Use explicit stack in DouglasPeuckerLineSimplifier (#1127)#1216
Open
grootstebozewolf wants to merge 1 commit into
Open
Use explicit stack in DouglasPeuckerLineSimplifier (#1127)#1216grootstebozewolf wants to merge 1 commit into
grootstebozewolf wants to merge 1 commit into
Conversation
Recursive simplifySection can throw StackOverflowError on long, highly oscillatory linework where each split peels one vertex (depth O(n)). Rewrite as an iterative pair-stack, preserving left-then-right split order and results. Add a zig-zag regression test that forces deep unbalanced splits.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
StackOverflowErrorinDouglasPeuckerLineSimplifier.simplifySectionon long, highly oscillatory linework where each split peels one vertex (recursion depth O(n)), as reported in DouglasPeuckerLineSimplifier.simplifySection() recursive calls cause StackOverflowError #1127.Risk / approach
A max-depth bail-out would change results. An explicit stack matches the maintainer suggestion on #1127 and keeps algorithm semantics while bounding memory by the heap rather than the JVM call stack.
Test plan
mvn -pl modules/core test -Dtest=DouglasPeuckerSimplifierTest— 21 tests, 0 failures (includes new SOE case)TopologyPreservingSimplifierTest+VWSimplifierTest— 38 tests, 0 failures-Xssif maintainers want a hard recursive SOE repro for comparisonFixes #1127