[Breaking] Use non-delta codec for oneof type #146
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Pull Request Overview
This PR changes the oneof codec to use a non-delta encoding approach, replacing the previous delta-based type encoding with direct type encoding using fixed bit counts. This simplifies the codec implementation and improves performance at the cost of a slight increase in uncompressed size.
- Replaces delta encoding with fixed-width bit encoding for oneof types
- Updates specification to reflect the codec change from delta to direct encoding
- Modifies benchmark scripts to reference the correct branch for comparisons
Reviewed Changes
Copilot reviewed 17 out of 17 changed files in this pull request and generated 10 comments.
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| File | Description |
|---|---|
| stefgen/templates/java/oneofEncoder.java.tmpl | Template for Java oneof encoders - removes delta encoding and adds fixed bit count encoding |
| stefgen/templates/java/oneofDecoder.java.tmpl | Template for Java oneof decoders - removes delta decoding and adds fixed bit count decoding |
| stefgen/templates/go/oneof.go.tmpl | Template for Go oneof encoder/decoder - removes delta encoding/decoding and adds fixed bit count approach |
| stef-spec/specification.md | Updates specification to document the change from delta to direct type encoding |
| Multiple generated Java files | Generated code implementing the new non-delta codec for various oneof types |
| Multiple generated Go files | Generated code implementing the new non-delta codec for various oneof types |
| benchmarks/scripts/genoldtestfiles.sh | Updates base branch reference for benchmark comparisons |
| .github/workflows/benchmark.yml | Adds test file generation step to benchmark workflow |
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java/src/main/java/com/example/oteltef/ExemplarValueDecoder.java
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Resolves #127 This simplifies oneof codec and improves codec speed at the cost of slight increase of uncompressed size. The zstd-compressed size is approximately the same (slightly increased or decresed depending on the dataset). ### Benchmarks Otel schema speed improvement: ``` │ bench_base.txt │ bench_current.txt │ │ sec/point │ sec/point vs base │ SerializeNative/STEF/serialize-10 64.36n ± 1% 63.10n ± 2% -1.96% (p=0.020 n=9) DeserializeNative/STEF/deser-10 24.06n ± 1% 22.70n ± 1% -5.65% (p=0.000 n=9) geomean 39.35n 37.85n -3.82% ``` Otel schema size before the change: ``` File Uncompressed Zstd Bytes hipstershop-otelmetrics.stefz 432716 93702 hostandcollector-otelmetrics.stefz 1258652 83009 astronomy-otelmetrics.stefz 7462303 1652082 ``` After the change: ``` File Uncompressed Zstd Bytes hipstershop-otelmetrics.stefz 441558 95083 hostandcollector-otelmetrics.stefz 1266627 79835 astronomy-otelmetrics.stefz 7557122 1644464 ```
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maheshkanote
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Resolves #127
This simplifies oneof codec and improves codec speed at the cost of slight increase
of uncompressed size. The zstd-compressed size is approximately the same (slightly
increased or decresed depending on the dataset).
Benchmarks
Otel schema speed improvement:
Otel schema size before the change:
After the change:
Other benchmarks show similar patterns for speed and size changes.