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author | bogdanvlviv <bogdanvlviv@gmail.com> | 2018-06-15 09:07:18 +0300 |
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committer | bogdanvlviv <bogdanvlviv@gmail.com> | 2018-08-14 19:53:12 +0300 |
commit | b71abb3bb8cd177d1d3fceec88f54b505d616887 (patch) | |
tree | edb47a67fd44ab9a6fad7a38239094f2146fdad9 /actionpack/lib/action_dispatch/http/cache.rb | |
parent | e765bff13484b3c834f0e9979550196898dc7cc9 (diff) | |
download | rails-b71abb3bb8cd177d1d3fceec88f54b505d616887.tar.gz rails-b71abb3bb8cd177d1d3fceec88f54b505d616887.tar.bz2 rails-b71abb3bb8cd177d1d3fceec88f54b505d616887.zip |
Refactor `Array#extract!`
Avoid allocating the second array by using `Array#reject!` instead of
`Enumerable#partition` in `Array#extract!`.
There are benchmarks in order to ensure that the changes speed up the method:
```
begin
require "bundler/inline"
rescue LoadError => e
$stderr.puts "Bundler version 1.10 or later is required. Please update
your Bundler"
raise e
end
class Array
def extract_v1!(&block)
unless block_given?
to_enum(:extract!) { size }
else
extracted_elements, other_elements = partition(&block)
replace(other_elements)
extracted_elements
end
end
def extract_v2!
return to_enum(:extract!) { size } unless block_given?
extracted_elements = []
reject! do |element|
extracted_elements << element if yield(element)
end
extracted_elements
end
end
gemfile(true) do
source "https://rubygems.org"
gem "benchmark-ips"
end
arrays_for_partition = Array.new(1000) { (0..10000).to_a }
arrays_for_extract_v1 = Array.new(1000) { (0..10000).to_a }
arrays_for_extract_v2 = Array.new(1000) { (0..10000).to_a }
Benchmark.ips do |x|
x.report("Array#partition") do
arrays_for_partition.each do |numbers|
odd_numbers, numbers = numbers.partition { |number| number.odd? }
numbers
end
end
x.report("Array#extract_v1!") do
arrays_for_extract_v1.each do |numbers|
odd_numbers = numbers.extract_v1! { |number| number.odd? }
numbers
end
end
x.report("Array#extract_v2!") do
arrays_for_extract_v2.each do |numbers|
odd_numbers = numbers.extract_v2! { |number| number.odd? }
numbers
end
end
x.compare!
end
```
The result of the benchmarks:
```
ruby -v
ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-linux]
```
```
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Using benchmark-ips 2.7.2
Using bundler 1.16.1
Warming up --------------------------------------
Array#partition 1.000 i/100ms
Array#extract_v1! 1.000 i/100ms
Array#extract_v2! 1.000 i/100ms
Calculating -------------------------------------
Array#partition 1.390 (± 0.0%) i/s - 7.000 in 5.044843s
Array#extract_v1! 2.781 (± 0.0%) i/s - 14.000 in 5.050589s
Array#extract_v2! 3.151 (± 0.0%) i/s - 16.000 in 5.080608s
Comparison:
Array#extract_v2!: 3.2 i/s
Array#extract_v1!: 2.8 i/s - 1.13x slower
Array#partition: 1.4 i/s - 2.27x slower
```
Avoid `unless`/`else` in favour of an early return.
The double-negative of that `else` can be confusing,
even though the code layout is nearly the same.
Also using of early return would improve `git diff`
if we needed to change this method.
Diffstat (limited to 'actionpack/lib/action_dispatch/http/cache.rb')
0 files changed, 0 insertions, 0 deletions