mirror of https://github.com/jackc/pgx.git
102 lines
2.4 KiB
Go
102 lines
2.4 KiB
Go
package pgproto3
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import (
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"bytes"
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"encoding/binary"
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"encoding/json"
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)
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const (
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TextFormat = 0
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BinaryFormat = 1
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)
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type FieldDescription struct {
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Name string
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TableOID uint32
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TableAttributeNumber uint16
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DataTypeOID uint32
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DataTypeSize int16
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TypeModifier uint32
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Format int16
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}
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type RowDescription struct {
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Fields []FieldDescription
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}
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func (*RowDescription) Backend() {}
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func (dst *RowDescription) Decode(src []byte) error {
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buf := bytes.NewBuffer(src)
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if buf.Len() < 2 {
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return &invalidMessageFormatErr{messageType: "RowDescription"}
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}
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fieldCount := int(binary.BigEndian.Uint16(buf.Next(2)))
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*dst = RowDescription{Fields: make([]FieldDescription, fieldCount)}
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for i := 0; i < fieldCount; i++ {
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var fd FieldDescription
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bName, err := buf.ReadBytes(0)
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if err != nil {
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return err
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}
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fd.Name = string(bName[:len(bName)-1])
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// Since buf.Next() doesn't return an error if we hit the end of the buffer
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// check Len ahead of time
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if buf.Len() < 18 {
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return &invalidMessageFormatErr{messageType: "RowDescription"}
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}
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fd.TableOID = binary.BigEndian.Uint32(buf.Next(4))
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fd.TableAttributeNumber = binary.BigEndian.Uint16(buf.Next(2))
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fd.DataTypeOID = binary.BigEndian.Uint32(buf.Next(4))
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fd.DataTypeSize = int16(binary.BigEndian.Uint16(buf.Next(2)))
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fd.TypeModifier = binary.BigEndian.Uint32(buf.Next(4))
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fd.Format = int16(binary.BigEndian.Uint16(buf.Next(2)))
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dst.Fields[i] = fd
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}
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return nil
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}
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func (src *RowDescription) MarshalBinary() ([]byte, error) {
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var bigEndian BigEndianBuf
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buf := &bytes.Buffer{}
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buf.WriteByte('T')
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buf.Write(bigEndian.Uint32(0))
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buf.Write(bigEndian.Uint16(uint16(len(src.Fields))))
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for _, fd := range src.Fields {
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buf.WriteString(fd.Name)
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buf.WriteByte(0)
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buf.Write(bigEndian.Uint32(fd.TableOID))
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buf.Write(bigEndian.Uint16(fd.TableAttributeNumber))
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buf.Write(bigEndian.Uint32(fd.DataTypeOID))
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buf.Write(bigEndian.Uint16(uint16(fd.DataTypeSize)))
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buf.Write(bigEndian.Uint32(fd.TypeModifier))
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buf.Write(bigEndian.Uint16(uint16(fd.Format)))
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}
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binary.BigEndian.PutUint32(buf.Bytes()[1:5], uint32(buf.Len()-1))
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return buf.Bytes(), nil
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}
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func (src *RowDescription) MarshalJSON() ([]byte, error) {
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return json.Marshal(struct {
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Type string
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Fields []FieldDescription
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}{
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Type: "RowDescription",
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Fields: src.Fields,
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})
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}
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