feature(store): V3 ZipStore

src/zarr/abc/store.py

@@ -11,6 +11,7 @@
 
 
 class AccessMode(NamedTuple):
+    str: AccessModeLiteral
     readonly: bool
     overwrite: bool
     create: bool
@@ -20,6 +21,7 @@ class AccessMode(NamedTuple):
     def from_literal(cls, mode: AccessModeLiteral) -> Self:
         if mode in ("r", "r+", "a", "w", "w-"):
             return cls(
+                str=mode,
                 readonly=mode == "r",
                 overwrite=mode == "w",
                 create=mode in ("a", "w", "w-"),
@@ -42,6 +44,14 @@ async def open(cls, *args: Any, **kwargs: Any) -> Self:
         await store._open()
         return store
 
+    def __enter__(self) -> Self:
+        """Enter a context manager that will close the store upon exiting."""
+        return self
+
+    def __exit__(self, *args: Any) -> None:
+        """Close the store."""
+        self.close()
+
     async def _open(self) -> None:
         if self._is_open:
             raise ValueError("store is already open")
@@ -143,6 +153,12 @@ async def set(self, key: str, value: Buffer) -> None:
         """
         ...
 
+    @property
+    @abstractmethod
+    def supports_deletes(self) -> bool:
+        """Does the store support deletes?"""
+        ...
+
     @abstractmethod
     async def delete(self, key: str) -> None:
         """Remove a key from the store
@@ -221,7 +237,6 @@ def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
     def close(self) -> None:
         """Close the store."""
         self._is_open = False
-        pass
 
 
 @runtime_checkable

src/zarr/store/__init__.py

@@ -2,5 +2,14 @@
 from zarr.store.local import LocalStore
 from zarr.store.memory import MemoryStore
 from zarr.store.remote import RemoteStore
+from zarr.store.zip import ZipStore
 
-__all__ = ["StorePath", "StoreLike", "make_store_path", "RemoteStore", "LocalStore", "MemoryStore"]
+__all__ = [
+    "StorePath",
+    "StoreLike",
+    "make_store_path",
+    "RemoteStore",
+    "LocalStore",
+    "MemoryStore",
+    "ZipStore",
+]

src/zarr/store/local.py

@@ -73,6 +73,7 @@ def _put(
 
 class LocalStore(Store):
     supports_writes: bool = True
+    supports_deletes: bool = True
     supports_partial_writes: bool = True
     supports_listing: bool = True
 

src/zarr/store/memory.py

@@ -18,6 +18,7 @@
 # When that is done, the `MemoryStore` will just be a store that wraps a dict.
 class MemoryStore(Store):
     supports_writes: bool = True
+    supports_deletes: bool = True
     supports_partial_writes: bool = True
     supports_listing: bool = True
 

src/zarr/store/remote.py

@@ -20,6 +20,7 @@
 class RemoteStore(Store):
     # based on FSSpec
     supports_writes: bool = True
+    supports_deletes: bool = True
     supports_partial_writes: bool = False
     supports_listing: bool = True
 

src/zarr/store/zip.py

@@ -0,0 +1,223 @@
+from __future__ import annotations
+
+import os
+import threading
+import time
+import zipfile
+from pathlib import Path
+from typing import TYPE_CHECKING, Literal
+
+from zarr.abc.store import Store
+from zarr.core.buffer import Buffer, BufferPrototype
+
+if TYPE_CHECKING:
+    from collections.abc import AsyncGenerator
+
+ZipStoreAccessModeLiteral = Literal["r", "w", "a"]
+
+
+class ZipStore(Store):
+    """
+    Storage class using a ZIP file.
+
+    Parameters
+    ----------
+    path : string
+        Location of file.
+    compression : integer, optional
+        Compression method to use when writing to the archive.
+    allowZip64 : bool, optional
+        If True (the default) will create ZIP files that use the ZIP64
+        extensions when the zipfile is larger than 2 GiB. If False
+        will raise an exception when the ZIP file would require ZIP64
+        extensions.
+    mode : string, optional
+        One of 'r' to read an existing file, 'w' to truncate and write a new
+        file, 'a' to append to an existing file, or 'x' to exclusively create
+        and write a new file.
+    """
+
+    supports_writes: bool = True
+    supports_deletes: bool = False
+    supports_partial_writes: bool = False
+    supports_listing: bool = True
+
+    path: Path
+    compression: int
+    allowZip64: bool
+
+    _zf: zipfile.ZipFile
+    _lock: threading.RLock
+
+    def __init__(
+        self,
+        path: Path | str,
+        *,
+        mode: ZipStoreAccessModeLiteral = "r",
+        compression: int = zipfile.ZIP_STORED,
+        allowZip64: bool = True,
+    ):
+        super().__init__(mode=mode)
+
+        if isinstance(path, str):
+            path = Path(path)
+        assert isinstance(path, Path)
+        self.path = path  # root?
+
+        self._zmode = mode
+        self.compression = compression
+        self.allowZip64 = allowZip64
+
+    async def _open(self) -> None:
+        if self._is_open:
+            raise ValueError("store is already open")
+
+        self._lock = threading.RLock()
+
+        self._zf = zipfile.ZipFile(
+            self.path,
+            mode=self._zmode,
+            compression=self.compression,
+            allowZip64=self.allowZip64,
+        )
+
+        self._is_open = True
+
+    def close(self) -> None:
+        super().close()
+        with self._lock:
+            self._zf.close()
+
+    async def clear(self) -> None:
+        with self._lock:
+            self._check_writable()
+            self._zf.close()
+            os.remove(self.path)
+            self._zf = zipfile.ZipFile(
+                self.path, mode="w", compression=self.compression, allowZip64=self.allowZip64
+            )
+
+    async def empty(self) -> bool:
+        with self._lock:
+            if self._zf.namelist():
+                return False
+            else:
+                return True
+
+    def __str__(self) -> str:
+        return f"zip://{self.path}"
+
+    def __repr__(self) -> str:
+        return f"ZipStore({str(self)!r})"
+
+    def __eq__(self, other: object) -> bool:
+        return isinstance(other, type(self)) and self.path == other.path
+
+    def _get(
+        self,
+        key: str,
+        prototype: BufferPrototype,
+        byte_range: tuple[int | None, int | None] | None = None,
+    ) -> Buffer | None:
+        try:
+            with self._zf.open(key) as f:  # will raise KeyError
+                if byte_range is None:
+                    return prototype.buffer.from_bytes(f.read())
+                start, length = byte_range
+                if start:
+                    if start < 0:
+                        start = f.seek(start, os.SEEK_END) + start
+                    else:
+                        start = f.seek(start, os.SEEK_SET)
+                if length:
+                    return prototype.buffer.from_bytes(f.read(length))
+                else:
+                    return prototype.buffer.from_bytes(f.read())
+        except KeyError:
+            return None
+
+    async def get(
+        self,
+        key: str,
+        prototype: BufferPrototype,
+        byte_range: tuple[int | None, int | None] | None = None,
+    ) -> Buffer | None:
+        assert isinstance(key, str)
+
+        with self._lock:
+            return self._get(key, prototype=prototype, byte_range=byte_range)
+
+    async def get_partial_values(
+        self,
+        prototype: BufferPrototype,
+        key_ranges: list[tuple[str, tuple[int | None, int | None]]],
+    ) -> list[Buffer | None]:
+        out = []
+        with self._lock:
+            for key, byte_range in key_ranges:
+                out.append(self._get(key, prototype=prototype, byte_range=byte_range))
+        return out
+
+    def _set(self, key: str, value: Buffer) -> None:
+        # generally, this should be called inside a lock
+        keyinfo = zipfile.ZipInfo(filename=key, date_time=time.localtime(time.time())[:6])
+        keyinfo.compress_type = self.compression
+        if keyinfo.filename[-1] == os.sep:
+            keyinfo.external_attr = 0o40775 << 16  # drwxrwxr-x
+            keyinfo.external_attr |= 0x10  # MS-DOS directory flag
+        else:
+            keyinfo.external_attr = 0o644 << 16  # ?rw-r--r--
+        self._zf.writestr(keyinfo, value.to_bytes())
+
+    async def set(self, key: str, value: Buffer) -> None:
+        self._check_writable()
+        assert isinstance(key, str)
+        if not isinstance(value, Buffer):
+            raise TypeError("ZipStore.set(): `value` must a Buffer instance")
+        with self._lock:
+            self._set(key, value)
+
+    async def set_partial_values(self, key_start_values: list[tuple[str, int, bytes]]) -> None:
+        raise NotImplementedError
+
+    async def delete(self, key: str) -> None:
+        raise NotImplementedError
+
+    async def exists(self, key: str) -> bool:
+        with self._lock:
+            try:
+                self._zf.getinfo(key)
+            except KeyError:
+                return False
+            else:
+                return True
+
+    async def list(self) -> AsyncGenerator[str, None]:
+        with self._lock:
+            for key in self._zf.namelist():
+                yield key
+
+    async def list_prefix(self, prefix: str) -> AsyncGenerator[str, None]:
+        async for key in self.list():
+            if key.startswith(prefix):
+                yield key
+
+    async def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
+        if prefix.endswith("/"):
+            prefix = prefix[:-1]
+
+        keys = self._zf.namelist()
+        seen = set()
+        if prefix == "":
+            keys_unique = set(k.split("/")[0] for k in keys)
+            for key in keys_unique:
+                if key not in seen:
+                    seen.add(key)
+                    yield key
+        else:
+            for key in keys:
+                if key.startswith(prefix + "/") and key != prefix:
+                    k = key.removeprefix(prefix + "/").split("/")[0]
+                    if k not in seen:
+                        seen.add(k)
+                        yield k

tests/v3/conftest.py

@@ -10,7 +10,7 @@
 from hypothesis import HealthCheck, Verbosity, settings
 
 from zarr import AsyncGroup, config
-from zarr.store import LocalStore, MemoryStore, StorePath
+from zarr.store import LocalStore, MemoryStore, StorePath, ZipStore
 from zarr.store.remote import RemoteStore
 
 if TYPE_CHECKING:
@@ -25,14 +25,16 @@
 
 
 async def parse_store(
-    store: Literal["local", "memory", "remote"], path: str
-) -> LocalStore | MemoryStore | RemoteStore:
+    store: Literal["local", "memory", "remote", "zip"], path: str
+) -> LocalStore | MemoryStore | RemoteStore | ZipStore:
     if store == "local":
         return await LocalStore.open(path, mode="w")
     if store == "memory":
         return await MemoryStore.open(mode="w")
     if store == "remote":
         return await RemoteStore.open(url=path, mode="w")
+    if store == "zip":
+        return await ZipStore.open(path + "/zarr.zip", mode="w")
     raise AssertionError
 
 
@@ -64,6 +66,11 @@ async def memory_store() -> MemoryStore:
     return await MemoryStore.open(mode="w")
 
 
+@pytest.fixture(scope="function")
+async def zip_store(tmpdir: LEGACY_PATH) -> ZipStore:
+    return await ZipStore.open(str(tmpdir / "zarr.zip"), mode="w")
+
+
 @pytest.fixture(scope="function")
 async def store(request: pytest.FixtureRequest, tmpdir: LEGACY_PATH) -> Store:
     param = request.param
@@ -73,7 +80,7 @@ async def store(request: pytest.FixtureRequest, tmpdir: LEGACY_PATH) -> Store:
 @dataclass
 class AsyncGroupRequest:
     zarr_format: ZarrFormat
-    store: Literal["local", "remote", "memory"]
+    store: Literal["local", "remote", "memory", "zip"]
     attributes: dict[str, Any] = field(default_factory=dict)
 
 

tests/v3/test_array.py

@@ -10,7 +10,7 @@
 from zarr.store.common import StorePath
 
 
-@pytest.mark.parametrize("store", ("local", "memory"), indirect=["store"])
+@pytest.mark.parametrize("store", ("local", "memory", "zip"), indirect=["store"])
 @pytest.mark.parametrize("zarr_format", (2, 3))
 @pytest.mark.parametrize("exists_ok", [True, False])
 @pytest.mark.parametrize("extant_node", ["array", "group"])
@@ -59,7 +59,7 @@ def test_array_creation_existing_node(
             )
 
 
-@pytest.mark.parametrize("store", ("local", "memory"), indirect=["store"])
+@pytest.mark.parametrize("store", ("local", "memory", "zip"), indirect=["store"])
 @pytest.mark.parametrize("zarr_format", (2, 3))
 def test_array_name_properties_no_group(
     store: LocalStore | MemoryStore, zarr_format: ZarrFormat
@@ -70,7 +70,7 @@ def test_array_name_properties_no_group(
     assert arr.basename is None
 
 
-@pytest.mark.parametrize("store", ("local", "memory"), indirect=["store"])
+@pytest.mark.parametrize("store", ("local", "memory", "zip"), indirect=["store"])
 @pytest.mark.parametrize("zarr_format", (2, 3))
 def test_array_name_properties_with_group(
     store: LocalStore | MemoryStore, zarr_format: ZarrFormat