kingchenc
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.
1.6 KiB
1.6 KiB
name, about, title, labels, assignees
| name | about | title | labels | assignees | |||
|---|---|---|---|---|---|---|---|
| Performance regression | Report a measurable slowdown, memory blowup, or throughput drop. | [Perf] <indicator / API> regressed in <version> |
|
Summary
Affected code path
- Indicator / API:
e.g. EMA.update - Binding:
Rust / Python / Node / Wasm / C ABI / C# (.NET) / Go / Java / R - Hot loop or one-shot call?
Versions compared
| Version | Throughput / latency / memory | Notes |
|---|---|---|
0.4.1 |
e.g. 12.3 ns/iter |
baseline (Good) |
0.4.2 |
e.g. 38.7 ns/iter |
regressed |
Benchmark / reproducer
cargo bench --bench ema -- --save-baseline new
ema/update time: [38.5 ns 38.7 ns 38.9 ns]
change: [+213.4% +214.8% +216.1%] (p = 0.00 < 0.05)
Performance has regressed.
Hardware / environment
| Field | Value |
|---|---|
| CPU | e.g. Ryzen 9 9950X, AVX2 + AVX512 |
| OS / arch | e.g. Linux 6.8 x86_64 |
| Toolchain | rustc 1.x.y |
| Build flags | RUSTFLAGS=..., --release, profile |