Merge pull request #27 from zixuanzh/peer-info

Peer info

peer/README.md

@@ -1,3 +1,5 @@
 # PeerStore
 
 The PeerStore contains a mapping of peer IDs to PeerData objects. Each PeerData object represents a peer, and each PeerData contains a collection of protocols, addresses, and a mapping of metadata. PeerStore implements the IPeerStore (peer protocols), IAddrBook (address book), and IPeerMetadata (peer metadata) interfaces, which allows the peer store to effectively function as a dictionary for peer ID to protocol, address, and metadata. 
+
+Note: PeerInfo represents a read-only summary of a PeerData object. Only the attributes assigned in PeerInfo are readable by references to PeerInfo objects.

peer/peerdata.py

@@ -27,5 +27,10 @@ class PeerData(IPeerData):
 
     def get_metadata(self, key):
         if key in self.metadata:
-            return self.metadata[key], None
-        return None, "key not found"
+            return self.metadata[key]
+        else:
+            raise PeerDataError("key not found")
+
+class PeerDataError(KeyError):
+    """Raised when a key is not found in peer metadata"""
+    pass

peer/peerdata_interface.py

@@ -35,13 +35,15 @@ class IPeerData(ABC):
     """
     :param key: key in KV pair
     :param val: val to associate with key
+    :raise Exception: unsuccesful put
     """
     def put_metadata(self, key, val):
         pass
 
     """
     :param key: key in KV pair
-    :return: val for key, error (only defined if key not found)
+    :return: val for key
+    :raise Exception: key not found
     """
     def get_metadata(self, key):
         pass

peer/peerinfo.py

@@ -0,0 +1,4 @@
+class PeerInfo:
+    def __init__(self, peer_id, peer_data):
+        self.peer_id = peer_id
+        self.addrs = peer_data.get_addrs()

peer/peermetadata_interface.py

@@ -10,7 +10,8 @@ class IPeerMetadata(ABC):
         """
         :param peer_id: peer ID to lookup key for
         :param key: key to look up
-        :return: value at key for given peer, error
+        :return: value at key for given peer
+        :raise Exception: peer ID not found
         """
         pass
 
@@ -20,7 +21,7 @@ class IPeerMetadata(ABC):
         :param peer_id: peer ID to lookup key for
         :param key: key to associate with peer
         :param val: value to associated with key
-        :return: error
+        :raise Exception: unsuccessful put
         """
         pass
         

peer/peerstore.py

@@ -1,5 +1,6 @@
 from .peerstore_interface import IPeerStore
 from .peerdata import PeerData
+from .peerinfo import PeerInfo
 
 class PeerStore(IPeerStore):
 
@@ -24,16 +25,14 @@ class PeerStore(IPeerStore):
     def peer_info(self, peer_id):
         if peer_id in self.peer_map:
             peer = self.peer_map[peer_id]
-            return {
-                "peer_id": peer_id,
-                "addrs": peer.get_addrs()
-            }
+            return PeerInfo(peer_id, peer)
         return None
 
     def get_protocols(self, peer_id):
         if peer_id in self.peer_map:
-            return self.peer_map[peer_id].get_protocols(), None
-        return None, peer_id + " not found"
+            return self.peer_map[peer_id].get_protocols()
+        else:
+            raise PeerStoreError("peer ID not found")
 
     def add_protocols(self, peer_id, protocols):
         peer = self.__create_or_get_peer(peer_id)
@@ -44,9 +43,10 @@ class PeerStore(IPeerStore):
 
     def get(self, peer_id, key):
         if peer_id in self.peer_map:
-            val, error = self.peer_map[peer_id].get_metadata(key)
-            return val, error
-        return None, peer_id + " not found"
+            val = self.peer_map[peer_id].get_metadata(key)
+            return val
+        else:
+            raise PeerStoreError("peer ID not found")
 
     def put(self, peer_id, key, val):
         # <<?>>
@@ -64,8 +64,9 @@ class PeerStore(IPeerStore):
 
     def addrs(self, peer_id):
         if peer_id in self.peer_map:
-            return self.peer_map[peer_id].get_addrs(), None
-        return None, peer_id + " not found"
+            return self.peer_map[peer_id].get_addrs()
+        else:
+            raise PeerStoreError("peer ID not found")
 
     def clear_addrs(self, peer_id):
         # Only clear addresses if the peer is in peer map
@@ -80,3 +81,7 @@ class PeerStore(IPeerStore):
             if len(self.peer_map[key].get_addrs()) >= 1:
                 output.append(key)
         return output
+
+class PeerStoreError(KeyError):
+    """Raised when peer ID is not found in peer store"""
+    pass

peer/peerstore_interface.py

@@ -20,7 +20,8 @@ class IPeerStore(ABC, IAddrBook, IPeerMetadata):
     def get_protocols(self, peer_id):
         """
         :param peer_id: peer ID to get protocols for
-        :return: protocols (as strings), error
+        :return: protocols (as strings)
+        :raise Exception: peer ID not found exception
         """
         pass
 
@@ -29,7 +30,7 @@ class IPeerStore(ABC, IAddrBook, IPeerMetadata):
         """
         :param peer_id: peer ID to add protocols for
         :param protocols: protocols to add
-        :return: error
+        :raise Exception: peer ID not found
         """
         pass
 
@@ -38,7 +39,7 @@ class IPeerStore(ABC, IAddrBook, IPeerMetadata):
         """
         :param peer_id: peer ID to set protocols for
         :param protocols: protocols to set
-        :return: error
+        :raise Exception: peer ID not found
         """
         pass