gtsocial-umbx

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copy_both_response.go (2470B)

      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 CopyBothResponse struct {
     13 	OverallFormat     byte
     14 	ColumnFormatCodes []uint16
     15 }
     16 
     17 // Backend identifies this message as sendable by the PostgreSQL backend.
     18 func (*CopyBothResponse) Backend() {}
     19 
     20 // Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
     21 // type identifier and 4 byte message length.
     22 func (dst *CopyBothResponse) Decode(src []byte) error {
     23 	buf := bytes.NewBuffer(src)
     24 
     25 	if buf.Len() < 3 {
     26 		return &invalidMessageFormatErr{messageType: "CopyBothResponse"}
     27 	}
     28 
     29 	overallFormat := buf.Next(1)[0]
     30 
     31 	columnCount := int(binary.BigEndian.Uint16(buf.Next(2)))
     32 	if buf.Len() != columnCount*2 {
     33 		return &invalidMessageFormatErr{messageType: "CopyBothResponse"}
     34 	}
     35 
     36 	columnFormatCodes := make([]uint16, columnCount)
     37 	for i := 0; i < columnCount; i++ {
     38 		columnFormatCodes[i] = binary.BigEndian.Uint16(buf.Next(2))
     39 	}
     40 
     41 	*dst = CopyBothResponse{OverallFormat: overallFormat, ColumnFormatCodes: columnFormatCodes}
     42 
     43 	return nil
     44 }
     45 
     46 // Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
     47 func (src *CopyBothResponse) Encode(dst []byte) []byte {
     48 	dst = append(dst, 'W')
     49 	sp := len(dst)
     50 	dst = pgio.AppendInt32(dst, -1)
     51 	dst = append(dst, src.OverallFormat)
     52 	dst = pgio.AppendUint16(dst, uint16(len(src.ColumnFormatCodes)))
     53 	for _, fc := range src.ColumnFormatCodes {
     54 		dst = pgio.AppendUint16(dst, fc)
     55 	}
     56 
     57 	pgio.SetInt32(dst[sp:], int32(len(dst[sp:])))
     58 
     59 	return dst
     60 }
     61 
     62 // MarshalJSON implements encoding/json.Marshaler.
     63 func (src CopyBothResponse) MarshalJSON() ([]byte, error) {
     64 	return json.Marshal(struct {
     65 		Type              string
     66 		ColumnFormatCodes []uint16
     67 	}{
     68 		Type:              "CopyBothResponse",
     69 		ColumnFormatCodes: src.ColumnFormatCodes,
     70 	})
     71 }
     72 
     73 // UnmarshalJSON implements encoding/json.Unmarshaler.
     74 func (dst *CopyBothResponse) UnmarshalJSON(data []byte) error {
     75 	// Ignore null, like in the main JSON package.
     76 	if string(data) == "null" {
     77 		return nil
     78 	}
     79 
     80 	var msg struct {
     81 		OverallFormat     string
     82 		ColumnFormatCodes []uint16
     83 	}
     84 	if err := json.Unmarshal(data, &msg); err != nil {
     85 		return err
     86 	}
     87 
     88 	if len(msg.OverallFormat) != 1 {
     89 		return errors.New("invalid length for CopyBothResponse.OverallFormat")
     90 	}
     91 
     92 	dst.OverallFormat = msg.OverallFormat[0]
     93 	dst.ColumnFormatCodes = msg.ColumnFormatCodes
     94 	return nil
     95 }