REBASE!

protocol/messages.go

@@ -0,0 +1,106 @@
+package protocol
+
+import "io"
+
+type request struct {
+	name   string
+	offset uint64
+	size   uint32
+	hash   []byte
+}
+
+type header struct {
+	version int
+	msgID   int
+	msgType int
+}
+
+func encodeHeader(h header) uint32 {
+	return uint32(h.version&0xf)<<28 +
+		uint32(h.msgID&0xfff)<<16 +
+		uint32(h.msgType&0xff)<<8
+}
+
+func decodeHeader(u uint32) header {
+	return header{
+		version: int(u>>28) & 0xf,
+		msgID:   int(u>>16) & 0xfff,
+		msgType: int(u>>8) & 0xff,
+	}
+}
+
+func (w *marshalWriter) writeHeader(h header) {
+	w.writeUint32(encodeHeader(h))
+}
+
+func (w *marshalWriter) writeIndex(idx []FileInfo) {
+	w.writeUint32(uint32(len(idx)))
+	for _, f := range idx {
+		w.writeString(f.Name)
+		w.writeUint32(f.Flags)
+		w.writeUint64(uint64(f.Modified))
+		w.writeUint32(uint32(len(f.Blocks)))
+		for _, b := range f.Blocks {
+			w.writeUint32(b.Length)
+			w.writeBytes(b.Hash)
+		}
+	}
+}
+
+func WriteIndex(w io.Writer, idx []FileInfo) (int, error) {
+	mw := marshalWriter{w, 0, nil}
+	mw.writeIndex(idx)
+	return mw.tot, mw.err
+}
+
+func (w *marshalWriter) writeRequest(r request) {
+	w.writeString(r.name)
+	w.writeUint64(r.offset)
+	w.writeUint32(r.size)
+	w.writeBytes(r.hash)
+}
+
+func (w *marshalWriter) writeResponse(data []byte) {
+	w.writeBytes(data)
+}
+
+func (r *marshalReader) readHeader() header {
+	return decodeHeader(r.readUint32())
+}
+
+func (r *marshalReader) readIndex() []FileInfo {
+	nfiles := r.readUint32()
+	files := make([]FileInfo, nfiles)
+	for i := range files {
+		files[i].Name = r.readString()
+		files[i].Flags = r.readUint32()
+		files[i].Modified = int64(r.readUint64())
+		nblocks := r.readUint32()
+		blocks := make([]BlockInfo, nblocks)
+		for j := range blocks {
+			blocks[j].Length = r.readUint32()
+			blocks[j].Hash = r.readBytes()
+		}
+		files[i].Blocks = blocks
+	}
+	return files
+}
+
+func ReadIndex(r io.Reader) ([]FileInfo, error) {
+	mr := marshalReader{r, 0, nil}
+	idx := mr.readIndex()
+	return idx, mr.err
+}
+
+func (r *marshalReader) readRequest() request {
+	var req request
+	req.name = r.readString()
+	req.offset = r.readUint64()
+	req.size = r.readUint32()
+	req.hash = r.readBytes()
+	return req
+}
+
+func (r *marshalReader) readResponse() []byte {
+	return r.readBytes()
+}