Use the sort.Search api correctly.

service/datastore/query.go

Index: service/datastore/query.go
diff --git a/service/datastore/query.go b/service/datastore/query.go
index a68bca28686611eac9cead0e1feecf324c656c05..fc30f5f686808fc6f697a000c6be3bdf94e0cf65 100644
--- a/service/datastore/query.go
+++ b/service/datastore/query.go
@@ -270,11 +270,13 @@ func (q *Query) Eq(field string, values ...interface{}) *Query {
 					return
 				}
 				idx := sort.Search(len(s), func(i int) bool {
-					return s[i].Equal(&p)
+					// s[i] >= p is the same as:
+					return s[i].Equal(&p) || p.Less(&s[i])
 				})
-				if idx == len(s) {
-					s = append(s, p)
-					sort.Sort(s)
+				if idx == len(s) || !s[idx].Equal(&p) {
+					s = append(s, Property{})
+					copy(s[idx+1:], s[idx:])

[dnj, 2015/10/15 02:23:46]

nit: WDYT about making eqfilts a binheap?

+					s[idx] = p
 				}
 			}
 			q.eqFilts[field] = s