memfs: support per-instance store (#70)

src/dvc_objects/fs/implementations/memory.py

@@ -1,24 +1,22 @@
-import threading
-
-from funcy import cached_property, wrap_prop
-
 from ..base import FileSystem
 
 
 class MemoryFileSystem(FileSystem):  # pylint:disable=abstract-method
     protocol = "memory"
     PARAM_CHECKSUM = "md5"
 
-    def __eq__(self, other):
-        # NOTE: all fsspec MemoryFileSystem instances are equivalent and use a
-        # single global store
-        return isinstance(other, type(self))
+    def __init__(self, global_store=True, **kwargs):
+        from fsspec.implementations.memory import MemoryFileSystem as MemFS
 
-    __hash__ = FileSystem.__hash__
+        super().__init__(**kwargs)
+        self.fs = fs = MemFS(**self.fs_args)
+        if not global_store:
+            fs.store = {}
+            fs.pseudo_dirs = [""]
 
-    @wrap_prop(threading.Lock())
-    @cached_property
-    def fs(self):
-        from fsspec.implementations.memory import MemoryFileSystem as MemFS
+    def __eq__(self, other):
+        return (
+            isinstance(other, type(self)) and self.fs.store is other.fs.store
+        )
 
-        return MemFS(**self.fs_args)
+    __hash__ = FileSystem.__hash__

tests/conftest.py

@@ -100,10 +100,4 @@ def tmp_upath(request):
 
 @pytest.fixture(autouse=True)
 def memfs():
-    fs = MemoryFileSystem()
-    store = fs.fs.store
-    assert not store
-    try:
-        yield fs
-    finally:
-        store.clear()
+    return MemoryFileSystem(global_store=False)