RFC: provide insight into the status of gogit

options.go

@@ -133,7 +133,8 @@ type FetchOptions struct {
 	Progress sideband.Progress
 	// Tags describe how the tags will be fetched from the remote repository,
 	// by default is TagFollowing.
-	Tags TagFetchMode
+	Tags       TagFetchMode
+	StatusChan plumbing.StatusChan
 }
 
 // Validate validates the fields and sets the default values.
@@ -159,7 +160,8 @@ type PushOptions struct {
 	// object. A refspec with empty src can be used to delete a reference.
 	RefSpecs []config.RefSpec
 	// Auth credentials, if required, to use with the remote repository.
-	Auth transport.AuthMethod
+	Auth       transport.AuthMethod
+	StatusChan plumbing.StatusChan
 }
 
 // Validate validates the fields and sets the default values.

plumbing/format/idxfile/encoder.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"sort"
 
+	"gopkg.in/src-d/go-git.v4/plumbing"
 	"gopkg.in/src-d/go-git.v4/utils/binary"
 )
 
@@ -23,10 +24,10 @@ func NewEncoder(w io.Writer) *Encoder {
 }
 
 // Encode encodes an Idxfile to the encoder writer.
-func (e *Encoder) Encode(idx *Idxfile) (int, error) {
+func (e *Encoder) Encode(idx *Idxfile, statusChan plumbing.StatusChan) (int, error) {
 	idx.Entries.Sort()
 
-	flow := []func(*Idxfile) (int, error){
+	flow := []func(*Idxfile, plumbing.StatusChan) (int, error){
 		e.encodeHeader,
 		e.encodeFanout,
 		e.encodeHashes,
@@ -37,7 +38,7 @@ func (e *Encoder) Encode(idx *Idxfile) (int, error) {
 
 	sz := 0
 	for _, f := range flow {
-		i, err := f(idx)
+		i, err := f(idx, statusChan)
 		sz += i
 
 		if err != nil {
@@ -48,7 +49,7 @@ func (e *Encoder) Encode(idx *Idxfile) (int, error) {
 	return sz, nil
 }
 
-func (e *Encoder) encodeHeader(idx *Idxfile) (int, error) {
+func (e *Encoder) encodeHeader(idx *Idxfile, _ plumbing.StatusChan) (int, error) {
 	c, err := e.Write(idxHeader)
 	if err != nil {
 		return c, err
@@ -57,7 +58,7 @@ func (e *Encoder) encodeHeader(idx *Idxfile) (int, error) {
 	return c + 4, binary.WriteUint32(e, idx.Version)
 }
 
-func (e *Encoder) encodeFanout(idx *Idxfile) (int, error) {
+func (e *Encoder) encodeFanout(idx *Idxfile, _ plumbing.StatusChan) (int, error) {
 	fanout := idx.calculateFanout()
 	for _, c := range fanout {
 		if err := binary.WriteUint32(e, c); err != nil {
@@ -68,7 +69,13 @@ func (e *Encoder) encodeFanout(idx *Idxfile) (int, error) {
 	return 1024, nil
 }
 
-func (e *Encoder) encodeHashes(idx *Idxfile) (int, error) {
+func (e *Encoder) encodeHashes(idx *Idxfile, statusChan plumbing.StatusChan) (int, error) {
+	update := plumbing.StatusUpdate{
+		Stage:        plumbing.StatusIndexHash,
+		ObjectsTotal: len(idx.Entries),
+	}
+	statusChan.SendUpdate(update)
+
 	sz := 0
 	for _, ent := range idx.Entries {
 		i, err := e.Write(ent.Hash[:])
@@ -77,12 +84,20 @@ func (e *Encoder) encodeHashes(idx *Idxfile) (int, error) {
 		if err != nil {
 			return sz, err
 		}
+		update.ObjectsDone++
+		statusChan.SendUpdateIfPossible(update)
 	}
 
 	return sz, nil
 }
 
-func (e *Encoder) encodeCRC32(idx *Idxfile) (int, error) {
+func (e *Encoder) encodeCRC32(idx *Idxfile, statusChan plumbing.StatusChan) (int, error) {
+	update := plumbing.StatusUpdate{
+		Stage:        plumbing.StatusIndexCRC,
+		ObjectsTotal: len(idx.Entries),
+	}
+	statusChan.SendUpdate(update)
+
 	sz := 0
 	for _, ent := range idx.Entries {
 		err := binary.Write(e, ent.CRC32)
@@ -91,12 +106,20 @@ func (e *Encoder) encodeCRC32(idx *Idxfile) (int, error) {
 		if err != nil {
 			return sz, err
 		}
+		update.ObjectsDone++
+		statusChan.SendUpdateIfPossible(update)
 	}
 
 	return sz, nil
 }
 
-func (e *Encoder) encodeOffsets(idx *Idxfile) (int, error) {
+func (e *Encoder) encodeOffsets(idx *Idxfile, statusChan plumbing.StatusChan) (int, error) {
+	update := plumbing.StatusUpdate{
+		Stage:        plumbing.StatusIndexOffset,
+		ObjectsTotal: len(idx.Entries),
+	}
+	statusChan.SendUpdate(update)
+
 	sz := 0
 
 	var o64bits []uint64
@@ -112,6 +135,8 @@ func (e *Encoder) encodeOffsets(idx *Idxfile) (int, error) {
 		}
 
 		sz += 4
+		update.ObjectsDone++
+		statusChan.SendUpdateIfPossible(update)
 	}
 
 	for _, o := range o64bits {
@@ -125,7 +150,7 @@ func (e *Encoder) encodeOffsets(idx *Idxfile) (int, error) {
 	return sz, nil
 }
 
-func (e *Encoder) encodeChecksums(idx *Idxfile) (int, error) {
+func (e *Encoder) encodeChecksums(idx *Idxfile, _ plumbing.StatusChan) (int, error) {
 	if _, err := e.Write(idx.PackfileChecksum[:]); err != nil {
 		return 0, err
 	}

plumbing/format/packfile/common.go

@@ -3,6 +3,7 @@ package packfile
 import (
 	"io"
 
+	"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"
 )
@@ -23,9 +24,12 @@ const (
 
 // UpdateObjectStorage updates the given storer.EncodedObjectStorer with the contents of the
 // packfile.
-func UpdateObjectStorage(s storer.EncodedObjectStorer, packfile io.Reader) error {
+func UpdateObjectStorage(
+	s storer.EncodedObjectStorer,
+	packfile io.Reader,
+	statusChan plumbing.StatusChan) error {
 	if sw, ok := s.(storer.PackfileWriter); ok {
-		return writePackfileToObjectStorage(sw, packfile)
+		return writePackfileToObjectStorage(sw, packfile, statusChan)
 	}
 
 	stream := NewScanner(packfile)
@@ -34,13 +38,16 @@ func UpdateObjectStorage(s storer.EncodedObjectStorer, packfile io.Reader) error
 		return err
 	}
 
-	_, err = d.Decode()
+	_, err = d.Decode(statusChan)
 	return err
 }
 
-func writePackfileToObjectStorage(sw storer.PackfileWriter, packfile io.Reader) error {
+func writePackfileToObjectStorage(
+	sw storer.PackfileWriter,
+	packfile io.Reader,
+	statusChan plumbing.StatusChan) error {
 	var err error
-	w, err := sw.PackfileWriter()
+	w, err := sw.PackfileWriter(statusChan)
 	if err != nil {
 		return err
 	}

plumbing/format/packfile/decoder.go

@@ -116,26 +116,39 @@ func canResolveDeltas(s *Scanner, o storer.EncodedObjectStorer) bool {
 
 // Decode reads a packfile and stores it in the value pointed to by s. The
 // offsets and the CRCs are calculated by this method
-func (d *Decoder) Decode() (checksum plumbing.Hash, err error) {
+func (d *Decoder) Decode(statusChan plumbing.StatusChan) (checksum plumbing.Hash, err error) {
 	defer func() { d.isDecoded = true }()
 
 	if d.isDecoded {
 		return plumbing.ZeroHash, ErrAlreadyDecoded
 	}
 
-	if err := d.doDecode(); err != nil {
+	if err := d.doDecode(statusChan); err != nil {
 		return plumbing.ZeroHash, err
 	}
 
 	return d.s.Checksum()
 }
 
-func (d *Decoder) doDecode() error {
+func (d *Decoder) doDecode(statusChan plumbing.StatusChan) error {
+	statusChan.SendUpdate(plumbing.StatusUpdate{
+		Stage: plumbing.StatusCount,
+	})
+
 	_, count, err := d.s.Header()
 	if err != nil {
 		return err
 	}
 
+	statusChan.SendUpdate(plumbing.StatusUpdate{
+		Stage:        plumbing.StatusCount,
+		ObjectsTotal: int(count),
+	})
+	statusChan.SendUpdate(plumbing.StatusUpdate{
+		Stage:        plumbing.StatusFetch,
+		ObjectsTotal: int(count),
+	})
+
 	if !d.hasBuiltIndex {
 		d.idx = NewIndex(int(count))
 	}
@@ -144,25 +157,35 @@ func (d *Decoder) doDecode() error {
 	_, isTxStorer := d.o.(storer.Transactioner)
 	switch {
 	case d.o == nil:
-		return d.decodeObjects(int(count))
+		return d.decodeObjects(int(count), statusChan)
 	case isTxStorer:
-		return d.decodeObjectsWithObjectStorerTx(int(count))
+		return d.decodeObjectsWithObjectStorerTx(int(count), statusChan)
 	default:
-		return d.decodeObjectsWithObjectStorer(int(count))
+		return d.decodeObjectsWithObjectStorer(int(count), statusChan)
 	}
 }
 
-func (d *Decoder) decodeObjects(count int) error {
+func (d *Decoder) decodeObjects(count int, statusChan plumbing.StatusChan) error {
+	update := plumbing.StatusUpdate{
+		Stage:        plumbing.StatusFetch,
+		ObjectsTotal: count,
+	}
 	for i := 0; i < count; i++ {
 		if _, err := d.DecodeObject(); err != nil {
 			return err
 		}
+		update.ObjectsDone++
+		statusChan.SendUpdateIfPossible(update)
 	}
 
 	return nil
 }
 
-func (d *Decoder) decodeObjectsWithObjectStorer(count int) error {
+func (d *Decoder) decodeObjectsWithObjectStorer(count int, statusChan plumbing.StatusChan) error {
+	update := plumbing.StatusUpdate{
+		Stage:        plumbing.StatusFetch,
+		ObjectsTotal: count,
+	}
 	for i := 0; i < count; i++ {
 		obj, err := d.DecodeObject()
 		if err != nil {
@@ -172,12 +195,19 @@ func (d *Decoder) decodeObjectsWithObjectStorer(count int) error {
 		if _, err := d.o.SetEncodedObject(obj); err != nil {
 			return err
 		}
+		update.ObjectsDone++
+		statusChan.SendUpdateIfPossible(update)
 	}
 
 	return nil
 }
 
-func (d *Decoder) decodeObjectsWithObjectStorerTx(count int) error {
+func (d *Decoder) decodeObjectsWithObjectStorerTx(count int, statusChan plumbing.StatusChan) error {
+	update := plumbing.StatusUpdate{
+		Stage:        plumbing.StatusFetch,
+		ObjectsTotal: count,
+	}
+
 	d.tx = d.o.(storer.Transactioner).Begin()
 
 	for i := 0; i < count; i++ {
@@ -196,6 +226,8 @@ func (d *Decoder) decodeObjectsWithObjectStorerTx(count int) error {
 			return err
 		}
 
+		update.ObjectsDone++
+		statusChan.SendUpdateIfPossible(update)
 	}
 
 	return d.tx.Commit()