add parquet support

src/titiler/xarray/pyproject.toml

@@ -55,6 +55,7 @@ test = [
     "pytest-asyncio",
     "httpx",
     "kerchunk",
+    "fastparquet",
 ]
 
 [project.urls]

src/titiler/xarray/tests/test_io_tools.py

@@ -8,6 +8,7 @@
 import numpy
 import pytest
 import xarray
+from kerchunk.df import refs_to_dataframe
 from kerchunk.hdf import SingleHdf5ToZarr
 
 from titiler.xarray.io import Reader, get_variable
@@ -152,19 +153,33 @@ def test_kerchunk_reference(tmp_path):
     d.mkdir()
 
     netcdf = os.path.join(prefix, "dataset_3d.nc")
+
+    # JSON kerchunk
     reference = os.path.join(
         str(d),
         "reference.json",
     )
-
     with fsspec.open(netcdf, mode="rb", anon=True) as infile:
         h5chunks = SingleHdf5ToZarr(infile, netcdf, inline_threshold=100)
         with open(reference, "w") as f:
+            out_dict = h5chunks.translate()
             f.write(json.dumps(h5chunks.translate()))
 
-    for protocol in ["", "reference://"]:
-        src_path = protocol + reference
-        assert Reader.list_variables(src_path) == ["dataset"]
-        with Reader(src_path, variable="dataset") as src:
-            assert src.info()
-            assert src.tile(0, 0, 0)
+    src_path = "reference://" + reference
+    assert Reader.list_variables(src_path) == ["dataset"]
+    with Reader(src_path, variable="dataset") as src:
+        assert src.info()
+        assert src.tile(0, 0, 0)
+
+    # kerchunk Parquet impl
+    reference_parquet = os.path.join(
+        str(d),
+        "reference.parq",
+    )
+
+    refs_to_dataframe(out_dict, reference_parquet)
+    src_path = "reference://" + reference_parquet
+    assert Reader.list_variables(src_path) == ["dataset"]
+    with Reader(src_path, variable="dataset") as src:
+        assert src.info()
+        assert src.tile(0, 0, 0)

src/titiler/xarray/titiler/xarray/io.py

@@ -46,6 +46,7 @@ def xarray_engine(src_path: str) -> str:
     #  ".hdf", ".hdf5", ".h5" will be supported once we have tests + expand the type permitted for the group parameter
     if any(src_path.lower().endswith(ext) for ext in [".nc", ".nc4"]):
         return "h5netcdf"
+
     return "zarr"
 
 
@@ -67,14 +68,15 @@ def get_filesystem(
             if xr_engine == "h5netcdf"
             else s3fs.S3Map(root=src_path, s3=s3_filesystem)
         )
-    elif protocol == "reference" or src_path.lower().endswith(".json"):
+
+    elif protocol == "reference":
         reference_args = {
             "fo": src_path.replace("reference://", ""),
             "remote_options": {"anon": anon},
         }
         return fsspec.filesystem("reference", **reference_args).get_mapper("")
 
-    elif protocol in ["https", "http", "file", "reference"]:
+    elif protocol in ["https", "http", "file"]:
         if protocol.startswith("http"):
             assert (
                 aiohttp is not None
@@ -120,13 +122,7 @@ def xarray_open_dataset(
     if group is not None:
         xr_open_args["group"] = group
 
-    # NetCDF arguments
-    if xr_engine == "h5netcdf":
-        xr_open_args["engine"] = "h5netcdf"
-        xr_open_args["lock"] = False
-        ds = xarray.open_dataset(file_handler, **xr_open_args)
-
-    elif protocol == "reference" or src_path.lower().endswith(".json"):
+    if protocol == "reference":
         xr_open_args.update(
             {
                 "engine": "zarr",
@@ -137,8 +133,27 @@ def xarray_open_dataset(
 
         ds = xarray.open_dataset(file_handler, **xr_open_args)
 
+    # NetCDF arguments
+    elif xr_engine == "h5netcdf":
+        xr_open_args.update(
+            {
+                "engine": "h5netcdf",
+                "lock": False,
+            }
+        )
+
+        ds = xarray.open_dataset(file_handler, **xr_open_args)
+
     # Fallback to Zarr
     else:
+        if protocol == "reference":
+            xr_open_args.update(
+                {
+                    "consolidated": False,
+                    "backend_kwargs": {"consolidated": False},
+                }
+            )
+
         ds = xarray.open_zarr(file_handler, **xr_open_args)
 
     if cache_client: