Various improvements to Classes, oriented around reducing allocations

[Lucretiel]

Description

• push no longer performs unnecessary allocations if self is empty. - Most constructors (FromIterator, From, Extend) that were already based around Into<Classes> are now oriented around push, to take advantage of this
• to_string and into_prop_value:
  • No longer allocate an unnecessary Vec; they instead preallocate a string of the correct length and push into it directly.
  • No longer use a length check + unsafe; they instead match over a fallible .next() and proceed from there.
  • Additionally, into_prop_value no longer builds a String or Rc if Classes contains a single &'static str or is empty.
• From<String> no longer clones the string if it contains a single class.
  • This mainly benefits FromIterator<String> and Iterator<&str>.map(to_owned)
• impl Eq for Classes

Checklist

• I have reviewed my own code
• I have added tests

[Lucretiel]

Note: in the future, as a slightly breaking change, we should consider redoing some of the implementation patterns around Classes construction, especially around FromIterator and Extend, which currently perform a lot of unnecessary intermediary allocations (because each item in the iterator is converted into a new Classes, which is then merged into the local one.

[github-actions]

Visit the preview URL for this PR (updated for commit 2016989):

https://yew-rs-api--pr2870-improved-classes-psuc2ffr.web.app

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[github-actions]

Benchmark - SSR

Yew Master

Benchmark	Round	Min (ms)	Max (ms)	Mean (ms)	Standard Deviation
Baseline	10	345.542	346.629	346.056	0.377
Hello World	10	598.836	601.203	599.581	0.640
Function Router	10	2256.107	2294.039	2268.111	11.198
Concurrent Task	10	1008.154	1010.020	1008.985	0.706

Pull Request

Benchmark	Round	Min (ms)	Max (ms)	Mean (ms)	Standard Deviation
Baseline	10	307.253	308.576	307.776	0.427
Hello World	10	602.793	627.080	605.853	7.493
Function Router	10	2224.540	2239.502	2230.902	4.526
Concurrent Task	10	1008.441	1010.044	1009.290	0.635

[github-actions]

Size Comparison

examples	master (KB)	pull request (KB)	diff (KB)	diff (%)
boids	170.231	170.229	-0.002	-0.001%
communication_child_to_parent	90.467	90.468	+0.001	+0.001%
communication_grandchild_with_grandparent	105.416	105.428	+0.012	+0.011%
communication_grandparent_to_grandchild	101.318	101.310	-0.009	-0.009%
communication_parent_to_child	87.606	87.604	-0.002	-0.002%
contexts	107.848	107.852	+0.004	+0.004%
counter	85.480	85.477	-0.004	-0.005%
counter_functional	86.010	86.007	-0.003	-0.003%
dyn_create_destroy_apps	88.380	88.380	0	0.000%
file_upload	100.059	100.059	0	0.000%
function_memory_game	163.776	163.145	-0.632	-0.386%
function_router	348.591	347.832	-0.759	-0.218%
function_todomvc	158.617	157.930	-0.688	-0.433%
futures	221.967	222.308	+0.341	+0.154%
game_of_life	105.718	105.030	-0.688	-0.650%
immutable	181.698	181.695	-0.003	-0.002%
inner_html	82.346	82.344	-0.002	-0.002%
js_callback	111.382	111.366	-0.016	-0.014%
keyed_list	195.565	195.560	-0.006	-0.003%
mount_point	85.099	85.097	-0.002	-0.002%
nested_list	112.600	111.926	-0.674	-0.598%
node_refs	92.984	92.990	+0.006	+0.006%
password_strength	1547.438	1547.438	0	0.000%
portals	96.291	96.291	0	0.000%
router	318.268	317.483	-0.784	-0.246%
simple_ssr	152.193	152.197	+0.004	+0.003%
ssr_router	394.141	393.386	-0.755	-0.192%
suspense	109.107	109.105	-0.002	-0.002%
timer	88.297	88.295	-0.002	-0.002%
todomvc	139.716	139.036	-0.680	-0.486%
two_apps	86.091	86.091	0	0.000%
web_worker_fib	152.230	152.231	+0.001	+0.001%
webgl	84.785	84.785	0	0.000%

✅ None of the examples has changed their size significantly.

[futursolo]

Thank you for the pull request.

[futursolo]

Thank you for the pull request. Looks good to me.

Cost of creating 1,000,000 Classes with 5 classes and convert them to a String:

Round: 1 (Warm up)
&'static str (pull request): 439ms
&'static str (master): 404ms
String (pull request): 673ms
String (master): 679ms
Round: 2
&'static str (pull request): 399ms
&'static str (master): 403ms
String (pull request): 673ms
String (master): 678ms
Round: 3
&'static str (pull request): 397ms
&'static str (master): 401ms
String (pull request): 676ms
String (master): 679ms
Round: 4
&'static str (pull request): 399ms
&'static str (master): 404ms
String (pull request): 669ms
String (master): 674ms
Round: 5
&'static str (pull request): 396ms
&'static str (master): 401ms
String (pull request): 668ms
String (master): 677ms

[ranile]

@futursolo how did you run the benchmarks? Can those be run as part alongside the other benchmarks that we have?