github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe: profile.Merge

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify github.com/google/pprof/profile.Merge in pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe
Demonstrate these symbols/APIs:
  - github.com/google/pprof/profile.Merge

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:938cbc6344ec139707efd85df8758aa38ebf9912b4c194f2fe713c13b06b701e","contract":["profile.Merge combines multiple profiles of identical structure by aggregating sample values"],"goal":"verify github.com/google/pprof/profile.Merge in pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe","kind":"HOW","packages":["pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe"],"schemaVersion":1,"symbols":["github.com/google/pprof/profile.Merge"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe"],"schemaVersion":1,"subject":"pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe","symbols":["github.com/google/pprof/profile.Merge"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe

github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe h1:QAinXoAFJdGQYztXn3VpFey7KCwpedbZ/EkzbplQ0cY=
github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe/go.mod h1:jl5iWTm0/hd5PjEYEOuwAJ57L/CibdZfrqZ5XA5GrCk=

package sample

import (
	"fmt"

	"github.com/google/pprof/profile"
)

// MakeProfile builds a minimal profile with a single function and sample value.
func MakeProfile(funcName string, sampleValue int64) *profile.Profile {
	fn := &profile.Function{
		ID:         1,
		Name:       funcName,
		SystemName: funcName,
		Filename:   "sample.go",
		StartLine:  1,
	}
	loc := &profile.Location{
		ID: 1,
		Line: []profile.Line{
			{
				Function: fn,
				Line:     1,
			},
		},
	}
	return &profile.Profile{
		SampleType: []*profile.ValueType{
			{Type: "samples", Unit: "count"},
		},
		PeriodType: &profile.ValueType{Type: "cpu", Unit: "nanoseconds"},
		Period:     1000000,
		Function:   []*profile.Function{fn},
		Location:   []*profile.Location{loc},
		Sample: []*profile.Sample{
			{
				Location: []*profile.Location{loc},
				Value:    []int64{sampleValue},
			},
		},
	}
}

// MergeProfiles merges multiple pprof profiles into a single profile using profile.Merge.
func MergeProfiles(profiles []*profile.Profile) (*profile.Profile, error) {
	if len(profiles) == 0 {
		return nil, fmt.Errorf("no profiles provided")
	}
	return profile.Merge(profiles)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/google/pprof/profile.Merge in pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/google/pprof@v0.0.0-20260906184651-6331bc6350fe"
  ],
  "symbols": [
    "github.com/google/pprof/profile.Merge"
  ]
}

package main

import (
	"fmt"
	"os"

	"github.com/google/pprof/profile"
	"sample"
)

func main() {
	// profile.Merge aggregates sample values across compatible profiles
	p1 := sample.MakeProfile("WorkerFunc", 100)
	p2 := sample.MakeProfile("WorkerFunc", 250)

	merged, err := sample.MergeProfiles([]*profile.Profile{p1, p2})
	if err != nil {
		fmt.Fprintf(os.Stderr, "MergeProfiles failed: %v\n", err)
		os.Exit(1)
	}

	if err := merged.CheckValid(); err != nil {
		fmt.Fprintf(os.Stderr, "merged profile is invalid: %v\n", err)
		os.Exit(1)
	}

	if len(merged.Sample) != 1 {
		fmt.Fprintf(os.Stderr, "expected 1 aggregated sample, got %d\n", len(merged.Sample))
		os.Exit(1)
	}

	if got := merged.Sample[0].Value[0]; got != 350 {
		fmt.Fprintf(os.Stderr, "expected merged value 350, got %d\n", got)
		os.Exit(1)
	}

	fmt.Println("All contract assertions passed.")
}