diff options
Diffstat (limited to 'src/olpc/datastore/datastore.py')
| -rw-r--r-- | src/olpc/datastore/datastore.py | 119 |
1 files changed, 66 insertions, 53 deletions
diff --git a/src/olpc/datastore/datastore.py b/src/olpc/datastore/datastore.py index d197eda..3c99177 100644 --- a/src/olpc/datastore/datastore.py +++ b/src/olpc/datastore/datastore.py @@ -406,10 +406,20 @@ class DataStore(dbus.service.Object): @dbus.service.signal(DS_DBUS_INTERFACE, signature="s") def Created(self, uid): pass + + def _single_search(self, mountpoint, query, order_by, limit): + results, count = mountpoint.find(query.copy(), order_by, limit) + return list(results), count, 1 - def _multiway_search(self, query): + def _multiway_search(self, query, order_by=None, limit=None): mountpoints = query.pop('mountpoints', self.mountpoints) mountpoints = [self.mountpoints[str(m)] for m in mountpoints] + + + if len(mountpoints) == 1: + # Fast path the single mountpoint case + return self._single_search(mountpoints[0], query, order_by, limit) + results = [] # XXX: the merge will become *much* more complex in when # distributed versioning is implemented. @@ -417,7 +427,7 @@ class DataStore(dbus.service.Object): # some queries mutate the query-dict so we pass a copy each # time for mp in mountpoints: - result, count = mp.find(query.copy()) + result, count = mp.find(query.copy(), order_by, limit) results.append(result) # merge @@ -430,7 +440,7 @@ class DataStore(dbus.service.Object): # XXX: age/version check d[hit.id] = hit - return d, len(d) + return d, len(d), len(results) @dbus.service.method(DS_DBUS_INTERFACE, in_signature='a{sv}', @@ -482,8 +492,10 @@ class DataStore(dbus.service.Object): # distribute the search to all the mountpoints unless a # backingstore id set is specified - results, count = self._multiway_search(kwargs) - + # backends may be able to return sorted results, if there is + # only a single backend in the query we can use pre-sorted + # results directly + results, count, results_from = self._multiway_search(kwargs, order_by, limit) # ordering is difficult when we are dealing with sets from # more than one source. The model is this. @@ -491,64 +503,65 @@ class DataStore(dbus.service.Object): # in post processing. This allows use to assemble partially # database sorted results from many sources and quickly # combine them. - if order_by: - # resolve key names to columns - if isinstance(order_by, basestring): - order_by = [o.strip() for o in order_by.split(',')] - - if not isinstance(order_by, list): - logging.debug("bad query, order_by should be a list of property names") - order_by = None - - # generate a sort function based on the complete set of - # ordering criteria which includes the primary sort - # criteria as well to keep it stable. - def comparator(a, b): - # we only sort on properties so - for criteria in order_by: - mode = 1 # ascending - if criteria.startswith('-'): - mode = -1 - criteria = criteria[1:] - pa = a.get_property(criteria, None) - pb = b.get_property(criteria, None) - r = cmp(pa, pb) * mode - if r != 0: return r - return 0 - - - r = results.values() - r.sort(comparator) - results = r - else: - results = results.values() + if results_from > 1: + if order_by: + # resolve key names to columns + if isinstance(order_by, basestring): + order_by = [o.strip() for o in order_by.split(',')] + + if not isinstance(order_by, list): + logging.debug("bad query, order_by should be a list of property names") + order_by = None + + # generate a sort function based on the complete set of + # ordering criteria which includes the primary sort + # criteria as well to keep it stable. + def comparator(a, b): + # we only sort on properties so + for criteria in order_by: + mode = 1 # ascending + if criteria.startswith('-'): + mode = -1 + criteria = criteria[1:] + pa = a.get_property(criteria, None) + pb = b.get_property(criteria, None) + r = cmp(pa, pb) * mode + if r != 0: return r + return 0 + + + r = results.values() + r.sort(comparator) + results = r + else: + results = results.values() d = [] + c = 0 + if results_from == 1: + mp = results[0].backingstore.id + else: + mp = None + for r in results: - props = {} - props.update(r.properties) + props = r.properties # on versioning stores uid will be different # than r.id but must be set - if 'uid' not in props: - props['uid'] = r.id + #if 'uid' not in props: + props['uid'] = r.id - if 'mountpoint' not in props: - props['mountpoint'] = r.backingstore.id + #if 'mountpoint' not in props: + props['mountpoint'] = mp and mp or r.backingstore.id + + # filename not included in find results + #props['filename'] = '' - filename = '' - if include_files : - try: filename = r.filename - except KeyError: pass - # XXX: this means that find never shows the internally - # stored filename attribute (which is private) - props['filename'] = filename d.append(props) - - if limit: - d = d[offset: offset+limit] + c+= 1 + if limit and c > limit: break - return (d, len(results)) + return (d, len(d)) def get(self, uid, rev=None, mountpoint=None): mp = self._resolveMountpoint(mountpoint) |