Add GoDoc comments

snapshot/snapshot.go

@@ -10,23 +10,27 @@ import (
 	"github.com/rqlite/rqlite/db"
 )
 
+// Snapshot represents a snapshot of the database state.
 type Snapshot struct {
 	walData []byte
 	files   []string
 }
 
+// NewWALSnapshot creates a new snapshot from a WAL.
 func NewWALSnapshot(b []byte) *Snapshot {
 	return &Snapshot{
 		walData: b,
 	}
 }
 
+// NewFullSnapshot creates a new snapshot from a SQLite file and WALs.
 func NewFullSnapshot(files ...string) *Snapshot {
 	return &Snapshot{
 		files: files,
 	}
 }
 
+// Persist writes the snapshot to the given sink.
 func (s *Snapshot) Persist(sink raft.SnapshotSink) error {
 	stream, err := s.OpenStream()
 	if err != nil {
@@ -38,8 +42,10 @@ func (s *Snapshot) Persist(sink raft.SnapshotSink) error {
 	return err
 }
 
+// Release is a no-op.
 func (s *Snapshot) Release() {}
 
+// OpenStream returns a stream for reading the snapshot.
 func (s *Snapshot) OpenStream() (*Stream, error) {
 	if len(s.files) > 0 {
 		return NewFullStream(s.files...)
@@ -47,6 +53,8 @@ func (s *Snapshot) OpenStream() (*Stream, error) {
 	return NewIncrementalStream(s.walData)
 }
 
+// ReplayDB reconstructs the database from the given reader, and writes it to
+// the given path.
 func ReplayDB(fullSnap *FullSnapshot, r io.Reader, path string) error {
 	dbInfo := fullSnap.GetDb()
 	if dbInfo == nil {

snapshot/stream.go

@@ -16,12 +16,14 @@ const (
 	streamVersion    = 1
 )
 
+// NewStreamHeader creates a new StreamHeader.
 func NewStreamHeader() *StreamHeader {
 	return &StreamHeader{
 		Version: streamVersion,
 	}
 }
 
+// NewStreamHeaderFromReader reads a StreamHeader from the given reader.
 func NewStreamHeaderFromReader(r io.Reader) (*StreamHeader, int64, error) {
 	var totalSizeRead int64
 
@@ -51,6 +53,7 @@ func NewStreamHeaderFromReader(r io.Reader) (*StreamHeader, int64, error) {
 	return strHdr, totalSizeRead, nil
 }
 
+// FileSize returns the total size of the files in the snapshot.
 func (s *StreamHeader) FileSize() int64 {
 	if fs := s.GetFullSnapshot(); fs != nil {
 		var size int64
@@ -63,6 +66,7 @@ func (s *StreamHeader) FileSize() int64 {
 	return 0
 }
 
+// Stream is a stream of data that can be read from a snapshot.
 type Stream struct {
 	headerLen int64
 
@@ -71,6 +75,8 @@ type Stream struct {
 	totalFileSize  int64
 }
 
+// NewIncrementalStream creates a new stream from a byte slice, presumably
+// representing WAL data.
 func NewIncrementalStream(data []byte) (*Stream, error) {
 	strHdr := NewStreamHeader()
 	strHdr.Payload = &StreamHeader_IncrementalSnapshot{
@@ -92,6 +98,8 @@ func NewIncrementalStream(data []byte) (*Stream, error) {
 	}, nil
 }
 
+// NewFullStream creates a new stream from a SQLite file and 0 or more
+// WAL files.
 func NewFullStream(files ...string) (*Stream, error) {
 	if len(files) == 0 {
 		return nil, errors.New("no files provided")
@@ -155,10 +163,13 @@ func NewFullStream(files ...string) (*Stream, error) {
 	}, nil
 }
 
+// Size returns the total number of bytes that will be read from the stream,
+// if the stream is fully read.
 func (s *Stream) Size() int64 {
 	return int64(strHeaderLenSize + int64(s.headerLen) + s.totalFileSize)
 }
 
+// Read reads from the stream.
 func (s *Stream) Read(p []byte) (n int, err error) {
 	if s.readClosersIdx >= len(s.readClosers) {
 		return 0, io.EOF
@@ -176,6 +187,7 @@ func (s *Stream) Read(p []byte) (n int, err error) {
 	return n, err
 }
 
+// Close closes the stream.
 func (s *Stream) Close() error {
 	for _, r := range s.readClosers {
 		if err := r.Close(); err != nil {