def _nonnull_coder_from_type(field_type):
type_info = field_type.WhichOneof("type_info")
if type_info == "atomic_type":
if field_type.atomic_type in (schema_pb2.INT32, schema_pb2.INT64):
return VarIntCoder()
elif field_type.atomic_type == schema_pb2.DOUBLE:
return FloatCoder()
elif field_type.atomic_type == schema_pb2.STRING:
return StrUtf8Coder()
elif field_type.atomic_type == schema_pb2.BOOLEAN:
return BooleanCoder()
elif field_type.atomic_type == schema_pb2.BYTES:
return BytesCoder()
elif type_info == "array_type":
return IterableCoder(_coder_from_type(field_type.array_type.element_type))
elif type_info == "map_type":
return MapCoder(
_coder_from_type(field_type.map_type.key_type),
_coder_from_type(field_type.map_type.value_type))
elif type_info == "row_type":
return RowCoder(field_type.row_type.schema)
# The Java SDK supports several more types, but the coders are not yet
# standard, and are not implemented in Python.
raise ValueError(
"Encountered a type that is not currently supported by RowCoder: %s" %
field_type)
def _nonnull_coder_from_type(field_type):
type_info = field_type.WhichOneof("type_info")
if type_info == "atomic_type":
if field_type.atomic_type in (schema_pb2.INT32, schema_pb2.INT64):
return VarIntCoder()
elif field_type.atomic_type == schema_pb2.DOUBLE:
return FloatCoder()
elif field_type.atomic_type == schema_pb2.STRING:
return StrUtf8Coder()
elif field_type.atomic_type == schema_pb2.BOOLEAN:
return BooleanCoder()
elif field_type.atomic_type == schema_pb2.BYTES:
return BytesCoder()
elif type_info == "array_type":
return IterableCoder(
_coder_from_type(field_type.array_type.element_type))
elif type_info == "map_type":
return MapCoder(_coder_from_type(field_type.map_type.key_type),
_coder_from_type(field_type.map_type.value_type))
elif type_info == "logical_type":
# Special case for the Any logical type. Just use the default coder for an
# unknown Python object.
if field_type.logical_type.urn == PYTHON_ANY_URN:
return typecoders.registry.get_coder(object)
logical_type = LogicalType.from_runner_api(field_type.logical_type)
return LogicalTypeCoder(
logical_type,
_coder_from_type(field_type.logical_type.representation))
elif type_info == "row_type":
return RowCoder(field_type.row_type.schema)
# The Java SDK supports several more types, but the coders are not yet
# standard, and are not implemented in Python.
raise ValueError(
"Encountered a type that is not currently supported by RowCoder: %s" %
field_type)
class RowCoderImpl(StreamCoderImpl):
"""For internal use only; no backwards-compatibility guarantees."""
SIZE_CODER = VarIntCoder().get_impl()
NULL_MARKER_CODER = BytesCoder().get_impl()
def __init__(self, schema, components):
self.schema = schema
self.constructor = named_tuple_from_schema(schema)
self.components = list(c.get_impl() for c in components)
self.has_nullable_fields = any(
field.type.nullable for field in self.schema.fields)
def encode_to_stream(self, value, out, nested):
nvals = len(self.schema.fields)
self.SIZE_CODER.encode_to_stream(nvals, out, True)
attrs = [getattr(value, f.name) for f in self.schema.fields]
words = array('B')
if self.has_nullable_fields:
nulls = list(attr is None for attr in attrs)
if any(nulls):
words = array('B', itertools.repeat(0, (nvals + 7) // 8))
for i, is_null in enumerate(nulls):
words[i // 8] |= is_null << (i % 8)
self.NULL_MARKER_CODER.encode_to_stream(words.tostring(), out, True)
for c, field, attr in zip(self.components, self.schema.fields, attrs):
if attr is None:
if not field.type.nullable:
raise ValueError(
"Attempted to encode null for non-nullable field \"{}\".".format(
field.name))
continue
c.encode_to_stream(attr, out, True)
def decode_from_stream(self, in_stream, nested):
nvals = self.SIZE_CODER.decode_from_stream(in_stream, True)
words = array('B')
words.fromstring(self.NULL_MARKER_CODER.decode_from_stream(in_stream, True))
if words:
nulls = ((words[i // 8] >> (i % 8)) & 0x01 for i in range(nvals))
else:
nulls = itertools.repeat(False, nvals)
# If this coder's schema has more attributes than the encoded value, then
# the schema must have changed. Populate the unencoded fields with nulls.
if len(self.components) > nvals:
nulls = itertools.chain(
nulls, itertools.repeat(True, len(self.components) - nvals))
# Note that if this coder's schema has *fewer* attributes than the encoded
# value, we just need to ignore the additional values, which will occur
# here because we only decode as many values as we have coders for.
return self.constructor(
*(
None if is_null else c.decode_from_stream(in_stream, True) for c,
is_null in zip(self.components, nulls)))
def _make_value_coder(self, nulls=itertools.repeat(False)):
components = [
component for component,
is_null in zip(self.components, nulls) if not is_null
] if self.has_nullable_fields else self.components
return TupleCoder(components).get_impl()
