Initial commit

vendor/github.com/jackc/pgproto3/v2/parameter_description.go

@@ -0,0 +1,66 @@
+package pgproto3
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/json"
+
+	"github.com/jackc/pgio"
+)
+
+type ParameterDescription struct {
+	ParameterOIDs []uint32
+}
+
+// Backend identifies this message as sendable by the PostgreSQL backend.
+func (*ParameterDescription) Backend() {}
+
+// Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
+// type identifier and 4 byte message length.
+func (dst *ParameterDescription) Decode(src []byte) error {
+	buf := bytes.NewBuffer(src)
+
+	if buf.Len() < 2 {
+		return &invalidMessageFormatErr{messageType: "ParameterDescription"}
+	}
+
+	// Reported parameter count will be incorrect when number of args is greater than uint16
+	buf.Next(2)
+	// Instead infer parameter count by remaining size of message
+	parameterCount := buf.Len() / 4
+
+	*dst = ParameterDescription{ParameterOIDs: make([]uint32, parameterCount)}
+
+	for i := 0; i < parameterCount; i++ {
+		dst.ParameterOIDs[i] = binary.BigEndian.Uint32(buf.Next(4))
+	}
+
+	return nil
+}
+
+// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
+func (src *ParameterDescription) Encode(dst []byte) []byte {
+	dst = append(dst, 't')
+	sp := len(dst)
+	dst = pgio.AppendInt32(dst, -1)
+
+	dst = pgio.AppendUint16(dst, uint16(len(src.ParameterOIDs)))
+	for _, oid := range src.ParameterOIDs {
+		dst = pgio.AppendUint32(dst, oid)
+	}
+
+	pgio.SetInt32(dst[sp:], int32(len(dst[sp:])))
+
+	return dst
+}
+
+// MarshalJSON implements encoding/json.Marshaler.
+func (src ParameterDescription) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Type          string
+		ParameterOIDs []uint32
+	}{
+		Type:          "ParameterDescription",
+		ParameterOIDs: src.ParameterOIDs,
+	})
+}