plugins/toolkit-activation/metric/new_histogram_intercepter.go

// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you 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 metric

import (
	"github.com/apache/skywalking-go/plugins/core/metrics"
	"github.com/apache/skywalking-go/plugins/core/operator"
	"github.com/apache/skywalking-go/toolkit/metric"
)

type NewHistogramInterceptor struct{}

func (h *NewHistogramInterceptor) BeforeInvoke(_ operator.Invocation) error {
	return nil
}

func (h *NewHistogramInterceptor) AfterInvoke(invocation operator.Invocation, result ...interface{}) error {
	enhanced := result[0].(operator.EnhancedInstance)
	metricName := invocation.Args()[0].(string)
	steps := invocation.Args()[1].([]float64)
	var opts []metrics.Opt
	for _, o := range invocation.Args()[2].([]metric.MeterOpt) {
		opt := o.(metrics.Opt)
		opts = append(opts, opt)
	}

	gauge := metrics.NewHistogram(metricName, steps, opts...)
	enhanced.SetSkyWalkingDynamicField(gauge)
	return nil
}