Awesome Cache Delightful on-disk cache (written in Swift)
Awesome Cache
Delightful on-disk cache (written in Swift).
Backed by NSCache for maximum performance and support for expiry of single objects.
Usage
do {
let cache = try Cache<NSString>(name: "awesomeCache")
cache["name"] = "Alex"
let name = cache["name"]
cache["name"] = nil
} catch _ {
print("Something went wrong :(")
}
Sync by design
AwesomeCache >= 3.0 is designed to have a sync API, making it easy to reason about the actual contents of the cache. This decision has been made based on feedback from the community, to keep the API of AwesomeCache small and easy to use.
The internals of the cache use a concurrent dispatch queue, that syncs reads and writes for thread safety. In case a particular caching operation blocks your main thread for too long, consider offloading the read and write operations to a different thread.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
cache["name"] = "Alex"
}
Cache expiry
Objects can also be cached for a certain period of time.
cache.setObject("Alex", forKey: "name", expires: .never) // same as cache["name"] = "Alex"
cache.setObject("Alex", forKey: "name", expires: .seconds(2)) // name expires in 2 seconds
cache.setObject("Alex", forKey: "name", expires: .date(Date(timeIntervalSince1970: 1428364800))) // name expires on 4th of July 2015
If an object is accessed after its expiry date, it is automatically removed from the cache and deleted from disk.
However, you are responsible to delete expired objects regularly by calling removeExpiredObjects (e.g. on app launch).
Awesome API Caching
API responses are usually cached for a specific period of time. AwesomeCache provides an easy method to cache a block of asynchronous tasks.
cache.setObject(forKey: "name", cacheBlock: { success, failure in
// Perform tasks, e.g. call an API
let response = ...
success(response, .seconds(300)) // Cache response for 5 minutes
// ... or failure(error)
}, completion: { object, isLoadedFromCache, error in
if object {
// object is now cached
}
})
If the cache already contains an object, the completion block is called with the cached object immediately.
If no object is found or the cached object is already expired, the cacheBlock is called.
You may perform any tasks (e.g. network calls) within this block. Upon completion of these tasks, make sure to call the success or failure block that is passed to the cacheBlock. The cacheBlock will not be re-evaluated until the object is expired or manually deleted.
The completion block is invoked as soon as the cacheBlock is finished and the object is cached.
Version Compatibility
Current Swift compatibility breakdown:
| Swift Version | Framework Version |
|---|---|
| 3.0 | 5.x |
| 2.3 | 4.x |
| 2.2 | 3.x |
Installation
Carthage
Add the following line to your Cartfile.
github "aschuch/AwesomeCache"
Then run carthage update.
CocoaPods
Add the following line to your Podfile.
pod "AwesomeCache", "~> 3.0"
Then run pod install with CocoaPods 0.36 or newer.
Manually
Just drag and drop the two .swift files as well as the NSKeyedUnarchiverWrapper.h/.m files in the AwesomeCache folder into your project.
If you are adding AwesomeCache to a Swift project, you also need to add an import for NSKeyedUnarchiverWrapper.h to your bridging header.
Tests
Open the Xcode project and press ⌘-U to run the tests.
Alternatively, all tests can be run in the terminal using xctool.
xctool -scheme AwesomeCacheTests -sdk iphonesimulator test
Contributing
- Create something awesome, make the code better, add some functionality,
whatever (this is the hardest part). - Fork it
- Create new branch to make your changes
- Commit all your changes to your branch
- Submit a pull request
Contact
Feel free to get in touch.