Pre-compute sequence-dim coordinates in prepare_target

[rabernat]

We currently build up the sequence-dim coordinate (usually time) one chunk at a time. As noted by @shoyer in #86 (comment), it may often be possible to pre-populate this information and write the entire chunk at once inside prepare_target.

An alternative would be to consolidate the sequence_dim chunks at the end, in finalize_target. That would likely be more robust to corner cases.

[martindurant]

Is there a possibility of a post-process step to consolidate coordinate data? It could depend on some heuristic for chunk-size.

[rabernat]

That is what finalize_target is for.

https://github.com/pangeo-forge/pangeo-forge/blob/3314162568f7d8fe3d6f06627b936cee55d99c9c/pangeo_forge/recipe.py#L316-L324

We could easily add consolidation of chunks to that step.

[rabernat]

The post-write consolidation of coordinates has been implemented in #210. I'm going to close this for now. Thanks for the suggestions everyone.