Resolve more synchronization issues.

Notably, getLastOnline() is more in sync, putting a probable end to #23!

src/main/java/com/imaginarycode/minecraft/redisbungee/RedisBungee.java

@@ -317,34 +317,37 @@ public final class RedisBungee extends Plugin {
                 public void run() {
                     try (Jedis tmpRsc = pool.getResource()) {
                         Set<String> players = getLocalPlayersAsUuidStrings();
-                        Set<String> redisCollection = tmpRsc.smembers("proxy:" + configuration.getServerId() + ":usersOnline");
+                        Set<String> playersInRedis = tmpRsc.smembers("proxy:" + configuration.getServerId() + ":usersOnline");
 
-                        for (String member : redisCollection) {
+                        for (Iterator<String> it = playersInRedis.iterator(); it.hasNext(); ) {
+                            String member = it.next();
                             if (!players.contains(member)) {
                                 // Are they simply on a different proxy?
-                                boolean found = false;
+                                String found = null;
                                 for (String proxyId : getServerIds()) {
                                     if (proxyId.equals(configuration.getServerId())) continue;
                                     if (tmpRsc.sismember("proxy:" + proxyId + ":usersOnline", member)) {
                                         // Just clean up the set.
-                                        found = true;
+                                        found = proxyId;
                                         break;
                                     }
                                 }
-                                if (!found) {
+                                if (found == null) {
                                     RedisUtil.cleanUpPlayer(member, tmpRsc);
                                     getLogger().warning("Player found in set that was not found locally and globally: " + member);
                                 } else {
                                     tmpRsc.srem("proxy:" + configuration.getServerId() + ":usersOnline", member);
                                     getLogger().warning("Player found in set that was not found locally, but is on another proxy: " + member);
                                 }
+
+                                it.remove();
                             }
                         }
 
                         Pipeline pipeline = tmpRsc.pipelined();
 
                         for (String player : players) {
-                            if (redisCollection.contains(player))
+                            if (playersInRedis.contains(player))
                                 continue;
 
                             // Player not online according to Redis but not BungeeCord.
@@ -354,7 +357,7 @@ public final class RedisBungee extends Plugin {
                             if (proxiedPlayer == null)
                                 continue; // We'll deal with it later.
 
-                            RedisUtil.createPlayer(proxiedPlayer.getPendingConnection(), pipeline);
+                            RedisUtil.createPlayer(proxiedPlayer, pipeline);
                         }
 
                         pipeline.sync();

src/main/java/com/imaginarycode/minecraft/redisbungee/RedisBungeeListener.java

@@ -140,7 +140,6 @@ public class RedisBungeeListener implements Listener {
             protected Void call(Jedis jedis) {
                 Pipeline pipeline = jedis.pipelined();
                 long timestamp = System.currentTimeMillis();
-                pipeline.hset("player:" + event.getPlayer().getUniqueId().toString(), "online", String.valueOf(timestamp));
                 RedisUtil.cleanUpPlayer(event.getPlayer().getUniqueId().toString(), pipeline);
                 pipeline.publish("redisbungee-data", RedisBungee.getGson().toJson(new DataManager.DataManagerMessage<>(
                         event.getPlayer().getUniqueId(), DataManager.DataManagerMessage.Action.LEAVE,

src/main/java/com/imaginarycode/minecraft/redisbungee/RedisUtil.java

@@ -30,6 +30,7 @@ import com.google.common.annotations.VisibleForTesting;
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
 import net.md_5.bungee.api.connection.PendingConnection;
+import net.md_5.bungee.api.connection.ProxiedPlayer;
 import redis.clients.jedis.Jedis;
 import redis.clients.jedis.Pipeline;
 
@@ -39,6 +40,12 @@ import java.util.Map;
 @VisibleForTesting
 @NoArgsConstructor(access = AccessLevel.PRIVATE)
 public class RedisUtil {
+    protected static void createPlayer(ProxiedPlayer player, Pipeline pipeline) {
+        createPlayer(player.getPendingConnection(), pipeline);
+        if (player.getServer() != null)
+            pipeline.hset("player:" + player.getUniqueId().toString(), "server", player.getServer().getInfo().getName());
+    }
+
     protected static void createPlayer(PendingConnection connection, Pipeline pipeline) {
         Map<String, String> playerData = new HashMap<>(4);
         playerData.put("online", "0");
@@ -55,6 +62,8 @@ public class RedisUtil {
         rsc.hdel("player:" + player, "server");
         rsc.hdel("player:" + player, "ip");
         rsc.hdel("player:" + player, "proxy");
+        long timestamp = System.currentTimeMillis();
+        rsc.hset("player:" + player, "online", String.valueOf(timestamp));
     }
 
     public static void cleanUpPlayer(String player, Pipeline rsc) {
@@ -62,6 +71,8 @@ public class RedisUtil {
         rsc.hdel("player:" + player, "server");
         rsc.hdel("player:" + player, "ip");
         rsc.hdel("player:" + player, "proxy");
+        long timestamp = System.currentTimeMillis();
+        rsc.hset("player:" + player, "online", String.valueOf(timestamp));
     }
 
     public static boolean canUseLua(String redisVersion) {