perf(Subject): Don't clone observers array unless we have to #6842

benlesh · 2022-02-20T19:36:18Z

Previously we were cloning the observers array every time next was called on a Subject. This change attempts to reuse the same clone over and over until a new one is required because a new observer joined, or because an observer left.

I attempted to performance test this, and in terms of ops/sec it didn't show any real difference, but I didn't check memory pressure. Adding as a placeholder. I'm wondering what @cartant and @kwonoj think.

benlesh · 2022-02-20T20:04:58Z

After some review, it seems this reduces the memory pressure incurred by successive calls to Subject.next by between 30% and 50%. It also improves ops/sec performance by a modest amount (5-10% or so).

benlesh · 2022-02-20T20:06:42Z

src/internal/Subject.ts

-        const copy = this.observers.slice();
-        for (const observer of copy) {
+        if (!this.currentObservers) {
+          this.currentObservers = Array.from(this.observers);


The general idea is we only clone when currentObservers is null (invalidated) and then we use currentObservers when possible.

benlesh · 2022-02-20T20:07:05Z

src/internal/Subject.ts

+    if (hasError || isStopped) {
+      return EMPTY_SUBSCRIPTION;
+    }
+    this.currentObservers = null;


We invalidate currentObservers when we have a new subscriber

benlesh · 2022-02-20T20:07:24Z

src/internal/Subject.ts

+    this.currentObservers = null;
+    observers.push(subscriber);
+    return new Subscription(() => {
+      this.currentObservers = null;


We also invalidate currentObservers when anyone unsubscribes.

This PR contains the following updates: | Package | Type | Update | Change | |---|---|---|---| | [rxjs](https://rxjs.dev) ([source](https://github.com/reactivex/rxjs)) | dependencies | patch | [`7.5.4` -> `7.5.5`](https://renovatebot.com/diffs/npm/rxjs/7.5.4/7.5.5) | --- ### Release Notes <details> <summary>reactivex/rxjs</summary> ### [`v7.5.5`](https://github.com/reactivex/rxjs/blob/HEAD/CHANGELOG.md#755-httpsgithubcomreactivexrxjscompare754755-2022-03-08) [Compare Source](ReactiveX/rxjs@7.5.4...7.5.5) ##### Bug Fixes - **package:** add types to exports ([#6802](ReactiveX/rxjs#6802)) ([3750f75](ReactiveX/rxjs@3750f75)) - **package:** add `require` export condition ([#6821](ReactiveX/rxjs#6821)) ([c8955e4](ReactiveX/rxjs@c8955e4)) - **timeout:** no longer will timeout when receiving the first value synchronously ([#6865](ReactiveX/rxjs#6865)) ([2330c96](ReactiveX/rxjs@2330c96)), closes [#6862](ReactiveX/rxjs#6862) ##### Performance Improvements - Don't clone observers unless you have to ([#6842](ReactiveX/rxjs#6842)) ([3289d20](ReactiveX/rxjs@3289d20)) </details> --- ### Configuration 📅 **Schedule**: At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, click this checkbox. --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate). Co-authored-by: cabr2-bot <cabr2.help@gmail.com> Reviewed-on: https://codeberg.org/Calciumdibromid/CaBr2/pulls/1209 Reviewed-by: 6543 <6543@noreply.codeberg.org> Co-authored-by: Calciumdibromid Bot <cabr2_bot@noreply.codeberg.org> Co-committed-by: Calciumdibromid Bot <cabr2_bot@noreply.codeberg.org>

This PR contains the following updates: | Package | Type | Update | Change | |---|---|---|---| | [rxjs](https://rxjs.dev) ([source](https://github.com/reactivex/rxjs)) | dependencies | minor | [`7.5.7` -> `7.8.0`](https://renovatebot.com/diffs/npm/rxjs/7.5.7/7.8.0) | --- ### Release Notes <details> <summary>reactivex/rxjs</summary> ### [`v7.8.0`](https://github.com/reactivex/rxjs/blob/HEAD/CHANGELOG.md#780-httpsgithubcomreactivexrxjscompare770780-2022-12-15) [Compare Source](ReactiveX/rxjs@7.7.0...7.8.0) ##### Features - **buffer:** `closingNotifier` now supports any `ObservableInput` ([#7073](ReactiveX/rxjs#7073)) ([61b877a](ReactiveX/rxjs@61b877a)) - **delayWhen:** `delayWhen`'s `delayDurationSelector` now supports any `ObservableInput` ([#7049](ReactiveX/rxjs#7049)) ([dfd95db](ReactiveX/rxjs@dfd95db)) - **sequenceEqual:** `compareTo` now supports any `ObservableInput` ([#7102](ReactiveX/rxjs#7102)) ([d501961](ReactiveX/rxjs@d501961)) - **share:** `ShareConfig` factory properties now supports any `ObservableInput` ([#7093](ReactiveX/rxjs#7093)) ([cc3995a](ReactiveX/rxjs@cc3995a)) - **skipUntil:** `notifier` now supports any `ObservableInput` ([#7091](ReactiveX/rxjs#7091)) ([60d6c40](ReactiveX/rxjs@60d6c40)) - **window:** `windowBoundaries` now supports any `ObservableInput` ([#7088](ReactiveX/rxjs#7088)) ([8c4347c](ReactiveX/rxjs@8c4347c)) ### [`v7.7.0`](https://github.com/reactivex/rxjs/blob/HEAD/CHANGELOG.md#770-httpsgithubcomreactivexrxjscompare760770-2022-12-15) [Compare Source](ReactiveX/rxjs@7.6.0...7.7.0) ##### Features - **distinct:** `flush` argument now supports any `ObservableInput` ([#7081](ReactiveX/rxjs#7081)) ([74c9ebd](ReactiveX/rxjs@74c9ebd)) - **repeatWhen:** `notifier` supports `ObservableInput` ([#7103](ReactiveX/rxjs#7103)) ([8f1b976](ReactiveX/rxjs@8f1b976)) - **retryWhen:** `notifier` now supports any `ObservableInput` ([#7105](ReactiveX/rxjs#7105)) ([794f806](ReactiveX/rxjs@794f806)) - **sample:** `notifier` now supports any `ObservableInput` ([#7104](ReactiveX/rxjs#7104)) ([b18c2eb](ReactiveX/rxjs@b18c2eb)) ### [`v7.6.0`](https://github.com/reactivex/rxjs/blob/HEAD/CHANGELOG.md#760-httpsgithubcomreactivexrxjscompare757760-2022-12-03) [Compare Source](ReactiveX/rxjs@7.5.7...7.6.0) ##### Bug Fixes - **schedulers:** no longer cause TypeScript build failures when Node types aren't included ([c1a07b7](ReactiveX/rxjs@c1a07b7)) - **types:** Improved subscribe and tap type overloads ([#6718](ReactiveX/rxjs#6718)) ([af1a9f4](ReactiveX/rxjs@af1a9f4)), closes [#6717](ReactiveX/rxjs#6717) ##### Features - **onErrorResumeNextWith:** renamed `onErrorResumeNext` and exported from the top level. (`onErrorResumeNext` operator is stil available, but deprecated) ([#6755](ReactiveX/rxjs#6755)) ([51e3b2c](ReactiveX/rxjs@51e3b2c)) #### [7.5.7](ReactiveX/rxjs@7.5.6...7.5.7) (2022-09-25) ##### Bug Fixes - **schedulers:** improve performance of animationFrameScheduler and asapScheduler ([#7059](ReactiveX/rxjs#7059)) ([c93aa60](ReactiveX/rxjs@c93aa60)), closes [#7017](ReactiveX/rxjs#7017), related to [#7018](ReactiveX/rxjs#7018) and [#6674](ReactiveX/rxjs#6674) ##### Performance Improvements - **animationFrames:** uses fewer Subscription instances ([#7060](ReactiveX/rxjs#7060)) ([2d57b38](ReactiveX/rxjs@2d57b38)), closes [#7018](ReactiveX/rxjs#7018) #### [7.5.6](ReactiveX/rxjs@7.5.5...7.5.6) (2022-07-11) ##### Bug Fixes - **share:** No longer results in a bad-state observable in an edge case where a synchronous source was shared and refCounted, and the result is subscribed to twice in a row synchronously. ([#7005](ReactiveX/rxjs#7005)) ([5d4c1d9](ReactiveX/rxjs@5d4c1d9)) - **share & connect:** `share` and `connect` no longer bundle scheduling code by default ([#6873](ReactiveX/rxjs#6873)) ([9948dc2](ReactiveX/rxjs@9948dc2)), closes [#6872](ReactiveX/rxjs#6872) - **exhaustAll:** Result will now complete properly when flattening all synchronous observables. ([#6911](ReactiveX/rxjs#6911)) ([3c1c6b8](ReactiveX/rxjs@3c1c6b8)), closes [#6910](ReactiveX/rxjs#6910) - **TypeScript:** Now compatible with TypeScript 4.6 type checks ([#6895](ReactiveX/rxjs#6895)) ([fce9aa1](ReactiveX/rxjs@fce9aa1)) #### [7.5.5](ReactiveX/rxjs@7.5.4...7.5.5) (2022-03-08) ##### Bug Fixes - **package:** add types to exports ([#6802](ReactiveX/rxjs#6802)) ([3750f75](ReactiveX/rxjs@3750f75)) - **package:** add `require` export condition ([#6821](ReactiveX/rxjs#6821)) ([c8955e4](ReactiveX/rxjs@c8955e4)) - **timeout:** no longer will timeout when receiving the first value synchronously ([#6865](ReactiveX/rxjs#6865)) ([2330c96](ReactiveX/rxjs@2330c96)), closes [#6862](ReactiveX/rxjs#6862) ##### Performance Improvements - Don't clone observers unless you have to ([#6842](ReactiveX/rxjs#6842)) ([3289d20](ReactiveX/rxjs@3289d20)) #### [7.5.4](ReactiveX/rxjs@7.5.3...7.5.4) (2022-02-09) ##### Performance Improvements - removed code that would `bind` functions passed with observers to `subscribe`. ([#6815](ReactiveX/rxjs#6815)) ([fb375a0](ReactiveX/rxjs@fb375a0)), closes [#6783](ReactiveX/rxjs#6783) #### [7.5.3](ReactiveX/rxjs@7.5.2...7.5.3) (2022-02-08) ##### Bug Fixes - **subscribe:** allow interop with Monio and other libraries that patch function bind ([0ab91eb](ReactiveX/rxjs@0ab91eb)), closes [#6783](ReactiveX/rxjs#6783) #### [7.5.2](ReactiveX/rxjs@7.5.1...7.5.2) (2022-01-11) ##### Bug Fixes - operators that ignore input values now use `unknown` rather than `any`, which should resolve issues with eslint no-unsafe-argument ([#6738](ReactiveX/rxjs#6738)) ([67cb317](ReactiveX/rxjs@67cb317)), closes [#6536](ReactiveX/rxjs#6536) - **ajax:** crossDomain flag deprecated and properly reported to consumers ([#6710](ReactiveX/rxjs#6710)) ([7fd0575](ReactiveX/rxjs@7fd0575)), closes [#6663](ReactiveX/rxjs#6663) #### [7.5.1](ReactiveX/rxjs@7.5.0...7.5.1) (2021-12-28) ##### Bug Fixes - export supporting interfaces from top-level `rxjs` site. ([#6733](ReactiveX/rxjs#6733)) ([299a1e1](ReactiveX/rxjs@299a1e1)) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Co-authored-by: cabr2-bot <cabr2.help@gmail.com> Reviewed-on: https://codeberg.org/Calciumdibromid/CaBr2/pulls/1668 Reviewed-by: Epsilon_02 <epsilon_02@noreply.codeberg.org> Co-authored-by: Calciumdibromid Bot <cabr2_bot@noreply.codeberg.org> Co-committed-by: Calciumdibromid Bot <cabr2_bot@noreply.codeberg.org>

perf: Don't clone observers unless you have to

8aee7ff

benlesh requested review from cartant and kwonoj February 20, 2022 20:05

benlesh added 7.x Issues and PRs for version 7.x 8.x Issues and PRs for version 8.x labels Feb 20, 2022

benlesh commented Feb 20, 2022

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cartant approved these changes Feb 20, 2022

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kwonoj approved these changes Feb 20, 2022

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benlesh merged commit 3289d20 into ReactiveX:master Feb 21, 2022

patrickkunka mentioned this pull request Apr 21, 2022

Introduction of Non-ES5 APIs in ES5 Output in 7.5.5 #6942

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perf(Subject): Don't clone observers array unless we have to #6842

perf(Subject): Don't clone observers array unless we have to #6842

benlesh commented Feb 20, 2022

benlesh commented Feb 20, 2022

benlesh Feb 20, 2022

benlesh Feb 20, 2022

benlesh Feb 20, 2022

perf(Subject): Don't clone observers array unless we have to #6842

perf(Subject): Don't clone observers array unless we have to #6842

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