Add extend_from_iter into growable trait

[sundy-li]

Did not achieve expected performance.

growable::primitive::non_null::non_null                                                                             
                        time:   [2.5629 us 2.5658 us 2.5692 us]

growable::dyn_primitive::non_null::non_null                                                                             
                        time:   [6.3092 us 6.3195 us 6.3328 us]
			
			
After:

growable::dyn_primitive::non_null::non_null                                                                             
                        time:   [6.0020 us 6.0147 us 6.0300 us]

We can't make extend_from_iter accept generic iterator, it'll make this trait none object-safety.

Fixes #772

[codecov]

Codecov Report

Merging #773 (e235988) into main (b70483e) will decrease coverage by 0.00%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #773      +/-   ##
==========================================
- Coverage   70.99%   70.99%   -0.01%     
==========================================
  Files         316      316              
  Lines       16733    16736       +3     
==========================================
+ Hits        11879    11881       +2     
- Misses       4854     4855       +1     

Impacted Files	Coverage Δ
src/array/growable/mod.rs	20.37% <0.00%> (-1.20%)	⬇️
src/io/parquet/read/nested_utils.rs	78.43% <0.00%> (+0.98%)	⬆️
src/io/avro/read/schema.rs	55.91% <0.00%> (+1.07%)	⬆️

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[sundy-li]

packed_simd is broken in the latest rust nightly toolchain.

databendlabs/databend#3882

[Xuanwo]

BTW, packed_simd seems superseded by stdsimd.

[ritchie46]

BTW, packed_simd seems superseded by stdsimd.

We know. See #747. There still are some blockers on that.

[jorgecarleitao]

Yeap, I think that this won't work as intended because .extend will still be dynamically dispatched.

We do something like what you intend here: https://github.com/jorgecarleitao/arrow2/blob/main/src/compute/filter.rs#L87

Essentially, specialize the implementation based on the physical type, and use a generic one (https://github.com/jorgecarleitao/arrow2/blob/main/src/compute/filter.rs#L101) for all others.

[sundy-li]

https://users.rust-lang.org/t/is-this-a-curiously-recurring-template-pattern/31004/6

As User @ExpHP said:

trait Trait {
    fn foo(&mut self);
    fn call_foo_twice(&mut self) {
        self.foo(); // <-- this is statically dispatched
        self.foo();
    }

    fn wrap(self) -> Wrapper<Self> { // <-- we can name Self
        Wrapper(self)
    }
}

so .extend is statically dispatched?

[jorgecarleitao]

An idea: create a simple function pub fn from_slice_iterator<A: AsRef<dyn Array>, I:Iterator>(&[A], iter: I) -> Box<dyn Array> that matches the arrays' logical type, downcasts them, initializes the static-typed growable, and extend it from the iterator.

[zirconium-n]

This should be done via extension trait to avoid object safety issue.

[sundy-li]

closing to search for better ideas.