Add support for re2 if it's available

Author: Vicent Marti

lib/email_reply_parser.rb

@@ -127,7 +127,14 @@ def read(text)
 
   private
     EMPTY = "".freeze
-    SIG_REGEX = /(--|__|\w-$)|(^(\w+\s*){1,3} #{"Sent from my".reverse}$)/n
+    SIGNATURE = '(?m)(--|__|\w-$)|(^(\w+\s*){1,3} ym morf tneS$)'
+
+    begin
+      require 're2'
+      SIG_REGEX = RE2::Regexp.new(SIGNATURE)
+    rescue LoadError
+      SIG_REGEX = Regexp.new(SIGNATURE)
+    end
 
     ### Line-by-Line Parsing
 
@@ -139,7 +146,7 @@ def read(text)
     # Returns nothing.
     def scan_line(line)
       line.chomp!("\n")
-      line.lstrip! unless line =~ SIG_REGEX
+      line.lstrip! unless SIG_REGEX.match(line) 
 
       # We're looking for leading `>`'s to see if this line is part of a
       # quoted Fragment.
@@ -148,7 +155,7 @@ def scan_line(line)
       # Mark the current Fragment as a signature if the current line is empty
       # and the Fragment starts with a common signature indicator.
       if @fragment && line == EMPTY
-        if @fragment.lines.last =~ SIG_REGEX
+        if SIG_REGEX.match @fragment.lines.last
           @fragment.signature = true
           finish_fragment
         end

test/email_reply_parser_test.rb

@@ -156,6 +156,12 @@ def test_one_is_not_on
     assert_match /^On Oct 1, 2012/, reply.fragments[1].to_s
   end
 
+  def test_pathological_emails
+    t0 = Time.now
+    reply = email("pathological")
+    assert (Time.now - t0) < 1
+  end
+
   def email(name)
     body = IO.read EMAIL_FIXTURE_PATH.join("#{name}.txt").to_s
     EmailReplyParser.read body

test/emails/pathological.txt

@@ -0,0 +1,20 @@
+I think you're onto something. I will try to fix the problem as soon as I
+get back to a computer.
+On Dec 8, 2013 2:10 PM, "John Sullivan" <[email protected]> wrote:
+
+> I think your code is shortening the reference sequence you return to be
+> the same size as the query sequence, and we end up losing data. Here's some
+> debugging output from me putzing around...
+>
+> name: gi|253409428|ref|GQ227366.1| Influenza A virus (A/pika/Qinghai/BI/2007(H5N1)) segment 1 polymerase PB2 (PB2) gene, complete cds
+> score: 39.0
+>
+> organism.sequence: ATGGAGAGAATAAAGGAATTAAGAGATCTAATGTCACAGTCCCGCACTCGCGAGATACTAACAAAGACCACTGTGGACCATATGGCCATAATCAAGAAATACACATCAGGAAGACAAGAGAAGAACCCTGCTCTCAGAATGAAATGGATGATGGCAATGAAATATCCAATCACAGCGGACAAGAGAATAATAGAGATGATTCCTGAAAGGAATGAACAAGGACAGACACTCTGGAGCAAGACAAATGATGCTGGATCGGACAGGGTGATGGTGTCTCCCCTAGCTGTAACTTGGTGGAATAGGAATGGGCCGACGACAAGTACAGTTCATTATCCAAAGGTTTACAAAACATACTTTGAGAAGGTTGAAAGGTTAAAACATGGAACCTTCGGTCCCGTTCATTTCCGAAACCAAGTTAAAATACGCCGCCGAGTTGATACAAATCCTGGCCATGCAGATCTCAGTGCTAAAGAAGCACAAGATGTCATCATGGAGGTCGTTTTCCCAAATGAAGTGGGAGCTAGAATATTGACTTCAGAGTCACAGTTGACAATAACGAAAGAGAAAAAAGAAGAGCTCCAAGATTGTAAGATTGCTCCCTTAATGGTTGCATACATGTTGGAAAGGGAACTGGTCCGCAAAACCAGATTCCTACCAGTAGCAGGCGGAACAAGCAGTGTGTACATTGAGGTATTGCATTTGACTCAAGGAACCTGCTGGGCACAGATGTACACTCCAGGCGGAGAAGTAAGAAATGACGATGTTGACCAGAGTTTGATCATTGCTGCCAGAAACATTGTTAGGAGAGCAACGGTATCAGCGGATCCACTGGCATCACTGCTGGAGATGTGTCACAGCACACAAATTGGTGGGATAAGGATGGTGGACATCCTTAGGCAAACTCCAACTGAGGAACAAGCTGTGGATATATGCAAAGCAGCAATGGGTCTGAGGATTAGTTCATCCTTTAGCTTTGGAG
+>  GCTTCACTTTCAAAAGAACAAGTGGATCATCCGCCACGAAGGAAGAGGAAGTGCTTACAGGCAACCTCCAAACATTGAAAATAAGAGTACATGAGGGGTATGAGGAGTTCACAATGGTTGGGCAGAGGGCAACAGCTATCCTGAGGAAAGCAACTAGAAGGCTGATTCAGTTGATAGTAAGTGGAAGAAACGAACAATCAATCGCTGAGGCAATCATTGTAGCAATGGTGTTCTCACAGGAGGATCGCATGATAAAAGCAGTCCGAGGCGATCTGAATTTCGTAAACAGAGCAAACCAAAGATTAAACCCCATGCATCAACTCCTGAGACATTTTCAAAAGGACGCAAAAGTGCTATTTCAGAATTGGGGAACTGAGCCAATTGATAATGTCATGGGGATGATCGGAATATTACCTGACATGACTCCCAGCACAGAAACGTCACTGAGAGGAGTGAGAGTTAGTAAAATGGGAGTAGATGAGTATTCCAGCACTGAGAGAGTAGTTGTAAGCATTGACCGCTTCTTAAGGGTTCGAGACCAGCGGGGGAACGTACTCTTATCTCCCGAAGAGGTCAGCGAAACCCAGGGAACAGAGAAGTTGACAATAACATATTCATCATCAATGATGTGGGAAATCAACGGTCCTGAGTCAGTGCTTGTTAACACTTACCAATGGATCATTAGAAACTGGGAGACCGTGAAAATTCAGTGGTCTCAGGACCCCACGATGTTGTACAATAAGATGGAGTTTGAACCGTTCCAATCCTTGGTACCTAAAGCTGCCAGAGGTCAATACAGTGGATTTGTGAGAACATTATTCCAACAAATGCGTGACGTACTGGGGACATTTGATACTGTCCAGATAATAAAGCTGCTACCATTTGCAGCAGCCCCACCGAAGCAGAGCAGAATGCAGTTTTCTTCTCTAACTGTGAATGTGAGAGGCTCAGGAATGAGAATACTCATAAGGGGCAATTCCCCTGTGTTCAACTACAA
+>  TAAGGCAACCCAAAGACTTACCGTTCTTGGAAAGGACGCAGGTGCATTAACAGAGGATCCAGATGAGGGGACAGCCGGAGTGGAATCTGCAGTACTGAGGGGGTTCCTAATTCTAGGCAAGGAGGACAAAAGATATGGACCAGCATTGAGCATCAATGAACTGAGCAATCTTGCAAAAGGGGAGAAAGCTAATGTGCTGATAGGGCAAGGAGACGTGGTGTTGGTAATGAAACGGAAACGGGACTCTAGCATACTTACTGACAGCCAGACAGCGACCAAAAGAATTCGGATGGCCATCAATTAGTGTCGAATTGTTTAAAAACGACCTTGTTTCTACT
+> reference_alignment: ________________________________________________
+>
+> query: AGCGAAAGCAGGTCAAATATATTCAATATGGAGAGAATAAAAGAATTAAG
+>
+> query_alignment: GCGAAAGCAGGTCAAATATATTCAATATGGAGAGAATAAAAGAATTAAG
+>