On Feb 20, 2008, at 15:12 , MenTaLguY wrote:
of iterations = 1000000
user system total realnull_time 0.218000 0.000000 0.218000 ( 0.219000)
split/each/<<+ 24.516000 0.140000 24.656000 ( 24.703000)
split/map/<<+ 26.109000 0.172000 26.281000 ( 26.281000)
split/inject/<<+ 30.797000 0.172000 30.969000 ( 31.000000)Being an FP nut used to using folds, I’m always a little annoyed that
inject fares so poorly in these things; mainly we’re just lacking a
C implementation of Array#inject.
coming back to this point… what do you mean by we’re missing a C
impl of Array#inject? Granted, the impl is on Enumerable, but I
wouldn’t think it would make THAT much of a difference… But I try my
best not to speculate (ever), so…
(my C coding skills absolutely suck these days, please point out
improvements)
#!/usr/bin/env ruby -w
require ‘benchmark’
require ‘ipaddr’
$: << File.expand_path("~/Work/p4/zss/src/RubyInline/dev/lib")
require ‘inline’
class Array
inline do |builder|
builder.c_raw <<-EOF
VALUE new_inject(int argc, VALUE *argv, VALUE self) {
long max = RARRAY(self)->len;
long i = argc ? 0 : 1;
VALUE memo = argc ? argv[0] : RARRAY(self)->ptr[0];
for (i; i < max; i++) {
memo = rb_yield_values(2, memo, RARRAY(self)->ptr[i]);
}
return memo;
}
EOF
end
end
p “127.0.0.1”.split(’.’).inject(0) { |s,n| (s << 8) + n.to_i }
p “127.0.0.1”.split(’.’).new_inject(0) { |s,n| (s << 8) + n.to_i }
max = (ARGV.shift || 1_000_000).to_i
# of iterations = 1000000
user system total real
null_time 0.130000 0.000000 0.130000 ( 0.129965)
split/each/<< 10.940000 0.010000 10.950000 ( 10.968329)
split/inject/<< 15.280000 0.020000 15.300000 ( 15.330062)
split/new_inject/<< 15.020000 0.070000 15.090000 ( 15.629343)
puts “# of iterations = #{max}”
Benchmark::bm(22) do |x|
x.report(“null_time”) do
for i in 0…max do
# do nothing
end
end
x.report(“split/each/<<”) do
for i in 0…max do
ip = 0
“127.0.0.1”.split(’.’).each { |n| ip = (ip << 8) + n.to_i }
ip
end
end
x.report(“split/inject/<<”) do
for i in 0…max do
“127.0.0.1”.split(’.’).inject(0) { |s,n| (s << 8) + n.to_i }
end
end
x.report(“split/new_inject/<<”) do
for i in 0…max do
“127.0.0.1”.split(’.’).new_inject(0) { |s,n| (s << 8) + n.to_i }
end
end
end