don't throw error on emtpy area geometry

mapchete_eo/array/convert.py

@@ -2,6 +2,7 @@
 
 import numpy as np
 import numpy.ma as ma
+from numpy.typing import DTypeLike
 import xarray as xr
 from mapchete.types import NodataVal
 
@@ -19,7 +20,9 @@
 
 
 def to_masked_array(
-    xarr: Union[xr.Dataset, xr.DataArray], copy: bool = False
+    xarr: Union[xr.Dataset, xr.DataArray],
+    copy: bool = False,
+    out_dtype: Optional[DTypeLike] = None,
 ) -> ma.MaskedArray:
     """Convert xr.DataArray to ma.MaskedArray."""
     if isinstance(xarr, xr.Dataset):
@@ -31,6 +34,9 @@ def to_masked_array(
             "Cannot create masked_array because DataArray fill value is None"
         )
 
+    if out_dtype:
+        xarr = xarr.astype(out_dtype, copy=False)
+
     if xarr.dtype in _NUMPY_FLOAT_DTYPES:
         return ma.masked_values(xarr, fill_value, copy=copy, shrink=False)
     else:

mapchete_eo/base.py

@@ -6,6 +6,7 @@
 
 import croniter
 from mapchete import Bounds
+import numpy as np
 import numpy.ma as ma
 import xarray as xr
 from dateutil.tz import tzutc
@@ -18,6 +19,8 @@
 from mapchete.types import MPathLike, NodataVal, NodataVals
 from pydantic import BaseModel
 from rasterio.enums import Resampling
+from rasterio.features import geometry_mask
+from shapely.geometry import mapping
 from shapely.geometry.base import BaseGeometry
 
 from mapchete_eo.archives.base import Archive
@@ -62,6 +65,7 @@ class EODataCube(base.InputTile):
     eo_bands: dict
     time: List[TimeRange]
     area: BaseGeometry
+    area_pixelbuffer: int = 0
 
     def __init__(
         self,
@@ -367,6 +371,29 @@ def default_read_values(
             nodatavals=nodatavals,
             merge_products_by=merge_products_by,
             merge_method=merge_method,
+            read_mask=self.get_read_mask(),
+        )
+
+    def get_read_mask(self) -> np.ndarray:
+        """
+        Determine read mask according to input area.
+
+        This will generate a numpy array where pixel overlapping the input area
+        are set True and thus will get filled by the read function. Pixel outside
+        of the area are not considered for reading.
+
+        On staged reading, i.e. first checking the product masks to assess valid
+        pixels, this will avoid reading product bands in cases the product only covers
+        pixels outside of the intended reading area.
+        """
+        area = self.area.buffer(self.area_pixelbuffer * self.tile.pixel_x_size)
+        if area.is_empty:
+            return np.zeros((self.tile.shape), dtype=bool)
+        return geometry_mask(
+            geometries=[mapping(area)],
+            out_shape=self.tile.shape,
+            transform=self.tile.transform,
+            invert=True,
         )
 
 
@@ -443,8 +470,9 @@ def _init_area(self, input_params: dict) -> BaseGeometry:
                     input_params.get("delimiters", {}).get("bounds"),
                     crs=getattr(input_params.get("pyramid"), "crs"),
                 ),
+                raise_if_empty=False,
             )
-            return process_area.intersection(
+            process_area = process_area.intersection(
                 reproject_geometry(
                     configured_area,
                     src_crs=configured_area_crs or self.crs,

mapchete_eo/io/items.py

@@ -56,7 +56,7 @@ def item_to_np_array(
     return out
 
 
-def expand_params(param, length):
+def expand_params(param: Any, length: int) -> List[Any]:
     """
     Expand parameters if they are not a list.
     """
@@ -104,8 +104,10 @@ def get_item_property(
     | ``collection``     | The collection ID of an Item's collection.             |
     +--------------------+--------------------------------------------------------+
     """
-    if property in ["year", "month", "day", "date", "datetime"]:
-        if item.datetime is None:
+    if property == "id":
+        return item.id
+    elif property in ["year", "month", "day", "date", "datetime"]:
+        if item.datetime is None:  # pragma: no cover
             raise ValueError(
                 f"STAC item has no datetime attached, thus cannot get property {property}"
             )

mapchete_eo/io/levelled_cubes.py

@@ -40,27 +40,50 @@ def read_levelled_cube_to_np_array(
     raise_empty: bool = True,
     out_dtype: DTypeLike = np.uint16,
     out_fill_value: NodataVal = 0,
+    read_mask: Optional[np.ndarray] = None,
 ) -> ma.MaskedArray:
     """
     Read products as slices into a cube by filling up nodata gaps with next slice.
+
+    If a read_mask is provided, only the pixels marked True are considered to be read.
     """
-    if len(products) == 0:
+    if len(products) == 0:  # pragma: no cover
         raise NoSourceProducts("no products to read")
-
     bands = assets or eo_bands
-    if bands is None:
+    if bands is None:  # pragma: no cover
         raise ValueError("either assets or eo_bands have to be set")
-
     out_shape = (target_height, len(bands), *grid.shape)
+
+    # 2D read_mask shape
+    if read_mask is None:
+        read_mask = np.ones(grid.shape, dtype=bool)
+    elif read_mask.ndim != 2:  # pragma: no cover
+        raise ValueError(
+            "read_mask must be 2-dimensional, not %s-dimensional",
+            read_mask.ndim,
+        )
     out: ma.MaskedArray = ma.masked_array(
-        data=np.zeros(out_shape, dtype=out_dtype),
-        mask=np.ones(out_shape, dtype=out_dtype),
+        data=np.full(out_shape, out_fill_value, dtype=out_dtype),
+        mask=np.ones(out_shape, dtype=bool),
         fill_value=out_fill_value,
     )
+
+    if not read_mask.any():
+        logger.debug("nothing to read")
+        return out
+
+    # extrude mask to match each layer
+    layer_read_mask = np.stack([read_mask for _ in bands])
+
+    def _cube_read_mask() -> np.ndarray:
+        # This is only needed for debug output, thus there is no need to materialize always
+        return np.stack([layer_read_mask for _ in range(target_height)])
+
     logger.debug(
-        "empty cube with shape %s has %s",
+        "empty cube with shape %s has %s and %s pixels to be filled",
         out.shape,
         pretty_bytes(out.size * out.itemsize),
+        _cube_read_mask().sum(),
     )
 
     logger.debug("sort products into slices ...")
@@ -76,25 +99,25 @@ def read_levelled_cube_to_np_array(
     slices_read_count, slices_skip_count = 0, 0
 
     # pick slices one by one
-    for slice_count, slice in enumerate(slices, 1):
+    for slice_count, slice_ in enumerate(slices, 1):
         # all filled up? let's get outta here!
         if not out.mask.any():
-            logger.debug("cube is full, quitting!")
+            logger.debug("cube has no pixels to be filled, quitting!")
             break
 
         # generate 2D mask of holes to be filled in output cube
-        cube_nodata_mask = out.mask.any(axis=0).any(axis=0)
+        cube_nodata_mask = np.logical_and(out.mask.any(axis=0).any(axis=0), read_mask)
 
         # read slice
         try:
             logger.debug(
                 "see if slice %s %s has some of the %s unmasked pixels for cube",
                 slice_count,
-                slice,
+                slice_,
                 cube_nodata_mask.sum(),
             )
-            with slice.cached():
-                slice_array = slice.read(
+            with slice_.cached():
+                slice_array = slice_.read(
                     merge_method=merge_method,
                     product_read_kwargs=dict(
                         product_read_kwargs,
@@ -104,17 +127,18 @@ def read_levelled_cube_to_np_array(
                         resampling=resampling,
                         nodatavals=nodatavals,
                         raise_empty=raise_empty,
-                        target_mask=~cube_nodata_mask.copy(),
+                        read_mask=cube_nodata_mask.copy(),
+                        out_dtype=out_dtype,
                     ),
                 )
             slices_read_count += 1
         except (EmptySliceException, CorruptedSlice) as exc:
-            logger.debug("skipped slice %s: %s", slice, str(exc))
+            logger.debug("skipped slice %s: %s", slice_, str(exc))
             slices_skip_count += 1
             continue
 
         # if slice was not empty, fill pixels into cube
-        logger.debug("add slice %s array to cube", slice)
+        logger.debug("add slice %s array to cube", slice_)
 
         # iterate through layers of cube
         for layer_index in range(target_height):
@@ -124,34 +148,35 @@ def read_levelled_cube_to_np_array(
                 continue
 
             # determine empty patches of current layer
-            empty_patches = out[layer_index].mask.copy()
-            pixels_for_layer = (~slice_array[empty_patches].mask).sum()
+            empty_patches = np.logical_and(out[layer_index].mask, layer_read_mask)
+            remaining_pixels_for_layer = (~slice_array[empty_patches].mask).sum()
 
             # when slice has nothing to offer for this layer, skip
-            if pixels_for_layer == 0:
+            if remaining_pixels_for_layer == 0:
                 logger.debug(
                     "layer %s: slice has no pixels for this layer, jump to next",
                     layer_index,
                 )
                 continue
 
+            # insert slice data into empty patches of layer
             logger.debug(
                 "layer %s: fill with %s pixels ...",
                 layer_index,
-                pixels_for_layer,
+                remaining_pixels_for_layer,
             )
-            # insert slice data into empty patches of layer
             out[layer_index][empty_patches] = slice_array[empty_patches]
-            masked_pixels = out[layer_index].mask.sum()
-            total_pixels = out[layer_index].size
-            percent_full = round(
-                100 * ((total_pixels - masked_pixels) / total_pixels), 2
-            )
+
+            # report on layer fill status
             logger.debug(
-                "layer %s: %s%% filled (%s empty pixels remaining)",
+                "layer %s: %s",
                 layer_index,
-                percent_full,
-                out[layer_index].mask.sum(),
+                _percent_full(
+                    remaining=np.logical_and(
+                        out[layer_index].mask, layer_read_mask
+                    ).sum(),
+                    total=layer_read_mask.sum(),
+                ),
             )
 
             # remove slice values which were just inserted for next layer
@@ -161,13 +186,13 @@ def read_levelled_cube_to_np_array(
                 logger.debug("slice fully inserted into cube, skipping")
                 break
 
-        masked_pixels = out.mask.sum()
-        total_pixels = out.size
-        percent_full = round(100 * ((total_pixels - masked_pixels) / total_pixels), 2)
+        # report on layer fill status
         logger.debug(
-            "cube is %s%% filled (%s empty pixels remaining)",
-            percent_full,
-            masked_pixels,
+            "cube is %s",
+            _percent_full(
+                remaining=np.logical_and(out.mask, _cube_read_mask()).sum(),
+                total=_cube_read_mask().sum(),
+            ),
         )
 
     logger.debug(
@@ -197,6 +222,7 @@ def read_levelled_cube_to_xarray(
     band_axis_name: str = "bands",
     x_axis_name: str = "x",
     y_axis_name: str = "y",
+    read_mask: Optional[np.ndarray] = None,
 ) -> xr.Dataset:
     """
     Read products as slices into a cube by filling up nodata gaps with next slice.
@@ -218,6 +244,7 @@ def read_levelled_cube_to_xarray(
             sort=sort,
             product_read_kwargs=product_read_kwargs,
             raise_empty=raise_empty,
+            read_mask=read_mask,
         ),
         slice_names=[f"layer-{ii}" for ii in range(target_height)],
         band_names=variables,
@@ -226,3 +253,7 @@ def read_levelled_cube_to_xarray(
         x_axis_name=x_axis_name,
         y_axis_name=y_axis_name,
     )
+
+
+def _percent_full(remaining: int, total: int, ndigits: int = 2) -> str:
+    return f"{round(100 * (total - remaining) / total, ndigits=ndigits)}% full ({remaining} remaining emtpy pixels)"