| File | /opt/wise/lib/perl5/5.10.0/AutoLoader.pm | Statements Executed | 122 | Total Time | 0.003419 seconds |
| Calls | P | F | Exclusive Time |
Inclusive Time |
Subroutine | |
|---|---|---|---|---|---|---|
| 6 | 6 | 4 | 0.00127 | 0.00127 | AutoLoader:: | import |
| 1 | 1 | 1 | 8.3e-5 | 8.3e-5 | AutoLoader:: | find_filename |
| 0 | 0 | 0 | 0 | 0 | AutoLoader:: | AUTOLOAD |
| 0 | 0 | 0 | 0 | 0 | AutoLoader:: | BEGIN |
| 0 | 0 | 0 | 0 | 0 | AutoLoader:: | __ANON__[:31] |
| 0 | 0 | 0 | 0 | 0 | AutoLoader:: | can |
| 0 | 0 | 0 | 0 | 0 | AutoLoader:: | unimport |
| Line | Stmts. | Exclusive Time | Avg. | Code |
|---|---|---|---|---|
| 1 | package AutoLoader; | |||
| 2 | ||||
| 3 | 3 | 2.5e-5 | 8.3e-6 | use strict; # spent 8µs making 1 call to strict::import |
| 4 | 3 | 0.00011 | 3.6e-5 | use 5.006_001; |
| 5 | ||||
| 6 | 1 | 1.0e-6 | 1.0e-6 | our($VERSION, $AUTOLOAD); |
| 7 | ||||
| 8 | 1 | 0 | 0 | my $is_dosish; |
| 9 | 1 | 1.0e-6 | 1.0e-6 | my $is_epoc; |
| 10 | 1 | 1.0e-6 | 1.0e-6 | my $is_vms; |
| 11 | 1 | 0 | 0 | my $is_macos; |
| 12 | ||||
| 13 | BEGIN { | |||
| 14 | 5 | 7.0e-6 | 1.4e-6 | $is_dosish = $^O eq 'dos' || $^O eq 'os2' || $^O eq 'MSWin32' || $^O eq 'NetWare'; |
| 15 | $is_epoc = $^O eq 'epoc'; | |||
| 16 | $is_vms = $^O eq 'VMS'; | |||
| 17 | $is_macos = $^O eq 'MacOS'; | |||
| 18 | $VERSION = '5.63'; | |||
| 19 | 1 | 0.00011 | 0.00011 | } |
| 20 | ||||
| 21 | AUTOLOAD { | |||
| 22 | 10 | 0.00068 | 6.8e-5 | my $sub = $AUTOLOAD; |
| 23 | my $filename = AutoLoader::find_filename( $sub ); # spent 83µs making 1 call to AutoLoader::find_filename | |||
| 24 | ||||
| 25 | my $save = $@; | |||
| 26 | local $!; # Do not munge the value. | |||
| 27 | eval { local $SIG{__DIE__}; require $filename }; | |||
| 28 | if ($@) { | |||
| 29 | if (substr($sub,-9) eq '::DESTROY') { | |||
| 30 | 3 | 0.00029 | 9.7e-5 | no strict 'refs'; # spent 22µs making 1 call to strict::unimport |
| 31 | *$sub = sub {}; | |||
| 32 | $@ = undef; | |||
| 33 | } elsif ($@ =~ /^Can't locate/) { | |||
| 34 | # The load might just have failed because the filename was too | |||
| 35 | # long for some old SVR3 systems which treat long names as errors. | |||
| 36 | # If we can successfully truncate a long name then it's worth a go. | |||
| 37 | # There is a slight risk that we could pick up the wrong file here | |||
| 38 | # but autosplit should have warned about that when splitting. | |||
| 39 | if ($filename =~ s/(\w{12,})\.al$/substr($1,0,11).".al"/e){ | |||
| 40 | eval { local $SIG{__DIE__}; require $filename }; | |||
| 41 | } | |||
| 42 | } | |||
| 43 | if ($@){ | |||
| 44 | $@ =~ s/ at .*\n//; | |||
| 45 | my $error = $@; | |||
| 46 | require Carp; | |||
| 47 | Carp::croak($error); | |||
| 48 | } | |||
| 49 | } | |||
| 50 | $@ = $save; | |||
| 51 | goto &$sub; | |||
| 52 | } | |||
| 53 | ||||
| 54 | sub can { | |||
| 55 | my ($self, $method) = @_; | |||
| 56 | ||||
| 57 | my $parent = $self->SUPER::can( $method ); | |||
| 58 | return $parent if $parent; | |||
| 59 | ||||
| 60 | my $package = ref( $self ) || $self; | |||
| 61 | my $filename = AutoLoader::find_filename( $package . '::' . $method ); | |||
| 62 | local $@; | |||
| 63 | return unless eval { require $filename }; | |||
| 64 | ||||
| 65 | 3 | 0.00050 | 0.00017 | no strict 'refs'; # spent 17µs making 1 call to strict::unimport |
| 66 | return \&{ $package . '::' . $method }; | |||
| 67 | } | |||
| 68 | ||||
| 69 | # spent 83µs within AutoLoader::find_filename which was called
# once (83µs+0) by AutoLoader::AUTOLOAD at line 23 | |||
| 70 | 12 | 7.8e-5 | 6.5e-6 | my $sub = shift; |
| 71 | my $filename; | |||
| 72 | # Braces used to preserve $1 et al. | |||
| 73 | { | |||
| 74 | # Try to find the autoloaded file from the package-qualified | |||
| 75 | # name of the sub. e.g., if the sub needed is | |||
| 76 | # Getopt::Long::GetOptions(), then $INC{Getopt/Long.pm} is | |||
| 77 | # something like '/usr/lib/perl5/Getopt/Long.pm', and the | |||
| 78 | # autoload file is '/usr/lib/perl5/auto/Getopt/Long/GetOptions.al'. | |||
| 79 | # | |||
| 80 | # However, if @INC is a relative path, this might not work. If, | |||
| 81 | # for example, @INC = ('lib'), then $INC{Getopt/Long.pm} is | |||
| 82 | # 'lib/Getopt/Long.pm', and we want to require | |||
| 83 | # 'auto/Getopt/Long/GetOptions.al' (without the leading 'lib'). | |||
| 84 | # In this case, we simple prepend the 'auto/' and let the | |||
| 85 | # C<require> take care of the searching for us. | |||
| 86 | ||||
| 87 | my ($pkg,$func) = ($sub =~ /(.*)::([^:]+)$/); | |||
| 88 | $pkg =~ s#::#/#g; | |||
| 89 | if (defined($filename = $INC{"$pkg.pm"})) { | |||
| 90 | if ($is_macos) { | |||
| 91 | $pkg =~ tr#/#:#; | |||
| 92 | $filename = undef | |||
| 93 | unless $filename =~ s#^(.*)$pkg\.pm\z#$1auto:$pkg:$func.al#s; | |||
| 94 | } else { | |||
| 95 | $filename = undef | |||
| 96 | unless $filename =~ s#^(.*)$pkg\.pm\z#$1auto/$pkg/$func.al#s; | |||
| 97 | } | |||
| 98 | ||||
| 99 | # if the file exists, then make sure that it is a | |||
| 100 | # a fully anchored path (i.e either '/usr/lib/auto/foo/bar.al', | |||
| 101 | # or './lib/auto/foo/bar.al'. This avoids C<require> searching | |||
| 102 | # (and failing) to find the 'lib/auto/foo/bar.al' because it | |||
| 103 | # looked for 'lib/lib/auto/foo/bar.al', given @INC = ('lib'). | |||
| 104 | ||||
| 105 | if (defined $filename and -r $filename) { | |||
| 106 | unless ($filename =~ m|^/|s) { | |||
| 107 | if ($is_dosish) { | |||
| 108 | unless ($filename =~ m{^([a-z]:)?[\\/]}is) { | |||
| 109 | if ($^O ne 'NetWare') { | |||
| 110 | $filename = "./$filename"; | |||
| 111 | } else { | |||
| 112 | $filename = "$filename"; | |||
| 113 | } | |||
| 114 | } | |||
| 115 | } | |||
| 116 | elsif ($is_epoc) { | |||
| 117 | unless ($filename =~ m{^([a-z?]:)?[\\/]}is) { | |||
| 118 | $filename = "./$filename"; | |||
| 119 | } | |||
| 120 | } | |||
| 121 | elsif ($is_vms) { | |||
| 122 | # XXX todo by VMSmiths | |||
| 123 | $filename = "./$filename"; | |||
| 124 | } | |||
| 125 | elsif (!$is_macos) { | |||
| 126 | $filename = "./$filename"; | |||
| 127 | } | |||
| 128 | } | |||
| 129 | } | |||
| 130 | else { | |||
| 131 | $filename = undef; | |||
| 132 | } | |||
| 133 | } | |||
| 134 | unless (defined $filename) { | |||
| 135 | # let C<require> do the searching | |||
| 136 | $filename = "auto/$sub.al"; | |||
| 137 | $filename =~ s#::#/#g; | |||
| 138 | } | |||
| 139 | } | |||
| 140 | return $filename; | |||
| 141 | } | |||
| 142 | ||||
| 143 | # spent 1.27ms within AutoLoader::import which was called 6 times, avg 212µs/call:
# once (733µs+0) at line 9 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/POSIX.pm
# once (231µs+0) at line 22 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/Storable.pm
# once (146µs+0) at line 6 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/Compress/Zlib.pm
# once (109µs+0) at line 6 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/Compress/Raw/Zlib.pm
# once (29µs+0) by POSIX::SigAction::BEGIN at line 65 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/POSIX.pm
# once (21µs+0) at line 69 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/POSIX.pm | |||
| 144 | 70 | 0.00122 | 1.7e-5 | my $pkg = shift; |
| 145 | my $callpkg = caller; | |||
| 146 | ||||
| 147 | # | |||
| 148 | # Export symbols, but not by accident of inheritance. | |||
| 149 | # | |||
| 150 | ||||
| 151 | if ($pkg eq 'AutoLoader') { | |||
| 152 | if ( @_ and $_[0] =~ /^&?AUTOLOAD$/ ) { | |||
| 153 | 3 | 0.00028 | 9.4e-5 | no strict 'refs'; # spent 19µs making 1 call to strict::unimport |
| 154 | *{ $callpkg . '::AUTOLOAD' } = \&AUTOLOAD; | |||
| 155 | *{ $callpkg . '::can' } = \&can; | |||
| 156 | } | |||
| 157 | } | |||
| 158 | ||||
| 159 | # | |||
| 160 | # Try to find the autosplit index file. Eg., if the call package | |||
| 161 | # is POSIX, then $INC{POSIX.pm} is something like | |||
| 162 | # '/usr/local/lib/perl5/POSIX.pm', and the autosplit index file is in | |||
| 163 | # '/usr/local/lib/perl5/auto/POSIX/autosplit.ix', so we require that. | |||
| 164 | # | |||
| 165 | # However, if @INC is a relative path, this might not work. If, | |||
| 166 | # for example, @INC = ('lib'), then | |||
| 167 | # $INC{POSIX.pm} is 'lib/POSIX.pm', and we want to require | |||
| 168 | # 'auto/POSIX/autosplit.ix' (without the leading 'lib'). | |||
| 169 | # | |||
| 170 | ||||
| 171 | (my $calldir = $callpkg) =~ s#::#/#g; | |||
| 172 | my $path = $INC{$calldir . '.pm'}; | |||
| 173 | if (defined($path)) { | |||
| 174 | # Try absolute path name. | |||
| 175 | if ($is_macos) { | |||
| 176 | (my $malldir = $calldir) =~ tr#/#:#; | |||
| 177 | $path =~ s#^(.*)$malldir\.pm\z#$1auto:$malldir:autosplit.ix#s; | |||
| 178 | } else { | |||
| 179 | $path =~ s#^(.*)$calldir\.pm\z#$1auto/$calldir/autosplit.ix#; | |||
| 180 | } | |||
| 181 | ||||
| 182 | eval { require $path; }; | |||
| 183 | # If that failed, try relative path with normal @INC searching. | |||
| 184 | if ($@) { | |||
| 185 | $path ="auto/$calldir/autosplit.ix"; | |||
| 186 | eval { require $path; }; | |||
| 187 | } | |||
| 188 | if ($@) { | |||
| 189 | my $error = $@; | |||
| 190 | require Carp; | |||
| 191 | Carp::carp($error); | |||
| 192 | } | |||
| 193 | } | |||
| 194 | } | |||
| 195 | ||||
| 196 | sub unimport { | |||
| 197 | my $callpkg = caller; | |||
| 198 | ||||
| 199 | 3 | 0.00011 | 3.8e-5 | no strict 'refs'; # spent 19µs making 1 call to strict::unimport |
| 200 | ||||
| 201 | for my $exported (qw( AUTOLOAD can )) { | |||
| 202 | my $symname = $callpkg . '::' . $exported; | |||
| 203 | undef *{ $symname } if \&{ $symname } == \&{ $exported }; | |||
| 204 | *{ $symname } = \&{ $symname }; | |||
| 205 | } | |||
| 206 | } | |||
| 207 | ||||
| 208 | 1 | 4.0e-6 | 4.0e-6 | 1; |
| 209 | ||||
| 210 | __END__ | |||
| 211 | ||||
| 212 | =head1 NAME | |||
| 213 | ||||
| 214 | AutoLoader - load subroutines only on demand | |||
| 215 | ||||
| 216 | =head1 SYNOPSIS | |||
| 217 | ||||
| 218 | package Foo; | |||
| 219 | use AutoLoader 'AUTOLOAD'; # import the default AUTOLOAD subroutine | |||
| 220 | ||||
| 221 | package Bar; | |||
| 222 | use AutoLoader; # don't import AUTOLOAD, define our own | |||
| 223 | sub AUTOLOAD { | |||
| 224 | ... | |||
| 225 | $AutoLoader::AUTOLOAD = "..."; | |||
| 226 | goto &AutoLoader::AUTOLOAD; | |||
| 227 | } | |||
| 228 | ||||
| 229 | =head1 DESCRIPTION | |||
| 230 | ||||
| 231 | The B<AutoLoader> module works with the B<AutoSplit> module and the | |||
| 232 | C<__END__> token to defer the loading of some subroutines until they are | |||
| 233 | used rather than loading them all at once. | |||
| 234 | ||||
| 235 | To use B<AutoLoader>, the author of a module has to place the | |||
| 236 | definitions of subroutines to be autoloaded after an C<__END__> token. | |||
| 237 | (See L<perldata>.) The B<AutoSplit> module can then be run manually to | |||
| 238 | extract the definitions into individual files F<auto/funcname.al>. | |||
| 239 | ||||
| 240 | B<AutoLoader> implements an AUTOLOAD subroutine. When an undefined | |||
| 241 | subroutine in is called in a client module of B<AutoLoader>, | |||
| 242 | B<AutoLoader>'s AUTOLOAD subroutine attempts to locate the subroutine in a | |||
| 243 | file with a name related to the location of the file from which the | |||
| 244 | client module was read. As an example, if F<POSIX.pm> is located in | |||
| 245 | F</usr/local/lib/perl5/POSIX.pm>, B<AutoLoader> will look for perl | |||
| 246 | subroutines B<POSIX> in F</usr/local/lib/perl5/auto/POSIX/*.al>, where | |||
| 247 | the C<.al> file has the same name as the subroutine, sans package. If | |||
| 248 | such a file exists, AUTOLOAD will read and evaluate it, | |||
| 249 | thus (presumably) defining the needed subroutine. AUTOLOAD will then | |||
| 250 | C<goto> the newly defined subroutine. | |||
| 251 | ||||
| 252 | Once this process completes for a given function, it is defined, so | |||
| 253 | future calls to the subroutine will bypass the AUTOLOAD mechanism. | |||
| 254 | ||||
| 255 | =head2 Subroutine Stubs | |||
| 256 | ||||
| 257 | In order for object method lookup and/or prototype checking to operate | |||
| 258 | correctly even when methods have not yet been defined it is necessary to | |||
| 259 | "forward declare" each subroutine (as in C<sub NAME;>). See | |||
| 260 | L<perlsub/"SYNOPSIS">. Such forward declaration creates "subroutine | |||
| 261 | stubs", which are place holders with no code. | |||
| 262 | ||||
| 263 | The AutoSplit and B<AutoLoader> modules automate the creation of forward | |||
| 264 | declarations. The AutoSplit module creates an 'index' file containing | |||
| 265 | forward declarations of all the AutoSplit subroutines. When the | |||
| 266 | AutoLoader module is 'use'd it loads these declarations into its callers | |||
| 267 | package. | |||
| 268 | ||||
| 269 | Because of this mechanism it is important that B<AutoLoader> is always | |||
| 270 | C<use>d and not C<require>d. | |||
| 271 | ||||
| 272 | =head2 Using B<AutoLoader>'s AUTOLOAD Subroutine | |||
| 273 | ||||
| 274 | In order to use B<AutoLoader>'s AUTOLOAD subroutine you I<must> | |||
| 275 | explicitly import it: | |||
| 276 | ||||
| 277 | use AutoLoader 'AUTOLOAD'; | |||
| 278 | ||||
| 279 | =head2 Overriding B<AutoLoader>'s AUTOLOAD Subroutine | |||
| 280 | ||||
| 281 | Some modules, mainly extensions, provide their own AUTOLOAD subroutines. | |||
| 282 | They typically need to check for some special cases (such as constants) | |||
| 283 | and then fallback to B<AutoLoader>'s AUTOLOAD for the rest. | |||
| 284 | ||||
| 285 | Such modules should I<not> import B<AutoLoader>'s AUTOLOAD subroutine. | |||
| 286 | Instead, they should define their own AUTOLOAD subroutines along these | |||
| 287 | lines: | |||
| 288 | ||||
| 289 | use AutoLoader; | |||
| 290 | use Carp; | |||
| 291 | ||||
| 292 | sub AUTOLOAD { | |||
| 293 | my $sub = $AUTOLOAD; | |||
| 294 | (my $constname = $sub) =~ s/.*:://; | |||
| 295 | my $val = constant($constname, @_ ? $_[0] : 0); | |||
| 296 | if ($! != 0) { | |||
| 297 | if ($! =~ /Invalid/ || $!{EINVAL}) { | |||
| 298 | $AutoLoader::AUTOLOAD = $sub; | |||
| 299 | goto &AutoLoader::AUTOLOAD; | |||
| 300 | } | |||
| 301 | else { | |||
| 302 | croak "Your vendor has not defined constant $constname"; | |||
| 303 | } | |||
| 304 | } | |||
| 305 | *$sub = sub { $val }; # same as: eval "sub $sub { $val }"; | |||
| 306 | goto &$sub; | |||
| 307 | } | |||
| 308 | ||||
| 309 | If any module's own AUTOLOAD subroutine has no need to fallback to the | |||
| 310 | AutoLoader's AUTOLOAD subroutine (because it doesn't have any AutoSplit | |||
| 311 | subroutines), then that module should not use B<AutoLoader> at all. | |||
| 312 | ||||
| 313 | =head2 Package Lexicals | |||
| 314 | ||||
| 315 | Package lexicals declared with C<my> in the main block of a package | |||
| 316 | using B<AutoLoader> will not be visible to auto-loaded subroutines, due to | |||
| 317 | the fact that the given scope ends at the C<__END__> marker. A module | |||
| 318 | using such variables as package globals will not work properly under the | |||
| 319 | B<AutoLoader>. | |||
| 320 | ||||
| 321 | The C<vars> pragma (see L<perlmod/"vars">) may be used in such | |||
| 322 | situations as an alternative to explicitly qualifying all globals with | |||
| 323 | the package namespace. Variables pre-declared with this pragma will be | |||
| 324 | visible to any autoloaded routines (but will not be invisible outside | |||
| 325 | the package, unfortunately). | |||
| 326 | ||||
| 327 | =head2 Not Using AutoLoader | |||
| 328 | ||||
| 329 | You can stop using AutoLoader by simply | |||
| 330 | ||||
| 331 | no AutoLoader; | |||
| 332 | ||||
| 333 | =head2 B<AutoLoader> vs. B<SelfLoader> | |||
| 334 | ||||
| 335 | The B<AutoLoader> is similar in purpose to B<SelfLoader>: both delay the | |||
| 336 | loading of subroutines. | |||
| 337 | ||||
| 338 | B<SelfLoader> uses the C<__DATA__> marker rather than C<__END__>. | |||
| 339 | While this avoids the use of a hierarchy of disk files and the | |||
| 340 | associated open/close for each routine loaded, B<SelfLoader> suffers a | |||
| 341 | startup speed disadvantage in the one-time parsing of the lines after | |||
| 342 | C<__DATA__>, after which routines are cached. B<SelfLoader> can also | |||
| 343 | handle multiple packages in a file. | |||
| 344 | ||||
| 345 | B<AutoLoader> only reads code as it is requested, and in many cases | |||
| 346 | should be faster, but requires a mechanism like B<AutoSplit> be used to | |||
| 347 | create the individual files. L<ExtUtils::MakeMaker> will invoke | |||
| 348 | B<AutoSplit> automatically if B<AutoLoader> is used in a module source | |||
| 349 | file. | |||
| 350 | ||||
| 351 | =head1 CAVEATS | |||
| 352 | ||||
| 353 | AutoLoaders prior to Perl 5.002 had a slightly different interface. Any | |||
| 354 | old modules which use B<AutoLoader> should be changed to the new calling | |||
| 355 | style. Typically this just means changing a require to a use, adding | |||
| 356 | the explicit C<'AUTOLOAD'> import if needed, and removing B<AutoLoader> | |||
| 357 | from C<@ISA>. | |||
| 358 | ||||
| 359 | On systems with restrictions on file name length, the file corresponding | |||
| 360 | to a subroutine may have a shorter name that the routine itself. This | |||
| 361 | can lead to conflicting file names. The I<AutoSplit> package warns of | |||
| 362 | these potential conflicts when used to split a module. | |||
| 363 | ||||
| 364 | AutoLoader may fail to find the autosplit files (or even find the wrong | |||
| 365 | ones) in cases where C<@INC> contains relative paths, B<and> the program | |||
| 366 | does C<chdir>. | |||
| 367 | ||||
| 368 | =head1 SEE ALSO | |||
| 369 | ||||
| 370 | L<SelfLoader> - an autoloader that doesn't use external files. | |||
| 371 | ||||
| 372 | =cut |