Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Record computation time #622

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 16 additions & 2 deletions src/index.ts
Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,14 @@ export function setInputStabilityCheckEnabled(enabled: StabilityCheck) {
globalStabilityCheck = enabled
}

function getTime() {

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I am wondering if wouldn't be better if definition of getTime would look like:

const getTime = performance && typeof performance.now === 'function'
  ? performance.now.bind(performance)
  : Date.now.bind(Date)

In that case no extra conditions or jumps will be done while the function executes.

if (performance && typeof performance.now === 'function') {
return performance.now()
}

return Date.now()
}

function getDependencies(funcs: unknown[]) {
const dependencies = Array.isArray(funcs[0]) ? funcs[0] : funcs

Expand Down Expand Up @@ -79,6 +87,7 @@ export function createSelectorCreator<
) {
const createSelector = (...funcs: Function[]) => {
let recomputations = 0
let computationTime = 0
let lastResult: unknown

// Due to the intricacies of rest params, we can't do an optional arg after `...funcs`.
Expand Down Expand Up @@ -121,8 +130,12 @@ export function createSelectorCreator<
const memoizedResultFunc = memoize(
function recomputationWrapper() {
recomputations++
const computationStartTime = getTime()
// apply arguments instead of spreading for performance.
return resultFunc!.apply(null, arguments)
const resultFuncOutput = resultFunc!.apply(null, arguments)
computationTime += getTime() - computationStartTime

return resultFuncOutput
} as F,
...finalMemoizeOptions
)
Expand Down Expand Up @@ -204,7 +217,8 @@ export function createSelectorCreator<
dependencies,
lastResult: () => lastResult,
recomputations: () => recomputations,
resetRecomputations: () => (recomputations = 0)
resetRecomputations: () => (recomputations = 0, computationTime = 0),
computationTime: () => computationTime
})

return selector
Expand Down
4 changes: 3 additions & 1 deletion src/types.ts
Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,9 @@ export interface OutputSelectorFields<Combiner extends UnknownFunction, Keys> {
dependencies: SelectorArray
/** Counts the number of times the output has been recalculated */
recomputations: () => number
/** Resets the count of recomputations count to 0 */
/** Total computation time of everytime the output has been recalculated */
computationTime: () => number
/** Resets the count of recomputations count and computation time to 0 */
resetRecomputations: () => number
}

Expand Down
45 changes: 44 additions & 1 deletion test/reselect.spec.ts
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@ import {
weakMapMemoize
} from 'reselect'
import lodashMemoize from 'lodash/memoize'
import { vi } from 'vitest'
import { afterAll, afterEach, beforeEach, describe, vi } from 'vitest'
import { configureStore, createSlice, PayloadAction } from '@reduxjs/toolkit'

// Construct 1E6 states for perf test outside of the perf test so as to not change the execute time of the test function
Expand Down Expand Up @@ -101,6 +101,49 @@ describe('Basic selector behavior', () => {
)
})

describe('computation time', () => {
const performanceSpy = vi.spyOn(performance, 'now')

beforeEach(() => {
performanceSpy
.mockReturnValueOnce(1500)
.mockReturnValueOnce(3000)
.mockReturnValueOnce(4500)
.mockReturnValueOnce(6000)
})

it('should records computation time for every re-computation', () => {
const selector = createSelector(
(state: StateAB) => state.a,
(state: StateAB) => state.b,
(a, b) => a + b
)
const state1 = { a: 1, b: 2 }
selector(state1)
expect(selector.computationTime()).toBe(1500)
const state2 = { a: 3, b: 2 }
selector(state2)
expect(selector.computationTime()).toBe(3000)
})

it('should reset computation time when calling resetRecomputations', () => {
const selector = createSelector(
(state: StateAB) => state.a,
(state: StateAB) => state.b,
(a, b) => a + b
)
const state1 = { a: 1, b: 2 }
selector(state1)
expect(selector.computationTime()).toBe(1500)
selector.resetRecomputations()
expect(selector.computationTime()).toBe(0)
})

afterEach(() => {
performanceSpy.mockClear()
})
})

describe('performance checks', () => {
const originalEnv = process.env.NODE_ENV

Expand Down