tree cb4652e78943d2f1623597ce328dabbda08baa30
parent d0d0c5fa8652ee6232f93b133db61d1456034cb2
author janakr <janakr@google.com> 1628094654 -0700
committer Copybara-Service <copybara-worker@google.com> 1628094739 -0700

Optimize some parts of Skyframe node deletion, especially for the case of discarding the analysis cache on a configuration change:

1. Avoid processing to-be-deleted direct deps of a node being deleted: removing this node from the dep's reverse deps is useful only as a consistency check and is too expensive to justify, given that it's been a long time since there was a bug there.

2. To make (1) more effective, in an analysis-cache-discarding event, eagerly mark all ActionLookupData nodes as to-be-deleted: they will be deleted anyway, since they depend on ActionLookupKey nodes, and marking them eagerly means we can apply the optimization in (1).

3. Don't make an ImmutableSet copy of the reverse deps in ReverseDepsUtility#getReverseDeps when the node is about to be deleted: the consistency check is not worth the cost.

This should reduce CPU, memory churn, and contention.

PiperOrigin-RevId: 388715102