Adding upstream version 1.34.4.

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

plugins/inputs/opensearch_query/aggregation.go

@@ -0,0 +1,60 @@
+package opensearch_query
+
+import (
+	"encoding/json"
+)
+
+type aggregationRequest interface {
+	addAggregation(string, string, string) error
+}
+
+type aggregationFunction struct {
+	aggType string
+	field   string
+	size    int
+	missing string
+
+	nested aggregationRequest
+}
+
+// MarshalJSON serializes the aggregationFunction into JSON format.
+func (a *aggregationFunction) MarshalJSON() ([]byte, error) {
+	agg := make(map[string]interface{})
+	field := map[string]interface{}{"field": a.field}
+	if t := getAggregationFunctionType(a.aggType); t == "bucket" {
+		// We'll use the default size of 10 if it hasn't been set; size == 0 is illegal in a bucket aggregation
+		if a.size == 0 {
+			a.size = 10
+		}
+		field["size"] = a.size
+	}
+	if a.missing != "" {
+		field["missing"] = a.missing
+	}
+
+	agg[a.aggType] = field
+
+	if a.nested != nil {
+		agg["aggregations"] = a.nested
+	}
+	return json.Marshal(agg)
+}
+
+func (a *aggregationFunction) setSize(size int) {
+	a.size = size
+}
+
+func (a *aggregationFunction) setMissing(missing string) {
+	a.missing = missing
+}
+
+func getAggregationFunctionType(field string) string {
+	switch field {
+	case "avg", "sum", "min", "max", "value_count", "stats", "extended_stats", "percentiles":
+		return "metric"
+	case "terms":
+		return "bucket"
+	default:
+		return ""
+	}
+}