feat(utils): add readable, writable, and seekable functions to File c…

…lass.

These functions are required for pyFatFS to work.

unblob/file_utils.py

@@ -41,18 +41,23 @@ class SeekError(ValueError):
 
 
 class File(mmap.mmap):
+    access: int
+
     @classmethod
     def from_bytes(cls, content: bytes):
         m = cls(-1, len(content))
         m.write(content)
         m.seek(0)
+        m.access = mmap.ACCESS_WRITE
         return m
 
     @classmethod
     def from_path(cls, path: Path, access=mmap.ACCESS_READ):
         mode = "r+b" if access == mmap.ACCESS_WRITE else "rb"
         with path.open(mode) as base_file:
-            return cls(base_file.fileno(), 0, access=access)
+            m = cls(base_file.fileno(), 0, access=access)
+            m.access = access
+            return m
 
     def seek(self, pos: int, whence: int = os.SEEK_SET) -> int:
         try:
@@ -81,6 +86,15 @@ def __enter__(self):
     def __exit__(self, _exc_type, _exc_val, _exc_tb):
         self.close()
 
+    def readable(self) -> bool:
+        return self.access in (mmap.ACCESS_READ, mmap.ACCESS_COPY)
+
+    def writable(self) -> bool:
+        return self.access in (mmap.ACCESS_WRITE, mmap.ACCESS_COPY)
+
+    def seekable(self) -> bool:
+        return True  # Memory-mapped files are always seekable
+
 
 class OffsetFile:
     def __init__(self, file: File, offset: int):

vulture_whitelist.py

@@ -32,6 +32,9 @@
 
 unblob.plugins.hookimpl
 File.from_bytes
+File.readable
+File.writable
+File.seekable
 FileSystem.open
 
 iterbits