Switch to prefixed IDs and tell agents which Mac a message came from

internal/git/rename.go

@@ -0,0 +1,195 @@
+package git
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+func RenameRefs(repo string, rename func(string) string) error {
+	branches, err := run(repo, "for-each-ref", "--format=%(refname:short)", "refs/heads/byre/")
+	if err != nil {
+		return err
+	}
+	for _, b := range splitLines(branches) {
+		if rename(b) == b {
+			continue
+		}
+		_, err = run(repo, "branch", "-m", b, rename(b))
+		if err != nil {
+			return err
+		}
+	}
+
+	snaps, err := run(repo, "for-each-ref", "--format=%(objectname) %(refname)", "refs/byre/tasks/")
+	if err != nil {
+		return err
+	}
+	b := &strings.Builder{}
+	for _, l := range splitLines(snaps) {
+		sha, ref, _ := strings.Cut(l, " ")
+		if rename(ref) == ref {
+			continue
+		}
+		fmt.Fprintf(b, "create %s %s\ndelete %s %s\n", rename(ref), sha, ref, sha)
+	}
+	if b.Len() == 0 {
+		return nil
+	}
+	_, err = runInput(repo, nil, b.String(), "update-ref", "--stdin")
+	return err
+}
+
+func RepairWorktrees(repo string, paths []string) error {
+	if len(paths) == 0 {
+		return nil
+	}
+	_, err := run(repo, append([]string{"worktree", "repair"}, paths...)...)
+	return err
+}
+
+func RewriteNotes(repo string, rewrite func(string) string) error {
+	parent, stderr, code, err := runCode(repo, nil, "rev-parse", "--verify", "--quiet", NotesRef)
+	if err != nil {
+		return err
+	}
+	if code == 1 {
+		return nil
+	}
+	if code != 0 {
+		return fmt.Errorf("git rev-parse %s: exit status %d: %s", NotesRef, code, stderr)
+	}
+
+	listing, err := run(repo, "ls-tree", "-r", parent)
+	if err != nil {
+		return err
+	}
+	paths := map[string]string{}
+	shas := []string{}
+	for _, l := range splitLines(listing) {
+		meta, path, _ := strings.Cut(l, "\t")
+		fields := strings.Fields(meta)
+		paths[fields[2]] = path
+		shas = append(shas, fields[2])
+	}
+	if len(shas) == 0 {
+		return nil
+	}
+
+	contents, err := catBlobs(repo, shas)
+	if err != nil {
+		return err
+	}
+
+	dir, err := os.MkdirTemp("", "byre-notes-*")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(dir)
+
+	changed := []string{}
+	files := []string{}
+	for _, sha := range shas {
+		text := rewrite(contents[sha])
+		if text == contents[sha] {
+			continue
+		}
+		file := filepath.Join(dir, sha)
+		err = os.WriteFile(file, []byte(text), 0o644)
+		if err != nil {
+			return err
+		}
+		changed = append(changed, sha)
+		files = append(files, file)
+	}
+	if len(changed) == 0 {
+		return nil
+	}
+
+	blobs, err := runInput(repo, nil, strings.Join(files, "\n")+"\n", "hash-object", "-w", "--stdin-paths")
+	if err != nil {
+		return err
+	}
+	index := []string{"GIT_INDEX_FILE=" + filepath.Join(dir, "index")}
+	_, err = runEnv(repo, index, "read-tree", parent)
+	if err != nil {
+		return err
+	}
+	b := &strings.Builder{}
+	for i, blob := range splitLines(blobs) {
+		fmt.Fprintf(b, "100644 %s\t%s\n", blob, paths[changed[i]])
+	}
+	_, err = runInput(repo, index, b.String(), "update-index", "--index-info")
+	if err != nil {
+		return err
+	}
+	tree, err := runEnv(repo, index, "write-tree")
+	if err != nil {
+		return err
+	}
+	who, err := run(repo, "log", "-1", "--format=%cn%n%ce", parent)
+	if err != nil {
+		return err
+	}
+	name, email, _ := strings.Cut(who, "\n")
+	env := []string{"GIT_AUTHOR_NAME=" + name, "GIT_AUTHOR_EMAIL=" + email, "GIT_COMMITTER_NAME=" + name, "GIT_COMMITTER_EMAIL=" + email}
+	commit, err := runEnv(repo, env, "commit-tree", "-p", parent, "-m", "Rewrite byre ids in notes", tree)
+	if err != nil {
+		return err
+	}
+	_, err = run(repo, "update-ref", NotesRef, commit, parent)
+	return err
+}
+
+func catBlobs(repo string, shas []string) (map[string]string, error) {
+	out, err := runRaw(repo, strings.Join(shas, "\n")+"\n", "cat-file", "--batch")
+	if err != nil {
+		return nil, err
+	}
+	r := bufio.NewReader(strings.NewReader(out))
+	contents := map[string]string{}
+	for range shas {
+		header, err := r.ReadString('\n')
+		if err != nil {
+			return nil, err
+		}
+		fields := strings.Fields(header)
+		if len(fields) != 3 {
+			return nil, fmt.Errorf("git cat-file --batch: unexpected header %q", header)
+		}
+		size, err := strconv.Atoi(fields[2])
+		if err != nil {
+			return nil, err
+		}
+		body := make([]byte, size+1)
+		_, err = io.ReadFull(r, body)
+		if err != nil {
+			return nil, err
+		}
+		contents[fields[0]] = string(body[:size])
+	}
+	return contents, nil
+}
+
+func splitLines(out string) []string {
+	if out == "" {
+		return []string{}
+	}
+	return strings.Split(out, "\n")
+}
+
+func runRaw(dir, input string, args ...string) (string, error) {
+	out, stderr, code, err := runCodeInput(context.Background(), dir, nil, strings.NewReader(input), args...)
+	if err != nil {
+		return "", err
+	}
+	if code != 0 {
+		return "", fmt.Errorf("git %s: exit status %d: %s", strings.Join(args, " "), code, stderr)
+	}
+	return out, nil
+}