Crate sabi_redis 

This crate provides several DataSrc and DataConn derived classes to enable data access to Redis within the Rust sabi framework.

RedisDataSrc and RedisDataConn are designed for a standalone Redis server and provide synchronous connections for processing Redis commands.

Redis does not support transactions like relational databases (RDBs) and lacks the ability to roll back updated data. Therefore, when used in conjunction with other databases, an inconsistency can occur if an error happens mid-process: the RDB’s updates might be rolled back, but the Redis updates remain. To address this, this crate offers three features to give developers an opportunity to revert updates: “force back”, “pre-commit” and “post-commit”.

Force Back

The DataConn derived class provided by this crate is equipped with the add_force_back method. You can use this method to store functions in the DataConn that will be executed during the rollback process within sabi::txn!.

This is useful for things like deleting newly added data or reverting data that is unlikely to have concurrent updates, such as session data. For data that might have concurrent updates, it would likely require measures like using WATCH, MULTI, and EXEC.

Pre-Commit

The DataConn derived class provided by this crate is equipped with the add_pre_commit method. You can use this method to store functions in the DataConn that will be executed right before the commit process within sabi::txn!.

By performing Redis updates after all other database updates, you can avoid the need for a rollback if an error occurs with the other databases. This is a good option if you can ensure that the updated data will not be re-fetched within the same transaction.

Post-Commit

The DataConn derived class provided by this crate is equipped with the add_post_commit method. You can use this method to store functions in the DataConn that will be executed after the commit process within sabi::txn!.

Since it’s executed after the commit of the updates to other databases is complete, there’s no need to consider rolling back Redis updates even if an error occurs with the other database updates. However, you must be aware that if an error occurs during the Redis update itself, the partial updates to Redis cannot be undone, and the other database updates will already be committed. It would be necessary to ensure that the impact on the system is not critical if such a situation occurs, and to enable error detection so that manual recovery can be performed later.

Structs

RedisDataConn

A session-scoped connection to the Redis server.

RedisDataSrc

Manages a connection pool for a Redis data source.

Enums

RedisDataSrcError

Represents a reason for errors that can occur during RedisDataSrc operations, to be passed to errs::Err.