Source code for spinnman.messages.eieio.data_messages.eieio_data_header

# 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 struct
from spinnman.messages.eieio import EIEIOType, EIEIOPrefix
from spinnman.exceptions import SpinnmanInvalidPacketException

_PATTERN_BBHH = struct.Struct("<BBHH")
_PATTERN_BBH = struct.Struct("<BBH")
_PATTERN_BBHI = struct.Struct("<BBHI")
_PATTERN_BBI = struct.Struct("<BBI")
_PATTERN_BB = struct.Struct("<BB")
_PATTERN_HH = struct.Struct("<HH")
_PATTERN_H = struct.Struct("<H")
_PATTERN_HI = struct.Struct("<HI")
_PATTERN_I = struct.Struct("<I")


[docs]class EIEIODataHeader(object): __slots__ = [ "_count", "_eieio_type", "_is_time", "_payload_base", "_prefix", "_prefix_type", "_tag"] def __init__(self, eieio_type, tag=0, prefix=None, prefix_type=EIEIOPrefix.LOWER_HALF_WORD, payload_base=None, is_time=False, count=0): """ EIEIO header for data packets :param EIEIOType eieio_type: the type of message :param int tag: the tag of the message (0 by default) :param prefix: the key prefix of the message or None if not prefixed :type prefix: int or None :param EIEIOPrefix prefix_type: the position of the prefix (upper or lower) :param payload_base: The base payload to be applied, or None if no base payload :type payload_base: int or None :param bool is_time: True if the payloads should be taken to be timestamps, or False otherwise :param int count: Count of the number of items in the packet """ # pylint: disable=too-many-arguments self._eieio_type = eieio_type self._tag = tag self._prefix = prefix self._prefix_type = prefix_type self._payload_base = payload_base self._is_time = is_time self._count = count @property def eieio_type(self): return self._eieio_type @property def tag(self): return self._tag @property def prefix(self): return self._prefix @property def prefix_type(self): return self._prefix_type @property def payload_base(self): return self._payload_base @property def is_time(self): return self._is_time @property def count(self): return self._count @count.setter def count(self, count): self._count = count @property def size(self): return EIEIODataHeader.get_header_size( self._eieio_type, self._prefix is not None, self._payload_base is not None)
[docs] @staticmethod def get_header_size(eieio_type, is_prefix=False, is_payload_base=False): """ Get the size of a header with the given parameters :param EIEIOType eieio_type: the type of message :param bool is_prefix: True if there is a prefix, False otherwise :param bool is_payload_base: True if there is a payload base, False otherwise :return: The size of the header in bytes :rtype: int """ size = 2 if is_prefix: size += 2 if is_payload_base: size += eieio_type.key_bytes return size
[docs] def increment_count(self): self._count += 1
[docs] def reset_count(self): self._count = 0
@property def bytestring(self): """ Get a bytestring of the header :return: The header as a bytestring :rtype: bytes """ # Convert the flags to an int data = 0 # the flag for prefix or not if self._prefix is not None: data |= 1 << 7 # the prefix type data |= self._prefix_type.value << 6 # the flag for payload prefix if self._payload_base is not None: data |= 1 << 5 # the flag for time in payloads if self._is_time: data |= 1 << 4 # The type of the packet data |= self._eieio_type.value << 2 # The tag of the packet data |= self._tag # Convert the remaining data, depending on the various options if self._payload_base is None: if self._prefix is not None: return _PATTERN_BBH.pack(self._count, data, self._prefix) return _PATTERN_BB.pack(self._count, data) if (self._eieio_type == EIEIOType.KEY_PAYLOAD_16_BIT or self._eieio_type == EIEIOType.KEY_16_BIT): if self._prefix is not None: return _PATTERN_BBHH.pack( self._count, data, self._prefix, self._payload_base) return _PATTERN_BBH.pack(self._count, data, self._payload_base) if (self._eieio_type == EIEIOType.KEY_PAYLOAD_32_BIT or self._eieio_type == EIEIOType.KEY_32_BIT): if self._prefix is not None: return _PATTERN_BBHI.pack( self._count, data, self._prefix, self._payload_base) return _PATTERN_BBI.pack(self._count, data, self._payload_base) raise SpinnmanInvalidPacketException( "EIEIODataMessage", "unexpected EIEIO type code")
[docs] @staticmethod def from_bytestring(data, offset): """ Read an eieio data header from a bytestring :param bytes data: The bytestring to be read :param int offset: The offset at which the data starts :return: an EIEIO header :rtype: EIEIODataHeader """ (count, header_data) = _PATTERN_BB.unpack_from(data, offset) # Read the flags in the header prefix_flag = (header_data >> 7) & 1 format_flag = (header_data >> 6) & 1 payload_prefix_flag = (header_data >> 5) & 1 payload_is_timestamp = (header_data >> 4) & 1 message_type = (header_data >> 2) & 3 tag = header_data & 3 # Check for command header if prefix_flag == 0 and format_flag == 1: raise SpinnmanInvalidPacketException( "EIEIODataHeader", "The header indicates that this is a command header") # Convert the flags into types # pylint: disable=no-value-for-parameter eieio_type = EIEIOType(message_type) prefix_type = EIEIOPrefix(format_flag) prefix = None payload_prefix = None if payload_prefix_flag == 1: if (eieio_type == EIEIOType.KEY_16_BIT or eieio_type == EIEIOType.KEY_PAYLOAD_16_BIT): if prefix_flag == 1: (prefix, payload_prefix) = _PATTERN_HH.unpack_from( data, offset + 2) else: payload_prefix = _PATTERN_H.unpack_from( data, offset + 2)[0] elif (eieio_type == EIEIOType.KEY_32_BIT or eieio_type == EIEIOType.KEY_PAYLOAD_32_BIT): if prefix_flag == 1: (prefix, payload_prefix) = _PATTERN_HI.unpack_from( data, offset + 2) else: payload_prefix = _PATTERN_I.unpack_from( data, offset + 2)[0] else: if prefix_flag == 1: prefix = _PATTERN_H.unpack_from(data, offset + 2)[0] return EIEIODataHeader( eieio_type=eieio_type, tag=tag, prefix=prefix, prefix_type=prefix_type, payload_base=payload_prefix, is_time=bool(payload_is_timestamp), count=count)
def __str__(self): return ("EIEIODataHeader:prefix={}:prefix_type={}:payload_base={}:" "is_time={}:type={}:tag={}:count={}".format( self._prefix, self._prefix_type, self._payload_base, self._is_time, self._eieio_type.value, self._tag, self._count)) def __repr__(self): return self.__str__()