Implementing caches for a session

[gc-dialer] / src / session.py

diff --git a/src/session.py b/src/session.py
index 17c32b5..ae98cdd 100644 (file)
--- a/src/session.py
+++ b/src/session.py
@@ -2,11 +2,19 @@ import os
 import time
 import logging
 
+try:
+       import cPickle
+       pickle = cPickle
+except ImportError:
+       import pickle
+
 from PyQt4 import QtCore
 
 from util import qore_utils
 from util import concurrent
+from util import misc as misc_utils
 
+import constants
 from backends import gv_backend
 
 
@@ -144,6 +152,8 @@ class Session(QtCore.QObject):
        LOGGINGIN_STATE = "logging in"
        LOGGEDIN_STATE = "logged in"
 
+       _OLDEST_COMPATIBLE_FORMAT_VERSION = misc_utils.parse_version("1.2.0")
+
        _LOGGEDOUT_TIME = -1
        _LOGGINGIN_TIME = 0
 
@@ -209,21 +219,27 @@ class Session(QtCore.QObject):
                self._loggedInTime = self._LOGGEDOUT_TIME
                self.clear()
 
-       def update_contacts(self):
+       def update_contacts(self, force = True):
+               if not force and self._contacts:
+                       return
                le = concurrent.AsyncLinearExecution(self._pool, self._update_contacts)
                self._perform_op_while_loggedin(le)
 
        def get_contacts(self):
                return self._contacts
 
-       def update_messages(self):
+       def update_messages(self, force = True):
+               if not force and self._messages:
+                       return
                le = concurrent.AsyncLinearExecution(self._pool, self._update_messages)
                self._perform_op_while_loggedin(le)
 
        def get_messages(self):
                return self._messages
 
-       def update_history(self):
+       def update_history(self, force = True):
+               if not force and self._history:
+                       return
                le = concurrent.AsyncLinearExecution(self._pool, self._update_history)
                self._perform_op_while_loggedin(le)
 
@@ -319,8 +335,13 @@ class Session(QtCore.QObject):
                                finalState = self.LOGGEDIN_STATE
                                self.loggedIn.emit()
                                if oldUsername != self._username:
-                                       self._load_from_cache()
-                               loginOps = self._loginOps[:]
+                                       needOps = not self._load()
+                               else:
+                                       needOps = True
+                               if needOps:
+                                       loginOps = self._loginOps[:]
+                               else:
+                                       loginOps = []
                                del self._loginOps[:]
                                for asyncOp in loginOps:
                                        asyncOp.start()
@@ -329,7 +350,7 @@ class Session(QtCore.QObject):
                finally:
                        self.stateChange.emit(finalState)
 
-       def _load_from_cache(self):
+       def _load(self):
                updateContacts = len(self._contacts) != 0
                updateMessages = len(self._messages) != 0
                updateHistory = len(self._history) != 0
@@ -342,6 +363,12 @@ class Session(QtCore.QObject):
                self._dnd = False
                self._callback = ""
 
+               loadedFromCache = self._load_from_cache()
+               if loadedFromCache:
+                       updateContacts = True
+                       updateMessages = True
+                       updateHistory = True
+
                if updateContacts:
                        self.contactsUpdated.emit()
                if updateMessages:
@@ -353,9 +380,63 @@ class Session(QtCore.QObject):
                if oldCallback != self._callback:
                        self.callbackNumberChanged.emit(self._callback)
 
+               return loadedFromCache
+
+       def _load_from_cache(self):
+               if self._cachePath is None:
+                       return False
+               cachePath = os.path.join(self._cachePath, "%s.cache" % self._username)
+
+               try:
+                       with open(cachePath, "rb") as f:
+                               dumpedData = pickle.load(f)
+               except (pickle.PickleError, IOError, EOFError, ValueError):
+                       _moduleLogger.exception("Pickle fun loading")
+                       return False
+               except:
+                       _moduleLogger.exception("Weirdness loading")
+                       return False
+
+               (
+                       version, build,
+                       contacts, messages, history, dnd, callback
+               ) = dumpedData
+
+               if misc_utils.compare_versions(
+                       self._OLDEST_COMPATIBLE_FORMAT_VERSION,
+                       misc_utils.parse_version(version),
+               ) <= 0:
+                       _moduleLogger.info("Loaded cache")
+                       self._contacts = contacts
+                       self._messages = messages
+                       self._history = history
+                       self._dnd = dnd
+                       self._callback = callback
+                       return True
+               else:
+                       _moduleLogger.debug(
+                               "Skipping cache due to version mismatch (%s-%s)" % (
+                                       version, build
+                               )
+                       )
+                       return False
+
        def _save_to_cache(self):
-               # @todo
-               pass
+               _moduleLogger.info("Saving cache")
+               if self._cachePath is None:
+                       return
+               cachePath = os.path.join(self._cachePath, "%s.cache" % self._username)
+
+               try:
+                       dataToDump = (
+                               constants.__version__, constants.__build__,
+                               self._contacts, self._messages, self._history, self._dnd, self._callback
+                       )
+                       with open(cachePath, "wb") as f:
+                               pickle.dump(dataToDump, f, pickle.HIGHEST_PROTOCOL)
+                       _moduleLogger.info("Cache saved")
+               except (pickle.PickleError, IOError):
+                       _moduleLogger.exception("While saving")
 
        def _clear_cache(self):
                updateContacts = len(self._contacts) != 0