Optimize findViewByNodeId with an O(1) view map (m.__router_viewMap)

[iObject]

Optimize findViewByNodeId with an O(1) view map (m.__router_viewMap)

Problem

findViewByNodeId previously iterated over all children of viewTarget and keepAliveViewTarget to find a view by node ID. This is O(n) in the stack depth and is called on every goBack and popToCheckpoint.

Proposal

Introduce m.__router_viewMap — an associative array keyed by node ID that tracks every live view and whether it currently lives in viewTarget or keepAliveViewTarget.

findViewByNodeId now does a single AA lookup instead of looping over node children.

Map maintenance

The map is kept in sync at every point where a view changes ID, location, or lifetime:

Event	Action
View added to viewTarget in addViewToStack	viewMap[id] = { ..., fromKeepAlive: false }
View suspended to keepAliveViewTarget (forward nav or suspendView)	viewMap[id] = { ..., fromKeepAlive: true }
keepAlive view ID reassigned on reuse in addViewToStack	viewMap.delete(old id) before reassign
View reparented back to viewTarget (_goBack, _popToCheckpoint)	viewMap[id] = { ..., fromKeepAlive: false }
View destroyed in closeView	viewMap.delete(id)
View destroyed inline in addViewToStack (non-keepAlive close loop)	viewMap.delete(id)
Router destroyed in _destroy	m.__router_viewMap = {}

Impact

• findViewByNodeId is now O(1) regardless of stack depth.
• No change to observable behaviour — the map mirrors the existing node-tree structure exactly.