File Coverage

blib/lib/Algorithm/BinarySearch/Vec.pm

Criterion	Covered	Total	%
statement	129	133	96.9
branch	39	52	75.0
condition	12	15	80.0
subroutine	22	24	91.6
pod	1	1	100.0
total	203	225	90.2

package Algorithm::BinarySearch::Vec;

use Exporter;
use Carp;
use AutoLoader;
use Config qw();
use strict;
use bytes;

our @ISA = qw(Exporter);
our $VERSION = '0.08';

our ($HAVE_XS);
eval {
  require XSLoader;
  $HAVE_XS = XSLoader::load('Algorithm::BinarySearch::Vec', $VERSION);
} or do {
  $HAVE_XS = 0;
};

# Preloaded methods go here.
#require Algorithm::BinarySearch::Vec::XS::Whatever;

# Autoload methods go after =cut, and are processed by the autosplit program.

##======================================================================
## Exports
##======================================================================

no warnings 'portable'; ##-- avoid "Bit vector size > 32 non-portable" errors for native quads
our $HAVE_QUAD     = ($Config::Config{use64bitint} ##-- avoid errors with xs U64TYPE but no perl-side 64bit ints (e.g. freebsd w/o -use64bitint perl config option)
		      &&
		      ($HAVE_XS ? Algorithm::BinarySearch::Vec::XS::HAVE_QUAD()     : $Config::Config{d_quad})
		     );
our $KEY_NOT_FOUND =   $HAVE_XS ? Algorithm::BinarySearch::Vec::XS::KEY_NOT_FOUND() : 0xffffffff;
#our $KEY_NOT_FOUND =  $HAVE_XS ? Algorithm::BinarySearch::Vec::XS::KEY_NOT_FOUND() : ($HAVE_QUAD ? 0xffffffffffffffff : 0xffffffff);

our (%EXPORT_TAGS, @EXPORT_OK, @EXPORT);
BEGIN {
  %EXPORT_TAGS =
    (
     api   => [qw( vbsearch  vbsearch_lb  vbsearch_ub),
	       qw(vabsearch vabsearch_lb vabsearch_ub),
	       qw(vvbsearch vvbsearch_lb vvbsearch_ub),
	       qw(vunion vintersect vsetdiff),
	      ],
     const => [qw($HAVE_QUAD $KEY_NOT_FOUND)],
     debug => [qw(vget vset vec2array)],
    );
  $EXPORT_TAGS{all}     = [map {@$_} @EXPORT_TAGS{qw(api const debug)}];
  $EXPORT_TAGS{default} = [map {@$_} @EXPORT_TAGS{qw(api const)}];
  @EXPORT_OK            = @{$EXPORT_TAGS{all}};
  @EXPORT               = @{$EXPORT_TAGS{default}};
}

##======================================================================
## Debug wrappers

##--------------------------------------------------------------
## $val = vget($vec,$i,$nbits)
sub _vget {
  return vec($_[0],$_[1],$_[2]);
}

##--------------------------------------------------------------
## undef = vset($vec,$i,$nbits,$val)
sub _vset {
  return vec($_[0],$_[1],$_[2])=$_[3];
}


##======================================================================
## API: Search: element-wise

##--------------------------------------------------------------
## $index = vbsearch($v,$key,$nbits)
## $index = vbsearch($v,$key,$nbits,$ilo,$ihi)
sub _vbsearch {
  my ($vr,$key,$nbits,$ilo,$ihi) = (\$_[0],@_[1..$#_]);
  $ilo = 0 if (!defined($ilo));
  $ihi = 8*length($$vr)/$nbits if (!defined($ihi));
  my ($imid);
  while ($ilo < $ihi) {
    $imid = ($ihi+$ilo) >> 1;
    if (vec($$vr,$imid,$nbits) < $key) {
      $ilo = $imid + 1;
    } else {
      $ihi = $imid;
    }
  }
  return ($ilo==$ihi) && vec($$vr,$ilo,$nbits)==$key ? $ilo : $KEY_NOT_FOUND;
}

##--------------------------------------------------------------
## $index = vbsearch_lb($v,$key,$nbits)
## $index = vbsearch_lb($v,$key,$nbits,$ilo,$ihi)
sub _vbsearch_lb {
  my ($vr,$key,$nbits,$ilo,$ihi) = (\$_[0],@_[1..$#_]);
  $ilo = 0 if (!defined($ilo));
  $ihi = 8*length($$vr)/$nbits if (!defined($ihi));
  my ($imin,$imax,$imid) = ($ilo,$ihi);
  while ($ihi-$ilo > 1) {
    $imid = ($ihi+$ilo) >> 1;
    if (vec($$vr,$imid,$nbits) < $key) {
      $ilo = $imid;
    } else {
      $ihi = $imid;
    }
  }
  return $ilo if (                vec($$vr,$ilo,$nbits)==$key);
  return $ihi if ($ihi < $imax && vec($$vr,$ihi,$nbits)==$key);
  return $ilo if ($ilo > $imin || vec($$vr,$ilo,$nbits) <$key);
  return $KEY_NOT_FOUND;
}

##--------------------------------------------------------------
## $index = vbsearch_ub($v,$key,$nbits)
## $index = vbsearch_ub($v,$key,$nbits,$ilo,$ihi)
sub _vbsearch_ub {
  my ($vr,$key,$nbits,$ilo,$ihi) = (\$_[0],@_[1..$#_]);
  $ilo = 0 if (!defined($ilo));
  $ihi = 8*length($$vr)/$nbits if (!defined($ihi));
  my ($imin,$imax,$imid) = ($ilo,$ihi);
  while ($ihi-$ilo > 1) {
    $imid = ($ihi+$ilo) >> 1;
    if (vec($$vr,$imid,$nbits) > $key) {
      $ihi = $imid;
    } else {
      $ilo = $imid;
    }
  }
  return $ihi if ($ihi < $imax && vec($$vr,$ihi,$nbits)==$key);
  return $ilo if (                vec($$vr,$ilo,$nbits)>=$key);
  return $ihi>=$imax ? $KEY_NOT_FOUND : $ihi;
}

##======================================================================
## API: Search: array-wise

##--------------------------------------------------------------
## \@indices = vabsearch($v,\@keys,$nbits)
## \@indices = vabsearch($v,\@keys,$nbits,$ilo,$ihi)
sub _vabsearch {
  return [map {vbsearch($_[0],$_,@_[2..$#_])} @{$_[1]}];
}


##--------------------------------------------------------------
## \@indices = vabsearch_lb($v,\@keys,$nbits)
## \@indices = vabsearch_lb($v,\@keys,$nbits,$ilo,$ihi)
sub _vabsearch_lb {
  return [map {vbsearch_lb($_[0],$_,@_[2..$#_])} @{$_[1]}];
}

##--------------------------------------------------------------
## \@indices = vabsearch_ub($v,\@keys,$nbits)
## \@indices = vabsearch_ub($v,\@keys,$nbits,$ilo,$ihi)
sub _vabsearch_ub {
  return [map {vbsearch_ub($_[0],$_,@_[2..$#_])} @{$_[1]}];
}

##======================================================================
## API: Search: vec-wise

## \@a = vec2array($vec,$nbits)
sub vec2array {
  return [map {vec($_[0],$_,$_[1])} (0..(length($_[0])*8/$_[1]-1))];
}

##--------------------------------------------------------------
## $indices = vvbsearch($v,$keys,$nbits)
## $indices = vvbsearch($v,$keys,$nbits,$ilo,$ihi)
sub _vvbsearch {
  return pack('N*', @{vabsearch($_[0],vec2array(@_[1,2]),@_[2..$#_])});
}

##--------------------------------------------------------------
## $indices = vvbsearch_lb($v,$keys,$nbits)
## $indices = vvbsearch_lb($v,$keys,$nbits,$ilo,$ihi)
sub _vvbsearch_lb {
  return pack('N*', @{vabsearch_lb($_[0],vec2array(@_[1,2]),@_[2..$#_])});
}

##--------------------------------------------------------------
## $indices = vvbsearch_ub($v,$keys,$nbits)
## $indices = vvbsearch_ub($v,$keys,$nbits,$ilo,$ihi)
sub _vvbsearch_ub {
  return pack('N*', @{vabsearch_ub($_[0],vec2array(@_[1,2]),@_[2..$#_])});
}

##======================================================================
## API: set operations

##--------------------------------------------------------------
## $vunion = vunion($av,$bv,$nbits)
sub _vunion {
  my ($avr,$bvr,$nbits) = (\$_[0],\$_[1],$_[2]);
  die(__PACKAGE__ , "::_vunion(): cannot handle nbits < 8, but you requested $nbits") if ($nbits < 8);
  my $na = length($$avr)*8/$nbits;
  my $nb = length($$bvr)*8/$nbits;
  my $cv = '';
  my ($ai,$bi,$ci, $aval,$bval);
  for ($ai=0,$bi=0,$ci=0; $ai < $na && $bi < $nb; ++$ci) {
    $aval = vec($$avr,$ai,$nbits);
    $bval = vec($$bvr,$bi,$nbits);
    if ($aval <= $bval) {
      vec($cv,$ci,$nbits) = $aval;
      ++$ai;
      ++$bi if ($aval == $bval);
    } else { ##-- $aval == $bval
      vec($cv,$ci,$nbits) = $bval;
      ++$bi;
    }
  }
  $cv .= substr($$avr, $ai*$nbits/8);
  $cv .= substr($$bvr, $bi*$nbits/8);
  return $cv;
}

##--------------------------------------------------------------
## $vintersect = vintersect($av,$bv,$nbits)
sub _vintersect {
  my ($avr,$bvr,$nbits) = (\$_[0],\$_[1],$_[2]);
  die(__PACKAGE__ , "::_vintersect(): cannot handle nbits < 8, but you requested $nbits") if ($nbits < 8);

  ##-- ensure smaller set is "a"
  ($$avr,$$bvr) = ($$bvr,$$avr) if (length($$bvr) < length($$avr));

  my $na = length($$avr)*8/$nbits;
  my $nb = length($$bvr)*8/$nbits;
  my $cv = '';
  my ($ai,$bi,$ci, $blo,$aval,$bval);
  for ($ai=0,$blo=0,$ci=0; $ai < $na; ++$ai) {
    $aval = vec($$avr,$ai,$nbits);
    $bi   = _vbsearch_ub($$bvr,$aval,$nbits,$blo,$nb);
    last if ($bi == $KEY_NOT_FOUND);
    vec($cv,$ci++,$nbits) = $aval if ($aval == vec($$bvr,$bi,$nbits));
    $blo = $bi;
  }
  return $cv;
}

##--------------------------------------------------------------
## $vsetdiff = vsetdiff($av,$bv,$nbits)
sub _vsetdiff {
  my ($avr,$bvr,$nbits) = (\$_[0],\$_[1],$_[2]);
  die(__PACKAGE__ , "::_vintersect(): cannot handle nbits < 8, but you requested $nbits") if ($nbits < 8);

  my $na = length($$avr)*8/$nbits;
  my $nb = length($$bvr)*8/$nbits;
  my $cv = '';
  my ($ai,$bi,$ci, $blo,$aval,$bval);
  for ($ai=0,$blo=0,$ci=0; $ai < $na; ++$ai) {
    $aval = vec($$avr,$ai,$nbits);
    $bi   = _vbsearch_ub($$bvr,$aval,$nbits,$blo,$nb);
    last if ($bi == $KEY_NOT_FOUND);
    vec($cv,$ci++,$nbits) = $aval if ($aval != vec($$bvr,$bi,$nbits));
    $blo = $bi;
  }
  $cv .= substr($$avr, $ai*$nbits/8);
  return $cv;
}


##======================================================================
## delegate: attempt to delegate to XS module
foreach my $func (map {@$_} @EXPORT_TAGS{qw(api debug)}) {
  no warnings 'redefine';
  if ($HAVE_XS && Algorithm::BinarySearch::Vec::XS->can($func)) {
    eval "\*$func = \\&Algorithm::BinarySearch::Vec::XS::$func;";
  } elsif (__PACKAGE__->can("_$func")) {
    eval "\*$func = \\&_$func;";
  }
}


1; ##-- be happy

__END__