grpc.framework.interfaces.base package¶
Submodules¶
grpc.framework.interfaces.base.base module¶
The base interface of RPC Framework.
Implementations of this interface support the conduct of “operations”: exchanges between two distinct ends of an arbitrary number of data payloads and metadata such as a name for the operation, initial and terminal metadata in each direction, and flow control. These operations may be used for transfers of data, remote procedure calls, status indication, or anything else applications choose.
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class
grpc.framework.interfaces.base.base.
Completion
[source]¶ Bases:
object
An aggregate of the values exchanged upon operation completion.
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terminal_metadata
¶ A terminal metadata value for the operaton.
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code
¶ A code value for the operation.
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message
¶ A message value for the operation.
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class
grpc.framework.interfaces.base.base.
End
[source]¶ Bases:
object
Common type for entry-point objects on both sides of an operation.
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add_idle_action
(action)[source]¶ Adds an action to be called when this End has no ongoing operations.
Parameters: action – A callable that accepts no arguments.
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operate
(group, method, subscription, timeout, initial_metadata=None, payload=None, completion=None, protocol_options=None)[source]¶ Commences an operation.
Parameters: - group – The group identifier of the invoked operation.
- method – The method identifier of the invoked operation.
- subscription – A Subscription to which the results of the operation will be passed.
- timeout – A length of time in seconds to allow for the operation.
- initial_metadata – An initial metadata value to be sent to the other side of the operation. May be None if the initial metadata will be later passed via the returned operator or if there will be no initial metadata passed at all.
- payload – An initial payload for the operation.
- completion – A Completion value indicating the end of transmission to the other side of the operation.
- protocol_options – A value specified by the provider of a Base interface implementation affording custom state and behavior.
Returns: - A pair of objects affording information about the operation and action
continuing the operation. The first element of the returned pair is an OperationContext for the operation and the second element of the returned pair is an Operator to which operation values not passed in this call should later be passed.
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operation_stats
()[source]¶ Reports the number of terminated operations broken down by outcome.
Returns: - A dictionary from Outcome.Kind value to an integer identifying the number
- of operations that terminated with that outcome kind.
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stop
(grace)[source]¶ Stops this object’s service of operations.
This object will refuse service of new operations as soon as this method is called but operations under way at the time of the call may be given a grace period during which they are allowed to finish.
Parameters: grace – A duration of time in seconds to allow ongoing operations to terminate before being forcefully terminated by the stopping of this End. May be zero to terminate all ongoing operations and immediately stop. Returns: - A threading.Event that will be set to indicate all operations having
- terminated and this End having completely stopped. The returned event may not be set until after the full grace period (if some ongoing operation continues for the full length of the period) or it may be set much sooner (if for example this End had no operations in progress at the time its stop method was called).
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exception
grpc.framework.interfaces.base.base.
NoSuchMethodError
(code, details)[source]¶ Bases:
Exception
Indicates that an unrecognized operation has been called.
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code
¶ A code value to communicate to the other side of the operation along with indication of operation termination. May be None.
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details
¶ A details value to communicate to the other side of the operation along with indication of operation termination. May be None.
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class
grpc.framework.interfaces.base.base.
OperationContext
[source]¶ Bases:
object
Provides operation-related information and action.
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add_termination_callback
(callback)[source]¶ Adds a function to be called upon operation termination.
Parameters: callback – A callable to be passed an Outcome value on operation termination. Returns: - None if the operation has not yet terminated and the passed callback will
- later be called when it does terminate, or if the operation has already terminated an Outcome value describing the operation termination and the passed callback will not be called as a result of this method call.
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fail
(exception)[source]¶ Indicates that the operation has failed.
Parameters: exception – An exception germane to the operation failure. May be None.
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outcome
()[source]¶ Indicates the operation’s outcome (or that the operation is ongoing).
Returns: - None if the operation is still active or the Outcome value for the
- operation if it has terminated.
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time_remaining
()[source]¶ Describes the length of allowed time remaining for the operation.
Returns: A nonnegative float indicating the length of allowed time in seconds remaining for the operation to complete before it is considered to have timed out. Zero is returned if the operation has terminated.
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class
grpc.framework.interfaces.base.base.
Operator
[source]¶ Bases:
object
An interface through which to participate in an operation.
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advance
(initial_metadata=None, payload=None, completion=None, allowance=None)[source]¶ Progresses the operation.
Parameters: - initial_metadata – An initial metadata value. Only one may ever be communicated in each direction for an operation, and they must be communicated no later than either the first payload or the completion.
- payload – A payload value.
- completion – A Completion value. May only ever be non-None once in either direction, and no payloads may be passed after it has been communicated.
- allowance – A positive integer communicating the number of additional payloads allowed to be passed by the remote side of the operation.
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class
grpc.framework.interfaces.base.base.
Outcome
[source]¶ Bases:
object
The outcome of an operation.
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kind
¶ A Kind value coarsely identifying how the operation terminated.
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code
¶ An application-specific code value or None if no such value was provided.
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details
¶ An application-specific details value or None if no such value was provided.
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class
Kind
[source]¶ Bases:
enum.Enum
Ways in which an operation can terminate.
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CANCELLED
= <Kind.CANCELLED: 'cancelled'>¶
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COMPLETED
= <Kind.COMPLETED: 'completed'>¶
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EXPIRED
= <Kind.EXPIRED: 'expired'>¶
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LOCAL_FAILURE
= <Kind.LOCAL_FAILURE: 'local failure'>¶
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LOCAL_SHUTDOWN
= <Kind.LOCAL_SHUTDOWN: 'local shutdown'>¶
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RECEPTION_FAILURE
= <Kind.RECEPTION_FAILURE: 'reception failure'>¶
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REMOTE_FAILURE
= <Kind.REMOTE_FAILURE: 'remote failure'>¶
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REMOTE_SHUTDOWN
= <Kind.REMOTE_SHUTDOWN: 'remote shutdown'>¶
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TRANSMISSION_FAILURE
= <Kind.TRANSMISSION_FAILURE: 'transmission failure'>¶
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class
grpc.framework.interfaces.base.base.
ProtocolReceiver
[source]¶ Bases:
object
A means of receiving protocol values during an operation.
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class
grpc.framework.interfaces.base.base.
Servicer
[source]¶ Bases:
object
Interface for service implementations.
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service
(group, method, context, output_operator)[source]¶ Services an operation.
Parameters: - group – The group identifier of the operation to be serviced.
- method – The method identifier of the operation to be serviced.
- context – An OperationContext object affording contextual information and actions.
- output_operator – An Operator that will accept output values of the operation.
Returns: - A Subscription via which this object may or may not accept more values of
the operation.
Raises: NoSuchMethodError
– If this Servicer does not handle operations with the given group and method.abandonment.Abandoned
– If the operation has been aborted and there no longer is any reason to service the operation.
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class
grpc.framework.interfaces.base.base.
Subscription
[source]¶ Bases:
object
Describes customer code’s interest in values from the other side.
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kind
¶ A Kind value describing the overall kind of this value.
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termination_callback
¶ A callable to be passed the Outcome associated with the operation after it has terminated. Must be non-None if kind is Kind.TERMINATION_ONLY. Must be None otherwise.
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allowance
¶ A callable behavior that accepts positive integers representing the number of additional payloads allowed to be passed to the other side of the operation. Must be None if kind is Kind.FULL. Must not be None otherwise.
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operator
¶ An Operator to be passed values from the other side of the operation. Must be non-None if kind is Kind.FULL. Must be None otherwise.
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protocol_receiver
¶ A ProtocolReceiver to be passed protocol objects as they become available during the operation. Must be non-None if kind is Kind.FULL.
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grpc.framework.interfaces.base.utilities module¶
Utilities for use with the base interface of RPC Framework.
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grpc.framework.interfaces.base.utilities.
completion
(terminal_metadata, code, message)[source]¶ Creates a base.Completion aggregating the given operation values.
Parameters: - terminal_metadata – A terminal metadata value for an operaton.
- code – A code value for an operation.
- message – A message value for an operation.
Returns: A base.Completion aggregating the given operation values.
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grpc.framework.interfaces.base.utilities.
full_subscription
(operator, protocol_receiver)[source]¶ Creates a “full” base.Subscription for the given base.Operator.
Parameters: - operator – A base.Operator to be used in an operation.
- protocol_receiver – A base.ProtocolReceiver to be used in an operation.
Returns: - A base.Subscription of kind base.Subscription.Kind.FULL wrapping the given
base.Operator and base.ProtocolReceiver.