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added locking around thing._commit()

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This commit is contained in:
spez
2009-07-30 15:14:22 -07:00
parent ec2d9f1863
commit d6c06371b1
1 changed files with 106 additions and 32 deletions
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138
r2/r2/lib/db/thing.py
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@@ -105,7 +105,7 @@ class DataThing(object):
self._t[attr] = val
if make_dirty and val != old_val:
self._dirties[attr] = val
self._dirties[attr] = (old_val, val)
def __getattr__(self, attr):
#makes pickling work for some reason
@@ -127,17 +127,55 @@ class DataThing(object):
raise AttributeError,\
attr + ' not found. thing is not loaded'
def _cache_key(self):
return thing_prefix(self.__class__.__name__, self._id)
def _other_self(self):
"""Load from the cached version of myself. Skip the local cache."""
return cache.get(self._cache_key(), local = False)
def _cache_myself(self):
cache.set(self._cache_key(), self)
def _sync_latest(self):
"""Load myself from the cache to and re-apply the .dirties
list to make sure we don't overwrite a previous commit. """
other_self = self._other_self()
if not other_self:
return self._dirty
g.log.info("thing conflict: " + self._fullname)
#copy in the cache's version
for prop in self._base_props:
self.__setattr__(prop, getattr(other_self, prop), False)
self._t = other_self._t
#re-apply the .dirties
old_dirties = self._dirties
self._dirties = {}
for k, (old_val, new_val) in old_dirties.iteritems():
setattr(self, k, new_val)
#return whether we're still dirty or not
return self._dirty
def _commit(self, keys=None):
if not self._created:
self._create()
if self._dirty:
with g.make_lock('commit_' + self._fullname):
if not self._sync_latest():
#sync'd and we have nothing to do now, but we still cache anyway
self._cache_myself()
return
if keys:
keys = tup(keys)
to_set = dict((k, self._dirties[k])
to_set = dict((k, self._dirties[k][1])
for k in keys if self._dirties.has_key(k))
else:
to_set = self._dirties
to_set = dict((k, v[1]) for k, v in self._dirties.iteritems())
data_props = {}
thing_props = {}
@@ -149,10 +187,10 @@ class DataThing(object):
if data_props:
self._set_data(self._type_id, self._id, **data_props)
if thing_props:
self._set_props(self._type_id, self._id, **thing_props)
if keys:
for k in keys:
if self._dirties.has_key(k):
@@ -160,8 +198,30 @@ class DataThing(object):
else:
self._dirties.clear()
# always set the cache
cache.set(thing_prefix(self.__class__.__name__, self._id), self)
self._cache_myself()
@classmethod
def _all_data_int_props(cls, items):
"""Returns the cache keys for _data_int_props plus keys for
any properties that end with _int_prop_suffix."""
int_props = {}
#prop prefix
def pp(prop, id):
return prop + '_' + str(i._id)
#do defined data props first, this also checks default values
for prop in cls._data_int_props:
for i in items:
int_props[pp(prop, i._id)] = getattr(i, prop)
#int props based on the suffix
for i in items:
for prop, val in i._t.iteritems():
if cls._int_prop_suffix and prop.endswith(cls._int_prop_suffix):
int_props[pp(prop, i._id)] = val
return int_props
@classmethod
def _load_multi(cls, need):
@@ -179,24 +239,10 @@ class DataThing(object):
#avoid race condition when incrementing data int props by
#putting all the int props into the cache.
to_save.update(cls._all_data_int_props(need))
#prop prefix
def pp(prop, id):
return prop + '_' + str(i._id)
#do defined data props first, this also checks default values
for prop in cls._data_int_props:
for i in need:
to_save[pp(prop, i._id)] = getattr(i, prop)
#int props based on the suffix
for i in need:
for prop, val in i._t.iteritems():
if cls._int_prop_suffix and prop.endswith(cls._int_prop_suffix):
to_save[pp(prop, i._id)] = val
#write the data to the cache
cache.set_multi(to_save, prefix)
def _load(self):
self._load_multi(self)
@@ -206,10 +252,19 @@ class DataThing(object):
self._load()
def _incr(self, prop, amt = 1):
if self._dirty:
raise ValueError, "cannot incr dirty thing"
#make sure we're incr'ing an _int_prop or _data_int_prop.
if prop not in self._int_props:
if (prop in self._data_int_props or
self._int_prop_suffix and prop.endswith(self._int_prop_suffix)):
#if we're incr'ing a data_prop, make sure we're loaded
if not self._loaded:
self._load()
else:
raise ValueError, "cannot incr non int prop"
prefix = thing_prefix(self.__class__.__name__)
key = prefix + prop + '_' + str(self._id)
cache_val = old_val = cache.get(key)
@@ -228,13 +283,11 @@ class DataThing(object):
tdb.incr_thing_prop(self._type_id, self._id, prop[1:], amt)
else:
self._incr_data(self._type_id, self._id, prop, amt)
cache.set(prefix + str(self._id), self)
#cache
if cache_val:
cache.incr(key, amt)
else:
cache.set(key, getattr(self, prop))
#update cache
if cache_val is None:
cache.add(key, old_val)
cache.incr(key, amt)
@property
def _id36(self):
@@ -260,6 +313,8 @@ class DataThing(object):
for prop in cls._int_props:
keys = dict((i, getattr(item, prop))
for i, item in items.iteritems())
#this is a 'set' because the db values are gospel
cache.set_multi(keys, prefix + prop + '_' )
return items
@@ -276,6 +331,25 @@ class DataThing(object):
if need:
cls._load_multi(need)
###load the int_props
keys = []
#keys for the _int_props
for prop in cls._int_props:
for _id in ids:
keys.append(prop + '_' + str(_id))
#add in the _data_int_props if there are any
keys.extend(cls._all_data_int_props(bases.values()).keys())
int_vals = cache.get_multi(keys, prefix)
for key, val in int_vals.iteritems():
#for each int prop in the cache, set it on the object. the
#response from the cache looks like: _ups_177, so we need
#to split it
i = key.rfind('_')
prop, _id = key[:i], int(key[i+1:])
bases[_id].__setattr__(prop, int_vals[key], False)
#e.g. add the sort prop
if extra_props:
for _id, props in extra_props.iteritems():