RPC runtime for python #9 (#10)

* Implement RPC runtime for python #9

- Implement Service, WsgiApp to create nirum rpc service
  - Add nirum.rpc.WsgiApp, nirum.rpc.Service
  - Return appropriate error message / success response
  - Support /ping/ by default
- Fix deserializers
  - deserialize by class not from given data
  - deserialize generic type(eg. typing.Sequence) as python type
  - deserialize primitive type

* Fix deserialize_tuple_type, reviews

* Divide rpc requirements into service_requires

* Parse datetime by using iso8601

* All name can have behind name

* Reveal behind name in error message

nirum/deserialize.py

@@ -2,21 +2,144 @@
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 """
+import datetime
+import decimal
+import typing
+import uuid
+
+from iso8601 import iso8601, parse_date
+
 __all__ = (
-    'deserialize_boxed_type', 'deserialize_meta',
-    'deserialize_record_type', 'deserialize_union_type',
+    'deserialize_abstract_type',
+    'deserialize_boxed_type',
+    'deserialize_iterable_abstract_type',
+    'deserialize_meta',
+    'deserialize_primitive',
+    'deserialize_record_type',
+    'deserialize_tuple_type',
+    'deserialize_union_type',
+    'is_support_abstract_type',
 )
+_NIRUM_PRIMITIVE_TYPE = {
+    str, float, decimal.Decimal, uuid.UUID, datetime.datetime,
+    datetime.date, bool, int
+}
 
 
-def deserialize_meta(cls, data):
-    if not isinstance(data, dict):
+def is_support_abstract_type(t):
+    """FIXME: 3.5 only"""
+    if hasattr(t, '__origin__') and t.__origin__:
+        data_type = t.__origin__
+    else:
+        data_type = t
+    abstract_types = {
+        typing.Sequence,
+        typing.List,
+        typing.Set,
+        typing.Mapping,
+        typing.Dict,
+    }
+    return any(type_ is data_type for type_ in abstract_types)
+
+
+def deserialize_iterable_abstract_type(cls, cls_origin_type, data):
+    abstract_type_map = {
+        typing.Sequence: list,
+        typing.List: list,
+        typing.Set: set,
+    }
+    deserialized_data = data
+    cls_primitive_type = abstract_type_map[cls_origin_type]
+    if isinstance(cls.__parameters__[0], typing.TypeVar):
+        deserialized_data = cls_primitive_type(data)
+    else:
+        deserialized_data = cls_primitive_type(
+            deserialize_meta(cls.__parameters__[0], d) for d in data
+        )
+    return deserialized_data
+
+
+def deserialize_abstract_type(cls, data):
+    abstract_type_map = {
+        typing.Sequence: list,
+        typing.List: list,
+        typing.Mapping: dict,
+        typing.Dict: dict,
+        typing.Set: set,
+    }
+    cls_origin_type = cls.__origin__
+    if cls_origin_type is None:
+        cls_origin_type = cls
+    iterable_types = {typing.Sequence, typing.List, typing.Tuple, typing.Set}
+    if cls_origin_type in iterable_types:
+        return deserialize_iterable_abstract_type(cls, cls_origin_type, data)
+    else:
+        return abstract_type_map[cls_origin_type](data)
+
+
+def deserialize_tuple_type(cls, data):
+    if not cls.__tuple_params__:
+        return tuple(data)
+    if len(cls.__tuple_params__) != len(data):
+        raise ValueError(
+            'Expected {}-tuple, not {}-tuple'.format(
+                len(cls.__tuple_params__), len(data)
+            )
+        )
+    return tuple(
+        deserialize_meta(t, d)
+        for t, d in zip(cls.__tuple_params__, data)
+    )
+
+
+def deserialize_primitive(cls, data):
+    if cls is datetime.datetime:
+        try:
+            d = parse_date(data)
+        except iso8601.ParseError:
+            raise ValueError("'{}' is not a datetime.".format(data))
+    elif cls is datetime.date:
+        try:
+            d = parse_date(data).date()
+        except iso8601.ParseError:
+            raise ValueError("'{}' is not a date.".format(data))
+    elif cls in {int, float, uuid.UUID, bool}:
+        d = cls(data)
+    elif cls is decimal.Decimal:
+        try:
+            d = cls(data)
+        except decimal.InvalidOperation:
+            raise ValueError("'{}' is not a decimal.".format(data))
+    elif cls is str:
+        if not isinstance(data, str):
+            raise ValueError("'{}' is not a string.")
         d = cls(data)
-    elif '_type' in data and '_tag' in data:
+    else:
+        raise TypeError(
+            "'{0.__qualname__}' is not a primitive type.".format(cls)
+        )
+    return d
+
+
+def deserialize_meta(cls, data):
+    if hasattr(cls, '__nirum_tag__'):
         d = deserialize_union_type(cls, data)
-    elif '_type' in data:
+    elif hasattr(cls, '__nirum_record_behind_name__'):
         d = deserialize_record_type(cls, data)
+    elif hasattr(cls, '__nirum_boxed_type__'):
+        d = deserialize_boxed_type(cls, data)
+    elif type(cls) is typing.TupleMeta:
+        # typing.Tuple dosen't have either `__origin__` and `__parameters__`
+        # so it have to be handled special case.
+        d = deserialize_tuple_type(cls, data)
+    elif is_support_abstract_type(cls):
+        d = deserialize_abstract_type(cls, data)
+    elif callable(cls) and cls in _NIRUM_PRIMITIVE_TYPE:
+        d = deserialize_primitive(cls, data)
     else:
-        raise TypeError('data is not deserializable: {!r}'.format(data))
+        raise TypeError('data is not deserializable: {!r} as {!r}'.format(
+            data, cls
+        ))
     return d
 
 

nirum/exc.py

@@ -0,0 +1,36 @@
+""":mod:nirum.exc`
+~~~~~~~~~~~~~~~~~~
+
+"""
+__all__ = (
+    'InvalidNirumServiceMethodNameError',
+    'InvalidNirumServiceMethodTypeError',
+    'NirumProcedureArgumentError',
+    'NirumProcedureArgumentRequiredError',
+    'NirumProcedureArgumentValueError',
+    'NirumServiceError',
+)
+
+
+class NirumServiceError(Exception):
+    """Base nirum service error"""
+
+
+class InvalidNirumServiceMethodNameError(ValueError, NirumServiceError):
+    """Raised when nirum service has invalid method name."""
+
+
+class InvalidNirumServiceMethodTypeError(TypeError, NirumServiceError):
+    """Raised when nirum service method is not callable."""
+
+
+class NirumProcedureArgumentError(ValueError, NirumServiceError):
+    """WIP"""
+
+
+class NirumProcedureArgumentRequiredError(NirumProcedureArgumentError):
+    """WIP"""
+
+
+class NirumProcedureArgumentValueError(NirumProcedureArgumentError):
+    """WIP"""