Add methods for getting bytes + json to store abc (#3638)

* add store routines for getting bytes and json

* check for FileNotFoundError when a key is missing

* remove storepath methods

* changelog

* rename methods

* continue renaming / test refactoring

* refactor new test functions

* make new methods private

* remove changelog entry for private API

Author: d-v-b

src/zarr/abc/store.py

@@ -1,11 +1,14 @@
 from __future__ import annotations
 
+import asyncio
+import json
 from abc import ABC, abstractmethod
-from asyncio import gather
 from dataclasses import dataclass
 from itertools import starmap
 from typing import TYPE_CHECKING, Literal, Protocol, runtime_checkable
 
+from zarr.core.sync import sync
+
 if TYPE_CHECKING:
     from collections.abc import AsyncGenerator, AsyncIterator, Iterable
     from types import TracebackType
@@ -206,6 +209,211 @@ async def get(
         """
         ...
 
+    async def _get_bytes(
+        self, key: str, *, prototype: BufferPrototype, byte_range: ByteRequest | None = None
+    ) -> bytes:
+        """
+        Retrieve raw bytes from the store asynchronously.
+
+        This is a convenience method that wraps ``get()`` and converts the result
+        to bytes. Use this when you need the raw byte content of a stored value.
+
+        Parameters
+        ----------
+        key : str
+            The key identifying the data to retrieve.
+        prototype : BufferPrototype
+            The buffer prototype to use for reading the data.
+        byte_range : ByteRequest, optional
+            If specified, only retrieve a portion of the stored data.
+            Can be a ``RangeByteRequest``, ``OffsetByteRequest``, or ``SuffixByteRequest``.
+
+        Returns
+        -------
+        bytes
+            The raw bytes stored at the given key.
+
+        Raises
+        ------
+        FileNotFoundError
+            If the key does not exist in the store.
+
+        See Also
+        --------
+        get : Lower-level method that returns a Buffer object.
+        get_bytes : Synchronous version of this method.
+        get_json : Asynchronous method for retrieving and parsing JSON data.
+
+        Examples
+        --------
+        >>> store = await MemoryStore.open()
+        >>> await store.set("data", Buffer.from_bytes(b"hello world"))
+        >>> data = await store.get_bytes("data", prototype=default_buffer_prototype())
+        >>> print(data)
+        b'hello world'
+        """
+        buffer = await self.get(key, prototype, byte_range)
+        if buffer is None:
+            raise FileNotFoundError(key)
+        return buffer.to_bytes()
+
+    def _get_bytes_sync(
+        self, key: str = "", *, prototype: BufferPrototype, byte_range: ByteRequest | None = None
+    ) -> bytes:
+        """
+        Retrieve raw bytes from the store synchronously.
+
+        This is a synchronous wrapper around ``get_bytes()``. It should only
+        be called from non-async code. For async contexts, use ``get_bytes()``
+        instead.
+
+        Parameters
+        ----------
+        key : str, optional
+            The key identifying the data to retrieve. Defaults to an empty string.
+        prototype : BufferPrototype
+            The buffer prototype to use for reading the data.
+        byte_range : ByteRequest, optional
+            If specified, only retrieve a portion of the stored data.
+            Can be a ``RangeByteRequest``, ``OffsetByteRequest``, or ``SuffixByteRequest``.
+
+        Returns
+        -------
+        bytes
+            The raw bytes stored at the given key.
+
+        Raises
+        ------
+        FileNotFoundError
+            If the key does not exist in the store.
+
+        Warnings
+        --------
+        Do not call this method from async functions. Use ``get_bytes()`` instead
+        to avoid blocking the event loop.
+
+        See Also
+        --------
+        get_bytes : Asynchronous version of this method.
+        get_json_sync : Synchronous method for retrieving and parsing JSON data.
+
+        Examples
+        --------
+        >>> store = MemoryStore()
+        >>> await store.set("data", Buffer.from_bytes(b"hello world"))
+        >>> data = store.get_bytes_sync("data", prototype=default_buffer_prototype())
+        >>> print(data)
+        b'hello world'
+        """
+
+        return sync(self._get_bytes(key, prototype=prototype, byte_range=byte_range))
+
+    async def _get_json(
+        self, key: str, *, prototype: BufferPrototype, byte_range: ByteRequest | None = None
+    ) -> Any:
+        """
+        Retrieve and parse JSON data from the store asynchronously.
+
+        This is a convenience method that retrieves bytes from the store and
+        parses them as JSON.
+
+        Parameters
+        ----------
+        key : str
+            The key identifying the JSON data to retrieve.
+        prototype : BufferPrototype
+            The buffer prototype to use for reading the data.
+        byte_range : ByteRequest, optional
+            If specified, only retrieve a portion of the stored data.
+            Can be a ``RangeByteRequest``, ``OffsetByteRequest``, or ``SuffixByteRequest``.
+            Note: Using byte ranges with JSON may result in invalid JSON.
+
+        Returns
+        -------
+        Any
+            The parsed JSON data. This follows the behavior of ``json.loads()`` and
+            can be any JSON-serializable type: dict, list, str, int, float, bool, or None.
+
+        Raises
+        ------
+        FileNotFoundError
+            If the key does not exist in the store.
+        json.JSONDecodeError
+            If the stored data is not valid JSON.
+
+        See Also
+        --------
+        get_bytes : Method for retrieving raw bytes.
+        get_json_sync : Synchronous version of this method.
+
+        Examples
+        --------
+        >>> store = await MemoryStore.open()
+        >>> metadata = {"zarr_format": 3, "node_type": "array"}
+        >>> await store.set("zarr.json", Buffer.from_bytes(json.dumps(metadata).encode()))
+        >>> data = await store.get_json("zarr.json", prototype=default_buffer_prototype())
+        >>> print(data)
+        {'zarr_format': 3, 'node_type': 'array'}
+        """
+
+        return json.loads(await self._get_bytes(key, prototype=prototype, byte_range=byte_range))
+
+    def _get_json_sync(
+        self, key: str = "", *, prototype: BufferPrototype, byte_range: ByteRequest | None = None
+    ) -> Any:
+        """
+        Retrieve and parse JSON data from the store synchronously.
+
+        This is a synchronous wrapper around ``get_json()``. It should only
+        be called from non-async code. For async contexts, use ``get_json()``
+        instead.
+
+        Parameters
+        ----------
+        key : str, optional
+            The key identifying the JSON data to retrieve. Defaults to an empty string.
+        prototype : BufferPrototype
+            The buffer prototype to use for reading the data.
+        byte_range : ByteRequest, optional
+            If specified, only retrieve a portion of the stored data.
+            Can be a ``RangeByteRequest``, ``OffsetByteRequest``, or ``SuffixByteRequest``.
+            Note: Using byte ranges with JSON may result in invalid JSON.
+
+        Returns
+        -------
+        Any
+            The parsed JSON data. This follows the behavior of ``json.loads()`` and
+            can be any JSON-serializable type: dict, list, str, int, float, bool, or None.
+
+        Raises
+        ------
+        FileNotFoundError
+            If the key does not exist in the store.
+        json.JSONDecodeError
+            If the stored data is not valid JSON.
+
+        Warnings
+        --------
+        Do not call this method from async functions. Use ``get_json()`` instead
+        to avoid blocking the event loop.
+
+        See Also
+        --------
+        get_json : Asynchronous version of this method.
+        get_bytes_sync : Synchronous method for retrieving raw bytes without parsing.
+
+        Examples
+        --------
+        >>> store = MemoryStore()
+        >>> metadata = {"zarr_format": 3, "node_type": "array"}
+        >>> store.set("zarr.json", Buffer.from_bytes(json.dumps(metadata).encode()))
+        >>> data = store.get_json_sync("zarr.json", prototype=default_buffer_prototype())
+        >>> print(data)
+        {'zarr_format': 3, 'node_type': 'array'}
+        """
+
+        return sync(self._get_json(key, prototype=prototype, byte_range=byte_range))
+
     @abstractmethod
     async def get_partial_values(
         self,
@@ -278,7 +486,7 @@ async def _set_many(self, values: Iterable[tuple[str, Buffer]]) -> None:
         """
         Insert multiple (key, value) pairs into storage.
         """
-        await gather(*starmap(self.set, values))
+        await asyncio.gather(*starmap(self.set, values))
 
     @property
     def supports_consolidated_metadata(self) -> bool: