fixups

Author: TomAugspurger

docs/guide/storage.rst

@@ -97,5 +97,13 @@ Zarr-Python :class:`zarr.abc.store.Store` API is meant to be extended. The Store
 Class includes all of the methods needed to be a fully operational store in Zarr Python.
 Zarr also provides a test harness for custom stores: :class:`zarr.testing.store.StoreTests`.
 
+``Store.get``
+~~~~~~~~~~~~~
+
+The ``prototype`` keyword of :func:`zarr.abc.store.Store.get` uses a default of
+``None``.  When given ``None``, implementations should use
+:func:`zarr.buffer.default_buffer_prototype` to look up the prototype users have
+configured.
+
 .. _Zip Store Specification: https://github.com/zarr-developers/zarr-specs/pull/311
 .. _Fsspec: https://zarr-specs.readthedocs.io/en/latest/v3/core/v3.0.html#consolidated-metadata

src/zarr/abc/store.py

@@ -199,7 +199,7 @@ def __eq__(self, value: object) -> bool:
     async def get(
         self,
         key: str,
-        prototype: BufferPrototype,
+        prototype: BufferPrototype | None = None,
         byte_range: ByteRangeRequest | None = None,
     ) -> Buffer | None:
         """Retrieve the value associated with a given key.
@@ -208,6 +208,9 @@ async def get(
         ----------
         key : str
         byte_range : tuple[int | None, int | None], optional
+        prototype: BufferPrototype, optional
+            The prototype giving the buffer classes to use for buffers and nbuffers.
+            By default, :func:`zarr.buffer.default_buffer_prototype` is used.
 
         Returns
         -------

src/zarr/buffer.py

@@ -0,0 +1,5 @@
+from zarr.core.buffer import default_buffer_prototype
+
+__all__ = [
+    "default_buffer_prototype",
+]

src/zarr/storage/local.py

@@ -9,6 +9,7 @@
 
 from zarr.abc.store import ByteRangeRequest, Store
 from zarr.core.buffer import Buffer
+from zarr.core.buffer.core import default_buffer_prototype
 from zarr.core.common import concurrent_map
 
 if TYPE_CHECKING:
@@ -143,10 +144,12 @@ def __eq__(self, other: object) -> bool:
     async def get(
         self,
         key: str,
-        prototype: BufferPrototype,
+        prototype: BufferPrototype | None = None,
         byte_range: tuple[int | None, int | None] | None = None,
     ) -> Buffer | None:
         # docstring inherited
+        if prototype is None:
+            prototype = default_buffer_prototype()
         if not self._is_open:
             await self._open()
         assert isinstance(key, str)

src/zarr/storage/logging.py

@@ -159,7 +159,7 @@ def __eq__(self, other: object) -> bool:
     async def get(
         self,
         key: str,
-        prototype: BufferPrototype,
+        prototype: BufferPrototype | None = None,
         byte_range: tuple[int | None, int | None] | None = None,
     ) -> Buffer | None:
         # docstring inherited

src/zarr/storage/memory.py

@@ -4,6 +4,7 @@
 
 from zarr.abc.store import ByteRangeRequest, Store
 from zarr.core.buffer import Buffer, gpu
+from zarr.core.buffer.core import default_buffer_prototype
 from zarr.core.common import concurrent_map
 from zarr.storage._utils import _normalize_interval_index
 
@@ -79,10 +80,12 @@ def __eq__(self, other: object) -> bool:
     async def get(
         self,
         key: str,
-        prototype: BufferPrototype,
+        prototype: BufferPrototype | None = None,
         byte_range: tuple[int | None, int | None] | None = None,
     ) -> Buffer | None:
         # docstring inherited
+        if prototype is None:
+            prototype = default_buffer_prototype()
         if not self._is_open:
             await self._open()
         assert isinstance(key, str)

src/zarr/storage/remote.py

@@ -1,10 +1,11 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Any, Self, cast
+from typing import TYPE_CHECKING, Any, Self
 
 import fsspec
 
 from zarr.abc.store import ByteRangeRequest, Store
+from zarr.core.buffer.core import default_buffer_prototype
 from zarr.storage.common import _dereference_path
 
 if TYPE_CHECKING:
@@ -175,10 +176,12 @@ def __eq__(self, other: object) -> bool:
     async def get(
         self,
         key: str,
-        prototype: BufferPrototype,
+        prototype: BufferPrototype | None = None,
         byte_range: ByteRangeRequest | None = None,
     ) -> Buffer | None:
         # docstring inherited
+        if prototype is None:
+            prototype = default_buffer_prototype()
         if not self._is_open:
             await self._open()
         path = _dereference_path(self.path, key)
@@ -312,5 +315,5 @@ async def getsize(self, key: str) -> int:
             # Not all filesystems support size. Fall back to reading the entire object
             return await super().getsize(key)
         else:
-            # fsspec doesn't have typing. We'll need to assume this is correct.
-            return cast(int, size)
+            # fsspec doesn't have typing. We'll need to assume or verify this is true
+            return int(size)

src/zarr/storage/zip.py

@@ -9,6 +9,7 @@
 
 from zarr.abc.store import ByteRangeRequest, Store
 from zarr.core.buffer import Buffer, BufferPrototype
+from zarr.core.buffer.core import default_buffer_prototype
 
 if TYPE_CHECKING:
     from collections.abc import AsyncGenerator, Iterable
@@ -166,11 +167,13 @@ def _get(
     async def get(
         self,
         key: str,
-        prototype: BufferPrototype,
+        prototype: BufferPrototype | None = None,
         byte_range: ByteRangeRequest | None = None,
     ) -> Buffer | None:
         # docstring inherited
         assert isinstance(key, str)
+        if prototype is None:
+            prototype = default_buffer_prototype()
 
         with self._lock:
             return self._get(key, prototype=prototype, byte_range=byte_range)

src/zarr/testing/store.py

@@ -121,6 +121,15 @@ async def test_get(
         expected = data_buf[start : start + length]
         assert_bytes_equal(observed, expected)
 
+    async def test_get_default_prototype(self, store: S) -> None:
+        key = "c/0"
+        data = b"\x01\x02\x03\x04"
+        data_buf = self.buffer_cls.from_bytes(data)
+        await self.set(store, key, data_buf)
+        observed = await store.get(key)
+        expected = data_buf[:]
+        assert_bytes_equal(observed, expected)
+
     async def test_get_many(self, store: S) -> None:
         """
         Ensure that multiple keys can be retrieved at once with the _get_many method.

tests/test_codecs/test_blosc.py

@@ -5,8 +5,8 @@
 
 from zarr import AsyncArray
 from zarr.abc.store import Store
+from zarr.buffer import default_buffer_prototype
 from zarr.codecs import BloscCodec, BytesCodec, ShardingCodec
-from zarr.core.buffer import default_buffer_prototype
 from zarr.storage.common import StorePath