Merge pull request #8475 from heyitsanthony/mvcc-100-range

mvcc: don't allocate keys when computing Revisions

mvcc/index.go

@@ -85,6 +85,21 @@ func (ti *treeIndex) keyIndex(keyi *keyIndex) *keyIndex {
 	return nil
 }
 
+func (ti *treeIndex) visit(key, end []byte, f func(ki *keyIndex)) {
+	keyi, endi := &keyIndex{key: key}, &keyIndex{key: end}
+
+	ti.RLock()
+	defer ti.RUnlock()
+
+	ti.tree.AscendGreaterOrEqual(keyi, func(item btree.Item) bool {
+		if len(endi.key) > 0 && !item.Less(endi) {
+			return false
+		}
+		f(item.(*keyIndex))
+		return true
+	})
+}
+
 func (ti *treeIndex) Revisions(key, end []byte, atRev int64) (revs []revision) {
 	if end == nil {
 		rev, _, _, err := ti.Get(key, atRev)
@@ -93,8 +108,12 @@ func (ti *treeIndex) Revisions(key, end []byte, atRev int64) (revs []revision) {
 		}
 		return []revision{rev}
 	}
-	_, rev := ti.Range(key, end, atRev)
+	ti.visit(key, end, func(ki *keyIndex) {
-	return rev
+		if rev, _, _, err := ki.get(atRev); err == nil {
+			revs = append(revs, rev)
+		}
+	})
+	return revs
 }
 
 func (ti *treeIndex) Range(key, end []byte, atRev int64) (keys [][]byte, revs []revision) {
@@ -105,27 +124,12 @@ func (ti *treeIndex) Range(key, end []byte, atRev int64) (keys [][]byte, revs []
 		}
 		return [][]byte{key}, []revision{rev}
 	}
-
+	ti.visit(key, end, func(ki *keyIndex) {
-	keyi := &keyIndex{key: key}
+		if rev, _, _, err := ki.get(atRev); err == nil {
-	endi := &keyIndex{key: end}
-
-	ti.RLock()
-	defer ti.RUnlock()
-
-	ti.tree.AscendGreaterOrEqual(keyi, func(item btree.Item) bool {
-		if len(endi.key) > 0 && !item.Less(endi) {
-			return false
-		}
-		curKeyi := item.(*keyIndex)
-		rev, _, _, err := curKeyi.get(atRev)
-		if err != nil {
-			return true
-		}
 			revs = append(revs, rev)
-		keys = append(keys, curKeyi.key)
+			keys = append(keys, ki.key)
-		return true
+		}
 	})
-
 	return keys, revs
 }
 

mvcc/kvstore_bench_test.go

@@ -45,22 +45,34 @@ func BenchmarkStorePut(b *testing.B) {
 	}
 }
 
-func BenchmarkStoreRangeOneKey(b *testing.B) {
+func BenchmarkStoreRangeKey1(b *testing.B)   { benchmarkStoreRange(b, 1) }
+func BenchmarkStoreRangeKey100(b *testing.B) { benchmarkStoreRange(b, 100) }
+
+func benchmarkStoreRange(b *testing.B, n int) {
 	var i fakeConsistentIndex
 	be, tmpPath := backend.NewDefaultTmpBackend()
 	s := NewStore(be, &lease.FakeLessor{}, &i)
 	defer cleanup(s, be, tmpPath)
 
 	// 64 byte key/val
-	key, val := createBytesSlice(64, 1), createBytesSlice(64, 1)
+	keys, val := createBytesSlice(64, n), createBytesSlice(64, 1)
-	s.Put(key[0], val[0], lease.NoLease)
+	for i := range keys {
+		s.Put(keys[i], val[0], lease.NoLease)
+	}
 	// Force into boltdb tx instead of backend read tx.
 	s.Commit()
 
+	var begin, end []byte
+	if n == 1 {
+		begin, end = keys[0], nil
+	} else {
+		begin, end = []byte{}, []byte{}
+	}
+
 	b.ReportAllocs()
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		s.Range(key[0], nil, RangeOptions{})
+		s.Range(begin, end, RangeOptions{})
 	}
 }