https://github.com/githawkapp/flatcache

Implementation of Soroush Khanlou's Flat Cache.
https://github.com/githawkapp/flatcache

cache githawk swift

Last synced: 10 days ago
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Implementation of Soroush Khanlou's Flat Cache.

• Host: GitHub
• URL: https://github.com/githawkapp/flatcache
• Owner: GitHawkApp
• License: mit
• Created: 2018-01-03T03:09:50.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2018-10-30T19:32:07.000Z (about 6 years ago)
• Last Synced: 2024-10-31T16:26:28.558Z (16 days ago)
• Topics: cache, githawk, swift
• Language: Swift
• Homepage: http://khanlou.com/2017/10/the-flat-cache/
• Size: 29.3 KB
• Stars: 173
• Watchers: 5
• Forks: 15
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# FlatCache

Store any object in a flat cache by `String` id and notify listeners when changes occur.

This is an implementation of [Soroush Khanlou](https://twitter.com/khanlou)'s [The Flat Cache](http://khanlou.com/2017/10/the-flat-cache/) blog post used in [GitHawk](http://githawk.com).

## Installation

Just add `FlatCache` to your Podfile and pod install. Done!

```

pod 'FlatCache'

```

## Usage

Add the `Cachable` protocol to models that you want to store in the cache. Conform to the protocol by returning a `String` identifier used for lookup.

```swift

struct User {

  let name: String

}

extension User: Cachable {

  var id: String {

    return name

  }

}

```

> Don't worry about `id` collisions between objects. The cache "namespaces" different models by type.

Now just create a `FlatCache` object and start reading & writing with it.

```swift

let cache = FlatCache()

let user = User(name: "ryan")

cache.set(value: user)

if let cached = cache.get(id: user.id) as User? {

  print(cached.name) // "ryan"

}

```

> `FlatCache` uses the type information with the `get(id:)` function to lookup the appropriate object. You must type the result somehow.

### Listeners

One of the strengths of `FlatCache` is adding "listeners" to the cache to be notified when an object is changed. This powerful tool lets multiple systems respond to object changes.

```swift

let cache = FlatCache()

let user = User(name: "ryan")

let listener = MyUserListener()

cache.add(listener: listener, value: user)

```

Now whenever `user` is set again in the cache, `MyUserListener` will be notified with the following function:

```swift

func flatCacheDidUpdate(cache: FlatCache, update: FlatCache.Update) {

  switch update {

  case .item(let item):

    // just a single object updated

  case .list:

    // a list of subscribed objects updated

  }

}

```

> `FlatCache` coalesces so only a single event is delivered when something changes, no matter if an update has just a single object or hundreds.

## Acknowledgements

- Code used and inspired from [Soroush Khanlou](https://twitter.com/khanlou)'s [The Flat Cache](http://khanlou.com/2017/10/the-flat-cache/)

- Created with ❤️ by [Ryan Nystrom](https://twitter.com/_ryannystrom)