reflector.go/reflector/client.go
2020-10-05 16:30:57 -04:00

155 lines
3.2 KiB
Go

package reflector
import (
"encoding/json"
"log"
"net"
"github.com/lbryio/lbry.go/v2/extras/errors"
"github.com/lbryio/lbry.go/v2/stream"
)
// 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 {
conn net.Conn
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
c.conn, err = net.Dial(network, address)
if err != nil {
return err
}
c.connected = true
return c.doHandshake(protocolVersion1)
}
// Close closes the connection with the client.
func (c *Client) Close() error {
c.connected = false
return c.conn.Close()
}
// SendBlob sends a blob to the server.
func (c *Client) SendBlob(blob stream.Blob) error {
return c.sendBlob(blob, false)
}
// SendSDBlob sends an SD blob request to the server.
func (c *Client) SendSDBlob(blob stream.Blob) error {
return c.sendBlob(blob, true)
}
// sendBlob does the actual blob sending
func (c *Client) sendBlob(blob stream.Blob, isSDBlob bool) error {
if !c.connected {
return errors.Err("not connected")
}
if err := blob.ValidForSend(); err != nil {
return errors.Err(err)
}
blobHash := blob.HashHex()
var req sendBlobRequest
if isSDBlob {
req.SdBlobSize = blob.Size()
req.SdBlobHash = blobHash
} else {
req.BlobSize = blob.Size()
req.BlobHash = blobHash
}
sendRequest, err := json.Marshal(req)
if err != nil {
return err
}
_, err = c.conn.Write(sendRequest)
if err != nil {
return err
}
dec := json.NewDecoder(c.conn)
if isSDBlob {
var sendResp sendSdBlobResponse
err = dec.Decode(&sendResp)
if err != nil {
return err
}
if !sendResp.SendSdBlob {
return errors.Prefix(blobHash[:8], ErrBlobExists)
}
log.Println("Sending SD blob " + blobHash[:8])
} else {
var sendResp sendBlobResponse
err = dec.Decode(&sendResp)
if err != nil {
return err
}
if !sendResp.SendBlob {
return errors.Prefix(blobHash[:8], ErrBlobExists)
}
log.Println("Sending blob " + blobHash[:8])
}
_, err = c.conn.Write(blob)
if err != nil {
return err
}
if isSDBlob {
var transferResp sdBlobTransferResponse
err = dec.Decode(&transferResp)
if err != nil {
return err
}
if !transferResp.ReceivedSdBlob {
return errors.Err("server did not received SD blob")
}
} else {
var transferResp blobTransferResponse
err = dec.Decode(&transferResp)
if err != nil {
return err
}
if !transferResp.ReceivedBlob {
return errors.Err("server did not received blob")
}
}
return nil
}
func (c *Client) doHandshake(version int) error {
if !c.connected {
return errors.Err("not connected")
}
handshake, err := json.Marshal(handshakeRequestResponse{Version: &version})
if err != nil {
return err
}
_, err = c.conn.Write(handshake)
if err != nil {
return err
}
var resp handshakeRequestResponse
err = json.NewDecoder(c.conn).Decode(&resp)
if err != nil {
return err
} else if resp.Version == nil {
return errors.Err("invalid handshake")
} else if *resp.Version != version {
return errors.Err("handshake version mismatch")
}
return nil
}