deduplicate strings using String#-@ (uminus) in Ruby 2.5+

This is faster than relying on eval() for older Rubies.
https://bugs.ruby-lang.org/issues/13077
Ruby 2.5 is targetted for release in December 2017.

2 files changed, 8 insertions, 7 deletions

diff --git a/lib/dtas/source/av_ff_common.rb b/lib/dtas/source/av_ff_common.rb
index d89ea17..ae654ba 100644
--- a/lib/dtas/source/av_ff_common.rb
+++ b/lib/dtas/source/av_ff_common.rb
@@ -109,13 +109,17 @@ module DTAS::Source::AvFfCommon # :nodoc:
       f = $1.dup
       f =~ /^duration=([\d\.]+)\s*$/nm and @duration = $1.to_f
       # TODO: multi-line/multi-value/repeated tags
-      f.gsub!(/^TAG:([^=]+)=(.*)$/ni) { |_| @comments[$1.upcase.freeze] = $2 }
+      f.gsub!(/^TAG:([^=]+)=(.*)$/ni) { |_|
+        @comments[DTAS.dedupe_str($1.upcase)] = DTAS.dedupe_str($2)
+      }
     end
 
     # new avprobe
     s.scan(%r{^\[format\.tags\]\n(.*?)\n\n}m) do |_|
       f = $1.dup
-      f.gsub!(/^([^=]+)=(.*)$/ni) { |_| @comments[$1.upcase.freeze] = $2 }
+      f.gsub!(/^([^=]+)=(.*)$/ni) { |_|
+        @comments[DTAS.dedupe_str($1.upcase)] = DTAS.dedupe_str($2)
+      }
     end
     s.scan(%r{^\[format\]\n(.*?)\n\n}m) do |_|
       f = $1.dup
diff --git a/lib/dtas/source/sox.rb b/lib/dtas/source/sox.rb
index 7f55c5d..f702b41 100644
--- a/lib/dtas/source/sox.rb
+++ b/lib/dtas/source/sox.rb
@@ -52,19 +52,16 @@ class DTAS::Source::Sox # :nodoc:
 
       if out =~ /\nComments\s*:[ \t]*\n?(.*)\z/mn
         comments = dst['comments'] = {}
-        # we use eval "#{str.inspect}".freeze
-        # take advantage of the VM-wide dedupe in MRI (rb_fstring):
         key = nil
         $1.split(/\n/n).each do |line|
           if line.sub!(/^([^=]+)=/ni, '')
-            key = $1.upcase
-            key = eval "#{key.inspect}.freeze"
+            key = DTAS.dedupe_str($1.upcase)
           end
           (comments[key] ||= ''.b) << "#{line}\n" unless line.empty?
         end
         comments.each do |k,v|
           v.chomp!
-          comments[k] = eval "#{v.inspect}.freeze"
+          comments[k] = DTAS.dedupe_str(v)
         end
       end
       dst