cwoloszynski / Cache

Swift caching library

Cache

A generic caching library for Swift. Cache depends on Foundation.

This is still very much a work in progress.

Usage

Cache provides a simple Cache protocol:

protocol Cache {
  associatedtype Element

  func get(key key: String, completion: (Element? -> Void))
  func set(key key: String, value: Element, completion: (() -> Void)?)
  func remove(key key: String, completion: (() -> Void)?)
  func removeAll(completion completion: (() -> Void)?)
}

There are two (well actually three, but we'll get there) provided caches:

• MemoryCache — Backed by an NSCache
• DiskCache — Backed by files on disk using NSFileManager

Using both of these is exactly the same interface.

MultiCache

There is a third cache provided called MultiCache. This combines caches.

let cache = MultiCache(caches: [memoryCache, diskCache])
cache.set(key: "foo", value: "bar")

This will write to all caches in parallel. When accessing the multi cache, it will go in order. In this example, it will try the memory cache and if there's a miss it will try the disk cache. If it were to find it in the disk cache, it will write it to all previous caches for faster future reads.

Thanks

Thanks to Caleb Davenport for unintentionally inspiring this and lots of help along the way.