Fix snapshot mapping merge bug #230
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Key Issues
Critical issues include missing null checks for deserialized headers, potential division by zero and overflow errors in calculations, and incorrect conditions for handling overlapping segments, all of which could lead to application crashes or incorrect data processing.
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Just to make sure I understand it correctly BuildStorageOffset corresponds to the data in the file right, which consists of only the changed blocks for that BuildId, so based on BuildStorageOffset you know where to read at that file.
I didn't check the visualizer. Thanks for tests! I think they are really helpful here. Maybe adding tests for BuildStorageOffset would make sense as well.
Yes.
Maybe adding tests for |
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Key Issues
The code lacks validation for a non-zero blockSize, which can lead to division errors and potential crashes. Additionally, it assumes mapping.Length and mapping.Offset are multiples of blockSize, risking incorrect calculations and data loss if this assumption is violated.
| // It is used for debugging and visualization. | ||
| // | ||
| // You can pass maps to visualize different groups of buildIds. | ||
| func Visualize(mappings []*BuildMap, size, blockSize, cols uint64, bottomGroup, topGroup *map[uuid.UUID]struct{}) string { |
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🐛 Possible Bug
The code assumes blockSize is non-zero but there's no validation. A zero blockSize will cause a panic in multiple divisions (size/blockSize, mapping.Length/blockSize, mapping.Offset/blockSize).
| func Visualize(mappings []*BuildMap, size, blockSize, cols uint64, bottomGroup, topGroup *map[uuid.UUID]struct{}) string { | |
| func Visualize(mappings []*BuildMap, size, blockSize, cols uint64, bottomGroup, topGroup *map[uuid.UUID]struct{}) string { | |
| if blockSize == 0 { | |
| return "" | |
| } |
| } | ||
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| for _, mapping := range mappings { | ||
| for block := uint64(0); block < mapping.Length/blockSize; block++ { |
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🐛 Possible Bug
The code assumes mapping.Length and mapping.Offset are multiples of blockSize, which if not true could lead to incorrect block calculations and potential data loss.
| for block := uint64(0); block < mapping.Length/blockSize; block++ { | |
| if mapping.Length%blockSize != 0 || mapping.Offset%blockSize != 0 { | |
| continue | |
| } | |
| for block := uint64(0); block < mapping.Length/blockSize; block++ { |
There is a bug that sometimes happens during the sandbox pause. This PR fixed it. It will also include tests for the merged mapping.
✨
Description by Callstackai
This PR fixes a bug related to snapshot mapping merging during sandbox pause and includes tests for the merged mapping functionality.
Diagrams of code changes
sequenceDiagram participant Client participant HeaderMerger participant Storage participant Validator Client->>HeaderMerger: MergeMappings(baseMapping, diffMapping) Note over HeaderMerger: Process base and diff mappings HeaderMerger->>HeaderMerger: Compare mapping blocks HeaderMerger->>HeaderMerger: Handle overlaps HeaderMerger->>HeaderMerger: Create merged mapping HeaderMerger->>Validator: ValidateMappings(mergedMapping) Note over Validator: Validate:<br/>1. Contiguous blocks<br/>2. Block size multiples<br/>3. Complete coverage alt Validation Success Validator-->>HeaderMerger: Valid HeaderMerger-->>Client: Return merged mappings else Validation Error Validator-->>HeaderMerger: Error HeaderMerger-->>Client: Return error endFiles Changed