From: "Glenn M. Lewis" <noSpam@...>
Date: 2005-09-09T12:46:30+09:00
Subject: Optimizing a single slow method

Hi!
	I have a Ruby script (a small part of it is included below)
that has many methods, but one method is so incredibly slow that
I would like to write it in C++ (or any other faster language).

	The method is "Contract.parseFile(file)".  I've tried the
latest SWIG, but am having a heck of a time trying to call the
two methods: "Contract.open()" and "Contract.addTick()" from within
the SWIG'd extension.  (By the way, I also tried "rio(file).csv {|fields|"
but that had the same speed as the code below.)

	Any ideas on how I can rewrite 'Contract.parseFile()' for
speed?

	Thanks!
-- Glenn Lewis

class Contract
   @@contracts = Hash.new
   @@files = Hash.new
   DataDir = "c:/src/Data"
   MonthNames = %w(nil jan feb mar apr may jun jul aug sep oct nov dec)
   def Contract.open(contract)
     @@contracts.has_key?(contract) ? @@contracts[contract] : Contract.new(contract)
   end
   def Contract.all
     @@contract.keys
   end
   def Contract.parseFile(file)
     return unless File.exists?(file)
     return if @@files.has_key?(file)
     @@files[file] = 1
     print "Parsing file #{file}..."
     File.open(file, "rb").each_line {|line|
       line.chomp!
       # puts line
       fields = line.split(/,/)
       next if fields.size < 8
       datestring = fields[1]
       year  = datestring[0..1].to_i
       month = datestring[2..3].to_i
       day   = datestring[4..5].to_i
       # puts "year=#{year}, month=#{month}, day=#{day}"
       # RUBY BUG?!?  Can't use 'date' here... as that messes up findTick's 'date'...
       mydate  = Date.new((year < 50 ? year+2000 : year+1900), month, day)
       contract = Contract.open(fields[0])
       tick = Tick.new(mydate, fields[2].to_f, fields[3].to_f,
		      fields[4].to_f, fields[5].to_f,
		      fields[6].to_i, fields[7].to_i)
       contract.addTick(tick)
     }
     puts "done"
   end
   def initialize(contract)
     @contract = contract
     @@contracts[contract] = self
     @ticks = Hash.new
   end
   def addTick(tick)
     @ticks[tick.date.to_s[0..9]] = tick
   end
end