[feature] Add overrides decorator

Author: mxmlnkn

.github/workflows/tests.yml

@@ -78,6 +78,8 @@ jobs:
         - os: ubuntu-22.04
           python-version: '3.8'
 
+    env:
+      MFUSEPY_CHECK_OVERRIDES: 1
     defaults:
       run:
         # This is especially important for windows because it seems to default to powershell
@@ -127,6 +129,13 @@ jobs:
         run: |
           python3 -c 'import mfusepy'
 
+      - name: Examples
+        run: |
+          # Simply parsing the source runs the @overrides check!
+          for file in examples/*.py; do
+              python3 "$file" -h
+          done
+
       - name: Unit Tests (FUSE 2)
         if: startsWith( matrix.os, 'ubuntu' )
         run: |

examples/context.py

@@ -5,17 +5,19 @@
 import logging
 import stat
 import time
+from typing import Any, Dict, Optional
 
-import mfusepy
+import mfusepy as fuse
 
 
-class Context(mfusepy.Operations):
+class Context(fuse.Operations):
     'Example filesystem to demonstrate fuse_get_context()'
 
-    def getattr(self, path, fh=None):
-        uid, gid, pid = mfusepy.fuse_get_context()
+    @fuse.overrides(fuse.Operations)
+    def getattr(self, path: str, fh: Optional[int] = None):
+        uid, gid, pid = fuse.fuse_get_context()
         if path == '/':
-            st = {'st_mode': (stat.S_IFDIR | 0o755), 'st_nlink': 2}
+            st: Dict[str, Any] = {'st_mode': (stat.S_IFDIR | 0o755), 'st_nlink': 2}
         elif path == '/uid':
             size = len(f'{uid}\n')
             st = {'st_mode': (stat.S_IFREG | 0o444), 'st_size': size}
@@ -26,12 +28,13 @@ def getattr(self, path, fh=None):
             size = len(f'{pid}\n')
             st = {'st_mode': (stat.S_IFREG | 0o444), 'st_size': size}
         else:
-            raise mfusepy.FuseOSError(errno.ENOENT)
+            raise fuse.FuseOSError(errno.ENOENT)
         st['st_ctime'] = st['st_mtime'] = st['st_atime'] = time.time()
         return st
 
-    def read(self, path, size, offset, fh):
-        uid, gid, pid = mfusepy.fuse_get_context()
+    @fuse.overrides(fuse.Operations)
+    def read(self, path: str, size: int, offset: int, fh: int) -> bytes:
+        uid, gid, pid = fuse.fuse_get_context()
 
         def encoded(x):
             return (f'{x}\n').encode()
@@ -45,7 +48,8 @@ def encoded(x):
 
         raise RuntimeError(f'unexpected path: {path!r}')
 
-    def readdir(self, path, fh):
+    @fuse.overrides(fuse.Operations)
+    def readdir(self, path: str, fh: int):
         return ['.', '..', 'uid', 'gid', 'pid']
 
 
@@ -55,7 +59,7 @@ def cli(args=None):
     args = parser.parse_args(args)
 
     logging.basicConfig(level=logging.DEBUG)
-    mfusepy.FUSE(Context(), args.mount, foreground=True, ro=True)
+    fuse.FUSE(Context(), args.mount, foreground=True, ro=True)
 
 
 if __name__ == '__main__':

examples/ioctl.py

@@ -42,7 +42,8 @@ def __init__(self):
             'st_nlink': 2,
         }
 
-    def create(self, path, mode, fi=None):
+    @fuse.overrides(fuse.Operations)
+    def create(self, path: str, mode, fi=None) -> int:
         self.files[path] = {
             'st_mode': (stat.S_IFREG | mode),
             'st_nlink': 1,
@@ -55,13 +56,15 @@ def create(self, path, mode, fi=None):
         self.fd += 1
         return self.fd
 
-    def getattr(self, path, fh=None):
+    @fuse.overrides(fuse.Operations)
+    def getattr(self, path: str, fh=None):
         if path not in self.files:
             raise fuse.FuseOSError(errno.ENOENT)
 
         return self.files[path]
 
-    def ioctl(self, path, cmd, arg, fh, flags, data):
+    @fuse.overrides(fuse.Operations)
+    def ioctl(self, path: str, cmd, arg, fh, flags, data) -> int:
         M_IOWR = IOWR(ord('M'), 1, ctypes.c_uint32)
         if cmd == M_IOWR:
             inbuf = ctypes.create_string_buffer(4)
@@ -74,14 +77,17 @@ def ioctl(self, path, cmd, arg, fh, flags, data):
             raise fuse.FuseOSError(errno.ENOTTY)
         return 0
 
-    def open(self, path, flags):
+    @fuse.overrides(fuse.Operations)
+    def open(self, path: str, flags) -> int:
         self.fd += 1
         return self.fd
 
-    def read(self, path, size, offset, fh):
+    @fuse.overrides(fuse.Operations)
+    def read(self, path: str, size, offset, fh) -> bytes:
         return self.data[path][offset : offset + size]
 
-    def readdir(self, path, fh):
+    @fuse.overrides(fuse.Operations)
+    def readdir(self, path: str, fh):
         return ['.', '..'] + [x[1:] for x in self.files if x != '/']
 
 

examples/loopback.py

@@ -29,6 +29,7 @@ def __init__(self, root):
         self.rwlock = threading.Lock()
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def access(self, path, amode):
         if not os.access(path, amode):
             raise fuse.FuseOSError(errno.EACCES)
@@ -37,21 +38,25 @@ def access(self, path, amode):
     chown = static_with_root_path(os.chown)
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def create(self, path, mode, fi=None):
         return os.open(path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, mode)
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def flush(self, path, fh):
         return os.fsync(fh)
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def fsync(self, path, datasync, fh):
         if datasync != 0:
             return os.fdatasync(fh)
         return os.fsync(fh)
 
     @fuse.log_callback
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def getattr(self, path, fh=None):
         st = os.lstat(path)
         return {
@@ -60,6 +65,7 @@ def getattr(self, path, fh=None):
         }
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def link(self, target, source):
         return os.link(self.root + source, target)
 
@@ -68,28 +74,33 @@ def link(self, target, source):
     open = static_with_root_path(os.open)
 
     @with_root_path
-    def read(self, path, size, offset, fh):
+    @fuse.overrides(fuse.Operations)
+    def read(self, path, size, offset, fh) -> bytes:
         with self.rwlock:
             os.lseek(fh, offset, 0)
             return os.read(fh, size)
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def readdir(self, path, fh):
         return ['.', '..', *os.listdir(path)]
 
     readlink = static_with_root_path(os.readlink)
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def release(self, path, fh):
         return os.close(fh)
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def rename(self, old, new):
         return os.rename(old, self.root + new)
 
     rmdir = static_with_root_path(os.rmdir)
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def statfs(self, path):
         stv = os.statvfs(path)
         return {
@@ -109,19 +120,22 @@ def statfs(self, path):
         }
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def symlink(self, target, source):
         return os.symlink(source, target)
 
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def truncate(self, path, length, fh=None):
-        with open(path, 'r+') as f:
+        with open(path, 'rb+') as f:
             f.truncate(length)
 
     unlink = static_with_root_path(os.unlink)
     utimens = static_with_root_path(os.utime)
 
     @fuse.log_callback
     @with_root_path
+    @fuse.overrides(fuse.Operations)
     def write(self, path, data, offset, fh):
         with self.rwlock:
             os.lseek(fh, offset, 0)