chore(godeltaprof): Add github action notifying golang profiler chang…

…es (#49)

.github/workflows/check_golang_profiler_changes.yml

@@ -0,0 +1,23 @@
+name: "godeltaprof: check golang runtime profiler changes"
+
+on:
+  schedule:
+    - cron: '20 4 * * *'
+  workflow_dispatch:
+
+jobs:
+  check_golang_profiler_changes:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - uses: actions/setup-go@v3
+        with:
+          go-version: '1.20'
+      - name: Check golang runtime profiler changes
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          cd godeltaprof/compat/cmd/check_golang_profiler_changes && go run main.go \
+            -git.user.name="github-actions[bot]" \
+            -git.user.email="41898282+github-actions[bot]@users.noreply.github.com"

godeltaprof/compat/README.md

@@ -0,0 +1 @@
+This module is separate from the godeltaprof to keep the godeltaprof zero dependencies.

godeltaprof/compat/cmd/check_golang_profiler_changes/.gitignore

@@ -0,0 +1 @@
+go_repo/

godeltaprof/compat/cmd/check_golang_profiler_changes/README.md

@@ -0,0 +1,7 @@
+This command tracks latest commits in src/runtime/mprof.go and src/runtime/pprof
+If there are new commits found it creates a PR to update [last_known_go_commits.json](last_known_go_commits.json) file
+
+The idea is that godeltaprof was based on copy of go runtime internals, so if internals change then we may want to change
+the godeltaprof as well. 
+
+See [godeltaprof incorrectly scales mutex profile](https://github.com/grafana/pyroscope-go/issues/47)

godeltaprof/compat/cmd/check_golang_profiler_changes/last_known_golang_changes.json

@@ -0,0 +1,4 @@
+{
+  "mprof": "1c0035401358c8bfc2ff646b1d950da5fcd6b355",
+  "pprof": "e8a767b609a32972aca848b806700b3f7ddd34d3"
+}

godeltaprof/compat/cmd/check_golang_profiler_changes/main.go

@@ -0,0 +1,256 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"path"
+	"regexp"
+	"strings"
+	"time"
+)
+
+var gitUserName = flag.String("git.user.name", "", "git user name")
+var gitUserEmail = flag.String("git.user.email", "", "git user email")
+
+const goRepoURL = "https://github.com/golang/go.git"
+
+const myRemote = "origin"
+
+const mprof = "src/runtime/mprof.go"
+const pprof = "src/runtime/pprof"
+const repoDir = "go_repo"
+const latestCommitsFile = "last_known_golang_changes.json"
+const label = "godeltaprof: check_golang_profiler_changes"
+
+type Commits struct {
+	Mprof string `json:"mprof"`
+	Pprof string `json:"pprof"`
+}
+
+var known Commits
+var current Commits
+
+var shMy = sh{}
+var shGo = sh{wd: getRepoDir()}
+
+func main() {
+	flag.Parse()
+
+	updateGoRepo()
+	loadLastKnownCommits()
+	loadCurrentCommits()
+	if known == current {
+		log.Println("no new commits")
+		return
+	}
+	writeLastKnownCommits()
+	createOrUpdatePR()
+}
+
+func createOrUpdatePR() {
+	msg := ""
+	const commitUrl = "https://github.com/golang/go/commit/"
+	msg += "This PR is created by godeltaprof/compat/cmd/check_golang_profiler_changes/main.go to notify src/runtime/mprof.go or src/runtime/pprof in golang are updated.\n"
+	msg += "Please take look at the golang commits and update godeltaprof accordingly if needed.\n"
+	msg += "Merge the PR to acknowledge golang runtime changes and state no further actions needed for godeltaprof.\n\n"
+
+	if current.Mprof != known.Mprof {
+		msg += mprof
+		msg += "\n"
+		msg += "last known [" + known.Mprof + "](" + commitUrl + known.Mprof + ")\n"
+		msg += "current    [" + current.Mprof + "](" + commitUrl + current.Mprof + ")\n"
+		commits, _ := shGo.sh(fmt.Sprintf("git log  %s..%s -- %s", known.Mprof, current.Mprof, mprof))
+		msg += "```\n"
+		msg += commits
+		msg += "\n"
+		msg += "```\n"
+	}
+	//git log  1c0035401358c8bfc2ff646b1d950da5fcd6b355..a7c3de705287d56e3bea8a84ed9a56e4102d3f39 -- src/runtime/mprof.go
+
+	if current.Pprof != known.Pprof {
+		msg += pprof
+		msg += "\n"
+		msg += "last known [" + known.Pprof + "](" + commitUrl + known.Pprof + ")\n"
+		msg += "current    [" + current.Pprof + "](" + commitUrl + current.Pprof + ")\n"
+
+		commits, _ := shGo.sh(fmt.Sprintf("git log  %s..%s -- %s", known.Pprof, current.Pprof, pprof))
+		msg += "```\n"
+		msg += commits
+		msg += "\n"
+		msg += "```\n"
+	}
+	log.Println(msg)
+
+	prs := getPullRequests()
+	found := -1
+out:
+	for i, pr := range prs {
+		for j := range pr.Labels {
+			if pr.Labels[j].Name == label {
+				found = i
+				break out
+			}
+		}
+	}
+	if found == -1 {
+		log.Println("existing PR not found, creating a new one")
+		createPR(msg)
+	} else {
+		log.Printf("found existing PR %+v. updating.", prs[found])
+		updatePR(msg, prs[found])
+	}
+
+}
+
+func updatePR(msg string, request PullRequest) {
+	branchName := createBranchName()
+	commitMessage := createCommitMessage()
+
+	shMy.sh(fmt.Sprintf("git checkout -b %s", branchName))
+	if *gitUserName != "" && *gitUserEmail != "" {
+		shMy.sh(fmt.Sprintf("git config user.name '%s'", *gitUserName))
+		shMy.sh(fmt.Sprintf("git config user.email '%s'", *gitUserEmail))
+	}
+	shMy.sh(fmt.Sprintf("git commit -am '%s'", commitMessage))
+	shMy.sh(fmt.Sprintf("git push -f %s %s:%s", myRemote, branchName, request.HeadRefName))
+
+	shMy.sh(fmt.Sprintf("gh pr edit %d --body '%s'", request.Number, msg))
+
+}
+
+func createPR(msg string) {
+	branchName := createBranchName()
+	commitMessage := createCommitMessage()
+
+	shMy.sh(fmt.Sprintf("git checkout -b %s", branchName))
+	if *gitUserName != "" && *gitUserEmail != "" {
+		shMy.sh(fmt.Sprintf("git config user.name '%s'", *gitUserName))
+		shMy.sh(fmt.Sprintf("git config user.email '%s'", *gitUserEmail))
+	}
+	shMy.sh(fmt.Sprintf("git commit -am '%s'", commitMessage))
+	shMy.sh(fmt.Sprintf("git push %s %s", myRemote, branchName))
+
+	shMy.sh(fmt.Sprintf("gh pr create --title '%s' --body '%s' --label '%s' ", commitMessage, msg, label))
+
+}
+
+func createCommitMessage() string {
+	return fmt.Sprintf("chore(check_golang_profiler_changes): acknowledge new golang profiler changes")
+}
+
+func createBranchName() string {
+	return fmt.Sprintf("check_golang_profiler_changes_%d", time.Now().Unix())
+}
+
+func writeLastKnownCommits() {
+	bs, err := json.MarshalIndent(&current, "", "  ")
+	requireNoError(err, "marshal current commits")
+	err = os.WriteFile(latestCommitsFile, bs, 0666)
+	requireNoError(err, "write current commits")
+}
+
+func loadCurrentCommits() {
+	current.Mprof = checkLatestCommit(mprof)
+	current.Pprof = checkLatestCommit(pprof)
+
+	log.Printf("current commits: %+v\n", current)
+}
+
+func checkLatestCommit(repoPath string) string {
+	s, _ := shGo.sh(fmt.Sprintf("git log -- %s | head -n 1", repoPath))
+	re := regexp.MustCompile("commit ([a-f0-9]{40})")
+	match := re.FindStringSubmatch(s)
+	if match == nil {
+		requireNoError(fmt.Errorf("no commit found for %s %s", repoPath, s), "commit regex")
+	}
+	commit := match[1]
+	log.Println("latest commit ", repoPath, commit)
+	return commit
+}
+
+func loadLastKnownCommits() {
+	bs, err := os.ReadFile(latestCommitsFile)
+	requireNoError(err, "read known_commits.json")
+	err = json.Unmarshal(bs, &known)
+	requireNoError(err, "unmarshal known_commits.json")
+	log.Printf("known commits: %+v\n", known)
+}
+
+func updateGoRepo() {
+	_, err := os.Stat(repoDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			shMy.sh(fmt.Sprintf("git clone %s %s", goRepoURL, repoDir))
+			log.Println("git clone done")
+		} else {
+			log.Fatal(err)
+		}
+	} else {
+		log.Println("repo exists")
+	}
+
+	shGo.sh("git checkout master && git pull")
+	log.Println("git pull done")
+}
+
+func requireNoError(err error, msg string) {
+	if err != nil {
+		log.Fatalf("msg %s err %v", msg, err)
+	}
+}
+
+func getRepoDir() string {
+	cwd, err := os.Getwd()
+	requireNoError(err, "cwd")
+	return path.Join(cwd, repoDir)
+}
+
+type PullRequest struct {
+	BaseRefName string       `json:"baseRefName"`
+	HeadRefName string       `json:"headRefName"`
+	Id          string       `json:"id"`
+	Labels      []IssueLabel `json:"labels"`
+	Number      int          `json:"number"`
+}
+
+type IssueLabel struct {
+	Name string `json:"name"`
+}
+
+func getPullRequests() []PullRequest {
+	s := sh{}
+	stdout, _ := s.sh("gh pr list --json 'id,number,labels,baseRefName,headRefName'")
+	var prs []PullRequest
+	err := json.Unmarshal([]byte(stdout), &prs)
+	requireNoError(err, "unmarshal prs")
+	log.Println("prs", prs)
+	return prs
+}
+
+type sh struct {
+	wd string
+}
+
+func (s *sh) sh(sh string) (string, string) {
+	return s.cmd("/bin/sh", "-c", sh)
+}
+
+func (s *sh) cmd(cmdArgs ...string) (string, string) {
+	log.Printf("cmd %s\n", strings.Join(cmdArgs, " "))
+	cmd := exec.Command(cmdArgs[0], cmdArgs[1:]...)
+	cmd.Dir = s.wd
+	stdout := bytes.NewBuffer(nil)
+	stderr := bytes.NewBuffer(nil)
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+	err := cmd.Run()
+	fmt.Println(stdout.String())
+	fmt.Println(stderr.String())
+	requireNoError(err, strings.Join(cmdArgs, " "))
+	return stdout.String(), stderr.String()
+}