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name: pywayne-cross-comm description: WebSocket-based cross-language communication service with support for multiple message types (text, JSON, dict, bytes, images, files, folders) and client management. Use when building real-time communication applications between Python and other languages, needing multi-device messaging, or requiring file transfer via Aliyun OSS. Supports both server and client roles with heartbeat, client list management, and message filtering by type or sender.

Pywayne Cross Comm

pywayne.cross_comm.CrossCommService provides WebSocket-based real-time communication between Python and other languages, with built-in file transfer via Aliyun OSS.

Prerequisites

OSS Configuration (required for file/image/folder transfer):

File transfers use Aliyun OSS. Set these environment variables:

# .env file
OSS_ENDPOINT=your-oss-endpoint
OSS_BUCKET_NAME=your-bucket-name
OSS_ACCESS_KEY_ID=your-access-key
OSS_ACCESS_KEY_SECRET=your-access-secret

For more OSS details, see pywayne-aliyun-oss skill.

Quick Start

import asyncio
from pywayne.cross_comm import CrossCommService, CommMsgType

# Server
server = CrossCommService(role='server', ip='0.0.0.0', port=9898)
await server.start_server()

# Client
client = CrossCommService(role='client', ip='localhost', port=9898, client_id='my_client')
await client.login()

Server

Initialize server

server = CrossCommService(
    role='server',
    ip='0.0.0.0',        # Listen on all interfaces
    port=9898,
    heartbeat_interval=30,     # Seconds between heartbeats
    heartbeat_timeout=60       # Seconds before marking offline
)

Register message listeners

@server.message_listener(msg_type=CommMsgType.TEXT)
async def handle_text(message):
    print(f"From {message.from_client_id}: {message.content}")

@server.message_listener(msg_type=CommMsgType.FILE, download_directory="./downloads")
async def handle_file(message):
    print(f"File downloaded: {message.content}")

Start server

await server.start_server()  # Blocks until server stops

Get online clients

online_clients = server.get_online_clients()  # Returns list of client IDs

Client

Initialize client

client = CrossCommService(
    role='client',
    ip='localhost',           # Server address
    port=9898,
    client_id='my_client',    # Optional: auto-generated if omitted
    heartbeat_interval=30,
    heartbeat_timeout=60
)

Login and logout

success = await client.login()
if success:
    print("Connected!")
    # ... communicate ...
    await client.logout()

Send messages

# Broadcast to all
await client.send_message("Hello!", CommMsgType.TEXT)

# Send to specific client
await client.send_message("Private", CommMsgType.TEXT, to_client_id='target_id')

# JSON message
await client.send_message('{"key": "value"}', CommMsgType.JSON)

# Dict message
await client.send_message({"type": "data", "value": 123}, CommMsgType.DICT)

# Bytes (auto base64 encoded)
await client.send_message(b"binary", CommMsgType.BYTES)

# File (auto uploads to OSS)
await client.send_message("/path/to/file.txt", CommMsgType.FILE)

# Image (auto uploads to OSS)
await client.send_message("/path/to/image.jpg", CommMsgType.IMAGE)

# Folder (auto uploads to OSS)
await client.send_message("/path/to/folder", CommMsgType.FOLDER)

Get client list

# All clients (online + offline)
all_clients = await client.list_clients(only_show_online=False)
# Returns: {'clients': [...], 'total_count': N, 'only_show_online': False}

# Online only
online = await client.list_clients(only_show_online=True)

Message Types

CommMsgType enum (use these, not strings):

Type	Description
CommMsgType.TEXT	Plain text
CommMsgType.JSON	JSON string
CommMsgType.DICT	Python dict
CommMsgType.BYTES	Binary data
CommMsgType.IMAGE	Image file
CommMsgType.FILE	Regular file
CommMsgType.FOLDER	Folder

Internal types (auto-handled): HEARTBEAT, LOGIN, LOGOUT, LIST_CLIENTS, LIST_CLIENTS_RESPONSE, LOGIN_RESPONSE

Message Listener Decorator

# Listen to specific type
@service.message_listener(msg_type=CommMsgType.TEXT)
async def handler(message):
    pass

# Listen from specific sender
@service.message_listener(msg_type=CommMsgType.FILE, from_client_id='specific_client')
async def handler(message):
    pass

# Listen to all types
@service.message_listener()
async def handler(message):
    pass

Note: Listeners automatically filter out messages sent by yourself.

File Download Control

File downloads are controlled via the listener's download_directory parameter:

# Auto-download files to ./downloads
@client.message_listener(msg_type=CommMsgType.FILE, download_directory="./downloads")
async def handle_file(message):
    # message.content contains downloaded file path
    print(f"Downloaded: {message.content}")

# No auto-download - saves bandwidth
@client.message_listener(msg_type=CommMsgType.FILE, from_client_id='low_priority')
async def handle_file(message):
    # message.content contains OSS key, not downloaded
    print(f"File available: {message.oss_key}")
    # Optionally: client.download_file_manually(message.oss_key, "./manual_downloads/")

Manual download

success = client.download_file_manually(
    oss_key="cross_comm/sender_id/123456_file.txt",
    save_directory="./downloads"
)

Message Object

@dataclass
class Message:
    msg_id: str                    # Unique message ID
    from_client_id: str            # Sender ID
    to_client_id: str              # 'all' or specific client ID
    msg_type: CommMsgType           # Message type enum
    content: Any                   # Message content
    timestamp: float                # Unix timestamp
    oss_key: Optional[str]         # OSS key for file transfers

    def to_dict(self) -> Dict:      # Convert to dict
    @classmethod
    def from_dict(cls, data) -> 'Message':  # Create from dict

Client ID Generation

If client_id is not specified, it's auto-generated using MAC address + UUID:

• Format: {mac_address}_{uuid_suffix}
• Example: a1b2c3d4e5f6_abc12345

Command Line

# Run server
python -m pywayne.cross_comm server

# Run client
python -m pywayne.cross_comm client

Important Notes

• File transfer: Requires OSS environment variables; files auto-upload on send
• Async required: All operations are async; use asyncio.run() or await in async context
• Heartbeat: Auto-managed; adjust intervals for network conditions
• Message filtering: Use download_directory to control auto-downloads and save bandwidth
• State persistence: Server saves client status to cross_comm_clients.yaml
• Role-specific methods: Server has start_server(), get_online_clients(); client has login(), logout(), send_message(), list_clients()