Callosum

An RPC Transport Library

It provides an asynchronous multi-channel order-preserving message and data streaming transport for upper RPC layers (e.g., Apache Thrift) by wrapping lower transport implementations (e.g., ZeroMQ).

It aims to follow the latest coding style and conventions in Python asyncio.

Corpus callosum is a bundle of neuron fibers that connects two cerebral hemispheres of a human brain.

Prerequisite

Python 3.11 or higher.

Features

• RPC
  • Native timeout and cancellation support
  • Explicit server-to-client error propagation including stringified tracebacks
  • Order preserving based on user-defined keys while keeping executions asynchronous
• Streaming
  • Broadcast & shared pipelines
• Optional client authentication and encrypted communication
  • Currently supported for only ZeroMQ with its CURVE library
• Optional message compression using snappy
• Replacible and combinable lower/upper layers (ZeroMQ/Redis + JSON/msgpack/Thrift)

Planned features

• Managed streaming (with acks)
• Tunneling to bundle other channels and generic network traffic in a single connection
• Bidirectional RPC
• Chunked transfer of large messages

Installation

To install the core:

$ pip install -U pip setuptools
$ pip install callosum

You may add extra dependencies like:

$ pip install 'callosum[zeromq,redis,thrift,snappy]'

Examples

Please check out the examples directory.

Development

Create a virtual environment or an isolated Python environment using your favorite tool.

Inside it, run editable installation as follows:

$ pip install -U pip setuptools
$ pip install -U -r requirements/dev.txt