[Zope-CVS] CVS: Products/FileCacheManager - FileCacheManager.py:1.8

[Jens Vagelpohl]

Update of /cvs-repository/Products/FileCacheManager
In directory cvs.zope.org:/tmp/cvs-serv3948

Modified Files:
	FileCacheManager.py 
Log Message:
- couple docstring changes
- less stupid check for writability of a chosen cache directory
- some variable name changes
- some added whitespace


=== Products/FileCacheManager/FileCacheManager.py 1.7 => 1.8 ===
--- Products/FileCacheManager/FileCacheManager.py:1.7	Fri Aug 13 08:53:50 2004
+++ Products/FileCacheManager/FileCacheManager.py	Fri Aug 13 12:58:29 2004
@@ -34,10 +34,10 @@
 caches = {}
 
 class FileCache(RAMCache):
-    """A cache that caches to the filesystem """
+    """ A cache that caches rendered content to the filesystem """
 
     def __init__(self, path='/tmp'):
-        # cache maps physical paths to files.
+        # self.cache maps physical ZODB paths to disk files.
         self.cache=OOBTree.OOBTree()
         self.writelock = allocate_lock()
         self.next_cleanup = 0
@@ -49,8 +49,9 @@
         human-readable path, but otherwise makes life much easier """
         phys_path = '/'.join(ob.getPhysicalPath())[1:]
         hashed = md5.new(phys_path).hexdigest()
-        fn = os.path.join(self._dir, hashed[:2], hashed)
-        return fn
+        fname = os.path.join(self._dir, hashed[:2], hashed)
+
+        return fname
 
     def getDir(self):
         """ Retrieve the filesystem directory used for caching """
@@ -62,21 +63,27 @@
         self._makeDirs()
 
     def ZCache_invalidate(self, ob):
-        """ Invalidates cache entries that apply to ob, from FSCacheManager """
+        """ Invalidates cache entries that apply to ob """
         # XXX ADD LOCKS HERE
-        fn = self._fileName(ob)
+        fname = self._fileName(ob)
+
         try:
-            if os.path.exists(fn): # XXX race?
-                os.remove(fn)
+            if os.path.exists(fname): # XXX race?
+                os.remove(fname)
         except IOError, msg:
-             LOG('DiskCacheManger', ERROR, 'IOError removing file', error=msg)
+             zLOG.LOG( 'FileCacheManager'
+                     , zLOG.ERROR
+                     , 'IOError removing file'
+                     , error=msg
+                     )
 
     def ZCache_get(self, ob, view_name='', keywords=None,
                    mtime_func=None, default=None):
-        """ Gets a cache entry """
-        f_path = self._fileName(ob)
+        """ Gets a cache entry and return a filestream_iterator """
+        fname = self._fileName(ob)
+
         try:
-            f = filestream_iterator(f_path, 'rb')
+            fiter = filestream_iterator(fname, 'rb')
         except IOError:
             # couldn't get the actual cache
             zLOG.LOG('FileCacheManager', zLOG.INFO,
@@ -84,22 +91,23 @@
                      '/'.join(ob.getPhysicalPath())
                      )
             return default
-        return f
+
+        return fiter
 
     def ZCache_set(self, ob, data=None, view_name='', keywords=None,
                    mtime_func=None):
-        """ Sets a cache entry. Code swiped from FSCacheManager. """
+        """ Sets a cache entry. """
         # XXX locks?
-        fnId = self._fileName(ob)
+        fname = self._fileName(ob)
 
         if data is None:
             # maybe it's a File or an Image, grab the data
             data = ob.data
 
         try:
-            if fnId:
+            if fname:
                 # use a temp. file for writing.
-                fd, tempname = tempfile.mkstemp() #open(fnId, 'wb')
+                fd, tempname = tempfile.mkstemp()
                 # isinstance won't work on extension class
                 if type(data) == type(''):
                     os.write(fd, data)
@@ -111,24 +119,26 @@
                     while data is not None and hasattr(data, 'next'):
                         os.write(fd, data.data)
                         data = data.next
+
                 os.fsync(fd)
                 os.close(fd)
                 # rename that sucker.
                 # This may fail if they are not on the same filesystem.
                 try:
-                    os.rename(tempname, fnId)
+                    os.rename(tempname, fname)
                 except OSError:
-                    # windows fails if fnId exists.
+                    # windows fails if fname exists.
                     # if this doesn't work, tough noogies
-                    os.unlink(fnId)
-                    os.rename(tempname, fnId)
+                    os.unlink(fname)
+                    os.rename(tempname, fname)
 
         except IOError, msg:
-            LOG('DiskCacheManger', ERROR, 'IOError writing file', error=msg)
+            LOG('FileCacheManager', ERROR, 'IOError writing file', error=msg)
 
     def _makeDirs(self):
         """ Make sure we have somewhere to put files. """
         chars = '0123456789abcdef'
+
         for char in chars:
             for char2 in chars:
                 dirpath = os.path.join(self._dir, '%s%s' % (char, char2))
@@ -202,14 +212,11 @@
 
 def manage_addFileCacheManager(self, id, path='/tmp', title='', REQUEST=None):
     """ Adds a FileCacheManager to the folder. """
-    test_path = os.path.join(path, 'test.txt')
-    try:
-        fd = open(test_path, 'w')
+    # Test to see that we can write into the place we got as the cache dir
+    if os.access(path, os.W_OK):
         self._setObject(id, FileCacheManager(id, path, title))
         msg = 'FileCacheManager created.'
-        fd.close()
-        os.unlink(test_path)
-    except IOError:
+    else:
         msg = 'Invalid directory path "%s"' % path
         if REQUEST is None:
             raise(IOError, msg)