X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fnamespace%2Fclean.pm;h=0d738ad30015e26bd376b482083439245673b5dc;hb=043124941be4ff69a092e2090db8482c76ea5bb1;hp=9d7268f328cc88e4745a0e2b191188e3a246f515;hpb=53e92ec5277d51ae5e1726f8153b87353bb14665;p=p5sagit%2Fnamespace-clean.git diff --git a/lib/namespace/clean.pm b/lib/namespace/clean.pm index 9d7268f..0d738ad 100644 --- a/lib/namespace/clean.pm +++ b/lib/namespace/clean.pm @@ -1,26 +1,16 @@ package namespace::clean; - -=head1 NAME - -namespace::clean - Keep imports and functions out of your namespace - -=cut +# ABSTRACT: Keep imports and functions out of your namespace use warnings; use strict; -use vars qw( $VERSION $STORAGE_VAR ); -use Symbol qw( qualify_to_ref ); -use Filter::EOF; +use vars qw( $STORAGE_VAR $SCOPE_HOOK_KEY $SCOPE_EXPLICIT ); +use Sub::Name 0.04 qw(subname); +use Sub::Identify 0.04 qw(sub_fullname); +use Package::Stash 0.03; +use B::Hooks::EndOfScope 0.07; -=head1 VERSION - -0.04 - -=cut - -$VERSION = 0.04; -$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; +$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; =head1 SYNOPSIS @@ -55,10 +45,12 @@ $STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE'; =head1 DESCRIPTION +=head2 Keeping packages clean + When you define a function, or import one, into a Perl package, it will naturally also be available as a method. This does not per se cause problems, but it can complicate subclassing and, for example, plugin -classes that are included via multiple inheritance by loading them as +classes that are included via multiple inheritance by loading them as base classes. The C pragma will remove all previously declared or @@ -70,74 +62,185 @@ By unimporting via C you can tell C to start collecting functions for the next C specification. You can use the C<-except> flag to tell C that you -don't want it to remove a certain function. A common use would be a -module exporting an C method along with some functions: +don't want it to remove a certain function or method. A common use would +be a module exporting an C method along with some functions: use ModuleExportingImport; use namespace::clean -except => [qw( import )]; -=head1 METHODS +If you just want to C<-except> a single sub, you can pass it directly. +For more than one value you have to use an array reference. -You shouldn't need to call any of these. Just C the package at the -appropriate place. +=head2 Explicitely removing functions when your scope is compiled -=cut +It is also possible to explicitely tell C what packages +to remove when the surrounding scope has finished compiling. Here is an +example: -=head2 import + package Foo; + use strict; -Makes a snapshot of the current defined functions and registers a -L cleanup routine to remove those symbols at the end -of the compile-time. + # blessed NOT available -=cut + sub my_class { + use Scalar::Util qw( blessed ); + use namespace::clean qw( blessed ); -sub import { - my ($pragma, %args) = @_; + # blessed available + return blessed shift; + } - # calling class, all current functions and our storage - my $cleanee = caller; - my $functions = $pragma->get_functions($cleanee); - my $store = $pragma->get_class_store($cleanee); + # blessed NOT available - my %except = map {( $_ => 1 )} @{ $args{ -except } || [] }; +=head2 Moose - # register symbols for removal, if they have a CODE entry - for my $f (keys %$functions) { - next if $except{ $f }; - next unless $functions->{ $f } - and *{ $functions->{ $f } }{CODE}; - $store->{remove}{ $f } = 1; - } +When using C together with L you want to keep +the installed C method. So your classes should look like: + + package Foo; + use Moose; + use namespace::clean -except => 'meta'; + ... + +Same goes for L. + +=head2 Cleaning other packages + +You can tell C that you want to clean up another package +instead of the one importing. To do this you have to pass in the C<-cleanee> +option like this: + + package My::MooseX::namespace::clean; + use strict; - # register EOF handler on first call to import - unless ($store->{handler_is_installed}) { - Filter::EOF->on_eof_call(sub { - SYMBOL: - for my $f (keys %{ $store->{remove} }) { - - # ignore already removed symbols - next SYMBOL if $store->{exclude}{ $f }; - no strict 'refs'; - - # keep original value to restore non-code slots - local *__tmp = *{ ${ "${cleanee}::" }{ $f } }; - delete ${ "${cleanee}::" }{ $f }; - - SLOT: - # restore non-code slots to symbol - for my $t (qw( SCALAR ARRAY HASH IO FORMAT )) { - next SLOT unless defined *__tmp{ $t }; - *{ "${cleanee}::$f" } = *__tmp{ $t }; - } + use namespace::clean (); # no cleanup, just load + + sub import { + namespace::clean->import( + -cleanee => scalar(caller), + -except => 'meta', + ); + } + +If you don't care about Cs discover-and-C<-except> logic, and +just want to remove subroutines, try L. + +=method clean_subroutines + +This exposes the actual subroutine-removal logic. + + namespace::clean->clean_subroutines($cleanee, qw( subA subB )); + +will remove C and C from C<$cleanee>. Note that this will remove the +subroutines B and not wait for scope end. If you want to have this +effect at a specific time (e.g. C acts on scope compile end) +it is your responsibility to make sure it runs at that time. + +=cut + +my $RemoveSubs = sub { + + my $cleanee = shift; + my $store = shift; + my $cleanee_stash = Package::Stash->new($cleanee); + my $deleted_stash = Package::Stash->new("namespace::clean::deleted::$cleanee"); + SYMBOL: + for my $f (@_) { + my $variable = "&$f"; + # ignore already removed symbols + next SYMBOL if $store->{exclude}{ $f }; + + next SYMBOL unless $cleanee_stash->has_package_symbol($variable); + + if (ref(\$cleanee_stash->namespace->{$f}) eq 'GLOB') { + # convince the Perl debugger to work + # it assumes that sub_fullname($sub) can always be used to find the CV again + # since we are deleting the glob where the subroutine was originally + # defined, that assumption no longer holds, so we need to move it + # elsewhere and point the CV's name to the new glob. + my $sub = $cleanee_stash->get_package_symbol($variable); + if ( sub_fullname($sub) eq ($cleanee_stash->name . "::$f") ) { + my $new_fq = $deleted_stash->name . "::$f"; + subname($new_fq, $sub); + $deleted_stash->add_package_symbol($variable, $sub); } - }); - $store->{handler_is_installed} = 1; + } + + $cleanee_stash->remove_package_symbol($variable); } +}; - return 1; +sub clean_subroutines { + my ($nc, $cleanee, @subs) = @_; + $RemoveSubs->($cleanee, {}, @subs); } -=head2 unimport +=method import + +Makes a snapshot of the current defined functions and installs a +L hook in the current scope to invoke the cleanups. + +=cut + +sub import { + my ($pragma, @args) = @_; + + my (%args, $is_explicit); + + ARG: + while (@args) { + + if ($args[0] =~ /^\-/) { + my $key = shift @args; + my $value = shift @args; + $args{ $key } = $value; + } + else { + $is_explicit++; + last ARG; + } + } + + my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller; + if ($is_explicit) { + on_scope_end { + $RemoveSubs->($cleanee, {}, @args); + }; + } + else { + + # calling class, all current functions and our storage + my $functions = $pragma->get_functions($cleanee); + my $store = $pragma->get_class_store($cleanee); + my $stash = Package::Stash->new($cleanee); + + # except parameter can be array ref or single value + my %except = map {( $_ => 1 )} ( + $args{ -except } + ? ( ref $args{ -except } eq 'ARRAY' ? @{ $args{ -except } } : $args{ -except } ) + : () + ); + + # register symbols for removal, if they have a CODE entry + for my $f (keys %$functions) { + next if $except{ $f }; + next unless $stash->has_package_symbol("&$f"); + $store->{remove}{ $f } = 1; + } + + # register EOF handler on first call to import + unless ($store->{handler_is_installed}) { + on_scope_end { + $RemoveSubs->($cleanee, $store, keys %{ $store->{remove} }); + }; + $store->{handler_is_installed} = 1; + } + + return 1; + } +} + +=method unimport This method will be called when you do a @@ -148,10 +251,10 @@ It will start a new section of code that defines functions to clean up. =cut sub unimport { - my ($pragma) = @_; + my ($pragma, %args) = @_; # the calling class, the current functions and our storage - my $cleanee = caller; + my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller; my $functions = $pragma->get_functions($cleanee); my $store = $pragma->get_class_store($cleanee); @@ -165,20 +268,20 @@ sub unimport { return 1; } -=head2 get_class_store +=method get_class_store -This returns a reference to a hash in a passed package containing +This returns a reference to a hash in a passed package containing information about function names included and excluded from removal. =cut sub get_class_store { my ($pragma, $class) = @_; - no strict 'refs'; - return \%{ "${class}::${STORAGE_VAR}" }; + my $stash = Package::Stash->new($class); + return $stash->get_package_symbol("%$STORAGE_VAR"); } -=head2 get_functions +=method get_functions Takes a class as argument and returns all currently defined functions in it as a hash reference with the function name as key and a typeglob @@ -189,24 +292,23 @@ reference to the symbol as value. sub get_functions { my ($pragma, $class) = @_; + my $stash = Package::Stash->new($class); return { - map { @$_ } # key => value - grep { *{ $_->[1] }{CODE} } # only functions - map { [$_, qualify_to_ref( $_, $class )] } # get globref - grep { $_ !~ /::$/ } # no packages - do { no strict 'refs'; keys %{ "${class}::" } } # symbol entries + map { $_ => $stash->get_package_symbol("&$_") } + $stash->list_all_package_symbols('CODE') }; } =head1 IMPLEMENTATION DETAILS -This module works through the effect that a +This module works through the effect that a delete $SomePackage::{foo}; will remove the C symbol from C<$SomePackage> for run time lookups (e.g., method calls) but will leave the entry alive to be called by -already resolved names in the package itself. +already resolved names in the package itself. C will +restore and therefor in effect keep all glob slots that aren't C. A test file has been added to the perl core to ensure that this behaviour will be stable in future releases. @@ -216,18 +318,13 @@ use C instead. =head1 SEE ALSO -L - -=head1 AUTHOR AND COPYRIGHT - -Robert 'phaylon' Sedlacek Crs@474.atE>, with many thanks to -Matt S Trout for the inspiration on the whole idea. +L -=head1 LICENSE +=head1 THANKS -This program is free software; you can redistribute it and/or modify -it under the same terms as perl itself. +Many thanks to Matt S Trout for the inspiration on the whole idea. =cut -1; +no warnings; +'Danger! Laws of Thermodynamics may not apply.'