Source code for spinn_front_end_common.interface.buffer_management.storage_objects.buffered_sending_region
# Copyright (c) 2017-2019 The University of Manchester
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import bisect
import math
from spinnman.messages.eieio.command_messages import HostSendSequencedData
from spinnman.messages.eieio.data_messages import EIEIODataHeader
from spinnman.messages.eieio import EIEIOType
from spinnman.constants import UDP_MESSAGE_MAX_SIZE
_HEADER_SIZE = EIEIODataHeader.get_header_size(
EIEIOType.KEY_32_BIT, is_payload_base=True)
# The number of bytes in each key to be sent
_N_BYTES_PER_KEY = EIEIOType.KEY_32_BIT.key_bytes # @UndefinedVariable
# The number of keys allowed (different from the actual number as there is
# an additional header)
_N_KEYS_PER_MESSAGE = (UDP_MESSAGE_MAX_SIZE -
(HostSendSequencedData.get_min_packet_length() +
_HEADER_SIZE)) // _N_BYTES_PER_KEY
def get_n_bytes(n_keys):
""" Get the number of bytes used by a given number of keys.
:param n_keys: The number of keys
:type n_keys: int
"""
# Get the total number of messages
n_messages = int(math.ceil(float(n_keys) / _N_KEYS_PER_MESSAGE))
# Add up the bytes
return ((_HEADER_SIZE * n_messages) +
(n_keys * _N_BYTES_PER_KEY))
[docs]class BufferedSendingRegion(object):
""" A set of keys to be sent at given timestamps for a given region of\
data. Note that keys must be added in timestamp order or else an\
exception will be raised.
"""
__slots__ = [
#: A dictionary of timestamp -> list of keys
"_buffer",
#: A list of timestamps
"_timestamps",
#: The current position in the list of timestamps
"_current_timestamp_pos"
]
def __init__(self):
self._buffer = dict()
self._timestamps = list()
self._current_timestamp_pos = 0
[docs] def add_key(self, timestamp, key):
""" Add a key to be sent at a given time.
:param timestamp: The time at which the key is to be sent
:type timestamp: int
:param key: The key to send
:type key: int
"""
if timestamp not in self._buffer:
bisect.insort(self._timestamps, timestamp)
self._buffer[timestamp] = list()
self._buffer[timestamp].append(key)
[docs] def add_keys(self, timestamp, keys):
""" Add a set of keys to be sent at the given time.
:param timestamp: The time at which the keys are to be sent
:type timestamp: int
:param keys: The keys to send
:type keys: iterable(int)
"""
for key in keys:
self.add_key(timestamp, key)
@property
def n_timestamps(self):
""" The number of timestamps available.
:rtype: int
"""
return len(self._timestamps)
@property
def timestamps(self):
""" The timestamps for which there are keys.
:rtype: iterable(int)
"""
return self._timestamps
[docs] def get_n_keys(self, timestamp):
""" Get the number of keys for a given timestamp.
:param timestamp: \
the time stamp to check if there's still keys to transmit
"""
if timestamp in self._buffer:
return len(self._buffer[timestamp])
return 0
@property
def is_next_timestamp(self):
""" Determines if the region is empty.
True if the region is empty, false otherwise.
:rtype: bool
"""
return self._current_timestamp_pos < len(self._timestamps)
@property
def next_timestamp(self):
""" The next timestamp of the data to be sent, or None if no more data.
:rtype: int or None
"""
if self.is_next_timestamp:
return self._timestamps[self._current_timestamp_pos]
return None
[docs] def is_next_key(self, timestamp):
""" Determine if there is another key for the given timestamp.
:param timestamp: \
the time stamp to check if there's still keys to transmit
:rtype: bool
"""
if timestamp in self._buffer:
return bool(self._buffer[timestamp])
return False
@property
def next_key(self):
""" The next key to be sent.
:rtype: int
"""
next_timestamp = self.next_timestamp
keys = self._buffer[next_timestamp]
key = keys.pop()
if not keys:
del self._buffer[next_timestamp]
self._current_timestamp_pos += 1
return key
@property
def current_timestamp(self):
""" The current timestamp in the iterator.
"""
return self._current_timestamp_pos
[docs] def rewind(self):
""" Rewind the buffer to initial position.
"""
self._current_timestamp_pos = 0
[docs] def clear(self):
""" Clears the buffer.
"""
self._buffer = dict()
self._timestamps = list()
self._current_timestamp_pos = 0