VOL-2017 voltha-lib moved from voltha-go;
release version 2.2.1

Based on voltha-go commit 5259f8e52b3e3f5c7ad422a4b0e506e1d07f6b36

Change-Id: I8bbecdf456e420714a4016120eafc0d237c80565
diff --git a/vendor/github.com/bsm/sarama-cluster/offsets.go b/vendor/github.com/bsm/sarama-cluster/offsets.go
new file mode 100644
index 0000000..4223ac5
--- /dev/null
+++ b/vendor/github.com/bsm/sarama-cluster/offsets.go
@@ -0,0 +1,69 @@
+package cluster
+
+import (
+	"sync"
+
+	"github.com/Shopify/sarama"
+)
+
+// OffsetStash allows to accumulate offsets and
+// mark them as processed in a bulk
+type OffsetStash struct {
+	offsets map[topicPartition]offsetInfo
+	mu      sync.Mutex
+}
+
+// NewOffsetStash inits a blank stash
+func NewOffsetStash() *OffsetStash {
+	return &OffsetStash{offsets: make(map[topicPartition]offsetInfo)}
+}
+
+// MarkOffset stashes the provided message offset
+func (s *OffsetStash) MarkOffset(msg *sarama.ConsumerMessage, metadata string) {
+	s.MarkPartitionOffset(msg.Topic, msg.Partition, msg.Offset, metadata)
+}
+
+// MarkPartitionOffset stashes the offset for the provided topic/partition combination
+func (s *OffsetStash) MarkPartitionOffset(topic string, partition int32, offset int64, metadata string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	key := topicPartition{Topic: topic, Partition: partition}
+	if info := s.offsets[key]; offset >= info.Offset {
+		info.Offset = offset
+		info.Metadata = metadata
+		s.offsets[key] = info
+	}
+}
+
+// ResetPartitionOffset stashes the offset for the provided topic/partition combination.
+// Difference between ResetPartitionOffset and MarkPartitionOffset is that, ResetPartitionOffset supports earlier offsets
+func (s *OffsetStash) ResetPartitionOffset(topic string, partition int32, offset int64, metadata string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	key := topicPartition{Topic: topic, Partition: partition}
+	if info := s.offsets[key]; offset <= info.Offset {
+		info.Offset = offset
+		info.Metadata = metadata
+		s.offsets[key] = info
+	}
+}
+
+// ResetOffset stashes the provided message offset
+// See ResetPartitionOffset for explanation
+func (s *OffsetStash) ResetOffset(msg *sarama.ConsumerMessage, metadata string) {
+	s.ResetPartitionOffset(msg.Topic, msg.Partition, msg.Offset, metadata)
+}
+
+// Offsets returns the latest stashed offsets by topic-partition
+func (s *OffsetStash) Offsets() map[string]int64 {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	res := make(map[string]int64, len(s.offsets))
+	for tp, info := range s.offsets {
+		res[tp.String()] = info.Offset
+	}
+	return res
+}