plist_lite

plist_lite is the fastest plist processor for Ruby written in C.

It converts Ruby objects to an XML plist (a.k.a. property list), and vice versa.

plist_lite provides 2 APIs:

• PlistLite#dump(object)
• PlistLite#load(plist_string)

require 'plist_lite'
plist = PlistLite.dump({foo: 'bar', ary: [1,2,3], time: Time.at(0)})
# => "<?xml version=\"1.0\" encoding=\"UTF-8\"?><!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\"><plist version=\"1.0\"><dict><key>foo</key><string>bar</string><key>ary</key><array><integer>1</integer><integer>2</integer><integer>3</integer></array><key>time</key><date>1970-01-01T00:00:00Z</date></dict></plist>"
PlistLite.load(plist)
# => {"foo"=>"bar", "ary"=>[1, 2, 3], "time"=>1970-01-01 00:00:00 UTC}

• Avoid using Date because it does not have time zone information like Time or DateTime.

There is another competitor called plist.

Here are differences between plist_lite and plist:

1. plist_lite is 5 times faster than plist, see benchmark.

2. plist_lite knows how to handle encoding while plist doesn't.

   plist assume all strings are UTF-8 encoded.

   ruby -rplist -e 'puts Plist::Emit.dump("兜".encode(Encoding::BIG5))'

   <?xml version="1.0" encoding="UTF-8"?>
   <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
   <plist version="1.0">
   <string></string>
   </plist>
   

3. plist_lite treat binary string as binary data while plist treats IO and StringIO instances as binary data. The design of plist makes little sense.

4. plist uses Marshal#dump to handle unsupported data types that makes it vulnerable.

5. plist_lite knows how to handle XML encoding while plist doesn't.

   According the the spec, escaping " and ' is unnecessary.

   ruby -rplist -e 'puts Plist::Emit.dump "\""'

   <?xml version="1.0" encoding="UTF-8"?>
   <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
   <plist version="1.0">
   <string>&quot;</string>
   </plist>
   

ruby -Ilib benchmark/dump.rb

Rehearsal ----------------------------------------------------
Plist::Emit.dump   3.715427   0.003159   3.718586 (  3.720294)
PlistLite.dump     0.634391   0.000851   0.635242 (  0.635718)
------------------------------------------- total: 4.353828sec

                       user     system      total        real
Plist::Emit.dump   3.853843   0.003882   3.857725 (  3.860390)
PlistLite.dump     0.700628   0.001118   0.701746 (  0.702823)

ruby -Ilib benchmark/load.rb

Rehearsal ---------------------------------------------------
Plist.parse_xml   2.220934   1.423194   3.644128 (  3.645330)
PlistLite.load    0.598344   0.007032   0.605376 (  0.605603)
------------------------------------------ total: 4.249504sec

                      user     system      total        real
Plist.parse_xml   2.265274   1.454423   3.719697 (  3.721122)
PlistLite.load    0.673733   0.005373   0.679106 (  0.679638)