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author | Santiago M. Mola <santi@mola.io> | 2016-12-14 23:12:44 +0100 |
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committer | Máximo Cuadros <mcuadros@gmail.com> | 2016-12-14 23:12:44 +0100 |
commit | 0af572dd21c0aa79d13745b633ee24ba6c4d6cf1 (patch) | |
tree | 49e81e74e82d84fd88b2fc1e4b0dc7c7bfe9c40f /plumbing/object/tag.go | |
parent | df0f38af83f972f026d7e14150f3d37b95f13484 (diff) | |
download | go-git-0af572dd21c0aa79d13745b633ee24ba6c4d6cf1.tar.gz |
move plumbing from top level package to plumbing (#183)
* plumbing: rename Object -> EncodedObject.
* plumbing/storer: rename ObjectStorer -> EncodedObjectStorer.
* move difftree to plumbing/difftree.
* move diff -> utils/diff
* make Object/Tag/Blob/Tree/Commit/File depend on storer.
* Object and its implementations now depend only on
storer.EncodedObjectStorer, not git.Repository.
* Tests are decoupled accordingly.
* move Object/Commit/File/Tag/Tree to plumbing/object.
* move Object/Commit/File/Tag/Tree to plumbing/object.
* move checkClose to utils/ioutil.
* move RevListObjects to plumbing/revlist.Objects.
* move DiffTree to plumbing/difftree package.
* rename files with plural nouns to singular
* plumbing/object: add GetBlob/GetCommit/GetTag/GetTree.
Diffstat (limited to 'plumbing/object/tag.go')
-rw-r--r-- | plumbing/object/tag.go | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/plumbing/object/tag.go b/plumbing/object/tag.go new file mode 100644 index 0000000..5ca363d --- /dev/null +++ b/plumbing/object/tag.go @@ -0,0 +1,268 @@ +package object + +import ( + "bufio" + "bytes" + "fmt" + "io" + stdioutil "io/ioutil" + + "gopkg.in/src-d/go-git.v4/plumbing" + "gopkg.in/src-d/go-git.v4/plumbing/storer" + "gopkg.in/src-d/go-git.v4/utils/ioutil" +) + +// Tag represents an annotated tag object. It points to a single git object of +// any type, but tags typically are applied to commit or blob objects. It +// provides a reference that associates the target with a tag name. It also +// contains meta-information about the tag, including the tagger, tag date and +// message. +// +// https://git-scm.com/book/en/v2/Git-Internals-Git-References#Tags +type Tag struct { + Hash plumbing.Hash + Name string + Tagger Signature + Message string + TargetType plumbing.ObjectType + Target plumbing.Hash + + s storer.EncodedObjectStorer +} + +// GetTag gets a tag from an object storer and decodes it. +func GetTag(s storer.EncodedObjectStorer, h plumbing.Hash) (*Tag, error) { + o, err := s.EncodedObject(plumbing.TagObject, h) + if err != nil { + return nil, err + } + + return DecodeTag(s, o) +} + +// DecodeTag decodes an encoded object into a *Commit and associates it to the +// given object storer. +func DecodeTag(s storer.EncodedObjectStorer, o plumbing.EncodedObject) (*Tag, error) { + t := &Tag{s: s} + if err := t.Decode(o); err != nil { + return nil, err + } + + return t, nil +} + +// ID returns the object ID of the tag, not the object that the tag references. +// The returned value will always match the current value of Tag.Hash. +// +// ID is present to fulfill the Object interface. +func (t *Tag) ID() plumbing.Hash { + return t.Hash +} + +// Type returns the type of object. It always returns plumbing.TagObject. +// +// Type is present to fulfill the Object interface. +func (t *Tag) Type() plumbing.ObjectType { + return plumbing.TagObject +} + +// Decode transforms a plumbing.EncodedObject into a Tag struct. +func (t *Tag) Decode(o plumbing.EncodedObject) (err error) { + if o.Type() != plumbing.TagObject { + return ErrUnsupportedObject + } + + t.Hash = o.Hash() + + reader, err := o.Reader() + if err != nil { + return err + } + defer ioutil.CheckClose(reader, &err) + + r := bufio.NewReader(reader) + for { + line, err := r.ReadSlice('\n') + if err != nil && err != io.EOF { + return err + } + + line = bytes.TrimSpace(line) + if len(line) == 0 { + break // Start of message + } + + split := bytes.SplitN(line, []byte{' '}, 2) + switch string(split[0]) { + case "object": + t.Target = plumbing.NewHash(string(split[1])) + case "type": + t.TargetType, err = plumbing.ParseObjectType(string(split[1])) + if err != nil { + return err + } + case "tag": + t.Name = string(split[1]) + case "tagger": + t.Tagger.Decode(split[1]) + } + + if err == io.EOF { + return nil + } + } + + data, err := stdioutil.ReadAll(r) + if err != nil { + return err + } + t.Message = string(data) + + return nil +} + +// Encode transforms a Tag into a plumbing.EncodedObject. +func (t *Tag) Encode(o plumbing.EncodedObject) error { + o.SetType(plumbing.TagObject) + w, err := o.Writer() + if err != nil { + return err + } + defer ioutil.CheckClose(w, &err) + + if _, err = fmt.Fprintf(w, + "object %s\ntype %s\ntag %s\ntagger ", + t.Target.String(), t.TargetType.Bytes(), t.Name); err != nil { + return err + } + + if err = t.Tagger.Encode(w); err != nil { + return err + } + + if _, err = fmt.Fprint(w, "\n\n"); err != nil { + return err + } + + if _, err = fmt.Fprint(w, t.Message); err != nil { + return err + } + + return err +} + +// Commit returns the commit pointed to by the tag. If the tag points to a +// different type of object ErrUnsupportedObject will be returned. +func (t *Tag) Commit() (*Commit, error) { + if t.TargetType != plumbing.CommitObject { + return nil, ErrUnsupportedObject + } + + o, err := t.s.EncodedObject(plumbing.CommitObject, t.Target) + if err != nil { + return nil, err + } + + return DecodeCommit(t.s, o) +} + +// Tree returns the tree pointed to by the tag. If the tag points to a commit +// object the tree of that commit will be returned. If the tag does not point +// to a commit or tree object ErrUnsupportedObject will be returned. +func (t *Tag) Tree() (*Tree, error) { + switch t.TargetType { + case plumbing.CommitObject: + c, err := t.Commit() + if err != nil { + return nil, err + } + + return c.Tree() + case plumbing.TreeObject: + return GetTree(t.s, t.Target) + default: + return nil, ErrUnsupportedObject + } +} + +// Blob returns the blob pointed to by the tag. If the tag points to a +// different type of object ErrUnsupportedObject will be returned. +func (t *Tag) Blob() (*Blob, error) { + if t.TargetType != plumbing.BlobObject { + return nil, ErrUnsupportedObject + } + + return GetBlob(t.s, t.Target) +} + +// Object returns the object pointed to by the tag. +func (t *Tag) Object() (Object, error) { + o, err := t.s.EncodedObject(t.TargetType, t.Target) + if err != nil { + return nil, err + } + + return DecodeObject(t.s, o) +} + +// String returns the meta information contained in the tag as a formatted +// string. +func (t *Tag) String() string { + obj, _ := t.Object() + + return fmt.Sprintf( + "%s %s\nTagger: %s\nDate: %s\n\n%s\n%s", + plumbing.TagObject, t.Name, t.Tagger.String(), t.Tagger.When.Format(DateFormat), + t.Message, objectAsString(obj), + ) +} + +// TagIter provides an iterator for a set of tags. +type TagIter struct { + storer.EncodedObjectIter + s storer.EncodedObjectStorer +} + +// NewTagIter returns a TagIter for the given object storer and underlying +// object iterator. +// +// The returned TagIter will automatically skip over non-tag objects. +func NewTagIter(s storer.EncodedObjectStorer, iter storer.EncodedObjectIter) *TagIter { + return &TagIter{iter, s} +} + +// Next moves the iterator to the next tag and returns a pointer to it. If it +// has reached the end of the set it will return io.EOF. +func (iter *TagIter) Next() (*Tag, error) { + obj, err := iter.EncodedObjectIter.Next() + if err != nil { + return nil, err + } + + return DecodeTag(iter.s, obj) +} + +// ForEach call the cb function for each tag contained on this iter until +// an error happends or the end of the iter is reached. If ErrStop is sent +// the iteration is stop but no error is returned. The iterator is closed. +func (iter *TagIter) ForEach(cb func(*Tag) error) error { + return iter.EncodedObjectIter.ForEach(func(obj plumbing.EncodedObject) error { + t, err := DecodeTag(iter.s, obj) + if err != nil { + return err + } + + return cb(t) + }) +} + +func objectAsString(obj Object) string { + switch o := obj.(type) { + case *Commit: + return o.String() + case *Tag: + return o.String() + } + + return "" +} |