From 29e9b7ab39c0f1589814d451204a105067f490ea Mon Sep 17 00:00:00 2001
From: Giovanni Mascellani <mascellani@poisson.phc.unipi.it>
Date: Sun, 5 Jan 2014 16:07:03 +0100
Subject: [PATCH] Drop caches after having processed folders.

This enhances a lot memory consumption when you have many folders
to process.

Signed-off-by: Giovanni Mascellani <mascellani@poisson.phc.unipi.it>
---
 offlineimap/accounts.py                 | 4 ++++
 offlineimap/folder/Base.py              | 3 +++
 offlineimap/folder/IMAP.py              | 2 ++
 offlineimap/folder/LocalStatus.py       | 2 ++
 offlineimap/folder/LocalStatusSQLite.py | 3 +++
 offlineimap/folder/Maildir.py           | 3 +++
 offlineimap/folder/UIDMaps.py           | 3 +++
 7 files changed, 20 insertions(+)

diff --git a/offlineimap/accounts.py b/offlineimap/accounts.py
index 18a36fc..7adc3a4 100644
--- a/offlineimap/accounts.py
+++ b/offlineimap/accounts.py
@@ -491,3 +491,7 @@ def syncfolder(account, remotefolder, quick):
         ui.error(e, msg = "ERROR in syncfolder for %s folder %s: %s" % \
                 (account, remotefolder.getvisiblename(),
                  traceback.format_exc()))
+    finally:
+        for folder in ["statusfolder", "localfolder", "remotefolder"]:
+            if folder in locals():
+                locals()[folder].dropmessagelistcache()
diff --git a/offlineimap/folder/Base.py b/offlineimap/folder/Base.py
index 87e165c..7121231 100644
--- a/offlineimap/folder/Base.py
+++ b/offlineimap/folder/Base.py
@@ -247,6 +247,9 @@ class BaseFolder(object):
 
         raise NotImplementedError
 
+    def dropmessagelistcache(self):
+        raise NotImplementedException
+
     def getmessagelist(self):
         """Gets the current message list.
         You must call cachemessagelist() before calling this function!"""
diff --git a/offlineimap/folder/IMAP.py b/offlineimap/folder/IMAP.py
index 00afce0..c405431 100644
--- a/offlineimap/folder/IMAP.py
+++ b/offlineimap/folder/IMAP.py
@@ -250,6 +250,8 @@ class IMAPFolder(BaseFolder):
                 rtime = imaplibutil.Internaldate2epoch(messagestr)
                 self.messagelist[uid] = {'uid': uid, 'flags': flags, 'time': rtime}
 
+    def dropmessagelistcache(self):
+        self.messagelist = None
 
     # Interface from BaseFolder
     def getmessagelist(self):
diff --git a/offlineimap/folder/LocalStatus.py b/offlineimap/folder/LocalStatus.py
index ec34965..d3b6cf0 100644
--- a/offlineimap/folder/LocalStatus.py
+++ b/offlineimap/folder/LocalStatus.py
@@ -161,6 +161,8 @@ class LocalStatusFolder(BaseFolder):
         self.readstatus(file)
         file.close()
 
+    def dropmessagelistcache(self):
+        self.messagelist = None
 
     def save(self):
         """Save changed data to disk. For this backend it is the same as saveall."""
diff --git a/offlineimap/folder/LocalStatusSQLite.py b/offlineimap/folder/LocalStatusSQLite.py
index 1b2adb0..9d7e559 100644
--- a/offlineimap/folder/LocalStatusSQLite.py
+++ b/offlineimap/folder/LocalStatusSQLite.py
@@ -203,6 +203,9 @@ class LocalStatusSQLiteFolder(BaseFolder):
             self.messagelist[uid]['labels'] = labels
             self.messagelist[uid]['mtime'] = row[2]
 
+    def dropmessagelistcache(self):
+        self.messagelist = None
+
     # Interface from LocalStatusFolder
     def save(self):
         pass
diff --git a/offlineimap/folder/Maildir.py b/offlineimap/folder/Maildir.py
index af1e5ff..3a19cc3 100644
--- a/offlineimap/folder/Maildir.py
+++ b/offlineimap/folder/Maildir.py
@@ -220,6 +220,9 @@ class MaildirFolder(BaseFolder):
         if self.messagelist is None:
             self.messagelist = self._scanfolder()
 
+    def dropmessagelistcache(self):
+        self.messagelist = None
+
     # Interface from BaseFolder
     def getmessagelist(self):
         return self.messagelist
diff --git a/offlineimap/folder/UIDMaps.py b/offlineimap/folder/UIDMaps.py
index e1a6f5f..eb4fbae 100644
--- a/offlineimap/folder/UIDMaps.py
+++ b/offlineimap/folder/UIDMaps.py
@@ -125,6 +125,9 @@ class MappedIMAPFolder(IMAPFolder):
         finally:
             self.maplock.release()
 
+    def dropmessagelistcache(self):
+        self._mb.dropmessagelistcache()
+
     # Interface from BaseFolder
     def uidexists(self, ruid):
         """Checks if the (remote) UID exists in this Folder"""