Work in progress for memoryfs, cleaned up exception error codes

fs/browsewin.py

@@ -58,7 +58,13 @@ class BrowseFrame(wx.Frame):
         
         for is_dir, new_path in paths:
             
-            name = fs.pathsplit(new_path)[-1]            
+            name = fs.pathsplit(new_path)[-1]
+            
+            if not is_dir and name.endswith('.txt'):
+                
+                txt = self.fs.open(new_path).read(50)
+                name += " - "+txt
+            
             new_item = self.tree.AppendItem(item_id, name, data=wx.TreeItemData({'path':new_path, 'expanded':False}))
 
             if is_dir:

fs/fs.py

@@ -4,6 +4,36 @@ import fnmatch
 from itertools import chain
 
 
+error_msgs = {
+
+    "UNKNOWN_ERROR" :   "No information on error: %(path)s",
+    "INVALID_PATH" :    "Path is invalid: %(path)s",
+    "NO_DIR" :          "Directory does not exist: %(path)s",
+    "NO_FILE" :         "No such file: %(path)s",
+    "LISTDIR_FAILED" :  "Unable to get directory listing: %(path)s",
+    "NO_SYS_PATH" :     "No mapping to OS filesytem: %(path)s,",
+    "DIR_EXISTS" :      "Directory exists (try allow_recreate=True): %(path)s",
+    "OPEN_FAILED" :     "Unable to open file: %(path)s"
+}
+
+error_codes = error_msgs.keys()
+
+class FSError(Exception):
+
+    def __init__(self, code, path=None, msg=None, details=None):
+
+        self.code = code
+        self.msg = msg or error_msgs.get(code, error_msgs['UNKNOWN_ERROR'])
+        self.path = path
+        self.details = details
+
+    def __str__(self):
+
+        msg = self.msg % dict((k, str(v)) for k,v in self.__dict__.iteritems())
+
+        return '%s %s' % (self.code, msg)
+
+
 class NullFile:
 
     def __init__(self):
@@ -47,23 +77,9 @@ class NullFile:
 
 
 
-class FSError(Exception):
-
-    def __init__(self, code, msg, path=None, details=None):
-
-        self.code = code
-        self.msg = msg
-        self.path = path
-        self.details = details
-
-    def __str__(self):
-
-        msg = self.msg % self.__dict__
-
-        return '%s - %s' % (self.code, msg)
 
 
-def _isabsolute(path):
+def isabsolutepath(path):
     if path:
         return path[1] in '\\/'
     return False
@@ -89,7 +105,7 @@ def pathjoin(*paths):
     for component in chain(*(normpath(path).split('/') for path in relpaths)):
         if component == "..":
             if not pathstack:
-                raise PathError("INVALID_PATH", "Relative path is invalid: %(path)s", str(paths))
+                raise PathError("INVALID_PATH", str(paths))
             sub = pathstack.pop()
         elif component == ".":
             pass
@@ -172,14 +188,14 @@ class FS(object):
         return pathname
 
 
-    def open(self, pathname, mode, **kwargs):
+    def open(self, pathname, mode="r", buffering=-1, **kwargs):
 
         pass
 
     def open_dir(self, dirname):
 
         if not self.exists(dirname):
-            raise FSError("NO_DIR", "Directory does not exist: %(path)s", dirname)
+            raise FSError("NO_DIR", dirname)
 
         sub_fs = SubFS(self, dirname)
         return sub_fs
@@ -233,7 +249,7 @@ class SubFS(FS):
 
         return self.parent.getsyspath(self._delegate(pathname))
 
-    def open(self, pathname, mode="r", buffering=-1):
+    def open(self, pathname, mode="r", buffering=-1, **kwargs):
 
         return self.parent.open(self._delegate(pathname), mode, buffering)
 
@@ -253,9 +269,9 @@ class OSFS(FS):
         expanded_path = normpath(os.path.expanduser(root_path))
         
         if not os.path.exists(expanded_path):
-            raise FSError("PATH_NOT_EXIST", "Root path does not exist: %(path)s", expanded_path)
+            raise FSError("NO_DIR", expanded_path, msg="Root directory does not exist: %(path)s")
         if not os.path.isdir(expanded_path):
-            raise FSError("PATH_NOT_DIR", "Root path is not a directory: %(path)s", expanded_path)
+            raise FSError("NO_DIR", expanded_path, msg="Root path is not a directory: %(path)s")
         
         self.root_path = normpath(os.path.abspath(expanded_path))
         #print "Root path", self.root_path
@@ -272,12 +288,12 @@ class OSFS(FS):
 
 
 
-    def open(self, pathname, mode="r", buffering=-1):
+    def open(self, pathname, mode="r", buffering=-1, **kwargs):
 
         try:
             f = open(self.getsyspath(pathname), mode, buffering)
         except IOError, e:
-            raise FSError("OPEN_FAILED", str(e), pathname, details=e)
+            raise FSError("OPEN_FAILED", pathname, details=e, msg=str(details))
 
         return f
 
@@ -305,7 +321,7 @@ class OSFS(FS):
         try:
             paths = os.listdir(self.getsyspath(path))
         except IOError, e:
-            raise FSError("LIST_FAILED", str(e), path, details=e)
+            raise FSError("LISTDIR_FAILED", path, details=e, msg="Unable to get directory listing: %(path)s - (%(details)s)")
 
         return self._listdir_helper(path, paths, wildcard, full, absolute, hidden, dirs_only, files_only)
 
@@ -361,7 +377,7 @@ class MountFS(FS):
     def mkdir(self, dirpath, recursive=True):
 
         if recursive and '/' in dirpath:
-            raise PathError("INVALID_PATH", "Use recursive=True to create this path", dirpath)
+            raise PathError("NO_DIR", dirpath, msg="Use recursive=True to create this path: %(path)s")
 
         def do_mkdir(dirname):
 
@@ -375,7 +391,7 @@ class MountFS(FS):
 
             if path_component in current_dir:
                 if not current_dir[path_component].isdir():
-                    raise PathError("INVALID_PATH", "Can not create path here", dirpath)
+                    raise PathError("NO_DIR", dirpath, msg="Path references a file, not a dir: %(path)s")
 
             current_dir[path_component] = DirEntry(TYPE_DIR, path_component, {})
             current_dir = current_dir[path_component].contents
@@ -386,7 +402,7 @@ class MountFS(FS):
     def mountdir(self, dirname, dirfs, params=None, create_path=True):
 
         if dirname in self.dir_mounts:
-            raise FSError("MOUNT_NOT_FREE", "A directory of this name is already mounted", dirname)
+            raise FSError("MOUNT_NOT_FREE", dirname, msg="A directory of this name is already mounted")
 
         success, code = dirfs._onmount(self)
         if success:

fs/memoryfs.py

@@ -37,8 +37,13 @@ class MemoryFile(object):
                 
         if check_mode('a'):
             self.mem_file.seek(0, os.SEEK_END)
-                
-        self.mem_file = None    
+    
+        self.closed = False
+        
+    def __del__(self):
+        if not self.closed:
+            self.close()
+    
         
     def flush(self):
         pass
@@ -53,9 +58,11 @@ class MemoryFile(object):
         return self.mem_file.readline(*args, **kwargs)
     
     def close(self):        
-        value = self.get_vale()
-        self.memory_fs._on_close_memory_file(path, value)
-        StringIO.close(self)
+        value = self.mem_file.getvalue()
+        if 'w' in self.mode:
+            self.memory_fs._on_close_memory_file(self.path, value)
+        self.mem_file.close()
+        self.closed = True
         
     def read(self, size=None):
         return self.mem_file.read(size)
@@ -100,9 +107,11 @@ class MemoryFS(FS):
             self.locks = 0
             
         def lock(self):
+            return
             self.locks += 1
             
         def unlock(self):
+            return
             self.locks -=1
             assert self.locks >=0, "Lock / Unlock mismatch!"
             
@@ -144,21 +153,18 @@ class MemoryFS(FS):
     def _get_dir_entry(self, dirpath):
                 
         current_dir = self.root
-        
-        #print _iteratepath(dirpath)        
+                
         for path_component in _iteratepath(dirpath):
             dir_entry = current_dir.contents.get(path_component, None)
             if dir_entry is None:
-                return None
-            if not dir_entry.isdir():
-                return None
+                return None            
             current_dir = dir_entry
             
         return current_dir
     
     def getsyspath(self, pathname):
         
-        raise FSError("NO_SYS_PATH", "This file-system has no syspath", pathname)
+        raise FSError("NO_SYS_PATH", pathname, msg="This file-system has no syspath")
     
             
     def isdir(self, path):
@@ -188,11 +194,11 @@ class MemoryFS(FS):
             parent_dir = self._get_dir_entry(dirpath)
             if parent_dir is not None:
                 if parent_dir.isfile():                    
-                    raise FSError("CANNOT_CREATE_DIR", "Can not create a directory, because path references a file: %(path)s", dirname)
+                    raise FSError("NO_DIR", dirname, msg="Can not create a directory, because path references a file: %(path)s")
                 else:                    
                     if not allow_recreate:
                         if dirname in parent_dir.contents:
-                            raise FSError("CANNOT_RECREATE_DIR", "Can not create a directory that already exists (try allow_recreate=True): %(path)s", dirname)
+                            raise FSError("NO_DIR", dirname, msg="Can not create a directory that already exists (try allow_recreate=True): %(path)s")
             
             current_dir = self.root
             for path_component in _iteratepath(dirpath)[:-1]:
@@ -200,7 +206,7 @@ class MemoryFS(FS):
                 if dir_item is None:
                     break
                 if not dir_item.isdir():
-                    raise FSError("CANNOT_CREATE_DIR", "Can not create a directory, because path references a file: %(path)s", dirname)
+                    raise FSError("NO_DIR", dirname, msg="Can not create a directory, because path references a file: %(path)s")
                 current_dir = dir_item.contents
                 
             current_dir = self.root            
@@ -218,15 +224,15 @@ class MemoryFS(FS):
         else:                
             parent_dir = self._get_dir_entry(dirpath)            
             if parent_dir is None:
-                raise FSError("NO_DIR", "Could not make dir, as parent dir does not exist: %(path)s", dirname )
+                raise FSError("NO_DIR", dirname, msg="Could not make dir, as parent dir does not exist: %(path)s")
         
         dir_item = parent_dir.contents.get(dirname, None)        
         if dir_item is not None:            
             if dir_item.isdir():
                 if not allow_recreate:
-                    raise FSError("CANNOT_RECREATE_DIR", "Can not create a directory that already exists (try allow_recreate=True): %(path)s", dirname)
+                    raise FSError("DIR_EXISTS", dirname)
             else:
-                raise FSError("CANNOT_CREATE_DIR", "Can not create a directory, because path references a file: %(path)s", dirname)
+                raise FSError("NO_DIR", dirname, msg="Can not create a directory, because path references a file: %(path)s")
         
         if dir_item is None:
             parent_dir.contents[dirname] = self._make_dir_entry("dir", dirname)
@@ -236,51 +242,62 @@ class MemoryFS(FS):
     
     def _lock_dir(self, dirpath):
         
-        dir_entry = self._get_dir_entry(path)
+        dir_entry = self._get_dir_entry(dirpath)
         dir_entry.lock()
     
         
     def _unlock_dir(self, dirpath):
         
-        dir_entry = self._get_dir_entry(path)
+        dir_entry = self._get_dir_entry(dirpath)
         dir_entry.unlock()
     
-    def is_dir_locked(self, dirpath):
+    def _is_dir_locked(self, dirpath):
         
-        dir_entry = self._get_dir_entry(path)
+        dir_entry = self._get_dir_entry(dirpath)
         return dir_entry.islocked()
 
     
-    def open(self, path, mode, **kwargs):
-                
-        dir_entry = self._get_dir_entry(path)
-        if dir_entry is None:
-            dirpath, filename = pathsplit(path)
+    def open(self, path, mode="r", **kwargs):
+        
+        filepath, filename = pathsplit(path)        
+        dir_entry = self._get_dir_entry(path)                    
         parent_dir_entry = self._get_dir_entry(filepath)
         
+        if parent_dir_entry is None or not parent_dir_entry.isdir():
+            raise FSError("NO_FILE", path)
+        
         if 'r' in mode or 'a' in mode:
-            if filename not in parent_dir_entry:
-                raise FSError("FILE_DOES_NOT_EXIST", "Can not open file that does not exist: %(path)s", path)
+            if filename not in parent_dir_entry.contents:
+                raise FSError("NO_FILE", path)
             
-            parent_dir.lock()
-            file_dir_entry = parent_dir_entry[filename]
-            mem_file = MemoryFile(path, self, file_dir_entry.value, mode)
+            self._lock_dir(filepath)
+            file_dir_entry = parent_dir_entry.contents[filename]
+            mem_file = MemoryFile(path, self, file_dir_entry.data, mode)
             file_dir_entry.num_reading += 1
             return mem_file
         
-        else:
-            self._make_dir_entry("file", filename)
-        
-        
+        elif 'w' in mode:
+            
+            if filename not in parent_dir_entry.contents:        
+                file_dir_entry = self._make_dir_entry("file", filename)
+                parent_dir_entry.contents[filename] = file_dir_entry
+            else:
+                file_dir_entry = parent_dir_entry.contents[fielname]
+                
+            mem_file = MemoryFile(path, self, None, mode)
+            file_dir_entry.num_writing = 1            
+            return mem_file
+                
         if parent_dir_entry is None:
-            raise FSError("DOES_NOT_EXIST", "File does not exist", path)
+            raise FSError("NO_FILE", path)
+        
         
         
     def _on_close_memory_file(self, path, value):
                 
-        self._unlock_dir(path)
-        
-        dir_entry = self._get_dir_entry(path)
+        filepath, filename = pathsplit(path)
+        self._unlock_dir(filepath)
+        dir_entry = self._get_dir_entry(path)        
         dir_entry.data = value
         
         
@@ -302,6 +319,9 @@ if __name__ == "__main__":
     mem_fs.mkdir('test/test2', recursive=True)
     mem_fs.mkdir('test/A', recursive=True)
     mem_fs.mkdir('test/A/B', recursive=True)
+    
+    mem_fs.open("test/readme.txt", 'w').write("Hello, World!")
+    
     #print mem_fs.listdir('test')
     #print mem_fs.isdir("test/test2")
     #print mem_fs.root