forked from mirror/go-ethereum
parent
74de0f1f2a
commit
fb528c47c0
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package ethwire |
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import ( |
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"bytes" |
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"errors" |
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"fmt" |
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"net" |
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"time" |
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"github.com/ethereum/eth-go/ethutil" |
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) |
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// The connection object allows you to set up a connection to the Ethereum network.
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// The Connection object takes care of all encoding and sending objects properly over
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// the network.
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type Connection struct { |
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conn net.Conn |
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nTimeout time.Duration |
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pendingMessages Messages |
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} |
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// Create a new connection to the Ethereum network
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func New(conn net.Conn) *Connection { |
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return &Connection{conn: conn, nTimeout: 500} |
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} |
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// Read, reads from the network. It will block until the next message is received.
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func (self *Connection) Read() *Msg { |
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if len(self.pendingMessages) == 0 { |
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self.readMessages() |
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} |
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ret := self.pendingMessages[0] |
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self.pendingMessages = self.pendingMessages[1:] |
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return ret |
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} |
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// Write to the Ethereum network specifying the type of the message and
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// the data. Data can be of type RlpEncodable or []interface{}. Returns
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// nil or if something went wrong an error.
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func (self *Connection) Write(typ MsgType, v ...interface{}) error { |
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var pack []byte |
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slice := [][]interface{}{[]interface{}{byte(typ)}} |
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for _, value := range v { |
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if encodable, ok := value.(ethutil.RlpEncodeDecode); ok { |
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slice = append(slice, encodable.RlpValue()) |
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} else if raw, ok := value.([]interface{}); ok { |
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slice = append(slice, raw) |
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} else { |
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panic(fmt.Sprintf("Unable to 'write' object of type %T", value)) |
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} |
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} |
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// Encode the type and the (RLP encoded) data for sending over the wire
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encoded := ethutil.NewValue(slice).Encode() |
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payloadLength := ethutil.NumberToBytes(uint32(len(encoded)), 32) |
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// Write magic token and payload length (first 8 bytes)
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pack = append(MagicToken, payloadLength...) |
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pack = append(pack, encoded...) |
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// Write to the connection
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_, err := self.conn.Write(pack) |
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if err != nil { |
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return err |
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} |
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return nil |
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} |
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func (self *Connection) readMessage(data []byte) (msg *Msg, remaining []byte, done bool, err error) { |
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if len(data) == 0 { |
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return nil, nil, true, nil |
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} |
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if len(data) <= 8 { |
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return nil, remaining, false, errors.New("Invalid message") |
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} |
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// Check if the received 4 first bytes are the magic token
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if bytes.Compare(MagicToken, data[:4]) != 0 { |
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return nil, nil, false, fmt.Errorf("MagicToken mismatch. Received %v", data[:4]) |
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} |
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messageLength := ethutil.BytesToNumber(data[4:8]) |
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remaining = data[8+messageLength:] |
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if int(messageLength) > len(data[8:]) { |
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return nil, nil, false, fmt.Errorf("message length %d, expected %d", len(data[8:]), messageLength) |
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} |
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message := data[8 : 8+messageLength] |
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decoder := ethutil.NewValueFromBytes(message) |
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// Type of message
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t := decoder.Get(0).Uint() |
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// Actual data
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d := decoder.SliceFrom(1) |
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msg = &Msg{ |
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Type: MsgType(t), |
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Data: d, |
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} |
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return |
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} |
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// The basic message reader waits for data on the given connection, decoding
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// and doing a few sanity checks such as if there's a data type and
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// unmarhals the given data
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func (self *Connection) readMessages() (err error) { |
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// The recovering function in case anything goes horribly wrong
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defer func() { |
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if r := recover(); r != nil { |
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err = fmt.Errorf("ethwire.ReadMessage error: %v", r) |
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} |
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}() |
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// Buff for writing network message to
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//buff := make([]byte, 1440)
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var buff []byte |
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var totalBytes int |
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for { |
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// Give buffering some time
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self.conn.SetReadDeadline(time.Now().Add(self.nTimeout * time.Millisecond)) |
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// Create a new temporarily buffer
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b := make([]byte, 1440) |
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// Wait for a message from this peer
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n, _ := self.conn.Read(b) |
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if err != nil && n == 0 { |
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if err.Error() != "EOF" { |
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fmt.Println("err now", err) |
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return err |
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} else { |
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break |
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} |
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// Messages can't be empty
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} else if n == 0 { |
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break |
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} |
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buff = append(buff, b[:n]...) |
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totalBytes += n |
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} |
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// Reslice buffer
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buff = buff[:totalBytes] |
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msg, remaining, done, err := self.readMessage(buff) |
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for ; done != true; msg, remaining, done, err = self.readMessage(remaining) { |
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//log.Println("rx", msg)
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if msg != nil { |
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self.pendingMessages = append(self.pendingMessages, msg) |
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} |
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} |
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return |
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} |
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func ReadMessage(data []byte) (msg *Msg, remaining []byte, done bool, err error) { |
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if len(data) == 0 { |
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return nil, nil, true, nil |
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} |
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if len(data) <= 8 { |
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return nil, remaining, false, errors.New("Invalid message") |
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} |
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// Check if the received 4 first bytes are the magic token
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if bytes.Compare(MagicToken, data[:4]) != 0 { |
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return nil, nil, false, fmt.Errorf("MagicToken mismatch. Received %v", data[:4]) |
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} |
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messageLength := ethutil.BytesToNumber(data[4:8]) |
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remaining = data[8+messageLength:] |
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if int(messageLength) > len(data[8:]) { |
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return nil, nil, false, fmt.Errorf("message length %d, expected %d", len(data[8:]), messageLength) |
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} |
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message := data[8 : 8+messageLength] |
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decoder := ethutil.NewValueFromBytes(message) |
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// Type of message
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t := decoder.Get(0).Uint() |
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// Actual data
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d := decoder.SliceFrom(1) |
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msg = &Msg{ |
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Type: MsgType(t), |
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Data: d, |
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} |
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return |
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} |
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func bufferedRead(conn net.Conn) ([]byte, error) { |
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return nil, nil |
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} |
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