Source: index.go in package github.com/google/pprof/profile

Copyright 2016 Google Inc. All Rights Reserved. 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 profile

import (
	"fmt"
	"strconv"
	"strings"
)

SampleIndexByName returns the appropriate index for a value of sample index. If numeric, it returns the number, otherwise it looks up the text in the profile sample types.

func (p *Profile) SampleIndexByName(sampleIndex string) (int, error) {
	if sampleIndex == "" {
		if dst := p.DefaultSampleType; dst != "" {
			for i, t := range sampleTypes(p) {
				if t == dst {
					return i, nil
				}
			}

By default select the last sample value

		return len(p.SampleType) - 1, nil
	}
	if i, err := strconv.Atoi(sampleIndex); err == nil {
		if i < 0 || i >= len(p.SampleType) {
			return 0, fmt.Errorf("sample_index %s is outside the range [0..%d]", sampleIndex, len(p.SampleType)-1)
		}
		return i, nil
	}

Remove the inuse_ prefix to support legacy pprof options "inuse_space" and "inuse_objects" for profiles containing types "space" and "objects".

	noInuse := strings.TrimPrefix(sampleIndex, "inuse_")
	for i, t := range p.SampleType {
		if t.Type == sampleIndex || t.Type == noInuse {
			return i, nil
		}
	}

	return 0, fmt.Errorf("sample_index %q must be one of: %v", sampleIndex, sampleTypes(p))
}

func sampleTypes(p *Profile) []string {
	types := make([]string, len(p.SampleType))
	for i, t := range p.SampleType {
		types[i] = t.Type
	}
	return types