add getstream command to download a stream from a peer

cmd/getstream.go

@@ -0,0 +1,71 @@
+package cmd
+
+import (
+	"io/ioutil"
+	"os"
+
+	"github.com/lbryio/lbry.go/stream"
+
+	"github.com/lbryio/lbry.go/extras/errors"
+	"github.com/lbryio/reflector.go/peer"
+
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	var cmd = &cobra.Command{
+		Use:   "getstream ADDRESS:PORT SDHASH",
+		Short: "Get a stream from a reflector server",
+		Args:  cobra.ExactArgs(2),
+		Run:   getStreamCmd,
+	}
+	rootCmd.AddCommand(cmd)
+}
+
+func getStreamCmd(cmd *cobra.Command, args []string) {
+	addr := args[0]
+	sdHash := args[1]
+
+	c := peer.Client{}
+	err := c.Connect(addr)
+	if err != nil {
+		log.Fatal("error connecting client to server: ", err)
+	}
+
+	s, err := c.GetStream(sdHash)
+	if err != nil {
+		log.Error(errors.FullTrace(err))
+		return
+	}
+
+	var sd stream.SDBlob
+	err = sd.FromBlob(s[0])
+	if err != nil {
+		log.Error(errors.FullTrace(err))
+		return
+	}
+
+	log.Printf("Downloading %d blobs for %s", len(sd.BlobInfos)-1, sd.SuggestedFileName)
+
+	data, err := s.Data()
+	if err != nil {
+		log.Error(errors.FullTrace(err))
+		return
+	}
+
+	wd, err := os.Getwd()
+	if err != nil {
+		log.Error(errors.FullTrace(err))
+		return
+	}
+
+	filename := wd + "/" + sd.SuggestedFileName
+	err = ioutil.WriteFile(filename, data, 0644)
+	if err != nil {
+		log.Error(errors.FullTrace(err))
+		return
+	}
+
+	log.Printf("Wrote %d bytes to %s\n", len(data), filename)
+}

cmd/peer.go

@@ -14,23 +14,32 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var peerNoDB bool
+
 func init() {
 	var cmd = &cobra.Command{
 		Use:   "peer",
 		Short: "Run peer server",
 		Run:   peerCmd,
 	}
+	cmd.Flags().BoolVar(&peerNoDB, "nodb", false, "Don't connect to a db and don't use a db-backed blob store")
 	rootCmd.AddCommand(cmd)
 }
 
 func peerCmd(cmd *cobra.Command, args []string) {
-	db := new(db.SQL)
-	err := db.Connect(globalConfig.DBConn)
-	checkErr(err)
+	var err error
 
 	s3 := store.NewS3BlobStore(globalConfig.AwsID, globalConfig.AwsSecret, globalConfig.BucketRegion, globalConfig.BucketName)
+	peerServer := peer.NewServer(s3)
+
+	if !peerNoDB {
+		db := new(db.SQL)
+		err = db.Connect(globalConfig.DBConn)
+		checkErr(err)
+
 		combo := store.NewDBBackedS3Store(s3, db)
-	peerServer := peer.NewServer(combo)
+		peerServer = peer.NewServer(combo)
+	}
 
 	err = peerServer.Start(":" + strconv.Itoa(peer.DefaultPort))
 	if err != nil {

peer/client.go

@@ -0,0 +1,164 @@
+package peer
+
+import (
+	"bufio"
+	"encoding/hex"
+	"encoding/json"
+	"io"
+	"net"
+	"time"
+
+	"github.com/lbryio/lbry.go/stream"
+
+	"github.com/lbryio/lbry.go/extras/errors"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// ErrBlobExists is a default error for when a blob already exists on the reflector server.
+var ErrBlobExists = errors.Base("blob exists on server")
+
+// Client is an instance of a client connected to a server.
+type Client struct {
+	Timeout   time.Duration
+	conn      net.Conn
+	buf       *bufio.Reader
+	connected bool
+}
+
+// Connect connects to a specific clients and errors if it cannot be contacted.
+func (c *Client) Connect(address string) error {
+	var err error
+	if c.Timeout == 0 {
+		c.Timeout = 5 * time.Second
+	}
+	c.conn, err = net.Dial("tcp4", address)
+	if err != nil {
+		return err
+	}
+	c.connected = true
+	c.buf = bufio.NewReader(c.conn)
+	return nil
+}
+
+// Close closes the connection with the client.
+func (c *Client) Close() error {
+	c.connected = false
+	return c.conn.Close()
+}
+
+// GetStream gets a stream
+func (c *Client) GetStream(sdHash string) (stream.Stream, error) {
+	if !c.connected {
+		return nil, errors.Err("not connected")
+	}
+
+	var sd stream.SDBlob
+
+	b, err := c.GetBlob(sdHash)
+	if err != nil {
+		return nil, err
+	}
+
+	err = sd.FromBlob(b)
+	if err != nil {
+		return nil, err
+	}
+
+	s := make(stream.Stream, len(sd.BlobInfos)+1-1) // +1 for sd blob, -1 for last null blob
+	s[0] = b
+
+	for i := 0; i < len(sd.BlobInfos)-1; i++ {
+		s[i+1], err = c.GetBlob(hex.EncodeToString(sd.BlobInfos[i].BlobHash))
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return s, nil
+}
+
+// GetBlob gets a blob
+func (c *Client) GetBlob(blobHash string) (stream.Blob, error) {
+	if !c.connected {
+		return nil, errors.Err("not connected")
+	}
+
+	sendRequest, err := json.Marshal(blobRequest{
+		RequestedBlob: blobHash,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	err = c.write(sendRequest)
+	if err != nil {
+		return nil, err
+	}
+
+	var resp blobResponse
+	err = c.read(&resp)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.IncomingBlob.Error != "" {
+		return nil, errors.Prefix(blobHash[:8], resp.IncomingBlob.Error)
+	}
+	if resp.IncomingBlob.BlobHash != blobHash {
+		return nil, errors.Prefix(blobHash[:8], "Blob hash in response does not match requested hash")
+	}
+	if resp.IncomingBlob.Length <= 0 {
+		return nil, errors.Prefix(blobHash[:8], "Length reported as <= 0")
+	}
+
+	log.Println("Receiving blob " + blobHash[:8])
+
+	blob, err := c.readRawBlob(resp.IncomingBlob.Length)
+	if err != nil {
+		return nil, err
+	}
+
+	return stream.Blob(blob), nil
+}
+
+func (c *Client) read(v interface{}) error {
+	err := c.conn.SetReadDeadline(time.Now().Add(c.Timeout))
+	if err != nil {
+		return errors.Err(err)
+	}
+
+	m, err := readNextMessage(c.buf)
+	if err != nil {
+		return err
+	}
+
+	err = json.Unmarshal(m, v)
+	return errors.Err(err)
+}
+
+func (c *Client) readRawBlob(blobSize int) ([]byte, error) {
+	err := c.conn.SetReadDeadline(time.Now().Add(c.Timeout))
+	if err != nil {
+		return nil, errors.Err(err)
+	}
+
+	blob := make([]byte, blobSize)
+	_, err = io.ReadFull(c.buf, blob)
+	return blob, errors.Err(err)
+}
+
+func (c *Client) write(b []byte) error {
+	err := c.conn.SetWriteDeadline(time.Now().Add(c.Timeout))
+	if err != nil {
+		return errors.Err(err)
+	}
+
+	log.Debugf("Writing %d bytes", len(b))
+
+	n, err := c.conn.Write(b)
+	if err == nil && n != len(b) {
+		err = io.ErrShortWrite
+	}
+	return errors.Err(err)
+}

peer/server.go

@@ -112,6 +112,7 @@ func (s *Server) handleConnection(conn net.Conn) {
 	}()
 
 	timeoutDuration := 1 * time.Minute
+	buf := bufio.NewReader(conn)
 
 	for {
 		var request []byte
@@ -122,7 +123,7 @@ func (s *Server) handleConnection(conn net.Conn) {
 			log.Error(errors.FullTrace(err))
 		}
 
-		request, err = readNextRequest(conn)
+		request, err = readNextMessage(buf)
 		if err != nil {
 			if err != io.EOF {
 				s.logError(err)
@@ -314,10 +315,9 @@ func (s *Server) logError(e error) {
 	//log.Error(errors.FullTrace(e))
 }
 
-func readNextRequest(conn net.Conn) ([]byte, error) {
+func readNextMessage(buf *bufio.Reader) ([]byte, error) {
 	request := make([]byte, 0)
 	eof := false
-	buf := bufio.NewReader(conn)
 
 	for {
 		chunk, err := buf.ReadBytes('}')