session-ios/SessionMessagingKit/Utilities/SSKIncrementingIdFinder.swift

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2020-11-11 00:58:56 +01:00
//
// Copyright (c) 2018 Open Whisper Systems. All rights reserved.
//
import Foundation
@objc
public class SSKIncrementingIdFinder: NSObject {
@objc
public static let collectionName = "IncrementingIdCollection"
@objc
public class func previousId(key: String, transaction: YapDatabaseReadTransaction) -> UInt64 {
let previousId: UInt64 = transaction.object(forKey: key, inCollection: collectionName) as? UInt64 ?? 0
return previousId
}
@objc
public class func nextId(key: String, transaction: YapDatabaseReadWriteTransaction) -> UInt64 {
let previousId: UInt64 = transaction.object(forKey: key, inCollection: collectionName) as? UInt64 ?? 0
let nextId: UInt64 = previousId + 1
transaction.setObject(nextId, forKey: key, inCollection: collectionName)
return nextId
}
}