From 50e2b909f11382f2aaf1728be451a86eec827747 Mon Sep 17 00:00:00 2001
From: P0nk <ponkcode@gmail.com>
Date: Mon, 28 Jun 2021 12:29:01 +0200
Subject: [PATCH] Use Instant instead of long for time measurement

---
 .../coordinator/login/LoginStorage.java       | 68 ++++++++-----------
 .../session/MapleSessionCoordinator.java      |  2 +-
 2 files changed, 30 insertions(+), 40 deletions(-)

diff --git a/src/main/java/net/server/coordinator/login/LoginStorage.java b/src/main/java/net/server/coordinator/login/LoginStorage.java
index c4957f6899..d8e14e49f4 100644
--- a/src/main/java/net/server/coordinator/login/LoginStorage.java
+++ b/src/main/java/net/server/coordinator/login/LoginStorage.java
@@ -22,70 +22,60 @@ package net.server.coordinator.login;
 import config.YamlConfig;
 import net.server.Server;
 
+import java.time.Instant;
+import java.util.ArrayList;
 import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map.Entry;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
 
 /**
  *
  * @author Ronan
  */
 public class LoginStorage {
-    
-    private ConcurrentHashMap<Integer, List<Long>> loginHistory = new ConcurrentHashMap<>();
+    private final ConcurrentHashMap<Integer, List<Instant>> loginHistory = new ConcurrentHashMap<>(); // Key: accountId
     
     public boolean registerLogin(int accountId) {
-        List<Long> accHist = loginHistory.get(accountId);
-        if (accHist == null) {
-            accHist = new LinkedList<>();
-            loginHistory.put(accountId, accHist);
-        }
-        
-        synchronized (accHist) {
-            if (accHist.size() > YamlConfig.config.server.MAX_ACCOUNT_LOGIN_ATTEMPT) {
-                long blockExpiration = Server.getInstance().getCurrentTime() + YamlConfig.config.server.LOGIN_ATTEMPT_DURATION;
-                Collections.fill(accHist, blockExpiration);
+        List<Instant> attempts = loginHistory.computeIfAbsent(accountId, k -> new ArrayList<>());
 
+        synchronized (attempts) {
+            final Instant attemptExpiry = Instant.ofEpochMilli(Server.getInstance().getCurrentTime() + YamlConfig.config.server.LOGIN_ATTEMPT_DURATION);
+
+            if (attempts.size() > YamlConfig.config.server.MAX_ACCOUNT_LOGIN_ATTEMPT) {
+                Collections.fill(attempts, attemptExpiry);
                 return false;
             }
             
-            accHist.add(Server.getInstance().getCurrentTime() + YamlConfig.config.server.LOGIN_ATTEMPT_DURATION);
+            attempts.add(attemptExpiry);
             return true;
         }
     }
     
-    public void updateLoginHistory() {
-        long timeNow = Server.getInstance().getCurrentTime();
-        List<Integer> toRemove = new LinkedList<>();
-        List<Long> toRemoveAttempt = new LinkedList<>();
-        
-        for (Entry<Integer, List<Long>> loginEntries : loginHistory.entrySet()) {
-            toRemoveAttempt.clear();
-            
-            List<Long> accAttempts = loginEntries.getValue();
-            synchronized (accAttempts) {
-                for (Long loginAttempt : accAttempts) {
-                    if (loginAttempt < timeNow) {
-                        toRemoveAttempt.add(loginAttempt);
-                    }
+    public void clearExpiredAttempts() {
+        final Instant now = Instant.ofEpochMilli(Server.getInstance().getCurrentTime());
+        List<Integer> accountIdsToClear = new ArrayList<>();
+
+        for (Entry<Integer, List<Instant>> loginEntries : loginHistory.entrySet()) {
+            final List<Instant> attempts = loginEntries.getValue();
+            synchronized (attempts) {
+                List<Instant> attemptsToRemove = attempts.stream()
+                        .filter(attempt -> attempt.isBefore(now))
+                        .collect(Collectors.toList());
+
+                for (Instant attemptToRemove : attemptsToRemove) {
+                    attempts.remove(attemptToRemove);
                 }
 
-                if (!toRemoveAttempt.isEmpty()) {
-                    for (Long trAttempt : toRemoveAttempt) {
-                        accAttempts.remove(trAttempt);
-                    }
-
-                    if (accAttempts.isEmpty()) {
-                        toRemove.add(loginEntries.getKey());
-                    }
+                if (attempts.isEmpty()) {
+                    accountIdsToClear.add(loginEntries.getKey());
                 }
             }
         }
-        
-        for (Integer tr : toRemove) {
-            loginHistory.remove(tr);
+
+        for (Integer accountId : accountIdsToClear) {
+            loginHistory.remove(accountId);
         }
     }
 }
diff --git a/src/main/java/net/server/coordinator/session/MapleSessionCoordinator.java b/src/main/java/net/server/coordinator/session/MapleSessionCoordinator.java
index 07fca506a0..dc1e45ca7b 100644
--- a/src/main/java/net/server/coordinator/session/MapleSessionCoordinator.java
+++ b/src/main/java/net/server/coordinator/session/MapleSessionCoordinator.java
@@ -399,7 +399,7 @@ public class MapleSessionCoordinator {
     }
     
     public void runUpdateLoginHistory() {
-        loginStorage.updateLoginHistory();
+        loginStorage.clearExpiredAttempts();
     }
     
     public void printSessionTrace() {