def serializer_generator(msg_context, spec, serialize, is_numpy):
"""
Python generator that yields un-indented python code for
(de)serializing MsgSpec. The code this yields is meant to be
included in a class method and cannot be used
standalone. serialize_fn_generator and deserialize_fn_generator
wrap method to provide appropriate class field initializations.
:param serialize: if True, yield serialization
code. Otherwise, yield deserialization code. ``bool``
:param is_numpy: if True, generate serializer code for numpy datatypes instead of Python lists. ``bool``
"""
# Break spec into chunks of simple (primitives) vs. complex (arrays, etc...)
# Simple types are batch serialized using the python struct module.
# Complex types are individually serialized
if spec is None:
raise MsgGenerationException("spec is none")
names, types = spec.names, spec.types
if serialize and not len(names): #Empty
yield "pass"
return
_max_chunk = 255
# iterate through types. whenever we encounter a non-simple type,
# yield serializer for any simple types we've encountered until
# then, then yield the complex type serializer
curr = 0
for (i, full_type) in enumerate(types):
if not is_simple(full_type):
if i != curr: #yield chunk of simples
for _start in range(curr, i, _max_chunk):
_end = min(_start + _max_chunk, i)
for y in simple_serializer_generator(msg_context, spec, _start, _end, serialize):
yield y
curr = i+1
for y in complex_serializer_generator(msg_context, spec.package, full_type, names[i], serialize, is_numpy):
yield y
if curr < len(types): #yield rest of simples
for _start in range(curr, len(types), _max_chunk):
_end = min(_start + _max_chunk, len(types))
for y in simple_serializer_generator(msg_context, spec, _start, _end, serialize):
yield y
def check_type(field_name, field_type, field_val):
"""
Dynamic type checker that maps ROS .msg types to python types and
verifies the python value. check_type() is not designed to be
fast and is targeted at error diagnosis. This type checker is not
designed to run fast and is meant only for error diagnosis.
:param field_name: ROS .msg field name, ``str``
:param field_type: ROS .msg field type, ``str``
:param field_val: field value, ``Any``
:raises: :exc:`SerializationError` If typecheck fails
"""
if is_simple(field_type):
# check sign and width
if field_type in ['byte', 'int8', 'int16', 'int32', 'int64']:
if type(field_val) not in [long, int]:
raise SerializationError('field %s must be an integer type' %
field_name)
maxval = int(math.pow(2, _widths[field_type] - 1))
if field_val >= maxval or field_val <= -maxval:
raise SerializationError(
'field %s exceeds specified width [%s]' %
(field_name, field_type))
elif field_type in ['char', 'uint8', 'uint16', 'uint32', 'uint64']:
if type(field_val) not in [long, int] or field_val < 0:
raise SerializationError(
'field %s must be unsigned integer type' % field_name)
maxval = int(math.pow(2, _widths[field_type]))
if field_val >= maxval:
raise SerializationError(
'field %s exceeds specified width [%s]' %
(field_name, field_type))
elif field_type == 'bool':
if field_val not in [True, False, 0, 1]:
raise SerializationError('field %s is not a bool' %
(field_name))
elif field_type == 'string':
if sys.hexversion > 0x03000000:
if type(field_val) == str:
try:
field_val.encode('ascii')
except UnicodeEncodeError:
raise SerializationError('field %s is a non-ascii string' %
field_name)
elif not type(field_val) == bytes:
raise SerializationError(
'field %s must be of type bytes or an ascii string' %
field_name)
else:
if type(field_val) == unicode:
raise SerializationError(
'field %s is a unicode string instead of an ascii string' %
field_name)
elif not isstring(field_val):
raise SerializationError('field %s must be of type str' %
field_name)
elif field_type == 'time':
if not isinstance(field_val, Time):
raise SerializationError('field %s must be of type Time' %
field_name)
elif field_type == 'duration':
if not isinstance(field_val, Duration):
raise SerializationError('field %s must be of type Duration' %
field_name)
elif field_type.endswith(']'): # array type
# use index to generate error if '[' not present
base_type = field_type[:field_type.index('[')]
if type(field_val) == str:
if not base_type in ['char', 'uint8']:
raise SerializationError(
'field %s must be a list or tuple type. Only uint8[] can be a string'
% field_name)
else:
#It's a string so its already in byte format and we
#don't need to check the individual bytes in the
#string.
return
if not type(field_val) in [list, tuple]:
raise SerializationError('field %s must be a list or tuple type' %
field_name)
for v in field_val:
check_type(field_name + "[]", base_type, v)
else:
if isinstance(field_val, Message):
# roslib/Header is the old location of Header. We check it for backwards compat
if field_val._type in ['std_msgs/Header', 'roslib/Header']:
if field_type not in [
'Header', 'std_msgs/Header', 'roslib/Header'
]:
raise SerializationError(
"field %s must be a Header instead of a %s" %
(field_name, field_val._type))
elif field_val._type != field_type:
raise SerializationError(
"field %s must be of type %s instead of %s" %
(field_name, field_type, field_val._type))
for n, t in zip(field_val.__slots__, field_val._get_types()):
check_type("%s.%s" % (field_name, n), t, getattr(field_val, n))
else:
raise SerializationError("field %s must be of type [%s]" %
(field_name, field_type))
def array_serializer_generator(msg_context, package, type_, name, serialize, is_numpy):
"""
Generator for array types
:raises: :exc:`MsgGenerationException` If array spec is invalid
"""
base_type, is_array, array_len = genmsg.msgs.parse_type(type_)
if not is_array:
raise MsgGenerationException("Invalid array spec: %s"%type_)
var_length = array_len is None
# handle fixed-size byte arrays could be slightly more efficient
# as we recalculated the length in the generated code.
if base_type in ['char', 'uint8']: #treat unsigned int8 arrays as string type
for y in string_serializer_generator(package, type_, name, serialize):
yield y
return
var = _serial_context+name
# yield length serialization, if necessary
if var_length:
for y in len_serializer_generator(var, False, serialize):
yield y #serialize array length
length = None
else:
length = array_len
#optimization for simple arrays
if is_simple(base_type):
if var_length:
pattern = compute_struct_pattern([base_type])
yield "pattern = '<%%s%s'%%length"%pattern
if serialize:
if is_numpy:
yield pack_numpy(var)
else:
yield pack2('pattern', "*"+var)
else:
yield "start = end"
yield "end += struct.calcsize(pattern)"
if is_numpy:
dtype = NUMPY_DTYPE[base_type]
yield unpack_numpy(var, 'length', dtype, 'str[start:end]')
else:
yield unpack2(var, 'pattern', 'str[start:end]')
else:
pattern = "%s%s"%(length, compute_struct_pattern([base_type]))
if serialize:
if is_numpy:
yield pack_numpy(var)
else:
yield pack(pattern, "*"+var)
else:
yield "start = end"
yield "end += %s"%struct.calcsize('<%s'%pattern)
if is_numpy:
dtype = NUMPY_DTYPE[base_type]
yield unpack_numpy(var, length, dtype, 'str[start:end]')
else:
yield unpack(var, pattern, 'str[start:end]')
if not serialize and base_type == 'bool':
# convert uint8 to bool
if base_type == 'bool':
yield "%s = map(bool, %s)"%(var, var)
else:
#generic recursive serializer
#NOTE: this is functionally equivalent to the is_registered branch of complex_serializer_generator
# choose a unique temporary variable for iterating
loop_var = 'val%s'%len(_context_stack)
# compute the variable context and factory to use
if base_type == 'string':
push_context('')
factory = string_serializer_generator(package, base_type, loop_var, serialize)
else:
push_context('%s.'%loop_var)
factory = serializer_generator(msg_context, get_registered_ex(msg_context, base_type), serialize, is_numpy)
if serialize:
yield 'for %s in %s:'%(loop_var, var)
else:
yield '%s = []'%var
if var_length:
yield 'for i in range(0, length):'
else:
yield 'for i in range(0, %s):'%length
if base_type != 'string':
yield INDENT + '%s = %s'%(loop_var, compute_constructor(msg_context, package, base_type))
for y in factory:
yield INDENT + y
if not serialize:
yield INDENT + '%s.append(%s)'%(var, loop_var)
pop_context()
def check_type(field_name, field_type, field_val):
"""
Dynamic type checker that maps ROS .msg types to python types and
verifies the python value. check_type() is not designed to be
fast and is targeted at error diagnosis. This type checker is not
designed to run fast and is meant only for error diagnosis.
:param field_name: ROS .msg field name, ``str``
:param field_type: ROS .msg field type, ``str``
:param field_val: field value, ``Any``
:raises: :exc:`SerializationError` If typecheck fails
"""
if is_simple(field_type):
# check sign and width
if field_type in ['byte', 'int8', 'int16', 'int32', 'int64']:
if type(field_val) not in [long, int]:
raise SerializationError('field %s must be an integer type'%field_name)
maxval = int(math.pow(2, _widths[field_type]-1))
if field_val >= maxval or field_val <= -maxval:
raise SerializationError('field %s exceeds specified width [%s]'%(field_name, field_type))
elif field_type in ['char', 'uint8', 'uint16', 'uint32', 'uint64']:
if type(field_val) not in [long, int] or field_val < 0:
raise SerializationError('field %s must be unsigned integer type'%field_name)
maxval = int(math.pow(2, _widths[field_type]))
if field_val >= maxval:
raise SerializationError('field %s exceeds specified width [%s]'%(field_name, field_type))
elif field_type == 'bool':
if field_val not in [True, False, 0, 1]:
raise SerializationError('field %s is not a bool'%(field_name))
elif field_type == 'string':
if sys.hexversion > 0x03000000:
if type(field_val) == str:
try:
field_val.encode('ascii')
except UnicodeEncodeError:
raise SerializationError('field %s is a non-ascii string'%field_name)
elif not type(field_val) == bytes:
raise SerializationError('field %s must be of type bytes or an ascii string'%field_name)
else:
if type(field_val) == unicode:
raise SerializationError('field %s is a unicode string instead of an ascii string'%field_name)
elif not isstring(field_val):
raise SerializationError('field %s must be of type str'%field_name)
elif field_type == 'time':
if not isinstance(field_val, Time):
raise SerializationError('field %s must be of type Time'%field_name)
elif field_type == 'duration':
if not isinstance(field_val, Duration):
raise SerializationError('field %s must be of type Duration'%field_name)
elif field_type.endswith(']'): # array type
# use index to generate error if '[' not present
base_type = field_type[:field_type.index('[')]
if type(field_val) == str:
if not base_type in ['char', 'uint8']:
raise SerializationError('field %s must be a list or tuple type. Only uint8[] can be a string' % field_name);
else:
#It's a string so its already in byte format and we
#don't need to check the individual bytes in the
#string.
return
if not type(field_val) in [list, tuple]:
raise SerializationError('field %s must be a list or tuple type'%field_name)
for v in field_val:
check_type(field_name+"[]", base_type, v)
else:
if isinstance(field_val, Message):
# roslib/Header is the old location of Header. We check it for backwards compat
if field_val._type in ['std_msgs/Header', 'roslib/Header']:
if field_type not in ['Header', 'std_msgs/Header', 'roslib/Header']:
raise SerializationError("field %s must be a Header instead of a %s"%(field_name, field_val._type))
elif field_val._type != field_type:
raise SerializationError("field %s must be of type %s instead of %s"%(field_name, field_type, field_val._type))
for n, t in zip(field_val.__slots__, field_val._get_types()):
check_type("%s.%s"%(field_name,n), t, getattr(field_val, n))
else:
raise SerializationError("field %s must be of type [%s]"%(field_name, field_type))
