diff options
Diffstat (limited to 'third_party/go/git-appraise/repository/git.go')
| -rw-r--r-- | third_party/go/git-appraise/repository/git.go | 987 |
1 files changed, 987 insertions, 0 deletions
diff --git a/third_party/go/git-appraise/repository/git.go b/third_party/go/git-appraise/repository/git.go new file mode 100644 index 0000000000..31d27ea6d2 --- /dev/null +++ b/third_party/go/git-appraise/repository/git.go @@ -0,0 +1,987 @@ +/* +Copyright 2015 Google Inc. All rights reserved. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +// Package repository contains helper methods for working with the Git repo. +package repository + +import ( + "bufio" + "bytes" + "crypto/sha1" + "encoding/json" + "fmt" + "io" + "os" + "os/exec" + "strconv" + "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, error := repo.runGitCommand("show-ref") + return fmt.Sprintf("%x", sha1.Sum([]byte(stateSummary))), error +} + +// 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") +} + +// GetUserSigningKey returns the key id the user has configured for +// sigining git artifacts. +func (repo *GitRepo) GetUserSigningKey() (string, error) { + return repo.runGitCommand("config", "user.signingKey") +} + +// 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") +} + +// 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...) +} + +// MergeAndSignRef merges the given ref into the current one and signs the +// merge. +// +// 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) MergeAndSignRef(ref string, fastForward bool, + messages ...string) error { + + args := []string{"merge"} + if fastForward { + args = append(args, "--ff", "--ff-only", "-S") + } else { + args = append(args, "--no-ff", "-S") + } + 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) +} + +// RebaseAndSignRef rebases the current ref onto the given one and signs the +// result. +func (repo *GitRepo) RebaseAndSignRef(ref string) error { + return repo.runGitCommandInline("rebase", "-S", "-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 +} + +// MergeNotes merges in the remote's state of the notes reference into the +// local repository's. +func (repo *GitRepo) MergeNotes(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.MergeNotes(remote, notesRefPattern) +} + +func getRemoteArchiveRef(remote, archiveRefPattern string) string { + relativeArchiveRef := strings.TrimPrefix(archiveRefPattern, "refs/devtools/archives/") + return "refs/devtools/remoteArchives/" + remote + "/" + relativeArchiveRef +} + +// MergeArchives merges in the remote's state of the archives reference into +// the local repository's. +func (repo *GitRepo) MergeArchives(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 +} + +func (repo *GitRepo) fetchNotes(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) + + return repo.runGitCommandInline("fetch", remote, notesFetchRefSpec, archiveFetchRefSpec) +} + +// 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 { + err := repo.fetchNotes(remote, notesRefPattern, archiveRefPattern) + if err != nil { + return err + } + + err = repo.MergeNotes(remote, notesRefPattern) + if err != nil { + return err + } + return repo.MergeArchives(remote, archiveRefPattern) +} + +// FetchAndReturnNewReviewHashes fetches the notes "branches" and then susses +// out the IDs (the revision the review points to) of any new reviews, then +// returns that list of IDs. +// +// This is accomplished by determining which files in the notes tree have +// changed because the _names_ of these files correspond to the revisions they +// point to. +func (repo *GitRepo) FetchAndReturnNewReviewHashes(remote, notesRefPattern, + archiveRefPattern string) ([]string, error) { + + // Record the current state of the reviews and comments refs. + var ( + getAllRevs, getAllComs bool + reviewsList, commentsList []string + ) + reviewBeforeHash, err := repo.GetCommitHash( + "notes/" + remote + "/devtools/reviews") + getAllRevs = err != nil + + commentBeforeHash, err := repo.GetCommitHash( + "notes/" + remote + "/devtools/discuss") + getAllComs = err != nil + + // Update them from the remote. + err = repo.fetchNotes(remote, notesRefPattern, archiveRefPattern) + if err != nil { + return nil, err + } + + // Now, if either of these are new refs, we just use the whole tree at that + // new ref. Otherwise we see which reviews or comments changed and collect + // them into a list. + if getAllRevs { + hash, err := repo.GetCommitHash( + "notes/" + remote + "/devtools/reviews") + // It is possible that even after we've pulled that this ref still + // isn't present (because there are no reviews yet). + if err == nil { + rvws, err := repo.runGitCommand("ls-tree", "-r", "--name-only", + hash) + if err != nil { + return nil, err + } + reviewsList = strings.Split(strings.Replace(rvws, "/", "", -1), + "\n") + } + } else { + reviewAfterHash, err := repo.GetCommitHash( + "notes/" + remote + "/devtools/reviews") + if err != nil { + return nil, err + } + + // Only run through this if the fetch fetched new revisions. + // Otherwise leave reviewsList as its default value, an empty slice + // of strings. + if reviewBeforeHash != reviewAfterHash { + newReviewsRaw, err := repo.runGitCommand("diff", "--name-only", + reviewBeforeHash, reviewAfterHash) + if err != nil { + return nil, err + } + reviewsList = strings.Split(strings.Replace(newReviewsRaw, + "/", "", -1), "\n") + } + } + + if getAllComs { + hash, err := repo.GetCommitHash( + "notes/" + remote + "/devtools/discuss") + // It is possible that even after we've pulled that this ref still + // isn't present (because there are no comments yet). + if err == nil { + rvws, err := repo.runGitCommand("ls-tree", "-r", "--name-only", + hash) + if err != nil { + return nil, err + } + commentsList = strings.Split(strings.Replace(rvws, "/", "", -1), + "\n") + } + } else { + commentAfterHash, err := repo.GetCommitHash( + "notes/" + remote + "/devtools/discuss") + if err != nil { + return nil, err + } + + // Only run through this if the fetch fetched new revisions. + // Otherwise leave commentsList as its default value, an empty slice + // of strings. + if commentBeforeHash != commentAfterHash { + newCommentsRaw, err := repo.runGitCommand("diff", "--name-only", + commentBeforeHash, commentAfterHash) + if err != nil { + return nil, err + } + commentsList = strings.Split(strings.Replace(newCommentsRaw, + "/", "", -1), "\n") + } + } + + // Now that we have our two lists, we need to merge them. + updatedReviewSet := make(map[string]struct{}) + for _, hash := range append(reviewsList, commentsList...) { + updatedReviewSet[hash] = struct{}{} + } + + updatedReviews := make([]string, 0, len(updatedReviewSet)) + for key, _ := range updatedReviewSet { + updatedReviews = append(updatedReviews, key) + } + return updatedReviews, nil +} |