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wickra/.github/PULL_REQUEST_TEMPLATE/detailed.md
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kingchencandGitHub 167f7b3ffe Add the Java binding over the C ABI hub (Panama/FFM) (#233)
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.
2026-06-09 20:30:29 +02:00

2.2 KiB

Summary

Type of change

  • Bug fix (Non-breaking change which fixes an issue)
  • New feature (Non-breaking change which adds functionality)
  • Breaking change (Fix or feature that changes existing public API)
  • Performance improvement
  • Refactor (No functional change)
  • Documentation only
  • CI / build / tooling

Affected surfaces

  • Rust crate (crates/wickra)
  • Python binding (bindings/python)
  • Node.js binding (bindings/node)
  • WebAssembly binding (bindings/wasm)
  • C ABI (bindings/c)
  • C# / .NET binding (bindings/csharp)
  • Go binding (bindings/go)
  • Java binding (bindings/java)
  • R binding (bindings/r)
  • Examples / docs

Linked issues

Closes #

How was this tested?

Numerical correctness (If you touched an indicator)

  • Output matches an existing reference (TA-Lib, paper, prior Wickra release) within documented tolerance
  • Streaming update() matches batch / from_slice output on the same input
  • Edge cases covered: empty input, single point, NaN, leading warm-up window

Performance impact (If applicable)

Benchmark Before After Δ

Checklist

  • cargo fmt --all and cargo clippy --all-targets -- -D warnings are clean
  • cargo test --workspace passes locally
  • Binding tests run (If a binding changed)
  • Public API changes are reflected in CHANGELOG.md
  • Public API changes are reflected in rustdoc / README / examples
  • No todo*.md or other local-only notes are staged
  • License header / LICENSE reference unchanged (MIT OR Apache-2.0)

Notes for reviewers