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S ) a* Contains metaclasses used to create protocol service and service stub
classes from ServiceDescriptor objects at runtime.
The GeneratedServiceType and GeneratedServiceStubType metaclasses are used to
inject all useful functionality into the classes output by the protocol
compiler at compile-time.
z petar@google.com (Petar Petrov)c @ s e Zd ZdZdZdd ZdS )GeneratedServiceTypea Metaclass for service classes created at runtime from ServiceDescriptors.
Implementations for all methods described in the Service class are added here
by this class. We also create properties to allow getting/setting all fields
in the protocol message.
The protocol compiler currently uses this metaclass to create protocol service
classes at runtime. Clients can also manually create their own classes at
runtime, as in this example:
mydescriptor = ServiceDescriptor(.....)
class MyProtoService(service.Service):
__metaclass__ = GeneratedServiceType
DESCRIPTOR = mydescriptor
myservice_instance = MyProtoService()
...
DESCRIPTORc C s. t j|krdS |t j }t|}|j| dS )a Creates a message service class.
Args:
name: Name of the class (ignored, but required by the metaclass
protocol).
bases: Base classes of the class being constructed.
dictionary: The class dictionary of the class being constructed.
dictionary[_DESCRIPTOR_KEY] must contain a ServiceDescriptor object
describing this protocol service type.
N)r _DESCRIPTOR_KEY_ServiceBuilder BuildService)clsnamebases
dictionary
descriptorZservice_builder r (/usr/lib/python3.6/service_reflection.py__init__@ s
z GeneratedServiceType.__init__N)__name__
__module__ __qualname____doc__r r
r r r r r * s r c s$ e Zd ZdZdZ fddZ ZS )GeneratedServiceStubTypezMetaclass for service stubs created at runtime from ServiceDescriptors.
This class has similar responsibilities as GeneratedServiceType, except that
it creates the service stub classes.
r c sB t t| j||| tj|kr"dS |tj }t|}|j| dS )a` Creates a message service stub class.
Args:
name: Name of the class (ignored, here).
bases: Base classes of the class being constructed.
dictionary: The class dictionary of the class being constructed.
dictionary[_DESCRIPTOR_KEY] must contain a ServiceDescriptor object
describing this protocol service type.
N)superr r
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Zservice_stub_builder) __class__r r r
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__classcell__r r )r r r T s r c @ sH e Zd ZdZdd Zdd Zdd Zdd Zd
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dS )r aD This class constructs a protocol service class using a service descriptor.
Given a service descriptor, this class constructs a class that represents
the specified service descriptor. One service builder instance constructs
exactly one service class. That means all instances of that class share the
same builder.
c C s
|| _ dS )zInitializes an instance of the service class builder.
Args:
service_descriptor: ServiceDescriptor to use when constructing the
service class.
N)r
)selfservice_descriptorr r r r
| s z_ServiceBuilder.__init__c sl fdd}| _ ||_t fdd|_d|j_ j|_ j|_x$ j j
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| qLW dS )z\Constructs the service class.
Args:
cls: The class that will be constructed.
c s j | ||||S )N) _CallMethod)srvcmethod_descriptorrpc_controllerrequestcallback)r r r _WrapCallMethod s z5_ServiceBuilder.BuildService.._WrapCallMethodc s j S )N)r
r )r r r s z._ServiceBuilder.BuildService..z Returns the service descriptor.N)r
CallMethod staticmethodZ
GetDescriptorr _GetRequestClassZGetRequestClass_GetResponseClassZGetResponseClassr
methodssetattrr _GenerateNonImplementedMethod)r r r methodr )r r r s
z _ServiceBuilder.BuildServicec C s, |j | jkrtdt||j}||||S )a Calls the method described by a given method descriptor.
Args:
srvc: Instance of the service for which this method is called.
method_descriptor: Descriptor that represent the method to call.
rpc_controller: RPC controller to use for this method's execution.
request: Request protocol message.
callback: A callback to invoke after the method has completed.
z.r )r r) r )r) r r r( s
z-_ServiceBuilder._GenerateNonImplementedMethodc C s |j d| |d dS )a
The body of all methods in the generated service class.
Args:
method_name: Name of the method being executed.
rpc_controller: RPC controller used to execute this method.
callback: A callback which will be invoked when the method finishes.
zMethod %s not implemented.N)Z SetFailed)r Z method_namer r r r r r/ s z%_ServiceBuilder._NonImplementedMethodN) r r r r r
r r r$ r% r( r/ r r r r r r s
r c @ s0 e Zd ZdZdd Zdd Zdd Zdd Zd
S ) r a Constructs a protocol service stub class using a service descriptor.
Given a service descriptor, this class constructs a suitable stub class.
A stub is just a type-safe wrapper around an RpcChannel which emulates a
local implementation of the service.
One service stub builder instance constructs exactly one class. It means all
instances of that class share the same service stub builder.
c C s
|| _ dS )zInitializes an instance of the service stub class builder.
Args:
service_descriptor: ServiceDescriptor to use when constructing the
stub class.
N)r
)r r r r r r
s z _ServiceStubBuilder.__init__c C s> dd }|| _ ||_x$| jjD ]}t||j| j| q W dS )zYConstructs the stub class.
Args:
cls: The class that will be constructed.
c S s
|| _ d S )N) rpc_channel)stubr1 r r r _ServiceStubInit s z>_ServiceStubBuilder.BuildServiceStub.._ServiceStubInitN)r r
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r& r' r _GenerateStubMethod)r r r3 r) r r r r s
z$_ServiceStubBuilder.BuildServiceStubc s d fdd S )Nc s j | |||S )N) _StubMethod)r0 r r r )r) r r r r!
s z9_ServiceStubBuilder._GenerateStubMethod..)Nr )r r) r )r) r r r4 s z'_ServiceStubBuilder._GenerateStubMethodc C s |j j||||jj|S )a The body of all service methods in the generated stub class.
Args:
stub: Stub instance.
method_descriptor: Descriptor of the invoked method.
rpc_controller: Rpc controller to execute the method.
request: Request protocol message.
callback: A callback to execute when the method finishes.
Returns:
Response message (in case of blocking call).
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