Package com.dna.jopt.member.bucket.route.controller.loadcontroller

Class LoadController

java.lang.Object

com.dna.jopt.member.bucket.route.controller.loadcontroller.LoadController

All Implemented Interfaces:

ILoadController, Serializable

public class LoadController
extends Object
implements ILoadController

Manages the dynamic per-node INodeDepot state for one entity.

Design — flat one-level COW with on-demand deep isolation

Every instance has two fields:

• ownMap — this instance's private depot writes. Always a ConcurrentHashMap. The assessor writes here via putFlexLoadNodeDepot(java.lang.String, com.dna.jopt.member.unit.pnd.depot.node.INodeDepot).
• parentMap — a reference to the parent's complete ownMap at the moment partialCopy() was called. Non-null only in COW copies. Never modified after construction.

Performance

partialCopy() is O(1): it passes this.ownMap by reference as the child's parentMap and allocates a fresh empty ownMap for the child. No depot copying happens at clone time. Copying is deferred to getFlexLoadNodeDepot(java.lang.String): only the specific depot that an operator actually touches is deep-copied at the moment it is first accessed on the clone.

Correctness — why deep copy in lazy isolation

Lazy isolation calls INodeDepot.copy() (deep — ILoad.copy() per item), not partialCopy() (shallow — shared ILoad references). This is essential: FlexLoadOperator calls setLoad() directly on an ILoad object that is already inside the depot's item list. A shallow copy would leave that object shared between the clone and the parent, so mutations on the clone would corrupt the parent's depot state. A deep copy gives the clone fully independent ILoad objects.

Thread safety

Both maps are ConcurrentHashMap instances. get and put are safe under concurrent assessor threads. parentMap is never modified after construction, so reads are always safe. ownMap is iterated with a weakly-consistent iterator in partialCopy() — never throws CME.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
LoadController()	Creates a standalone instance with an empty depot map.

Method Summary

Modifier and Type	Method	Description
ILoadController	copy()
void	flatten()	Promotes this COW copy to a standalone instance by merging parentMap into ownMap and clearing the parent reference.
Optional<INodeDepot>	getFlexLoadNodeDepot(String nodeId)	Returns the depot for nodeId.
Map<String,INodeDepot>	getNodeDepotMap()	Returns a merged view of this instance's map and all ancestors.
ILoadController	partialCopy()	Creates a COW child in O(1).
boolean	putFlexLoadNodeDepot(String nodeId, INodeDepot depot)
void	setNodeDepotMap(Map<String,INodeDepot> m)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

LoadController

public LoadController()

Creates a standalone instance with an empty depot map.

Method Details

getNodeDepotMap

public Map<String,INodeDepot> getNodeDepotMap()

Description copied from interface: ILoadController

Returns a merged view of this instance's map and all ancestors.

Not on the hot path — used by result-extraction code that needs a complete snapshot. For hot-path reads, use ILoadController.getFlexLoadNodeDepot(java.lang.String) directly.

Specified by:

getNodeDepotMap in interface ILoadController

setNodeDepotMap

public void setNodeDepotMap(Map<String,INodeDepot> m)

Specified by:

setNodeDepotMap in interface ILoadController

putFlexLoadNodeDepot

public boolean putFlexLoadNodeDepot(String nodeId,
 INodeDepot depot)

Specified by:

putFlexLoadNodeDepot in interface ILoadController

getFlexLoadNodeDepot

public Optional<INodeDepot> getFlexLoadNodeDepot(String nodeId)

Returns the depot for nodeId.

Checks ownMap first (O(1)). On miss, checks parentMap and lazily isolates the depot into ownMap via a deep copy (INodeDepot.copy()) so that the clone owns fully independent ILoad objects. Subsequent accesses for the same node hit ownMap directly (O(1)).

Specified by:

getFlexLoadNodeDepot in interface ILoadController

partialCopy

public ILoadController partialCopy()

Creates a COW child in O(1).

this.ownMap is passed by reference as the child's parentMap. The child gets a fresh empty ownMap. No depots are copied at this point — copying is deferred to the first getFlexLoadNodeDepot(java.lang.String) call that misses ownMap.

If this instance is itself a COW copy (parentMap != null), the complete visible state (parent + own entries, own wins) is merged into a snapshot first so the child always sees the full picture.

Specified by:

partialCopy in interface ILoadController

copy

public ILoadController copy()

Specified by:

copy in interface ILoadController

flatten

public void flatten()

Promotes this COW copy to a standalone instance by merging parentMap into ownMap and clearing the parent reference.

Optional but beneficial: makes the next partialCopy() O(1) (Case 1) instead of requiring a merge step (Case 2).