Reactive support

[mp911de]

Add another layer between command creation and execution (today a command is created and immediately executed). Reactive commands should be only executed (example from RxJava as soon as call is invoked).

This layer could be located between the command builder and the async connection itself.

[mp911de]

4.x package: com.lambdaworks.redis.api.rx

New interfaces:

• BaseRedisReactiveCommands
• RedisHashReactiveCommands
• RedisHLLReactiveCommands
• RedisKeyReactiveCommands
• RedisListReactiveCommands
• RedisScriptingReactiveCommands
• RedisSentinelReactiveCommands
• RedisServerReactiveCommands
• RedisSetReactiveCommands
• RedisSortedSetReactiveCommands
• RedisStringReactiveCommands
• RedisTransactionalReactiveCommands

[mp911de]

Open issues:

Collection results

What about collection result types like lists and sets? Should these be dissolved into particular elements?

Iterables

Sync API:

// sync API
List<String> result = redis.hkeys("...");

Rx API:

// either
Observable<String> result = redis.hkeys("...");

// or
Observable<List<String>> result = redis.hkeys("...");

Maps

Sync API:

// sync API
Map<String, String> result = redis.hmget("...");

Rx API:

// either
Observable<KeyValue<String, String>> result = redis.hmget("...");

// or
Observable<Map<String, String>> result = redis.hmget("...");

PubSub

Provide hot observables for subscription listeners?

Cluster

Provide observable commands also for node-selection commands? (Commands executed on multiple cluster nodes)

[xasx]

What would be the advantage of emitting List<String> (Iterable!) over simply String?

Grouping could be done using groupBy operator.

[mp911de]

None.

Rx does not differentiate between one and many elements. Dissolving Iterables and other multi-element containers such as Map into singular values or tuples fit very well into the Rx pattern. This is, however, a change of result types in contrast to other API's within lettuce.

If you approach from pure Rx dissolved elements are welcome, but if you're used to Lists and Maps then you have to shift from collections to reactions on elements.

[mp911de]

Btw. nice to hear from you @xasx

[mp911de]

Javadocs available at http://redis.paluch.biz/docs/api/snapshots/latest/com/lambdaworks/redis/api/rx/RedisReactiveCommands.html

[mp911de]

Observables emit single elements and Maps