def test_ids_basic():
# basic functionality tests
for i in range(100):
id1, id2 = DHTID.generate(), DHTID.generate()
assert DHTID.MIN <= id1 < DHTID.MAX and DHTID.MIN <= id2 <= DHTID.MAX
assert DHTID.xor_distance(id1, id1) == DHTID.xor_distance(id2,
id2) == 0
assert DHTID.xor_distance(id1, id2) > 0 or (id1 == id2)
assert DHTID.from_bytes(bytes(id1)) == id1 and DHTID.from_bytes(
id2.to_bytes()) == id2
async def rpc_ping(self, request: dht_pb2.PingRequest,
context: grpc.ServicerContext):
""" Some node wants us to add it to our routing table. """
response = dht_pb2.PingResponse(peer=self.node_info,
sender_endpoint=context.peer(),
dht_time=get_dht_time(),
available=False)
if request.peer and request.peer.node_id and request.peer.rpc_port:
sender_id = DHTID.from_bytes(request.peer.node_id)
if request.peer.endpoint != dht_pb2.NodeInfo.endpoint.DESCRIPTOR.default_value:
sender_endpoint = request.peer.endpoint # if peer has preferred endpoint, use it
else:
sender_endpoint = replace_port(context.peer(),
new_port=request.peer.rpc_port)
response.sender_endpoint = sender_endpoint
if request.validate:
response.available = await self.call_ping(
response.sender_endpoint, validate=False) == sender_id
asyncio.create_task(
self.update_routing_table(sender_id,
sender_endpoint,
responded=response.available
or not request.validate))
return response
async def rpc_find(self, request: dht_pb2.FindRequest, context: grpc.ServicerContext) -> dht_pb2.FindResponse:
"""
Someone wants to find keys in the DHT. For all keys that we have locally, return value and expiration
Also return :bucket_size: nearest neighbors from our routing table for each key (whether or not we found value)
"""
if request.peer: # if requested, add peer to the routing table
asyncio.create_task(self.rpc_ping(dht_pb2.PingRequest(peer=request.peer), context))
response = dht_pb2.FindResponse(results=[], peer=self.node_info)
for i, key_id in enumerate(map(DHTID.from_bytes, request.keys)):
maybe_item = self.storage.get(key_id)
cached_item = self.cache.get(key_id)
if cached_item is not None and (maybe_item is None
or cached_item.expiration_time > maybe_item.expiration_time):
maybe_item = cached_item
if maybe_item is None: # value not found
item = dht_pb2.FindResult(type=dht_pb2.NOT_FOUND)
elif isinstance(maybe_item.value, DictionaryDHTValue):
item = dht_pb2.FindResult(type=dht_pb2.FOUND_DICTIONARY, value=self.serializer.dumps(maybe_item.value),
expiration_time=maybe_item.expiration_time)
else: # found regular value
item = dht_pb2.FindResult(type=dht_pb2.FOUND_REGULAR, value=maybe_item.value,
expiration_time=maybe_item.expiration_time)
for node_id, endpoint in self.routing_table.get_nearest_neighbors(
key_id, k=self.bucket_size, exclude=DHTID.from_bytes(request.peer.node_id)):
item.nearest_node_ids.append(node_id.to_bytes())
item.nearest_endpoints.append(endpoint)
response.results.append(item)
return response
async def rpc_store(self, request: dht_pb2.StoreRequest, context: grpc.ServicerContext) -> dht_pb2.StoreResponse:
""" Some node wants us to store this (key, value) pair """
if request.peer: # if requested, add peer to the routing table
asyncio.create_task(self.rpc_ping(dht_pb2.PingRequest(peer=request.peer), context))
assert len(request.keys) == len(request.values) == len(request.expiration_time) == len(request.in_cache)
response = dht_pb2.StoreResponse(store_ok=[], peer=self.node_info)
for key, tag, value_bytes, expiration_time, in_cache in zip(
request.keys, request.subkeys, request.values, request.expiration_time, request.in_cache):
key_id = DHTID.from_bytes(key)
storage = self.cache if in_cache else self.storage
if tag == self.IS_DICTIONARY: # store an entire dictionary with several subkeys
value_dictionary = self.serializer.loads(value_bytes)
assert isinstance(value_dictionary, DictionaryDHTValue)
if not self._validate_dictionary(key, value_dictionary):
response.store_ok.append(False)
continue
response.store_ok.append(all(storage.store_subkey(key_id, subkey, item.value, item.expiration_time)
for subkey, item in value_dictionary.items()))
continue
if not self._validate_record(key, tag, value_bytes, expiration_time):
response.store_ok.append(False)
continue
if tag == self.IS_REGULAR_VALUE: # store normal value without subkeys
response.store_ok.append(storage.store(key_id, value_bytes, expiration_time))
else: # add a new entry into an existing dictionary value or create a new dictionary with one sub-key
subkey = self.serializer.loads(tag)
response.store_ok.append(storage.store_subkey(key_id, subkey, value_bytes, expiration_time))
return response
async def call_find(
self, peer: Endpoint, keys: Collection[DHTID]
) -> Optional[Dict[DHTID, Tuple[Optional[ValueWithExpiration[Union[
BinaryDHTValue, DictionaryDHTValue]]], Dict[DHTID, Endpoint]]]]:
"""
Request keys from a peer. For each key, look for its (value, expiration time) locally and
k additional peers that are most likely to have this key (ranked by XOR distance)
:returns: A dict key => Tuple[optional value, optional expiration time, nearest neighbors]
value: value stored by the recipient with that key, or None if peer doesn't have this value
expiration time: expiration time of the returned value, None if no value was found
neighbors: a dictionary[node_id : endpoint] containing nearest neighbors from peer's routing table
If peer didn't respond, returns None
"""
keys = list(keys)
find_request = dht_pb2.FindRequest(keys=list(map(DHTID.to_bytes,
keys)),
peer=self.node_info)
try:
async with self.rpc_semaphore:
response = await self._get_dht_stub(peer).rpc_find(
find_request, timeout=self.wait_timeout)
if response.peer and response.peer.node_id:
peer_id = DHTID.from_bytes(response.peer.node_id)
asyncio.create_task(
self.update_routing_table(peer_id, peer, responded=True))
assert len(keys) == len(
response.results
), "DHTProtocol: response is not aligned with keys"
output = {} # unpack data depending on its type
for key, result in zip(keys, response.results):
nearest = dict(
zip(map(DHTID.from_bytes, result.nearest_node_ids),
result.nearest_endpoints))
if result.type == dht_pb2.NOT_FOUND:
output[key] = None, nearest
elif result.type == dht_pb2.FOUND_REGULAR:
output[key] = ValueWithExpiration(
result.value, result.expiration_time), nearest
elif result.type == dht_pb2.FOUND_DICTIONARY:
deserialized_dictionary = self.serializer.loads(
result.value)
output[key] = ValueWithExpiration(
deserialized_dictionary,
result.expiration_time), nearest
else:
logger.error(f"Unknown result type: {result.type}")
return output
except grpc.aio.AioRpcError as error:
logger.debug(
f"DHTProtocol failed to find at {peer}: {error.code()}")
asyncio.create_task(
self.update_routing_table(
self.routing_table.get(endpoint=peer),
peer,
responded=False))
async def call_store(
self,
peer: Endpoint,
keys: Sequence[DHTID],
values: Sequence[BinaryDHTValue],
expiration_time: Union[DHTExpiration, Sequence[DHTExpiration]],
in_cache: Optional[Union[bool,
Sequence[bool]]] = None) -> Sequence[bool]:
"""
Ask a recipient to store several (key, value : expiration_time) items or update their older value
:param peer: request this peer to store the data
:param keys: a list of N keys digested by DHTID.generate(source=some_dict_key)
:param values: a list of N serialized values (bytes) for each respective key
:param expiration_time: a list of N expiration timestamps for each respective key-value pair (see get_dht_time())
:param in_cache: a list of booleans, True = store i-th key in cache, value = store i-th key locally
:note: the difference between storing normally and in cache is that normal storage is guaranteed to be stored
until expiration time (best-effort), whereas cached storage can be evicted early due to limited cache size
:return: list of [True / False] True = stored, False = failed (found newer value or no response)
if peer did not respond (e.g. due to timeout or congestion), returns None
"""
if isinstance(expiration_time, DHTExpiration):
expiration_time = [expiration_time] * len(keys)
in_cache = in_cache if in_cache is not None else [False] * len(
keys) # default value (None)
in_cache = [in_cache] * len(keys) if isinstance(
in_cache, bool) else in_cache # single bool
keys, values, expiration_time, in_cache = map(
list, [keys, values, expiration_time, in_cache])
assert len(keys) == len(values) == len(expiration_time) == len(
in_cache), "Data is not aligned"
store_request = dht_pb2.StoreRequest(keys=list(
map(DHTID.to_bytes, keys)),
values=values,
expiration_time=expiration_time,
in_cache=in_cache,
peer=self.node_info)
try:
async with self.rpc_semaphore:
response = await self._get(peer).rpc_store(
store_request, timeout=self.wait_timeout)
if response.peer and response.peer.node_id:
peer_id = DHTID.from_bytes(response.peer.node_id)
asyncio.create_task(
self.update_routing_table(peer_id, peer, responded=True))
return response.store_ok
except grpc.experimental.aio.AioRpcError as error:
logger.warning(
f"DHTProtocol failed to store at {peer}: {error.code()}")
asyncio.create_task(
self.update_routing_table(
self.routing_table.get(endpoint=peer),
peer,
responded=False))
return [False] * len(keys)
async def rpc_ping(self, peer_info: dht_pb2.NodeInfo,
context: grpc.ServicerContext):
""" Some node wants us to add it to our routing table. """
if peer_info.node_id and peer_info.rpc_port:
sender_id = DHTID.from_bytes(peer_info.node_id)
rpc_endpoint = replace_port(context.peer(),
new_port=peer_info.rpc_port)
asyncio.create_task(
self.update_routing_table(sender_id, rpc_endpoint))
return self.node_info
async def call_store(self, peer: Endpoint, keys: Sequence[DHTID],
values: Sequence[Union[BinaryDHTValue, DictionaryDHTValue]],
expiration_time: Union[DHTExpiration, Sequence[DHTExpiration]],
subkeys: Optional[Union[Subkey, Sequence[Optional[Subkey]]]] = None,
in_cache: Optional[Union[bool, Sequence[bool]]] = None) -> Optional[List[bool]]:
"""
Ask a recipient to store several (key, value : expiration_time) items or update their older value
:param peer: request this peer to store the data
:param keys: a list of N keys digested by DHTID.generate(source=some_dict_key)
:param values: a list of N serialized values (bytes) for each respective key
:param expiration_time: a list of N expiration timestamps for each respective key-value pair(see get_dht_time())
:param subkeys: a list of N optional sub-keys. If None, stores value normally. If not subkey is not None:
1) if local storage doesn't have :key:, create a new dictionary {subkey: (value, expiration_time)}
2) if local storage already has a dictionary under :key:, try add (subkey, value, exp_time) to that dictionary
2) if local storage associates :key: with a normal value with smaller expiration, clear :key: and perform (1)
3) finally, if local storage currently associates :key: with a normal value with larger expiration, do nothing
:param in_cache: a list of booleans, True = store i-th key in cache, value = store i-th key locally
:note: the difference between storing normally and in cache is that normal storage is guaranteed to be stored
until expiration time (best-effort), whereas cached storage can be evicted early due to limited cache size
:return: list of [True / False] True = stored, False = failed (found newer value or no response)
if peer did not respond (e.g. due to timeout or congestion), returns None
"""
if isinstance(expiration_time, DHTExpiration):
expiration_time = [expiration_time] * len(keys)
if subkeys is None:
subkeys = [None] * len(keys)
in_cache = in_cache if in_cache is not None else [False] * len(keys) # default value (None)
in_cache = [in_cache] * len(keys) if isinstance(in_cache, bool) else in_cache # single bool
keys, subkeys, values, expiration_time, in_cache = map(list, [keys, subkeys, values, expiration_time, in_cache])
for i in range(len(keys)):
if subkeys[i] is None: # add default sub-key if not specified
subkeys[i] = self.IS_DICTIONARY if isinstance(values[i], DictionaryDHTValue) else self.IS_REGULAR_VALUE
else:
subkeys[i] = self.serializer.dumps(subkeys[i])
if isinstance(values[i], DictionaryDHTValue):
assert subkeys[i] == self.IS_DICTIONARY, "Please don't specify subkey when storing an entire dictionary"
values[i] = self.serializer.dumps(values[i])
assert len(keys) == len(values) == len(expiration_time) == len(in_cache), "Data is not aligned"
store_request = dht_pb2.StoreRequest(keys=list(map(DHTID.to_bytes, keys)), subkeys=subkeys, values=values,
expiration_time=expiration_time, in_cache=in_cache, peer=self.node_info)
try:
async with self.rpc_semaphore:
response = await self._get_dht_stub(peer).rpc_store(store_request, timeout=self.wait_timeout)
if response.peer and response.peer.node_id:
peer_id = DHTID.from_bytes(response.peer.node_id)
asyncio.create_task(self.update_routing_table(peer_id, peer, responded=True))
return response.store_ok
except grpc.aio.AioRpcError as error:
logger.debug(f"DHTProtocol failed to store at {peer}: {error.code()}")
asyncio.create_task(self.update_routing_table(self.routing_table.get(endpoint=peer), peer, responded=False))
return None
async def call_ping(self,
peer: Endpoint,
validate: bool = False,
strict: bool = True) -> Optional[DHTID]:
"""
Get peer's node id and add him to the routing table. If peer doesn't respond, return None
:param peer: string network address, e.g. 123.123.123.123:1337 or [2a21:6с8:b192:2105]:8888
:param validate: if True, validates that node's endpoint is available
:param strict: if strict=True, validation will raise exception on fail, otherwise it will only warn
:note: if DHTProtocol was created with listen=True, also request peer to add you to his routing table
:return: node's DHTID, if peer responded and decided to send his node_id
"""
try:
async with self.rpc_semaphore:
ping_request = dht_pb2.PingRequest(peer=self.node_info,
validate=validate)
time_requested = get_dht_time()
response = await self._get_dht_stub(peer).rpc_ping(
ping_request, timeout=self.wait_timeout)
time_responded = get_dht_time()
except grpc.aio.AioRpcError as error:
logger.debug(f"DHTProtocol failed to ping {peer}: {error.code()}")
response = None
responded = bool(response and response.peer and response.peer.node_id)
if responded and validate:
try:
if self.server is not None and not response.available:
raise ValidationError(
f"Peer {peer} couldn't access this node at {response.sender_endpoint} . "
f"Make sure that this port is open for incoming requests."
)
if response.dht_time != dht_pb2.PingResponse.dht_time.DESCRIPTOR.default_value:
if response.dht_time < time_requested - MAX_DHT_TIME_DISCREPANCY_SECONDS or \
response.dht_time > time_responded + MAX_DHT_TIME_DISCREPANCY_SECONDS:
raise ValidationError(
f"local time must be within {MAX_DHT_TIME_DISCREPANCY_SECONDS} seconds "
f" of others(local: {time_requested:.5f}, peer: {response.dht_time:.5f})"
)
except ValidationError as e:
if strict:
raise
else:
logger.warning(repr(e))
peer_id = DHTID.from_bytes(
response.peer.node_id) if responded else None
asyncio.create_task(
self.update_routing_table(peer_id, peer, responded=responded))
return peer_id
async def call_find(self, peer: Endpoint, keys: Collection[DHTID]) -> \
Optional[Dict[DHTID, Tuple[Optional[BinaryDHTValue], Optional[DHTExpiration], Dict[DHTID, Endpoint]]]]:
"""
Request keys from a peer. For each key, look for its (value, expiration time) locally and
k additional peers that are most likely to have this key (ranked by XOR distance)
:returns: A dict key => Tuple[optional value, optional expiration time, nearest neighbors]
value: value stored by the recipient with that key, or None if peer doesn't have this value
expiration time: expiration time of the returned value, None if no value was found
neighbors: a dictionary[node_id : endpoint] containing nearest neighbors from peer's routing table
If peer didn't respond, returns None
"""
keys = list(keys)
find_request = dht_pb2.FindRequest(keys=list(map(DHTID.to_bytes,
keys)),
peer=self.node_info)
try:
async with self.rpc_semaphore:
response = await self._get(peer).rpc_find(
find_request, timeout=self.wait_timeout)
if response.peer and response.peer.node_id:
peer_id = DHTID.from_bytes(response.peer.node_id)
asyncio.create_task(
self.update_routing_table(peer_id, peer, responded=True))
assert len(response.values) == len(response.expiration_time) == len(response.nearest) == len(keys), \
"DHTProtocol: response is not aligned with keys and/or expiration times"
output = {} # unpack data without special NOT_FOUND_* values
for key, value, expiration_time, nearest in zip(
keys, response.values, response.expiration_time,
response.nearest):
value = value if value != _NOT_FOUND_VALUE else None
expiration_time = expiration_time if expiration_time != _NOT_FOUND_EXPIRATION else None
nearest = dict(
zip(map(DHTID.from_bytes, nearest.node_ids),
nearest.endpoints))
output[key] = (value, expiration_time, nearest)
return output
except grpc.experimental.aio.AioRpcError as error:
logger.warning(
f"DHTProtocol failed to find at {peer}: {error.code()}")
asyncio.create_task(
self.update_routing_table(
self.routing_table.get(endpoint=peer),
peer,
responded=False))
async def rpc_store(
self, request: dht_pb2.StoreRequest,
context: grpc.ServicerContext) -> dht_pb2.StoreResponse:
""" Some node wants us to store this (key, value) pair """
if request.peer: # if requested, add peer to the routing table
asyncio.create_task(self.rpc_ping(request.peer, context))
assert len(request.keys) == len(request.values) == len(
request.expiration_time) == len(request.in_cache)
response = dht_pb2.StoreResponse(store_ok=[], peer=self.node_info)
for key_bytes, value_bytes, expiration_time, in_cache in zip(
request.keys, request.values, request.expiration_time,
request.in_cache):
local_memory = self.cache if in_cache else self.storage
response.store_ok.append(
local_memory.store(DHTID.from_bytes(key_bytes), value_bytes,
expiration_time))
return response
async def call_ping(self, peer: Endpoint) -> Optional[DHTID]:
"""
Get peer's node id and add him to the routing table. If peer doesn't respond, return None
:param peer: string network address, e.g. 123.123.123.123:1337 or [2a21:6с8:b192:2105]:8888
:note: if DHTProtocol was created with listen=True, also request peer to add you to his routing table
:return: node's DHTID, if peer responded and decided to send his node_id
"""
try:
async with self.rpc_semaphore:
peer_info = await self._get(peer).rpc_ping(
self.node_info, timeout=self.wait_timeout)
except grpc.experimental.aio.AioRpcError as error:
logger.warning(
f"DHTProtocol failed to ping {peer}: {error.code()}")
peer_info = None
responded = bool(peer_info and peer_info.node_id)
peer_id = DHTID.from_bytes(peer_info.node_id) if responded else None
asyncio.create_task(
self.update_routing_table(peer_id, peer, responded=responded))
return peer_id
async def rpc_find(self, request: dht_pb2.FindRequest,
context: grpc.ServicerContext) -> dht_pb2.FindResponse:
"""
Someone wants to find keys in the DHT. For all keys that we have locally, return value and expiration
Also return :bucket_size: nearest neighbors from our routing table for each key (whether or not we found value)
"""
if request.peer: # if requested, add peer to the routing table
asyncio.create_task(self.rpc_ping(request.peer, context))
response = dht_pb2.FindResponse(values=[],
expiration_time=[],
nearest=[],
peer=self.node_info)
for key_id in map(DHTID.from_bytes, request.keys):
maybe_value, maybe_expiration_time = self.storage.get(key_id)
cached_value, cached_expiration_time = self.cache.get(key_id)
if (cached_expiration_time or
-float('inf')) > (maybe_expiration_time or -float('inf')):
maybe_value, maybe_expiration_time = cached_value, cached_expiration_time
nearest_neighbors = self.routing_table.get_nearest_neighbors(
key_id,
k=self.bucket_size,
exclude=DHTID.from_bytes(request.peer.node_id))
if nearest_neighbors:
peer_ids, endpoints = zip(*nearest_neighbors)
else:
peer_ids, endpoints = [], []
response.values.append(
maybe_value if maybe_value is not None else _NOT_FOUND_VALUE)
response.expiration_time.append(
maybe_expiration_time
if maybe_expiration_time else _NOT_FOUND_EXPIRATION)
response.nearest.append(
dht_pb2.Peers(node_ids=list(map(DHTID.to_bytes, peer_ids)),
endpoints=endpoints))
return response
