Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/processors/snmp_lookup/backlog.go

@@ -0,0 +1,105 @@
+package snmp_lookup
+
+import (
+	"container/list"
+	"sync"
+
+	"github.com/influxdata/telegraf"
+)
+
+type backlogEntry struct {
+	metric   telegraf.Metric
+	agent    string
+	index    string
+	resolved bool
+}
+
+type backlog struct {
+	elements *list.List
+	ordered  bool
+
+	acc telegraf.Accumulator
+	log telegraf.Logger
+
+	sync.Mutex
+}
+
+func newBacklog(acc telegraf.Accumulator, log telegraf.Logger, ordered bool) *backlog {
+	return &backlog{
+		elements: list.New(),
+		ordered:  ordered,
+		acc:      acc,
+		log:      log,
+	}
+}
+
+func (b *backlog) destroy() int {
+	b.Lock()
+	defer b.Unlock()
+
+	count := b.elements.Len()
+	for {
+		e := b.elements.Front()
+		if e == nil {
+			break
+		}
+		entry := e.Value.(backlogEntry)
+		b.log.Debugf("Adding unresolved metric %v", entry.metric)
+		b.acc.AddMetric(entry.metric)
+
+		b.elements.Remove(e)
+	}
+
+	return count
+}
+
+func (b *backlog) push(agent, index string, m telegraf.Metric) {
+	e := backlogEntry{
+		metric: m,
+		agent:  agent,
+		index:  index,
+	}
+	b.Lock()
+	defer b.Unlock()
+	_ = b.elements.PushBack(e)
+}
+
+func (b *backlog) resolve(agent string, tm *tagMap) {
+	b.Lock()
+	defer b.Unlock()
+
+	var outOfOrder bool
+	var forRemoval []*list.Element
+	e := b.elements.Front()
+	for e != nil {
+		entry := e.Value.(backlogEntry)
+
+		// Check if we can resolve the element
+		if entry.agent == agent {
+			tags, found := tm.rows[entry.index]
+			if found {
+				for k, v := range tags {
+					entry.metric.AddTag(k, v)
+				}
+			} else {
+				b.log.Warnf("Cannot resolve metrics because index %q not found for agent %q!", entry.index, agent)
+			}
+			entry.resolved = true
+		}
+
+		// Check if we can release the metric in ordered mode...
+		outOfOrder = outOfOrder || !entry.resolved
+		if entry.resolved && (!b.ordered || !outOfOrder) {
+			b.acc.AddMetric(entry.metric)
+			forRemoval = append(forRemoval, e)
+		}
+		e.Value = entry
+		e = e.Next()
+	}
+
+	// We need to remove the elements in a separate loop to not interfere with
+	// the list iteration above.
+	for _, e := range forRemoval {
+		b.elements.Remove(e)
+	}
+}