(Logical change 1.10)

git-svn-id: https://svn.mcs.anl.gov/repos/bcfg/trunk/bcfg2@38 ce84e21b-d406-0410-9b95-82705330c041

1 files changed, 56 insertions, 0 deletions

diff --git a/src/GeneratorUtils.py b/src/GeneratorUtils.py
index e69de29bb..69fe86e3f 100644
--- a/src/GeneratorUtils.py
+++ b/src/GeneratorUtils.py
@@ -0,0 +1,56 @@
+#!/usr/bin/env python
+# $Id$
+
+from os import listdir, stat
+from stat import ST_MTIME
+
+class FileBacked(object):
+    '''FileBacked is a class that will cache file data and automatically reload it as required from disk.
+    This class is currently READ-ONLY.'''
+
+    def __init__(self,filename):
+        '''Setup initial structures'''
+        self.filename = filename
+        self.mtime = stat(filename)[ST_MTIME]
+        self._data = file(filename).read()
+
+    def getdata(self):
+        mtime = stat(self.filename)[ST_MTIME]
+        if mtime != self.mtime:
+            self._data = file(self.filename).read()
+            self.mtime = mtime
+        return self._data
+
+    def setdata(self,val):
+        pass
+
+    data=property(getdata,setdata)
+
+class DirectoryBacked(object):
+    '''DirectoryBacked caches a complete directory (including proper negative caching)'''
+
+    def __init__(self,path):
+        self.path = path
+        self._entries = {}
+        self.mtime = stat(path)[ST_MTIME]
+        for entry in listdir(path):
+            self._entries[entry] = FileBacked("%s/%s"%(path,entry))
+
+    def GetEntries(self):
+        mtime = stat(self.path)[ST_MTIME]
+        if mtime != self.mtime:
+            current = self._entries.keys()
+            new = listdir(self.path)
+            for key in new:
+                if key not in current:
+                    self._entries[key] = FileBacked("%s/%s"%(self.path,key))
+            for key in current:
+                if key not in new:
+                    del self._entries[key]
+        return self._entries
+
+    def SetEntries(self,val):
+        pass
+
+    entries = property(GetEntries,SetEntries)
+