Generic Caching class For RxSwift
The latest version of the class can always be found at: https://gist.github.com/dtartaglia/bf24b3b59dd33fef4cfa568d0e47f91b
Did I miss anything? Is there anything I can do to make the code more lean or more reusable? Ideas for better names?
//
// RxCache.swift
//
// Created by Daniel Tartaglia on 12/20/18.
// Copyright © 2018 Daniel Tartaglia. MIT License.
//
import RxSwift
final class Cache<Key: Hashable, State> {
init(qos: DispatchQoS, source: @escaping (Key) -> Single<State>) {
scheduler = SerialDispatchQueueScheduler(qos: qos)
getState = source
}
func data(for key: Key) -> Single<State> {
lock.lock(); defer { lock.unlock() }
guard let state = cache[key] else {
let state = ReplaySubject<State>.create(bufferSize: 1)
getState(key)
.observeOn(scheduler)
.subscribe(
onSuccess: { state.onNext($0) },
onError: { [weak self] _ in
guard let this = self else { return }
this.lock.lock(); defer { this.lock.unlock() }
this.cache.removeValue(forKey: key)
}
)
.disposed(by: bag)
cache[key] = state
return state.asSingle()
}
return state.asSingle()
}
private var cache: [Key: ReplaySubject<State>] = [:]
private let scheduler: SerialDispatchQueueScheduler
private let lock = NSRecursiveLock()
private let getState: (Key) -> Single<State>
private let bag = DisposeBag()
}
The scheduler exists because Subjects aren't thread safe and I have no way of knowing what thread getData might be emitting on.
The lock exists because I don't want to create multiple responses for the same key in the event that the date(for:) method is called from multiple threads.
I added code to handle errors. Errors don't exit the class but they do remove the cache object so the next attempt will create a new ReplaySubject.
swift rx-swift
asked Dec 20 at 14:40
Daniel T.
521313
add a comment |
The latest version of the class can always be found at: https://gist.github.com/dtartaglia/bf24b3b59dd33fef4cfa568d0e47f91b
Did I miss anything? Is there anything I can do to make the code more lean or more reusable? Ideas for better names?
//
// RxCache.swift
//
// Created by Daniel Tartaglia on 12/20/18.
// Copyright © 2018 Daniel Tartaglia. MIT License.
//
import RxSwift
final class Cache<Key: Hashable, State> {
init(qos: DispatchQoS, source: @escaping (Key) -> Single<State>) {
scheduler = SerialDispatchQueueScheduler(qos: qos)
getState = source
}
func data(for key: Key) -> Single<State> {
lock.lock(); defer { lock.unlock() }
guard let state = cache[key] else {
let state = ReplaySubject<State>.create(bufferSize: 1)
getState(key)
.observeOn(scheduler)
.subscribe(
onSuccess: { state.onNext($0) },
onError: { [weak self] _ in
guard let this = self else { return }
this.lock.lock(); defer { this.lock.unlock() }
this.cache.removeValue(forKey: key)
}
)
.disposed(by: bag)
cache[key] = state
return state.asSingle()
}
return state.asSingle()
}
private var cache: [Key: ReplaySubject<State>] = [:]
private let scheduler: SerialDispatchQueueScheduler
private let lock = NSRecursiveLock()
private let getState: (Key) -> Single<State>
private let bag = DisposeBag()
}
The scheduler exists because Subjects aren't thread safe and I have no way of knowing what thread getData might be emitting on.
The lock exists because I don't want to create multiple responses for the same key in the event that the date(for:) method is called from multiple threads.
I added code to handle errors. Errors don't exit the class but they do remove the cache object so the next attempt will create a new ReplaySubject.
swift rx-swift
asked Dec 20 at 14:40
Daniel T.
521313
add a comment |
The latest version of the class can always be found at: https://gist.github.com/dtartaglia/bf24b3b59dd33fef4cfa568d0e47f91b
Did I miss anything? Is there anything I can do to make the code more lean or more reusable? Ideas for better names?
//
// RxCache.swift
//
// Created by Daniel Tartaglia on 12/20/18.
// Copyright © 2018 Daniel Tartaglia. MIT License.
//
import RxSwift
final class Cache<Key: Hashable, State> {
init(qos: DispatchQoS, source: @escaping (Key) -> Single<State>) {
scheduler = SerialDispatchQueueScheduler(qos: qos)
getState = source
}
func data(for key: Key) -> Single<State> {
lock.lock(); defer { lock.unlock() }
guard let state = cache[key] else {
let state = ReplaySubject<State>.create(bufferSize: 1)
getState(key)
.observeOn(scheduler)
.subscribe(
onSuccess: { state.onNext($0) },
onError: { [weak self] _ in
guard let this = self else { return }
this.lock.lock(); defer { this.lock.unlock() }
this.cache.removeValue(forKey: key)
}
)
.disposed(by: bag)
cache[key] = state
return state.asSingle()
}
return state.asSingle()
}
private var cache: [Key: ReplaySubject<State>] = [:]
private let scheduler: SerialDispatchQueueScheduler
private let lock = NSRecursiveLock()
private let getState: (Key) -> Single<State>
private let bag = DisposeBag()
}
The scheduler exists because Subjects aren't thread safe and I have no way of knowing what thread getData might be emitting on.
The lock exists because I don't want to create multiple responses for the same key in the event that the date(for:) method is called from multiple threads.
I added code to handle errors. Errors don't exit the class but they do remove the cache object so the next attempt will create a new ReplaySubject.
swift rx-swift
asked Dec 20 at 14:40
Daniel T.
521313
The latest version of the class can always be found at: https://gist.github.com/dtartaglia/bf24b3b59dd33fef4cfa568d0e47f91b
Did I miss anything? Is there anything I can do to make the code more lean or more reusable? Ideas for better names?
//
// RxCache.swift
//
// Created by Daniel Tartaglia on 12/20/18.
// Copyright © 2018 Daniel Tartaglia. MIT License.
//
import RxSwift
final class Cache<Key: Hashable, State> {
init(qos: DispatchQoS, source: @escaping (Key) -> Single<State>) {
scheduler = SerialDispatchQueueScheduler(qos: qos)
getState = source
}
func data(for key: Key) -> Single<State> {
lock.lock(); defer { lock.unlock() }
guard let state = cache[key] else {
let state = ReplaySubject<State>.create(bufferSize: 1)
getState(key)
.observeOn(scheduler)
.subscribe(
onSuccess: { state.onNext($0) },
onError: { [weak self] _ in
guard let this = self else { return }
this.lock.lock(); defer { this.lock.unlock() }
this.cache.removeValue(forKey: key)
}
)
.disposed(by: bag)
cache[key] = state
return state.asSingle()
}
return state.asSingle()
}
private var cache: [Key: ReplaySubject<State>] = [:]
private let scheduler: SerialDispatchQueueScheduler
private let lock = NSRecursiveLock()
private let getState: (Key) -> Single<State>
private let bag = DisposeBag()
}
The scheduler exists because Subjects aren't thread safe and I have no way of knowing what thread getData might be emitting on.
The lock exists because I don't want to create multiple responses for the same key in the event that the date(for:) method is called from multiple threads.
I added code to handle errors. Errors don't exit the class but they do remove the cache object so the next attempt will create a new ReplaySubject.
swift rx-swift
swift rx-swift
asked Dec 20 at 14:40
Daniel T.
521313
asked Dec 20 at 14:40
Daniel T.
521313
edited Dec 22 at 0:58
asked Dec 20 at 14:40
Daniel T.
521313
asked Dec 20 at 14:40
Daniel T.
521313
asked Dec 20 at 14:40
Daniel T.
521313
521313
add a comment |
add a comment |
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