1 # Copyright (C) 2007-2011 Martin A. Hansen.
3 # This program is free software; you can redistribute it and/or
4 # modify it under the terms of the GNU General Public License
5 # as published by the Free Software Foundation; either version 2
6 # of the License, or (at your option) any later version.
8 # This program is distributed in the hope that it will be useful,
9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 # GNU General Public License for more details.
13 # You should have received a copy of the GNU General Public License
14 # along with this program; if not, write to the Free Software
15 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 # http://www.gnu.org/copyleft/gpl.html
19 # >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
21 # This software is part of the Biopieces framework (www.biopieces.org).
23 # >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
25 # SAM format version v1.4-r962 - April 17, 2011
27 # http://samtools.sourceforge.net/SAM1.pdf
30 require 'maasha/filesys'
32 require 'maasha/cigar'
34 REGEX_HEADER = Regexp.new(/^@[A-Za-z][A-Za-z](\t[A-Za-z][A-Za-z0-9]:[ -~]+)+$/)
35 REGEX_COMMENT = Regexp.new(/^@CO\t.*/)
37 FLAG_MULTI = 0x1 # Template having multiple fragments in sequencing
38 FLAG_ALIGNED = 0x2 # Each fragment properly aligned according to the aligner
39 FLAG_UNMAPPED = 0x4 # Fragment unmapped
40 FLAG_NEXT_UNMAPPED = 0x8 # Next fragment in the template unmapped
41 FLAG_REVCOMP = 0x10 # SEQ being reverse complemented
42 FLAG_NEXT_REVCOMP = 0x20 # SEQ of the next fragment in the template being reversed
43 FLAG_FIRST = 0x40 # The first fragment in the template
44 FLAG_LAST = 0x80 # The last fragment in the template
45 FLAG_SECONDARY_ALIGNMENT = 0x100 # Secondary alignment
46 FLAG_QUALITY_FAIL = 0x200 # Not passing quality controls
47 FLAG_DUPLICATES = 0x400 # PCR or optical duplicate
49 # Error class for all exceptions to do with Genbank.
50 class SamError < StandardError; end
52 # Class to parse and write SAM files.
54 attr_accessor :io, :header
56 # Class method to convert a SAM entry
57 # to a Biopiece record.
62 bp[:Q_ID] = sam[:QNAME]
63 bp[:STRAND] = sam[:FLAG].revcomp? ? '-' : '+'
64 bp[:S_ID] = sam[:RNAME]
65 bp[:S_BEG] = sam[:POS]
66 bp[:MAPQ] = sam[:MAPQ]
67 bp[:CIGAR] = sam[:CIGAR]
69 unless sam[:RNEXT] == '*'
70 bp[:Q_ID2] = sam[:RNEXT]
71 bp[:S_BEG2] = sam[:PNEXT]
72 bp[:TLEN] = sam[:TLEN]
75 bp[:SEQ] = sam[:SEQ].seq
77 unless sam[:SEQ].qual.nil?
78 bp[:SCORES] = sam[:SEQ].convert_phred2illumina!.qual
81 if sam.has_key? :NM and sam[:NM].to_i > 0
82 bp[:ALIGN] = self.align_descriptors(sam)
88 # Create align descriptors according to the KISS format description:
89 # http://code.google.com/p/biopieces/wiki/KissFormat
90 def self.align_descriptors(sam)
95 sam[:CIGAR].each do |len, op|
97 (0 ... len).each_with_index do |i|
98 nt = sam[:SEQ].seq[offset + i]
100 align << [offset + i, "->#{nt}"]
110 sam[:MD].scan(/\d+|\^[A-Z]+|[A-Z]+/).each do |m|
111 if m =~ /\d+/ # Matches
113 elsif m[0] == '^' # Deletions
114 m[1 .. -1].each_char do |nt|
115 align << [offset, "#{nt}>-"]
122 nt2 = sam[:SEQ].seq[offset - deletions]
124 align << [offset, "#{nt}>#{nt2}"]
131 align.sort_by { |a| a.first }.map { |k, v| "#{k}:#{v}" }.join(",")
134 # Method to initialize a Sam object.
135 def initialize(io = nil)
143 @io.each_line do |line|
144 unless line[0] == '@'
145 entry = parse_alignment(line.chomp)
147 yield entry if block_given?
154 # Method to parse the header section of a SAM file.
155 # Each header line should match:
156 # /^@[A-Za-z][A-Za-z](\t[A-Za-z][A-Za-z0-9]:[ -~]+)+$/ or /^@CO\t.*/.
157 # Tags containing lowercase letters are reserved for end users.
159 @io.each_line do |line|
160 if line =~ /^@([A-Za-z][A-Za-z])/
166 when 'HD' then subparse_header(line)
167 when 'SQ' then subparse_sequence(line)
168 when 'RG' then subparse_read_group(line)
169 when 'PG' then subparse_program(line)
170 when 'CO' then subparse_comment(line)
172 raise SamError, "Unknown header tag: #{tag}"
180 return @header.empty? ? nil : @header
183 # Method to subparse header lines.
184 def subparse_header(line)
186 fields = line.split("\t")
188 if fields[1] =~ /^VN:([0-9]+\.[0-9]+)$/
191 raise SamError, "Bad version number: #{fields[1]}"
195 if fields[2] =~ /^SO:(unknown|unsorted|queryname|coordinate)$/
198 raise SamError, "Bad sort order: #{fields[2]}"
205 # Method to subparse sequence lines.
206 def subparse_sequence(line)
207 @header[:SQ] = Hash.new unless @header[:SQ].is_a? Hash
210 fields = line.split("\t")
212 if fields[1] =~ /^SN:([!-)+-<>-~][!-~]*)$/
215 raise SamError, "Bad sequence name: #{fields[1]}"
218 if fields[2] =~ /^LN:(\d+)$/
221 raise SamError, "Bad sequence length: #{fields[2]}"
224 (3 ... fields.size).each do |i|
225 if fields[i] =~ /^(AS|M5|SP|UR):([ -~]+)$/
228 raise SamError, "Bad sequence tag: #{fields[i]}"
232 @header[:SQ][:SN] = Hash.new unless @header[:SQ][:SN].is_a? Hash
234 if @header[:SQ][:SN].has_key? seq_name
235 raise SamError, "Non-unique sequence name: #{seq_name}"
237 @header[:SQ][:SN][seq_name] = hash
241 # Method to subparse read group lines.
242 def subparse_read_group(line)
243 @header[:RG] = Hash.new unless @header[:RG].is_a? Hash
246 fields = line.split("\t")
248 if fields[1] =~ /^ID:([ -~]+)$/
251 raise SamError, "Bad read group identifier: #{fields[1]}"
254 (2 ... fields.size).each do |i|
255 if fields[i] =~ /^(CN|DS|DT|FO|KS|LB|PG|PI|PL|PU|SM):([ -~]+)$/
258 raise SamError, "Bad read group tag: #{fields[i]}"
263 unless hash[:FO] =~ /^\*|[ACMGRSVTWYHKDBN]+$/
264 raise SamError, "Bad flow order: #{hash[:FO]}"
269 unless hash[:PL] =~ /^(CAPILLARY|LS454|ILLUMINA|SOLID|HELICOS|IONTORRENT|PACBIO)$/
270 raise SamError, "Bad platform: #{hash[:PL]}"
274 @header[:RG][:ID] = Hash.new unless @header[:RG][:ID].is_a? Hash
276 if @header[:RG][:ID].has_key? id
277 raise SamError, "Non-unique read group identifier: #{id}"
279 @header[:RG][:ID][id] = hash
283 # Method to subparse program lines.
284 def subparse_program(line)
285 @header[:PG] = Hash.new unless @header[:PG].is_a? Hash
288 fields = line.split("\t")
290 if fields[1] =~ /^ID:([ -~]+)$/
293 raise SamError, "Bad program record identifier: #{fields[1]}"
296 (2 ... fields.size).each do |i|
297 if fields[i] =~ /^(PN|CL|PP|VN):([ -~]+)$/
300 raise SamError, "Bad program record tag: #{fields[i]}"
304 @header[:PG][:ID] = Hash.new unless @header[:PG][:ID].is_a? Hash
306 if @header[:PG][:ID].has_key? id
307 raise SamError, "Non-unique program record identifier: #{id}"
309 @header[:PG][:ID][id] = hash
313 # Method to subparse comment lines.
314 def subparse_comment(line)
315 @header[:CO] = Array.new unless @header[:CO].is_a? Array
317 if line =~ /^@CO\t(.+)/
320 raise SamError, "Bad comment line: #{line}"
324 # Method to subparse alignment lines.
325 def parse_alignment(line)
326 fields = line.split("\t")
328 raise SamError, "Bad number of fields: #{fields.size} < 11" if fields.size < 11
331 flag = fields[1].to_i
334 mapq = fields[4].to_i
337 pnext = fields[7].to_i
338 tlen = fields[8].to_i
354 entry[:QNAME] = qname
355 entry[:FLAG] = Flag.new(flag)
356 entry[:RNAME] = rname
359 entry[:CIGAR] = Cigar.new(cigar)
360 entry[:RNEXT] = rnext
361 entry[:PNEXT] = pnext
363 entry[:SEQ] = (qual == '*') ? Seq.new(qname, seq) : Seq.new(qname, seq, qual)
366 # Optional fields - where some are really important! HATE HATE HATE SAM!!!
368 fields[11 .. -1].each do |field|
369 tag, type, val = field.split(':')
371 raise SamError, "Non-unique optional tag: #{tag}" if entry.has_key? tag.to_sym
373 # A [!-~] Printable character
375 # i [-+]?[0-9]+ Singed 32-bit integer
377 raise SamError, "Bad tag in optional field: #{field}" unless val =~ /^[-+]?[0-9]+$/
381 # f [-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)? Single-precision floating number
382 # Z [ !-~]+ Printable string, including space
383 # H [0-9A-F]+ Byte array in the Hex format
384 # B [cCsSiIf](,[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?)+ Integer or numeric array
386 entry[tag.to_sym] = val
392 # Method to check qname.
393 def check_qname(qname)
394 raise SamError, "Bad qname: #{qname}" unless qname =~ /^[!-?A-~]{1,255}$/
397 # Method to check flag.
399 raise SamError, "Bad flag: #{flag}" unless (0 .. 2**16 - 1).include? flag
402 # Method to check if rname, when not '*' and
403 # @SQ header lines are present, is located in
405 def check_rname(rname)
406 raise SamError, "Bad rname: #{rname}" unless rname =~ /^(\*|[!-()+-<>-~][!-~]*)$/
408 unless @header.empty? or rname == '*'
409 unless @header[:SQ][:SN].has_key? rname.to_sym
410 raise SamError, "rname not found in header hash: #{rname}"
415 # Method to check pos.
417 raise SamError, "Bad pos: #{pos}" unless (0 .. 2**29 - 1).include? pos
420 # Method to check mapq.
422 raise SamError, "Bad mapq: #{mapq}" unless (0 .. 2**8 - 1).include? mapq
425 # Method to check if rnext, when not '*' or '='
426 # and @SQ header lines are present, is located
427 # in the header hash.
428 def check_rnext(rnext)
429 raise SamError, "Bad rnext: #{rnext}" unless rnext =~ /^(\*|=|[!-()+-<>-~][!-~]*)$/
431 unless @header.empty? or rnext == '*' or rnext == '='
432 unless @header[:SQ][:SN].has_key? rnext.to_sym
433 raise SamError, "rnext not found in header hash: #{rnext}"
438 # Method to check pnext.
439 def check_pnext(pnext)
440 raise SamError, "Bad pnext: #{pnext}" unless (0 .. 2**29 - 1).include? pnext
443 # Method to check tlen.
445 raise SamError, "Bad tlen: #{tlen}" unless (-2**29 + 1 .. 2**29 - 1).include? tlen
448 # Method to check seq.
450 raise SamError, "Bad seq: #{seq}" unless seq =~ /^(\*|[A-Za-z=.]+)$/
453 # Method to check qual.
455 raise SamError, "Bad qual: #{qual}" unless qual =~ /^[!-~]+$/
458 # Method to deconvolute the SAM flag field.
462 # Method to initialize a Flag object.
467 # Method to test if template have
468 # multiple fragments in sequencing.
473 # Method to test if each fragment
474 # properly aligned according to the aligner.
479 # Method to test if the fragment was unmapped.
484 # Method to test if the next fragment was unmapped.
486 flag & FLAG_NEXT_UNMAPPED
489 # Method to test if the fragment was reverse complemented.
494 # Method to test if the next fragment was reverse complemented.
496 flag & FLAG_NEXT_REVCOMP
499 # Method to test if the fragment was first in the template.
504 # Method to test if the fragment was last in the template.
509 # Method to test for secondary alignment.
510 def secondary_alignment?
511 flag & FLAG_SECONDARY_ALIGNMENT
514 # Method to test for quality fail.
516 flag & FLAG_QUALITY_FAIL
519 # Method to test for PCR or optical duplicates.
521 flag & FLAG_DUPLICATES
527 # >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<