fix non-deterministic piece CID for inline DAG regeneration#657
Merged
Conversation
UnmarshalToBlocks iterated data.Reals and data.Additional via 'for c, d := range', and Go map iteration order is randomized per-instance. The same serialized directory blob therefore yielded a different block sequence on each call, producing a different CAR byte layout and a different piece CID even though the root CID was stable. Sort the CIDs lexicographically before iterating so the CAR layout is content-derived and reproducible. Add a regression test that asserts the same marshaled blob unmarshals to the same block order across repeated calls. Reported by users seeing baga6ea4...drift across consecutive 'dag generate' runs against the same inline preparation.
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
UnmarshalToBlocks iterated data.Reals and data.Additional via 'for c, d := range', and Go map iteration order is randomized per-instance. The same serialized directory blob therefore yielded a different block sequence on each call, producing a different CAR byte layout and a different piece CID even though the root CID was stable.
Sort the CIDs lexicographically before iterating so the CAR layout is content-derived and reproducible. Add a regression test that asserts the same marshaled blob unmarshals to the same block order across repeated calls.
Reported by users seeing baga6ea4...drift across consecutive 'dag generate' runs against the same inline preparation.