Fix excessive memory usage in cf due to deep copies

xoa/cf.py

@@ -144,7 +144,6 @@ class SGLocator(object):
     _compile_sg_match_(re_match, valid_attrs, formats, root_patterns, location_pattern)
 
     def __init__(self, name_format=None, valid_locations=None, encoding=None):
-
         # Init
         self.formats = self.formats.copy()
         self.re_match = self.re_match.copy()
@@ -592,14 +591,12 @@ def patch_attrs(self, attrs, patch, loc=None, standardize=True, replace=False):
 
         # Loop patching on attributes
         for attr, value in patch.items():
-
             # Skip
             if value is None or (attr in attrs and not replace):
                 continue
 
             # Attr with loc
             if attr in self.valid_attrs:
-
                 # List
                 if isinstance(value, list):
                     if attr in attrs:
@@ -672,7 +669,7 @@ def format_dataarray(
         patch_attrs
         """
         if copy:
-            da = da.copy()
+            da = da.copy(deep=False)
 
         # Location argument
         loc = self.parse_loc_arg(loc)  # specified
@@ -781,7 +778,6 @@ class CFSpecs(object):
     """
 
     def __init__(self, cfg=None, default=True, user=True, name=None, cache=None):
-
         # Initialiase categories
         self._cfs = {}
         catcls = {"data_vars": CFVarSpecs, "coords": CFCoordSpecs}
@@ -823,7 +819,6 @@ def _load_cfg_as_dict_(self, cfg, cache=None):
             or (isinstance(cfg, dict) and "register" in cfg and cfg["register"]["name"])
         )
         if cache:
-
             # Init cache
             if isinstance(cfg, str):
                 cache_key = cfg
@@ -979,7 +974,6 @@ def set_specs(self, category, name, **specs):
         self.load_cfg(data)
 
     def _post_process_(self):
-
         # Inits
         items = {}
         for category in self.categories:
@@ -1051,7 +1045,6 @@ def _process_entry_(self, category, name):
 
         # Inherits from other specs (merge specs with dict_merge)
         if "inherit" in specs and specs["inherit"]:
-
             # From what?
             from_name = specs["inherit"]
             if ":" in from_name:
@@ -1263,7 +1256,7 @@ def _format_obj_(
         """
         # Copy
         if copy:
-            obj = obj.copy()
+            obj = obj.copy(deep=False)
 
         # Init rename dict
         rename_args = {}
@@ -2180,7 +2173,7 @@ def infer_coords(self, ds):
             for da in ds.data_vars.values():
                 if self.coords.match(da):
                     ds = ds.set_coords(da.name)
-        return ds.copy()
+        return ds.copy(deep=False)
 
 
 class _CFCatSpecs_(object):
@@ -2373,7 +2366,6 @@ def match(self, da, cf_name=None, loc=None):
         else:
             names = self.names
         for name_ in names:
-
             # Get match specs
             if isinstance(name_, dict):
                 match_specs = name_
@@ -2576,7 +2568,6 @@ def get_attrs(
         # Loop
         attrs = {}
         for key in specs["attrs"].keys():
-
             # No lists or tuples
             value = specs["attrs"][key]
             if isinstance(value, list):
@@ -2715,15 +2706,15 @@ def format_dataarray(
         if rename:
             copy = True
         if copy:
-            da = da.copy()
+            da = da.copy(deep=False)
 
         # Names
         if cf_name is None:
             cf_name = self.match(da)
         if cf_name is None:
             if not rename:
                 return
-            return da.copy() if copy else None
+            return da.copy(deep=False) if copy else None
         assert cf_name in self.names
         old_name = da.name
         new_name = self.get_name(cf_name, specialize=specialize)  # if specialize else cf_name
@@ -2734,7 +2725,6 @@ def format_dataarray(
 
         # Attributes
         if attrs is True:
-
             # Get attributes from Cf specs
             attrs = self.get_attrs(cf_name, loc=None, standardize=False, multi=True)
 
@@ -2914,7 +2904,6 @@ def get_dim_type(self, dim, obj=None, lower=True):
 
         # Check if a coordinate have the same name and an axis type
         if obj is not None:
-
             # Check dim validity
             if dim_loc not in obj.dims:
                 raise XoaCFError(f"dimension '{dim}' does not belong to obj")
@@ -3018,7 +3007,6 @@ def search_dim(self, obj, cf_arg=None, loc=None, single=True, errors="ignore"):
         # Loop on dims
         found = []
         for dim in obj.dims:
-
             # Filter-out by loc
             pname, ploc = self.sglocator.parse_attr('name', dim)
             ploc = self.sglocator.parse_loc_arg(ploc)
@@ -3117,7 +3105,6 @@ def get_ndim(o):
             return len(o.dims)
 
         if dim_type is not None:
-
             # Look for a coordinate with this dim_type
             #  starting from coordinates with a higher number of dimensions
             #  like depth that have more dims than level
@@ -3246,7 +3233,6 @@ def get_rename_dims_args(self, obj, locations=None, specialize=False):
         # Loop on dims
         rename_args = {}
         for dim in obj.dims:
-
             # Skip effective coordinate dims
             if dim in obj.coords:
                 continue
@@ -3585,7 +3571,6 @@ def get_default_cf_specs(cache="rw"):
 
     # Compute it from scratch
     if cfspecs is None:
-
         # Setup
         cfspecs = CFSpecs()
 
@@ -3641,7 +3626,6 @@ def get_cf_specs(name=None, cache="rw"):
     if name is None:
         name = "current"
     if not isinstance(name, str) or name not in ("current", "default"):
-
         # Registered name
         if isinstance(name, str):
             return get_cf_specs_from_name(name, errors="raise")