Function loadFromFile

src/hooks/useAsyncImageCache.ts:106–187

* Load an image file and create the cached result.

(
    imageFile: File,
    cacheKey: string,
    generation: number
  )

   * Load an image file and create the cached result.
   */
  async function loadFromFile(
    imageFile: File,
    cacheKey: string,
    generation: number
  ): Promise<T | null> {
    // Helper to clean up load tracking.
    // Only decrement activeLoads if we're still in the same generation.
    // If clear() was called (generation changed), it already reset activeLoads to 0.
    const cleanup = () => {
      if (generation === state.cacheGeneration) {
        state.activeLoads--;
        state.loadingPromises.delete(cacheKey);
        processQueue();
      }
    };

    try {
      // Skip images that have previously failed to decode
      if (hasImageFailed(cacheKey)) {
        cleanup();
        return null;
      }

      if (generation !== state.cacheGeneration) {
        // Don't call cleanup - clear() already reset state
        return null;
      }

      const cached = state.cache.get(cacheKey);
      if (cached) {
        cleanup();
        return cached;
      }

      let bitmap: ImageBitmap;
      try {
        const decodedBitmap = await createImageBitmapWithTimeout(imageFile, DECODE_TIMEOUT);
        bitmap = await resizeImageBitmapToMaxSizeWithTimeout(decodedBitmap, maxSize, DECODE_TIMEOUT);
      } catch (bitmapErr) {
        // Mark as failed so we don't retry (causes OOM with many failures)
        const failedCount = markImageFailed(cacheKey);
        // Only log first 20 failures to avoid console spam
        if (shouldLogDecodeFailure(failedCount)) {
          appLogger.warn(`[decode] Failed: "${cacheKey}" (${(imageFile.size / 1024).toFixed(0)} KB) -`, bitmapErr);
        } else if (shouldLogDecodeFailureSuppression(failedCount)) {
          appLogger.warn(`... suppressing further decode errors (${failedCount} images failed)`);
        }
        cleanup();
        return null;
      }

      if (generation !== state.cacheGeneration) {
        bitmap.close();
        // Don't call cleanup - clear() already reset state
        return null;
      }

      // Return promise that cleans up AFTER idle processing completes