use standalone metadata object

pyproject.toml

@@ -27,7 +27,7 @@ authors = [
 [tool.poetry.dependencies]
 python = ">=3.9,<3.13"
 click = "^8.1.7"
-earthkit-data = "^0.5.6"
+earthkit-data = ">=0.5.6,<1"
 eccodes = "^1.5.0"
 numpy = "^1.26.4"
 polytope-client = "^0.7.4"

src/meteodatalab/grib_decoder.py

@@ -135,9 +135,9 @@ def load(self, field: GribField) -> None:
         self.values[key] = field.to_numpy(dtype=np.float32)
 
         if not self.metadata:
-            md = field.metadata()
+            md = field.metadata().override()
             self.metadata = {
-                "message": md,
+                "metadata": md,
                 **metadata.extract(md),
             }
 
@@ -360,7 +360,7 @@ def load(
             if extract_pv not in requests:
                 msg = f"{extract_pv=} was not a key of the given requests."
                 raise RuntimeError(msg)
-            return result | metadata.extract_pv(result[extract_pv].message)
+            return result | metadata.extract_pv(result[extract_pv].metadata)
         return result
 
     def load_fieldnames(
@@ -394,11 +394,11 @@ def save(
         If the field does not have a message attribute.
 
     """
-    if not hasattr(field, "message"):
-        msg = "The message attribute is required to write to the GRIB format."
+    if not hasattr(field, "metadata"):
+        msg = "The metadata attribute is required to write to the GRIB format."
         raise ValueError(msg)
 
-    md = field.message
+    md = field.metadata
 
     idx = {
         dim: field.coords[key]

src/meteodatalab/metadata.py

@@ -2,11 +2,9 @@
 
 # Standard library
 import dataclasses as dc
-import io
 import typing
 
 # Third-party
-import earthkit.data as ekd  # type: ignore
 import numpy as np
 import xarray as xr
 from earthkit.data.core.metadata import Metadata
@@ -21,7 +19,7 @@
 }
 
 
-def extract(metadata):
+def extract(metadata: Metadata):
     if metadata.get("gridType") == "unstructured_grid":
         vref_flag = False
     else:
@@ -41,37 +39,37 @@ def extract(metadata):
     }
 
 
-def override(message: Metadata, **kwargs: typing.Any) -> dict[str, typing.Any]:
-    """Override GRIB metadata contained in message.
+def override(metadata: Metadata, **kwargs: typing.Any) -> dict[str, typing.Any]:
+    """Override GRIB metadata.
 
     Note that no special consideration is made for maintaining consistency when
     overriding template definition keys such as productDefinitionTemplateNumber.
     Note that the origin components in x and y are left untouched.
 
     Parameters
     ----------
-    message : bytes
-        Byte string of the input GRIB message
+    metadata : Metadata
+        Metadata of the input GRIB metadata
     kwargs : Any
         Keyword arguments forwarded to earthkit-data GribMetadata override method
 
     Returns
     -------
     dict[str, Any]
-        Updated message byte string along with the geography and parameter namespaces
+        Updated metadata along with the geography and parameter namespaces
 
     """
 
-    if message["editionNumber"] == 1:
+    if metadata["editionNumber"] == 1:
         return {
-            "message": message,
-            **extract(message),
+            "metadata": metadata,
+            **extract(metadata),
         }
 
-    md = message.override(**kwargs)
+    md = metadata.override(**kwargs)
 
     return {
-        "message": md,
+        "metadata": md,
         **extract(md),
     }
 
@@ -98,7 +96,7 @@ def load_grid_reference(metadata) -> Grid:
 
     Parameters
     ----------
-    metadata : bytes
+    metadata : Metadata
         GRIB metadata defining the reference grid.
 
     Returns
@@ -162,29 +160,26 @@ def set_origin_xy(ds: dict[str, xr.DataArray], ref_param: str) -> None:
     if ref_param not in ds:
         raise KeyError(f"ref_param {ref_param} not present in dataset.")
 
-    ref_grid = load_grid_reference(ds[ref_param].message)
+    ref_grid = load_grid_reference(ds[ref_param].metadata)
     for field in ds.values():
         field.attrs |= compute_origin(ref_grid, field)
 
 
-def extract_pv(message: bytes) -> dict[str, xr.DataArray]:
+def extract_pv(metadata: Metadata) -> dict[str, xr.DataArray]:
     """Extract hybrid level coefficients.
 
     Parameters
     ----------
-    message : bytes
-        GRIB message containing the pv metadata.
+    message : Metadata
+        GRIB metadata containing the pv metadata.
 
     Returns
     -------
     dict[str, xarray.DataArray]
         Hybrid level coefficients.
 
     """
-    stream = io.BytesIO(message)
-    [grib_field] = ekd.from_source("stream", stream)
-
-    pv = grib_field.metadata("pv")
+    pv = metadata.get("pv")
 
     if pv is None:
         return {}
@@ -196,12 +191,12 @@ def extract_pv(message: bytes) -> dict[str, xr.DataArray]:
     }
 
 
-def extract_hcoords(metadata) -> dict[str, xr.DataArray]:
+def extract_hcoords(metadata: Metadata) -> dict[str, xr.DataArray]:
     """Extract horizontal coordinates.
 
     Parameters
     ----------
-    metadata : bytes
+    metadata : Metadata
         GRIB metadata containing the grid definition.
 
     Returns
@@ -217,43 +212,3 @@ def extract_hcoords(metadata) -> dict[str, xr.DataArray]:
             dims=("y", "x"), data=geo.longitudes().reshape(geo.shape())
         ),
     }
-
-
-def extract_keys(message: bytes, keys: typing.Any, single: bool = True) -> typing.Any:
-    """Extract keys from the GRIB message.
-
-    Parameters
-    ----------
-    message : bytes
-        The GRIB message.
-    keys : Any
-        Keys for which to extract values from the message.
-    single : bool, optional
-        Whether a single GRIB message should be expected.
-
-    Raises
-    ------
-    ValueError
-        if keys is None because the resulting metadata would point
-        to an eccodes handle that no longer exists resulting in a
-        possible segmentation fault
-
-    Returns
-    -------
-    Any
-        Single value if keys is a single value, tuple of values if
-        keys is a tuple, list of values if keys is a list. The type of
-        the value depends on the default type for the given key in eccodes.
-        If single is false, the above is returned within a list.
-
-    """
-    if keys is None:
-        raise ValueError("keys must be specified.")
-    stream = io.BytesIO(message)
-    source = ekd.from_source("stream", stream)
-
-    if single:
-        [grib_field] = source
-        return grib_field.metadata(keys)
-
-    return [grib_field.metadata(keys) for grib_field in source]

src/meteodatalab/operators/brn.py

@@ -70,5 +70,5 @@ def fbrn(
 
     return xr.DataArray(
         data=brn,
-        attrs=metadata.override(p.message, shortName="BRN"),
+        attrs=metadata.override(p.metadata, shortName="BRN"),
     )

src/meteodatalab/operators/crop.py

@@ -68,7 +68,7 @@ def crop(field: xr.DataArray, bounds: Bounds) -> xr.DataArray:
     return xr.DataArray(
         field.isel(x=slice(xmin, xmax + 1), y=slice(ymin, ymax + 1)),
         attrs=metadata.override(
-            field.message,
+            field.metadata,
             longitudeOfFirstGridPoint=lon_min,
             longitudeOfLastGridPoint=lon_max,
             Ni=ni,

src/meteodatalab/operators/destagger.py

@@ -81,7 +81,7 @@ def _update_grid(field: xr.DataArray, dim: Literal["x", "y"]) -> dict[str, Any]:
         lon_max = np.round(geo["longitudeOfLastGridPointInDegrees"] * 1e6)
         dx = np.round(geo["iDirectionIncrementInDegrees"] * 1e6)
         return metadata.override(
-            field.message,
+            field.metadata,
             longitudeOfFirstGridPoint=lon_min - dx / 2,
             longitudeOfLastGridPoint=lon_max - dx / 2,
         )
@@ -90,7 +90,7 @@ def _update_grid(field: xr.DataArray, dim: Literal["x", "y"]) -> dict[str, Any]:
         lat_max = np.round(geo["latitudeOfLastGridPointInDegrees"] * 1e6)
         dy = np.round(geo["jDirectionIncrementInDegrees"] * 1e6)
         return metadata.override(
-            field.message,
+            field.metadata,
             latitudeOfFirstGridPoint=lat_min - dy / 2,
             latitudeOfLastGridPoint=lat_max - dy / 2,
         )
@@ -100,7 +100,7 @@ def _update_vertical(field) -> dict[str, Any]:
     if field.vcoord_type != "model_level":
         raise ValueError("typeOfLevel must equal generalVertical")
     return metadata.override(
-        field.message,
+        field.metadata,
         typeOfLevel="generalVerticalLayer",
     )
 
@@ -151,7 +151,7 @@ def destagger(
             )
             .transpose(*dims)
             .assign_attrs({f"origin_{dim}": 0.0}, **attrs)
-            .assign_coords(metadata.extract_hcoords(attrs["message"]))
+            .assign_coords(metadata.extract_hcoords(attrs["metadata"]))
         )
     elif dim == "z":
         if field.origin_z != -0.5:

src/meteodatalab/operators/gis.py

@@ -228,13 +228,13 @@ def vref_rot2geolatlon(
         xr.DataArray(
             u_g,
             attrs=metadata.override(
-                u.message, resolutionAndComponentFlags=resolution_components_flags
+                u.metadata, resolutionAndComponentFlags=resolution_components_flags
             ),
         ),
         xr.DataArray(
             v_g,
             attrs=metadata.override(
-                v.message, resolutionAndComponentFlags=resolution_components_flags
+                v.metadata, resolutionAndComponentFlags=resolution_components_flags
             ),
         ),
     )

src/meteodatalab/operators/hzerocl.py

@@ -75,5 +75,5 @@ def fhzerocl(
 
     return xr.DataArray(
         data=hzerocl.where(hzerocl > 0),
-        attrs=metadata.override(t.message, shortName="HZEROCL"),
+        attrs=metadata.override(t.metadata, shortName="HZEROCL"),
     )

src/meteodatalab/operators/omega_slope.py

@@ -72,7 +72,7 @@ def omega_slope(
         data=res,
         attrs=metadata.override(
             # Eta-coordinate vertical velocity
-            etadot.message,
+            etadot.metadata,
             discipline=0,
             parameterCategory=2,
             parameterNumber=32,

src/meteodatalab/operators/pot_vortic.py

@@ -79,6 +79,6 @@ def compute_pot_vortic(
         dt_dlam * curl1 + dt_dphi * (curl2 + cor2) - dt_dzeta * (curl3 + cor3)
     ) / rho_tot
 
-    out.attrs = metadata.override(theta.message, shortName="POT_VORTIC")
+    out.attrs = metadata.override(theta.metadata, shortName="POT_VORTIC")
 
     return out

src/meteodatalab/operators/radiation.py

@@ -26,7 +26,7 @@ def compute_athd_s(athb_s: xr.DataArray, tsurf: xr.DataArray) -> xr.DataArray:
     """
     return xr.DataArray(
         data=athb_s / pc.emissivity_surface + pc.boltzman_cst * tsurf**4,
-        attrs=metadata.override(athb_s.message, shortName="ATHD_S"),
+        attrs=metadata.override(athb_s.metadata, shortName="ATHD_S"),
     )
 
 
@@ -48,5 +48,5 @@ def compute_swdown(diffuse: xr.DataArray, direct: xr.DataArray) -> xr.DataArray:
     """
     return xr.DataArray(
         data=(diffuse + direct).clip(min=0),
-        attrs=metadata.override(diffuse.message, shortName="ASOD_S"),
+        attrs=metadata.override(diffuse.metadata, shortName="ASOD_S"),
     )

src/meteodatalab/operators/regrid.py

@@ -306,7 +306,7 @@ def reproject_layer(field):
 
     attrs = field.attrs
     if md := _get_metadata(dst):
-        attrs = attrs | metadata.override(field.message, **md)
+        attrs = attrs | metadata.override(field.metadata, **md)
 
     return xr.DataArray(data, attrs=attrs)
 

src/meteodatalab/operators/relhum.py

@@ -56,6 +56,6 @@ def relhum(
     return xr.DataArray(
         data=result,
         attrs=metadata.override(
-            t.message, shortName=phase_conditions[phase]["shortName"]
+            t.metadata, shortName=phase_conditions[phase]["shortName"]
         ),
     )

src/meteodatalab/operators/rho.py

@@ -49,5 +49,5 @@ def compute_rho_tot(
 
     return xr.DataArray(
         data=p / (pc.r_d * t * (1.0 + pc.rvd_o * qv - q)),
-        attrs=metadata.override(p.message, shortName="DEN"),
+        attrs=metadata.override(p.metadata, shortName="DEN"),
     )

src/meteodatalab/operators/support_operators.py

@@ -72,7 +72,7 @@ def init_field_with_vcoord(
     #       in the interface
     # attrs
     attrs = parent.attrs | metadata.override(
-        parent.message, typeOfLevel=vcoord.type_of_level
+        parent.metadata, typeOfLevel=vcoord.type_of_level
     )
     # dims
     sizes = dict(parent.sizes.items()) | {"z": vcoord.size}

src/meteodatalab/operators/theta.py

@@ -29,5 +29,5 @@ def compute_theta(p: xr.DataArray, t: xr.DataArray) -> xr.DataArray:
 
     return xr.DataArray(
         data=(p0 / p) ** pc.rdocp * t,
-        attrs=metadata.override(p.message, shortName="PT"),
+        attrs=metadata.override(p.metadata, shortName="PT"),
     )

src/meteodatalab/operators/thetav.py

@@ -31,5 +31,5 @@ def fthetav(p: xr.DataArray, t: xr.DataArray, qv: xr.DataArray) -> xr.DataArray:
 
     return xr.DataArray(
         data=(p0 / p) ** pc.rdocp * t * (1.0 + (pc.rvd_o * qv / (1.0 - qv))),
-        attrs=metadata.override(t.message, shortName="THETA_V"),
+        attrs=metadata.override(t.metadata, shortName="THETA_V"),
     )