Channels and Flows ‐ When to use each of them - devrath/KotlinAlchemy GitHub Wiki
Similar aspects of Flows and Channels
- Channels and Flows are both used for concurrency in kotlin co-routines.
- They both help to achieve
asynchronous behavior.
Features of Channels
1. Low level communication
Channels provide a low-level API compared to flows, If you need more fine-grained control over co-routines and emissions of data, the channels are a better fit.
2. Buffered communication
Channels can either be buffered or can not be buffered, This allows us to control the amount of data that is being sent even before receiving data in the receiver.
3. Selective Communication
Channels help in implementing complex communication patterns, Ex: Making the channel wait before multiple channels perform complex operations using the SELECT operation.
4. Closed Channel Handling
Channels have explicit support for the channel close operation(isClosedForReceive, isClosedForSend), allowing coroutines to react to the end of the communication.
Features of Flows
1. Higher level abstractions
Since they are built on top of the channels, They provide additional features that channels do that provide for streams of data like operators.
2. Transformations and Operators
Using operators we can compose and react to data streams in an efficient manner. Some operators include map,filter,collectLatest.
3. Cancellation Propagation
They provide mechanisms of cancellation. When a co-routine is canceled the cancellation can be propagated upstream and handled accordingly.
4. Built-in Backpressure Handling
When the downstream collector is slower than the upstream emitters, Flow provides mechanisms of backpressure handling by avoiding overflowing buffers.
Choosing Between Channels and Flows
- If you need low-level control, selectivity, or explicit handling of closed channels, channels might be a better fit.
- If you prefer a higher-level, declarative, and composable API with built-in support for cancellation and backpressure, flows are a good choice.