VOL-4077: Improve storage usage on etcd
- Do away with unnecessary data storage on etcd if it can be
reconciled on adapter restart
- For data that needs storage, use lesser footprint if possible
- Use write-through-cache for all data stored on etcd via
resource manager module
- Use ResourceManager module per interface to localize lock
contention per PON port
Change-Id: I21d38216fab195d738a446b3f96a00251569e38b
diff --git a/vendor/github.com/opencord/voltha-lib-go/v5/pkg/db/kvstore/kvutils.go b/vendor/github.com/opencord/voltha-lib-go/v5/pkg/db/kvstore/kvutils.go
new file mode 100644
index 0000000..ca57542
--- /dev/null
+++ b/vendor/github.com/opencord/voltha-lib-go/v5/pkg/db/kvstore/kvutils.go
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package kvstore
+
+import (
+ "context"
+ "fmt"
+ "math"
+ "math/rand"
+ "time"
+)
+
+const (
+ minRetryInterval = 100
+ maxRetryInterval = 5000
+ incrementalFactor = 1.2
+ jitter = 0.2
+)
+
+// ToString converts an interface value to a string. The interface should either be of
+// a string type or []byte. Otherwise, an error is returned.
+func ToString(value interface{}) (string, error) {
+ switch t := value.(type) {
+ case []byte:
+ return string(value.([]byte)), nil
+ case string:
+ return value.(string), nil
+ default:
+ return "", fmt.Errorf("unexpected-type-%T", t)
+ }
+}
+
+// ToByte converts an interface value to a []byte. The interface should either be of
+// a string type or []byte. Otherwise, an error is returned.
+func ToByte(value interface{}) ([]byte, error) {
+ switch t := value.(type) {
+ case []byte:
+ return value.([]byte), nil
+ case string:
+ return []byte(value.(string)), nil
+ default:
+ return nil, fmt.Errorf("unexpected-type-%T", t)
+ }
+}
+
+// backoff waits an amount of time that is proportional to the attempt value. The wait time in a range of
+// minRetryInterval and maxRetryInterval.
+func backoff(ctx context.Context, attempt int) error {
+ if attempt == 0 {
+ return nil
+ }
+ backoff := int(minRetryInterval + incrementalFactor*math.Exp(float64(attempt)))
+ backoff *= 1 + int(jitter*(rand.Float64()*2-1))
+ if backoff > maxRetryInterval {
+ backoff = maxRetryInterval
+ }
+ ticker := time.NewTicker(time.Duration(backoff) * time.Millisecond)
+ defer ticker.Stop()
+ select {
+ case <-ctx.Done():
+ return ctx.Err()
+ case <-ticker.C:
+ }
+ return nil
+}