Merge pull request osheroff#2 from osheroff/ben/lru_cache

prevent TableMapEventData hash from growing unbounded.

Author: osheroff

src/main/java/com/github/shyiko/mysql/binlog/event/LRUCache.java

@@ -0,0 +1,19 @@
+package com.github.shyiko.mysql.binlog.event;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+public class LRUCache<K,V> extends LinkedHashMap<K,V> {
+    private int maxSize;
+
+    // and other constructors for load factor and hashtable capacity
+    public LRUCache(int initialCapacity, float loadFactor, int maxSize) {
+        super(initialCapacity, loadFactor, true);
+        this.maxSize = maxSize;
+    }
+
+    @Override
+    protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
+        return size() > maxSize;
+    }
+}

src/main/java/com/github/shyiko/mysql/binlog/event/deserialization/EventDeserializer.java

@@ -20,6 +20,7 @@
 import com.github.shyiko.mysql.binlog.event.EventHeader;
 import com.github.shyiko.mysql.binlog.event.EventType;
 import com.github.shyiko.mysql.binlog.event.FormatDescriptionEventData;
+import com.github.shyiko.mysql.binlog.event.LRUCache;
 import com.github.shyiko.mysql.binlog.event.TableMapEventData;
 import com.github.shyiko.mysql.binlog.io.ByteArrayInputStream;
 
@@ -65,7 +66,7 @@ public EventDeserializer(
         this.eventHeaderDeserializer = eventHeaderDeserializer;
         this.defaultEventDataDeserializer = defaultEventDataDeserializer;
         this.eventDataDeserializers = new IdentityHashMap<EventType, EventDataDeserializer>();
-        this.tableMapEventByTableId = new HashMap<Long, TableMapEventData>();
+        this.tableMapEventByTableId = new LRUCache<>(100, 0.75f, 10000);
         registerDefaultEventDataDeserializers();
         afterEventDataDeserializerSet(null);
     }