Views

A View is a combination of one or more Blocks. For instance:

from dask_geomodeling.raster import RasterFileSource, Group
source_1 = RasterFileSource("path/to/some/tiff")
source_2 = RasterFileSource("path/to/another/tiff")
view = Group(source_1, source_1)

View serialization

A View consists of several Block instances that reference each other. To serialize this we use Dask’s graph format. This graph format replaces the nested structure by a flat dictionary with internal references

Warning

A serialized view looks much alike a compute graph. Don’t get confused!

An example using the above view definition:

serialized_view = view.serialize()

{
  "version": 2,
  "graph": {
    "RasterFileSource_300b56b278d49bea13eff68f8cf52f90": [
      "dask_geomodeling.raster.sources.RasterFileSource",
      "file:///path/to/some/tiff"
    ],
    "RasterFileSource_9dc43c9bd98e2f9069e2b0c879d76cb1": [
      "dask_geomodeling.raster.sources.RasterFileSource",
      "file:///path/to/another/tiff"
    ],
    "Group_0d0a99fe65bffe87dd045627c27bcbbb": [
      "dask_geomodeling.raster.combine.Group",
      "RasterFileSource_300b56b278d49bea13eff68f8cf52f90",
      "RasterFileSource_9dc43c9bd98e2f9069e2b0c879d76cb1"
    ]
  },
  "name": "Group_0d0a99fe65bffe87dd045627c27bcbbb"
}

The above “view graph” contains all three operations that we defined together with their arguments. The names are automatically generated and contain a hash which is useful to uniquely determine the block. Also, we see the “name”, that points to the endpoint block.

To deserialize the view:

from dask_geomodeling.core import Block
view = Block.deserialize(serialized_view)

The methods Block.to_json and Block.from_json, or Block.get_graph and dask_geomodeling.construct serve the same purpose, but they in/output different object types.