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 import utils
   5 if(utils.checkTwisted()):
   6         from twisted.xish.domish import Element
   7 else:
   8         from tlib.domish import Element
   9 from debug import LogEvent, INFO, WARN
  10 import os
  11 import os.path
  12 import config
  13 import legacy
  14
  15 SPOOL_UMASK = 0077
  16
  17
  18 def unmangle(file):
  19         chunks = file.split("%")
  20         end = chunks.pop()
  21         file = "%s@%s" % ("%".join(chunks), end)
  22         return file
  23
  24 def mangle(jid):
  25         return jid.replace("@", "%")
  26
  27
  28 class XDB:
  29         """
  30         Class for storage of data.
  31
  32         Create one instance of the class for each XDB 'folder' you want.
  33         Call request()/set() with the xdbns argument you wish to retrieve
  34         """
  35         def __init__(self, name, mangle=False):
  36                 """ Creates an XDB object. If mangle is True then any '@' signs in filenames will be changed to '%' """
  37                 self.name = os.path.abspath(config.spooldir) + '/' + name
  38                 if not os.path.exists(self.name):
  39                         os.makedirs(self.name)
  40                 self.mangle = mangle
  41
  42         def __getFile(self, file):
  43                 if(self.mangle):
  44                         file = mangle(file)
  45
  46                 hash = file[0:2]
  47                 document = utils.parseFile(self.name + "/" + hash + "/" + file + ".xml")
  48
  49                 return document
  50
  51         def __writeFile(self, file, text):
  52                 if(self.mangle):
  53                         file = mangle(file)
  54
  55                 prev_umask = os.umask(SPOOL_UMASK)
  56                 hash = file[0:2]
  57                 pre = self.name + "/" + hash + "/"
  58                 if not os.path.exists(pre):
  59                         os.makedirs(pre)
  60                 f = open(pre + file + ".xml", "w")
  61                 f.write(text)
  62                 f.close()
  63                 os.umask(prev_umask)
  64
  65         def files(self):
  66                 """ Returns a list containing the files in the current XDB database """
  67                 files = []
  68                 for dir in os.listdir(self.name):
  69                         if(os.path.isdir(self.name + "/" + dir)):
  70                                 files.extend(os.listdir(self.name + "/" + dir))
  71                 if self.mangle:
  72                         files = [unmangle(x)[:-4] for x in files]
  73                 else:
  74                         files = [x[:-4] for x in files]
  75
  76                 while files.count(''):
  77                         files.remove('')
  78
  79                 return files
  80
  81         def request(self, file, xdbns):
  82                 """ Requests a specific xdb namespace from the XDB 'file' """
  83                 try:
  84                         document = self.__getFile(file)
  85                         for child in document.elements():
  86                                 if(child.getAttribute("xdbns") == xdbns):
  87                                         return child
  88                 except:
  89                         return None
  90
  91         def set(self, file, xdbns, element):
  92                 """ Sets a specific xdb namespace in the XDB 'file' to element """
  93                 try:
  94                         element.attributes["xdbns"] = xdbns
  95                         document = None
  96                         try:
  97                                 document = self.__getFile(file)
  98                         except IOError:
  99                                 pass
 100                         if(not document):
 101                                 document = Element((None, "xdb"))
 102
 103                         # Remove the existing node (if any)
 104                         for child in document.elements():
 105                                 if(child.getAttribute("xdbns") == xdbns):
 106                                         document.children.remove(child)
 107                         # Add the new one
 108                         document.addChild(element)
 109
 110                         self.__writeFile(file, document.toXml())
 111                 except IOError, e:
 112                         LogEvent(WARN, "", "IOError " + str(e))
 113                         raise
 114
 115         def remove(self, file):
 116                 """ Removes an XDB file """
 117                 file = self.name + "/" + file[0:2] + "/" + file + ".xml"
 118                 if(self.mangle):
 119                         file = mangle(file)
 120                 try:
 121                         os.remove(file)
 122                 except IOError, e:
 123                         LogEvent(WARN, "", "IOError " + str(e))
 124                         raise
 125
 126
 127