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author | Ryuta Kamizono <kamipo@gmail.com> | 2019-06-14 21:24:54 +0900 |
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committer | Ryuta Kamizono <kamipo@gmail.com> | 2019-06-15 21:48:12 +0900 |
commit | 85b4ba2836437ff30ff565005b2500500200611b (patch) | |
tree | b42b9621f32ebd951f25787e9f76b441872d9fdd /actionpack/lib/action_dispatch/journey/path | |
parent | c8a84603e2fa97822407bf4a1c8ac0308a899163 (diff) | |
download | rails-85b4ba2836437ff30ff565005b2500500200611b.tar.gz rails-85b4ba2836437ff30ff565005b2500500200611b.tar.bz2 rails-85b4ba2836437ff30ff565005b2500500200611b.zip |
No allocation `Arel::Visitors::ToSql#visit`
Each `visit o, collector` allocates one extra array due to
receiving args by splat array.
https://github.com/rails/rails/blob/2c3332cc4c0fa77dbe2e13e8a792f80fbd8f4ad3/activerecord/lib/arel/visitors/visitor.rb#L27-L29
Currently 1,000 times `User.where(id: 1).to_sql` allocates 13,000
arrays in `visitor.accept`. This avoids receiving args by splat array,
it makes `visitor.accept` no array allocation.
```ruby
ObjectSpace::AllocationTracer.setup(%i{path line type})
pp ObjectSpace::AllocationTracer.trace {
1_000.times { User.where(id: 1).to_sql }
}.select { |k, _| k[2] == :T_ARRAY && k[0].end_with?("visitor.rb", "to_sql.rb") }
```
Before (2c3332cc4c0fa77dbe2e13e8a792f80fbd8f4ad3):
```
{["~/rails/activerecord/lib/arel/visitors/to_sql.rb",
18,
:T_ARRAY]=>[1000, 0, 0, 0, 0, 0],
["~/rails/activerecord/lib/active_record/connection_adapters/determine_if_preparable_visitor.rb",
11,
:T_ARRAY]=>[1000, 0, 0, 0, 0, 0],
["~/rails/activerecord/lib/arel/visitors/visitor.rb",
12,
:T_ARRAY]=>[1000, 0, 0, 0, 0, 0],
["~/rails/activerecord/lib/arel/visitors/to_sql.rb",
788,
:T_ARRAY]=>[3000, 0, 0, 0, 0, 0],
["~/rails/activerecord/lib/arel/visitors/to_sql.rb",
794,
:T_ARRAY]=>[3000, 0, 0, 0, 0, 0],
["~/rails/activerecord/lib/arel/visitors/to_sql.rb",
156,
:T_ARRAY]=>[1000, 0, 0, 0, 0, 0],
["~/rails/activerecord/lib/arel/visitors/to_sql.rb",
443,
:T_ARRAY]=>[1000, 0, 0, 0, 0, 0],
["~/rails/activerecord/lib/arel/visitors/to_sql.rb",
603,
:T_ARRAY]=>[1000, 0, 0, 0, 0, 0],
["~/rails/activerecord/lib/arel/visitors/to_sql.rb",
611,
:T_ARRAY]=>[1000, 0, 0, 0, 0, 0]}
```
After (this change):
```
{}
```
Diffstat (limited to 'actionpack/lib/action_dispatch/journey/path')
0 files changed, 0 insertions, 0 deletions