Correctly deal with a controller returning None

[invirt/packages/python-routefs.git] / routefs / __init__.py

diff --git a/routefs/__init__.py b/routefs/__init__.py
index 875345b..c3b0357 100644 (file)
--- a/routefs/__init__.py
+++ b/routefs/__init__.py
@@ -83,9 +83,11 @@ class RouteFS(fuse.Fuse):
         """
         match = self.map.match(path)
         if match is None:
-            return
+            return NoEntry()
         controller = match.pop('controller')
         result = getattr(self, controller)(**match)
+        if result is None:
+            return NoEntry()
         if type(result) is str:
             result = File(result)
         if type(result) is list:
@@ -97,12 +99,7 @@ class RouteFS(fuse.Fuse):
         If the path referred to is a directory, return the elements of
         that diectory
         """
-        obj = self._get_file(path)
-        if type(obj) is not Directory:
-            return
-        else:
-            for member in ['.', '..'] + obj:
-                yield fuse.Direntry(str(member))
+        return self._get_file(path).readdir(offset)
     
     def getattr(self, path):
         """
@@ -111,51 +108,42 @@ class RouteFS(fuse.Fuse):
         The stat information for a directory, symlink, or file is
         predetermined based on which it is.
         """
-        obj = self._get_file(path)
-        if obj is None:
-            return -errno.ENOENT
-        
-        st = RouteStat()
-        if type(obj) is Directory:
-            st.st_mode = stat.S_IFDIR | obj.mode
-            st.st_nlink = 2
-        elif type(obj) is Symlink:
-            st.st_mode = stat.S_IFLNK | obj.mode
-            st.st_nlink = 1
-            st.st_size = len(obj)
-        else:
-            st.st_mode = stat.S_IFREG | obj.mode
-            st.st_nlink = 1
-            st.st_size = len(obj)
-        
-        return st
+        return self._get_file(path).getattr()
     
     def read(self, path, length, offset):
         """
         If the path specified is a file, return the requested portion
         of the file
         """
-        obj = self._get_file(path)
-        if obj is None:
-            return -errno.ENOENT
-        elif type(obj) in (Directory, Symlink):
-            return -errno.EINVAL
-        else:
-            return obj[offset:offset + length]
+        return self._get_file(path).read(length, offset)
     
     def readlink(self, path):
         """
         If the path specified is a symlink, return the target
         """
-        obj = self._get_file(path)
-        if obj is None:
-            return -errno.ENOENT
-        elif type(obj) is not Symlink:
-            return -errno.EINVAL
-        else:
-            return obj
+        return self._get_file(path).readlink()
+
+class TreeKey(object):
+    def getattr(self):
+        return -errno.EINVAL
+    def readdir(self, offset):
+        return -errno.EINVAL
+    def read(self, length, offset):
+        return -errno.EINVAL
+    def readlink(self):
+        return -errno.EINVAL
 
-class TreeEntry(object):
+class NoEntry(TreeKey):
+    def getattr(self):
+        return -errno.ENOENT
+    def readdir(self, offset):
+        return -errno.ENOENT
+    def read(self, length, offset):
+        return -errno.ENOENT
+    def readlink(self):
+        return -errno.ENOENT
+
+class TreeEntry(TreeKey):
     default_mode = 0444
     
     def __new__(cls, contents, mode=None):
@@ -176,18 +164,48 @@ class Directory(TreeEntry, list):
     """
     default_mode = 0555
 
+    def getattr(self):
+        st = RouteStat()
+        st.st_mode = stat.S_IFDIR | self.mode
+        st.st_nlink = 2
+        return st
+
+    def readdir(self, offset):
+        for member in ['.', '..'] + self:
+            yield fuse.Direntry(str(member))
+
 class Symlink(TreeEntry, str):
     """
     A dummy class representing something that should be a symlink
     """
     default_mode = 0777
 
+    def getattr(self):
+        st = RouteStat()
+        st.st_mode = stat.S_IFLNK | self.mode
+        st.st_nlink = 1
+        st.st_size = len(self)
+        return st
+
+    def readlink(self):
+        return self
+
 class File(TreeEntry, str):
     """
     A dummy class representing something that should be a file
     """
     default_mode = 0444
 
+    def getattr(self):
+        st = RouteStat()
+        st.st_mode = stat.S_IFREG | self.mode
+        st.st_nlink = 1
+        st.st_size = len(self)
+        return st
+
+    def read(self, length, offset):
+        return self[offset:offset + length]
+
 def main(cls):
     """
     A convenience function for initializing a RouteFS filesystem