lib/Bio/SeqFeature/Collection.pm

   1 #
   2 # BioPerl module for Bio::SeqFeature::Collection
   3 #
   4 # Please direct questions and support issues to <bioperl-l@bioperl.org>
   5 #
   6 # Cared for by Jason Stajich <jason@bioperl.org>
   7 #
   8 # Copyright Jason Stajich
   9 #
  10 # You may distribute this module under the same terms as perl itself
  11
  12 # POD documentation - main docs before the code
  13
  14 =head1 NAME
  15
  16 Bio::SeqFeature::Collection - A container class for SeqFeatures
  17 suitable for performing operations such as finding features within a
  18 range, that match a certain feature type, etc.
  19
  20 =head1 SYNOPSIS
  21
  22   use Bio::SeqFeature::Collection;
  23   use Bio::Location::Simple;
  24   use Bio::Tools::GFF;
  25   use Bio::Root::IO;
  26   use File::Spec;
  27   # let's first input some features
  28   my $gffio = Bio::Tools::GFF->new(-file => File::Spec->catfile
  29                                  ("t","data","myco_sites.gff"),
  30                                  -gff_version => 2);
  31   my @features = ();
  32   # loop over the input stream
  33   while(my $feature = $gffio->next_feature()) {
  34       # do something with feature
  35       push @features, $feature;
  36   }
  37   $gffio->close();
  38   # build the Collection object
  39   my $col = Bio::SeqFeature::Collection->new();
  40   # add these features to the object
  41   my $totaladded = $col->add_features(\@features);
  42
  43   my @subset = $col->features_in_range(-start => 1,
  44                                      -end => 25000,
  45                                      -strand => 1,
  46                                      -contain => 0);
  47   # subset should have 18 entries for this dataset
  48   print "size is ", scalar @subset, "\n";
  49   @subset = $col->features_in_range(-range => Bio::Location::Simple->new
  50                                   (-start => 70000,
  51                                    -end => 150000,
  52                                    -strand => -1),
  53                                   -contain => 1,
  54                                   -strandmatch => 'strong');
  55
  56   # subset should have 22 entries for this dataset
  57   print "size is ", scalar @subset, "\n";
  58   print "total number of features in collection is ",
  59          $col->feature_count(),"\n";
  60
  61 =head1 DESCRIPTION
  62
  63 This object will efficiently allow one for query subsets of ranges
  64 within a large collection of sequence features (in fact the objects
  65 just have to be Bio::RangeI compliant).  This is done by the creation
  66 of bins which are stored in order in a B-Tree data structure as
  67 provided by the DB_File interface to the Berkeley DB.
  68
  69 This is based on work done by Lincoln for storage in a mysql instance
  70 - this is intended to be an embedded in-memory implementation for
  71 easily querying for subsets of a large range set.
  72
  73 Collections can be made persistent by keeping the indexfile and
  74 passing in the -keep flag like this:
  75
  76   my $collection = Bio::SeqFeature::Collection->new(-keep => 1,
  77                                                    -file => 'col.idx');
  78   $collaction->add_features(\@features);
  79   undef $collection;
  80
  81   # To reuse this collection, next time you initialize a Collection object
  82   # specify the filename and the index will be reused.
  83   $collection = Bio::SeqFeature::Collection->new(-keep => 1,
  84                                                 -file => 'col.idx');
  85
  86
  87
  88 =head1 FEEDBACK
  89
  90 =head2 Mailing Lists
  91
  92 User feedback is an integral part of the evolution of this and other
  93 Bioperl modules. Send your comments and suggestions preferably to
  94 the Bioperl mailing list.  Your participation is much appreciated.
  95
  96   bioperl-l@bioperl.org                  - General discussion
  97   http://bioperl.org/wiki/Mailing_lists  - About the mailing lists
  98
  99 =head2 Support
 100
 101 Please direct usage questions or support issues to the mailing list:
 102
 103 I<bioperl-l@bioperl.org>
 104
 105 rather than to the module maintainer directly. Many experienced and
 106 reponsive experts will be able look at the problem and quickly
 107 address it. Please include a thorough description of the problem
 108 with code and data examples if at all possible.
 109
 110 =head2 Reporting Bugs
 111
 112 Report bugs to the Bioperl bug tracking system to help us keep track
 113 of the bugs and their resolution. Bug reports can be submitted via
 114 the web:
 115
 116   https://github.com/bioperl/bioperl-live/issues
 117
 118 =head1 AUTHOR - Jason Stajich
 119
 120 Email jason@bioperl.org
 121
 122 =head1 CONTRIBUTORS
 123
 124 Using code and strategy developed by Lincoln Stein (lstein@cshl.org)
 125 in Bio::DB::GFF implementation.  Credit also to Lincoln for suggesting
 126 using Storable to serialize features rather than my previous implementation
 127 which kept the features in memory.
 128
 129 =head1 APPENDIX
 130
 131 The rest of the documentation details each of the object methods.
 132 Internal methods are usually preceded with a _
 133
 134 =cut
 135
 136
 137 # Let the code begin...
 138
 139
 140 package Bio::SeqFeature::Collection;
 141 use strict;
 142
 143 # Object preamble - inherits from Bio::Root::Root
 144
 145 use Bio::DB::GFF::Util::Binning;
 146 use DB_File;
 147 use Bio::Location::Simple;
 148 use Bio::SeqFeature::Generic;
 149 use Storable qw(freeze thaw);
 150
 151 use base qw(Bio::Root::Root Bio::SeqFeature::CollectionI);
 152
 153
 154 # This may need to get re-optimized for BDB usage as these
 155 # numbers were derived empirically by Lincoln on a mysql srv
 156 # running on his laptop
 157
 158 # this is the largest that any reference sequence can be (100 megabases)
 159 use constant MAX_BIN    => 100_000_000;
 160
 161 # this is the smallest bin (1 K)
 162 use constant MIN_BIN    => 1_000;
 163
 164 =head2 new
 165
 166  Title   : new
 167  Usage   : my $obj = Bio::SeqFeature::Collection->new();
 168  Function: Builds a new Bio::SeqFeature::Collection object
 169  Returns : Bio::SeqFeature::Collection
 170  Args    :
 171
 172            -minbin        minimum value to use for binning
 173                           (default is 100,000,000)
 174            -maxbin        maximum value to use for binning
 175                           (default is 1,000)
 176            -file          filename to store/read the
 177                           BTREE from rather than an in-memory structure
 178                           (default is false and in-memory).
 179            -keep          boolean, will not remove index file on
 180                           object destruction.
 181            -features      Array ref of features to add initially
 182
 183 =cut
 184
 185 sub new {
 186   my($class,@args) = @_;
 187
 188   my $self = $class->SUPER::new(@args);
 189   my ($maxbin,$minbin, $file, $keep,
 190       $features) = $self->_rearrange([qw(MAXBIN MINBIN FILE KEEP
 191                                          FEATURES)],@args);
 192
 193   defined $maxbin && $self->max_bin($maxbin);
 194   defined $minbin && $self->min_bin($minbin);
 195
 196   defined $features &&  $self->add_features($features);
 197   $DB_BTREE->{'flags'} = R_DUP ;
 198   $DB_BTREE->{'compare'} = \&_compare;
 199   $self->{'_btreehash'} = {};
 200   if( $file ) {
 201       $self->debug("using file $file");
 202       $self->indexfile($file);
 203   }
 204   $self->keep($keep);
 205   $self->{'_btree'} = tie %{$self->{'_btreehash'}},
 206   'DB_File', $self->indexfile, O_RDWR|O_CREAT, 0640, $DB_BTREE;
 207   $self->{'_btree'} || $self->throw("Unable to tie DB_File handle");
 208   return $self;
 209 }
 210
 211
 212 =head2 add_features
 213
 214  Title   : add_features
 215  Usage   : $collection->add_features(\@features);
 216  Function:
 217  Returns : number of features added
 218  Args    : arrayref of Bio::SeqFeatureI objects to index
 219
 220
 221 =cut
 222
 223 sub add_features{
 224    my ($self,$feats) = @_;
 225    if( ref($feats) !~ /ARRAY/i ) {
 226        $self->warn("Must provide a valid Array reference to add_features");
 227        return 0;
 228    }
 229    my $count = 0;
 230    foreach my $f ( @$feats ) {
 231        if( ! $f || ! ref($f) || ! $f->isa('Bio::RangeI') ) {
 232            $self->warn("Must provide valid Bio::RangeI objects to add_features, skipping object '$f'\n");
 233            next;
 234        }
 235        my $bin = bin($f->start,$f->end,$self->min_bin);
 236        my $serialized = &feature_freeze($f);
 237        $self->{'_btree'}->put($bin,$serialized);
 238        if( $f->isa('Bio::SeqFeature::Generic') ) {
 239            $self->debug( "$bin for ". $f->location->to_FTstring(). " matches ".$#{$self->{'_features'}}. "\n");
 240        }
 241        $count++;
 242    }
 243    return $count;
 244 }
 245
 246
 247 =head2 features_in_range
 248
 249  Title   : features_in_range
 250  Usage   : my @features = $collection->features_in_range($range)
 251  Function: Retrieves a list of features which were contained or overlap the
 252            the requested range (see Args for way to specify overlap or
 253                                 only those containe)d
 254  Returns : List of Bio::SeqFeatureI objects
 255  Args    : -range => Bio::RangeI object defining range to search,
 256            OR
 257            -start  => start,
 258            -end    => end,
 259            -strand  => strand
 260
 261            -contain => boolean - true if feature must be completely
 262                        contained with range
 263                        OR false if should include features that simply overlap
 264                        the range. Default: true.
 265            -strandmatch =>  'strong',  ranges must have the same strand
 266                             'weak',    ranges must have the same
 267                                            strand or no strand
 268                             'ignore', ignore strand information
 269                            Default. 'ignore'.
 270
 271 =cut
 272
 273 sub features_in_range{
 274    my $self = shift;
 275    my (@args) = @_;
 276    my ($range, $contain, $strandmatch,$start,$end,$strand);
 277    if( @args == 1 ) {
 278        $range = shift @args;
 279    } else {
 280        ($start,$end,$strand,$range,
 281         $contain,$strandmatch) = $self->_rearrange([qw(START END
 282                                                        STRAND
 283                                                        RANGE CONTAIN
 284                                                        STRANDMATCH)],
 285                                                    @args);
 286        $contain = 1 unless defined $contain;
 287    }
 288    $strand = 1 unless defined $strand;
 289    if( $strand !~ /^([\-\+])$/ &&
 290        $strand !~ /^[\-\+]?1$/ ) {
 291        $self->warn("must provide a valid numeric or +/- for strand");
 292        return ();
 293    }
 294    if( defined $1 ) { $strand .= 1; }
 295
 296    if( !defined $start && !defined $end ) {
 297        if( ! defined $range || !ref($range) || ! $range->isa("Bio::RangeI") )
 298        {
 299            $self->warn("Must defined a valid Range for the method feature_in_range");
 300            return ();
 301        }
 302        ($start,$end,$strand) = ($range->start,$range->end,$range->strand);
 303    }
 304    my $r = Bio::Location::Simple->new(-start => $start,
 305                                      -end   => $end,
 306                                      -strand => $strand);
 307
 308    my @features;
 309    my $maxbin = $self->max_bin;
 310    my $minbin = $self->min_bin;
 311    my $tier = $maxbin;
 312    my ($k,$v,@bins) = ("",undef);
 313    while ($tier >= $minbin) {
 314         my ($tier_start,$tier_stop) = (bin_bot($tier,$start),
 315                                        bin_top($tier,$end));
 316        if( $tier_start == $tier_stop ) {
 317            my @vals = $self->{'_btree'}->get_dup($tier_start);
 318            if( scalar @vals > 0 ) {
 319                push @bins, map { thaw($_) } @vals;
 320            }
 321        } else {
 322            $k = $tier_start;
 323            my @vals;
 324            for( my $rc = $self->{'_btree'}->seq($k,$v,R_CURSOR);
 325                 $rc == 0;
 326                 $rc = $self->{'_btree'}->seq($k,$v, R_NEXT) ) {
 327                last if( $k > $tier_stop || $k < $tier_start);
 328                push @bins, thaw($v);
 329            }
 330        }
 331        $tier /= 10;
 332    }
 333    my %seen = ();
 334    foreach my $t ( map { ref($_) } @bins) {
 335        next if $seen{$t}++;
 336        eval "require $t";
 337
 338        if( $@ ) {
 339            $self->warn("Trying to thaw a stored feature $t which does not appear in your Perl library. $@");
 340            next;
 341        }
 342    }
 343    $strandmatch = 'ignore' unless defined $strandmatch;
 344    return ( $contain ) ? grep { $r->contains($_,$strandmatch) } @bins :
 345        grep { $r->overlaps($_,$strandmatch)} @bins;
 346 }
 347
 348 =head2 remove_features
 349
 350  Title   : remove_features
 351  Usage   : $collection->remove_features(\@array)
 352  Function: Removes the requested sequence features (based on features
 353            which have the same location)
 354  Returns : Number of features removed
 355  Args    : Arrayref of Bio::RangeI objects
 356
 357
 358 =cut
 359
 360 sub remove_features{
 361    my ($self,$feats) = @_;
 362    if( ref($feats) !~ /ARRAY/i ) {
 363        $self->warn("Must provide a valid Array reference to remove_features");
 364        return 0;
 365    }
 366    my $countprocessed = 0;
 367
 368    foreach my $f ( @$feats ) {
 369        next if ! ref($f) || ! $f->isa('Bio::RangeI');
 370        my $bin = bin($f->start,$f->end,$self->min_bin);
 371        my @vals = $self->{'_btree'}->get_dup($bin);
 372        my $vcount = scalar @vals;
 373
 374        foreach my $v ( @vals )  {
 375            # Once we have uniquely identifiable field
 376            # I think it will work better.
 377            if( $v eq &feature_freeze($f) ) {
 378                $self->{'_btree'}->del_dup($bin,$v);
 379                $vcount--;
 380                $countprocessed++;
 381            }
 382        }
 383        if( $vcount == 0 ) {
 384            $self->{'_btree'}->del($bin);
 385        }
 386    }
 387    $countprocessed;
 388
 389 }
 390
 391 =head2 get_all_features
 392
 393  Title   : get_all_features
 394  Usage   : my @f = $col->get_all_features()
 395  Function: Return all the features stored in this collection (Could be large)
 396  Returns : Array of Bio::RangeI objects
 397  Args    : None
 398
 399
 400 =cut
 401
 402 sub get_all_features{
 403    my ($self) = @_;
 404    my @features;
 405    my ($key,$value);
 406    for (my $status = $self->{'_btree'}->seq($key, $value, R_FIRST) ;
 407         $status == 0 ;
 408         $status = $self->{'_btree'}->seq($key, $value, R_NEXT) )
 409    {   next unless defined $value;
 410        push @features, &thaw($value);
 411    }
 412    if( scalar @features !=  $self->feature_count() ) {
 413        $self->warn("feature count does not match actual count\n");
 414    }
 415    return @features;
 416 }
 417
 418
 419 =head2 min_bin
 420
 421  Title   : min_bin
 422  Usage   : my $minbin= $self->min_bin;
 423  Function: Get/Set the minimum value to use for binning
 424  Returns : integer
 425  Args    : [optional] minimum bin value
 426
 427
 428 =cut
 429
 430 sub min_bin {
 431   my ($self,$min) = @_;
 432   if( defined $min ) {
 433       $self->{'_min_bin'} = $min;
 434   }
 435   return $self->{'_min_bin'}  || MIN_BIN;
 436 }
 437
 438 =head2 max_bin
 439
 440  Title   : max_bin
 441  Usage   : my $maxbin= $self->max_bin;
 442  Function: Get/Set the maximum value to use for binning
 443  Returns : integer
 444  Args    : [optional] maximum bin value
 445
 446
 447 =cut
 448
 449 sub max_bin {
 450   my ($self,$max) = @_;
 451   if( defined $max ) {
 452       $self->{'_max_bin'} = $max;
 453   }
 454   return $self->{'max_bin'} || MAX_BIN;
 455 }
 456
 457 =head2 feature_count
 458
 459  Title   : feature_count
 460  Usage   : my $c = $col->feature_count()
 461  Function: Retrieve the total number of features in the collection
 462  Returns : integer
 463  Args    : none
 464
 465
 466 =cut
 467
 468 sub feature_count {
 469     my $self = shift;
 470     my $count = 0;
 471     for ( keys %{$self->{'_btreehash'}} ) {
 472         my $v = $self->{'_btreehash'}->{$_};
 473         next unless defined  $v;
 474         $count++;
 475     }
 476     $count;
 477 }
 478
 479 =head2 indexfile
 480
 481  Title   : indexfile
 482  Usage   : $obj->indexfile($newval)
 483  Function: Get/set the filename where index is kept
 484  Returns : value of indexfile (a filename string)
 485  Args    : on set, new value (a filename string )
 486
 487
 488 =cut
 489
 490 sub indexfile{
 491     my $self = shift;
 492
 493     return $self->{'indexfile'} = shift if @_;
 494     return $self->{'indexfile'};
 495 }
 496
 497 =head2 keep
 498
 499  Title   : keep
 500  Usage   : $obj->keep($newval)
 501  Function: Get/set boolean flag to keep the indexfile after
 502            exiting program
 503  Example :
 504  Returns : value of keep (boolean)
 505  Args    : on set, new value (boolean)
 506
 507
 508 =cut
 509
 510 sub keep{
 511     my $self = shift;
 512
 513     return $self->{'keep'} = shift if @_;
 514     return $self->{'keep'};
 515 }
 516
 517 sub _compare{
 518     if( defined $_[0] && ! defined $_[1]) {
 519         return -1;
 520     } elsif ( defined $_[1] && ! defined $_[0]) {
 521         return 1;
 522     }
 523     $_[0] <=> $_[1];
 524 }
 525
 526 sub feature_freeze {
 527     my $obj = shift;
 528     _remove_cleanup_methods($obj);
 529     return freeze($obj);
 530 }
 531
 532 sub _remove_cleanup_methods {
 533     my $obj = shift;
 534
 535     # we have to remove any cleanup methods here for Storable
 536     for my $funcref ( $obj->_cleanup_methods ) {
 537         $obj->_unregister_for_cleanup($funcref);
 538     }
 539
 540     # ... and the same for any contained features; hopefully any implementations
 541     # adhere to implementing Bio::SeqFeatureI::sub_SeqFeature
 542
 543     for my $contained ($obj->sub_SeqFeature) {
 544         _remove_cleanup_methods($contained);
 545     }
 546
 547     1;
 548 }
 549
 550 sub feature_thaw {
 551     return thaw(shift);
 552 }
 553
 554 sub DESTROY {
 555     my $self = shift;
 556     $self->{'_btree'} = undef;
 557     untie(%{$self->{'_btreehash'}});
 558     if( ! $self->keep && $self->indexfile ) {
 559         my $f = $self->indexfile;
 560         $self->debug( "unlinking ".$f. "\n");
 561         close($f);
 562         unlink($f);
 563     }
 564     $self->SUPER::DESTROY();
 565 }
 566
 567 1;