added event emmiter

examples/discovery/mDNS/mDNS.py

@@ -1,9 +1,21 @@
 import secrets
+
 import multiaddr
 import trio
 
-from libp2p import new_host
-from libp2p.crypto.secp256k1 import create_new_key_pair
+from libp2p import (
+    new_host,
+)
+from libp2p.abc import (
+    PeerInfo,
+)
+from libp2p.crypto.secp256k1 import (
+    create_new_key_pair,
+)
+from libp2p.discovery.events.peerDiscovery import (
+    peerDiscovery,
+)
+
 
 async def main():
     # Generate a key pair for the host
@@ -17,20 +29,19 @@ async def main():
     host = new_host(key_pair=key_pair, enable_mDNS=True)
 
     async with host.run(listen_addrs=[listen_addr]):
-        print("Host started!")
-        print("Peer ID:", host.get_id())
-        print("Listening on:", [str(addr) for addr in host.get_addrs()])
+        print("host peer id", host.get_id())
 
         # Print discovered peers via mDNS
         print("Waiting for mDNS peer discovery events (Ctrl+C to exit)...")
         try:
             while True:
-                # Print all known peers every 5 seconds
-                peers = host.get_peerstore().peer_ids()
-                print("Known peers:", [str(p) for p in peers if p != host.get_id()])
-                await trio.sleep(5)
+                peer_info = PeerInfo(host.get_id(), host.get_addrs())
+
+                await trio.sleep(1)
+                await peerDiscovery.emit_peer_discovered(peer_info=peer_info)
         except KeyboardInterrupt:
             print("Exiting...")
 
+
 if __name__ == "__main__":
-    trio.run(main)
+    trio.run(main)

libp2p/__init__.py

@@ -32,6 +32,9 @@ from libp2p.custom_types import (
     TProtocol,
     TSecurityOptions,
 )
+from libp2p.discovery.mdns.mdns import (
+    MDNSDiscovery,
+)
 from libp2p.host.basic_host import (
     BasicHost,
 )
@@ -71,9 +74,6 @@ from libp2p.transport.upgrader import (
 from libp2p.utils.logging import (
     setup_logging,
 )
-from libp2p.discovery.mdns.mdns import (
-    MDNSDiscovery
-)
 
 # Initialize logging configuration
 setup_logging()
@@ -269,16 +269,13 @@ def new_host(
         listen_addrs=listen_addrs,
     )
 
-    if disc_opt is not None:
-        host = RoutedHost(swarm, disc_opt)
-    else:
-        host = BasicHost(swarm)
-
     if enable_mDNS:
         mdns = MDNSDiscovery(swarm)
         mdns.start()
-        host._mdns = mdns 
-        
-    return host
+
+    if disc_opt is not None:
+        return RoutedHost(swarm, disc_opt)
+    else:
+        return BasicHost(swarm)
 
 __version__ = __version("libp2p")

libp2p/discovery/events/peerDiscovery.py

@@ -0,0 +1,37 @@
+from collections.abc import (
+    Awaitable,
+    Callable,
+)
+
+import trio
+
+from libp2p.abc import (
+    PeerInfo,
+)
+
+TTL: int = 60 * 60  # Time-to-live for discovered peers in seconds
+
+
+class PeerDiscovery:
+    def __init__(self) -> None:
+        self._peer_discovered_handlers: list[Callable[[PeerInfo], Awaitable[None]]] = []
+
+    def register_peer_discovered_handler(
+        self, handler: Callable[[PeerInfo], Awaitable[None]]
+    ) -> None:
+        self._peer_discovered_handlers.append(handler)
+
+    async def emit_peer_discovered(self, peer_info: PeerInfo) -> None:
+        for handler in self._peer_discovered_handlers:
+            await handler(peer_info)
+
+
+peerDiscovery = PeerDiscovery()
+
+
+async def peerDiscoveryHandler(peerInfo: PeerInfo) -> None:
+    await trio.sleep(5)  # Simulate some processing delay
+    # print("Discovered peer is", peerInfo.peer_id)
+
+
+peerDiscovery.register_peer_discovered_handler(peerDiscoveryHandler)

libp2p/discovery/mdns/broadcaster.py

@@ -1,32 +1,45 @@
-from zeroconf import Zeroconf, ServiceInfo
-from .utils import stringGen
 import socket
 
+from zeroconf import (
+    ServiceInfo,
+    Zeroconf,
+)
+
+
 class PeerBroadcaster:
     """
     Broadcasts this peer's presence on the local network using mDNS/zeroconf.
     Registers a service with the peer's ID in the TXT record as per libp2p spec.
     """
-    def __init__(self, zeroconf: Zeroconf, service_type: str, service_name: str, peer_id: str, port: int):
+
+    def __init__(
+        self,
+        zeroconf: Zeroconf,
+        service_type: str,
+        service_name: str,
+        peer_id: str,
+        port: int,
+    ):
         self.zeroconf = zeroconf
         self.service_type = service_type
         self.peer_id = peer_id
         self.port = port
         self.service_name = service_name
-        
+
         # Get the local IP address
         local_ip = self._get_local_ip()
-        
+        hostname = socket.gethostname()
+
         self.service_info = ServiceInfo(
             type_=self.service_type,
             name=self.service_name,
             port=self.port,
-            properties={b'id': self.peer_id.encode()},
-            server=f"{self.service_name}",
-            addresses=[socket.inet_aton(local_ip)]
+            properties={b"id": self.peer_id.encode()},
+            server=f"{hostname}.local.",
+            addresses=[socket.inet_aton(local_ip)],
         )
 
-    def _get_local_ip(self):
+    def _get_local_ip(self) -> str:
         """Get the local IP address of this machine"""
         try:
             # Connect to a remote address to determine the local IP
@@ -34,16 +47,17 @@ class PeerBroadcaster:
             with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as s:
                 s.connect(("8.8.8.8", 80))
                 local_ip = s.getsockname()[0]
+                print(f"Local IP determined: {local_ip}")
             return local_ip
         except Exception:
             # Fallback to localhost if we can't determine the IP
             return "127.0.0.1"
 
-    def register(self):
+    def register(self) -> None:
         """Register the peer's mDNS service on the network."""
-        print(f"Registering with name {self.service_name} and peer_id {self.peer_id} on port {self.port}")
+        print(repr(self.service_info))
         self.zeroconf.register_service(self.service_info)
 
-    def unregister(self):
+    def unregister(self) -> None:
         """Unregister the peer's mDNS service from the network."""
         self.zeroconf.unregister_service(self.service_info)

libp2p/discovery/mdns/listener.py

@@ -1,102 +1,105 @@
-import time
 import socket
-from zeroconf import ServiceBrowser, ServiceStateChange, Zeroconf
-from libp2p.peer.peerinfo import PeerInfo
-from libp2p.peer.id import ID
+import time
 
-class PeerListener:
-    """Enhanced mDNS listener for libp2p peer discovery."""
-    
-    def __init__(self, zeroconf: Zeroconf, service_type: str, service_name: str, on_peer_discovery=None):
+from zeroconf import (
+    ServiceBrowser,
+    ServiceInfo,
+    ServiceListener,
+    ServiceStateChange,
+    Zeroconf,
+)
+
+from libp2p.abc import IPeerStore
+from libp2p.peer.id import ID
+from libp2p.peer.peerinfo import PeerInfo
+
+
+class PeerListener(ServiceListener):
+    """mDNS listener — now a true ServiceListener subclass."""
+
+    def __init__(
+        self,
+        peerstore: IPeerStore,
+        zeroconf: Zeroconf,
+        service_type: str,
+        service_name: str,
+    ) -> None:
+        self.peerstore = peerstore
         self.zeroconf = zeroconf
         self.service_type = service_type
         self.service_name = service_name
-        self.on_peer_discovery = on_peer_discovery
-        self.discovered_services = set()
-        self.browser = ServiceBrowser(
-            self.zeroconf, self.service_type, handlers=[self.on_service_state_change]
-        )
+        self.discovered_services: set[str] = set()
 
-    def on_service_state_change(self, zeroconf: Zeroconf, service_type, name, state_change):
-        if state_change != ServiceStateChange.Added or name == self.service_name or name in self.discovered_services:
+        # pass `self` as the listener object
+        self.browser = ServiceBrowser(self.zeroconf, self.service_type, listener=self)
+
+    def add_service(self, zc: Zeroconf, type_: str, name: str) -> None:
+        # map to your on_service_state_change logic
+        self._on_state_change(zc, type_, name, ServiceStateChange.Added)
+
+    def remove_service(self, zc: Zeroconf, type_: str, name: str) -> None:
+        self._on_state_change(zc, type_, name, ServiceStateChange.Removed)
+
+    def update_service(self, zc: Zeroconf, type_: str, name: str) -> None:
+        self._on_state_change(zc, type_, name, ServiceStateChange.Updated)
+
+    def _on_state_change(
+        self,
+        zeroconf: Zeroconf,
+        service_type: str,
+        name: str,
+        state: ServiceStateChange,
+    ) -> None:
+        # skip our own service
+        if name == self.service_name:
             return
-            
-        print(f"Discovered service: {name}")
-        self.discovered_services.add(name)
-        
-        # Process the discovered service
-        self._process_discovered_service(zeroconf, service_type, name)
 
-    def _process_discovered_service(self, zeroconf, service_type, name):
-        # Try to get service info with retries
+        # handle Added
+        if state is ServiceStateChange.Added:
+            if name in self.discovered_services:
+                return
+            self.discovered_services.add(name)
+            self._process_discovered_service(zeroconf, service_type, name)
+
+        # ...optional hooks for Removed/Updated if you need them
+
+    def _process_discovered_service(
+        self, zeroconf: Zeroconf, service_type: str, name: str
+    ) -> None:
+        # same retry logic you had before
         info = None
         for attempt in range(3):
             info = zeroconf.get_service_info(service_type, name, timeout=5000)
             if info:
-                print(f"Service info successfully retrieved for {name}")
                 break
-            print(f"Retrying service info retrieval (attempt {attempt + 1}/3)")
             time.sleep(1)
 
         if not info:
-            print(f"Failed to retrieve service info for {name}")
             return
 
-        # Extract peer information
         peer_info = self._extract_peer_info(info)
-        print(f"Extracted peer info: {peer_info}")
         if peer_info:
+            # your existing hook
             self._handle_discovered_peer(peer_info)
 
-    def _extract_peer_info(self, service_info):
+    def _extract_peer_info(self, info: ServiceInfo) -> PeerInfo | None:
         try:
-            # Extract IP addresses
-            addresses = []
-            for addr in service_info.addresses:
-                ip = socket.inet_ntoa(addr)
-                addresses.append(ip)
-            
-            # Extract port
-            port = service_info.port
-            
-            # Extract peer ID from TXT record
-            peer_id = None
-            if service_info.properties:
-                peer_id_bytes = service_info.properties.get(b'id')
-                if peer_id_bytes:
-                    peer_id = peer_id_bytes.decode('utf-8')
-            
-            if not peer_id:
-                print(f"No peer ID found in TXT record for {service_info.name}")
+            addrs = [
+                f"/ip4/{socket.inet_ntoa(addr)}/udp/{info.port}"
+                for addr in info.addresses
+            ]
+            pid_bytes = info.properties.get(b"id")
+            if not pid_bytes:
                 return None
-            
-            # Create multiaddresses
-            multiaddrs = []
-            for ip in addresses:
-                multiaddr = f"/ip4/{ip}/udp/{port}"
-                multiaddrs.append(multiaddr)
-            
-            # Create PeerInfo object
-            peer_info = PeerInfo(
-                peer_id=ID.from_base58(peer_id),
-                addrs=multiaddrs
-            )
-            
-            return peer_info
-            
-        except Exception as e:
-            print(f"Error extracting peer info from {service_info.name}: {e}")
+            pid = ID.from_base58(pid_bytes.decode())
+            return PeerInfo(peer_id=pid, addrs=addrs)
+        except Exception:
             return None
 
-    def _handle_discovered_peer(self, peer_info):
-        print(f"Successfully discovered peer: {peer_info.peer_id}")
-        print(f"Peer addresses: {peer_info.addrs}")
-        
-        # Trigger callback if provided
-        if self.on_peer_discovery:
-            self.on_peer_discovery(peer_info)
+    def _handle_discovered_peer(self, peer_info: PeerInfo) -> None:
+        # your “emit” or “connect” logic goes here
+        # print("Discovered:", peer_info)
+        print("Discovered:", peer_info.peer_id)
 
-    def stop(self):
-        """Stop the listener."""
-        if self.browser:
-            self.browser.cancel()
+    def stop(self) -> None:
+        self.browser.cancel()

libp2p/discovery/mdns/mdns.py

@@ -3,55 +3,65 @@ mDNS-based peer discovery for py-libp2p.
 Conforms to https://github.com/libp2p/specs/blob/master/discovery/mdns.md
 Uses zeroconf for mDNS broadcast/listen. Async operations use trio.
 """
-import trio
-from typing import Callable, Optional
-from zeroconf import ServiceInfo, Zeroconf, ServiceBrowser, ServiceStateChange
-from .utils import (
-    stringGen
+
+from zeroconf import (
+    Zeroconf,
 )
+
 from libp2p.abc import (
-    INetworkService
+    INetworkService,
+)
+
+from .broadcaster import (
+    PeerBroadcaster,
+)
+from .listener import (
+    PeerListener,
+)
+from .utils import (
+    stringGen,
 )
-from .listener import PeerListener
-from .broadcaster import PeerBroadcaster
-from libp2p.peer.peerinfo import PeerInfo
 
 SERVICE_TYPE = "_p2p._udp.local."
 MCAST_PORT = 5353
 MCAST_ADDR = "224.0.0.251"
 
+
 class MDNSDiscovery:
     """
     mDNS-based peer discovery for py-libp2p, using zeroconf.
     Conforms to the libp2p mDNS discovery spec.
     """
-    def __init__(self, swarm: INetworkService, port: int = 8000, on_peer_discovery=None):
+
+    def __init__(self, swarm: INetworkService, port: int = 8000):
         self.peer_id = str(swarm.get_peer_id())
         self.port = port
-        self.on_peer_discovery = on_peer_discovery
         self.zeroconf = Zeroconf()
         self.serviceName = f"{stringGen()}.{SERVICE_TYPE}"
+        self.peerstore = swarm.peerstore
+        self.swarm = swarm
         self.broadcaster = PeerBroadcaster(
             zeroconf=self.zeroconf,
             service_type=SERVICE_TYPE,
             service_name=self.serviceName,
-            peer_id = self.peer_id,
-            port = self.port
+            peer_id=self.peer_id,
+            port=self.port,
         )
         self.listener = PeerListener(
             zeroconf=self.zeroconf,
+            peerstore=self.peerstore,
             service_type=SERVICE_TYPE,
             service_name=self.serviceName,
-            on_peer_discovery=self.on_peer_discovery
         )
 
-    def start(self):
+    def start(self) -> None:
         """Register this peer and start listening for others."""
         print(f"Starting mDNS discovery for peer {self.peer_id} on port {self.port}")
+        print("host is listening on", self.swarm.listeners)
         self.broadcaster.register()
         # Listener is started in constructor
 
-    def stop(self):
+    def stop(self) -> None:
         """Unregister this peer and clean up zeroconf resources."""
         self.broadcaster.unregister()
-        self.zeroconf.close()
+        self.zeroconf.close()

libp2p/discovery/mdns/utils.py

@@ -1,11 +1,11 @@
 import random
 import string
 
+
 def stringGen(len: int = 63) -> str:
     """Generate a random string of lowercase letters and digits."""
-
     charset = string.ascii_lowercase + string.digits
     result = []
     for _ in range(len):
         result.append(random.choice(charset))
-    return ''.join(result)
+    return "".join(result)