Split message cache

[vetss]

We need to add cache for incoming already splitted messages. This cache will contain correlation between a message segement reference_number + source_address + dest_address and a SMSC GW's messageId of a first found message segment.
This value will be then logged into a CDR.
This functionality demands extra processing and must be optional and turned off by default.

[vetss]

Hello @StanislawLeja

The initial fix was done by @StanislawLeja in the PR #251.

I have added the PR + my suggested fix into (and SMSSC GW latest code) https://github.com/vetss/smscgateway/commits/smsc_44_Split_message_cache

My comments for a previous solution:

• checking of removeOldReferenceNumbers() at any segement may waste resources. I added some timer for periodically checking (check my fix)
• your synch code at a new created object splitMessageData that means no synching between different concurrent invocations. I tried to refactor code (check my fix) to concantrate all updated in a single synchronised code segment
• when stopping of SMSC GW we need to remove of MBean (check my fix)

What is till missed:

1. I have not tested, we need to make this step at a live server
2. the functionality must be optional and turned off by default, we need to add CLI / GUI for it
   We may use of CLI templeate for enabling (if no objections)

• smsc set cdr_splitted_message_id true

3. We need to update a manul for new CDR fields and a new CLI / GUI
4. should we have CLI / GUI for RemoveOlderThanXSeconds . Should we add it ?
5. I do not understand why we need SplitMessageCacheStruct class. If it is not needed, better to remove it.