def download(self, filename, path):
# step1: Client contacts tracker with the filename it wants to obtain, tracker returns hashed_value_of_file,
# as well as a node in Chord (as the entrance of Chord)
with grpc.insecure_channel(self.tracker_addr) as channel:
stub = p2p_service_pb2_grpc.P2PStub(channel)
request = p2p_service_pb2.LookUpFileRequest(filename=filename)
try:
response = stub.rpc_look_up_file(request, timeout=20)
except Exception:
print("RPC failed from download() position 1")
return
if response.result == -1:
print('Failed while looking up file on tracker')
return
elif response.result == -2:
print('File not found')
return
hashed_value_of_file = response.hashed_value_of_file
self.entrance_addr = response.entrance_addr
# step2: Client contacts the entrance, get a list of fileholder_addr
result, addr_list = self.get(hashed_value_of_file=hashed_value_of_file)
# response: {int32 result: -1 for failed, 0 for succeeded; repeated Address addr_list}
if result == -1:
print('Failed while getting fileholder\'s addresses from Chord')
return
print(addr_list)
# Client picks one addr randomly and contacts it to download.
# This client can also register in Chord as a fileholder
download_addr = random.choice(addr_list)
print('Chosen address of peer node: {}'.format(download_addr))
with grpc.insecure_channel(download_addr) as channel:
stub = p2p_service_pb2_grpc.P2PStub(channel)
request = p2p_service_pb2.DownloadRequest(
hashed_value_of_file=hashed_value_of_file)
try:
response = stub.rpc_download(request, timeout=20)
# response: {int32 result: -1 for file not found, 0 for succeeded; string file}
except Exception as e:
print("RPC failed from download() position 2")
print(e)
return
if response.result == -1:
print('File not found')
return
file = response.file
# write the file into local file
try:
with open(path + filename, 'wb') as f:
f.write(file)
except Exception as e:
print('Failed while storing the downloaded file to local')
return
print('Download succeeded!')
def remove_chord_node_from_tracker(self, remove_addr):
with grpc.insecure_channel(self.tracker_addr) as channel:
stub = p2p_service_pb2_grpc.P2PStub(channel)
request = p2p_service_pb2.RemoveChordNodeRequest(addr=remove_addr) # current successor is the leaved node
try:
response = stub.rpc_remove_chord_node(request)
if response.result == -1:
print('[notify tracker remove node failed] nodeId{} remove_chord_node_from_tracker removed nodeId{} failed'.format(self.id, self.successor[0]))
except Exception:
self.logger.error("Node#{} rpc error when remove node{} from tracker".format(self.id, self.successor[0]))
def add_chord_node_to_tracker(self, add_addr):
with grpc.insecure_channel(self.tracker_addr) as channel:
stub = p2p_service_pb2_grpc.P2PStub(channel)
request = p2p_service_pb2.AddChordNodeRequest(addr=add_addr)
try:
response = stub.rpc_add_chord_node(request)
if response.result == -1:
print('[notify tracker add node failed] nodeId{} add_chord_node_to_tracker new nodeId{} failed'.format(self.id, self.successor[0]))
except Exception:
self.logger.error("Node#{} rpc error when add node{} to tracker".format(self.id, self.successor[0]))
def show_debug_info(self):
with grpc.insecure_channel(self.tracker_addr) as channel:
stub = p2p_service_pb2_grpc.P2PStub(channel)
request = p2p_service_pb2.GetDebugRequest()
try:
response = stub.rpc_get_debug(request, timeout=20)
except Exception:
print("RPC failed from show_debug_info()")
return
print(response.debug_info)
def check_and_fill_entrance(self):
if self.entrance_addr:
return
with grpc.insecure_channel(self.tracker_addr) as channel:
stub = p2p_service_pb2_grpc.P2PStub(channel)
request = p2p_service_pb2.GetEntranceRequest()
try:
response = stub.rpc_get_entrance(request, timeout=20)
except Exception:
print("RPC failed from check_and_fill_entrance()")
return -1, list()
self.entrance_addr = response.entrance_addr
def upload(self, filename):
try:
with open(filename, 'rb') as f:
lines = f.readlines()
except Exception as e:
print('Cannot open file')
return
file = b''
for line in lines:
file += line
hashed_value_of_file = utils.sha1(file)
# step 1: Register (filename, hashed_value_of_file) at tracker
with grpc.insecure_channel(self.tracker_addr) as channel:
stub = p2p_service_pb2_grpc.P2PStub(channel)
request = p2p_service_pb2.RegisterFileRequest(
filename=filename, hashed_value_of_file=hashed_value_of_file)
try:
response = stub.rpc_register_file(request, timeout=20)
except Exception:
print("RPC failed")
return
if response.result == -1:
print('Failed while registering to tracker')
return
# step2: Tracker gives fileholder the addr of a node in Chord (as the entrance of Chord)
# this is piggybacked in the return of RPC register_file
self.entrance_addr = response.entrance_addr
# step3: Fileholder put(hashed_value_of_file, fileholder_addr) to Chord
result = self.put(hashed_value_of_file=hashed_value_of_file,
fileholder_addr=self.addr)
# response: {int32 result: -1 for failed, 0 for succeeded;}
if result == -1:
print('Failed while putting local address to Chord')
return
# store this file into local memory storage
global local_files
local_files[hashed_value_of_file] = file
if not self.file_server:
# start file server
server = threading.Thread(target=start_file_server,
args=(self.addr, ))
server.start()
print('Upload succeeded!')