Give some love to UIDMaps

- Some documentation improvements, this is a severely underdocumented
  class. This still needs some further improvements though.

- Don't use apply(Baseclass) (which is going away in Python 3), use
  IMAPFolder.__init__(self, *args, **kwargs).

- Don't call ValueError, string. It is ValueError(string)

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>
This commit is contained in:
Sebastian Spaeth 2011-03-16 16:24:07 +01:00 committed by Nicolas Sebrecht
parent 933d7c4eed
commit dc3ad723c9
2 changed files with 32 additions and 21 deletions

View File

@ -158,20 +158,21 @@ class BaseFolder:
def savemessage(self, uid, content, flags, rtime):
"""Writes a new message, with the specified uid.
If the uid is < 0, the backend should assign a new uid and return it.
If the backend cannot assign a new uid, it returns the uid passed in
WITHOUT saving the message.
If the uid is < 0: The backend should assign a new uid and
return it. In case it cannot assign a new uid, it returns
the negative uid passed in WITHOUT saving the message.
If the backend CAN assign a new uid, but cannot find out what this UID
is (as is the case with many IMAP servers), it returns 0 but DOES save
the message.
If the backend CAN assign a new uid, but cannot find out what
this UID is (as is the case with some IMAP servers), it
returns 0 but DOES save the message.
IMAP backend should be the only one that can assign a new uid.
IMAP backend should be the only one that can assign a new
uid.
If the uid is > 0, the backend should set the uid to this, if it can.
If it cannot set the uid to that, it will save it anyway.
It will return the uid assigned in any case.
If it cannot set the uid to that, it will save it anyway.
It will return the uid assigned in any case.
"""
raise NotImplementedException

View File

@ -23,6 +23,14 @@ from IMAP import IMAPFolder
import os.path, re
class MappingFolderMixIn:
"""Helper class to map between Folder() instances where both side assign a uid
Instance variables (self.):
r2l: dict mapping message uids: self.r2l[remoteuid]=localuid
l2r: dict mapping message uids: self.r2l[localuid]=remoteuid
#TODO: what is the difference, how are they used?
diskr2l: dict mapping message uids: self.r2l[remoteuid]=localuid
diskl2r: dict mapping message uids: self.r2l[localuid]=remoteuid"""
def _initmapping(self):
self.maplock = Lock()
(self.diskr2l, self.diskl2r) = self._loadmaps()
@ -131,30 +139,32 @@ class MappingFolderMixIn:
def savemessage(self, uid, content, flags, rtime):
"""Writes a new message, with the specified uid.
If the uid is < 0, the backend should assign a new uid and return it.
If the backend cannot assign a new uid, it returns the uid passed in
WITHOUT saving the message.
If the backend CAN assign a new uid, but cannot find out what this UID
is (as is the case with many IMAP servers), it returns 0 but DOES save
the message.
IMAP backend should be the only one that can assign a new uid.
The UIDMaps class will not return a newly assigned uid, as it
internally maps different uids between IMAP servers. So a
successful savemessage() invocation will return the same uid it
has been invoked with. As it maps between 2 IMAP servers which
means the source message must already have an uid, it requires a
positive uid to be passed in. Passing in a message with a
negative uid will do nothing and return the negative uid.
If the uid is > 0, the backend should set the uid to this, if it can.
If it cannot set the uid to that, it will save it anyway.
It will return the uid assigned in any case.
"""
# Mapped UID instances require the source to already have a
# positive UID, so simply return here.
if uid < 0:
# We cannot assign a new uid.
return uid
#if msg uid already exists, just modify the flags
if uid in self.r2l:
self.savemessageflags(uid, flags)
return uid
newluid = self._mb.savemessage(self, -1, content, flags, rtime)
if newluid < 1:
raise ValueError, "Backend could not find uid for message"
raise ValueError("Backend could not find uid for message")
self.maplock.acquire()
try:
self.diskl2r[newluid] = uid
@ -221,5 +231,5 @@ class MappingFolderMixIn:
# Define a class for local part of IMAP.
class MappedIMAPFolder(MappingFolderMixIn, IMAPFolder):
def __init__(self, *args, **kwargs):
apply(IMAPFolder.__init__, (self,) + args, kwargs)
IMAPFolder.__init__(self, *args, **kwargs)
self._initmapping()