vendor: github.com/prometheus/client_golang v1.12.1

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/google.golang.org/grpc/internal/serviceconfig/serviceconfig.go

@@ -0,0 +1,90 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * 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 serviceconfig contains utility functions to parse service config.
+package serviceconfig
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/grpclog"
+	externalserviceconfig "google.golang.org/grpc/serviceconfig"
+)
+
+// BalancerConfig is the balancer config part that service config's
+// loadBalancingConfig fields can be unmarshalled to. It's a json unmarshaller.
+//
+// https://github.com/grpc/grpc-proto/blob/54713b1e8bc6ed2d4f25fb4dff527842150b91b2/grpc/service_config/service_config.proto#L247
+type BalancerConfig struct {
+	Name   string
+	Config externalserviceconfig.LoadBalancingConfig
+}
+
+type intermediateBalancerConfig []map[string]json.RawMessage
+
+// UnmarshalJSON implements json unmarshaller.
+func (bc *BalancerConfig) UnmarshalJSON(b []byte) error {
+	var ir intermediateBalancerConfig
+	err := json.Unmarshal(b, &ir)
+	if err != nil {
+		return err
+	}
+
+	for i, lbcfg := range ir {
+		if len(lbcfg) != 1 {
+			return fmt.Errorf("invalid loadBalancingConfig: entry %v does not contain exactly 1 policy/config pair: %q", i, lbcfg)
+		}
+		var (
+			name    string
+			jsonCfg json.RawMessage
+		)
+		// Get the key:value pair from the map.
+		for name, jsonCfg = range lbcfg {
+		}
+		builder := balancer.Get(name)
+		if builder == nil {
+			// If the balancer is not registered, move on to the next config.
+			// This is not an error.
+			continue
+		}
+		bc.Name = name
+
+		parser, ok := builder.(balancer.ConfigParser)
+		if !ok {
+			if string(jsonCfg) != "{}" {
+				grpclog.Warningf("non-empty balancer configuration %q, but balancer does not implement ParseConfig", string(jsonCfg))
+			}
+			// Stop at this, though the builder doesn't support parsing config.
+			return nil
+		}
+
+		cfg, err := parser.ParseConfig(jsonCfg)
+		if err != nil {
+			return fmt.Errorf("error parsing loadBalancingConfig for policy %q: %v", name, err)
+		}
+		bc.Config = cfg
+		return nil
+	}
+	// This is reached when the for loop iterates over all entries, but didn't
+	// return. This means we had a loadBalancingConfig slice but did not
+	// encounter a registered policy. The config is considered invalid in this
+	// case.
+	return fmt.Errorf("invalid loadBalancingConfig: no supported policies found")
+}