Added note for ::CGI.escapeHTML performance issue

lib/axlsx/workbook/worksheet/cell.rb

@@ -444,6 +444,9 @@ def cast_value(v)
  v ? 1 : 0
  else
  @type = :string
+ v.to_s
+ # TODO find a better way to do this as it accounts for 30% of
+ # processing time in benchmarking...
  ::CGI.escapeHTML(v.to_s)
  end
  end

test/benchmark.rb

@@ -4,11 +4,10 @@
 require 'axlsx'
 require 'csv'
 require 'benchmark'
-
 row = []
 input = (32..126).to_a.pack('U*').chars.to_a
 20.times { row << input.shuffle.join}
-times = 2000
+times = 3000
 Benchmark.bmbm(30) do |x|
 
  x.report('axlsx_noautowidth') {

test/profile.rb

@@ -1,31 +1,22 @@
 #!/usr/bin/env ruby -s
-# -*- coding: utf-8 -*-
 
 # Usage:
 # > ruby test/profile.rb
-# > pprof.rb --gif /tmp/axlsx_noautowidth > /tmp/axlsx_noautowidth.gif
+# > pprof.rb --gif /tmp/axlsx > /tmp/axlsx.gif
 # > open /tmp/axlsx_noautowidth.gif
 
 $:.unshift "#{File.dirname(__FILE__)}/../lib"
 require 'axlsx'
-require 'csv'
-
-# require 'benchmark'
 require 'perftools'
 row = []
+# Taking worst case scenario of all string data
 input = (32..126).to_a.pack('U*').chars.to_a
 20.times { row << input.shuffle.join}
 times = 3000
 
-PerfTools::CpuProfiler.start("/tmp/axlsx_noautowidth") do
+PerfTools::CpuProfiler.start("/tmp/axlsx") do
  p = Axlsx::Package.new
- #p.use_autowidth = false
- #p.use_shared_strings = true
- wb = p.workbook
-
- #A Simple Workbook
-
- wb.add_worksheet do |sheet|
+ p.workbook.add_worksheet do |sheet|
  times.times do
  sheet << row
  end