perf(query-core): useQueries have quadratic performance in relation to the number of queries(#8604)

[zktm9903]

Task

issue
comment

Modification

This change optimizes the time complexity of the #onUpdate function in queriesObserver from O(n) to O(1).

  #onUpdate(observer: QueryObserver, result: QueryObserverResult): void {
    const index = this.#observerMap.get(observer)
    if (index !== undefined) {
      this.#result = replaceAt(this.#result, index, result)
      this.#notify()
    }
  }

[TkDodo]

I’m not a fan of storing the observers in both a Map and an Array, and the whole thing becomes more complex.

The only reason we have an Array is because users pass in Array<QueryObserverOptions>, and we need to keep that order. Maybe storing this as a Map<index, QueryObserver> only would work?