package codec import ( "encoding/json" "fmt" "net" "time" "github.com/ethereum/go-ethereum/rpc/shared" ) const ( READ_TIMEOUT = 15 // read timeout in seconds MAX_REQUEST_SIZE = 1024 * 1024 MAX_RESPONSE_SIZE = 1024 * 1024 ) // Json serialization support type JsonCodec struct { c net.Conn } // Create new JSON coder instance func NewJsonCoder(conn net.Conn) ApiCoder { return &JsonCodec{ c: conn, } } // Serialize obj to JSON and write it to conn func (self *JsonCodec) ReadRequest() (requests []*shared.Request, isBatch bool, err error) { bytesInBuffer := 0 buf := make([]byte, MAX_REQUEST_SIZE) deadline := time.Now().Add(READ_TIMEOUT * time.Second) if err := self.c.SetDeadline(deadline); err != nil { return nil, false, err } for { n, err := self.c.Read(buf[bytesInBuffer:]) if err != nil { self.c.Close() return nil, false, err } bytesInBuffer += n singleRequest := shared.Request{} err = json.Unmarshal(buf[:bytesInBuffer], &singleRequest) if err == nil { requests := make([]*shared.Request, 1) requests[0] = &singleRequest return requests, false, nil } requests = make([]*shared.Request, 0) err = json.Unmarshal(buf[:bytesInBuffer], &requests) if err == nil { return requests, true, nil } } self.c.Close() // timeout return nil, false, fmt.Errorf("Unable to read response") } func (self *JsonCodec) ReadResponse() (interface{}, error) { bytesInBuffer := 0 buf := make([]byte, MAX_RESPONSE_SIZE) deadline := time.Now().Add(READ_TIMEOUT * time.Second) if err := self.c.SetDeadline(deadline); err != nil { return nil, err } for { n, err := self.c.Read(buf[bytesInBuffer:]) if err != nil { return nil, err } bytesInBuffer += n var success shared.SuccessResponse if err = json.Unmarshal(buf[:bytesInBuffer], &success); err == nil { return success, nil } var failure shared.ErrorResponse if err = json.Unmarshal(buf[:bytesInBuffer], &failure); err == nil && failure.Error != nil { return failure, nil } } self.c.Close() return nil, fmt.Errorf("Unable to read response") } // Decode data func (self *JsonCodec) Decode(data []byte, msg interface{}) error { return json.Unmarshal(data, msg) } // Encode message func (self *JsonCodec) Encode(msg interface{}) ([]byte, error) { return json.Marshal(msg) } // Parse JSON data from conn to obj func (self *JsonCodec) WriteResponse(res interface{}) error { data, err := json.Marshal(res) if err != nil { self.c.Close() return err } bytesWritten := 0 for bytesWritten < len(data) { n, err := self.c.Write(data[bytesWritten:]) if err != nil { self.c.Close() return err } bytesWritten += n } return nil } // Close decoder and encoder func (self *JsonCodec) Close() { self.c.Close() }