implement persistent peerstore with Protocol Buffer serialization, context managers, and configurable sync

Author: Winter-Soren

examples/persistent_peerstore/example_usage.py

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+#!/usr/bin/env python3
+"""
+Example usage of persistent peerstore with safe serialization.
+
+This example demonstrates how to use the new persistent peerstore implementation
+with Protocol Buffer serialization instead of unsafe pickle.
+"""
+
+import asyncio
+from pathlib import Path
+import tempfile
+
+from multiaddr import Multiaddr
+
+from libp2p.peer.id import ID
+from libp2p.peer.persistent import (
+    create_async_peerstore,
+    create_sync_peerstore,
+)
+
+
+async def async_example():
+    """Demonstrate async persistent peerstore usage."""
+    print("=== Async Persistent Peerstore Example ===")
+    
+    with tempfile.TemporaryDirectory() as temp_dir:
+        db_path = Path(temp_dir) / "async_peers.db"
+        
+        # Create peerstore with safe serialization and configurable sync
+        async with create_async_peerstore(
+            db_path=db_path,
+            backend="sqlite",
+            sync_interval=0.5,  # Sync every 0.5 seconds
+            auto_sync=True
+        ) as peerstore:
+            
+            # Create a test peer
+            peer_id = ID.from_base58("QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN")
+            
+            # Add some addresses
+            addr1 = Multiaddr("/ip4/127.0.0.1/tcp/4001")
+            addr2 = Multiaddr("/ip6/::1/tcp/4001")
+            
+            await peerstore.add_addrs_async(peer_id, [addr1, addr2], 3600)
+            
+            # Add protocols
+            await peerstore.add_protocols_async(peer_id, ["/ipfs/ping/1.0.0", "/ipfs/id/1.0.0"])
+            
+            # Add metadata
+            await peerstore.put_async(peer_id, "agent", "py-libp2p-example")
+            
+            print(f"Added peer {peer_id}")
+            print(f"Addresses: {await peerstore.addrs_async(peer_id)}")
+            print(f"Protocols: {await peerstore.get_protocols_async(peer_id)}")
+            print(f"Metadata: {await peerstore.get_async(peer_id, 'agent')}")
+            
+        print("Peerstore closed safely using context manager")
+
+
+def sync_example():
+    """Demonstrate sync persistent peerstore usage."""
+    print("\n=== Sync Persistent Peerstore Example ===")
+    
+    with tempfile.TemporaryDirectory() as temp_dir:
+        db_path = Path(temp_dir) / "sync_peers.db"
+        
+        # Create peerstore with safe serialization and configurable sync
+        with create_sync_peerstore(
+            db_path=db_path,
+            backend="sqlite",
+            sync_interval=1.0,  # Sync every 1 second
+            auto_sync=False  # Manual sync control
+        ) as peerstore:
+            
+            # Create a test peer
+            peer_id = ID.from_base58("QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN")
+            
+            # Add some addresses
+            addr1 = Multiaddr("/ip4/192.168.1.100/tcp/4001")
+            addr2 = Multiaddr("/ip4/10.0.0.1/tcp/4001")
+            
+            peerstore.add_addrs(peer_id, [addr1, addr2], 7200)
+            
+            # Add protocols
+            peerstore.add_protocols(peer_id, ["/libp2p/circuit/relay/0.1.0"])
+            
+            # Add metadata
+            peerstore.put(peer_id, "version", "1.0.0")
+            
+            # Manual sync since auto_sync=False
+            peerstore.datastore.sync(b"")
+            
+            print(f"Added peer {peer_id}")
+            print(f"Addresses: {peerstore.addrs(peer_id)}")
+            print(f"Protocols: {peerstore.get_protocols(peer_id)}")
+            print(f"Metadata: {peerstore.get(peer_id, 'version')}")
+            
+        print("Peerstore closed safely using context manager")
+
+
+def security_example():
+    """Demonstrate security improvements."""
+    print("\n=== Security Improvements ===")
+    print("✅ Replaced unsafe pickle with Protocol Buffers")
+    print("✅ Added context manager support for proper resource cleanup")
+    print("✅ Improved SQLite thread safety with WAL mode")
+    print("✅ Added configurable sync for better performance")
+    print("✅ Enhanced error handling with specific exceptions")
+    print("✅ Added proper file permissions (0600) for database files")
+
+
+if __name__ == "__main__":
+    # Run async example
+    asyncio.run(async_example())
+    
+    # Run sync example
+    sync_example()
+    
+    # Show security improvements
+    security_example()
+    
+    print("\n🎉 All examples completed successfully!")
+    print("The persistent peerstore now uses safe Protocol Buffer serialization")
+    print("and provides better resource management and performance control.")