engineering/java-topology
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
java-topology/defects/dgraph/patch/dgraph-diamond-recursion-CLEAN.md
russell@unturf.com 1dee074618 kafka-0009: GraphGraceSearchUtil diamond recursion O(2^D) → O(N); count 621→622 
findAndVerifyWindowGrace() recurses over parent GraphNodes without a visited
accumulator. Kafka Streams GraphNode is a genuine DAG (addChild wires
parent→child with multiple parents allowed), so a diamond topology causes
2^D recursive calls. Fix: thread an IdentityHashMap<GraphNode,Long> memo
through recursion; memoize on first visit, return cached result on revisit.
8/8 unit tests PASS; D=10 defect count=3071 vs patched O(N).

Diamond-recursion CLEAN markers added for: flink, neo4j, janusgraph,
tinkerpop, dgraph, zookeeper, storm, ant, gradle, graal, eclipse-jdt,
exposed, intellij, kotlin, scala3, hibernate-0007 (prior session work
now committed).
2026-03-29 16:59:50 -04:00

639 B
Raw Blame History

dgraph — diamond recursion CWE-407 scan: CLEAN

Scan date: 2026-03-29

Method scanned

SubGraph.recurse() in query/query.go — recursive SubGraph traversal.

Finding

SubGraph.Children and SubGraph.Filters are []*SubGraph slices. Each SubGraph is created from a DQL parse tree where each child has a unique parent. The structure is a tree (parse tree), not a DAG. A single SubGraph node cannot appear as a child of two different parents, so diamond blowup is not possible.

The existing dgraph-0001 (shortest-path route indexOf) was already filed. No new diamond recursion patterns were found.

Verdict: CLEAN