If it will not use special variables (like $1, $&, $`...),
it can improve the performance by using Regexp#match? or String#match? instead of Regexp#=~ or String#=~.
This patch is same idea as https://github.com/ruby/ruby/pull/1836
[Fix GH-1842]
## Environment
* OS : Ubuntu 17.10
* Compiler : gcc version 7.2.0
* CPU : Intel(R) Core(TM) i5-3210M CPU @ 2.50GHz
* Memory : 16 GB
## TL;DR
Methods | Before | After | Speed up
----------- | ------ | ------ | --------
CSV.foreach | 44.825 | 48.201 | 7.5%
CSV#shift | 45.200 | 49.584 | 9.7%
CSV.read | 42.968 | 46.853 | 9.0%
CSV.table | 10.933 | 11.277 | 3.1%
## Before
```
Calculating -------------------------------------
CSV.foreach 44.825 (± 0.0%) i/s - 228.000 in 5.086576s
CSV#shift 45.200 (± 0.0%) i/s - 228.000 in 5.044297s
CSV.read 42.968 (± 0.0%) i/s - 216.000 in 5.027504s
CSV.table 10.933 (± 0.0%) i/s - 55.000 in 5.031098s
```
## After
```
Calculating -------------------------------------
CSV.foreach 48.201 (± 0.0%) i/s - 244.000 in 5.062256s
CSV#shift 49.584 (± 0.0%) i/s - 248.000 in 5.001652s
CSV.read 46.853 (± 0.0%) i/s - 236.000 in 5.037044s
CSV.table 11.277 (± 0.0%) i/s - 57.000 in 5.054694s
```
## Benchmark code
```ruby
require 'csv'
require 'benchmark/ips'
CSV.open("/tmp/file.csv", "w") do |csv|
csv << ["player", "gameA", "gameB"]
1000.times do
csv << ['"Alice"', "84.0", "79.5"]
csv << ['"Bob"', "20.0", "56.5"]
end
end
Benchmark.ips do |x|
x.report "CSV.foreach" do
CSV.foreach("/tmp/file.csv") do |row|
end
end
x.report "CSV#shift" do
CSV.open("/tmp/file.csv") do |csv|
while line = csv.shift
end
end
end
x.report "CSV.read" do
CSV.read("/tmp/file.csv")
end
x.report "CSV.table" do
CSV.table("/tmp/file.csv")
end
end
```
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62806 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/csv.rb (CSV::Table#to_a, #to_csv): use Array#push instead of
Array#concat for performance improvement. This performance improvement is
proposed by zdennis <zach.dennis@gmail.com>. The patch is from
Mau Magnaguagno <maumagnaguagno@gmail.com>.
close#946
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59657 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
It ignored all of lines when given Regexp special characters.
[Feature #9147][ruby-core:58549]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59639 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/csv.rb: fix incompatibility introduced in r59428.
CSV.new takes options as keyword arguments.
* test/csv/test_features.rb: add a test to ensure it raises error againt
unknown options
* test/csv/test_features.rb: add a test to ensure row_sep option is properly
applied
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59437 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/csv.rb: usb keyword parameters to receive options
* test/csv/test_features.rb: remove a test for checking options
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59428 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Use character class directly instead of
character class in character class.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58827 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/csv.rb (CSV#shift): the last column is an Array in extended
column since r55985. [ruby-dev:49964] [Bug #13149]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57406 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
if no block is given. [ruby-core:75346] [Feature #11058]
* test/csv/test_row.rb: add test for above.
* test/csv/test_table.rb: ditto.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56083 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/csv.rb (CSV#shift): store partial quoted strings in an array
and join at last, to improve performance with very long quoted
lines. [ruby-core:76987] [Bug #12691]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55985 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/csv.rb: encoding must be plased at the first line except for
shebang. [fix GH-1116]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52850 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
patch is from Andrew Vit. [ruby-core:63215] [Feature #9952]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47663 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/csv.rb (CSV#<<): honor explicity given encoding. based on
the patch by DAISUKE TANIWAKI <daisuketaniwaki AT gmail.com> at
[ruby-core:62113]. [Bug #9766]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46391 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
CSV to miss escaping some special meaning characters when used
in parsing.
Reported by David Unric
[ruby-core:54986] [Bug #8405]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45374 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
to prevent the alternative, which is that each line in the CSV gets
converted to a Regexp when calling skip_lines#match.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43823 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/csv.rb (CSV.foreach): support enumerator. based on a patch by
Hanmac (Hans Mackowiak) at [ruby-core:57643]. [ruby-core:57283]
[Feature #8929]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43135 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* lib/csv.rb (CSV#<<): use StringIO#set_encoding instead of creating
new StringIO instance with String#force_encoding, forcing encoding
discards the cached coderange bits and can make further operations
very slow. [ruby-core:55714] [Bug #8585]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41722 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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