diff options
Diffstat (limited to 'src/cmd/go/internal/modfetch/codehost/vcs.go')
-rw-r--r-- | src/cmd/go/internal/modfetch/codehost/vcs.go | 616 |
1 files changed, 616 insertions, 0 deletions
diff --git a/src/cmd/go/internal/modfetch/codehost/vcs.go b/src/cmd/go/internal/modfetch/codehost/vcs.go new file mode 100644 index 0000000..c2cca08 --- /dev/null +++ b/src/cmd/go/internal/modfetch/codehost/vcs.go @@ -0,0 +1,616 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package codehost + +import ( + "errors" + "fmt" + "internal/lazyregexp" + "io" + "io/fs" + "os" + "path/filepath" + "sort" + "strconv" + "strings" + "sync" + "time" + + "cmd/go/internal/lockedfile" + "cmd/go/internal/par" + "cmd/go/internal/str" +) + +// A VCSError indicates an error using a version control system. +// The implication of a VCSError is that we know definitively where +// to get the code, but we can't access it due to the error. +// The caller should report this error instead of continuing to probe +// other possible module paths. +// +// TODO(golang.org/issue/31730): See if we can invert this. (Return a +// distinguished error for “repo not found” and treat everything else +// as terminal.) +type VCSError struct { + Err error +} + +func (e *VCSError) Error() string { return e.Err.Error() } + +func vcsErrorf(format string, a ...interface{}) error { + return &VCSError{Err: fmt.Errorf(format, a...)} +} + +func NewRepo(vcs, remote string) (Repo, error) { + type key struct { + vcs string + remote string + } + type cached struct { + repo Repo + err error + } + c := vcsRepoCache.Do(key{vcs, remote}, func() interface{} { + repo, err := newVCSRepo(vcs, remote) + if err != nil { + err = &VCSError{err} + } + return cached{repo, err} + }).(cached) + + return c.repo, c.err +} + +var vcsRepoCache par.Cache + +type vcsRepo struct { + mu lockedfile.Mutex // protects all commands, so we don't have to decide which are safe on a per-VCS basis + + remote string + cmd *vcsCmd + dir string + + tagsOnce sync.Once + tags map[string]bool + + branchesOnce sync.Once + branches map[string]bool + + fetchOnce sync.Once + fetchErr error +} + +func newVCSRepo(vcs, remote string) (Repo, error) { + if vcs == "git" { + return newGitRepo(remote, false) + } + cmd := vcsCmds[vcs] + if cmd == nil { + return nil, fmt.Errorf("unknown vcs: %s %s", vcs, remote) + } + if !strings.Contains(remote, "://") { + return nil, fmt.Errorf("invalid vcs remote: %s %s", vcs, remote) + } + + r := &vcsRepo{remote: remote, cmd: cmd} + var err error + r.dir, r.mu.Path, err = WorkDir(vcsWorkDirType+vcs, r.remote) + if err != nil { + return nil, err + } + + if cmd.init == nil { + return r, nil + } + + unlock, err := r.mu.Lock() + if err != nil { + return nil, err + } + defer unlock() + + if _, err := os.Stat(filepath.Join(r.dir, "."+vcs)); err != nil { + if _, err := Run(r.dir, cmd.init(r.remote)); err != nil { + os.RemoveAll(r.dir) + return nil, err + } + } + return r, nil +} + +const vcsWorkDirType = "vcs1." + +type vcsCmd struct { + vcs string // vcs name "hg" + init func(remote string) []string // cmd to init repo to track remote + tags func(remote string) []string // cmd to list local tags + tagRE *lazyregexp.Regexp // regexp to extract tag names from output of tags cmd + branches func(remote string) []string // cmd to list local branches + branchRE *lazyregexp.Regexp // regexp to extract branch names from output of tags cmd + badLocalRevRE *lazyregexp.Regexp // regexp of names that must not be served out of local cache without doing fetch first + statLocal func(rev, remote string) []string // cmd to stat local rev + parseStat func(rev, out string) (*RevInfo, error) // cmd to parse output of statLocal + fetch []string // cmd to fetch everything from remote + latest string // name of latest commit on remote (tip, HEAD, etc) + readFile func(rev, file, remote string) []string // cmd to read rev's file + readZip func(rev, subdir, remote, target string) []string // cmd to read rev's subdir as zip file + doReadZip func(dst io.Writer, workDir, rev, subdir, remote string) error // arbitrary function to read rev's subdir as zip file +} + +var re = lazyregexp.New + +var vcsCmds = map[string]*vcsCmd{ + "hg": { + vcs: "hg", + init: func(remote string) []string { + return []string{"hg", "clone", "-U", "--", remote, "."} + }, + tags: func(remote string) []string { + return []string{"hg", "tags", "-q"} + }, + tagRE: re(`(?m)^[^\n]+$`), + branches: func(remote string) []string { + return []string{"hg", "branches", "-c", "-q"} + }, + branchRE: re(`(?m)^[^\n]+$`), + badLocalRevRE: re(`(?m)^(tip)$`), + statLocal: func(rev, remote string) []string { + return []string{"hg", "log", "-l1", "-r", rev, "--template", "{node} {date|hgdate} {tags}"} + }, + parseStat: hgParseStat, + fetch: []string{"hg", "pull", "-f"}, + latest: "tip", + readFile: func(rev, file, remote string) []string { + return []string{"hg", "cat", "-r", rev, file} + }, + readZip: func(rev, subdir, remote, target string) []string { + pattern := []string{} + if subdir != "" { + pattern = []string{"-I", subdir + "/**"} + } + return str.StringList("hg", "archive", "-t", "zip", "--no-decode", "-r", rev, "--prefix=prefix/", pattern, "--", target) + }, + }, + + "svn": { + vcs: "svn", + init: nil, // no local checkout + tags: func(remote string) []string { + return []string{"svn", "list", "--", strings.TrimSuffix(remote, "/trunk") + "/tags"} + }, + tagRE: re(`(?m)^(.*?)/?$`), + statLocal: func(rev, remote string) []string { + suffix := "@" + rev + if rev == "latest" { + suffix = "" + } + return []string{"svn", "log", "-l1", "--xml", "--", remote + suffix} + }, + parseStat: svnParseStat, + latest: "latest", + readFile: func(rev, file, remote string) []string { + return []string{"svn", "cat", "--", remote + "/" + file + "@" + rev} + }, + doReadZip: svnReadZip, + }, + + "bzr": { + vcs: "bzr", + init: func(remote string) []string { + return []string{"bzr", "branch", "--use-existing-dir", "--", remote, "."} + }, + fetch: []string{ + "bzr", "pull", "--overwrite-tags", + }, + tags: func(remote string) []string { + return []string{"bzr", "tags"} + }, + tagRE: re(`(?m)^\S+`), + badLocalRevRE: re(`^revno:-`), + statLocal: func(rev, remote string) []string { + return []string{"bzr", "log", "-l1", "--long", "--show-ids", "-r", rev} + }, + parseStat: bzrParseStat, + latest: "revno:-1", + readFile: func(rev, file, remote string) []string { + return []string{"bzr", "cat", "-r", rev, file} + }, + readZip: func(rev, subdir, remote, target string) []string { + extra := []string{} + if subdir != "" { + extra = []string{"./" + subdir} + } + return str.StringList("bzr", "export", "--format=zip", "-r", rev, "--root=prefix/", "--", target, extra) + }, + }, + + "fossil": { + vcs: "fossil", + init: func(remote string) []string { + return []string{"fossil", "clone", "--", remote, ".fossil"} + }, + fetch: []string{"fossil", "pull", "-R", ".fossil"}, + tags: func(remote string) []string { + return []string{"fossil", "tag", "-R", ".fossil", "list"} + }, + tagRE: re(`XXXTODO`), + statLocal: func(rev, remote string) []string { + return []string{"fossil", "info", "-R", ".fossil", rev} + }, + parseStat: fossilParseStat, + latest: "trunk", + readFile: func(rev, file, remote string) []string { + return []string{"fossil", "cat", "-R", ".fossil", "-r", rev, file} + }, + readZip: func(rev, subdir, remote, target string) []string { + extra := []string{} + if subdir != "" && !strings.ContainsAny(subdir, "*?[],") { + extra = []string{"--include", subdir} + } + // Note that vcsRepo.ReadZip below rewrites this command + // to run in a different directory, to work around a fossil bug. + return str.StringList("fossil", "zip", "-R", ".fossil", "--name", "prefix", extra, "--", rev, target) + }, + }, +} + +func (r *vcsRepo) loadTags() { + out, err := Run(r.dir, r.cmd.tags(r.remote)) + if err != nil { + return + } + + // Run tag-listing command and extract tags. + r.tags = make(map[string]bool) + for _, tag := range r.cmd.tagRE.FindAllString(string(out), -1) { + if r.cmd.badLocalRevRE != nil && r.cmd.badLocalRevRE.MatchString(tag) { + continue + } + r.tags[tag] = true + } +} + +func (r *vcsRepo) loadBranches() { + if r.cmd.branches == nil { + return + } + + out, err := Run(r.dir, r.cmd.branches(r.remote)) + if err != nil { + return + } + + r.branches = make(map[string]bool) + for _, branch := range r.cmd.branchRE.FindAllString(string(out), -1) { + if r.cmd.badLocalRevRE != nil && r.cmd.badLocalRevRE.MatchString(branch) { + continue + } + r.branches[branch] = true + } +} + +func (r *vcsRepo) Tags(prefix string) ([]string, error) { + unlock, err := r.mu.Lock() + if err != nil { + return nil, err + } + defer unlock() + + r.tagsOnce.Do(r.loadTags) + + tags := []string{} + for tag := range r.tags { + if strings.HasPrefix(tag, prefix) { + tags = append(tags, tag) + } + } + sort.Strings(tags) + return tags, nil +} + +func (r *vcsRepo) Stat(rev string) (*RevInfo, error) { + unlock, err := r.mu.Lock() + if err != nil { + return nil, err + } + defer unlock() + + if rev == "latest" { + rev = r.cmd.latest + } + r.branchesOnce.Do(r.loadBranches) + revOK := (r.cmd.badLocalRevRE == nil || !r.cmd.badLocalRevRE.MatchString(rev)) && !r.branches[rev] + if revOK { + if info, err := r.statLocal(rev); err == nil { + return info, nil + } + } + + r.fetchOnce.Do(r.fetch) + if r.fetchErr != nil { + return nil, r.fetchErr + } + info, err := r.statLocal(rev) + if err != nil { + return nil, err + } + if !revOK { + info.Version = info.Name + } + return info, nil +} + +func (r *vcsRepo) fetch() { + if len(r.cmd.fetch) > 0 { + _, r.fetchErr = Run(r.dir, r.cmd.fetch) + } +} + +func (r *vcsRepo) statLocal(rev string) (*RevInfo, error) { + out, err := Run(r.dir, r.cmd.statLocal(rev, r.remote)) + if err != nil { + return nil, &UnknownRevisionError{Rev: rev} + } + return r.cmd.parseStat(rev, string(out)) +} + +func (r *vcsRepo) Latest() (*RevInfo, error) { + return r.Stat("latest") +} + +func (r *vcsRepo) ReadFile(rev, file string, maxSize int64) ([]byte, error) { + if rev == "latest" { + rev = r.cmd.latest + } + _, err := r.Stat(rev) // download rev into local repo + if err != nil { + return nil, err + } + + // r.Stat acquires r.mu, so lock after that. + unlock, err := r.mu.Lock() + if err != nil { + return nil, err + } + defer unlock() + + out, err := Run(r.dir, r.cmd.readFile(rev, file, r.remote)) + if err != nil { + return nil, fs.ErrNotExist + } + return out, nil +} + +func (r *vcsRepo) ReadFileRevs(revs []string, file string, maxSize int64) (map[string]*FileRev, error) { + // We don't technically need to lock here since we're returning an error + // uncondititonally, but doing so anyway will help to avoid baking in + // lock-inversion bugs. + unlock, err := r.mu.Lock() + if err != nil { + return nil, err + } + defer unlock() + + return nil, vcsErrorf("ReadFileRevs not implemented") +} + +func (r *vcsRepo) RecentTag(rev, prefix string, allowed func(string) bool) (tag string, err error) { + // We don't technically need to lock here since we're returning an error + // uncondititonally, but doing so anyway will help to avoid baking in + // lock-inversion bugs. + unlock, err := r.mu.Lock() + if err != nil { + return "", err + } + defer unlock() + + return "", vcsErrorf("RecentTag not implemented") +} + +func (r *vcsRepo) DescendsFrom(rev, tag string) (bool, error) { + unlock, err := r.mu.Lock() + if err != nil { + return false, err + } + defer unlock() + + return false, vcsErrorf("DescendsFrom not implemented") +} + +func (r *vcsRepo) ReadZip(rev, subdir string, maxSize int64) (zip io.ReadCloser, err error) { + if r.cmd.readZip == nil && r.cmd.doReadZip == nil { + return nil, vcsErrorf("ReadZip not implemented for %s", r.cmd.vcs) + } + + unlock, err := r.mu.Lock() + if err != nil { + return nil, err + } + defer unlock() + + if rev == "latest" { + rev = r.cmd.latest + } + f, err := os.CreateTemp("", "go-readzip-*.zip") + if err != nil { + return nil, err + } + if r.cmd.doReadZip != nil { + lw := &limitedWriter{ + W: f, + N: maxSize, + ErrLimitReached: errors.New("ReadZip: encoded file exceeds allowed size"), + } + err = r.cmd.doReadZip(lw, r.dir, rev, subdir, r.remote) + if err == nil { + _, err = f.Seek(0, io.SeekStart) + } + } else if r.cmd.vcs == "fossil" { + // If you run + // fossil zip -R .fossil --name prefix trunk /tmp/x.zip + // fossil fails with "unable to create directory /tmp" [sic]. + // Change the command to run in /tmp instead, + // replacing the -R argument with an absolute path. + args := r.cmd.readZip(rev, subdir, r.remote, filepath.Base(f.Name())) + for i := range args { + if args[i] == ".fossil" { + args[i] = filepath.Join(r.dir, ".fossil") + } + } + _, err = Run(filepath.Dir(f.Name()), args) + } else { + _, err = Run(r.dir, r.cmd.readZip(rev, subdir, r.remote, f.Name())) + } + if err != nil { + f.Close() + os.Remove(f.Name()) + return nil, err + } + return &deleteCloser{f}, nil +} + +// deleteCloser is a file that gets deleted on Close. +type deleteCloser struct { + *os.File +} + +func (d *deleteCloser) Close() error { + defer os.Remove(d.File.Name()) + return d.File.Close() +} + +func hgParseStat(rev, out string) (*RevInfo, error) { + f := strings.Fields(string(out)) + if len(f) < 3 { + return nil, vcsErrorf("unexpected response from hg log: %q", out) + } + hash := f[0] + version := rev + if strings.HasPrefix(hash, version) { + version = hash // extend to full hash + } + t, err := strconv.ParseInt(f[1], 10, 64) + if err != nil { + return nil, vcsErrorf("invalid time from hg log: %q", out) + } + + var tags []string + for _, tag := range f[3:] { + if tag != "tip" { + tags = append(tags, tag) + } + } + sort.Strings(tags) + + info := &RevInfo{ + Name: hash, + Short: ShortenSHA1(hash), + Time: time.Unix(t, 0).UTC(), + Version: version, + Tags: tags, + } + return info, nil +} + +func bzrParseStat(rev, out string) (*RevInfo, error) { + var revno int64 + var tm time.Time + for _, line := range strings.Split(out, "\n") { + if line == "" || line[0] == ' ' || line[0] == '\t' { + // End of header, start of commit message. + break + } + if line[0] == '-' { + continue + } + i := strings.Index(line, ":") + if i < 0 { + // End of header, start of commit message. + break + } + key, val := line[:i], strings.TrimSpace(line[i+1:]) + switch key { + case "revno": + if j := strings.Index(val, " "); j >= 0 { + val = val[:j] + } + i, err := strconv.ParseInt(val, 10, 64) + if err != nil { + return nil, vcsErrorf("unexpected revno from bzr log: %q", line) + } + revno = i + case "timestamp": + j := strings.Index(val, " ") + if j < 0 { + return nil, vcsErrorf("unexpected timestamp from bzr log: %q", line) + } + t, err := time.Parse("2006-01-02 15:04:05 -0700", val[j+1:]) + if err != nil { + return nil, vcsErrorf("unexpected timestamp from bzr log: %q", line) + } + tm = t.UTC() + } + } + if revno == 0 || tm.IsZero() { + return nil, vcsErrorf("unexpected response from bzr log: %q", out) + } + + info := &RevInfo{ + Name: fmt.Sprintf("%d", revno), + Short: fmt.Sprintf("%012d", revno), + Time: tm, + Version: rev, + } + return info, nil +} + +func fossilParseStat(rev, out string) (*RevInfo, error) { + for _, line := range strings.Split(out, "\n") { + if strings.HasPrefix(line, "uuid:") || strings.HasPrefix(line, "hash:") { + f := strings.Fields(line) + if len(f) != 5 || len(f[1]) != 40 || f[4] != "UTC" { + return nil, vcsErrorf("unexpected response from fossil info: %q", line) + } + t, err := time.Parse("2006-01-02 15:04:05", f[2]+" "+f[3]) + if err != nil { + return nil, vcsErrorf("unexpected response from fossil info: %q", line) + } + hash := f[1] + version := rev + if strings.HasPrefix(hash, version) { + version = hash // extend to full hash + } + info := &RevInfo{ + Name: hash, + Short: ShortenSHA1(hash), + Time: t, + Version: version, + } + return info, nil + } + } + return nil, vcsErrorf("unexpected response from fossil info: %q", out) +} + +type limitedWriter struct { + W io.Writer + N int64 + ErrLimitReached error +} + +func (l *limitedWriter) Write(p []byte) (n int, err error) { + if l.N > 0 { + max := len(p) + if l.N < int64(max) { + max = int(l.N) + } + n, err = l.W.Write(p[:max]) + l.N -= int64(n) + if err != nil || n >= len(p) { + return n, err + } + } + + return n, l.ErrLimitReached +} |