Myra Codec Quickstart

Achieve zero-GC serialization with schema-driven code generation.

Prerequisites

• Java 24+ with preview features enabled
• Gradle 8.5+ or Maven 3.9+

Installation

Add to your build.gradle.kts:

plugins {
    id("express.mvp.myra-codegen") version "0.1.0-SNAPSHOT"
}

dependencies {
    implementation("express.mvp.myra:myra-codec:0.1.0-SNAPSHOT")
}

myraCodegen {
    schemaDir = file("src/main/resources/schemas")
    outputDir = file("build/generated/myra")
}

Define Your Schema

Create src/main/resources/schemas/order.myra.yml:

namespace: com.example.trading
version: 1

types:
  Order:
    fields:
      - name: orderId
        type: int64
      - name: symbol
        type: string
        maxLength: 8
      - name: price
        type: decimal
        precision: 18
        scale: 8
      - name: quantity
        type: int32
      - name: side
        type: enum
        values: [BUY, SELL]
      - name: timestamp
        type: int64

Generate Code

./gradlew generateMyra

This generates:

• OrderBuilder - Flyweight writer for encoding
• OrderFlyweight - Zero-copy reader for decoding

Encode Data

import com.example.trading.OrderBuilder;
import java.lang.foreign.Arena;

try (Arena arena = Arena.ofConfined()) {
    var segment = arena.allocate(256);
    var builder = new OrderBuilder();
    
    int bytesWritten = builder
        .wrap(segment, 0)
        .orderId(12345L)
        .symbol("AAPL")
        .price(150_00000000L)  // Fixed-point decimal
        .quantity(100)
        .side(Side.BUY)
        .timestamp(System.nanoTime())
        .build();
    
    // Send segment over network or write to file
}

Decode Data

import com.example.trading.OrderFlyweight;

var flyweight = new OrderFlyweight();
flyweight.wrap(receivedSegment, offset);

// Zero-copy access - no allocations!
long orderId = flyweight.orderId();
Utf8View symbol = flyweight.symbol();  // Returns view, not String
long price = flyweight.price();
int quantity = flyweight.quantity();

JVM Arguments

java --enable-preview --enable-native-access=ALL-UNNAMED -jar myapp.jar

Next Steps

• Schema Reference - Complete schema syntax
• User Guide - Advanced patterns
• API Reference - Generated code documentation