| // 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 ( |
| "bytes" |
| "errors" |
| "fmt" |
| "io" |
| "io/fs" |
| "net/url" |
| "os" |
| "os/exec" |
| "path/filepath" |
| "sort" |
| "strconv" |
| "strings" |
| "sync" |
| "time" |
| |
| "cmd/go/internal/lockedfile" |
| "cmd/go/internal/par" |
| "cmd/go/internal/web" |
| |
| "golang.org/x/mod/semver" |
| ) |
| |
| // LocalGitRepo is like Repo but accepts both Git remote references |
| // and paths to repositories on the local file system. |
| func LocalGitRepo(remote string) (Repo, error) { |
| return newGitRepoCached(remote, true) |
| } |
| |
| // A notExistError wraps another error to retain its original text |
| // but makes it opaquely equivalent to fs.ErrNotExist. |
| type notExistError struct { |
| err error |
| } |
| |
| func (e notExistError) Error() string { return e.err.Error() } |
| func (notExistError) Is(err error) bool { return err == fs.ErrNotExist } |
| |
| const gitWorkDirType = "git3" |
| |
| var gitRepoCache par.Cache |
| |
| func newGitRepoCached(remote string, localOK bool) (Repo, error) { |
| type key struct { |
| remote string |
| localOK bool |
| } |
| type cached struct { |
| repo Repo |
| err error |
| } |
| |
| c := gitRepoCache.Do(key{remote, localOK}, func() interface{} { |
| repo, err := newGitRepo(remote, localOK) |
| return cached{repo, err} |
| }).(cached) |
| |
| return c.repo, c.err |
| } |
| |
| func newGitRepo(remote string, localOK bool) (Repo, error) { |
| r := &gitRepo{remote: remote} |
| if strings.Contains(remote, "://") { |
| // This is a remote path. |
| var err error |
| r.dir, r.mu.Path, err = WorkDir(gitWorkDirType, r.remote) |
| if err != nil { |
| return nil, err |
| } |
| |
| unlock, err := r.mu.Lock() |
| if err != nil { |
| return nil, err |
| } |
| defer unlock() |
| |
| if _, err := os.Stat(filepath.Join(r.dir, "objects")); err != nil { |
| if _, err := Run(r.dir, "git", "init", "--bare"); err != nil { |
| os.RemoveAll(r.dir) |
| return nil, err |
| } |
| // We could just say git fetch https://whatever later, |
| // but this lets us say git fetch origin instead, which |
| // is a little nicer. More importantly, using a named remote |
| // avoids a problem with Git LFS. See golang.org/issue/25605. |
| if _, err := Run(r.dir, "git", "remote", "add", "origin", "--", r.remote); err != nil { |
| os.RemoveAll(r.dir) |
| return nil, err |
| } |
| } |
| r.remoteURL = r.remote |
| r.remote = "origin" |
| } else { |
| // Local path. |
| // Disallow colon (not in ://) because sometimes |
| // that's rcp-style host:path syntax and sometimes it's not (c:\work). |
| // The go command has always insisted on URL syntax for ssh. |
| if strings.Contains(remote, ":") { |
| return nil, fmt.Errorf("git remote cannot use host:path syntax") |
| } |
| if !localOK { |
| return nil, fmt.Errorf("git remote must not be local directory") |
| } |
| r.local = true |
| info, err := os.Stat(remote) |
| if err != nil { |
| return nil, err |
| } |
| if !info.IsDir() { |
| return nil, fmt.Errorf("%s exists but is not a directory", remote) |
| } |
| r.dir = remote |
| r.mu.Path = r.dir + ".lock" |
| } |
| return r, nil |
| } |
| |
| type gitRepo struct { |
| remote, remoteURL string |
| local bool |
| dir string |
| |
| mu lockedfile.Mutex // protects fetchLevel and git repo state |
| |
| fetchLevel int |
| |
| statCache par.Cache |
| |
| refsOnce sync.Once |
| // refs maps branch and tag refs (e.g., "HEAD", "refs/heads/master") |
| // to commits (e.g., "37ffd2e798afde829a34e8955b716ab730b2a6d6") |
| refs map[string]string |
| refsErr error |
| |
| localTagsOnce sync.Once |
| localTags map[string]bool |
| } |
| |
| const ( |
| // How much have we fetched into the git repo (in this process)? |
| fetchNone = iota // nothing yet |
| fetchSome // shallow fetches of individual hashes |
| fetchAll // "fetch -t origin": get all remote branches and tags |
| ) |
| |
| // loadLocalTags loads tag references from the local git cache |
| // into the map r.localTags. |
| // Should only be called as r.localTagsOnce.Do(r.loadLocalTags). |
| func (r *gitRepo) loadLocalTags() { |
| // The git protocol sends all known refs and ls-remote filters them on the client side, |
| // so we might as well record both heads and tags in one shot. |
| // Most of the time we only care about tags but sometimes we care about heads too. |
| out, err := Run(r.dir, "git", "tag", "-l") |
| if err != nil { |
| return |
| } |
| |
| r.localTags = make(map[string]bool) |
| for _, line := range strings.Split(string(out), "\n") { |
| if line != "" { |
| r.localTags[line] = true |
| } |
| } |
| } |
| |
| // loadRefs loads heads and tags references from the remote into the map r.refs. |
| // Should only be called as r.refsOnce.Do(r.loadRefs). |
| func (r *gitRepo) loadRefs() { |
| // The git protocol sends all known refs and ls-remote filters them on the client side, |
| // so we might as well record both heads and tags in one shot. |
| // Most of the time we only care about tags but sometimes we care about heads too. |
| out, gitErr := Run(r.dir, "git", "ls-remote", "-q", r.remote) |
| if gitErr != nil { |
| if rerr, ok := gitErr.(*RunError); ok { |
| if bytes.Contains(rerr.Stderr, []byte("fatal: could not read Username")) { |
| rerr.HelpText = "Confirm the import path was entered correctly.\nIf this is a private repository, see https://golang.org/doc/faq#git_https for additional information." |
| } |
| } |
| |
| // If the remote URL doesn't exist at all, ideally we should treat the whole |
| // repository as nonexistent by wrapping the error in a notExistError. |
| // For HTTP and HTTPS, that's easy to detect: we'll try to fetch the URL |
| // ourselves and see what code it serves. |
| if u, err := url.Parse(r.remoteURL); err == nil && (u.Scheme == "http" || u.Scheme == "https") { |
| if _, err := web.GetBytes(u); errors.Is(err, fs.ErrNotExist) { |
| gitErr = notExistError{gitErr} |
| } |
| } |
| |
| r.refsErr = gitErr |
| return |
| } |
| |
| r.refs = make(map[string]string) |
| for _, line := range strings.Split(string(out), "\n") { |
| f := strings.Fields(line) |
| if len(f) != 2 { |
| continue |
| } |
| if f[1] == "HEAD" || strings.HasPrefix(f[1], "refs/heads/") || strings.HasPrefix(f[1], "refs/tags/") { |
| r.refs[f[1]] = f[0] |
| } |
| } |
| for ref, hash := range r.refs { |
| if strings.HasSuffix(ref, "^{}") { // record unwrapped annotated tag as value of tag |
| r.refs[strings.TrimSuffix(ref, "^{}")] = hash |
| delete(r.refs, ref) |
| } |
| } |
| } |
| |
| func (r *gitRepo) Tags(prefix string) ([]string, error) { |
| r.refsOnce.Do(r.loadRefs) |
| if r.refsErr != nil { |
| return nil, r.refsErr |
| } |
| |
| tags := []string{} |
| for ref := range r.refs { |
| if !strings.HasPrefix(ref, "refs/tags/") { |
| continue |
| } |
| tag := ref[len("refs/tags/"):] |
| if !strings.HasPrefix(tag, prefix) { |
| continue |
| } |
| tags = append(tags, tag) |
| } |
| sort.Strings(tags) |
| return tags, nil |
| } |
| |
| func (r *gitRepo) Latest() (*RevInfo, error) { |
| r.refsOnce.Do(r.loadRefs) |
| if r.refsErr != nil { |
| return nil, r.refsErr |
| } |
| if r.refs["HEAD"] == "" { |
| return nil, ErrNoCommits |
| } |
| return r.Stat(r.refs["HEAD"]) |
| } |
| |
| // findRef finds some ref name for the given hash, |
| // for use when the server requires giving a ref instead of a hash. |
| // There may be multiple ref names for a given hash, |
| // in which case this returns some name - it doesn't matter which. |
| func (r *gitRepo) findRef(hash string) (ref string, ok bool) { |
| r.refsOnce.Do(r.loadRefs) |
| for ref, h := range r.refs { |
| if h == hash { |
| return ref, true |
| } |
| } |
| return "", false |
| } |
| |
| // minHashDigits is the minimum number of digits to require |
| // before accepting a hex digit sequence as potentially identifying |
| // a specific commit in a git repo. (Of course, users can always |
| // specify more digits, and many will paste in all 40 digits, |
| // but many of git's commands default to printing short hashes |
| // as 7 digits.) |
| const minHashDigits = 7 |
| |
| // stat stats the given rev in the local repository, |
| // or else it fetches more info from the remote repository and tries again. |
| func (r *gitRepo) stat(rev string) (*RevInfo, error) { |
| if r.local { |
| return r.statLocal(rev, rev) |
| } |
| |
| // Fast path: maybe rev is a hash we already have locally. |
| didStatLocal := false |
| if len(rev) >= minHashDigits && len(rev) <= 40 && AllHex(rev) { |
| if info, err := r.statLocal(rev, rev); err == nil { |
| return info, nil |
| } |
| didStatLocal = true |
| } |
| |
| // Maybe rev is a tag we already have locally. |
| // (Note that we're excluding branches, which can be stale.) |
| r.localTagsOnce.Do(r.loadLocalTags) |
| if r.localTags[rev] { |
| return r.statLocal(rev, "refs/tags/"+rev) |
| } |
| |
| // Maybe rev is the name of a tag or branch on the remote server. |
| // Or maybe it's the prefix of a hash of a named ref. |
| // Try to resolve to both a ref (git name) and full (40-hex-digit) commit hash. |
| r.refsOnce.Do(r.loadRefs) |
| var ref, hash string |
| if r.refs["refs/tags/"+rev] != "" { |
| ref = "refs/tags/" + rev |
| hash = r.refs[ref] |
| // Keep rev as is: tags are assumed not to change meaning. |
| } else if r.refs["refs/heads/"+rev] != "" { |
| ref = "refs/heads/" + rev |
| hash = r.refs[ref] |
| rev = hash // Replace rev, because meaning of refs/heads/foo can change. |
| } else if rev == "HEAD" && r.refs["HEAD"] != "" { |
| ref = "HEAD" |
| hash = r.refs[ref] |
| rev = hash // Replace rev, because meaning of HEAD can change. |
| } else if len(rev) >= minHashDigits && len(rev) <= 40 && AllHex(rev) { |
| // At the least, we have a hash prefix we can look up after the fetch below. |
| // Maybe we can map it to a full hash using the known refs. |
| prefix := rev |
| // Check whether rev is prefix of known ref hash. |
| for k, h := range r.refs { |
| if strings.HasPrefix(h, prefix) { |
| if hash != "" && hash != h { |
| // Hash is an ambiguous hash prefix. |
| // More information will not change that. |
| return nil, fmt.Errorf("ambiguous revision %s", rev) |
| } |
| if ref == "" || ref > k { // Break ties deterministically when multiple refs point at same hash. |
| ref = k |
| } |
| rev = h |
| hash = h |
| } |
| } |
| if hash == "" && len(rev) == 40 { // Didn't find a ref, but rev is a full hash. |
| hash = rev |
| } |
| } else { |
| return nil, &UnknownRevisionError{Rev: rev} |
| } |
| |
| // Protect r.fetchLevel and the "fetch more and more" sequence. |
| unlock, err := r.mu.Lock() |
| if err != nil { |
| return nil, err |
| } |
| defer unlock() |
| |
| // Perhaps r.localTags did not have the ref when we loaded local tags, |
| // but we've since done fetches that pulled down the hash we need |
| // (or already have the hash we need, just without its tag). |
| // Either way, try a local stat before falling back to network I/O. |
| if !didStatLocal { |
| if info, err := r.statLocal(rev, hash); err == nil { |
| if strings.HasPrefix(ref, "refs/tags/") { |
| // Make sure tag exists, so it will be in localTags next time the go command is run. |
| Run(r.dir, "git", "tag", strings.TrimPrefix(ref, "refs/tags/"), hash) |
| } |
| return info, nil |
| } |
| } |
| |
| // If we know a specific commit we need and its ref, fetch it. |
| // We do NOT fetch arbitrary hashes (when we don't know the ref) |
| // because we want to avoid ever importing a commit that isn't |
| // reachable from refs/tags/* or refs/heads/* or HEAD. |
| // Both Gerrit and GitHub expose every CL/PR as a named ref, |
| // and we don't want those commits masquerading as being real |
| // pseudo-versions in the main repo. |
| if r.fetchLevel <= fetchSome && ref != "" && hash != "" && !r.local { |
| r.fetchLevel = fetchSome |
| var refspec string |
| if ref != "" && ref != "HEAD" { |
| // If we do know the ref name, save the mapping locally |
| // so that (if it is a tag) it can show up in localTags |
| // on a future call. Also, some servers refuse to allow |
| // full hashes in ref specs, so prefer a ref name if known. |
| refspec = ref + ":" + ref |
| } else { |
| // Fetch the hash but give it a local name (refs/dummy), |
| // because that triggers the fetch behavior of creating any |
| // other known remote tags for the hash. We never use |
| // refs/dummy (it's not refs/tags/dummy) and it will be |
| // overwritten in the next command, and that's fine. |
| ref = hash |
| refspec = hash + ":refs/dummy" |
| } |
| _, err := Run(r.dir, "git", "fetch", "-f", "--depth=1", r.remote, refspec) |
| if err == nil { |
| return r.statLocal(rev, ref) |
| } |
| // Don't try to be smart about parsing the error. |
| // It's too complex and varies too much by git version. |
| // No matter what went wrong, fall back to a complete fetch. |
| } |
| |
| // Last resort. |
| // Fetch all heads and tags and hope the hash we want is in the history. |
| if err := r.fetchRefsLocked(); err != nil { |
| return nil, err |
| } |
| |
| return r.statLocal(rev, rev) |
| } |
| |
| // fetchRefsLocked fetches all heads and tags from the origin, along with the |
| // ancestors of those commits. |
| // |
| // We only fetch heads and tags, not arbitrary other commits: we don't want to |
| // pull in off-branch commits (such as rejected GitHub pull requests) that the |
| // server may be willing to provide. (See the comments within the stat method |
| // for more detail.) |
| // |
| // fetchRefsLocked requires that r.mu remain locked for the duration of the call. |
| func (r *gitRepo) fetchRefsLocked() error { |
| if r.fetchLevel < fetchAll { |
| // NOTE: To work around a bug affecting Git clients up to at least 2.23.0 |
| // (2019-08-16), we must first expand the set of local refs, and only then |
| // unshallow the repository as a separate fetch operation. (See |
| // golang.org/issue/34266 and |
| // https://github.com/git/git/blob/4c86140027f4a0d2caaa3ab4bd8bfc5ce3c11c8a/transport.c#L1303-L1309.) |
| |
| if _, err := Run(r.dir, "git", "fetch", "-f", r.remote, "refs/heads/*:refs/heads/*", "refs/tags/*:refs/tags/*"); err != nil { |
| return err |
| } |
| |
| if _, err := os.Stat(filepath.Join(r.dir, "shallow")); err == nil { |
| if _, err := Run(r.dir, "git", "fetch", "--unshallow", "-f", r.remote); err != nil { |
| return err |
| } |
| } |
| |
| r.fetchLevel = fetchAll |
| } |
| return nil |
| } |
| |
| // statLocal returns a RevInfo describing rev in the local git repository. |
| // It uses version as info.Version. |
| func (r *gitRepo) statLocal(version, rev string) (*RevInfo, error) { |
| out, err := Run(r.dir, "git", "-c", "log.showsignature=false", "log", "-n1", "--format=format:%H %ct %D", rev, "--") |
| if err != nil { |
| return nil, &UnknownRevisionError{Rev: rev} |
| } |
| f := strings.Fields(string(out)) |
| if len(f) < 2 { |
| return nil, fmt.Errorf("unexpected response from git log: %q", out) |
| } |
| hash := f[0] |
| if strings.HasPrefix(hash, version) { |
| version = hash // extend to full hash |
| } |
| t, err := strconv.ParseInt(f[1], 10, 64) |
| if err != nil { |
| return nil, fmt.Errorf("invalid time from git log: %q", out) |
| } |
| |
| info := &RevInfo{ |
| Name: hash, |
| Short: ShortenSHA1(hash), |
| Time: time.Unix(t, 0).UTC(), |
| Version: hash, |
| } |
| |
| // Add tags. Output looks like: |
| // ede458df7cd0fdca520df19a33158086a8a68e81 1523994202 HEAD -> master, tag: v1.2.4-annotated, tag: v1.2.3, origin/master, origin/HEAD |
| for i := 2; i < len(f); i++ { |
| if f[i] == "tag:" { |
| i++ |
| if i < len(f) { |
| info.Tags = append(info.Tags, strings.TrimSuffix(f[i], ",")) |
| } |
| } |
| } |
| sort.Strings(info.Tags) |
| |
| // Used hash as info.Version above. |
| // Use caller's suggested version if it appears in the tag list |
| // (filters out branch names, HEAD). |
| for _, tag := range info.Tags { |
| if version == tag { |
| info.Version = version |
| } |
| } |
| |
| return info, nil |
| } |
| |
| func (r *gitRepo) Stat(rev string) (*RevInfo, error) { |
| if rev == "latest" { |
| return r.Latest() |
| } |
| type cached struct { |
| info *RevInfo |
| err error |
| } |
| c := r.statCache.Do(rev, func() interface{} { |
| info, err := r.stat(rev) |
| return cached{info, err} |
| }).(cached) |
| return c.info, c.err |
| } |
| |
| func (r *gitRepo) ReadFile(rev, file string, maxSize int64) ([]byte, error) { |
| // TODO: Could use git cat-file --batch. |
| info, err := r.Stat(rev) // download rev into local git repo |
| if err != nil { |
| return nil, err |
| } |
| out, err := Run(r.dir, "git", "cat-file", "blob", info.Name+":"+file) |
| if err != nil { |
| return nil, fs.ErrNotExist |
| } |
| return out, nil |
| } |
| |
| func (r *gitRepo) ReadFileRevs(revs []string, file string, maxSize int64) (map[string]*FileRev, error) { |
| // Create space to hold results. |
| files := make(map[string]*FileRev) |
| for _, rev := range revs { |
| f := &FileRev{Rev: rev} |
| files[rev] = f |
| } |
| |
| // Collect locally-known revs. |
| need, err := r.readFileRevs(revs, file, files) |
| if err != nil { |
| return nil, err |
| } |
| if len(need) == 0 { |
| return files, nil |
| } |
| |
| // Build list of known remote refs that might help. |
| var redo []string |
| r.refsOnce.Do(r.loadRefs) |
| if r.refsErr != nil { |
| return nil, r.refsErr |
| } |
| for _, tag := range need { |
| if r.refs["refs/tags/"+tag] != "" { |
| redo = append(redo, tag) |
| } |
| } |
| if len(redo) == 0 { |
| return files, nil |
| } |
| |
| // Protect r.fetchLevel and the "fetch more and more" sequence. |
| // See stat method above. |
| unlock, err := r.mu.Lock() |
| if err != nil { |
| return nil, err |
| } |
| defer unlock() |
| |
| if err := r.fetchRefsLocked(); err != nil { |
| return nil, err |
| } |
| |
| if _, err := r.readFileRevs(redo, file, files); err != nil { |
| return nil, err |
| } |
| |
| return files, nil |
| } |
| |
| func (r *gitRepo) readFileRevs(tags []string, file string, fileMap map[string]*FileRev) (missing []string, err error) { |
| var stdin bytes.Buffer |
| for _, tag := range tags { |
| fmt.Fprintf(&stdin, "refs/tags/%s\n", tag) |
| fmt.Fprintf(&stdin, "refs/tags/%s:%s\n", tag, file) |
| } |
| |
| data, err := RunWithStdin(r.dir, &stdin, "git", "cat-file", "--batch") |
| if err != nil { |
| return nil, err |
| } |
| |
| next := func() (typ string, body []byte, ok bool) { |
| var line string |
| i := bytes.IndexByte(data, '\n') |
| if i < 0 { |
| return "", nil, false |
| } |
| line, data = string(bytes.TrimSpace(data[:i])), data[i+1:] |
| if strings.HasSuffix(line, " missing") { |
| return "missing", nil, true |
| } |
| f := strings.Fields(line) |
| if len(f) != 3 { |
| return "", nil, false |
| } |
| n, err := strconv.Atoi(f[2]) |
| if err != nil || n > len(data) { |
| return "", nil, false |
| } |
| body, data = data[:n], data[n:] |
| if len(data) > 0 && data[0] == '\r' { |
| data = data[1:] |
| } |
| if len(data) > 0 && data[0] == '\n' { |
| data = data[1:] |
| } |
| return f[1], body, true |
| } |
| |
| badGit := func() ([]string, error) { |
| return nil, fmt.Errorf("malformed output from git cat-file --batch") |
| } |
| |
| for _, tag := range tags { |
| commitType, _, ok := next() |
| if !ok { |
| return badGit() |
| } |
| fileType, fileData, ok := next() |
| if !ok { |
| return badGit() |
| } |
| f := fileMap[tag] |
| f.Data = nil |
| f.Err = nil |
| switch commitType { |
| default: |
| f.Err = fmt.Errorf("unexpected non-commit type %q for rev %s", commitType, tag) |
| |
| case "missing": |
| // Note: f.Err must not satisfy os.IsNotExist. That's reserved for the file not existing in a valid commit. |
| f.Err = fmt.Errorf("no such rev %s", tag) |
| missing = append(missing, tag) |
| |
| case "tag", "commit": |
| switch fileType { |
| default: |
| f.Err = &fs.PathError{Path: tag + ":" + file, Op: "read", Err: fmt.Errorf("unexpected non-blob type %q", fileType)} |
| case "missing": |
| f.Err = &fs.PathError{Path: tag + ":" + file, Op: "read", Err: fs.ErrNotExist} |
| case "blob": |
| f.Data = fileData |
| } |
| } |
| } |
| if len(bytes.TrimSpace(data)) != 0 { |
| return badGit() |
| } |
| |
| return missing, nil |
| } |
| |
| func (r *gitRepo) RecentTag(rev, prefix string, allowed func(string) bool) (tag string, err error) { |
| info, err := r.Stat(rev) |
| if err != nil { |
| return "", err |
| } |
| rev = info.Name // expand hash prefixes |
| |
| // describe sets tag and err using 'git for-each-ref' and reports whether the |
| // result is definitive. |
| describe := func() (definitive bool) { |
| var out []byte |
| out, err = Run(r.dir, "git", "for-each-ref", "--format", "%(refname)", "refs/tags", "--merged", rev) |
| if err != nil { |
| return true |
| } |
| |
| // prefixed tags aren't valid semver tags so compare without prefix, but only tags with correct prefix |
| var highest string |
| for _, line := range strings.Split(string(out), "\n") { |
| line = strings.TrimSpace(line) |
| // git do support lstrip in for-each-ref format, but it was added in v2.13.0. Stripping here |
| // instead gives support for git v2.7.0. |
| if !strings.HasPrefix(line, "refs/tags/") { |
| continue |
| } |
| line = line[len("refs/tags/"):] |
| |
| if !strings.HasPrefix(line, prefix) { |
| continue |
| } |
| |
| semtag := line[len(prefix):] |
| // Consider only tags that are valid and complete (not just major.minor prefixes). |
| // NOTE: Do not replace the call to semver.Compare with semver.Max. |
| // We want to return the actual tag, not a canonicalized version of it, |
| // and semver.Max currently canonicalizes (see golang.org/issue/32700). |
| if c := semver.Canonical(semtag); c == "" || !strings.HasPrefix(semtag, c) || !allowed(semtag) { |
| continue |
| } |
| if semver.Compare(semtag, highest) > 0 { |
| highest = semtag |
| } |
| } |
| |
| if highest != "" { |
| tag = prefix + highest |
| } |
| |
| return tag != "" && !AllHex(tag) |
| } |
| |
| if describe() { |
| return tag, err |
| } |
| |
| // Git didn't find a version tag preceding the requested rev. |
| // See whether any plausible tag exists. |
| tags, err := r.Tags(prefix + "v") |
| if err != nil { |
| return "", err |
| } |
| if len(tags) == 0 { |
| return "", nil |
| } |
| |
| // There are plausible tags, but we don't know if rev is a descendent of any of them. |
| // Fetch the history to find out. |
| |
| unlock, err := r.mu.Lock() |
| if err != nil { |
| return "", err |
| } |
| defer unlock() |
| |
| if err := r.fetchRefsLocked(); err != nil { |
| return "", err |
| } |
| |
| // If we've reached this point, we have all of the commits that are reachable |
| // from all heads and tags. |
| // |
| // The only refs we should be missing are those that are no longer reachable |
| // (or never were reachable) from any branch or tag, including the master |
| // branch, and we don't want to resolve them anyway (they're probably |
| // unreachable for a reason). |
| // |
| // Try one last time in case some other goroutine fetched rev while we were |
| // waiting on the lock. |
| describe() |
| return tag, err |
| } |
| |
| func (r *gitRepo) DescendsFrom(rev, tag string) (bool, error) { |
| // The "--is-ancestor" flag was added to "git merge-base" in version 1.8.0, so |
| // this won't work with Git 1.7.1. According to golang.org/issue/28550, cmd/go |
| // already doesn't work with Git 1.7.1, so at least it's not a regression. |
| // |
| // git merge-base --is-ancestor exits with status 0 if rev is an ancestor, or |
| // 1 if not. |
| _, err := Run(r.dir, "git", "merge-base", "--is-ancestor", "--", tag, rev) |
| |
| // Git reports "is an ancestor" with exit code 0 and "not an ancestor" with |
| // exit code 1. |
| // Unfortunately, if we've already fetched rev with a shallow history, git |
| // merge-base has been observed to report a false-negative, so don't stop yet |
| // even if the exit code is 1! |
| if err == nil { |
| return true, nil |
| } |
| |
| // See whether the tag and rev even exist. |
| tags, err := r.Tags(tag) |
| if err != nil { |
| return false, err |
| } |
| if len(tags) == 0 { |
| return false, nil |
| } |
| |
| // NOTE: r.stat is very careful not to fetch commits that we shouldn't know |
| // about, like rejected GitHub pull requests, so don't try to short-circuit |
| // that here. |
| if _, err = r.stat(rev); err != nil { |
| return false, err |
| } |
| |
| // Now fetch history so that git can search for a path. |
| unlock, err := r.mu.Lock() |
| if err != nil { |
| return false, err |
| } |
| defer unlock() |
| |
| if r.fetchLevel < fetchAll { |
| // Fetch the complete history for all refs and heads. It would be more |
| // efficient to only fetch the history from rev to tag, but that's much more |
| // complicated, and any kind of shallow fetch is fairly likely to trigger |
| // bugs in JGit servers and/or the go command anyway. |
| if err := r.fetchRefsLocked(); err != nil { |
| return false, err |
| } |
| } |
| |
| _, err = Run(r.dir, "git", "merge-base", "--is-ancestor", "--", tag, rev) |
| if err == nil { |
| return true, nil |
| } |
| if ee, ok := err.(*RunError).Err.(*exec.ExitError); ok && ee.ExitCode() == 1 { |
| return false, nil |
| } |
| return false, err |
| } |
| |
| func (r *gitRepo) ReadZip(rev, subdir string, maxSize int64) (zip io.ReadCloser, err error) { |
| // TODO: Use maxSize or drop it. |
| args := []string{} |
| if subdir != "" { |
| args = append(args, "--", subdir) |
| } |
| info, err := r.Stat(rev) // download rev into local git repo |
| if err != nil { |
| return nil, err |
| } |
| |
| unlock, err := r.mu.Lock() |
| if err != nil { |
| return nil, err |
| } |
| defer unlock() |
| |
| if err := ensureGitAttributes(r.dir); err != nil { |
| return nil, err |
| } |
| |
| // Incredibly, git produces different archives depending on whether |
| // it is running on a Windows system or not, in an attempt to normalize |
| // text file line endings. Setting -c core.autocrlf=input means only |
| // translate files on the way into the repo, not on the way out (archive). |
| // The -c core.eol=lf should be unnecessary but set it anyway. |
| archive, err := Run(r.dir, "git", "-c", "core.autocrlf=input", "-c", "core.eol=lf", "archive", "--format=zip", "--prefix=prefix/", info.Name, args) |
| if err != nil { |
| if bytes.Contains(err.(*RunError).Stderr, []byte("did not match any files")) { |
| return nil, fs.ErrNotExist |
| } |
| return nil, err |
| } |
| |
| return io.NopCloser(bytes.NewReader(archive)), nil |
| } |
| |
| // ensureGitAttributes makes sure export-subst and export-ignore features are |
| // disabled for this repo. This is intended to be run prior to running git |
| // archive so that zip files are generated that produce consistent ziphashes |
| // for a given revision, independent of variables such as git version and the |
| // size of the repo. |
| // |
| // See: https://github.com/golang/go/issues/27153 |
| func ensureGitAttributes(repoDir string) (err error) { |
| const attr = "\n* -export-subst -export-ignore\n" |
| |
| d := repoDir + "/info" |
| p := d + "/attributes" |
| |
| if err := os.MkdirAll(d, 0755); err != nil { |
| return err |
| } |
| |
| f, err := os.OpenFile(p, os.O_CREATE|os.O_APPEND|os.O_RDWR, 0666) |
| if err != nil { |
| return err |
| } |
| defer func() { |
| closeErr := f.Close() |
| if closeErr != nil { |
| err = closeErr |
| } |
| }() |
| |
| b, err := io.ReadAll(f) |
| if err != nil { |
| return err |
| } |
| if !bytes.HasSuffix(b, []byte(attr)) { |
| _, err := f.WriteString(attr) |
| return err |
| } |
| |
| return nil |
| } |