Caching and versioning#

The caching mechanism in Re.Pack prevents chunk/script/container over-fetching, which helps reducing bandwidth usage, specially since they can easily take up multiple MBs od data.

Providing storage options to ChunkManager.configure(...) will enable caching of downloaded chunks/scripts/containers. The storage option accepts anything with similar API to AsyncStorage's getItem, setItem and removeItem functions.

By default, ChunkManager will compare the url returned by resolveRemoteChunk with the values stored in storage to determine if downloading if necessary. Skipping the download will only happen if the values are equal, meaning you can introduce versioning by changing the url, for example:

ChunkManager.configure({
  storage: AsyncStorage,
  resolveRemoteChunk: async (chunkId) => {
    const { version } = await getRemoteConfig();

    return {
      url: `http://my-domain.dev/v${version}/${chunkId}`,
    };
  },
});

Or by keeping the base URL inside remote config:

ChunkManager.configure({
  storage: AsyncStorage,
  resolveRemoteChunk: async (chunkId) => {
    const { baseURL } = await getRemoteConfig();

    return {
      url: `${baseURL}/${chunkId}`,
    };
  },
});

Usually cache invalidation happens automatically, but it's possible to invalidate chunk manually as well using ChunkManager.invalidateChunks(...) API which removes the chunks from filesystem and from the storage.