39 lines
853 B
Swift
39 lines
853 B
Swift
//
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// DatabaseID.swift
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// NetNewsWire
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//
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// Created by Brent Simmons on 7/15/17.
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// Copyright © 2017 Ranchero Software. All rights reserved.
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//
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import Foundation
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import FoundationExtras
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class DatabaseIDCache: @unchecked Sendable {
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static let shared = DatabaseIDCache()
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private var databaseIDCache = [String: String]()
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private let databaseIDCacheLock = NSLock()
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/// Generates — or retrieves from cache — a database-suitable ID based on a String.
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func databaseIDWithString(_ s: String) -> String {
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databaseIDCacheLock.lock()
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defer {
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databaseIDCacheLock.unlock()
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}
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if let identifier = databaseIDCache[s] {
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return identifier
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}
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// MD5 works because:
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// * It’s fast
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// * Collisions aren’t going to happen with feed data
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let identifier = s.md5String
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databaseIDCache[s] = identifier
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return identifier
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}
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}
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