russell@unturf.com
1dee074618
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).
20 lines
661 B
Markdown
20 lines
661 B
Markdown
# zookeeper — diamond recursion CWE-407 scan: CLEAN
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## Scan date: 2026-03-29
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## Method scanned
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`SnapshotRecursiveSummary.printZnode()` — recursive ZNode tree walk.
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## Finding
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ZooKeeper's data model is a strict hierarchical namespace (a tree, not a DAG). A
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ZNode path is unique; no ZNode can appear under two different parent paths.
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`DataNode.children` is a `Set<String>` of relative child names, and `DataTree` is
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keyed by full path (`ConcurrentHashMap<String, DataNode>`). Diamond topology is
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impossible by construction.
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`printZnode` recursion is therefore O(N) where N is the number of ZNodes, with no
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risk of exponential blowup.
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## Verdict: CLEAN
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