Files
wickra/bindings/go
kingchenc 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
..

Wickra — Go

CI codecov Go Reference License: MIT OR Apache-2.0

Streaming-first technical indicators for Go, over the Wickra C ABI hub via cgo.

Wickra is a multi-language technical-analysis library with a Rust core and bindings for Python, Node.js and WebAssembly, plus a C ABI for C/C++, C#, Go, Java, R and any other C-capable language. Every indicator is an O(1) streaming state machine, so live trading bots and historical backtests share the exact same implementation. This package is the Go binding; it consumes the C ABI hub through cgo and exposes all 514 streaming-first indicators as idiomatic types.

Install

go get github.com/wickra-lib/wickra/bindings/go

The binding uses cgo, so a C compiler is required, and it links against the prebuilt Wickra C ABI library. Build that library from the workspace and stage it under this package's lib/ directory:

cargo build -p wickra-c --release
cp target/release/libwickra.so    bindings/go/lib/   # Linux
cp target/release/libwickra.dylib bindings/go/lib/   # macOS
cp target/release/wickra.dll      bindings/go/lib/   # Windows (also on PATH at run time)

On Linux and macOS the library path is baked in via rpath; on Windows the DLL must be discoverable at run time (next to the executable or on PATH).

Quick start

package main

import (
	"fmt"

	wickra "github.com/wickra-lib/wickra/bindings/go"
)

func main() {
	// Batch: run an indicator over a whole series (NaN at warmup positions).
	prices := make([]float64, 1000)
	for i := range prices {
		prices[i] = 100.0 + float64(i)*0.1
	}
	sma, _ := wickra.NewSma(20)
	defer sma.Close()
	values := sma.Batch(prices)

	// Streaming: the same indicator, fed tick by tick in O(1).
	rsi, _ := wickra.NewRsi(14)
	defer rsi.Close()
	for _, price := range prices {
		value := rsi.Update(price) // NaN during warmup, no recomputation
		if value > 70 {
			fmt.Println("overbought")
		}
	}
	_ = values
}

Batch(prices) and feeding the same prices through Update() produce identical values — the equivalence is enforced by the test suite. Multi-output indicators (MACD, Bollinger, ADX, …) return (Output, bool), with false while warming up. Every indicator owns a native handle freed by Close(); a finalizer is wired as a backstop, but call Close() (e.g. with defer) to release memory promptly.

Documentation

The full indicator catalogue, guides, quickstarts, and API reference live in the main repository and documentation site:

Wickra ships native bindings for Python, Node.js, WebAssembly and Rust, plus a C ABI hub that any C-capable language (C, C++, C#, Go, Java, R) links against — all exposing the same indicators from the shared, unsafe-forbidden Rust core.

Disclaimer

Wickra is an indicator toolkit, not a trading system. The values it computes are deterministic transforms of the input data — they are not financial advice and do not predict the market. Any use in a live trading context is at your own risk. The library is provided as is, without warranty of any kind.

License

Licensed under either of Apache-2.0 or MIT at your option.