FHashes

Rationale

Most use cases for flowthings.io will involve time series data. However, there are circumstances in which time is irrelevant. In these circumstances, ensuring drop uniqueness may become relevant. FHashes are a means of enforcing drop uniqueness.

Use Cases

Uniqueness

FHashes are optional. They may be enabled for a drop by setting the toplevel attribute fhash for the drop.

Each unique drop has its own distinct fhash. Flows know which fhashes they have processed and will only process drops with fhashes not before seen.

Drop Reference

FHashes also provide the ability to reference specific drops using the Flow.js function

Flow.Drop.findFHash(flowId, fhash)

Required Parameters

  • flowId - string containing Flow's id or path
  • fhash - FHash of Drop to be found

Returns

Returns json representation of drop with specified fhash, if found. Else, returns null.

Throws

Throws an instance of Flow.Error.