Defines the interface for access token generators.
Instances of this class can generate OAuth2 access tokens. These are used to authenticate with Google Cloud Platform (and other Google Services), and may be useful for applications that directly invoke REST-based services.
Performance
Creating a new access token is relatively expensive. It may require remote calls via HTTP, or at the very least some (local) cryptographic operations.
Most implementations of this class will cache an access token until it is about to expire. Application developers are advised to keep AccessTokenGenerator instances for as long as possible. They should also avoid caching the access token themselves, as caching is already provided by the implementation.
Thread Safety
It is safe to call an instance of this class from two separate threads.
Error Handling
This class uses StatusOr<T> to report errors. When an operation fails to perform its work the returned StatusOr<T> contains the error details. If the ok() member function in the StatusOr<T> returns true then it contains the expected result. Please consult the google::cloud::StatusOr documentation for more details.
Functions
GetToken()
Returns an OAuth2 access token.
This function caches the access token to avoid the cost of recomputing the token on each call.
| Returns | |
|---|---|
| Type | Description |
StatusOr< AccessToken > | |