A generic caching library for Swift

by iOS Example

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.

GitHub