execute.go (1414B)
1 package pgproto3 2 3 import ( 4 "bytes" 5 "encoding/binary" 6 "encoding/json" 7 8 "github.com/jackc/pgio" 9 ) 10 11 type Execute struct { 12 Portal string 13 MaxRows uint32 14 } 15 16 // Frontend identifies this message as sendable by a PostgreSQL frontend. 17 func (*Execute) Frontend() {} 18 19 // Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message 20 // type identifier and 4 byte message length. 21 func (dst *Execute) Decode(src []byte) error { 22 buf := bytes.NewBuffer(src) 23 24 b, err := buf.ReadBytes(0) 25 if err != nil { 26 return err 27 } 28 dst.Portal = string(b[:len(b)-1]) 29 30 if buf.Len() < 4 { 31 return &invalidMessageFormatErr{messageType: "Execute"} 32 } 33 dst.MaxRows = binary.BigEndian.Uint32(buf.Next(4)) 34 35 return nil 36 } 37 38 // Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length. 39 func (src *Execute) Encode(dst []byte) []byte { 40 dst = append(dst, 'E') 41 sp := len(dst) 42 dst = pgio.AppendInt32(dst, -1) 43 44 dst = append(dst, src.Portal...) 45 dst = append(dst, 0) 46 47 dst = pgio.AppendUint32(dst, src.MaxRows) 48 49 pgio.SetInt32(dst[sp:], int32(len(dst[sp:]))) 50 51 return dst 52 } 53 54 // MarshalJSON implements encoding/json.Marshaler. 55 func (src Execute) MarshalJSON() ([]byte, error) { 56 return json.Marshal(struct { 57 Type string 58 Portal string 59 MaxRows uint32 60 }{ 61 Type: "Execute", 62 Portal: src.Portal, 63 MaxRows: src.MaxRows, 64 }) 65 }