NAME
FFI::Platypus::Legacy::Raw - Perl bindings to the portable FFI library
(libffi)
VERSION
version 0.06
SYNOPSIS
use FFI::Platypus::Legacy::Raw;
my $cos = FFI::Platypus::Legacy::Raw->new(
'libm.so', 'cos',
FFI::Platypus::Legacy::Raw::double, # return value
FFI::Platypus::Legacy::Raw::double # arg #1
);
say $cos->call(2.0);
DESCRIPTION
FFI::Platypus::Legacy::Raw and friends are a fork of FFI::Raw that uses
FFI::Platypus instead of FFI::Raw's own libffi implementation. It is
intended for use when migrating from FFI::Raw to FFI::Platypus. The
main reason one might have for switching from Raw to Platypus is
because Platypus is actively maintained, provides a more powerful
interface, can be much faster when functions are "attached", and works
on more platforms than Raw. This module should be a drop in replacement
for FFI::Raw, simply replace all instances of FFI::Raw to
FFI::Platypus::Legacy::Raw. See also Alt::FFI::Raw::Platypus for a way
to use this module without making any source code changes.
FFI::Platypus::Legacy::Raw provides a low-level foreign function
interface (FFI) for Perl based on libffi
. In essence, it can access and call
functions exported by shared libraries without the need to write C/XS
code.
Dynamic symbols can be automatically resolved at runtime so that the
only information needed to use FFI::Platypus::Legacy::Raw is the name
(or path) of the target library, the name of the function to call and
its signature (though it is also possible to pass a function pointer
obtained, for example, using DynaLoader).
Note that this module has nothing to do with FFI.
CONSTRUCTORS
new
my $ffi = FFI::Platypus::Legacy::Raw->new( $library, $function, $return_type, @arg_types )
Create a new FFI::Platypus::Legacy::Raw object. It loads $library,
finds the function $function with return type $return_type and creates
a calling interface.
If $library is undef then the function is searched in the main program.
This method also takes a variable number of types, representing the
arguments of the wanted function.
new_from_ptr
my $ffi = FFI::Platypus::Legacy::Raw->new_from_ptr( $function_ptr, $return_type, @arg_types )
Create a new FFI::Platypus::Legacy::Raw object from the $function_ptr
function pointer.
This method also takes a variable number of types, representing the
arguments of the wanted function.
METHODS
call
my $ret = $ffi->call( @args)
Execute the FFI::Platypus::Legacy::Raw function. This method also takes
a variable number of arguments, which are passed to the called
function. The argument types must match the types passed to new (or
new_from_ptr).
The FFI::Platypus::Legacy::Raw object can be used as a CODE reference
as well. Dereferencing the object will work just like call():
$cos->call(2.0); # normal call() call
$cos->(2.0); # dereference as CODE ref
This works because FFI::Platypus::Legacy::Raw overloads the &{}
operator.
coderef
my $code = FFI::Platypus::Legacy::Raw->coderef;
Return a code reference of a given FFI::Platypus::Legacy::Raw.
SUBROUTINES
memptr
my $memptr = FFI::Platypus::Legacy::Raw::memptr( $length );
Create a FFI::Platypus::Legacy::Raw::MemPtr. This is a shortcut for
FFI::Platypus::Legacy::Raw::MemPtr->new(...).
callback
my $callback = FFI::Platypus::Legacy::Raw::callback( $coderef, $ret_type, \@arg_types );
Create a FFI::Platypus::Legacy::Raw::Callback. This is a shortcut for
FFI::Platypus::Legacy::Raw::Callback->new(...).
TYPES
Caveats on the way types were defined by the original FFI::Raw:
This module uses the common convention that char is 8 bits, short is 16
bits, int is 32 bits, long is 32 bits on a 32bit arch and 64 bits on a
64 bit arch, int64 is 64 bits. While this is probably true on most
modern platforms (if not all), it isn't technically guaranteed by the
standard. FFI::Platypus itself, differs in that int, long, etc are the
native sizes, even if they do not follow this common convention and you
need to use sint32, sint64, etc if you want a specific sized type.
This module also assumes that char is signed. Although this is commonly
true on many platforms it is not guaranteed by the standard. On
Windows, for example the char type is unsigned. FFI::Platypus by
contrast follows to the standard where char uses the native behavior,
and if you want an signed character type you can use sint8 instead.
void
my $type = FFI::Platypus::Legacy::Raw::void();
Return a FFI::Platypus::Legacy::Raw void type.
int
my $type = FFI::Platypus::Legacy::Raw::int();
Return a FFI::Platypus::Legacy::Raw integer type.
uint
my $type = FFI::Platypus::Legacy::Raw::uint();
Return a FFI::Platypus::Legacy::Raw unsigned integer type.
short
my $type = FFI::Platypus::Legacy::Raw::short();
Return a FFI::Platypus::Legacy::Raw short integer type.
ushort
my $type = FFI::Platypus::Legacy::Raw::ushort();
Return a FFI::Platypus::Legacy::Raw unsigned short integer type.
long
my $type = FFI::Platypus::Legacy::Raw::long();
Return a FFI::Platypus::Legacy::Raw long integer type.
ulong
my $type = FFI::Platypus::Legacy::Raw::ulong();
Return a FFI::Platypus::Legacy::Raw unsigned long integer type.
int64
my $type = FFI::Platypus::Legacy::Raw::int64();
Return a FFI::Platypus::Legacy::Raw 64 bit integer type. This requires
Math::Int64 to work.
uint64
my $type = FFI::Platypus::Legacy::Raw::uint64();
Return a FFI::Platypus::Legacy::Raw unsigned 64 bit integer type. This
requires Math::Int64 to work.
char
my $type = FFI::Platypus::Legacy::Raw::char();
Return a FFI::Platypus::Legacy::Raw char type.
uchar
my $type = FFI::Platypus::Legacy::Raw::uchar();
Return a FFI::Platypus::Legacy::Raw unsigned char type.
float
my $type = FFI::Platypus::Legacy::Raw::float();
Return a FFI::Platypus::Legacy::Raw float type.
double
my $type = FFI::Platypus::Legacy::Raw::double();
Return a FFI::Platypus::Legacy::Raw double type.
str
my $type = FFI::Platypus::Legacy::Raw::str();
Return a FFI::Platypus::Legacy::Raw string type.
ptr
my $type = FFI::Platypus::Legacy::Raw::ptr();
Return a FFI::Platypus::Legacy::Raw pointer type.
EXTENSIONS
Documented in this section are features that are available when using
FFI::Platypus::Legacy::Raw, but are NOT provided by FFI::Raw. Only use
them if you do not intend on switching back to FFI::Raw.
attach
$ffi->attach; # allowed for functions specified by name
# but not by address/pointer
$ffi->attach($name);
$ffi->attach($name, $prototype);
Attach the function as an xsub. This is probably the most important
feature that FFI::Platypus provides that FFI::Raw does not. calling an
attached xsub is much faster than calling an unattached function.
platypus
my $ffi = FFI::Platypus::Legacy::Raw->platypus($library);
Returns the FFI::Platypus instance used internally by this module. This
can be useful to customize for your particular library. Adding types
can be useful.
my $lib = 'libfoo.so';
my $ffi = FFI::Platypus::Legacy::Raw->platypus($lib);
$ffi->type('int[42]' => 'my_int_42');
my $f = FFI::Platypus::Legacy::Raw->new(
$lib, 'my_array_sum',
'int', 'my_int_64',
);
my $sum = $f->call([1..42]);
You CANNOT get the platypus instance for undef (libc and other codes
already linked into the currently running Perl) using this interface,
as that is somewhat "global" and adding types or other customizations
there could break other modules.
mix and match types
You can mix and match FFI::Raw and FFI::Platypus types. The main
benefit is that you get the more rigorous type system as described
above in the TYPES caveat.
There is an overhead to the FFI::Platypus::Legacy:Raw::ptr type in
order to handle the various pointer types (
FFI::Platypus::Legacy::Raw::Ptr, FFI::Platypus::Legacy::Raw::MemPtr,
FFI::Platypus::Legacy::Raw::Callback). If you aren't using those
classes, then you can save a few cycles by instead using the Platypus
opaque type.
SEE ALSO
FFI::Platypus, Alt::FFI::Raw::Platypus
AUTHOR
Original author: Alessandro Ghedini (ghedo, ALEXBIO)
Current maintainer: Graham Ollis
Contributors:
Bakkiaraj Murugesan (bakkiaraj)
Dylan Cali (CALID)
Brian Wightman (MidLifeXis, MLX)
David Steinbrunner (dsteinbrunner)
Olivier Mengué (DOLMEN)
COPYRIGHT AND LICENSE
This software is copyright (c) 2012 by Alessandro Ghedini.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.