package object
import (
"container/list"
"io"
"github.com/go-git/go-git/v5/plumbing"
"github.com/go-git/go-git/v5/plumbing/storer"
"github.com/go-git/go-git/v5/storage"
)
type commitPreIterator struct {
seenExternal map[plumbing.Hash]bool
seen map[plumbing.Hash]bool
stack []CommitIter
start *Commit
}
// NewCommitPreorderIter returns a CommitIter that walks the commit history,
// starting at the given commit and visiting its parents in pre-order.
// The given callback will be called for each visited commit. Each commit will
// be visited only once. If the callback returns an error, walking will stop
// and will return the error. Other errors might be returned if the history
// cannot be traversed (e.g. missing objects). Ignore allows to skip some
// commits from being iterated.
func NewCommitPreorderIter(
c *Commit,
seenExternal map[plumbing.Hash]bool,
ignore []plumbing.Hash,
) CommitIter {
seen := make(map[plumbing.Hash]bool)
for _, h := range ignore {
seen[h] = true
}
return &commitPreIterator{
seenExternal: seenExternal,
seen: seen,
stack: make([]CommitIter, 0),
start: c,
}
}
func (w *commitPreIterator) Next() (*Commit, error) {
var c *Commit
for {
if w.start != nil {
c = w.start
w.start = nil
} else {
current := len(w.stack) - 1
if current < 0 {
return nil, io.EOF
}
var err error
c, err = w.stack[current].Next()
if err == io.EOF {
w.stack = w.stack[:current]
continue
}
if err != nil {
return nil, err
}
}
if w.seen[c.Hash] || w.seenExternal[c.Hash] {
continue
}
w.seen[c.Hash] = true
if c.NumParents() > 0 {
w.stack = append(w.stack, filteredParentIter(c, w.seen))
}
return c, nil
}
}
func filteredParentIter(c *Commit, seen map[plumbing.Hash]bool) CommitIter {
var hashes []plumbing.Hash
for _, h := range c.ParentHashes {
if !seen[h] {
hashes = append(hashes, h)
}
}
return NewCommitIter(c.s,
storer.NewEncodedObjectLookupIter(c.s, plumbing.CommitObject, hashes),
)
}
func (w *commitPreIterator) ForEach(cb func(*Commit) error) error {
for {
c, err := w.Next()
if err == io.EOF {
break
}
if err != nil {
return err
}
err = cb(c)
if err == storer.ErrStop {
break
}
if err != nil {
return err
}
}
return nil
}
func (w *commitPreIterator) Close() {}
type commitPostIterator struct {
stack []*Commit
seen map[plumbing.Hash]bool
}
// NewCommitPostorderIter returns a CommitIter that walks the commit
// history like WalkCommitHistory but in post-order. This means that after
// walking a merge commit, the merged commit will be walked before the base
// it was merged on. This can be useful if you wish to see the history in
// chronological order. Ignore allows to skip some commits from being iterated.
func NewCommitPostorderIter(c *Commit, ignore []plumbing.Hash) CommitIter {
seen := make(map[plumbing.Hash]bool)
for _, h := range ignore {
seen[h] = true
}
return &commitPostIterator{
stack: []*Commit{c},
seen: seen,
}
}
func (w *commitPostIterator) Next() (*Commit, error) {
for {
if len(w.stack) == 0 {
return nil, io.EOF
}
c := w.stack[len(w.stack)-1]
w.stack = w.stack[:len(w.stack)-1]
if w.seen[c.Hash] {
continue
}
w.seen[c.Hash] = true
return c, c.Parents().ForEach(func(p *Commit) error {
w.stack = append(w.stack, p)
return nil
})
}
}
func (w *commitPostIterator) ForEach(cb func(*Commit) error) error {
for {
c, err := w.Next()
if err == io.EOF {
break
}
if err != nil {
return err
}
err = cb(c)
if err == storer.ErrStop {
break
}
if err != nil {
return err
}
}
return nil
}
func (w *commitPostIterator) Close() {}
// commitAllIterator stands for commit iterator for all refs.
type commitAllIterator struct {
// currCommit points to the current commit.
currCommit *list.Element
}
// NewCommitAllIter returns a new commit iterator for all refs.
// repoStorer is a repo Storer used to get commits and references.
// commitIterFunc is a commit iterator function, used to iterate through ref commits in chosen order
func NewCommitAllIter(repoStorer storage.Storer, commitIterFunc func(*Commit) CommitIter) (CommitIter, error) {
commitsPath := list.New()
commitsLookup := make(map[plumbing.Hash]*list.Element)
head, err := storer.ResolveReference(repoStorer, plumbing.HEAD)
if err == nil {
err = addReference(repoStorer, commitIterFunc, head, commitsPath, commitsLookup)
}
if err != nil && err != plumbing.ErrReferenceNotFound {
return nil, err
}
// add all references along with the HEAD
refIter, err := repoStorer.IterReferences()
if err != nil {
return nil, err
}
defer refIter.Close()
for {
ref, err := refIter.Next()
if err == io.EOF {
break
}
if err == plumbing.ErrReferenceNotFound {
continue
}
if err != nil {
return nil, err
}
if err = addReference(repoStorer, commitIterFunc, ref, commitsPath, commitsLookup); err != nil {
return nil, err
}
}
return &commitAllIterator{commitsPath.Front()}, nil
}
func addReference(
repoStorer storage.Storer,
commitIterFunc func(*Commit) CommitIter,
ref *plumbing.Reference,
commitsPath *list.List,
commitsLookup map[plumbing.Hash]*list.Element) error {
_, exists := commitsLookup[ref.Hash()]
if exists {
// we already have it - skip the reference.
return nil
}
refCommit, _ := GetCommit(repoStorer, ref.Hash())
if refCommit == nil {
// if it's not a commit - skip it.
return nil
}
var (
refCommits []*Commit
parent *list.Element
)
// collect all ref commits to add
commitIter := commitIterFunc(refCommit)
for c, e := commitIter.Next(); e == nil; {
parent, exists = commitsLookup[c.Hash]
if exists {
break
}
refCommits = append(refCommits, c)
c, e = commitIter.Next()
}
commitIter.Close()
if parent == nil {
// common parent - not found
// add all commits to the path from this ref (maybe it's a HEAD and we don't have anything, yet)
for _, c := range refCommits {
parent = commitsPath.PushBack(c)
commitsLookup[c.Hash] = parent
}
} else {
// add ref's commits to the path in reverse order (from the latest)
for i := len(refCommits) - 1; i >= 0; i-- {
c := refCommits[i]
// insert before found common parent
parent = commitsPath.InsertBefore(c, parent)
commitsLookup[c.Hash] = parent
}
}
return nil
}
func (it *commitAllIterator) Next() (*Commit, error) {
if it.currCommit == nil {
return nil, io.EOF
}
c := it.currCommit.Value.(*Commit)
it.currCommit = it.currCommit.Next()
return c, nil
}
func (it *commitAllIterator) ForEach(cb func(*Commit) error) error {
for {
c, err := it.Next()
if err == io.EOF {
break
}
if err != nil {
return err
}
err = cb(c)
if err == storer.ErrStop {
break
}
if err != nil {
return err
}
}
return nil
}
func (it *commitAllIterator) Close() {
it.currCommit = nil
}
