perf: Create Ante/Post handler chain once. #16076

lcwik · 2023-05-09T17:51:03Z

ChainAnteDecorators and ChainPostDecorators would create the chaining handler on each invocation repeatedly. This also had the code checking whether the terminator was at the end of the chain.

Creating all the handlers upfront and only once improved the performance of make test-sim-profile on my local machine from 133.2s to 132s for a ~1% performance improvement.

This is related to #14164 but maintains the existing recursive behavior.

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ChainAnteDecorators and ChainPostDecorators would create the chaining handler on each invocation repeatedly. This also had the code checking whether the terminator was at the end of the chain. Creating all the handlers upfront and only once improved the performance of `make test-sim-profile` on my local machine from 133.2s to 132s for a ~1% performance improvement. This is similar to cosmos#14164 but maintains the existing recursive behavior.

lcwik · 2023-05-09T17:59:15Z

types/handler.go

@@ -40,14 +40,18 @@ func ChainAnteDecorators(chain ...AnteDecorator) AnteHandler {
 		return nil
 	}

-	// handle non-terminated decorators chain
-	if (chain[len(chain)-1] != Terminator{}) {


Even though we don't use Terminator anymore, I didn't remove it to not break API compatibility with existing users.

Also I choose to use an AnteHandler implementation instead of an AnteDecorator to reduce the call depth by one for invocations that make it to the terminator.

lcwik · 2023-05-09T18:01:19Z

Waiting on reviewer to allow for the CI workflows to execute.

alexanderbez

Hey, thanks for the contribution @lcwik! Personally, I don't think the changes proposed, which harm legibility IMO, are worth the 1% gain.

lcwik · 2023-05-09T20:26:48Z

The gain is 1% for the whole simulation which means that this method represents an amount of overhead that is much higher than what it is effectively meant to do. I would agree with you if the 1% improvements was for just the method.

BrendanChou · 2023-05-11T20:23:03Z

@alexanderbez Hi Bez, @lcwik is pushing upstream the optimizations that we have in our own fork (dYdX's fork of Cosmos-SDK). This is a good-faith effort to:

improve the SDK for others without making breaking changes
remove our need to maintain a fork of the SDK (I know it's a general goal of the community to reduce the number of forks maintained of CometBFT and CosmosSDK)

Given the above, I would encourage you to reconsider the acceptance of this PR

types/handler.go

alexanderbez · 2023-05-15T13:59:25Z

types/handler.go

-	return func(ctx Context, tx Tx, simulate bool) (Context, error) {
-		return chain[0].AnteHandle(ctx, tx, simulate, ChainAnteDecorators(chain[1:]...))
+	for i := 0; i < len(chain); i++ {
+		ii := i


why are you setting an internal variable?

Suggested change

ii := i

The loop variable i would be captured by reference by the closure which is why we need use the local ii so that each iteration of the loop captures the current value and not the value the loop ends at. See https://oyvindsk.com/writing/common-golang-mistakes-1 for more details.

Ahh yes, I missed the func closure. Indeed that is correct.

types/handler.go

alexanderbez · 2023-05-15T14:00:08Z

types/handler.go

-	if (chain[len(chain)-1] != Terminator{}) {
-		chain = append(chain, Terminator{})
+	handlerChain := make([]PostHandler, len(chain)+1)
+	// Install the terminal PostHandler.


ditto on same changes as above :)

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>

lcwik · 2023-05-17T16:46:20Z

@alexanderbez PTAL

alexanderbez · 2023-05-17T17:54:36Z

types/handler.go

-	return func(ctx Context, tx Tx, simulate bool) (Context, error) {
-		return chain[0].AnteHandle(ctx, tx, simulate, ChainAnteDecorators(chain[1:]...))
+	for i := 0; i < len(chain); i++ {
+		ii := i


Ahh yes, I missed the func closure. Indeed that is correct.

alexanderbez · 2023-05-17T17:55:11Z

We'll have this backported on 0.47 as well.

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com> (cherry picked from commit 46119d1) # Conflicts: # CHANGELOG.md

lcwik · 2023-05-17T20:12:02Z

Thanks a bunch.

lcwik changed the title ~~fix: Create Ante/Post handler chain once.~~ perf: Create Ante/Post handler chain once. May 9, 2023

lcwik force-pushed the luke14164 branch from cabbd4a to e45d2c5 Compare May 9, 2023 17:56

lcwik commented May 9, 2023

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lcwik marked this pull request as ready for review May 9, 2023 18:00

lcwik requested a review from a team as a code owner May 9, 2023 18:00

github-prbot requested review from a team, kocubinski and tac0turtle and removed request for a team May 9, 2023 18:00

alexanderbez reviewed May 9, 2023

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alexanderbez reviewed May 15, 2023

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lcwik and others added 4 commits May 17, 2023 09:38

Update types/handler.go

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Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>

Update types/handler.go

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Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>

Address PR comments.

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Merge branch 'main' into luke14164

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alexanderbez approved these changes May 17, 2023

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alexanderbez added the backport/v0.47.x PR scheduled for inclusion in the v0.47's next stable release label May 17, 2023

alexanderbez enabled auto-merge May 17, 2023 17:55

alexanderbez added this pull request to the merge queue May 17, 2023

Merged via the queue into cosmos:main with commit 46119d1 May 17, 2023
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mergify bot pushed a commit that referenced this pull request May 17, 2023

perf: Create Ante/Post handler chain once. (#16076)

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Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com> (cherry picked from commit 46119d1) # Conflicts: # CHANGELOG.md

mergify bot mentioned this pull request May 17, 2023

perf: Create Ante/Post handler chain once. (backport #16076) #16200

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ValarDragon mentioned this pull request Jun 1, 2023

Speedup ChainAnteHandlers by making it non-recursive #14164

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perf: Create Ante/Post handler chain once. #16076

perf: Create Ante/Post handler chain once. #16076

lcwik commented May 9, 2023 •

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perf: Create Ante/Post handler chain once. #16076

perf: Create Ante/Post handler chain once. #16076

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lcwik commented May 9, 2023 • edited

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