KREN

Zero-Copy Shared Memory IPC

KREN is a fast, cross-language Inter-Process Communication (IPC) library written in Rust. It does not use OS networking like TCP or HTTP and avoids serialization like JSON or Protobuf. Instead, it creates a direct shared memory link between processes.

Features

• Zero-Copy Transfers: Data is written once and read directly.
• Low Latency: 102ns for 64B messages measured.
• Lock-Free: Uses a Single-Producer Single-Consumer ring buffer with atomic synchronization.
• Cross-Language: Native bindings for Python and Node.js.
• Battle-Tested: Passes stress tests and 100K message validation.
• Windows: Uses Named File Mappings (CreateFileMappingW).
• Linux and macOS: Uses POSIX shared memory (shm_open and mmap).

Installation

Rust

Add this to your Cargo.toml:

[dependencies]
kren-core = "0.1"

Python

pip install kren

Node.js

npm install @pawanxz/kren

Quick Start

Python to Node.js Communication

writer.py

import kren

writer = kren.Writer("my_channel", 1024 * 1024)
writer.write(b"Hello from Python!")
print(f"Written. Available space: {writer.available}")

reader.js

const kren = require('@pawanxz/kren');

const reader = new kren.Reader("my_channel");
const data = reader.read();
console.log(`Received: ${data.toString()}`);

Rust Usage

use kren_core::{KrenWriter, KrenReader};

// Process A
let mut writer = KrenWriter::create("my_channel", 4096).unwrap();
writer.write(b"Hello, World!").unwrap();

// Process B
let mut reader = KrenReader::connect("my_channel").unwrap();
let data = reader.read().unwrap();
assert_eq!(data, b"Hello, World!");

Architecture

Process A (like Python) and Process B (like Node.js) talk through a shared memory segment. KrenWriter writes data to the memory. KrenReader reads data from the memory. They use a ring buffer managed by atomic head and tail pointers.

Performance (Measured)

Message Size	Latency	Throughput
64 bytes	102 ns	9.7M ops/sec
1 KB	189 ns	5.2M ops/sec
64 KB	5.6 μs	11 GB/s

Benchmarks were measured on Windows with Rust 1.93 in release mode. Run cargo test --release --test bench -- --nocapture to reproduce.

API Reference

Writer

Method	Description
Writer(name, capacity)	Create a new channel
write(data)	Write bytes to the channel
available	Free space in bytes
name	Channel identifier

Reader

Method	Description
Reader(name)	Connect to existing channel
read()	Read next message
tryRead() (JS) / try_read()	Non-blocking read, returns None or null if empty
writerClosed (JS) / writer_closed	Check if writer disconnected
available	Data available in bytes
name	Channel identifier

Building from Source

git clone https://github.com/Cintu07/kren
cd kren

# Build and test core library
cargo build --release
cargo test

# Build Python bindings
cd kren-python
maturin develop
pytest

# Build Node.js bindings
cd kren-node
npm run build
npm test

License

MIT License. See LICENSE for details.