gtsocial-umbx

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copy_out_response.go (2387B)

      1 package pgproto3
      2 
      3 import (
      4 	"bytes"
      5 	"encoding/binary"
      6 	"encoding/json"
      7 	"errors"
      8 
      9 	"github.com/jackc/pgio"
     10 )
     11 
     12 type CopyOutResponse struct {
     13 	OverallFormat     byte
     14 	ColumnFormatCodes []uint16
     15 }
     16 
     17 func (*CopyOutResponse) Backend() {}
     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 *CopyOutResponse) Decode(src []byte) error {
     22 	buf := bytes.NewBuffer(src)
     23 
     24 	if buf.Len() < 3 {
     25 		return &invalidMessageFormatErr{messageType: "CopyOutResponse"}
     26 	}
     27 
     28 	overallFormat := buf.Next(1)[0]
     29 
     30 	columnCount := int(binary.BigEndian.Uint16(buf.Next(2)))
     31 	if buf.Len() != columnCount*2 {
     32 		return &invalidMessageFormatErr{messageType: "CopyOutResponse"}
     33 	}
     34 
     35 	columnFormatCodes := make([]uint16, columnCount)
     36 	for i := 0; i < columnCount; i++ {
     37 		columnFormatCodes[i] = binary.BigEndian.Uint16(buf.Next(2))
     38 	}
     39 
     40 	*dst = CopyOutResponse{OverallFormat: overallFormat, ColumnFormatCodes: columnFormatCodes}
     41 
     42 	return nil
     43 }
     44 
     45 // Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
     46 func (src *CopyOutResponse) Encode(dst []byte) []byte {
     47 	dst = append(dst, 'H')
     48 	sp := len(dst)
     49 	dst = pgio.AppendInt32(dst, -1)
     50 
     51 	dst = append(dst, src.OverallFormat)
     52 
     53 	dst = pgio.AppendUint16(dst, uint16(len(src.ColumnFormatCodes)))
     54 	for _, fc := range src.ColumnFormatCodes {
     55 		dst = pgio.AppendUint16(dst, fc)
     56 	}
     57 
     58 	pgio.SetInt32(dst[sp:], int32(len(dst[sp:])))
     59 
     60 	return dst
     61 }
     62 
     63 // MarshalJSON implements encoding/json.Marshaler.
     64 func (src CopyOutResponse) MarshalJSON() ([]byte, error) {
     65 	return json.Marshal(struct {
     66 		Type              string
     67 		ColumnFormatCodes []uint16
     68 	}{
     69 		Type:              "CopyOutResponse",
     70 		ColumnFormatCodes: src.ColumnFormatCodes,
     71 	})
     72 }
     73 
     74 // UnmarshalJSON implements encoding/json.Unmarshaler.
     75 func (dst *CopyOutResponse) UnmarshalJSON(data []byte) error {
     76 	// Ignore null, like in the main JSON package.
     77 	if string(data) == "null" {
     78 		return nil
     79 	}
     80 
     81 	var msg struct {
     82 		OverallFormat     string
     83 		ColumnFormatCodes []uint16
     84 	}
     85 	if err := json.Unmarshal(data, &msg); err != nil {
     86 		return err
     87 	}
     88 
     89 	if len(msg.OverallFormat) != 1 {
     90 		return errors.New("invalid length for CopyOutResponse.OverallFormat")
     91 	}
     92 
     93 	dst.OverallFormat = msg.OverallFormat[0]
     94 	dst.ColumnFormatCodes = msg.ColumnFormatCodes
     95 	return nil
     96 }