kingchencandGitHub
167f7b3ffe
Adds a Java binding (`bindings/java`) over the C ABI hub — the fourth language stecker after C#, Go and R, reaching the hub through the Java Foreign Function & Memory API (Panama, `java.lang.foreign`, final in Java 22) rather than JNI or jextract. ## What's here - **`bindings/java`** — a Maven module (`org.wickra:wickra`) exposing all 514 indicators as idiomatic `AutoCloseable` classes. The downcall handles (`internal/NativeMethods.java`), the per-indicator wrappers and the output records are generated from `bindings/c/include/wickra.h` (same eight-archetype taxonomy as the C#/Go/R generators: scalar/batch, multi-output, bars, profile, values-profile, array-input). The opaque handle is a `MemorySegment` freed by a registered `java.lang.ref.Cleaner` action; multi-output returns a `record` (`null` at warmup), bars a `record[]`, profiles a record with a trailing `double[]`. The hand-written `WickraNative` resolves the native library (a bundled per-platform copy, or a `target/release` fallback for local development) and validates it against a sentinel symbol. repr(C) struct offsets are computed in the generator so the FFM reads land on the exact bytes. - **`examples/java`** — the full example suite mirroring C/C#/Go/R: streaming, backtest, multi_timeframe, parallel_assets (parallel streams), three strategies, and `FetchBtcusdt`/`LiveBinance`. - **CI** — a `java` job builds the C ABI library, sets up JDK 22 (Temurin, with a CDN-flake retry), runs the archetype test suite and the seven offline examples on Linux, macOS and Windows. - **Release** — a gated `java-publish` job (skipped until the `JAVA_PUBLISH_ENABLED` repository variable is set) stages the native libraries from the `wickra-c-<triple>.tar.gz` assets into the binding's resources and deploys to Maven Central with GPG signing. Independent of the GitHub-release job, like the NuGet job. - **Docs** — Java added to the README languages table, project layout, building/testing and comparison table, CONTRIBUTING, ARCHITECTURE, the examples index, the issue/PR templates, the About-description template, and the other binding READMEs. ## Requirements Java 22+ (the FFM API is final since Java 22). The binding requires `--enable-native-access=ALL-UNNAMED` at runtime; the test and example runners pass it automatically. No Rust crate or `Cargo.toml` change — the Java binding is standalone and additive. The generated `*.java` are committed (like the node `index.js`/`index.d.ts`); the generator stays private.
55 lines
1.6 KiB
Markdown
55 lines
1.6 KiB
Markdown
---
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name: Performance regression
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about: Report a measurable slowdown, memory blowup, or throughput drop.
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title: "[Perf] <indicator / API> regressed in <version>"
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labels: ["performance", "regression", "triage"]
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assignees: []
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---
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## Summary
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<!-- Which code path got slower, by how much, and since when? -->
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## Affected code path
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- Indicator / API: `e.g. EMA.update`
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- Binding: `Rust / Python / Node / Wasm / C ABI / C# (.NET) / Go / Java / R`
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- Hot loop or one-shot call?
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## Versions compared
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| Version | Throughput / latency / memory | Notes |
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| -------- | ----------------------------- | ----- |
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| `0.4.1` | `e.g. 12.3 ns/iter` | baseline (Good) |
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| `0.4.2` | `e.g. 38.7 ns/iter` | regressed |
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## Benchmark / reproducer
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<!--
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Paste the criterion / pytest-benchmark / hyperfine command and its output.
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For one-off measurements, include the timing snippet inline.
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-->
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```bash
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cargo bench --bench ema -- --save-baseline new
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```
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```
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ema/update time: [38.5 ns 38.7 ns 38.9 ns]
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change: [+213.4% +214.8% +216.1%] (p = 0.00 < 0.05)
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Performance has regressed.
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```
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## Hardware / environment
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| Field | Value |
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| ------------ | -------------------------------------- |
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| CPU | `e.g. Ryzen 9 9950X, AVX2 + AVX512` |
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| OS / arch | `e.g. Linux 6.8 x86_64` |
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| Toolchain | `rustc 1.x.y` |
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| Build flags | `RUSTFLAGS=...`, `--release`, profile |
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## Suspected cause
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<!-- Optional. Link the commit / PR if you've bisected it. -->
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