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| author | Sean Griffin <sean@seantheprogrammer.com> | 2016-09-26 10:27:11 -0400 |
|---|---|---|
| committer | Sean Griffin <sean@seantheprogrammer.com> | 2016-09-26 10:27:11 -0400 |
| commit | a6da7938017647dd6e19e23d3d47126cb7a3e1fe (patch) | |
| tree | e46c6fd36d800143321b486565ebba79a3bb1f5a | |
| parent | 15a8740d68ccf1f376b5f2cf29c5336d8716278f (diff) | |
| download | rails-a6da7938017647dd6e19e23d3d47126cb7a3e1fe.tar.gz rails-a6da7938017647dd6e19e23d3d47126cb7a3e1fe.tar.bz2 rails-a6da7938017647dd6e19e23d3d47126cb7a3e1fe.zip | |
Use xor to avoid allocations in `AR::Core#hash`
This is not as good a solution as actually hashing both values, but Ruby
doesn't expose that capability other than allocating the array. Unless we were
to do something silly like have a thread local array that is re-used, I don't
see any other way to do this without allocation. This solution may not be
perfect, but it should reasonably avoid collisions to the extent that we need.
| -rw-r--r-- | activerecord/lib/active_record/core.rb | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb index 3465b68ac6..622df0cfc1 100644 --- a/activerecord/lib/active_record/core.rb +++ b/activerecord/lib/active_record/core.rb @@ -452,7 +452,7 @@ module ActiveRecord # [ Person.find(1), Person.find(2), Person.find(3) ] & [ Person.find(1), Person.find(4) ] # => [ Person.find(1) ] def hash if id - [self.class, id].hash + self.class.hash ^ self.id.hash else super end |