Import first working version

[fuse-aexplorer.git] / AEpy / FuseCache.py

diff --git a/AEpy/FuseCache.py b/AEpy/FuseCache.py
new file mode 100644 (file)
index 0000000..420b992
--- /dev/null
+++ b/AEpy/FuseCache.py
@@ -0,0 +1,66 @@
+from stat import S_IFDIR
+
+
+class FuseCache():
+    def __init__(self):
+        # Initialize virtual root
+        self.cache = {}
+
+    # Cache tuple:
+    # (dict of attrs, dict of children in folder)
+
+
+    def getattr(self, path):
+        paths = [p for p in path.split('/') if len(p) > 0]
+        #print(paths)
+
+        # Virtual root
+        st = dict(st_mode=(S_IFDIR | 0o755), st_nlink=2)
+
+        c = self.cache
+        for p in paths:
+            if c == None:
+                return None
+
+            if p not in c:
+                return None
+
+            (st, c) = c[p]
+
+        return st
+
+
+    def getkids(self, path):
+        paths = [p for p in path.split('/') if len(p) > 0]
+
+        c = self.cache
+        for p in paths:
+            if c == None:
+                return None
+
+            if p not in c:
+                return None
+
+            (_, c) = c[p]
+
+        return c
+
+
+    # Set a cache node's children and their attributes.
+    # This implicitly purges any prvious children from the cache.
+    # Thus, those directories will be re-scanned next time.
+    def setkids(self, path, children):
+        paths = [p for p in path.split('/') if len(p) > 0]
+
+        c = self.cache
+        for p in paths:
+            # We expect to be able to walk the path, because we can't get
+            # there without Linux' VFS stat'ing all directories leading up.
+            parent = c
+            (_, c) = c[p]
+
+        if (c == self.cache):
+            self.cache = children
+        else:
+            (st, _) = parent[p]
+            parent[p] = (st, children)