From e81b0ddd7ac9fe6de0ec65a2aa59224108344470 Mon Sep 17 00:00:00 2001 From: schneems Date: Wed, 29 Aug 2018 11:36:07 -0500 Subject: Faster time_value.rb MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The multiplication of the value takes a long time when we can instead mutate and use the string value directly. The `microsec` perf increases speed by 27% in the ideal case (which is the most common). ``` original_string = ".443959" require 'benchmark/ips' Benchmark.ips do |x| x.report("multiply") { string = original_string.dup (string.to_r * 1_000_000).to_i } x.report("new ") { string = original_string.dup if string && string.start_with?(".".freeze) && string.length == 7 string[0] = ''.freeze string.to_i end } x.compare! end # Warming up -------------------------------------- # multiply 125.783k i/100ms # new 146.543k i/100ms # Calculating ------------------------------------- # multiply 1.751M (± 3.3%) i/s - 8.805M in 5.033779s # new 2.225M (± 2.1%) i/s - 11.137M in 5.007110s # Comparison: # new : 2225289.7 i/s # multiply: 1751254.2 i/s - 1.27x slower ``` --- activemodel/lib/active_model/type/helpers/time_value.rb | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'activemodel/lib/active_model') diff --git a/activemodel/lib/active_model/type/helpers/time_value.rb b/activemodel/lib/active_model/type/helpers/time_value.rb index cb6aa67a9d..da56073436 100644 --- a/activemodel/lib/active_model/type/helpers/time_value.rb +++ b/activemodel/lib/active_model/type/helpers/time_value.rb @@ -70,7 +70,13 @@ module ActiveModel # Doesn't handle time zones. def fast_string_to_time(string) if string =~ ISO_DATETIME - microsec = ($7.to_r * 1_000_000).to_i + microsec_part = $7 + if microsec_part && microsec_part.start_with?(".") && microsec_part.length == 7 + microsec_part[0] = "" + microsec = microsec_part.to_i + else + microsec = (microsec_part.to_r * 1_000_000).to_i + end new_time $1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, microsec end end -- cgit v1.2.3