refactor: move chart refresh out of the component

Author: emrberk

src/hooks/useAdaptivePoll.ts

@@ -1,5 +1,67 @@
 import { useEffect, useRef, useState } from "react"
 
+type AdaptivePollLoopOptions = {
+  fetchFn: () => Promise<void>
+  signal: AbortSignal
+  minIntervalMs: number
+  maxIntervalMs: number
+  sampleSize?: number
+  multiplier?: number
+  skipInitialFetch?: boolean
+  onIntervalChange?: (intervalMs: number) => void
+}
+
+const sleep = (ms: number, signal: AbortSignal) =>
+  new Promise<void>((resolve, reject) => {
+    const timeoutId = setTimeout(resolve, ms)
+    signal.addEventListener("abort", () => {
+      clearTimeout(timeoutId)
+      reject(new DOMException("Aborted", "AbortError"))
+    })
+  })
+
+export const runAdaptivePollLoop = async ({
+  fetchFn,
+  signal,
+  minIntervalMs,
+  maxIntervalMs,
+  sampleSize = 3,
+  multiplier = 2,
+  skipInitialFetch = false,
+  onIntervalChange,
+}: AdaptivePollLoopOptions): Promise<void> => {
+  let samples: number[] = []
+  let skip = skipInitialFetch
+  while (!signal.aborted) {
+    let nextInterval = minIntervalMs
+    if (skip) {
+      // Data was just transferred in — wait one interval before the first
+      // background refresh instead of re-querying it immediately.
+      skip = false
+    } else {
+      const start = performance.now()
+      try {
+        await fetchFn()
+      } catch {
+        // fetchFn handles its own errors; never let one kill the loop
+      }
+      if (signal.aborted) break
+      samples = [...samples, performance.now() - start].slice(-sampleSize)
+      const avg = samples.reduce((a, b) => a + b, 0) / samples.length
+      nextInterval = Math.min(
+        maxIntervalMs,
+        Math.max(minIntervalMs, Math.round(avg * multiplier)),
+      )
+      onIntervalChange?.(nextInterval)
+    }
+    try {
+      await sleep(nextInterval, signal)
+    } catch {
+      break
+    }
+  }
+}
+
 type AdaptivePollOptions = {
   fetchFn: () => Promise<void>
   enabled: boolean
@@ -29,85 +91,28 @@ export const useAdaptivePoll = (
     getSkipInitialFetch,
   } = options
 
-  const samplesRef = useRef<number[]>([])
   const abortControllerRef = useRef<AbortController | null>(null)
   const [currentInterval, setCurrentInterval] = useState(minIntervalMs)
 
   useEffect(() => {
-    samplesRef.current = []
     setCurrentInterval(minIntervalMs)
-
-    // Abort any previous polling loop
-    if (abortControllerRef.current) {
-      abortControllerRef.current.abort()
-    }
+    abortControllerRef.current?.abort()
 
     if (!enabled) return
 
     const abortController = new AbortController()
     abortControllerRef.current = abortController
 
-    const calculateInterval = (samples: number[]): number => {
-      if (samples.length === 0) return minIntervalMs
-
-      const avg = samples.reduce((a, b) => a + b, 0) / samples.length
-      const calculated = avg * multiplier
-
-      return Math.min(
-        maxIntervalMs,
-        Math.max(minIntervalMs, Math.round(calculated)),
-      )
-    }
-
-    const sleep = (ms: number, signal: AbortSignal) =>
-      new Promise<void>((resolve, reject) => {
-        const timeoutId = setTimeout(resolve, ms)
-        signal.addEventListener("abort", () => {
-          clearTimeout(timeoutId)
-          reject(new DOMException("Aborted", "AbortError"))
-        })
-      })
-
-    const runPollingLoop = async () => {
-      let skipFetch = getSkipInitialFetch?.() ?? false
-      while (!abortController.signal.aborted) {
-        let nextInterval = minIntervalMs
-
-        if (skipFetch) {
-          // Data was just transferred in — wait one interval before the first
-          // background refresh instead of re-querying it immediately.
-          skipFetch = false
-        } else {
-          const startTime = performance.now()
-
-          try {
-            await fetchFn()
-          } catch (error) {
-            // Silently handle errors - the fetchFn should handle its own errors
-          }
-
-          // Check if we should stop after the fetch completed
-          if (abortController.signal.aborted) break
-
-          const responseTime = performance.now() - startTime
-          samplesRef.current = [...samplesRef.current, responseTime].slice(
-            -sampleSize,
-          )
-
-          nextInterval = calculateInterval(samplesRef.current)
-          setCurrentInterval(nextInterval)
-        }
-
-        try {
-          await sleep(nextInterval, abortController.signal)
-        } catch (error) {
-          // Sleep was aborted, exit the loop
-          break
-        }
-      }
-    }
-
-    void runPollingLoop()
+    void runAdaptivePollLoop({
+      fetchFn,
+      signal: abortController.signal,
+      minIntervalMs,
+      maxIntervalMs,
+      sampleSize,
+      multiplier,
+      skipInitialFetch: getSkipInitialFetch?.() ?? false,
+      onIntervalChange: setCurrentInterval,
+    })
 
     return () => {
       abortController.abort()