libgossip 0.2.1

Python bindings for libgossip - a C++ Gossip protocol implementation

libgossip Python Bindings

This package provides Python bindings for the libgossip C++ library, which implements the Gossip protocol for decentralized distributed systems.

Installation

For regular usage, install the package from PyPI:

pip install libgossip

Then use it in your Python code:

import libgossip
# Use the library

Building from Source

To build the package from source, you need to have CMake and a C++17 compatible compiler installed.

git clone https://github.com/caomengxuan666/libgossip.git
cd libgossip
git submodule update --init
mkdir build
cd build
cmake .. -DBUILD_PYTHON_BINDINGS=ON
cmake --build .

Running Examples

For Users (After Installation)

After installing the package with pip install libgossip, you can run examples from anywhere:

python example.py

For Developers (Using Built Source)

The examples can be run directly from the bindings/python directory after building the project:

# Build the project first (as shown above)
# Then run examples from the bindings/python directory:

# Method 1: Set PYTHONPATH and run directly
set PYTHONPATH=.
python example.py

# Method 2: Run with python -m
python -m libgossip.example

# Method 3: Run examples from within the libgossip package directory
cd libgossip
python sdk_example.py
python decorator_example.py
python advanced_decorator_example.py
cd ..

Note: Examples must be run from the bindings/python directory to work correctly with the built module.

Usage

Low-level API

import libgossip

# Create a node view for ourself
self_node = libgossip.NodeView()
self_node.ip = "127.0.0.1"
self_node.port = 7000
self_node.status = libgossip.NodeStatus.ONLINE

# Define callbacks
def send_callback(msg, target):
    print(f"Sending message of type {msg.type} to {target.ip}:{target.port}")

def event_callback(node, old_status):
    print(f"Node {node.ip}:{node.port} changed from {old_status} to {node.status}")

# Initialize gossip core
core = libgossip.GossipCore(self_node, send_callback, event_callback)

# Meet another node
other_node = libgossip.NodeView()
other_node.ip = "127.0.0.1"
other_node.port = 7001
other_node.status = libgossip.NodeStatus.JOINING

core.meet(other_node)

High-level API

import libgossip

# Create and start a node using the high-level API
with libgossip.create_node("127.0.0.1", 7000) as node:
    # Register handlers using decorators
    @node.on_message
    def log_message(msg, target):
        print(f"[SEND] {msg.type} to {target.ip}:{target.port}")
        
    @node.on_event
    def log_event(node_view, old_status):
        print(f"[EVENT] {node_view.ip}:{node_view.port} changed from {old_status} to {node_view.status}")
        
    # Create another node to meet
    other_node = libgossip.create_node("127.0.0.1", 7001)
    other_node.start()
    
    # Meet the other node
    node.meet(other_node)
    
    # Run gossip protocol for a few ticks
    for i in range(5):
        node.tick()

API Reference

The package provides both low-level and high-level APIs:

Low-level Classes

• GossipCore - Main protocol implementation
• NodeView - Node representation with metadata
• GossipMessage - Message structure for network transport
• NodeId - Node unique identifier
• NodeStatus - Node status enumeration
• MessageType - Message type enumeration
• GossipStats - Statistics about the gossip protocol

High-level Classes

• GossipNode - High-level wrapper for a gossip node
• create_node() - Convenience function to create a GossipNode
• create_cluster() - Convenience function to create a cluster of nodes

Decorators

libgossip provides a rich set of decorators to simplify network programming:

Basic Decorators

• @message_handler - Decorator for message handlers
• @event_handler - Decorator for event handlers
• @node.on_message - Method decorator for message handlers
• @node.on_event - Method decorator for event handlers

Filtering Decorators

• @message_type_filter(*message_types) - Filter message handlers by message type
• @node_status_monitor(*statuses) - Filter event handlers by node status changes

Robustness Decorators

• @retry_on_network_error(max_retries=3, delay=0.1) - Automatically retry network operations on failure
• @circuit_breaker(max_failures=3, timeout=60) - Circuit breaker pattern for network operations
• @with_timeout(timeout=5.0) - Add timeout to network operations

Performance Decorators

• @rate_limit(calls_per_second=1) - Rate limit network operations
• @measure_latency - Measure network operation latency
• @async_network_operation - Run network operations asynchronously

Lifecycle Decorators

• @node_lifecycle(auto_start=True, auto_stop=True) - Automatically manage node lifecycle

Cluster Decorators

• @broadcast_to_cluster(exclude_self=True) - Automatically broadcast messages to all nodes in cluster

Example Usage of Decorators

import libgossip

# Filter messages by type
@libgossip.message_type_filter(libgossip.MessageType.PING, libgossip.MessageType.PONG)
def handle_ping_pong(msg, target):
    print(f"Handling {msg.type} from {target.ip}:{target.port}")

# Monitor specific node status changes
@libgossip.node_status_monitor(libgossip.NodeStatus.ONLINE, libgossip.NodeStatus.FAILED)
def handle_status_change(node, old_status):
    print(f"Node {node.ip}:{node.port} changed from {old_status} to {node.status}")

# Add retry logic to network operations
@libgossip.retry_on_network_error(max_retries=3, delay=0.5)
def robust_send(node, msg, target):
    return node.send_message(msg, target)

# Rate limit operations
@libgossip.rate_limit(calls_per_second=10)
def frequent_operation(node):
    # This will be limited to 10 calls per second
    pass

# Add circuit breaker protection
@libgossip.circuit_breaker(max_failures=5, timeout=30)
def protected_network_call(node, msg, target):
    return node.send_message(msg, target)

# Measure operation latency
@libgossip.measure_latency
def timed_operation(node):
    node.tick()