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 shutil
   9 import config
  10
  11 X = os.path.sep
  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.join(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 = xmlw.parseFile(self.name + X + hash + X + 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 + X + hash + X
  55                 if not os.path.exists(pre):
  56                         os.makedirs(pre)
  57                 try:
  58                         f = open(pre + file + ".xml.new", "w")
  59                         f.write(text)
  60                         f.close()
  61                         shutil.move(pre + file + ".xml.new", pre + file + ".xml")
  62                 except IOError, e:
  63                         LogEvent(WARN, "", "IOError " + str(e))
  64                         raise
  65                 os.umask(prev_umask)
  66
  67         def files(self):
  68                 """ Returns a list containing the files in the current XDB database """
  69                 files = []
  70                 for dir in os.listdir(self.name):
  71                         if(os.path.isdir(self.name + X + dir)):
  72                                 files.extend(os.listdir(self.name + X + dir))
  73                 if self.mangle:
  74                         files = [unmangle(x)[:-4] for x in files]
  75                 else:
  76                         files = [x[:-4] for x in files]
  77
  78                 while files.count(''):
  79                         files.remove('')
  80
  81                 return files
  82
  83         def request(self, file, xdbns):
  84                 """ Requests a specific xdb namespace from the XDB 'file' """
  85                 try:
  86                         document = self.__getFile(file)
  87                         for child in document.elements():
  88                                 if(child.getAttribute("xdbns") == xdbns):
  89                                         return child
  90                 except:
  91                         return None
  92
  93         def set(self, file, xdbns, element):
  94                 """ Sets a specific xdb namespace in the XDB 'file' to element """
  95                 try:
  96                         element.attributes["xdbns"] = xdbns
  97                         document = None
  98                         try:
  99                                 document = self.__getFile(file)
 100                         except IOError:
 101                                 pass
 102                         if(not document):
 103                                 document = xmlw.Element((None, "xdb"))
 104
 105                         # Remove the existing node (if any)
 106                         for child in document.elements():
 107                                 if(child.getAttribute("xdbns") == xdbns):
 108                                         document.children.remove(child)
 109                         # Add the new one
 110                         document.addChild(element)
 111
 112                         self.__writeFile(file, document.toXml())
 113                 except IOError, e:
 114                         LogEvent(WARN, "", "IOError " + str(e))
 115                         raise
 116
 117         def remove(self, file):
 118                 """ Removes an XDB file """
 119                 file = self.name + X + file[0:2] + X + file + ".xml"
 120                 if(self.mangle):
 121                         file = mangle(file)
 122                 try:
 123                         os.remove(file)
 124                 except IOError, e:
 125                         LogEvent(WARN, "", "IOError " + str(e))
 126                         raise
 127
 128
 129