Package g1701_1800.s1797_design_authentication_manager

Class AuthenticationManager

java.lang.Object

g1701_1800.s1797_design_authentication_manager.AuthenticationManager

public class AuthenticationManager
extends Object

1797 - Design Authentication Manager\. Medium There is an authentication system that works with authentication tokens. For each session, the user will receive a new authentication token that will expire `timeToLive` seconds after the `currentTime`. If the token is renewed, the expiry time will be **extended** to expire `timeToLive` seconds after the (potentially different) `currentTime`. Implement the `AuthenticationManager` class: * `AuthenticationManager(int timeToLive)` constructs the `AuthenticationManager` and sets the `timeToLive`. * `generate(string tokenId, int currentTime)` generates a new token with the given `tokenId` at the given `currentTime` in seconds. * `renew(string tokenId, int currentTime)` renews the **unexpired** token with the given `tokenId` at the given `currentTime` in seconds. If there are no unexpired tokens with the given `tokenId`, the request is ignored, and nothing happens. * `countUnexpiredTokens(int currentTime)` returns the number of **unexpired** tokens at the given currentTime. Note that if a token expires at time `t`, and another action happens on time `t` (`renew` or `countUnexpiredTokens`), the expiration takes place **before** the other actions. **Example 1:**  **Input** ["AuthenticationManager", "`renew`", "generate", "`countUnexpiredTokens`", "generate", "`renew`", "`renew`", "`countUnexpiredTokens`"] [[5], ["aaa", 1], ["aaa", 2], [6], ["bbb", 7], ["aaa", 8], ["bbb", 10], [15]] **Output:** [null, null, null, 1, null, null, null, 0] **Explanation:** AuthenticationManager authenticationManager = new AuthenticationManager(5); // Constructs the AuthenticationManager with `timeToLive` = 5 seconds. authenticationManager.`renew`("aaa", 1); // No token exists with tokenId "aaa" at time 1, so nothing happens. authenticationManager.generate("aaa", 2); // Generates a new token with tokenId "aaa" at time 2. authenticationManager.`countUnexpiredTokens`(6); // The token with tokenId "aaa" is the only unexpired one at time 6, so return 1. authenticationManager.generate("bbb", 7); // Generates a new token with tokenId "bbb" at time 7. authenticationManager.`renew`("aaa", 8); // The token with tokenId "aaa" expired at time 7, and 8 >= 7, so at time 8 the `renew` request is ignored, and nothing happens. authenticationManager.`renew`("bbb", 10); // The token with tokenId "bbb" is unexpired at time 10, so the `renew` request is fulfilled and now the token will expire at time 15. authenticationManager.`countUnexpiredTokens`(15); // The token with tokenId "bbb" expires at time 15, and the token with tokenId "aaa" expired at time 7, so currently no token is unexpired, so return 0. **Constraints:** * 1 <= timeToLive <= 108 * 1 <= currentTime <= 108 * `1 <= tokenId.length <= 5` * `tokenId` consists only of lowercase letters. * All calls to `generate` will contain unique values of `tokenId`. * The values of `currentTime` across all the function calls will be **strictly increasing**. * At most `2000` calls will be made to all functions combined.

Constructor Summary

Constructors

Constructor	Description
AuthenticationManager(int timeToLive)

Method Summary

Modifier and Type	Method	Description
int	countUnexpiredTokens(int currentTime)
void	generate(String tokenId, int currentTime)
void	renew(String tokenId, int currentTime)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

AuthenticationManager

public AuthenticationManager(int timeToLive)

Method Details

generate

public void generate(String tokenId,
 int currentTime)

renew

public void renew(String tokenId,
 int currentTime)

countUnexpiredTokens

public int countUnexpiredTokens(int currentTime)