add options which modify behaviour. The options are specified as key/value pairs just as the accessor declaration. Example:: use Class::XSAccessor::Array
getters => {
get_foo => 0,

},
replace => 1;; The list of available options is:
replace: Set this to a true value to prevent "Class::XSAccessor::Array" from
complaining about replacing existing subroutines.
chained: Set this to a true value to change the return value of setters and
mutators (when called with an argument). If "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, "chained" affects all methods generated in
the same "use Class::XSAccessor::Array ..." statement.
class: By default, the accessors are generated in the calling class. Using the "class" option, you can explicitly specify where the methods are to be generated.

CAVEATS

Probably wouldn't work if your objects are tied. 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 or array index that's only known at runtime. Note that compiling C code at run-time a la Inline::C is a no go.

Threading. With version 1.00, a memory leak has been fixed that would leak a small amount of memory if you loaded "Class::XSAccessor"-based
classes in a subthread that hadn't been loaded in the "main" thread
before. If the subthread then terminated, a hash key and an int per
associated method used ot be lost. Note that this mattered only if
classes were only loaded in a sort of throw-away thread.

In the new implementation as of 1.00, the memory will not be released
again either in the above situation. But it will be recycled when the
same class or a similar class is loaded again in any thread.

AUTHOR

Steffen Mueller <smueller@cpan.org>

COPYRIGHT AND LICENSE

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.

docs.sk

comprehensive documentation repository

Most Viewed