When requesting columns names from database adapters AR:Result
would dup/freeze column names, this prefers using fstrings which
cuts down on repeat allocations
Attributes that are retained keep these fstrings around for the long
term
Note, this has the highest impact on "short" result sets, eg: Topic.first where you can void allocating the number of columns * String.
`QueryAttribute#value_for_database` calls only `type.serialize`, and
`Boolean#serialize` is a no-op unlike other attribute types.
It caused the issue #32624. Whether or not `serialize` will invoke
`cast` is undefined in our test cases, but it actually does not work
properly unless it does so for now.
Fixes#32624.
Since `parse_raw_value_as_a_number` may not always parse raw value from
database as a number without type casting (e.g. "$150.55" as money
format).
Fixes#32531.
Since #26074, introduced force equality checking to build a predicate
consistently for both `find` and `create` (fixes#27313).
But the assumption that only array/range attribute have subtype was
wrong. We need to make force equality checking more strictly not to
allow serialized attribute.
Fixes#32761.
When an array of hashes is added to a `HashWithIndifferentAccess`, the
hashes are replaced with HWIAs by mutating the array in place.
If an attribute's value is an array of hashes, `changes_to_save` will
convert it to an array of HWIAs as a side-effect of adding it to the
changes hash.
Using `merge!` instead of `[]=` fixes the problem, as `merge!` copies
any array values in the provided hash instead of mutating them.
`changed_attribute_names_to_save` is called in `keys_for_partial_write`,
which is called on every save when partial writes are enabled.
We can avoid generating the full changes hash by asking the mutation
tracker for just the names of the changed attributes. At minimum this
saves one array allocation per attribute, but will also avoid calling
`Attribute#original_value` which is expensive for serialized attributes.
For legacy reasons Rails stores time columns on sqlite as full
timestamp strings. However because the date component wasn't being
normalized this meant that when they were read back they were being
prefixed with 2001-01-01 by ActiveModel::Type::Time. This had a
twofold result - first it meant that the fast code path wasn't being
used because the string was invalid and second it was corrupting the
second fractional component being read by the Date._parse code path.
Fix this by a combination of normalizing the timestamps on writing
and also changing Active Model to be more lenient when detecting
whether a string starts with a date component before creating the
dummy time value for parsing.
In #20317, datetime columns had their precision applied on assignment but
that behaviour wasn't applied to time columns - this commit fixes that.
Fixes#30301.
This is an alternate implementation of #31698. That PR makes assumptions
that I do not want in the code base. We can fix the performance
regression with a much simpler patch.
This starts to fix#31832.
ActiveModel::Attributes includes ActiveModel::AttributeMethods,
which requires an `#attributes` method that returns a hash with string keys.
* PERF: Recover marshaling dump/load performance
This performance regression which is described in #30680 was caused by
f0ddf87 due to force materialized `LazyAttributeHash`.
Since 95b86e5, default proc has been removed in the class, so it is no
longer needed that force materialized.
Avoiding force materialized will recover marshaling dump/load
performance.
Benchmark:
https://gist.github.com/blimmer/1360ea51cd3147bae8aeb7c6d09bff17
Before:
```
it took 0.6248569069430232 seconds to unmarshal the objects
Total allocated: 38681544 bytes (530060 objects)
allocated memory by class
-----------------------------------
12138848 Hash
10542384 String
7920000 ActiveModel::Attribute::Uninitialized
5600000 ActiveModel::Attribute::FromDatabase
1200000 Foo
880000 ActiveModel::LazyAttributeHash
400000 ActiveModel::AttributeSet
80 Integer
72 ActiveRecord::ConnectionAdapters::SQLite3Adapter::SQLite3Integer
40 ActiveModel::Type::String
40 ActiveRecord::Type::DateTime
40 Object
40 Range
allocated objects by class
-----------------------------------
250052 String
110000 ActiveModel::Attribute::Uninitialized
70001 Hash
70000 ActiveModel::Attribute::FromDatabase
10000 ActiveModel::AttributeSet
10000 ActiveModel::LazyAttributeHash
10000 Foo
2 Integer
1 ActiveModel::Type::String
1 ActiveRecord::ConnectionAdapters::SQLite3Adapter::SQLite3Integer
1 ActiveRecord::Type::DateTime
1 Object
1 Range
```
After:
```
it took 0.1660824950085953 seconds to unmarshal the objects
Total allocated: 13883811 bytes (220090 objects)
allocated memory by class
-----------------------------------
5743371 String
4940008 Hash
1200000 Foo
880000 ActiveModel::LazyAttributeHash
720000 Array
400000 ActiveModel::AttributeSet
80 ActiveModel::Attribute::FromDatabase
80 Integer
72 ActiveRecord::ConnectionAdapters::SQLite3Adapter::SQLite3Integer
40 ActiveModel::Type::String
40 ActiveModel::Type::Value
40 ActiveRecord::Type::DateTime
40 Object
40 Range
allocated objects by class
-----------------------------------
130077 String
50004 Hash
10000 ActiveModel::AttributeSet
10000 ActiveModel::LazyAttributeHash
10000 Array
10000 Foo
2 Integer
1 ActiveModel::Attribute::FromDatabase
1 ActiveModel::Type::String
1 ActiveModel::Type::Value
1 ActiveRecord::ConnectionAdapters::SQLite3Adapter::SQLite3Integer
1 ActiveRecord::Type::DateTime
1 Object
1 Range
```
Fixes#30680.
* Keep the `@delegate_hash` to avoid to lose any mutations that have been made to the record
We don't implement much custom marshalling logic for these objects, but
the proc default case needs to be handled separately. Unfortunately
there's no way to just say "do what you would have done but with this
value for one ivar", so we have to manually implement `marshal_load` as
well.
The test case is a little bit funky, but I'd really like an equality
test in there, and there's no easy way to add one now that this is out
of AR (since the `attributes` method isn't here)
Fixes#31216
`define_attribute_methods` splats the arguments,
then calls out to `define_attribute_method` for
each. When defining a singule attribute, using
the singular version of the method saves us an
array and an extra method call.
#30985 caused `object.save` performance regression since calling
`changes` in `changes_applied` is very slow.
We don't need to call the expensive method in `changes_applied` as long
as `@attributes` is tracked by mutation tracker.
https://gist.github.com/kamipo/1a9f4f3891803b914fc72ede98268aa2
Before:
```
Warming up --------------------------------------
create_string_columns
73.000 i/100ms
Calculating -------------------------------------
create_string_columns
722.256 (± 5.8%) i/s - 3.650k in 5.073031s
```
After:
```
Warming up --------------------------------------
create_string_columns
96.000 i/100ms
Calculating -------------------------------------
create_string_columns
950.224 (± 7.7%) i/s - 4.800k in 5.084837s
```
I found a bug that validation callbacks don't fire on multiple context.
So I've fixed it.
Example:
```ruby
class Dog
include ActiveModel::Validations
include ActiveModel::Validations::Callbacks
attr_accessor :history
def initialize
@history = []
end
before_validation :set_before_validation_on_a, on: :a
before_validation :set_before_validation_on_b, on: :b
after_validation :set_after_validation_on_a, on: :a
after_validation :set_after_validation_on_b, on: :b
def set_before_validation_on_a; history << "before_validation on a"; end
def set_before_validation_on_b; history << "before_validation on b"; end
def set_after_validation_on_a; history << "after_validation on a" ; end
def set_after_validation_on_b; history << "after_validation on b" ; end
end
```
Before:
```
d = Dog.new
d.valid?([:a, :b])
d.history # []
```
After:
```
d = Dog.new
d.valid?([:a, :b])
d.history # ["before_validation on a", "before_validation on b", "after_validation on a", "after_validation on b"]
```
There are two concerns which are both being combined into one here, but
both have the same goal. There are certain attributes which we want to
always consider initialized. Previously, they were handled separately.
The primary key (which is assumed to be backed by a database column)
needs to be initialized, because there is a ton of code in Active Record
that assumes `foo.id` will never raise. Additionally, we want attributes
which aren't backed by a database column to always be initialized, since
we would never receive a database value for them.
Ultimately these two concerns can be combined into one. The old
implementation hid a lot of inherent complexity, and is hard to optimize
from the outside. We can simplify things significantly by just passing
in a hash.
This has slightly different semantics from the old behavior, in that
`Foo.select(:bar).first.id` will return the default value for the
primary key, rather than `nil` unconditionally -- however, the default
value is always `nil` in practice.
Currently, executing the test with only `attribute_test.rb` results in an error.
```
./bin/test -w test/cases/attribute_test.rb
Run options: --seed 41205
# Running:
....E
Error:
ActiveModel::AttributeTest#test_attributes_do_not_equal_attributes_with_different_types:
NameError: uninitialized constant ActiveModel::AttributeTest::Type
rails/activemodel/test/cases/attribute_test.rb:159:in `block in <class:AttributeTest>'
bin/test test/cases/attribute_test.rb:158
```
Added a missing require to fix this.
