def process(self,
s,
file_path='<string>',
start_signature=MESSAGE_START_SIGNATURE,
info_only=False,
ignore_value_expectation=False,
wire_template_data=True):
"""
Decoding the given message string.
:param s: Message string that contains the BUFR Message
:param file_path: The file where this string is read from.
:param start_signature: Locate the starting position of the message
string with the given signature.
:param info_only: Only show information up to template data (exclusive)
:param ignore_value_expectation: Do not validate the expected value
:param wire_template_data: Whether to wire the template data to construct
a fully hierarchical structure from the flat lists. Only takes effect
when it is NOT info_only.
:return: A BufrMessage object that contains the decoded information.
"""
idx = s.find(start_signature) if start_signature is not None else 0
if idx == -1:
raise PyBufrKitError(
'Cannot find start signature: {}'.format(start_signature))
s = s[idx:]
bit_reader = get_bit_reader(s)
bufr_message = BufrMessage(file_path)
configuration_transformers = (
self.section_configurer.info_configuration, ) if info_only else ()
if ignore_value_expectation:
configuration_transformers += (
self.section_configurer.ignore_value_expectation, )
nbits_decoded = 0
section_index = 0 # Always start decoding from section 0
while True:
section = self.section_configurer.configure_section(
bufr_message, section_index, configuration_transformers)
section_index += 1
if section is None: # when optional section is not present
continue
nbits_decoded += self.process_section(bufr_message, bit_reader,
section)
if section.end_of_message:
break
# The exact bytes that have been decoded
bufr_message.serialized_bytes = s[:nbits_decoded // NBITS_PER_BYTE]
if not info_only and wire_template_data:
bufr_message.wire()
return bufr_message
def process(self, s, file_path='<string>', wire_template_data=True):
"""
Entry point for the encoding process. The process encodes a JSON format
message to BUFR message.
:param s: A JSON or its string serialized form
:param file_path: The file path to the JSON file.
:param wire_template_data: Whether to wire the template data to construct
a fully hierarchical structure from the flat lists.
:return: A bitstring object of the encoded message.
"""
if isinstance(s, (six.binary_type, six.text_type)):
# TODO: ensure all strings are loaded as plain ascii instead of unicode from JSON
json_data = json.loads(s) if six.PY3 else json.loads(s, encoding='latin-1')
else:
json_data = s
bit_writer = get_bit_writer()
bufr_message = BufrMessage(filename=file_path)
nbits_encoded = 0
section_index = 0
# When a section is not present in the json data. The index must not be
# increase for the section.
index_offset = 0
while True:
section = self.section_configurer.configure_section_with_values(
bufr_message, section_index, json_data[section_index - index_offset],
self.overrides)
section_index += 1
if section is None: # optional section is not present
index_offset += 1 # This section should not be counted
continue
nbits_encoded += self.process_section(bufr_message, bit_writer, section)
if section.end_of_message:
break
# A zero length means the actual length must be calculated
# Fix is needed for both the message object and the serialized bits
nbytes_write = bit_writer.get_pos() // NBITS_PER_BYTE
if bufr_message.length.value == 0 or self.ignore_declared_length:
bufr_message.length.value = nbytes_write
section = bufr_message.length.parent
bit_writer.set_uint(
bufr_message.length.value,
bufr_message.length.nbits,
section.get_metadata(BITPOS_START) + section.get_parameter_offset('length')
)
elif bufr_message.length.value != nbytes_write:
raise PyBufrKitError('Write exceeds declared total length {} by {} bytes'.format(
bufr_message.length.value, nbytes_write - bufr_message.length.value
))
bufr_message.serialized_bytes = bit_writer.to_bytes()
if wire_template_data:
bufr_message.wire()
return bufr_message