Remove Store.set_partial_writes

This feature was unused by the rest of Zarr-Python, and was only
implemented for LocalStore and stores that wrap other stores.

The Zarr v3 spec still mentions partial writes, so it should probably
also be updated.

Author: shoyer

changes/2859.removal.rst

@@ -0,0 +1,2 @@
+The ``Store.set_partial_writes`` method, which was not used by Zarr-Python, has been removed.
+``store.supports_partial_writes`` is now always ``False``.

src/zarr/abc/store.py

@@ -4,7 +4,7 @@
 from asyncio import gather
 from dataclasses import dataclass
 from itertools import starmap
-from typing import TYPE_CHECKING, Protocol, runtime_checkable
+from typing import TYPE_CHECKING, Literal, Protocol, runtime_checkable
 
 if TYPE_CHECKING:
     from collections.abc import AsyncGenerator, AsyncIterator, Iterable
@@ -310,25 +310,12 @@ async def delete(self, key: str) -> None:
         ...
 
     @property
-    @abstractmethod
-    def supports_partial_writes(self) -> bool:
-        """Does the store support partial writes?"""
-        ...
-
-    @abstractmethod
-    async def set_partial_values(
-        self, key_start_values: Iterable[tuple[str, int, BytesLike]]
-    ) -> None:
-        """Store values at a given key, starting at byte range_start.
+    def supports_partial_writes(self) -> Literal[False]:
+        """Does the store support partial writes?
 
-        Parameters
-        ----------
-        key_start_values : list[tuple[str, int, BytesLike]]
-            set of key, range_start, values triples, a key may occur multiple times with different
-            range_starts, range_starts (considering the length of the respective values) must not
-            specify overlapping ranges for the same key
+        Partial writes are no longer used by Zarr, so this is always false.
         """
-        ...
+        return False
 
     @property
     @abstractmethod
@@ -499,7 +486,7 @@ async def get(
         self, prototype: BufferPrototype, byte_range: ByteRequest | None = None
     ) -> Buffer | None: ...
 
-    async def set(self, value: Buffer, byte_range: ByteRequest | None = None) -> None: ...
+    async def set(self, value: Buffer) -> None: ...
 
     async def delete(self) -> None: ...
 

src/zarr/storage/_common.py

@@ -163,24 +163,15 @@ async def get(
             prototype = default_buffer_prototype()
         return await self.store.get(self.path, prototype=prototype, byte_range=byte_range)
 
-    async def set(self, value: Buffer, byte_range: ByteRequest | None = None) -> None:
+    async def set(self, value: Buffer) -> None:
         """
         Write bytes to the store.
 
         Parameters
         ----------
         value : Buffer
             The buffer to write.
-        byte_range : ByteRequest, optional
-            The range of bytes to write. If None, the entire buffer is written.
-
-        Raises
-        ------
-        NotImplementedError
-            If `byte_range` is not None, because Store.set does not support partial writes yet.
         """
-        if byte_range is not None:
-            raise NotImplementedError("Store.set does not have partial writes yet")
         await self.store.set(self.path, value)
 
     async def delete(self) -> None:

src/zarr/storage/_fsspec.py

@@ -418,12 +418,6 @@ async def get_partial_values(
 
         return [None if isinstance(r, Exception) else prototype.buffer.from_bytes(r) for r in res]
 
-    async def set_partial_values(
-        self, key_start_values: Iterable[tuple[str, int, BytesLike]]
-    ) -> None:
-        # docstring inherited
-        raise NotImplementedError
-
     async def list(self) -> AsyncIterator[str]:
         # docstring inherited
         allfiles = await self.fs._find(self.path, detail=False, withdirs=False)

src/zarr/storage/_local.py

@@ -77,23 +77,12 @@ def _atomic_write(
         raise
 
 
-def _put(
-    path: Path,
-    value: Buffer,
-    start: int | None = None,
-    exclusive: bool = False,
-) -> int | None:
+def _put(path: Path, value: Buffer, exclusive: bool = False) -> int:
     path.parent.mkdir(parents=True, exist_ok=True)
     # write takes any object supporting the buffer protocol
     view = value.as_buffer_like()
-    if start is not None:
-        with path.open("r+b") as f:
-            f.seek(start)
-            f.write(view)
-        return None
-    else:
-        with _atomic_write(path, "wb", exclusive=exclusive) as f:
-            return f.write(view)
+    with _atomic_write(path, "wb", exclusive=exclusive) as f:
+        return f.write(view)
 
 
 class LocalStore(Store):
@@ -111,14 +100,12 @@ class LocalStore(Store):
     ----------
     supports_writes
     supports_deletes
-    supports_partial_writes
     supports_listing
     root
     """
 
     supports_writes: bool = True
     supports_deletes: bool = True
-    supports_partial_writes: bool = True
     supports_listing: bool = True
 
     root: Path
@@ -253,19 +240,7 @@ async def _set(self, key: str, value: Buffer, exclusive: bool = False) -> None:
                 f"LocalStore.set(): `value` must be a Buffer instance. Got an instance of {type(value)} instead."
             )
         path = self.root / key
-        await asyncio.to_thread(_put, path, value, start=None, exclusive=exclusive)
-
-    async def set_partial_values(
-        self, key_start_values: Iterable[tuple[str, int, bytes | bytearray | memoryview]]
-    ) -> None:
-        # docstring inherited
-        self._check_writable()
-        args = []
-        for key, start, value in key_start_values:
-            assert isinstance(key, str)
-            path = self.root / key
-            args.append((_put, path, value, start))
-        await concurrent_map(args, asyncio.to_thread, limit=None)  # TODO: fix limit
+        await asyncio.to_thread(_put, path, value, exclusive=exclusive)
 
     async def delete(self, key: str) -> None:
         """

src/zarr/storage/_logging.py

@@ -115,11 +115,6 @@ def supports_deletes(self) -> bool:
         with self.log():
             return self._store.supports_deletes
 
-    @property
-    def supports_partial_writes(self) -> bool:
-        with self.log():
-            return self._store.supports_partial_writes
-
     @property
     def supports_listing(self) -> bool:
         with self.log():
@@ -207,14 +202,6 @@ async def delete(self, key: str) -> None:
         with self.log(key):
             return await self._store.delete(key=key)
 
-    async def set_partial_values(
-        self, key_start_values: Iterable[tuple[str, int, bytes | bytearray | memoryview]]
-    ) -> None:
-        # docstring inherited
-        keys = ",".join([k[0] for k in key_start_values])
-        with self.log(keys):
-            return await self._store.set_partial_values(key_start_values=key_start_values)
-
     async def list(self) -> AsyncGenerator[str, None]:
         # docstring inherited
         with self.log():

src/zarr/storage/_memory.py

@@ -32,13 +32,11 @@ class MemoryStore(Store):
     ----------
     supports_writes
     supports_deletes
-    supports_partial_writes
     supports_listing
     """
 
     supports_writes: bool = True
     supports_deletes: bool = True
-    supports_partial_writes: bool = True
     supports_listing: bool = True
 
     _store_dict: MutableMapping[str, Buffer]
@@ -143,12 +141,6 @@ async def delete(self, key: str) -> None:
         except KeyError:
             logger.debug("Key %s does not exist.", key)
 
-    async def set_partial_values(
-        self, key_start_values: Iterable[tuple[str, int, bytes | bytearray | memoryview[int]]]
-    ) -> None:
-        # docstring inherited
-        raise NotImplementedError
-
     async def list(self) -> AsyncIterator[str]:
         # docstring inherited
         for key in self._store_dict:

src/zarr/storage/_obstore.py

@@ -196,17 +196,6 @@ async def delete(self, key: str) -> None:
         with contextlib.suppress(FileNotFoundError):
             await obs.delete_async(self.store, key)
 
-    @property
-    def supports_partial_writes(self) -> bool:
-        # docstring inherited
-        return False
-
-    async def set_partial_values(
-        self, key_start_values: Iterable[tuple[str, int, BytesLike]]
-    ) -> None:
-        # docstring inherited
-        raise NotImplementedError
-
     @property
     def supports_listing(self) -> bool:
         # docstring inherited

src/zarr/storage/_wrapper.py

@@ -119,15 +119,6 @@ def supports_deletes(self) -> bool:
     async def delete(self, key: str) -> None:
         await self._store.delete(key)
 
-    @property
-    def supports_partial_writes(self) -> bool:
-        return self._store.supports_partial_writes
-
-    async def set_partial_values(
-        self, key_start_values: Iterable[tuple[str, int, BytesLike]]
-    ) -> None:
-        return await self._store.set_partial_values(key_start_values)
-
     @property
     def supports_listing(self) -> bool:
         return self._store.supports_listing

src/zarr/storage/_zip.py

@@ -48,7 +48,6 @@ class ZipStore(Store):
     allowed_exceptions
     supports_writes
     supports_deletes
-    supports_partial_writes
     supports_listing
     path
     compression
@@ -57,7 +56,6 @@ class ZipStore(Store):
 
     supports_writes: bool = True
     supports_deletes: bool = False
-    supports_partial_writes: bool = False
     supports_listing: bool = True
 
     path: Path
@@ -222,11 +220,6 @@ async def set(self, key: str, value: Buffer) -> None:
         with self._lock:
             self._set(key, value)
 
-    async def set_partial_values(
-        self, key_start_values: Iterable[tuple[str, int, bytes | bytearray | memoryview[int]]]
-    ) -> None:
-        raise NotImplementedError
-
     async def set_if_not_exists(self, key: str, value: Buffer) -> None:
         self._check_writable()
         with self._lock: