Feature request or enhancement

Memory leak in EventDeserializer caused by tableMapEventByTableId

Related:

https://github.com/osheroff/mysql-binlog-connector-java/issues/62

https://github.com/osheroff/mysql-binlog-connector-java/pull/2/files

Table id is not a constant value in one MySQL instance, it will assign a new id when there is no cached table id found, or roll to a new id when the cache in MySQL server `my_hash_search_using_hash_value` {}is full. Thus, it is not necessary keeping this tableMapEventByTableId map all the time.

MySqlStreamingChangeEventSource:224

// Set up the event deserializer with additional type(s) ...
final Map<Long, TableMapEventData> tableMapEventByTableId = new HashMap<Long, TableMapEventData>(); 

We override the EventDeserializer and use HashMap to store the TableMapData here.

Assume that the MySQL server's `table_def_cache` size is 400 and we have over 400 tables keep writing, the same table's table id may be increased over time and the tableMapEventByTableId will become unbounded.

Implementation ideas (optional)

Clear it on ROTATE event

Or use LRUCache instead of HashMap (Not safe in extreme cases)