# Google Cloud Client Libraries for Rust - Long Running Operations API
**WARNING:** some RPCs have no corresponding Rust function to call them.
Typically these are streaming RPCs. We expect adding these RPCs in a
way that does not break the existing APIs or changes their behavior in a
significant way. We do anticipate a number of new crate dependencies
will be required. If you need these RPCs please open an issue in our
GitHub repository.
Defines types and an abstract service to handle long-running operations.
[Long-running operations] are a common pattern to handle methods that may take
a significant amount of time to execute. Many Google APIs return an `Operation`
message (defined in this package) that are roughly analogous to a future. The
operation will eventually complete, though it may still return an error on
completion. The client libraries provide helpers to simplify polling of these
operations.
[Long-running operations]: https://google.aip.dev/151
The client library types and functions are stable and not expected to change.
Please note that Google Cloud services do change from time to time. The client
libraries are designed to preserve backwards compatibility when the service
changes in compatible ways. For example, adding RPCs, or fields to messages
should not introduce breaking changes to the client libraries.
## Quickstart
The main types to work with this crate are the clients:
- [Operations]
## Features
- `default-rustls-provider`: enabled by default. Use the default rustls crypto
provider ([aws-lc-rs]) for TLS and authentication. Applications with specific
requirements for cryptography (such as exclusively using the [ring] crate)
should disable this default and call
`rustls::crypto::CryptoProvider::install_default()`.
## More Information
- Read the [crate's documentation](https://docs.rs/google-cloud-longrunning/1.11.0)
[aws-lc-rs]: https://crates.io/crates/aws-lc-rs
[ring]: https://crates.io/crates/ring
[Operations]: https://docs.rs/google-cloud-longrunning/1.11.0/google_cloud_longrunning/client/struct.Operations.html