32 lines
1.2 KiB
Swift
32 lines
1.2 KiB
Swift
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import Foundation
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struct RetryPolicy {
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let maxAttempts: Int
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let baseDelay: TimeInterval
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let maxDelay: TimeInterval
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let shouldRetry: (Error) -> Bool
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static let fileSave = RetryPolicy(maxAttempts: 4, baseDelay: 0.25, maxDelay: 4.0) { _ in true }
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static let network = RetryPolicy(maxAttempts: 3, baseDelay: 0.5, maxDelay: 8.0) { error in
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let retryable: Set<Int> = [NSURLErrorTimedOut, NSURLErrorNetworkConnectionLost,
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NSURLErrorNotConnectedToInternet, NSURLErrorCannotConnectToHost]
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return retryable.contains((error as NSError).code)
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}
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}
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func withRetry<T>(policy: RetryPolicy, operation: @escaping () async throws -> T) async throws -> T {
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var lastError: Error?
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var delay = policy.baseDelay
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for attempt in 1...policy.maxAttempts {
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do { return try await operation() }
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catch {
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lastError = error
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guard policy.shouldRetry(error), attempt < policy.maxAttempts else { break }
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let jitter = Double.random(in: 0...0.3) * delay
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try? await Task.sleep(for: .seconds(min(delay + jitter, policy.maxDelay)))
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delay = min(delay * 2, policy.maxDelay)
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}
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}
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throw lastError ?? URLError(.unknown)
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}
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