// Package repository contains helper methods for working with the Git repo.
package repository
import (
"bytes"
"crypto/sha1"
"fmt"
"io"
"os"
"os/exec"
"strings"
)
const branchRefPrefix = "refs/heads/"
// GitRepo represents an instance of a (local) git repository.
type GitRepo struct {
Path string
}
// Run the given git command with the given I/O reader/writers, returning an error if it fails.
func (repo *GitRepo) runGitCommandWithIO(stdin io.Reader, stdout, stderr io.Writer, args ...string) error {
cmd := exec.Command("git", args...)
cmd.Dir = repo.Path
cmd.Stdin = stdin
cmd.Stdout = stdout
cmd.Stderr = stderr
return cmd.Run()
}
// Run the given git command and return its stdout, or an error if the command fails.
func (repo *GitRepo) runGitCommandRaw(args ...string) (string, string, error) {
var stdout bytes.Buffer
var stderr bytes.Buffer
err := repo.runGitCommandWithIO(nil, &stdout, &stderr, args...)
return strings.TrimSpace(stdout.String()), strings.TrimSpace(stderr.String()), err
}
// Run the given git command and return its stdout, or an error if the command fails.
func (repo *GitRepo) runGitCommand(args ...string) (string, error) {
stdout, stderr, err := repo.runGitCommandRaw(args...)
if err != nil {
if stderr == "" {
stderr = "Error running git command: " + strings.Join(args, " ")
}
err = fmt.Errorf(stderr)
}
return stdout, err
}
// Run the given git command using the same stdin, stdout, and stderr as the review tool.
func (repo *GitRepo) runGitCommandInline(args ...string) error {
return repo.runGitCommandWithIO(os.Stdin, os.Stdout, os.Stderr, args...)
}
// NewGitRepo determines if the given working directory is inside of a git repository,
// and returns the corresponding GitRepo instance if it is.
func NewGitRepo(path string) (*GitRepo, error) {
repo := &GitRepo{Path: path}
_, _, err := repo.runGitCommandRaw("rev-parse")
if err == nil {
return repo, nil
}
if _, ok := err.(*exec.ExitError); ok {
return nil, err
}
return nil, err
}
// GetPath returns the path to the repo.
func (repo *GitRepo) GetPath() string {
return repo.Path
}
// GetRepoStateHash returns a hash which embodies the entire current state of a repository.
func (repo *GitRepo) GetRepoStateHash() (string, error) {
stateSummary, err := repo.runGitCommand("show-ref")
return fmt.Sprintf("%x", sha1.Sum([]byte(stateSummary))), err
}
// GetUserName returns the name the the user has used to configure git
func (repo *GitRepo) GetUserName() (string, error) {
return repo.runGitCommand("config", "user.name")
}
// GetUserEmail returns the email address that the user has used to configure git.
func (repo *GitRepo) GetUserEmail() (string, error) {
return repo.runGitCommand("config", "user.email")
}
// GetCoreEditor returns the name of the editor that the user has used to configure git.
func (repo *GitRepo) GetCoreEditor() (string, error) {
return repo.runGitCommand("var", "GIT_EDITOR")
}
// PullRefs pull git refs from a remote
func (repo *GitRepo) PullRefs(remote string, refPattern string) error {
fetchRefSpec := fmt.Sprintf("+%s:%s", refPattern, refPattern)
err := repo.runGitCommandInline("fetch", remote, fetchRefSpec)
// TODO: merge new data
return err
}
// PushRefs push git refs to a remote
func (repo *GitRepo) PushRefs(remote string, refPattern string) error {
// The push is liable to fail if the user forgot to do a pull first, so
// we treat errors as user errors rather than fatal errors.
err := repo.runGitCommandInline("push", remote, refPattern)
if err != nil {
return fmt.Errorf("failed to push to the remote '%s': %v", remote, err)
}
return nil
}
/*
//
//// GetSubmitStrategy returns the way in which a review is submitted
//func (repo *GitRepo) GetSubmitStrategy() (string, error) {
// submitStrategy, _ := repo.runGitCommand("config", "appraise.submit")
// return submitStrategy, nil
//}
//
//// HasUncommittedChanges returns true if there are local, uncommitted changes.
//func (repo *GitRepo) HasUncommittedChanges() (bool, error) {
// out, err := repo.runGitCommand("status", "--porcelain")
// if err != nil {
// return false, err
// }
// if len(out) > 0 {
// return true, nil
// }
// return false, nil
//}
//
//// VerifyCommit verifies that the supplied hash points to a known commit.
//func (repo *GitRepo) VerifyCommit(hash string) error {
// out, err := repo.runGitCommand("cat-file", "-t", hash)
// if err != nil {
// return err
// }
// objectType := strings.TrimSpace(string(out))
// if objectType != "commit" {
// return fmt.Errorf("Hash %q points to a non-commit object of type %q", hash, objectType)
// }
// return nil
//}
//
//// VerifyGitRef verifies that the supplied ref points to a known commit.
//func (repo *GitRepo) VerifyGitRef(ref string) error {
// _, err := repo.runGitCommand("show-ref", "--verify", ref)
// return err
//}
//
//// GetHeadRef returns the ref that is the current HEAD.
//func (repo *GitRepo) GetHeadRef() (string, error) {
// return repo.runGitCommand("symbolic-ref", "HEAD")
//}
//
//// GetCommitHash returns the hash of the commit pointed to by the given ref.
//func (repo *GitRepo) GetCommitHash(ref string) (string, error) {
// return repo.runGitCommand("show", "-s", "--format=%H", ref)
//}
//
//// ResolveRefCommit returns the commit pointed to by the given ref, which may be a remote ref.
////
//// This differs from GetCommitHash which only works on exact matches, in that it will try to
//// intelligently handle the scenario of a ref not existing locally, but being known to exist
//// in a remote repo.
////
//// This method should be used when a command may be performed by either the reviewer or the
//// reviewee, while GetCommitHash should be used when the encompassing command should only be
//// performed by the reviewee.
//func (repo *GitRepo) ResolveRefCommit(ref string) (string, error) {
// if err := repo.VerifyGitRef(ref); err == nil {
// return repo.GetCommitHash(ref)
// }
// if strings.HasPrefix(ref, "refs/heads/") {
// // The ref is a branch. Check if it exists in exactly one remote
// pattern := strings.Replace(ref, "refs/heads", "**", 1)
// matchingOutput, err := repo.runGitCommand("for-each-ref", "--format=%(refname)", pattern)
// if err != nil {
// return "", err
// }
// matchingRefs := strings.Split(matchingOutput, "\n")
// if len(matchingRefs) == 1 && matchingRefs[0] != "" {
// // There is exactly one match
// return repo.GetCommitHash(matchingRefs[0])
// }
// return "", fmt.Errorf("Unable to find a git ref matching the pattern %q", pattern)
// }
// return "", fmt.Errorf("Unknown git ref %q", ref)
//}
//
//// GetCommitMessage returns the message stored in the commit pointed to by the given ref.
//func (repo *GitRepo) GetCommitMessage(ref string) (string, error) {
// return repo.runGitCommand("show", "-s", "--format=%B", ref)
//}
//
//// GetCommitTime returns the commit time of the commit pointed to by the given ref.
//func (repo *GitRepo) GetCommitTime(ref string) (string, error) {
// return repo.runGitCommand("show", "-s", "--format=%ct", ref)
//}
//
//// GetLastParent returns the last parent of the given commit (as ordered by git).
//func (repo *GitRepo) GetLastParent(ref string) (string, error) {
// return repo.runGitCommand("rev-list", "--skip", "1", "-n", "1", ref)
//}
//
//// GetCommitDetails returns the details of a commit's metadata.
//func (repo GitRepo) GetCommitDetails(ref string) (*CommitDetails, error) {
// var err error
// show := func(formatString string) (result string) {
// if err != nil {
// return ""
// }
// result, err = repo.runGitCommand("show", "-s", ref, fmt.Sprintf("--format=tformat:%s", formatString))
// return result
// }
//
// jsonFormatString := "{\"tree\":\"%T\", \"time\": \"%at\"}"
// detailsJSON := show(jsonFormatString)
// if err != nil {
// return nil, err
// }
// var details CommitDetails
// err = json.Unmarshal([]byte(detailsJSON), &details)
// if err != nil {
// return nil, err
// }
// details.Author = show("%an")
// details.AuthorEmail = show("%ae")
// details.Summary = show("%s")
// parentsString := show("%P")
// details.Parents = strings.Split(parentsString, " ")
// if err != nil {
// return nil, err
// }
// return &details, nil
//}
//
//// MergeBase determines if the first commit that is an ancestor of the two arguments.
//func (repo *GitRepo) MergeBase(a, b string) (string, error) {
// return repo.runGitCommand("merge-base", a, b)
//}
//
//// IsAncestor determines if the first argument points to a commit that is an ancestor of the second.
//func (repo *GitRepo) IsAncestor(ancestor, descendant string) (bool, error) {
// _, _, err := repo.runGitCommandRaw("merge-base", "--is-ancestor", ancestor, descendant)
// if err == nil {
// return true, nil
// }
// if _, ok := err.(*exec.ExitError); ok {
// return false, nil
// }
// return false, fmt.Errorf("Error while trying to determine commit ancestry: %v", err)
//}
//
//// Diff computes the diff between two given commits.
//func (repo *GitRepo) Diff(left, right string, diffArgs ...string) (string, error) {
// args := []string{"diff"}
// args = append(args, diffArgs...)
// args = append(args, fmt.Sprintf("%s..%s", left, right))
// return repo.runGitCommand(args...)
//}
//
//// Show returns the contents of the given file at the given commit.
//func (repo *GitRepo) Show(commit, path string) (string, error) {
// return repo.runGitCommand("show", fmt.Sprintf("%s:%s", commit, path))
//}
//
//// SwitchToRef changes the currently-checked-out ref.
//func (repo *GitRepo) SwitchToRef(ref string) error {
// // If the ref starts with "refs/heads/", then we have to trim that prefix,
// // or else we will wind up in a detached HEAD state.
// if strings.HasPrefix(ref, branchRefPrefix) {
// ref = ref[len(branchRefPrefix):]
// }
// _, err := repo.runGitCommand("checkout", ref)
// return err
//}
//
//// mergeArchives merges two archive refs.
//func (repo *GitRepo) mergeArchives(archive, remoteArchive string) error {
// remoteHash, err := repo.GetCommitHash(remoteArchive)
// if err != nil {
// return err
// }
// if remoteHash == "" {
// // The remote archive does not exist, so we have nothing to do
// return nil
// }
//
// archiveHash, err := repo.GetCommitHash(archive)
// if err != nil {
// return err
// }
// if archiveHash == "" {
// // The local archive does not exist, so we merely need to set it
// _, err := repo.runGitCommand("update-ref", archive, remoteHash)
// return err
// }
//
// isAncestor, err := repo.IsAncestor(archiveHash, remoteHash)
// if err != nil {
// return err
// }
// if isAncestor {
// // The archive can simply be fast-forwarded
// _, err := repo.runGitCommand("update-ref", archive, remoteHash, archiveHash)
// return err
// }
//
// // Create a merge commit of the two archives
// refDetails, err := repo.GetCommitDetails(remoteArchive)
// if err != nil {
// return err
// }
// newArchiveHash, err := repo.runGitCommand("commit-tree", "-p", remoteHash, "-p", archiveHash, "-m", "Merge local and remote archives", refDetails.Tree)
// if err != nil {
// return err
// }
// newArchiveHash = strings.TrimSpace(newArchiveHash)
// _, err = repo.runGitCommand("update-ref", archive, newArchiveHash, archiveHash)
// return err
//}
//
//// ArchiveRef adds the current commit pointed to by the 'ref' argument
//// under the ref specified in the 'archive' argument.
////
//// Both the 'ref' and 'archive' arguments are expected to be the fully
//// qualified names of git refs (e.g. 'refs/heads/my-change' or
//// 'refs/devtools/archives/reviews').
////
//// If the ref pointed to by the 'archive' argument does not exist
//// yet, then it will be created.
//func (repo *GitRepo) ArchiveRef(ref, archive string) error {
// refHash, err := repo.GetCommitHash(ref)
// if err != nil {
// return err
// }
// refDetails, err := repo.GetCommitDetails(ref)
// if err != nil {
// return err
// }
//
// commitTreeArgs := []string{"commit-tree"}
// archiveHash, err := repo.GetCommitHash(archive)
// if err != nil {
// archiveHash = ""
// } else {
// commitTreeArgs = append(commitTreeArgs, "-p", archiveHash)
// }
// commitTreeArgs = append(commitTreeArgs, "-p", refHash, "-m", fmt.Sprintf("Archive %s", refHash), refDetails.Tree)
// newArchiveHash, err := repo.runGitCommand(commitTreeArgs...)
// if err != nil {
// return err
// }
// newArchiveHash = strings.TrimSpace(newArchiveHash)
// updateRefArgs := []string{"update-ref", archive, newArchiveHash}
// if archiveHash != "" {
// updateRefArgs = append(updateRefArgs, archiveHash)
// }
// _, err = repo.runGitCommand(updateRefArgs...)
// return err
//}
//
//// MergeRef merges the given ref into the current one.
////
//// The ref argument is the ref to merge, and fastForward indicates that the
//// current ref should only move forward, as opposed to creating a bubble merge.
//// The messages argument(s) provide text that should be included in the default
//// merge commit message (separated by blank lines).
//func (repo *GitRepo) MergeRef(ref string, fastForward bool, messages ...string) error {
// args := []string{"merge"}
// if fastForward {
// args = append(args, "--ff", "--ff-only")
// } else {
// args = append(args, "--no-ff")
// }
// if len(messages) > 0 {
// commitMessage := strings.Join(messages, "\n\n")
// args = append(args, "-e", "-m", commitMessage)
// }
// args = append(args, ref)
// return repo.runGitCommandInline(args...)
//}
//
//// RebaseRef rebases the current ref onto the given one.
//func (repo *GitRepo) RebaseRef(ref string) error {
// return repo.runGitCommandInline("rebase", "-i", ref)
//}
//
//// ListCommits returns the list of commits reachable from the given ref.
////
//// The generated list is in chronological order (with the oldest commit first).
////
//// If the specified ref does not exist, then this method returns an empty result.
//func (repo *GitRepo) ListCommits(ref string) []string {
// var stdout bytes.Buffer
// var stderr bytes.Buffer
// if err := repo.runGitCommandWithIO(nil, &stdout, &stderr, "rev-list", "--reverse", ref); err != nil {
// return nil
// }
//
// byteLines := bytes.Split(stdout.Bytes(), []byte("\n"))
// var commits []string
// for _, byteLine := range byteLines {
// commits = append(commits, string(byteLine))
// }
// return commits
//}
//
//// ListCommitsBetween returns the list of commits between the two given revisions.
////
//// The "from" parameter is the starting point (exclusive), and the "to"
//// parameter is the ending point (inclusive).
////
//// The "from" commit does not need to be an ancestor of the "to" commit. If it
//// is not, then the merge base of the two is used as the starting point.
//// Admittedly, this makes calling these the "between" commits is a bit of a
//// misnomer, but it also makes the method easier to use when you want to
//// generate the list of changes in a feature branch, as it eliminates the need
//// to explicitly calculate the merge base. This also makes the semantics of the
//// method compatible with git's built-in "rev-list" command.
////
//// The generated list is in chronological order (with the oldest commit first).
//func (repo *GitRepo) ListCommitsBetween(from, to string) ([]string, error) {
// out, err := repo.runGitCommand("rev-list", "--reverse", from+".."+to)
// if err != nil {
// return nil, err
// }
// if out == "" {
// return nil, nil
// }
// return strings.Split(out, "\n"), nil
//}
//
//// GetNotes uses the "git" command-line tool to read the notes from the given ref for a given revision.
//func (repo *GitRepo) GetNotes(notesRef, revision string) []Note {
// var notes []Note
// rawNotes, err := repo.runGitCommand("notes", "--ref", notesRef, "show", revision)
// if err != nil {
// // We just assume that this means there are no notes
// return nil
// }
// for _, line := range strings.Split(rawNotes, "\n") {
// notes = append(notes, Note([]byte(line)))
// }
// return notes
//}
//
//func stringsReader(s []*string) io.Reader {
// var subReaders []io.Reader
// for _, strPtr := range s {
// subReader := strings.NewReader(*strPtr)
// subReaders = append(subReaders, subReader, strings.NewReader("\n"))
// }
// return io.MultiReader(subReaders...)
//}
//
//// splitBatchCheckOutput parses the output of a 'git cat-file --batch-check=...' command.
////
//// The output is expected to be formatted as a series of entries, with each
//// entry consisting of:
//// 1. The SHA1 hash of the git object being output, followed by a space.
//// 2. The git "type" of the object (commit, blob, tree, missing, etc), followed by a newline.
////
//// To generate this format, make sure that the 'git cat-file' command includes
//// the argument '--batch-check=%(objectname) %(objecttype)'.
////
//// The return value is a map from object hash to a boolean indicating if that object is a commit.
//func splitBatchCheckOutput(out *bytes.Buffer) (map[string]bool, error) {
// isCommit := make(map[string]bool)
// reader := bufio.NewReader(out)
// for {
// nameLine, err := reader.ReadString(byte(' '))
// if err == io.EOF {
// return isCommit, nil
// }
// if err != nil {
// return nil, fmt.Errorf("Failure while reading the next object name: %v", err)
// }
// nameLine = strings.TrimSuffix(nameLine, " ")
// typeLine, err := reader.ReadString(byte('\n'))
// if err != nil && err != io.EOF {
// return nil, fmt.Errorf("Failure while reading the next object type: %q - %v", nameLine, err)
// }
// typeLine = strings.TrimSuffix(typeLine, "\n")
// if typeLine == "commit" {
// isCommit[nameLine] = true
// }
// }
//}
//
//// splitBatchCatFileOutput parses the output of a 'git cat-file --batch=...' command.
////
//// The output is expected to be formatted as a series of entries, with each
//// entry consisting of:
//// 1. The SHA1 hash of the git object being output, followed by a newline.
//// 2. The size of the object's contents in bytes, followed by a newline.
//// 3. The objects contents.
////
//// To generate this format, make sure that the 'git cat-file' command includes
//// the argument '--batch=%(objectname)\n%(objectsize)'.
//func splitBatchCatFileOutput(out *bytes.Buffer) (map[string][]byte, error) {
// contentsMap := make(map[string][]byte)
// reader := bufio.NewReader(out)
// for {
// nameLine, err := reader.ReadString(byte('\n'))
// if strings.HasSuffix(nameLine, "\n") {
// nameLine = strings.TrimSuffix(nameLine, "\n")
// }
// if err == io.EOF {
// return contentsMap, nil
// }
// if err != nil {
// return nil, fmt.Errorf("Failure while reading the next object name: %v", err)
// }
// sizeLine, err := reader.ReadString(byte('\n'))
// if strings.HasSuffix(sizeLine, "\n") {
// sizeLine = strings.TrimSuffix(sizeLine, "\n")
// }
// if err != nil {
// return nil, fmt.Errorf("Failure while reading the next object size: %q - %v", nameLine, err)
// }
// size, err := strconv.Atoi(sizeLine)
// if err != nil {
// return nil, fmt.Errorf("Failure while parsing the next object size: %q - %v", nameLine, err)
// }
// contentBytes := make([]byte, size, size)
// readDest := contentBytes
// len := 0
// err = nil
// for err == nil && len < size {
// nextLen := 0
// nextLen, err = reader.Read(readDest)
// len += nextLen
// readDest = contentBytes[len:]
// }
// contentsMap[nameLine] = contentBytes
// if err == io.EOF {
// return contentsMap, nil
// }
// if err != nil {
// return nil, err
// }
// for bs, err := reader.Peek(1); err == nil && bs[0] == byte('\n'); bs, err = reader.Peek(1) {
// reader.ReadByte()
// }
// }
//}
//
//// notesMapping represents the association between a git object and the notes for that object.
//type notesMapping struct {
// ObjectHash *string
// NotesHash *string
//}
//
//// notesOverview represents a high-level overview of all the notes under a single notes ref.
//type notesOverview struct {
// NotesMappings []*notesMapping
// ObjectHashesReader io.Reader
// NotesHashesReader io.Reader
//}
//
//// notesOverview returns an overview of the git notes stored under the given ref.
//func (repo *GitRepo) notesOverview(notesRef string) (*notesOverview, error) {
// var stdout bytes.Buffer
// var stderr bytes.Buffer
// if err := repo.runGitCommandWithIO(nil, &stdout, &stderr, "notes", "--ref", notesRef, "list"); err != nil {
// return nil, err
// }
//
// var notesMappings []*notesMapping
// var objHashes []*string
// var notesHashes []*string
// outScanner := bufio.NewScanner(&stdout)
// for outScanner.Scan() {
// line := outScanner.Text()
// lineParts := strings.Split(line, " ")
// if len(lineParts) != 2 {
// return nil, fmt.Errorf("Malformed output line from 'git-notes list': %q", line)
// }
// objHash := &lineParts[1]
// notesHash := &lineParts[0]
// notesMappings = append(notesMappings, ¬esMapping{
// ObjectHash: objHash,
// NotesHash: notesHash,
// })
// objHashes = append(objHashes, objHash)
// notesHashes = append(notesHashes, notesHash)
// }
// err := outScanner.Err()
// if err != nil && err != io.EOF {
// return nil, fmt.Errorf("Failure parsing the output of 'git-notes list': %v", err)
// }
// return ¬esOverview{
// NotesMappings: notesMappings,
// ObjectHashesReader: stringsReader(objHashes),
// NotesHashesReader: stringsReader(notesHashes),
// }, nil
//}
//
//// getIsCommitMap returns a mapping of all the annotated objects that are commits.
//func (overview *notesOverview) getIsCommitMap(repo *GitRepo) (map[string]bool, error) {
// var stdout bytes.Buffer
// var stderr bytes.Buffer
// if err := repo.runGitCommandWithIO(overview.ObjectHashesReader, &stdout, &stderr, "cat-file", "--batch-check=%(objectname) %(objecttype)"); err != nil {
// return nil, fmt.Errorf("Failure performing a batch file check: %v", err)
// }
// isCommit, err := splitBatchCheckOutput(&stdout)
// if err != nil {
// return nil, fmt.Errorf("Failure parsing the output of a batch file check: %v", err)
// }
// return isCommit, nil
//}
//
//// getNoteContentsMap returns a mapping from all the notes hashes to their contents.
//func (overview *notesOverview) getNoteContentsMap(repo *GitRepo) (map[string][]byte, error) {
// var stdout bytes.Buffer
// var stderr bytes.Buffer
// if err := repo.runGitCommandWithIO(overview.NotesHashesReader, &stdout, &stderr, "cat-file", "--batch=%(objectname)\n%(objectsize)"); err != nil {
// return nil, fmt.Errorf("Failure performing a batch file read: %v", err)
// }
// noteContentsMap, err := splitBatchCatFileOutput(&stdout)
// if err != nil {
// return nil, fmt.Errorf("Failure parsing the output of a batch file read: %v", err)
// }
// return noteContentsMap, nil
//}
//
//// GetAllNotes reads the contents of the notes under the given ref for every commit.
////
//// The returned value is a mapping from commit hash to the list of notes for that commit.
////
//// This is the batch version of the corresponding GetNotes(...) method.
//func (repo *GitRepo) GetAllNotes(notesRef string) (map[string][]Note, error) {
// // This code is unfortunately quite complicated, but it needs to be so.
// //
// // Conceptually, this is equivalent to:
// // result := make(map[string][]Note)
// // for _, commit := range repo.ListNotedRevisions(notesRef) {
// // result[commit] = repo.GetNotes(notesRef, commit)
// // }
// // return result, nil
// //
// // However, that logic would require separate executions of the 'git'
// // command for every annotated commit. For a repo with 10s of thousands
// // of reviews, that would mean calling Cmd.Run(...) 10s of thousands of
// // times. That, in turn, would take so long that the tool would be unusable.
// //
// // This method avoids that by taking advantage of the 'git cat-file --batch="..."'
// // command. That allows us to use a single invocation of Cmd.Run(...) to
// // inspect multiple git objects at once.
// //
// // As such, regardless of the number of reviews in a repo, we can get all
// // of the notes using a total of three invocations of Cmd.Run(...):
// // 1. One to list all the annotated objects (and their notes hash)
// // 2. A second one to filter out all of the annotated objects that are not commits.
// // 3. A final one to get the contents of all of the notes blobs.
// overview, err := repo.notesOverview(notesRef)
// if err != nil {
// return nil, err
// }
// isCommit, err := overview.getIsCommitMap(repo)
// if err != nil {
// return nil, fmt.Errorf("Failure building the set of commit objects: %v", err)
// }
// noteContentsMap, err := overview.getNoteContentsMap(repo)
// if err != nil {
// return nil, fmt.Errorf("Failure building the mapping from notes hash to contents: %v", err)
// }
// commitNotesMap := make(map[string][]Note)
// for _, notesMapping := range overview.NotesMappings {
// if !isCommit[*notesMapping.ObjectHash] {
// continue
// }
// noteBytes := noteContentsMap[*notesMapping.NotesHash]
// byteSlices := bytes.Split(noteBytes, []byte("\n"))
// var notes []Note
// for _, slice := range byteSlices {
// notes = append(notes, Note(slice))
// }
// commitNotesMap[*notesMapping.ObjectHash] = notes
// }
//
// return commitNotesMap, nil
//}
//
//// AppendNote appends a note to a revision under the given ref.
//func (repo *GitRepo) AppendNote(notesRef, revision string, note Note) error {
// _, err := repo.runGitCommand("notes", "--ref", notesRef, "append", "-m", string(note), revision)
// return err
//}
//
//// ListNotedRevisions returns the collection of revisions that are annotated by notes in the given ref.
//func (repo *GitRepo) ListNotedRevisions(notesRef string) []string {
// var revisions []string
// notesListOut, err := repo.runGitCommand("notes", "--ref", notesRef, "list")
// if err != nil {
// return nil
// }
// notesList := strings.Split(notesListOut, "\n")
// for _, notePair := range notesList {
// noteParts := strings.SplitN(notePair, " ", 2)
// if len(noteParts) == 2 {
// objHash := noteParts[1]
// objType, err := repo.runGitCommand("cat-file", "-t", objHash)
// // If a note points to an object that we do not know about (yet), then err will not
// // be nil. We can safely just ignore those notes.
// if err == nil && objType == "commit" {
// revisions = append(revisions, objHash)
// }
// }
// }
// return revisions
//}
//
//// PushNotes pushes git notes to a remote repo.
//func (repo *GitRepo) PushNotes(remote, notesRefPattern string) error {
// refspec := fmt.Sprintf("%s:%s", notesRefPattern, notesRefPattern)
//
// // The push is liable to fail if the user forgot to do a pull first, so
// // we treat errors as user errors rather than fatal errors.
// err := repo.runGitCommandInline("push", remote, refspec)
// if err != nil {
// return fmt.Errorf("Failed to push to the remote '%s': %v", remote, err)
// }
// return nil
//}
//
//// PushNotesAndArchive pushes the given notes and archive refs to a remote repo.
//func (repo *GitRepo) PushNotesAndArchive(remote, notesRefPattern, archiveRefPattern string) error {
// notesRefspec := fmt.Sprintf("%s:%s", notesRefPattern, notesRefPattern)
// archiveRefspec := fmt.Sprintf("%s:%s", archiveRefPattern, archiveRefPattern)
// err := repo.runGitCommandInline("push", remote, notesRefspec, archiveRefspec)
// if err != nil {
// return fmt.Errorf("Failed to push the local archive to the remote '%s': %v", remote, err)
// }
// return nil
//}
//
//func getRemoteNotesRef(remote, localNotesRef string) string {
// relativeNotesRef := strings.TrimPrefix(localNotesRef, "refs/notes/")
// return "refs/notes/" + remote + "/" + relativeNotesRef
//}
//
//func (repo *GitRepo) mergeRemoteNotes(remote, notesRefPattern string) error {
// remoteRefs, err := repo.runGitCommand("ls-remote", remote, notesRefPattern)
// if err != nil {
// return err
// }
// for _, line := range strings.Split(remoteRefs, "\n") {
// lineParts := strings.Split(line, "\t")
// if len(lineParts) == 2 {
// ref := lineParts[1]
// remoteRef := getRemoteNotesRef(remote, ref)
// _, err := repo.runGitCommand("notes", "--ref", ref, "merge", remoteRef, "-s", "cat_sort_uniq")
// if err != nil {
// return err
// }
// }
// }
// return nil
//}
//
//// PullNotes fetches the contents of the given notes ref from a remote repo,
//// and then merges them with the corresponding local notes using the
//// "cat_sort_uniq" strategy.
//func (repo *GitRepo) PullNotes(remote, notesRefPattern string) error {
// remoteNotesRefPattern := getRemoteNotesRef(remote, notesRefPattern)
// fetchRefSpec := fmt.Sprintf("+%s:%s", notesRefPattern, remoteNotesRefPattern)
// err := repo.runGitCommandInline("fetch", remote, fetchRefSpec)
// if err != nil {
// return err
// }
//
// return repo.mergeRemoteNotes(remote, notesRefPattern)
//}
//
//func getRemoteArchiveRef(remote, archiveRefPattern string) string {
// relativeArchiveRef := strings.TrimPrefix(archiveRefPattern, "refs/devtools/archives/")
// return "refs/devtools/remoteArchives/" + remote + "/" + relativeArchiveRef
//}
//
//func (repo *GitRepo) mergeRemoteArchives(remote, archiveRefPattern string) error {
// remoteRefs, err := repo.runGitCommand("ls-remote", remote, archiveRefPattern)
// if err != nil {
// return err
// }
// for _, line := range strings.Split(remoteRefs, "\n") {
// lineParts := strings.Split(line, "\t")
// if len(lineParts) == 2 {
// ref := lineParts[1]
// remoteRef := getRemoteArchiveRef(remote, ref)
// if err := repo.mergeArchives(ref, remoteRef); err != nil {
// return err
// }
// }
// }
// return nil
//}
//
//// PullNotesAndArchive fetches the contents of the notes and archives refs from
//// a remote repo, and merges them with the corresponding local refs.
////
//// For notes refs, we assume that every note can be automatically merged using
//// the 'cat_sort_uniq' strategy (the git-appraise schemas fit that requirement),
//// so we automatically merge the remote notes into the local notes.
////
//// For "archive" refs, they are expected to be used solely for maintaining
//// reachability of commits that are part of the history of any reviews,
//// so we do not maintain any consistency with their tree objects. Instead,
//// we merely ensure that their history graph includes every commit that we
//// intend to keep.
//func (repo *GitRepo) PullNotesAndArchive(remote, notesRefPattern, archiveRefPattern string) error {
// remoteArchiveRef := getRemoteArchiveRef(remote, archiveRefPattern)
// archiveFetchRefSpec := fmt.Sprintf("+%s:%s", archiveRefPattern, remoteArchiveRef)
//
// remoteNotesRefPattern := getRemoteNotesRef(remote, notesRefPattern)
// notesFetchRefSpec := fmt.Sprintf("+%s:%s", notesRefPattern, remoteNotesRefPattern)
//
// err := repo.runGitCommandInline("fetch", remote, notesFetchRefSpec, archiveFetchRefSpec)
// if err != nil {
// return err
// }
//
// if err := repo.mergeRemoteNotes(remote, notesRefPattern); err != nil {
// return err
// }
// if err := repo.mergeRemoteArchives(remote, archiveRefPattern); err != nil {
// return err
// }
// return nil
//}
*/
