func TreeWalk(r *git.Repository, t *git.Tree, key string, h func(string, git.Object) error) error {
if t == nil {
return fmt.Errorf("no tree to walk")
}
subtree, err := TreeScope(r, t, key)
if err != nil {
return err
}
var handlerErr error
err = subtree.Walk(func(parent string, e *git.TreeEntry) int {
obj, err := r.Lookup(e.Id)
if err != nil {
handlerErr = err
return -1
}
if err := h(path.Join(parent, e.Name), obj); err != nil {
handlerErr = err
return -1
}
obj.Free()
return 0
})
if handlerErr != nil {
return handlerErr
}
if err != nil {
return err
}
return nil
}
// emptyTree creates an empty Git tree and returns its ID
// (the ID will always be the same)
func emptyTree(repo *git.Repository) (*git.Oid, error) {
builder, err := repo.TreeBuilder()
if err != nil {
return nil, err
}
return builder.Write()
}
// Removes a key from the tree.
func treeDel(repo *git.Repository, tree *git.Tree, key string) (*git.Tree, error) {
var err error
key = TreePath(key)
base, leaf := path.Split(key)
if tree != nil {
if tree, err = TreeScope(repo, tree, base); err != nil {
return nil, err
}
}
builder, err := repo.TreeBuilderFromTree(tree)
if err != nil {
return nil, err
}
if err := builder.Remove(leaf); err != nil {
return nil, err
}
treeId, err := builder.Write()
if err != nil {
return nil, err
}
newTree, err := lookupTree(repo, treeId)
if err != nil {
return nil, err
}
return newTree, err
}
// lookupBlob looks up an object at hash `id` in `repo`, and returns
// it as a git blob. If the object is not a blob, an error is returned.
func lookupBlob(r *git.Repository, id *git.Oid) (*git.Blob, error) {
obj, err := r.Lookup(id)
if err != nil {
return nil, err
}
if blob, ok := obj.(*git.Blob); ok {
return blob, nil
}
return nil, fmt.Errorf("hash %v exist but is not a blob", id)
}
// lookupCommit looks up an object at hash `id` in `repo`, and returns
// it as a git commit. If the object is not a commit, an error is returned.
func lookupCommit(r *git.Repository, id *git.Oid) (*git.Commit, error) {
obj, err := r.Lookup(id)
if err != nil {
return nil, err
}
if commit, ok := obj.(*git.Commit); ok {
return commit, nil
}
return nil, fmt.Errorf("hash %v exist but is not a commit", id)
}
func lookupTree(r *git.Repository, id *git.Oid) (*git.Tree, error) {
obj, err := r.Lookup(id)
if err != nil {
return nil, err
}
if tree, ok := obj.(*git.Tree); ok {
return tree, nil
}
return nil, fmt.Errorf("hash %v exist but is not a tree", id)
}
// lookupTip looks up the object referenced by refname, and returns it
// as a Commit object. If the reference does not exist, or if object is
// not a commit, nil is returned. Other errors cannot be detected.
func lookupTip(r *git.Repository, refname string) *git.Commit {
ref, err := r.LookupReference(refname)
if err != nil {
return nil
}
commit, err := lookupCommit(r, ref.Target())
if err != nil {
return nil
}
return commit
}
// TemoraryCsvPath returns the repository's path to the temp folder.
func TemporaryCsvPath(r *git.Repository) (string, error) {
// Create unique csv file name through path.
fileName := strings.Replace(r.Path(), "/", "_", -1)
var buffer bytes.Buffer
// Current path
currentPath, err := os.Getwd()
if err != nil {
return "", err
}
buffer.WriteString(currentPath)
buffer.WriteString("/tmp/")
buffer.WriteString(fileName)
buffer.WriteString(".csv")
return buffer.String(), nil
}
// NewTreeFS creates a git Tree FS. The treeish should resolve to tree SHA1.
func NewTreeFSRoot(repo *git.Repository, treeish string, opts *GitFSOptions) (nodefs.Node, error) {
obj, err := repo.RevparseSingle(treeish)
if err != nil {
return nil, err
}
defer obj.Free()
var treeId *git.Oid
switch obj.Type() {
case git.ObjectCommit:
commit, err := repo.LookupCommit(obj.Id())
if err != nil {
return nil, err
}
treeId = commit.TreeId()
case git.ObjectTree:
treeId = obj.Id()
default:
return nil, fmt.Errorf("gitfs: unsupported object type %d", obj.Type())
}
if opts == nil {
opts = &GitFSOptions{
Lazy: true,
Disk: false,
}
}
if opts.TempDir == "" {
opts.TempDir, err = ioutil.TempDir("", "gitfs")
if err != nil {
return nil, err
}
}
t := &treeFS{
repo: repo,
opts: *opts,
}
root := t.newDirNode(treeId)
return root, nil
}
func mkCommit(r *git.Repository, refname string, msg string, tree *git.Tree, parent *git.Commit, extraParents ...*git.Commit) (*git.Commit, error) {
var parents []*git.Commit
if parent != nil {
parents = append(parents, parent)
}
if len(extraParents) > 0 {
parents = append(parents, extraParents...)
}
id, err := r.CreateCommit(
refname,
&git.Signature{"libpack", "libpack", time.Now()}, // author
&git.Signature{"libpack", "libpack", time.Now()}, // committer
msg,
tree, // git tree to commit
parents...,
)
if err != nil {
return nil, err
}
return lookupCommit(r, id)
}
// treeAdd creates a new Git tree by adding a new object
// to it at the specified path.
// Intermediary subtrees are created as needed.
// If an object already exists at key or any intermediary path,
// it is overwritten.
//
// - If merge is true, new trees are merged into existing ones at the
// file granularity (similar to 'cp -R').
// - If it is false, existing trees are completely shadowed (similar to 'mount')
//
// Since git trees are immutable, base is not modified. The new
// tree is returned.
// If an error is encountered, intermediary objects may be left
// behind in the git repository. It is the caller's responsibility
// to perform garbage collection, if any.
// FIXME: manage garbage collection, or provide a list of created
// objects.
func treeAdd(repo *git.Repository, tree *git.Tree, key string, valueId *git.Oid, merge bool) (t *git.Tree, err error) {
/*
** // Primitive but convenient tracing for debugging recursive calls to treeAdd.
** // Uncomment this block for debug output.
**
** var callString string
** if tree != nil {
** callString = fmt.Sprintf(" treeAdd %v:\t\t%s\t\t\t= %v", tree.Id(), key, valueId)
** } else {
** callString = fmt.Sprintf(" treeAdd %v:\t\t%s\t\t\t= %v", tree, key, valueId)
** }
** fmt.Printf(" %s\n", callString)
** defer func() {
** if t != nil {
** fmt.Printf("-> %s => %v\n", callString, t.Id())
** } else {
** fmt.Printf("-> %s => %v\n", callString, err)
** }
** }()
*/
if valueId == nil {
return tree, nil
}
key = TreePath(key)
base, leaf := path.Split(key)
o, err := repo.Lookup(valueId)
if err != nil {
return nil, err
}
var builder *git.TreeBuilder
if tree == nil {
builder, err = repo.TreeBuilder()
if err != nil {
return nil, err
}
} else {
builder, err = repo.TreeBuilderFromTree(tree)
if err != nil {
return nil, err
}
}
defer builder.Free()
// The specified path has only 1 component (the "leaf")
if base == "" || base == "/" {
// If val is a string, set it and we're done.
// Any old value is overwritten.
if _, isBlob := o.(*git.Blob); isBlob {
if err := builder.Insert(leaf, valueId, 0100644); err != nil {
return nil, err
}
newTreeId, err := builder.Write()
if err != nil {
return nil, err
}
newTree, err := lookupTree(repo, newTreeId)
if err != nil {
return nil, err
}
return newTree, nil
}
// If val is not a string, it must be a subtree.
// Return an error if it's any other type than Tree.
oTree, ok := o.(*git.Tree)
if !ok {
return nil, fmt.Errorf("value must be a blob or subtree")
}
var subTree *git.Tree
var oldSubTree *git.Tree
if tree != nil {
oldSubTree, err = TreeScope(repo, tree, leaf)
// FIXME: distinguish "no such key" error (which
// FIXME: distinguish a non-existing previous tree (continue with oldTree==nil)
// from other errors (abort and return an error)
if err == nil {
defer oldSubTree.Free()
}
}
// If that subtree already exists, merge the new one in.
if merge && oldSubTree != nil {
subTree = oldSubTree
for i := uint64(0); i < oTree.EntryCount(); i++ {
var err error
e := oTree.EntryByIndex(i)
subTree, err = treeAdd(repo, subTree, e.Name, e.Id, merge)
if err != nil {
return nil, err
}
}
} else {
subTree = oTree
}
// If the key is /, we're replacing the current tree
if key == "/" {
return subTree, nil
}
// Otherwise we're inserting into the current tree
if err := builder.Insert(leaf, subTree.Id(), 040000); err != nil {
return nil, err
}
newTreeId, err := builder.Write()
if err != nil {
return nil, err
}
newTree, err := lookupTree(repo, newTreeId)
if err != nil {
return nil, err
}
return newTree, nil
}
subtree, err := treeAdd(repo, nil, leaf, valueId, merge)
if err != nil {
return nil, err
}
return treeAdd(repo, tree, base, subtree.Id(), merge)
}
func nukeRepo(repo *git.Repository) {
repo.Free()
os.RemoveAll(repo.Path())
}
func CommitToRef(r *git.Repository, tree *git.Tree, parent *git.Commit, refname, msg string) (*git.Commit, error) {
// Retry loop in case of conflict
// FIXME: use a custom inter-process lock as a first attempt for performance
var (
needMerge bool
tmpCommit *git.Commit
)
for {
if !needMerge {
// Create simple commit
commit, err := mkCommit(r, refname, msg, tree, parent)
if isGitConcurrencyErr(err) {
needMerge = true
continue
}
return commit, err
} else {
if tmpCommit == nil {
var err error
// Create a temporary intermediary commit, to pass to MergeCommits
// NOTE: this commit will not be part of the final history.
tmpCommit, err = mkCommit(r, "", msg, tree, parent)
if err != nil {
return nil, err
}
defer tmpCommit.Free()
}
// Lookup tip from ref
tip := lookupTip(r, refname)
if tip == nil {
// Ref may have been deleted after previous merge error
needMerge = false
continue
}
// Merge simple commit with the tip
opts, err := git.DefaultMergeOptions()
if err != nil {
return nil, err
}
idx, err := r.MergeCommits(tmpCommit, tip, &opts)
if err != nil {
return nil, err
}
conflicts, err := idx.ConflictIterator()
if err != nil {
return nil, err
}
defer conflicts.Free()
for {
c, err := conflicts.Next()
if isGitIterOver(err) {
break
} else if err != nil {
return nil, err
}
if c.Our != nil {
idx.RemoveConflict(c.Our.Path)
if err := idx.Add(c.Our); err != nil {
return nil, fmt.Errorf("error resolving merge conflict for '%s': %v", c.Our.Path, err)
}
}
}
mergedId, err := idx.WriteTreeTo(r)
if err != nil {
return nil, fmt.Errorf("WriteTree: %v", err)
}
mergedTree, err := lookupTree(r, mergedId)
if err != nil {
return nil, err
}
// Create new commit from merged tree (discarding simple commit)
commit, err := mkCommit(r, refname, msg, mergedTree, parent, tip)
if isGitConcurrencyErr(err) {
// FIXME: enforce a maximum number of retries to avoid infinite loops
continue
}
return commit, err
}
}
return nil, fmt.Errorf("too many failed merge attempts, giving up")
}