Relabuf - smart buffer with release valve

• consumes items from external future
• buffers internally up to hard_cap
• when hard_cap is reached no longer consumes causing producer to backoff and slowdown
• capable of releasing contents ONLY under certain conditions
• a release_after has passed since the latest successful content release(or since start) and buffer is not empty
• a soft_cap of items were added
• each consumption should be either confirmed or returned to the buffer
• returns usually happen due to error(for example DB is down) - so it's possible to configure a backoff
• backoff essentially overrides time release valve
• exposes released items via a future user can await on

  Install

[dependencies] relabuf = "~0.12.0"