CPS-1034 Publish LCM Events on Cmhandle State Change

CPS-1034 - Getting issue details... STATUS

Implementation Proposal

Problem Statement :  

To publish the NcmpEvent when there is a change in the cmHandleState ( state transition )

Scenarios to keep in mind

• We have to introduce a detail field in the NcmpEvent payload which can contain the previous state and other details.
• We have to publish an event on public properties update ( even though we dont have any state change ???? ) 

Potential Solutions

1. Use code triggers
2. Any other solution ? Common State Handler

Solution #1 : Code Triggers

• Identify all the possible cm handle state transitions.
  
  

• Create a cmHandleState handler which takes in the cmHandleState transition event
  --  Responsible for identifying the state transition
  --  Based on state transition call the relevant methods to create the NcmpEvent accordingly.
  
  
  
• Identify the trigger points in the code where the actual state transitioning is happening and call the handler from there and provide the type of transition.
  
  
  Overview

2. Solution #2

Responsibilities of the state handlers

• Accept : cmHandleId and other common params.
• Set the object to the required state.
• Persist the new state.
• Send the correct event about the state change.

• Identify the input and output params.
  I/P : examine the existing code , identify the commonalities and then propose.

Current State Transition:

1. Create Registration (NEW to ADVISED)
2. Module Sync Success ( ADVISED TO READY)
   Fail (ADVISED TO LOCKED)
3. Retry ( LOCKED TO ADVISED ) 
4. Deleting ( ADVISED to DELETING , READY to DELETING, LOCKED to DELETING )  / separate us **
5. Deleted ( DELETING to DELETED )  separate us **   CPS-1120 - Getting issue details... STATUS

At a high level the method signature should like below.

    /**
     * Responsible for handling the state transition and publishing the lcm event if required.
     *
     * @param cmHandleId          cm handle id
     * @param yangModelCmHandle   cm handle represented as Yang Model
     * @param targetCmHandleState target cm handle state
     */
    void updateState(final String cmHandleId, final YangModelCmHandle yangModelCmHandle,
            final CmHandleState targetCmHandleState);

References : 

CPS-799 Spike: Define states and state handling for CM handle

CPS-858 Define Notifications on CM Handle Add (Ready) & Delete