diff options
Diffstat (limited to 'wire/messages2.go')
-rw-r--r-- | wire/messages2.go | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/wire/messages2.go b/wire/messages2.go new file mode 100644 index 000000000..acbd9e0d5 --- /dev/null +++ b/wire/messages2.go @@ -0,0 +1,199 @@ +package wire + +import ( + "bytes" + "errors" + "fmt" + "net" + "time" + + "github.com/ethereum/go-ethereum/ethutil" +) + +// The connection object allows you to set up a connection to the Ethereum network. +// The Connection object takes care of all encoding and sending objects properly over +// the network. +type Connection struct { + conn net.Conn + nTimeout time.Duration + pendingMessages Messages +} + +// Create a new connection to the Ethereum network +func New(conn net.Conn) *Connection { + return &Connection{conn: conn, nTimeout: 500} +} + +// Read, reads from the network. It will block until the next message is received. +func (self *Connection) Read() *Msg { + if len(self.pendingMessages) == 0 { + self.readMessages() + } + + ret := self.pendingMessages[0] + self.pendingMessages = self.pendingMessages[1:] + + return ret + +} + +// Write to the Ethereum network specifying the type of the message and +// the data. Data can be of type RlpEncodable or []interface{}. Returns +// nil or if something went wrong an error. +func (self *Connection) Write(typ MsgType, v ...interface{}) error { + var pack []byte + + slice := [][]interface{}{[]interface{}{byte(typ)}} + for _, value := range v { + if encodable, ok := value.(ethutil.RlpEncodeDecode); ok { + slice = append(slice, encodable.RlpValue()) + } else if raw, ok := value.([]interface{}); ok { + slice = append(slice, raw) + } else { + panic(fmt.Sprintf("Unable to 'write' object of type %T", value)) + } + } + + // Encode the type and the (RLP encoded) data for sending over the wire + encoded := ethutil.NewValue(slice).Encode() + payloadLength := ethutil.NumberToBytes(uint32(len(encoded)), 32) + + // Write magic token and payload length (first 8 bytes) + pack = append(MagicToken, payloadLength...) + pack = append(pack, encoded...) + + // Write to the connection + _, err := self.conn.Write(pack) + if err != nil { + return err + } + + return nil +} + +func (self *Connection) readMessage(data []byte) (msg *Msg, remaining []byte, done bool, err error) { + if len(data) == 0 { + return nil, nil, true, nil + } + + if len(data) <= 8 { + return nil, remaining, false, errors.New("Invalid message") + } + + // Check if the received 4 first bytes are the magic token + if bytes.Compare(MagicToken, data[:4]) != 0 { + return nil, nil, false, fmt.Errorf("MagicToken mismatch. Received %v", data[:4]) + } + + messageLength := ethutil.BytesToNumber(data[4:8]) + remaining = data[8+messageLength:] + if int(messageLength) > len(data[8:]) { + return nil, nil, false, fmt.Errorf("message length %d, expected %d", len(data[8:]), messageLength) + } + + message := data[8 : 8+messageLength] + decoder := ethutil.NewValueFromBytes(message) + // Type of message + t := decoder.Get(0).Uint() + // Actual data + d := decoder.SliceFrom(1) + + msg = &Msg{ + Type: MsgType(t), + Data: d, + } + + return +} + +// The basic message reader waits for data on the given connection, decoding +// and doing a few sanity checks such as if there's a data type and +// unmarhals the given data +func (self *Connection) readMessages() (err error) { + // The recovering function in case anything goes horribly wrong + defer func() { + if r := recover(); r != nil { + err = fmt.Errorf("wire.ReadMessage error: %v", r) + } + }() + + // Buff for writing network message to + //buff := make([]byte, 1440) + var buff []byte + var totalBytes int + for { + // Give buffering some time + self.conn.SetReadDeadline(time.Now().Add(self.nTimeout * time.Millisecond)) + // Create a new temporarily buffer + b := make([]byte, 1440) + // Wait for a message from this peer + n, _ := self.conn.Read(b) + if err != nil && n == 0 { + if err.Error() != "EOF" { + fmt.Println("err now", err) + return err + } else { + break + } + + // Messages can't be empty + } else if n == 0 { + break + } + + buff = append(buff, b[:n]...) + totalBytes += n + } + + // Reslice buffer + buff = buff[:totalBytes] + msg, remaining, done, err := self.readMessage(buff) + for ; done != true; msg, remaining, done, err = self.readMessage(remaining) { + //log.Println("rx", msg) + + if msg != nil { + self.pendingMessages = append(self.pendingMessages, msg) + } + } + + return +} + +func ReadMessage(data []byte) (msg *Msg, remaining []byte, done bool, err error) { + if len(data) == 0 { + return nil, nil, true, nil + } + + if len(data) <= 8 { + return nil, remaining, false, errors.New("Invalid message") + } + + // Check if the received 4 first bytes are the magic token + if bytes.Compare(MagicToken, data[:4]) != 0 { + return nil, nil, false, fmt.Errorf("MagicToken mismatch. Received %v", data[:4]) + } + + messageLength := ethutil.BytesToNumber(data[4:8]) + remaining = data[8+messageLength:] + if int(messageLength) > len(data[8:]) { + return nil, nil, false, fmt.Errorf("message length %d, expected %d", len(data[8:]), messageLength) + } + + message := data[8 : 8+messageLength] + decoder := ethutil.NewValueFromBytes(message) + // Type of message + t := decoder.Get(0).Uint() + // Actual data + d := decoder.SliceFrom(1) + + msg = &Msg{ + Type: MsgType(t), + Data: d, + } + + return +} + +func bufferedRead(conn net.Conn) ([]byte, error) { + return nil, nil +} |