Implement __slots__

.github/workflows/build.yaml

@@ -32,6 +32,8 @@ jobs:
         run: pip install emake
       - name: Run lint
         run: emake lint
+        env:
+          PYTHONUNBUFFERED: "1"
 
   test-image:
     name: Generate test ext4 image
@@ -49,6 +51,8 @@ jobs:
         run: |
           set -e
           ./_test_image.sh
+        env:
+          PYTHONUNBUFFERED: "1"
       - uses: actions/upload-artifact@v6
         with:
           name: test.ext4
@@ -88,6 +92,8 @@ jobs:
       - name: Run tests
         shell: bash
         run: emake test
+        env:
+          PYTHONUNBUFFERED: "1"
 
   fuzz:
     name: Fuzz
@@ -112,6 +118,8 @@ jobs:
       - name: Run test
         shell: bash
         run: make fuzz
+        env:
+          PYTHONUNBUFFERED: "1"
 
   build-sdist:
     name: Build sdist
@@ -125,6 +133,8 @@ jobs:
       - *install-emake
       - name: Building sdist
         run: emake build --sdist
+        env:
+          PYTHONUNBUFFERED: "1"
       - uses: actions/upload-artifact@v6
         with:
           name: pip-sdist
@@ -148,6 +158,8 @@ jobs:
           path: .
       - name: Test wheel
         run: emake test --wheel
+        env:
+          PYTHONUNBUFFERED: "1"
       - uses: actions/upload-artifact@v6
         with:
           name: pip-wheel-none-any
@@ -188,6 +200,8 @@ jobs:
             --arch ${{ matrix.arch }} \
             --libc ${{ matrix.libc }} \
             --python ${{ matrix.python }}
+        env:
+          PYTHONUNBUFFERED: "1"
       - name: Download test.ext4
         uses: actions/download-artifact@v8
         with:
@@ -200,6 +214,8 @@ jobs:
             --arch ${{ matrix.arch }} \
             --libc ${{ matrix.libc }} \
             --python ${{ matrix.python }}
+        env:
+          PYTHONUNBUFFERED: "1"
       - uses: actions/upload-artifact@v6
         with:
           name: pip-wheel-${{ matrix.python }}-${{ matrix.arch }}-${{ matrix.libc }}

ext4/block.py

@@ -1,7 +1,10 @@
 import errno
 import io
 import os
-from typing import TYPE_CHECKING
+from typing import (
+    TYPE_CHECKING,
+    final,
+)
 
 from ._compat import override
 
@@ -11,7 +14,10 @@
     from .volume import Volume
 
 
+@final
 class BlockIOBlocks:
+    __slots__ = ("blockio", "_null_block")
+
     def __init__(self, blockio: "BlockIO") -> None:
         self.blockio: BlockIO = blockio
         self._null_block: bytearray = bytearray(self.block_size)
@@ -41,7 +47,10 @@ def __getitem__(self, ee_block: int) -> bytearray | bytes:
         return self._null_block
 
 
+@final
 class BlockIO(io.RawIOBase):
+    __slots__ = ("inode", "cursor", "blocks")
+
     def __init__(self, inode: "Inode") -> None:
         super().__init__()
         self.inode: Inode = inode

ext4/blockdescriptor.py

@@ -21,6 +21,8 @@
 
 @final
 class BlockDescriptor(Ext4Struct):
+    __slots__ = ("bg_no",)
+
     _pack_ = 1
     # _anonymous_ = ("bg_reserved",)
     _fields_ = [

ext4/directory.py

@@ -28,6 +28,8 @@
 
 
 class DirectoryEntryStruct(Ext4Struct):
+    __slots__: tuple[str, ...] = ("directory",)
+
     def __init__(self, directory: "Directory", offset: int) -> None:
         self.directory: Directory = directory
         super().__init__(directory.volume, offset)
@@ -39,6 +41,7 @@ def read_from_volume(self) -> None:
 
 
 class DirectoryEntryBase(DirectoryEntryStruct):
+    __slots__: tuple[str, ...] = ()
     @property
     def name_bytes(self) -> bytes:
         return bytes(self.name)[: self.name_len]  # pyright: ignore[reportAny]
@@ -55,6 +58,7 @@ def is_fake_entry(self) -> bool:
 
 @final
 class DirectoryEntry(DirectoryEntryBase):
+    __slots__ = ()
     _pack_ = 1
     # _anonymous_ = ("l_i_reserved",)
     _fields_ = [
@@ -67,6 +71,7 @@ class DirectoryEntry(DirectoryEntryBase):
 
 @final
 class DirectoryEntry2(DirectoryEntryBase):
+    __slots__ = ()
     _pack_ = 1
     # _anonymous_ = ("l_i_reserved",)
     _fields_ = [
@@ -85,6 +90,7 @@ def is_fake_entry(self) -> bool:
 
 @final
 class DirectoryEntryTail(DirectoryEntryStruct):
+    __slots__ = ()
     _pack_ = 1
     # _anonymous_ = ("det_reserved_zero1", "det_reserved_zero2",)
     _fields_ = [
@@ -107,6 +113,7 @@ def expected_magic(self) -> int:
 
 @final
 class DirectoryEntryHash(DirectoryEntryStruct):
+    __slots__ = ()
     _pack_ = 1
     # _anonymous_ = ("det_reserved_zero1", "det_reserved_zero2",)
     _fields_ = [

ext4/extent.py

@@ -20,7 +20,10 @@
     from .volume import Volume
 
 
+@final
 class ExtentBlocks:
+    __slots__: tuple[str, ...] = ("extent", "_null_block")
+
     def __init__(self, extent: "Extent") -> None:
         self.extent: Extent = extent
         self._null_block: bytearray = bytearray(self.block_size)
@@ -74,6 +77,8 @@ def __len__(self) -> int:
 
 @final
 class ExtentHeader(Ext4Struct):
+    __slots__ = ("tree", "indices", "extents", "tail")
+
     _pack_ = 1
     # _anonymous_ = ()
     _fields_ = [
@@ -153,6 +158,8 @@ def checksum(self) -> int | None:
 
 @final
 class ExtentIndex(Ext4Struct):
+    __slots__ = ("ei_no", "header")
+
     _pack_ = 1
     # _anonymous_ = ("ei_unused",)
     _fields_ = [
@@ -184,6 +191,8 @@ def inode(self) -> "Inode":
 
 @final
 class Extent(Ext4Struct):
+    __slots__ = ("ee_no", "header", "blocks")
+
     _pack_ = 1
     # _anonymous_ = ("ei_unused",)
     _fields_ = [
@@ -231,6 +240,8 @@ def read(self) -> bytes:
 
 @final
 class ExtentTail(Ext4Struct):
+    __slots__ = ("header",)
+
     _pack_ = 1
     _fields_ = [
         ("et_checksum", c_uint32),
@@ -250,6 +261,8 @@ def inode(self) -> "Inode":
 
 
 class ExtentTree:
+    __slots__: tuple[str, ...] = ("inode", "headers")
+
     def __init__(self, inode: "Inode") -> None:
         self.inode: Inode = inode
         self.headers: list[ExtentHeader] = []

ext4/htree.py

@@ -31,6 +31,8 @@
 
 
 class LittleEndianStructureWithVolume(LittleEndianStructure):
+    __slots__: tuple[str, ...] = ("_volume",)
+
     def __init__(self) -> None:
         super().__init__()
         self._volume: Volume | None = None
@@ -47,6 +49,8 @@ def volume(self, volume: "Volume") -> None:
 
 @final
 class DotDirectoryEntry2(LittleEndianStructureWithVolume):
+    __slots__ = ()
+
     _pack_ = 1
     # _anonymous_ = ()
     _fields_ = [
@@ -88,6 +92,8 @@ class DXRootInfo(LittleEndianStructure):
 
 
 class DXBase(Ext4Struct):
+    __slots__: tuple[str, ...] = ("directory",)
+
     def __init__(self, directory: "Directory", offset: int) -> None:
         self.directory: Directory = directory
         super().__init__(directory.volume, offset)
@@ -102,6 +108,8 @@ def read_from_volume(self) -> None:
 
 @final
 class DXEntry(DXBase):
+    __slots__ = ("index", "parent")
+
     _pack_ = 1
     # _anonymous_ = ("")
     _fields_ = [
@@ -119,6 +127,8 @@ def __init__(self, parent: "DXEntriesBase", index: int) -> None:
 
 
 class DXEntriesBase(DXBase):
+    __slots__: tuple[str, ...] = ()
+
     @override
     def read_from_volume(self) -> None:
         super().read_from_volume()
@@ -141,6 +151,8 @@ def info_length(self) -> int:
 
 @final
 class DXRoot(DXEntriesBase):
+    __slots__ = ()
+
     _pack_ = 1
     # _anonymous_ = ("")
     _fields_ = [
@@ -178,6 +190,8 @@ def magic(self) -> int:
 
 @final
 class DXNode(DXEntriesBase):
+    __slots__ = ()
+
     _pack_ = 1
     # _anonymous_ = ("")
     _fields_ = [
@@ -196,6 +210,8 @@ def __init__(self, directory: "Directory", offset: int) -> None:
 
 @final
 class DXTail(DXBase):
+    __slots__ = ("parent",)
+
     _pack_ = 1
     # _anonymous_ = ("dt_reserved")
     _fields_ = [

ext4/inode.py

@@ -162,6 +162,7 @@ class Osd2(LittleEndianUnion):
 class Inode(Ext4Struct):
     EXT4_GOOD_OLD_INODE_SIZE: int = 128
     EXT2_GOOD_OLD_INODE_SIZE: int = 128
+    __slots__: tuple[str, ...] = ("i_no", "tree")
     _pack_ = 1  # pyright: ignore[reportUnannotatedClassAttribute]
     _fields_ = [  # pyright: ignore[reportUnannotatedClassAttribute]
         ("i_mode", MODE.basetype),
@@ -451,26 +452,32 @@ def xattrs(
                     raise
 
 
+@final
 class UnknownInode(Inode):
-    pass
+    __slots__ = ()
 
 
+@final
 class Fifo(Inode):
-    pass
+    __slots__ = ()
 
 
+@final
 class CharacterDevice(Inode):
-    pass
+    __slots__ = ()
 
 
+@final
 class BlockDevice(Inode):
-    pass
+    __slots__ = ()
 
 
+@final
 class Socket(Inode):
-    pass
+    __slots__ = ()
 
 
+@final
 class File(Inode):
     @override
     def open(
@@ -479,7 +486,10 @@ def open(
         return self._open(mode, encoding, newline)
 
 
+@final
 class SymbolicLink(Inode):
+    __slots__ = ()
+
     @property
     def is_fast_symlink(self) -> bool:
         i_blocks_lo = assert_cast(self.i_blocks_lo, int)  # pyright: ignore[reportAny]
@@ -498,7 +508,10 @@ def readlink(self) -> bytes:
         return self.volume.read(self.i_size)
 
 
+@final
 class Directory(Inode):
+    __slots__ = ("_inode_at_cache", "_dirents", "htree")
+
     def __init__(self, volume: Volume, offset: int, i_no: int) -> None:
         super().__init__(volume, offset, i_no)
         self._inode_at_cache: LRUCache[str | bytes, Inode] = LRUCache(maxsize=32)

ext4/struct.py

@@ -74,6 +74,8 @@ def to_hex(data: int | list[int] | bytes | None) -> str:
 
 
 class Ext4Struct(LittleEndianStructure):
+    __slots__: tuple[str, ...] = ("volume", "offset")
+
     def __init__(self, volume: "Volume", offset: int) -> None:
         super().__init__()
         self.volume: Volume = volume

ext4/superblock.py

@@ -37,6 +37,8 @@
 
 @final
 class Superblock(Ext4Struct):
+    __slots__ = ()
+
     _pack_ = 1
     # _anonymous_ = (
     #     "s_reserved_pad",