File Coverage

blib/lib/Convert/Binary/C/Cached.pm

Criterion	Covered	Total	%
statement	172	197	87.3
branch	100	134	74.6
condition	26	36	72.2
subroutine	17	19	89.4
pod	7	7	100.0
total	322	393	81.9

################################################################################
#
# MODULE: Convert::Binary::C::Cached
#
################################################################################
#
# DESCRIPTION: Cached version of Convert::Binary::C module
#
################################################################################
#
# Copyright (c) 2002-2020 Marcus Holland-Moritz. All rights reserved.
# This program is free software; you can redistribute it and/or modify
# it under the same terms as Perl itself.
#
################################################################################

package Convert::Binary::C::Cached;

use strict;
use Convert::Binary::C;
use Carp;
use vars qw( @ISA $VERSION );

@ISA = qw(Convert::Binary::C);

$VERSION = '0.84';

sub new
{
  my $class = shift;
  my $self = $class->SUPER::new;

  $self->{cache}      = undef;
  $self->{parsed}     = 0;
  $self->{uses_cache} = 0;

  @_ % 2 and croak "Number of configuration arguments to new must be even";

  @_ and $self->configure(@_);

  return $self;
}

sub configure
{
  my $self = shift;

  if (@_ < 2 and not defined wantarray) {
    $^W and carp "Useless use of configure in void context";
    return;
  }

  if (@_ == 0) {
    my $cfg = $self->SUPER::configure;
    $cfg->{Cache} = $self->{cache};
    return $cfg;
  }
  elsif (@_ == 1 and $_[0] eq 'Cache') {
    return $self->{cache};
  }

  my @args;

  if (@_ == 1) {
    @args = @_;
  }
  elsif (@_ % 2 == 0) {
    while (@_) {
      my %arg = splice @_, 0, 2;
      if (exists $arg{Cache}) {
        if ($self->{parsed}) {
          croak 'Cache cannot be configured after parsing';
        }
        elsif (ref $arg{Cache}) {
          croak 'Cache must be a string value, not a reference';
        }
        else {
          if (defined $arg{Cache}) {
            my @missing;
            eval { require Data::Dumper };
            $@ and push @missing, 'Data::Dumper';
            eval { require IO::File };
            $@ and push @missing, 'IO::File';
            if (@missing) {
              $^W and carp "Cannot load ", join(' and ', @missing), ", disabling cache";
              undef $arg{Cache};
            }
          }
          $self->{cache} = $arg{Cache};
        }
      }
      else { push @args, %arg }
    }
  }

  my $opt = $self;

  if (@args) {
    $opt = eval { $self->SUPER::configure(@args) };
    $@ =~ s/\s+at.*?Cached\.pm.*//s, croak $@ if $@;
  }

  $opt;
}

sub clean
{
  my $self = shift;

  delete $self->{$_} for grep !/^(?:|cache|parsed|uses_cache)$/, keys %$self;

  $self->{parsed}     = 0;
  $self->{uses_cache} = 0;

  $self->SUPER::clean;
}

sub clone
{
  my $self = shift;

  unless (defined wantarray) {
    $^W and carp "Useless use of clone in void context";
    return;
  }

  my $clone = $self->SUPER::clone;

  for (keys %$self) {
    if ($_) {
      $clone->{$_} = ref $_ eq 'ARRAY' ? [@{$self->{$_}}] : $self->{$_};
    }
  }

  $clone;
}

sub parse_file
{
  my $self = shift;
  my($warn,$error) = $self->__parse('file', $_[0]);
  for my $w ( @$warn ) { carp $w }
  defined $error and croak $error;
  defined wantarray and return $self;
}

sub parse
{
  my $self = shift;
  my($warn,$error) = $self->__parse('code', $_[0]);
  for my $w ( @$warn ) { carp $w }
  defined $error and croak $error;
  defined wantarray and return $self;
}

sub dependencies
{
  my $self = shift;

  $self->{parsed} or croak "Call to dependencies without parse data";

  unless (defined wantarray) {
    $^W and carp "Useless use of dependencies in void context";
    return;
  }

  $self->{files} || $self->SUPER::dependencies;
}

sub __uses_cache
{
  my $self = shift;
  $self->{uses_cache};
}

sub __parse
{
  my $self = shift;

  if (defined $self->{cache}) {
    $self->{parsed} and croak "Cannot parse more than once for cached objects";

    $self->{$_[0]} = $_[1];

    if ($self->__can_use_cache) {
      my @WARN;
      {
        local $SIG{__WARN__} = sub { push @WARN, $_[0] };
        eval { $self->SUPER::parse_file($self->{cache}) };
      }
      unless ($@ or @WARN) {
        $self->{parsed}     = 1;
        $self->{uses_cache} = 1;
        return;
      }
      $self->clean;
    }
  }

  $self->{parsed} = 1;

  my(@warnings, $error);
  {
    local $SIG{__WARN__} = sub { push @warnings, $_[0] };

    if ($_[0] eq 'file') {
      eval { $self->SUPER::parse_file($_[1]) };
    }
    else {
      eval { $self->SUPER::parse($_[1]) };
    }
  }

  if ($@) {
    $error = $@;
    $error =~ s/\s+at.*?Cached\.pm.*//s;
  }
  else {
    defined $self->{cache} and $self->__save_cache;
  }

  for (@warnings) { s/\s+at.*?Cached\.pm.*//s }

  (\@warnings, $error);
}

sub __can_use_cache
{
  my $self = shift;
  my $fh = IO::File->new;

  unless (-e $self->{cache} and -s _) {
    $ENV{CBCC_DEBUG} and print STDERR "CBCC: cache file '$self->{cache}' doesn't exist or is empty\n";
    return 0;
  }

  unless ($fh->open($self->{cache})) {
    $^W and carp "Cannot open '$self->{cache}': $!";
    $ENV{CBCC_DEBUG} and print STDERR "CBCC: cannot open cache file '$self->{cache}'\n";
    return 0;
  }

  my @warnings;
  my @config = do {
    my $config;
    unless (defined($config = <$fh>)) {
      $ENV{CBCC_DEBUG} and print STDERR "CBCC: cannot read configuration\n";
      return 0;
    }
    unless ($config =~ /^#if\s+0/) {
      $ENV{CBCC_DEBUG} and print STDERR "CBCC: invalid configuration\n";
      return 0;
    }
    local $/ = $/.'#endif';
    chomp($config = <$fh>);
    $config =~ s/^\*//gms;
    local $SIG{__WARN__} = sub { push @warnings, $_[0] };
    eval $config;
  };

  # corrupt config
  if ($@ or @warnings or @config % 2) {
    $ENV{CBCC_DEBUG} and print STDERR "CBCC: broken configuration\n";
    return 0;
  }

  my %config = @config;

  my $what = exists $self->{code} ? 'code' : 'file';

  unless (exists $config{$what} and
          $config{$what} eq $self->{$what} and
          __reccmp($config{cfg}, $self->configure)) {
    if ($ENV{CBCC_DEBUG}) {
      print STDERR "CBCC: configuration has changed\n";
      print STDERR "CBCC: what='$what', \$config{$what}='$config{$what}' \$self->{$what}='$self->{$what}'\n";
      my $dump = Data::Dumper->Dump([$config{cfg}, $self->configure], ['config', 'self']);
      $dump =~ s/^/CBCC: /mg;
      print STDERR $dump;
    }
    return 0;
  }

  while (my($file, $spec) = each %{$config{files}}) {
    unless (-e $file) {
      $ENV{CBCC_DEBUG} and print STDERR "CBCC: file '$file' deleted\n";
      return 0;
    }
    my($size, $mtime, $ctime) = (stat(_))[7,9,10];
    unless ($spec->{size} == $size and
            $spec->{mtime} == $mtime and
            $spec->{ctime} == $ctime) {
      $ENV{CBCC_DEBUG} and print STDERR "CBCC: size/mtime/ctime of '$file' changed\n";
      return 0;
    }
  }

  $self->{files} = $config{files};

  $ENV{CBCC_DEBUG} and print STDERR "CBCC: '$self->{cache}' is usable\n";
  return 1;
}

sub __save_cache
{
  my $self = shift;
  my $fh = IO::File->new;

  $fh->open(">$self->{cache}") or croak "Cannot open '$self->{cache}': $!";

  my $what = exists $self->{code} ? 'code' : 'file';

  my $config = Data::Dumper->new([{ $what => $self->{$what},
                                    cfg   => $self->configure,
                                    files => scalar $self->SUPER::dependencies,
                                 }], ['*'])->Indent(1)->Dump;
  $config =~ s/[^(]*//;
  $config =~ s/^/*/gms;

  print $fh "#if 0\n", $config, "#endif\n\n",
            do { local $^W; $self->sourcify({ Context => 1 }) };
}

sub __reccmp
{
  my($ref, $val) = @_;

  !defined($ref) && !defined($val) and return 1;
  !defined($ref) || !defined($val) and return 0;

  ref $ref or return $ref eq $val;

  if (ref $ref eq 'ARRAY') {
    @$ref == @$val or return 0;
    for (0..$#$ref) {
      __reccmp($ref->[$_], $val->[$_]) or return 0;
    }
  }
  elsif (ref $ref eq 'HASH') {
    keys %$ref == keys %$val or return 0;
    for (keys %$ref) {
      __reccmp($ref->{$_}, $val->{$_}) or return 0;
    }
  }
  else { return 0 }

  return 1;
}

1;

__END__