Control the Cloud C++ client library behavior with respect to polling on long running operations.
Some operations in Cloud services return a google.longrunning.Operation object. As their name implies, these objects represent requests that may take a long time to complete, in some cases operations may take tens of seconds or even 30 minutes to complete.
The Cloud C++ client libraries models these long running operations as a google::cloud::future<StatusOr<T>>, where T represents the final result of the operation. In the background, the library polls the service until the operation completes (or fails) and then satisfies the future.
This class defines the interface for policies that control the behavior of this polling loop.
See Also
https://aip.dev/151 for more information on long running operations.
Functions
clone() const
Return a copy of the current policy.
This function is called at the beginning of the polling loop. Policies that are based on relative time should restart their timers when this function is called.
| Returns | |
|---|---|
| Type | Description |
std::unique_ptr< PollingPolicy > | |
OnFailure(Status const &)
A callback to indicate that a polling attempt failed.
This is called when a polling request fails. Note that this callback is not invoked when the polling request succeeds with "operation not done".
| Parameter | |
|---|---|
| Name | Description |
status |
Status const &
|
| Returns | |
|---|---|
| Type | Description |
bool | true if the failure should be treated as transient and the polling loop should continue. |
WaitPeriod()
How long should the polling loop wait before trying again.
| Returns | |
|---|---|
| Type | Description |
std::chrono::milliseconds | |