class SafeDict(object):
def __init__(self):
self.lock = RWLock()
self.dict = {}
def __str__(self):
self.lock.acquire_read()
ret = str(self.dict)
self.lock.release_read()
return ret
def add_to_dict(self, key, value):
self.lock.acquire_write()
self.dict[key] = value
self.lock.release_write()
def get_from_dict(self, key):
ret = None
self.lock.acquire_read()
if key in self.dict:
ret = self.dict[key]
self.lock.release_read()
return ret
class QuantumStorage(object):
"""
An object which stores qubits.
"""
STORAGE_LIMIT_ALL = 1
STORAGE_LIMIT_PER_HOST = 2
STORAGE_LIMIT_INDIVIDUALLY_PER_HOST = 3
def __init__(self):
# _host_dict stores host_id -> array with qubits of the host.
self._host_dict = {}
# _qubit_dict stores qubit_id -> dict Host_id -> Qubit objects with this id.
self._qubit_dict = {}
# _purpose_dict stores qubit_id -> dict Host_id -> Purpose belonging to
# the Qubit with the same Host and ID.
self._purpose_dict = {}
self._storage_mode = QuantumStorage.STORAGE_LIMIT_INDIVIDUALLY_PER_HOST
self._storage_limits_per_host = {}
self._amount_qubits_stored_per_host = {}
self._default_storage_limit_per_host = -1
self._storage_limit = -1
self._amount_qubit_stored = 0
# read write lock, for threaded access
self.lock = RWLock()
self.logger = Logger.get_instance()
# for tracking pending requests
# dictionary tracks the request made by a pending request.
self._pending_request_dict = {}
# Determines a unique ID for a pending request.
self._request_id = 0
# Amount of pending requests
self._amount_pending_requests = 0
def __str__(self):
out = ""
out += "Quantum storage with the properties:\nstorage mode: %d\nstorage limit: %d\n" % (
self._storage_mode, self._storage_limit)
out += "Host dictionary is:\n"
out += "; ".join([
str(key) + ":" + str([v.id for v in value])
for key, value in self._host_dict.items()
])
out += "\n"
out += "Qubit dictionary is:\n"
out += "; ".join([
str(key) + ":" + str(value)
for key, value in self._qubit_dict.items()
])
out += "\n"
out += "Purpose dictionary is:\n"
out += "; ".join([
str(key) + ":" + str(value)
for key, value in self._purpose_dict.items()
])
out += "\n"
return out
@property
def storage_limit(self):
return self._storage_limit
@storage_limit.setter
def storage_limit(self, new_limit):
"""
Set a new storage limit for the storage. The implementations depends on
the storage mode.
Args:
new_limit (int): The new max amount of qubit.
"""
if self._storage_mode == QuantumStorage.STORAGE_LIMIT_ALL:
self._storage_limit = new_limit
elif self._storage_mode == QuantumStorage.STORAGE_LIMIT_PER_HOST:
self._storage_limit = new_limit
elif self._storage_mode == QuantumStorage.STORAGE_LIMIT_INDIVIDUALLY_PER_HOST:
self._default_storage_limit_per_host = new_limit
for id_ in list(self._storage_limits_per_host):
self._storage_limits_per_host[id_] = new_limit
else:
raise ValueError(
"Internal Value Error, this storage mode does not exist.")
@property
def storage_limit_mode(self):
return self._storage_mode
@storage_limit_mode.setter
def storage_limit_mode(self, new_mode):
self._storage_mode = new_mode
@property
def amount_qubits_stored(self):
return self._amount_qubit_stored
def amount_qubits_stored_with_host(self, host_id):
return self._amount_qubits_stored_per_host[host_id]
def set_storage_limit_with_host(self, new_limit, host_id):
"""
Set a new storage limit for the storage. The implementations depends on
the storage mode.
Args:
new_limit (int): The new max amount of qubit.
host_id (str): optional, if given, and the storage mode is
STORAGE_LIMIT_INDIVIDUALLY_PER_HOST, the limit is only
set for this specific host.
"""
if self._storage_mode == QuantumStorage.STORAGE_LIMIT_INDIVIDUALLY_PER_HOST:
if host_id is None:
raise ValueError("Host ID must be given in this storage mode")
else:
self._storage_limits_per_host[host_id] = new_limit
else:
raise ValueError(
"Internal Value Error, this storage mode does not exist.")
def reset_storage(self):
"""
Reset the quantum storage.
"""
for host in self._host_dict:
self.reset_qubits_from_host(host)
def release_storage(self):
"""
Releases all qubits in this storage. The storage is not
usable anymore after this function has been called.
"""
self.lock.acquire_write()
for q in self._qubit_dict.values():
for ele in q.values():
ele.release()
# do not release write, storage not usable anymore
def check_qubit_from_host_exists(self, from_host_id, purpose=None):
"""
Check if a qubit from a host exists in this quantum storage.
Args:
from_host_id (str): The host id of the host from which the qubit is from.
purpose (int): Optional, purpose of the qubit which should exist.
Returns:
(bool): True, if such a qubit is in the storage, false if not.
"""
self.lock.acquire_write()
if from_host_id not in self._host_dict:
self.lock.release_write()
return False
for q in self._host_dict[from_host_id]:
if self._check_qubit_in_system(q, from_host_id, purpose):
self.lock.release_write()
return True
self.lock.release_write()
return False
def get_qubit_by_id(self, q_id):
"""
Return the qubit that has the id *q_id*
Args:
q_id (str): The ID of the qubit
Returns:
(Qubit): The qubit with the id *q_id* or None if it does not exist
"""
if q_id in self._qubit_dict:
return list(self._qubit_dict[q_id].values())[0]
return None
def change_qubit_id(self, from_host_id, new_id, old_id=None):
"""
Changes the ID of a qubit. If the ID is not given, a random
qubit which is from a host is changed to the new id.
Args:
from_host_id (str): The ID of the owner
new_id (str): The ID to change to
old_id (str): The old ID
Returns:
(str): The new ID
"""
new_id = str(new_id)
self.lock.acquire_write()
if old_id is not None:
old_id = str(old_id)
qubit, purpose = self._pop_qubit_with_id_and_host_from_qubit_dict(
old_id, from_host_id)
if qubit is not None:
qubit.id = new_id
self._add_qubit_to_qubit_dict(qubit, purpose, from_host_id)
else:
if from_host_id in self._host_dict and self._host_dict[
from_host_id]:
qubit = self._host_dict[from_host_id][0]
old_id = qubit.id
_, purpose = self._pop_qubit_with_id_and_host_from_qubit_dict(
old_id, from_host_id)
qubit.id = new_id
self._add_qubit_to_qubit_dict(qubit, purpose, from_host_id)
self.lock.release_write()
return old_id
def add_qubit_from_host(self, qubit, purpose, from_host_id):
"""
Adds a qubit which has been received from a host.
Args:
qubit (Qubit): qubit which should be stored.
from_host_id (str): Id of the Host from whom the qubit has
been received.
purpose (str): Purpose of the Qubit, for example EPR or data.
"""
self.lock.acquire_write()
if self._check_qubit_in_system(qubit, from_host_id, purpose=purpose):
self.logger.log("Qubit with id %s, purpose %s and from host %s"
" already in storage" %
(qubit.id, purpose, from_host_id))
raise ValueError("Qubit with these parameters already in storage!")
if from_host_id not in self._host_dict:
self._add_new_host(from_host_id)
if not self._increase_qubit_counter(from_host_id):
qubit.release()
self.lock.release_write()
return
self._host_dict[from_host_id].append(qubit)
self._add_qubit_to_qubit_dict(qubit, purpose, from_host_id)
# Check if a Qubit of one of the callbacks has arrived
self._check_all_requests()
self.lock.release_write()
def get_all_qubits_from_host(self,
from_host_id,
purpose=None,
remove=False):
"""
Get all Qubits from a specific host id.
These qubits are not removed from storage!
Args:
from_host_id (str): The host who the qubits are from
purpose (int): The purpose of the qubits
remove (bool): Also remove from storage
Returns:
(list): The list of qubits
"""
if from_host_id in self._host_dict:
out = []
self.lock.acquire_write()
flag = False
for q in self._host_dict[from_host_id]:
if self._check_qubit_in_system(q, from_host_id, purpose):
if not remove:
out.append(q)
else:
flag = True
if remove:
break
if not flag and remove:
num_qubits = len(self._host_dict[from_host_id])
for _ in range(num_qubits):
out.append(
self._get_qubit_from_host(from_host_id,
purpose=purpose))
self.lock.release_write()
return out
return []
def reset_qubits_from_host(self, from_host_id, purpose=None):
"""
Remove all stored qubits from the host *from_host_id*.
Args:
from_host_id (str): The host who the qubits are from
purpose (int):
"""
self.lock.acquire_write()
if from_host_id in self._host_dict:
for q in self._host_dict[from_host_id]:
if self._check_qubit_in_system(q, from_host_id, purpose):
self._get_qubit_from_host(from_host_id, purpose=purpose)
self.lock.release_write()
def _check_all_requests(self):
"""
Checks if any of the pending requests is now fulfilled.
Returns:
If a request is fulfilled, the request is handled and the function
returns the qubit of this request.
"""
for req_id, args in self._pending_request_dict.items():
ret = self._get_qubit_from_host(args[1], args[2], args[3])
if ret is not None:
args[0].put(ret)
self._remove_request(req_id)
return ret
def _add_request(self, args):
"""
Adds a new request to the quantum storage. If a new qubit arrives, it
is checked if the request for the qubit is satisfied.
Args:
args (list): [Queue, from_host_id, q_id, purpose]
"""
self._pending_request_dict[self._request_id] = args
self._request_id += 1
self._amount_pending_requests += 1
return self._request_id
def _remove_request(self, req_id):
"""
Removes a pending request from the request dict.
Args:
req_id (int): The id of the request to remove.
"""
if req_id in self._pending_request_dict:
del self._pending_request_dict[req_id]
self._amount_pending_requests -= 1
def get_qubit_from_host(self,
from_host_id,
q_id=None,
purpose=None,
wait=0):
"""
Returns next qubit which has been received from a host. If the qubit has
not been receives yet, the thread is blocked for a maxiumum of the wait time,
till the qubit arrives (The default is 0). If the id is given, the exact qubit with the id
is returned, or None if it does not exist.
The qubit is removed from the quantum storage.
Args:
from_host_id (str): Host id from who the qubit has been received.
q_id (str): Optional Id, to return the exact qubit with the Id.
purpose (str): Optional, purpose of the Qubit.
wait (int): Default is 0. The maximum blocking time. -1 if blocking forever.
Returns:
(bool): If such a qubit exists, it returns the qubit. Otherwise, None
is returned.
"""
# Block forever if wait is -1
if wait == -1:
wait = None
self.lock.acquire_write()
ret = self._get_qubit_from_host(from_host_id, q_id, purpose)
if ret is not None or wait == 0:
self.lock.release_write()
return ret
q = queue.Queue()
args = [q, from_host_id, q_id, purpose]
req_id = self._add_request(args)
self.lock.release_write()
ret = None
try:
ret = q.get(timeout=wait)
except queue.Empty:
pass
if ret is None:
self.lock.acquire_write()
self._remove_request(req_id)
self.lock.release_write()
return ret
def _get_qubit_from_host(self, from_host_id, q_id=None, purpose=None):
if q_id is not None:
qubit = self._pop_qubit_with_id_and_host_from_qubit_dict(
q_id, from_host_id, purpose=purpose)
if qubit is not None:
qubit, purp = qubit
if from_host_id not in self._host_dict or \
qubit not in self._host_dict[from_host_id]:
# Qubit with the ID exists, but does not belong to the host requested
self._add_qubit_to_qubit_dict(qubit, purp, from_host_id)
return None
self._host_dict[from_host_id].remove(qubit)
self._decrease_qubit_counter(from_host_id)
return qubit
if from_host_id not in self._host_dict:
return None
if self._host_dict[from_host_id]:
# check purposes of all qubits
for _ in range(len(self._host_dict[from_host_id])):
qubit = self._host_dict[from_host_id].pop(0)
out = self._pop_qubit_with_id_and_host_from_qubit_dict(
qubit.id, from_host_id, purpose=purpose)
if out is not None:
self._decrease_qubit_counter(from_host_id)
return out[0]
self._host_dict[from_host_id].append(qubit)
return None
def _pop_qubit_with_id_and_host_from_qubit_dict(self,
q_id,
from_host_id,
purpose=None):
def _pop_purpose_from_purpose_dict():
nonlocal q_id, from_host_id
if q_id not in self._purpose_dict:
return None
pur = self._purpose_dict[q_id].pop(from_host_id, None)
if pur is not None:
if not self._purpose_dict[q_id]:
del self._purpose_dict[q_id]
return pur
return None
purp = _pop_purpose_from_purpose_dict()
if purp is not None:
if purpose is None or purpose == purp:
qubit = self._qubit_dict[q_id].pop(from_host_id, None)
if qubit is not None:
if not self._qubit_dict[q_id]:
del self._qubit_dict[q_id]
return qubit, purp
else:
if q_id not in self._purpose_dict:
self._purpose_dict[q_id] = {}
self._purpose_dict[q_id][from_host_id] = purp
return None
def _add_qubit_to_qubit_dict(self, qubit, purpose, from_host_id):
def _add_purpose_to_purpose_dict(q_id):
nonlocal purpose, from_host_id
if q_id not in self._purpose_dict:
self._purpose_dict[q_id] = {}
self._purpose_dict[q_id][from_host_id] = purpose
if qubit.id not in self._qubit_dict:
self._qubit_dict[qubit.id] = {}
self._qubit_dict[qubit.id][from_host_id] = qubit
_add_purpose_to_purpose_dict(qubit.id)
def _add_new_host(self, host_id):
if host_id not in self._host_dict:
self._host_dict[host_id] = []
if host_id not in self._storage_limits_per_host:
self._storage_limits_per_host[
host_id] = self._default_storage_limit_per_host
self._amount_qubits_stored_per_host[host_id] = 0
def _check_qubit_in_system(self, qubit, from_host_id, purpose=None):
"""
True if qubit with same parameters already in the systems
Args:
qubit (Qubit): The qubit in question
from_host_id (str): The ID of the sending host
purpose (int): Qubit's purpose
Returns:
(bool): If the qubit is in the system.
"""
if qubit.id in self._qubit_dict and \
from_host_id in self._qubit_dict[qubit.id]:
if purpose is None or (
purpose == self._purpose_dict[qubit.id][from_host_id]):
return True
return False
def _check_memory_limits(self, host_id):
"""
Checks if another qubit can be added to the storage.
Args:
host_id (str): The host_id the qubit should be added to.
Returns:
True if no storage limit has been reached, False if a memory
limit has occurred.
"""
if self._storage_mode == QuantumStorage.STORAGE_LIMIT_ALL:
if self._storage_limit == -1:
return True
if self._storage_limit <= self._amount_qubit_stored:
return False
else:
return True
elif self._storage_mode == QuantumStorage.STORAGE_LIMIT_PER_HOST:
if self._storage_limit == -1:
return True
if self._storage_limit <= self._amount_qubits_stored_per_host[
host_id]:
return False
else:
return True
elif self._storage_mode == QuantumStorage.STORAGE_LIMIT_INDIVIDUALLY_PER_HOST:
if self._storage_limits_per_host[host_id] == -1:
return True
if self._storage_limits_per_host[
host_id] <= self._amount_qubits_stored_per_host[host_id]:
return False
else:
return True
else:
raise ValueError(
"Internal Value Error, this storage mode does not exist.")
def _increase_qubit_counter(self, host_id):
"""
Checks if the qubit counter can be increased, because of memory limits,
and increases the counter.
Args:
host_id (str): From who the qubit comes from.
Returns:
True, if the counter could be increased, False if not.
"""
if not self._check_memory_limits(host_id):
return False
self._amount_qubits_stored_per_host[host_id] += 1
self._amount_qubit_stored += 1
return True
def _reset_qubit_counter(self, host_id):
"""
Args:
host_id (str):
Returns:
(bool): True, if the counter could be decreased, False if not.
"""
if self._amount_qubits_stored_per_host[host_id] <= 0 or \
self._amount_qubit_stored <= 0:
return False
num_qubits = self._amount_qubits_stored_per_host[host_id]
self._amount_qubits_stored_per_host[host_id] = 0
self._amount_qubit_stored -= num_qubits
def _decrease_qubit_counter(self, host_id):
"""
Checks if the qubit counter can be decreased
and decreases the counter.
Args:
host_id (str): From who the qubit comes from.
Returns:
(bool): True, if the counter could be decreased, False if not.
"""
if self._amount_qubits_stored_per_host[host_id] <= 0 or \
self._amount_qubit_stored <= 0:
return False
self._amount_qubits_stored_per_host[host_id] -= 1
self._amount_qubit_stored -= 1
class QubitCollection(object):
def __init__(self, name):
# initialize as a qubit in state |0>
self._rwlock = RWLock()
self.N = 1
self._qubit_names = [name]
self.data = qutip.qutip.fock_dm(2, 0)
def add_qubit(self, qubit):
"""
Calculates the tensor product using the implementation
of QuTip.
Modified vesion of qutip tensor function,
See http://qutip.org/docs/4.0.2/modules/qutip/tensor.html
"""
self._lock()
self.data = qutip.tensor(self.data, qubit.data)
self.N = self.N + qubit.N
self._qubit_names = self._qubit_names + qubit._qubit_names
self._unlock()
def apply_single_gate(self, gate, qubit_name):
if not isinstance(gate, qutip.Qobj):
raise TypeError("Gate has to be of type Qobject.")
self._lock()
target = self._qubit_names.index(qubit_name)
gate = qutip.gate_expand_1toN(gate, self.N, target)
self.data = gate * self.data * gate.dag()
self._unlock()
def apply_double_gate(self, gate, control_name, target_name):
if not isinstance(gate, qutip.Qobj):
raise TypeError("Gate has to be of type Qobject.")
self._lock()
control = self._qubit_names.index(control_name)
target = self._qubit_names.index(target_name)
gate = qutip.gate_expand_2toN(gate, self.N, control, target)
self.data = gate * self.data * gate.dag()
self._unlock()
def measure(self, qubit_name, non_destructive):
res = None
M_0 = qutip.fock(2, 0).proj()
M_1 = qutip.fock(2, 1).proj()
self._lock()
target = self._qubit_names.index(qubit_name)
if self.N > 1:
M_0 = qutip.gate_expand_1toN(M_0, self.N, target)
M_1 = qutip.gate_expand_1toN(M_1, self.N, target)
pr_0 = qutip.expect(M_0, self.data)
pr_1 = qutip.expect(M_1, self.data)
outcome = int(np.random.choice([0, 1], 1, p=[pr_0, pr_1]))
if outcome == 0:
self.data = M_0 * self.data * M_0.dag() / pr_0
res = 0
else:
# M_1 = qutip.gate_expand_1toN(M_1, self.N, target)
self.data = M_1 * self.data * M_1.dag() / pr_1
res = 1
if non_destructive is False:
i_list = [x for x in range(self.N)]
i_list.remove(target)
self._qubit_names.remove(qubit_name)
self.N = self.N - 1
if len(i_list) > 0:
self.data = self.data.ptrace(i_list)
else:
self.data = qutip.Qobj()
self._unlock()
return res
def _lock(self):
self._rwlock.acquire_write()
def _unlock(self):
self._rwlock.release_write()
class ClassicalStorage(object):
GET_NEXT = 1
GET_ALL = 2
GET_WITH_SEQ_NUM = 3
"""
A classical storage for messages.
"""
def __init__(self):
self._host_to_msg_dict = {}
self._host_to_read_index = {}
# read write lock, for threaded access
self._lock = RWLock()
# for tracking pending requests
# dictionary tracks the request made by a pending request.
self._pending_request_dict = {}
# Determines a unique ID for a pending request.
self._request_id = 0
# Amount of pending requests
self._amount_pending_requests = 0
def _check_all_requests(self):
"""
Checks if any of the pending requests is now fulfilled.
Returns:
If a request is fulfilled, the request is handled and the function
returns the message of this request.
"""
for req_id, args in self._pending_request_dict.items():
ret = None
if args[2] == ClassicalStorage.GET_NEXT:
ret = self._get_next_from_sender(args[1])
elif args[2] == ClassicalStorage.GET_ALL:
ret = self._get_all_from_sender(args[1])
elif args[2] == ClassicalStorage.GET_WITH_SEQ_NUM:
ret = self._get_with_seq_num_from_sender(args[1], args[3])
else:
raise ValueError("Internal Error, this request does not exist!")
if ret is not None:
args[0].put(ret)
self._remove_request(req_id)
return ret
def _add_request(self, args):
"""
Adds a new request to the classical storage. If a new message arrives, it
is checked if the request for the qubit is satisfied.
Args:
args (list): [Queue, from_host_id, type, ...]
Returns:
(int): ID of the request
"""
self._pending_request_dict[self._request_id] = args
self._request_id += 1
self._amount_pending_requests += 1
return self._request_id
def _remove_request(self, req_id):
"""
Removes a pending request from the request dict.
Args:
req_id (int): The id of the request to remove.
"""
if req_id in self._pending_request_dict:
del self._pending_request_dict[req_id]
self._amount_pending_requests -= 1
def empty(self):
"""
Empty the classical storage.
"""
self._lock.acquire_write()
self._host_to_msg_dict = {}
self._host_to_read_index = {}
self._lock.release_write()
def _add_new_host_id(self, host_id):
"""
Add a new host to the storage.
Args:
host_id (str): The host ID to store.
"""
self._host_to_msg_dict[host_id] = []
self._host_to_read_index[host_id] = 0
def remove_all_ack(self, from_sender=None):
"""
Removes all ACK messages stored. If from sender is given, only ACKs from
this sender are removed.
Args:
from_sender (String): Host id of the sender, whos ACKs should be delted.
"""
self._lock.acquire_write()
def delete_all_ack_for_sender(sender_id):
for c, msg in enumerate(self._host_to_msg_dict[sender_id]):
if msg.content == Constants.ACK:
del self._host_to_msg_dict[sender_id][c]
if from_sender is None:
for sender in list(self._host_to_msg_dict):
delete_all_ack_for_sender(sender)
elif from_sender in self._host_to_msg_dict:
delete_all_ack_for_sender(from_sender)
self._lock.release_write()
# TODO: refactor to "add_msg"
def add_msg_to_storage(self, message):
"""
Adds a message to the storage.
"""
sender_id = message.sender
self._lock.acquire_write()
if sender_id not in list(self._host_to_msg_dict):
self._add_new_host_id(sender_id)
self._host_to_msg_dict[sender_id].append(message)
self._check_all_requests()
self._lock.release_write()
def get_all_from_sender(self, sender_id, wait=0):
"""
Get all stored messages from a sender. If delete option is set,
the returned messages are removed from the storage.
Args:
sender_id (String): The host id of the host.
wait (int): Default is 0. The maximum blocking time. -1 to block forever.
Returns:
List of messages of the sender. If there are none, an empty list is
returned.
"""
# Block forever if wait is -1
if wait == -1:
wait = None
self._lock.acquire_write()
msg = self._get_all_from_sender(sender_id)
if msg is not None or wait == 0:
self._lock.release_write()
return msg if msg is not None else []
q = queue.Queue()
request = [q, sender_id, ClassicalStorage.GET_ALL]
req_id = self._add_request(request)
self._lock.release_write()
try:
msg = q.get(timeout=wait)
except queue.Empty:
pass
if msg is None:
self._lock.acquire_write()
self._remove_request(req_id)
self._lock.release_write()
return []
return msg
def _get_all_from_sender(self, sender_id):
if sender_id in list(self._host_to_msg_dict):
return self._host_to_msg_dict[sender_id]
return None
def get_next_from_sender(self, sender_id, wait=0):
"""
Gets the next, unread, message from the sender. If there is no message
yet, it is waited for the waiting time till a message is arrived. If
there is still no message, than None is returned.
Args:
sender_id (String): The sender id of the message to get.
wait (int): Default is 0. The maximum blocking time. -1 to block forever.
Returns:
Message object, if such a message exists, or none.
"""
# Block forever if wait is -1
if wait == -1:
wait = None
self._lock.acquire_write()
next_msg = self._get_next_from_sender(sender_id)
if next_msg is not None or wait == 0:
self._lock.release_write()
return next_msg
q = queue.Queue()
request = [q, sender_id, ClassicalStorage.GET_NEXT]
req_id = self._add_request(request)
self._lock.release_write()
try:
next_msg = q.get(timeout=wait)
except queue.Empty:
pass
if next_msg is None:
self._lock.acquire_write()
self._remove_request(req_id)
self._lock.release_write()
return next_msg
def _get_next_from_sender(self, sender_id):
if sender_id not in list(self._host_to_msg_dict):
return None
if len(self._host_to_msg_dict[sender_id]) <= self._host_to_read_index[sender_id]:
return None
msg = self._host_to_msg_dict[sender_id][self._host_to_read_index[sender_id]]
self._host_to_read_index[sender_id] += 1
return msg
def get_with_seq_num_from_sender(self, sender_id, seq_num, wait=0):
"""
Gets the next, unread, message from the sender. If there is no message
yet, it is waited for the waiting time till a message is arrived. If
there is still no message, than None is returned.
Args:
sender_id (String): The sender id of the message to get.
wait (int): Default is 0. The maximum blocking time. -1 to block forever.
Returns:
Message object, if such a message exists, or none.
"""
# Block forever if wait is -1
if wait == -1:
wait = None
self._lock.acquire_write()
next_msg = self._get_with_seq_num_from_sender(sender_id, seq_num)
if next_msg is not None or wait == 0:
self._lock.release_write()
return next_msg
q = queue.Queue()
request = [q, sender_id, ClassicalStorage.GET_NEXT, seq_num]
req_id = self._add_request(request)
self._lock.release_write()
try:
next_msg = q.get(timeout=wait)
except queue.Empty:
pass
if next_msg is None:
self._lock.acquire_write()
self._remove_request(req_id)
self._lock.release_write()
return next_msg
def _get_with_seq_num_from_sender(self, sender_id, seq_num):
if sender_id not in list(self._host_to_msg_dict):
return None
if len(self._host_to_msg_dict[sender_id]) <= seq_num:
return None
msg = self._host_to_msg_dict[sender_id][seq_num]
return msg
def get_all(self):
"""
Get all Messages as a list.
Returns:
(list) messages: All Messages as a list.
"""
self._lock.acquire_write()
ret = []
for host_id in list(self._host_to_msg_dict):
ret += self._host_to_msg_dict[host_id]
self._lock.release_write()
return ret