Counter refactoring

Plugins/Mineplex.Core/src/mineplex/core/brawl/fountain/Fountain.java

@@ -8,6 +8,7 @@ import mineplex.core.hologram.Hologram;
 import mineplex.core.hologram.HologramManager;
 import mineplex.core.stats.StatsManager;
 import mineplex.serverdata.redis.counter.Counter;
+import mineplex.serverdata.redis.counter.GoalCounter;
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
 
@@ -25,7 +26,7 @@ public class Fountain
 	private final Location _location;
 	private Location _lavaLocation;
 	private final Hologram _hologram;
-	private final Counter _counter;
+	private final GoalCounter _counter;
 
 	private final FountainShop _shop;
 
@@ -41,7 +42,7 @@ public class Fountain
 		_location = location;
 		_lavaLocation = lavaLocation;
 		_hologram = new Hologram(hologramManager, location.clone().add(0, 2, 0), name).start();
-		_counter = new Counter(dataKey, goal);
+		_counter = new GoalCounter(dataKey, 5000, goal);
 
 		_shop = new FountainShop(this, fountainManager, clientManager, donationManager);
 
@@ -56,19 +57,13 @@ public class Fountain
 
 	protected void updateCount()
 	{
-		// Make sure we only update if it has been 5 seconds since the last update
+		updateHologram();
-		// Players incrementing the counter will automatically cause it to update
-		if (System.currentTimeMillis() - _counter.getCacheLastUpdated() > 5000)
-		{
-			_counter.updateCount();
-			updateHologram();
-		}
 	}
 
 	public void increment(Player player, long amount)
 	{
 		_statsManager.incrementStat(player, "Global.Fountain." + getDataKey(), amount);
-		_counter.increment(amount);
+		_counter.addAndGet(amount);
 		updateHologram();
 	}
 

Plugins/Mineplex.ServerData/src/mineplex/serverdata/redis/counter/Counter.java

@@ -3,73 +3,100 @@ package mineplex.serverdata.redis.counter;
 import java.util.concurrent.atomic.AtomicLong;
 
 /**
- * A counter represents an atomic number that is trying to hit a goal. Once the counter
+ * A counter represents an incrementing atomic number that is stored and updated through redis. This allows for
- * reaches it's goal you can either reset it or let it stay completed for an indefinite time.
+ * multiple servers to share and update the same counter
  *
  * @author Shaun Bennett
  */
 public class Counter
 {
-	// Cached count for the fountain
+	// Cached count of the counter
-	private AtomicLong _count = new AtomicLong(0);
+	private final AtomicLong _count = new AtomicLong(0);
 	// The System.currentTimeMillis() when cached count was last updated
-	private long _cacheLastUpdated;
+	private volatile long _lastUpdated;
-	// The goal that this fountain is trying to reach
+	// The maximum time to wait before syncing the count with repository
-	private final long _goal;
+	private final long _syncTime;
 	// The unique key to reference this counter
 	private final String _dataKey;
 
 	// Redis repository to store the count
-	private CounterRedisRepository _redisRepository;
+	private final CounterRedisRepository _redisRepository;
 
-	public Counter(String dataKey, long goal)
+	public Counter(String dataKey, long syncTime)
 	{
-		_goal = goal;
 		_dataKey = dataKey;
+		_syncTime = syncTime;
 		_redisRepository = new CounterRedisRepository(dataKey);
 
-		updateCount();
-	}
-
-	public void updateCount()
-	{
 		updateCount(_redisRepository.getCount());
 	}
 
-	protected void updateCount(long newCount)
+	public Counter(String dataKey)
 	{
-		_count.set(newCount);
+		this(dataKey, 5000); // 5 seconds
-		_cacheLastUpdated = System.currentTimeMillis();
 	}
 
-	public void increment(long amount)
+	/**
+	 * Add a value to the counter and return the new counter value. This method is thread-safe and interacts
+	 * directly with the atomic value stored in redis. The value returned from redis is then returned
+	 *
+	 * addAndGet will also update the cached counter value so we don't need to make extra trips to redis
+	 *
+	 * @param amount the amount to add to the counter
+	 * @return the updated value of the counter from redis repository
+	 */
+	public long addAndGet(long amount)
 	{
 		long newCount = _redisRepository.incrementCount(amount);
 		updateCount(newCount);
+		return newCount;
 	}
 
+	/**
+	 * Get the latest count of the counter. This will use the last cached value for the counter, or if
+	 * the last cached count hasn't been updated in the {@link #_syncTime} period it will pull the latest
+	 * count from the redis repository and use that value.
+	 *
+	 * @return The counter count
+	 */
 	public long getCount()
 	{
+		if (System.currentTimeMillis() - _lastUpdated > _syncTime)
+		{
+			updateCount(_redisRepository.getCount());
+		}
+
 		return _count.get();
 	}
 
-	public long getGoal()
+	/**
+	 * Reset the counter back to 0. This will take a maximum time of {@link #_syncTime} to propagate
+	 * across all instances of this counter. Immediately updates the redis repository.
+	 *
+	 * @return The value of the counter before it was reset
+	 */
+	public long reset()
 	{
-		return _goal;
+		updateCount(0);
-	}
+		return _redisRepository.reset();
-
-	public double getFillPercent()
-	{
-		return Math.min(1, (((double) getCount()) / _goal));
 	}
 
+	/**
+	 * Get the data key for this counter. The data key is used as the redis repository key
+	 * @return The data key for this counter
+	 */
 	public String getDataKey()
 	{
 		return _dataKey;
 	}
 
-	public long getCacheLastUpdated()
+	/**
+	 * Update the cached count with a new value
+	 * @param newCount updated count
+	 */
+	protected void updateCount(long newCount)
 	{
-		return _cacheLastUpdated;
+		_count.set(newCount);
+		_lastUpdated = System.currentTimeMillis();
 	}
 }

Plugins/Mineplex.ServerData/src/mineplex/serverdata/redis/counter/CounterRedisRepository.java

@@ -42,10 +42,10 @@ public class CounterRedisRepository extends RedisRepository
 	}
 
 	/**
-	 * Increment the current fountain count by {@code increment} and then return the latest
+	 * Increment the current count by {@code increment} and then return the latest
-	 * count of the fountain. This is handled in an atomic process through redis
+	 * count from redis. This is handled in an atomic process
-	 * @param increment Amount to increment the fountain by
+	 * @param increment Amount to increment counter by
-	 * @return The new count for the fountain
+	 * @return The updated count from redis
 	 */
 	public long incrementCount(long increment)
 	{
@@ -59,6 +59,26 @@ public class CounterRedisRepository extends RedisRepository
 		return count;
 	}
 
+	/**
+	 * Reset the counter back to 0
+	 * @return the value of the counter before it was reset
+	 */
+	public long reset()
+	{
+		long count = -1;
+
+		try (Jedis jedis = getResource(true))
+		{
+			count = Long.parseLong(jedis.getSet(getKey(), "0"));
+		}
+
+		return count;
+	}
+
+	/**
+	 * Get the key for this counter
+	 * @return The key is used to store the value in redis
+	 */
 	private String getKey()
 	{
 		return getKey(_dataKey);

Plugins/Mineplex.ServerData/src/mineplex/serverdata/redis/counter/GoalCounter.java

@@ -0,0 +1,101 @@
+package mineplex.serverdata.redis.counter;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A redis counter that is aiming to reach a goal
+ *
+ * @author Shaun Bennett
+ */
+public class GoalCounter extends Counter
+{
+	// Has the goal been completed?
+	private boolean _completed;
+	// The goal we are trying to reach
+	private long _goal;
+
+	private List<GoalCounterListener> _listeners;
+
+	public GoalCounter(String dataKey, long syncTime, long goal)
+	{
+		super(dataKey, syncTime);
+
+		_completed = false;
+		_goal = goal;
+
+		_listeners = new ArrayList<>();
+
+		update();
+	}
+
+	/**
+	 * Get the progress towards the goal as a percent ranging from 0 to 1.
+	 * @return the percent progress towards goal
+	 */
+	public double getFillPercent()
+	{
+		return Math.min(1, (((double) getCount()) / _goal));
+	}
+
+	/**
+	 * Has the goal been completed?
+	 * @return
+	 */
+	public boolean isCompleted()
+	{
+		return _completed;
+	}
+
+	/**
+	 * Get the goal for this GoalCounter
+	 * @return the goal of this counter
+	 */
+	public long getGoal()
+	{
+		return _goal;
+	}
+
+	/**
+	 * Add a listener to this GoalCounter
+	 * @param listener the listener to be added
+	 */
+	public void addListener(GoalCounterListener listener)
+	{
+		_listeners.add(listener);
+	}
+
+	/**
+	 * Clear all the listeners
+	 */
+	public void clearListeners()
+	{
+		_listeners.clear();
+	}
+
+	/**
+	 * Update {@link #_completed} and notify listeners if it has completed
+	 */
+	private void update()
+	{
+		boolean updatedValue = getCount() > _goal;
+
+		if (updatedValue != _completed)
+		{
+			_completed = updatedValue;
+			_listeners.forEach(listener -> {
+				if (_completed) listener.onGoalComplete(this);
+				else            listener.onGoalReset(this);
+			});
+		}
+	}
+
+	@Override
+	protected void updateCount(long newCount)
+	{
+		super.updateCount(newCount);
+
+		update();
+	}
+
+}

Plugins/Mineplex.ServerData/src/mineplex/serverdata/redis/counter/GoalCounterListener.java

@@ -0,0 +1,11 @@
+package mineplex.serverdata.redis.counter;
+
+/**
+ * @author Shaun Bennett
+ */
+public interface GoalCounterListener
+{
+	public void onGoalComplete(GoalCounter counter);
+
+	public void onGoalReset(GoalCounter counter);
+}