code.delx.au - pymsnt/blob - src/xdb.py

   1 # Copyright 2004-2005 James Bunton <james@delx.cjb.net>
   2 # Licensed for distribution under the GPL version 2, check COPYING for details
   3
   4 from tlib import xmlw
   5 from debug import LogEvent, INFO, WARN
   6 import os
   7 import os.path
   8 import config
   9 import legacy
  10
  11 SPOOL_UMASK = 0077
  12
  13
  14 def unmangle(file):
  15         chunks = file.split("%")
  16         end = chunks.pop()
  17         file = "%s@%s" % ("%".join(chunks), end)
  18         return file
  19
  20 def mangle(jid):
  21         return jid.replace("@", "%")
  22
  23
  24 class XDB:
  25         """
  26         Class for storage of data.
  27
  28         Create one instance of the class for each XDB 'folder' you want.
  29         Call request()/set() with the xdbns argument you wish to retrieve
  30         """
  31         def __init__(self, name, mangle=False):
  32                 """ Creates an XDB object. If mangle is True then any '@' signs in filenames will be changed to '%' """
  33                 self.name = os.path.abspath(config.spooldir) + '/' + name
  34                 if not os.path.exists(self.name):
  35                         os.makedirs(self.name)
  36                 self.mangle = mangle
  37
  38         def __getFile(self, file):
  39                 if(self.mangle):
  40                         file = mangle(file)
  41
  42                 hash = file[0:2]
  43                 document = xmlw.parseFile(self.name + "/" + hash + "/" + file + ".xml")
  44
  45                 return document
  46
  47         def __writeFile(self, file, text):
  48                 if(self.mangle):
  49                         file = mangle(file)
  50
  51                 prev_umask = os.umask(SPOOL_UMASK)
  52                 hash = file[0:2]
  53                 pre = self.name + "/" + hash + "/"
  54                 if not os.path.exists(pre):
  55                         os.makedirs(pre)
  56                 f = open(pre + file + ".xml", "w")
  57                 f.write(text)
  58                 f.close()
  59                 os.umask(prev_umask)
  60
  61         def files(self):
  62                 """ Returns a list containing the files in the current XDB database """
  63                 files = []
  64                 for dir in os.listdir(self.name):
  65                         if(os.path.isdir(self.name + "/" + dir)):
  66                                 files.extend(os.listdir(self.name + "/" + dir))
  67                 if self.mangle:
  68                         files = [unmangle(x)[:-4] for x in files]
  69                 else:
  70                         files = [x[:-4] for x in files]
  71
  72                 while files.count(''):
  73                         files.remove('')
  74
  75                 return files
  76
  77         def request(self, file, xdbns):
  78                 """ Requests a specific xdb namespace from the XDB 'file' """
  79                 try:
  80                         document = self.__getFile(file)
  81                         for child in document.elements():
  82                                 if(child.getAttribute("xdbns") == xdbns):
  83                                         return child
  84                 except:
  85                         return None
  86
  87         def set(self, file, xdbns, element):
  88                 """ Sets a specific xdb namespace in the XDB 'file' to element """
  89                 try:
  90                         element.attributes["xdbns"] = xdbns
  91                         document = None
  92                         try:
  93                                 document = self.__getFile(file)
  94                         except IOError:
  95                                 pass
  96                         if(not document):
  97                                 document = xmlw.Element((None, "xdb"))
  98
  99                         # Remove the existing node (if any)
 100                         for child in document.elements():
 101                                 if(child.getAttribute("xdbns") == xdbns):
 102                                         document.children.remove(child)
 103                         # Add the new one
 104                         document.addChild(element)
 105
 106                         self.__writeFile(file, document.toXml())
 107                 except IOError, e:
 108                         LogEvent(WARN, "", "IOError " + str(e))
 109                         raise
 110
 111         def remove(self, file):
 112                 """ Removes an XDB file """
 113                 file = self.name + "/" + file[0:2] + "/" + file + ".xml"
 114                 if(self.mangle):
 115                         file = mangle(file)
 116                 try:
 117                         os.remove(file)
 118                 except IOError, e:
 119                         LogEvent(WARN, "", "IOError " + str(e))
 120                         raise
 121
 122
 123