gtsocial-umbx

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copy_in_response.go (2449B)

      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 CopyInResponse struct {
     13 	OverallFormat     byte
     14 	ColumnFormatCodes []uint16
     15 }
     16 
     17 // Backend identifies this message as sendable by the PostgreSQL backend.
     18 func (*CopyInResponse) 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 *CopyInResponse) Decode(src []byte) error {
     23 	buf := bytes.NewBuffer(src)
     24 
     25 	if buf.Len() < 3 {
     26 		return &invalidMessageFormatErr{messageType: "CopyInResponse"}
     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: "CopyInResponse"}
     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 = CopyInResponse{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 *CopyInResponse) Encode(dst []byte) []byte {
     48 	dst = append(dst, 'G')
     49 	sp := len(dst)
     50 	dst = pgio.AppendInt32(dst, -1)
     51 
     52 	dst = append(dst, src.OverallFormat)
     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 CopyInResponse) MarshalJSON() ([]byte, error) {
     65 	return json.Marshal(struct {
     66 		Type              string
     67 		ColumnFormatCodes []uint16
     68 	}{
     69 		Type:              "CopyInResponse",
     70 		ColumnFormatCodes: src.ColumnFormatCodes,
     71 	})
     72 }
     73 
     74 // UnmarshalJSON implements encoding/json.Unmarshaler.
     75 func (dst *CopyInResponse) 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 CopyInResponse.OverallFormat")
     91 	}
     92 
     93 	dst.OverallFormat = msg.OverallFormat[0]
     94 	dst.ColumnFormatCodes = msg.ColumnFormatCodes
     95 	return nil
     96 }