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@lsylvester
Forked from thedarkone/gist:599605
Created September 28, 2010 04:01
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## Original
def orig_reverse_sql_order(order_query)
order_query.join(', ').split(',').collect { |s|
if s.match(/\s(asc|ASC)$/)
s.gsub(/\s(asc|ASC)$/, ' DESC')
elsif s.match(/\s(desc|DESC)$/)
s.gsub(/\s(desc|DESC)$/, ' ASC')
else
s + ' DESC'
end
}
end
## Modified
def mod1_reverse_sql_order(order_query)
order_query.join(', ').split(',').collect { |s|
if s.match(/\s(asc|ASC)$/)
s.gsub!(/\s(asc|ASC)$/, ' DESC')
elsif s.match(/\s(desc|DESC)$/)
s.gsub!(/\s(desc|DESC)$/, ' ASC')
else
s.concat(' DESC')
end
s
}
end
## Modified - don't create match object
def mod2_reverse_sql_order(order_query)
order_query.join(', ').split(',').collect { |s|
if s =~ /\s(asc|ASC)$/
s.gsub!(/\s(asc|ASC)$/, ' DESC')
elsif s =~ /\s(desc|DESC)$/
s.gsub!(/\s(desc|DESC)$/, ' ASC')
else
s.concat(' DESC')
end
s
}
end
## Modified - case?
def mod3_reverse_sql_order(order_query)
order_query.join(', ').split(',').collect { |s|
case s
when /\s(asc|ASC)$/
s.gsub!(/\s(asc|ASC)$/, ' DESC')
when /\s(desc|DESC)$/
s.gsub!(/\s(desc|DESC)$/, ' ASC')
else
s.concat(' DESC')
end
s
}
end
## Lazy gsub?
def lazy_reverse_sql_order(order_query)
order_query.join(', ').split(',').collect do |s|
s.gsub!(/\sasc\Z/i, ' DESC') || s.gsub!(/\sdesc\Z/i, ' ASC') || s.concat(' DESC')
end
end
order_query = ['created_at ASC, updated_at desc, id']
require 'benchmark'
include Benchmark
bm do |x|
x.report('orig:'){ 100000.times { orig_reverse_sql_order(order_query)} }
x.report('mod1:'){ 100000.times { mod1_reverse_sql_order(order_query)} }
x.report('mod2:'){ 100000.times { mod2_reverse_sql_order(order_query)} }
x.report('mod3:'){ 100000.times { mod3_reverse_sql_order(order_query)} }
x.report('lazy:'){ 100000.times { lazy_reverse_sql_order(order_query)} }
end
__END__
user system total real
orig: 1.660000 0.040000 1.700000 ( 1.689658)
mod1: 1.650000 0.030000 1.680000 ( 1.693604)
mod2: 1.370000 0.030000 1.400000 ( 1.395524)
mod3: 1.340000 0.020000 1.360000 ( 1.358895)
lazy: 0.930000 0.030000 0.960000 ( 0.954206)
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