mirror of
https://github.com/reddit-archive/reddit.git
synced 2026-01-24 22:38:09 -05:00
tdb_cassandra: Remove obviated Relation infrastructure.
This has been replaced with DenormalizedRelation which: * uses an order of magnitude less storage space. * has shown, on average, 50% better response times. * does single-row lookups rather than large multigets.
This commit is contained in:
Neil Williams
@@ -215,7 +215,7 @@ class Counter(object):
|
||||
|
||||
|
||||
class ThingBase(object):
|
||||
# base class for Thing and Relation
|
||||
# base class for Thing
|
||||
|
||||
__metaclass__ = ThingMeta
|
||||
|
||||
@@ -541,8 +541,6 @@ class ThingBase(object):
|
||||
def _from_columns(cls, t_id, columns):
|
||||
"""Given a dictionary of freshly deserialized columns
|
||||
construct an instance of cls"""
|
||||
# if modifying this, check Relation._from_columns and see if
|
||||
# you should change it as well
|
||||
t = cls()
|
||||
t._orig = columns
|
||||
t._id = t_id
|
||||
@@ -817,144 +815,6 @@ class UuidThing(ThingBase):
|
||||
def _cache_key_id(cls, t_id):
|
||||
return cls._cache_prefix() + str(t_id)
|
||||
|
||||
class Relation(ThingBase):
|
||||
_timestamp_prop = 'date'
|
||||
|
||||
def __init__(self, thing1_id, thing2_id, **kw):
|
||||
# NB! When storing relations between postgres-backed Thing
|
||||
# objects, these IDs are actually ID36s
|
||||
ThingBase.__init__(self,
|
||||
_id = self._rowkey(thing1_id, thing2_id),
|
||||
**kw)
|
||||
self._orig['thing1_id'] = thing1_id
|
||||
self._orig['thing2_id'] = thing2_id
|
||||
|
||||
@will_write
|
||||
def _destroy(self, write_consistency_level = None):
|
||||
# only implemented on relations right now, but at present
|
||||
# there's no technical reason for this
|
||||
self._cf.remove(self._id,
|
||||
write_consistency_level = self._wcl(write_consistency_level))
|
||||
self._on_destroy()
|
||||
thing_cache.delete(self._cache_key())
|
||||
|
||||
def _on_destroy(self):
|
||||
"""Called *after* the destruction of the Thing on the
|
||||
destroyed Thing's mortal shell"""
|
||||
# only implemented on relations right now, but at present
|
||||
# there's no technical reason for this
|
||||
pass
|
||||
|
||||
@classmethod
|
||||
def _fast_query(cls, thing1s, thing2s, properties = None, **kw):
|
||||
"""Find all of the relations of this class between all of the
|
||||
members of thing1_ids and thing2_ids"""
|
||||
thing1s, thing1s_is_single = tup(thing1s, True)
|
||||
thing2s, thing2s_is_single = tup(thing2s, True)
|
||||
|
||||
if not thing1s or not thing2s:
|
||||
return {}
|
||||
|
||||
# grab the last time each thing1 modified this relation class so we can
|
||||
# know which relations not to even bother looking up
|
||||
if thing1s:
|
||||
from r2.models.last_modified import LastModified
|
||||
fullnames = [cls._thing1_cls._fullname_from_id36(thing1._id36)
|
||||
for thing1 in thing1s]
|
||||
timestamps = LastModified.get_multi(fullnames,
|
||||
cls._cf.column_family)
|
||||
|
||||
# build up a list of ids to look up, throwing out the ones that the
|
||||
# timestamp fetched above indicates are pointless
|
||||
ids = set()
|
||||
thing1_ids, thing2_ids = {}, {}
|
||||
for thing1 in thing1s:
|
||||
last_modification = timestamps.get(thing1._fullname)
|
||||
|
||||
if not last_modification:
|
||||
continue
|
||||
|
||||
for thing2 in thing2s:
|
||||
key = cls._rowkey(thing1._id36, thing2._id36)
|
||||
|
||||
if key in ids:
|
||||
continue
|
||||
|
||||
if thing2._date > last_modification:
|
||||
continue
|
||||
|
||||
ids.add(key)
|
||||
thing2_ids[thing2._id36] = thing2
|
||||
thing1_ids[thing1._id36] = thing1
|
||||
|
||||
# all relations must load these properties, even if unrequested
|
||||
if properties is not None:
|
||||
properties = set(properties)
|
||||
|
||||
properties.add('thing1_id')
|
||||
properties.add('thing2_id')
|
||||
|
||||
rels = {}
|
||||
if ids:
|
||||
rels = cls._byID(ids, properties=properties).values()
|
||||
|
||||
if thing1s_is_single and thing2s_is_single:
|
||||
if rels:
|
||||
assert len(rels) == 1
|
||||
return rels[0]
|
||||
else:
|
||||
raise NotFound("<%s %r>" % (cls.__name__,
|
||||
cls._rowkey(thing1s[0]._id36,
|
||||
thing2s[0]._id36)))
|
||||
|
||||
return dict(((thing1_ids[rel.thing1_id], thing2_ids[rel.thing2_id]), rel)
|
||||
for rel in rels)
|
||||
|
||||
@classmethod
|
||||
def _from_columns(cls, t_id, columns):
|
||||
# we deserialize relations a little specially so that we can
|
||||
# throw our toys on the floor if they don't have thing1_id and
|
||||
# thing2_id
|
||||
if not ('thing1_id' in columns and 'thing2_id' in columns
|
||||
and t_id == cls._rowkey(columns['thing1_id'], columns['thing2_id'])):
|
||||
raise InvariantException("Looked up %r with unmatched IDs (%r)"
|
||||
% (cls, t_id))
|
||||
|
||||
# if modifying this, check ThingBase._from_columns and see if
|
||||
# you should change it as well
|
||||
thing1_id, thing2_id = columns['thing1_id'], columns['thing2_id']
|
||||
t = cls(thing1_id = thing1_id, thing2_id = thing2_id)
|
||||
assert t._id == t_id
|
||||
t._orig = columns
|
||||
t._committed = True
|
||||
return t
|
||||
|
||||
@staticmethod
|
||||
def _rowkey(thing1_id36, thing2_id36):
|
||||
assert isinstance(thing1_id36, basestring) and isinstance(thing2_id36, basestring)
|
||||
return '%s_%s' % (thing1_id36, thing2_id36)
|
||||
|
||||
def _commit(self, *a, **kw):
|
||||
assert self._id == self._rowkey(self.thing1_id, self.thing2_id)
|
||||
|
||||
retval = ThingBase._commit(self, *a, **kw)
|
||||
|
||||
from r2.models.last_modified import LastModified
|
||||
fullname = self._thing1_cls._fullname_from_id36(self.thing1_id)
|
||||
LastModified.touch(fullname, self._cf.column_family)
|
||||
|
||||
return retval
|
||||
|
||||
@classmethod
|
||||
def _rel(cls, thing1_cls, thing2_cls):
|
||||
# should be implemented by abstract relations, like Vote
|
||||
raise NotImplementedError
|
||||
|
||||
@classmethod
|
||||
def _datekey(cls, date):
|
||||
# ick
|
||||
return str(long(cls._serialize_date(date)))
|
||||
|
||||
|
||||
def view_of(cls):
|
||||
"""Register a class as a view of a DenormalizedRelation.
|
||||
|
||||
Reference in New Issue
Block a user