def read_nbytes_from_data_socket(self, nbytes, flag=socket.MSG_WAITALL):
"""try to read nbytes from data socket, reporting any errors"""
errs = 0
# It is important to specify the list of exceptions to trap here,
# otherwise it would catch a ctrl-c and continue after sys.exit().
try: data = self.data_sock.recv(nbytes, flag)
except(socket.error, socket.herror, socket.gaierror, socket.timeout):
if self.verb > 0: print('** recv() exception on data socket')
errs = 1
if errs: return None
if not data:
if self.verb > 0:
print('** failed recv() of %d bytes from data socket' % nbytes)
return None
if self.verb > 4:
print("++ read %d bytes from socket: %s" \
% (nbytes, UTIL.data_to_hex_str(self.bytes_to_ord(data))))
if len(data) != nbytes:
print('** read only %d of %d bytes from data socket' \
%(len(data),nbytes))
return None
return data
def peek_at_next_bytes(self, nbytes, show=0):
"""peek at and print out the next nbytes of data"""
data = self.read_nbytes_from_data_socket(nbytes,flag=socket.MSG_PEEK)
if not data:
print('** failed to peek ahead')
return
if show or self.verb > 4:
odata = self.bytes_to_ord(data)
print('== peek ahead data: %s' % UTIL.data_to_hex_str(odata))
return data
def write_4byte_data(self, data):
"""write all floats/ints to the serial port"""
if not self.data_port: return
if not self.data_port.isOpen(): return
if self.verb > 4: print('++ writing data to serial port:', data)
dstring = struct.pack('f'*len(data), *data)
if self.swap: UTIL.swap4(dstring)
if self.verb > 5: print('++ hex data to serial port:',
UTIL.data_to_hex_str(self.bytes_to_ord(dstring)))
self.data_port.write(dstring)
del(dstring)
return 0
def socket_has_closed(self):
"""peek ahead for close message"""
data = self.peek_at_next_bytes(g_magic_len)
if not data:
if self.verb > 0: print('** socket has gone dead, restarting...')
return 1
odata = self.bytes_to_ord(data)
if self.verb > 3:
print('++ testing as magic_bye: %s' % UTIL.data_to_hex_str(odata))
# if not magic bye, return a negative
for ind in range(g_magic_len-1):
if odata[ind] != g_magic_bye[ind]: return 0
if self.verb > 0: print('++ found close request for run %d, TRs = %d' \
% (self.nconnects, self.nread))
return 1
def read_magic_hi(self):
"""read and parse magic_hi from data socket, set version
if version > 0, set nextra """
# if self.verb > 3: self.peek_at_next_bytes(8)
data = self.read_nbytes_from_data_socket(g_magic_len)
if not data: return 1
odata = self.bytes_to_ord(data)
if self.verb > 2:
print('++ recieved as magic_hi: %s' % UTIL.data_to_hex_str(odata))
# test whether we have magic, start by ignoring the last byte
for ind in range(g_magic_len-1):
if odata[ind] != g_magic_hi[ind]:
print('** HELLO string is not magic, want %s but have %s' \
% (UTIL.data_to_hex_str(g_magic_hi),UTIL.data_to_hex_str(odata)))
return 1
# now check the last byte for HELLO and version
self.version = odata[g_magic_len-1] - g_magic_hi[g_magic_len-1]
if self.verb > 2:
print('-- hello version is %d' % self.version)
# and deal with the version number
if self.version == 0: pass # we're good to go
elif self.version >= 1 and self.version <= 3:
# ------------------------------------------------------------
# read the next 4-byte int to determine the number of extra data
# values received each TR
# version 1: receive num_extra int over socket
# version 2: receive num_voxels (for 8 vals each) int over socket
ilist = self.read_ints_from_socket(1)
if ilist is None: return 1
if ilist[0] < 0: print('** received invalid num_extra = %d' % ilist[0])
elif self.version == 1:
self.nextra = ilist[0]
elif self.version == 2:
self.nextra = ilist[0] * 8
else: # version = 2
self.nextra = ilist[0]
if self.verb > 2:
print('-- num extra = %d' % self.nextra)
elif self.version == 4:
ilist = self.read_ints_from_socket(2)
if ilist is None: return 1
if len(ilist) < 2:
print('** HELLO version 4: could not read 2 ints from socket')
return 1
if ilist[0] < 0: print('** received invalid num_extra = %d' % ilist[0])
if ilist[1] < 0: print('** received invalid num_ones = %d' % ilist[1])
self.nextra = ilist[0] # number of ROI means
self.nextra2 = ilist[1] # number of mask==1 voxel values
if self.verb > 2:
print('-- num extra = %d, nextra2 = %d' \
% (self.nextra, self.nextra2))
else: # bad, naughty version!
print('** HELLO string trailer is not magic, want %s but have %s' \
% (UTIL.data_to_hex_str(g_magic_hi),UTIL.data_to_hex_str(odata)))
return 1
# todo - show_time()
return 0
