From 1b86d90136efb98c7b331a84ca163587307a49af Mon Sep 17 00:00:00 2001 From: "yuuji.yaginuma" Date: Thu, 17 May 2018 17:32:27 +0900 Subject: Enable `Performance/UnfreezeString` cop MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In Ruby 2.3 or later, `String#+@` is available and `+@` is faster than `dup`. ```ruby # frozen_string_literal: true require "bundler/inline" gemfile(true) do source "https://rubygems.org" gem "benchmark-ips" end Benchmark.ips do |x| x.report('+@') { +"" } x.report('dup') { "".dup } x.compare! end ``` ``` $ ruby -v benchmark.rb ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-linux] Warming up -------------------------------------- +@ 282.289k i/100ms dup 187.638k i/100ms Calculating ------------------------------------- +@ 6.775M (± 3.6%) i/s - 33.875M in 5.006253s dup 3.320M (± 2.2%) i/s - 16.700M in 5.032125s Comparison: +@: 6775299.3 i/s dup: 3320400.7 i/s - 2.04x slower ``` --- .../active_record/connection_adapters/abstract/database_statements.rb | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb') diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb index 5b24a467ec..c10da813ec 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb @@ -379,7 +379,7 @@ module ActiveRecord build_fixture_sql(fixtures, table_name) end.compact - table_deletes = tables_to_delete.map { |table| "DELETE FROM #{quote_table_name table}".dup } + table_deletes = tables_to_delete.map { |table| +"DELETE FROM #{quote_table_name table}" } total_sql = Array.wrap(combine_multi_statements(table_deletes + fixture_inserts)) disable_referential_integrity do -- cgit v1.2.3