def marco(self, max_nodes=None, exclude=[], params={}, timeout=None, retries=0):
"""
**C struct node * marco(int timeout)**
**C++ std::vector<node> marco(int timeout)**
**Java ArrayList<Node> marco(int timeout)**
Sends a `marco` message to all nodes, which reply with a Polo message. Upon receiving all responses (those which arrived before the timeout), a collection of the response information is returned.
:param int max_nodes: Maximum number of nodes to be returned. If set to `None`, no limit is applied.
:param list exclude: List of nodes to be excluded from the returned ValueError.
:param int timeout: If set, overrides the default timeout value.
:param int retries: If set to a value greater than 0, retries the *retries* times if the first attempt is unsuccessful
:returns: A list of all responding nodes.
"""
timeout = timeout if timeout else self.timeout
#if sys.version_info[0] < 3:
sendvalue = self.marco_socket.sendto(bytes(json.dumps({"Command": "Marco",
"max_nodes": max_nodes,
"exclude":exclude,
"params":params,
"timeout":timeout,
"group":self.group,
"timeout":timeout}).encode('utf-8')),
('127.0.1.1', 1338))
if sendvalue < 1:
raise MarcoInternalError("Error on sending")
#else:
# self.marco_socket.sendto(bytes(json.dumps({"Command": "Marco",
# "max_nodes": max_nodes,
# "exclude":exclude,
# "params":params,
# "timeout":timeout,
# "group":self.group,
# "timeout":self.timeout}), 'utf-8'),
# ('127.0.1.1', 1338))
error = None
try:
data = self.marco_socket.recv(4096)
except socket.timeout:
error = True
if error:
raise MarcoTimeOutException("No connection to the resolver")
error_parse = None
try:
nodes = json.loads(data.decode('utf-8'))
except ValueError:
error_parse = True
if error_parse:
raise MarcoInternalError("Internal parsing error")
nodes_set = set()
for node in nodes:
n = Node()
n.address = node["Address"]
n.params = node.get("Params", {})
nodes_set.add(n)
return nodes_set
def request_for(self, service, node=None, max_nodes=None, exclude=[], params={}, timeout=None):
"""
**C: struct node * request_for(const char * service)**
**C++: std::vector<std::string> request_for(wchar_t* service)**
**Java: ArrayList<Nodo> request_for(String service)**
Request all nodes offering a service.
:param string service: The name of the service to look for
:param string node: If defined, the function acts as a probe to check if the given node has the service.
:param int timeout: If set to an integer, the resolver will override its local timeout parameter and use this instead for the resolving process.
Please note that the function will block the execution of the thread until the timeout in the Marco configuration file is triggered. Though this should not be a problem for most application, it is worth knowing.
:returns: A list of nodes offering the requested service.
:rvalue: set()
:raise:
:MarcoTimeOutException: If no connection can be made to the local resolver (probably due a failure start of the daemon).
"""
timeout = timeout if timeout else self.timeout
error = None
rvalue = None
try:
rvalue = self.marco_socket.sendto(bytes(json.dumps({"Command": "Request-for",
"Params":service,
"node":node,
"max_nodes":max_nodes,
"exclude":exclude,
"params":params,
"timeout":timeout}).encode('utf-8')), ('127.0.1.1', 1338))
except ValueError as e:
error = True
if error:
raise MarcoTimeOutException("Bad parameters")
if rvalue < 1:
raise MarcoInternalError("Error on communication")
error = None
try:
data, address = self.marco_socket.recvfrom(4096)
except socket.timeout:
error = True
if error:
raise MarcoTimeOutException('No connection to the resolver')
error_parse = None
try:
nodes_arr = json.loads(data.decode('utf-8'))
except ValueError:
error_parse = True
if error_parse:
raise MarcoInternalError("Internal parsing error")
nodes = set()
for node_arr in nodes_arr:
node = Node()
node.address = node_arr["Address"]
node.params = node_arr["Params"]
nodes.add(node)
return nodes
