loadFromDiskCache method

Future<Uint8List?> loadFromDiskCache()

Load the disk cache

Check the following conditions: (no CacheRule)

1. Check if cache directory exist. If not exist, create it.
2. Check if cached file(uid) exist. If yes, load the cache, otherwise go to download step.

Implementation

Future<Uint8List?> loadFromDiskCache() async {
  AdvancedNetworkImage key = this;

  String uId = uid(key.url);

  if (key.cacheRule == null) {
    Directory _cacheImagesDirectory =
        Directory(join((await getTemporaryDirectory()).path, 'imagecache'));
    if (_cacheImagesDirectory.existsSync()) {
      File _cacheImageFile = File(join(_cacheImagesDirectory.path, uId));
      if (_cacheImageFile.existsSync()) {
        if (key.loadedFromDiskCacheCallback != null)
          key.loadedFromDiskCacheCallback!();
        return await _cacheImageFile.readAsBytes();
      }
    } else {
      await _cacheImagesDirectory.create();
    }

    Uint8List? imageData = await loadFromRemote(
      key.url,
      key.header,
      key.retryLimit,
      key.retryDuration,
      key.retryDurationFactor,
      key.timeoutDuration,
      key.loadingProgress,
      key.getRealUrl,
      skipRetryStatusCode: key.skipRetryStatusCode,
      printError: key.printError,
    );
    if (imageData != null) {
      if (key.preProcessing != null)
        imageData = (await key.preProcessing!(imageData)) ?? imageData;
      await (File(join(_cacheImagesDirectory.path, uId)))
          .writeAsBytes(imageData);
      return imageData;
    }
  } else {
    DiskCache diskCache = DiskCache()..printError = key.printError;
    Uint8List? data = await diskCache.load(uId, rule: key.cacheRule);
    if (data != null) {
      if (key.loadedFromDiskCacheCallback != null)
        key.loadedFromDiskCacheCallback!();
      return data;
    }

    data = await loadFromRemote(
      key.url,
      key.header,
      key.retryLimit,
      key.retryDuration,
      key.retryDurationFactor,
      key.timeoutDuration,
      key.loadingProgress,
      key.getRealUrl,
      printError: key.printError,
    );
    if (data != null) {
      if (key.preProcessing != null)
        data = (await key.preProcessing!(data)) ?? data;
      await diskCache.save(uId, data, key.cacheRule!);
      return data;
    }
  }

  return null;
}