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

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.Profile 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.Profile

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:e608c381a7dda7f4bd2a22da46f94857e4f1b640ff783dac7123f829f293009e","contract":["Profile encapsulates performance profiling data with sample types, period configuration, functions, locations, and samples","Profile.CheckValid enforces consistency between sample value lengths and declared sample types, rejecting mismatched dimensions","Profile serialization via Write and deserialization via Parse preserves profile structure and values across gzip protobuf round trips","Profile.Copy produces an independent deep copy of the profile whose mutations do not affect the original","Profile.Scale uniformly scales sample values across all samples by a specified factor"],"goal":"verify github.com/google/pprof/profile.Profile 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.Profile"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","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.Profile"],"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 (
	"bytes"
	"fmt"

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

// NewSampleProfile constructs a minimal valid Profile with sample types, period, locations, and samples.
func NewSampleProfile() *profile.Profile {
	fn := &profile.Function{
		ID:         1,
		Name:       "computeData",
		SystemName: "computeData",
		Filename:   "worker.go",
		StartLine:  10,
	}
	loc := &profile.Location{
		ID: 1,
		Line: []profile.Line{
			{Function: fn, Line: 15},
		},
	}
	return &profile.Profile{
		SampleType: []*profile.ValueType{
			{Type: "samples", Unit: "count"},
			{Type: "cpu", Unit: "nanoseconds"},
		},
		PeriodType: &profile.ValueType{Type: "cpu", Unit: "nanoseconds"},
		Period:     10000000,
		Function:   []*profile.Function{fn},
		Location:   []*profile.Location{loc},
		Sample: []*profile.Sample{
			{
				Location: []*profile.Location{loc},
				Value:    []int64{5, 50000000},
			},
		},
	}
}

// RoundTripProfile serializes a profile to gzip protobuf bytes and parses it back.
func RoundTripProfile(p *profile.Profile) (*profile.Profile, error) {
	var buf bytes.Buffer
	if err := p.Write(&buf); err != nil {
		return nil, fmt.Errorf("failed to write profile: %w", err)
	}
	parsed, err := profile.Parse(&buf)
	if err != nil {
		return nil, fmt.Errorf("failed to parse profile: %w", err)
	}
	return parsed, nil
}

// DeepCopyProfile creates an independent deep copy of the given Profile.
func DeepCopyProfile(p *profile.Profile) *profile.Profile {
	return p.Copy()
}

// ScaleProfile scales all sample values in the profile by the given factor.
func ScaleProfile(p *profile.Profile, factor float64) {
	p.Scale(factor)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/google/pprof/profile.Profile 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.Profile"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: Profile encapsulates performance profiling data with sample types, period configuration, functions, locations, and samples
	p := sample.NewSampleProfile()
	if len(p.SampleType) != 2 {
		fmt.Fprintf(os.Stderr, "expected 2 sample types, got %d\n", len(p.SampleType))
		os.Exit(1)
	}
	if p.SampleType[0].Type != "samples" || p.SampleType[1].Type != "cpu" {
		fmt.Fprintf(os.Stderr, "sample type names mismatch\n")
		os.Exit(1)
	}
	if p.Period != 10000000 || p.PeriodType.Type != "cpu" {
		fmt.Fprintf(os.Stderr, "period configuration mismatch\n")
		os.Exit(1)
	}
	if len(p.Sample) != 1 || len(p.Sample[0].Value) != 2 {
		fmt.Fprintf(os.Stderr, "sample counts mismatch\n")
		os.Exit(1)
	}
	if len(p.Location) != 1 || len(p.Function) != 1 {
		fmt.Fprintf(os.Stderr, "location or function count mismatch\n")
		os.Exit(1)
	}
	if err := p.CheckValid(); err != nil {
		fmt.Fprintf(os.Stderr, "expected valid profile to pass CheckValid: %v\n", err)
		os.Exit(1)
	}

	// Assertion 2: Profile.CheckValid enforces consistency between sample value lengths and declared sample types, rejecting mismatched dimensions
	invalidP := sample.NewSampleProfile()
	invalidP.Sample = append(invalidP.Sample, &profile.Sample{
		Location: invalidP.Location,
		Value:    []int64{1, 2, 3},
	})
	if err := invalidP.CheckValid(); err == nil {
		fmt.Fprintf(os.Stderr, "expected CheckValid to fail for mismatched sample value length, but got nil\n")
		os.Exit(1)
	}

	// Assertion 3: Profile serialization via Write and deserialization via Parse preserves profile structure and values across gzip protobuf round trips
	rt, err := sample.RoundTripProfile(p)
	if err != nil {
		fmt.Fprintf(os.Stderr, "round trip failed: %v\n", err)
		os.Exit(1)
	}
	if err := rt.CheckValid(); err != nil {
		fmt.Fprintf(os.Stderr, "round-tripped profile failed CheckValid: %v\n", err)
		os.Exit(1)
	}
	if len(rt.SampleType) != 2 || rt.SampleType[0].Type != "samples" || rt.SampleType[1].Type != "cpu" {
		fmt.Fprintf(os.Stderr, "round-trip sample type mismatch\n")
		os.Exit(1)
	}
	if len(rt.Sample) != 1 || rt.Sample[0].Value[0] != 5 || rt.Sample[0].Value[1] != 50000000 {
		fmt.Fprintf(os.Stderr, "round-trip sample values mismatch\n")
		os.Exit(1)
	}
	if len(rt.Location) != 1 || len(rt.Function) != 1 || rt.Function[0].Name != "computeData" {
		fmt.Fprintf(os.Stderr, "round-trip function metadata mismatch\n")
		os.Exit(1)
	}

	// Assertion 4: Profile.Copy produces an independent deep copy of the profile whose mutations do not affect the original
	cp := sample.DeepCopyProfile(p)
	if err := cp.CheckValid(); err != nil {
		fmt.Fprintf(os.Stderr, "copied profile failed CheckValid: %v\n", err)
		os.Exit(1)
	}
	cp.Sample[0].Value[0] = 999
	cp.Period = 20000000
	if p.Sample[0].Value[0] == 999 {
		fmt.Fprintf(os.Stderr, "mutating copy affected original profile sample value\n")
		os.Exit(1)
	}
	if p.Period == 20000000 {
		fmt.Fprintf(os.Stderr, "mutating copy affected original profile period\n")
		os.Exit(1)
	}

	// Assertion 5: Profile.Scale uniformly scales sample values across all samples by a specified factor
	scaleProfile := sample.DeepCopyProfile(p)
	sample.ScaleProfile(scaleProfile, 2.0)
	if scaleProfile.Sample[0].Value[0] != 10 {
		fmt.Fprintf(os.Stderr, "scaled sample value[0] mismatch: got %d, want 10\n", scaleProfile.Sample[0].Value[0])
		os.Exit(1)
	}
	if scaleProfile.Sample[0].Value[1] != 100000000 {
		fmt.Fprintf(os.Stderr, "scaled sample value[1] mismatch: got %d, want 100000000\n", scaleProfile.Sample[0].Value[1])
		os.Exit(1)
	}

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