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