Add support for slicing joinable data items

[andeaseme]

A common data format with stream2py is chunks of data like segments of waveforms that can be joined together.

The issue is with the BufferReader.range() returns a list of chunks often with extra to trim off at the start and stop since the query falls somewhere inside a chunk. For these cases, it would be good to have range join and trim to get a more exact query.

I would add optional abstract methods to SourceReader that are for joining and slicing read data items and have BufferReader.range() use that and return a single joined data item

┆Issue is synchronized with this Asana task by Unito

[thorwhalen]

See also:

creek design ideas

session_block_stores

keywords: session/block queries, timeseries queries, panel data