diff options
Diffstat (limited to 'Nitrate.py')
| -rw-r--r-- | Nitrate.py | 46 |
1 files changed, 44 insertions, 2 deletions
@@ -47,6 +47,43 @@ setLogLevel() # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +# Caching +# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +def setCacheLevel(level=None): + """ + Set the caching level. + + If the level parameter is not specified environment variable CACHE + is inspected instead. There are three levels available: + + 0 ... Write any changes to objects immediately to the server + 1 ... Changes pushed only by update() or upon destruction + 2 ... Any loaded object is saved for possible future use + 3 ... Where possible, pre-fetch all available values + + By default cache level 2 is used. That is any changes to objects are + pushed to the server only upon destruction or when explicitly + requested with the update() method. Also, any object already loaded + from the server is kept in local cache so that future references to + that object are faster. + """ + + global _cache + if level is None: + try: + _cache = int(os.environ["CACHE"]) + except StandardError: + _cache = 2 + elif level >= 0 and level <= 3: + _cache = level + else: + raise NitrateError("Invalid cache level '{0}'".format(level)) + +setCacheLevel() + + +# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # Default Getter & Setter # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -80,12 +117,17 @@ def _setter(field): # Initialize the attribute unless already done if getattr(self, "_" + field) is NitrateNone: self._get() - # Update only if changed, remember modified state + # Update only if changed if getattr(self, "_" + field) != value: setattr(self, "_" + field, value) - self._modified = True log.info("Updating {0}'s {1} to '{2}'".format( self.identifier, field, value)) + # Remember modified state if caching + if _cache: + self._modified = True + # Save the changes immediately otherwise + else: + self._update() return setter |