build source

vendor/github.com/jackc/pgx/v5/pgproto3/cancel_request.go

@@ -0,0 +1,85 @@
+package pgproto3
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+
+	"github.com/jackc/pgx/v5/internal/pgio"
+)
+
+const cancelRequestCode = 80877102
+
+type CancelRequest struct {
+	ProcessID uint32
+	SecretKey []byte
+}
+
+// Frontend identifies this message as sendable by a PostgreSQL frontend.
+func (*CancelRequest) Frontend() {}
+
+func (dst *CancelRequest) Decode(src []byte) error {
+	if len(src) < 12 {
+		return errors.New("cancel request too short")
+	}
+	if len(src) > 264 {
+		return errors.New("cancel request too long")
+	}
+
+	requestCode := binary.BigEndian.Uint32(src)
+	if requestCode != cancelRequestCode {
+		return errors.New("bad cancel request code")
+	}
+
+	dst.ProcessID = binary.BigEndian.Uint32(src[4:])
+	dst.SecretKey = make([]byte, len(src)-8)
+	copy(dst.SecretKey, src[8:])
+
+	return nil
+}
+
+// Encode encodes src into dst. dst will include the 4 byte message length.
+func (src *CancelRequest) Encode(dst []byte) ([]byte, error) {
+	if len(src.SecretKey) > 256 {
+		return nil, errors.New("secret key too long")
+	}
+	msgLen := int32(12 + len(src.SecretKey))
+	dst = pgio.AppendInt32(dst, msgLen)
+	dst = pgio.AppendInt32(dst, cancelRequestCode)
+	dst = pgio.AppendUint32(dst, src.ProcessID)
+	dst = append(dst, src.SecretKey...)
+	return dst, nil
+}
+
+// MarshalJSON implements encoding/json.Marshaler.
+func (src CancelRequest) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Type      string
+		ProcessID uint32
+		SecretKey string
+	}{
+		Type:      "CancelRequest",
+		ProcessID: src.ProcessID,
+		SecretKey: hex.EncodeToString(src.SecretKey),
+	})
+}
+
+// UnmarshalJSON implements encoding/json.Unmarshaler.
+func (dst *CancelRequest) UnmarshalJSON(data []byte) error {
+	var msg struct {
+		ProcessID uint32
+		SecretKey string
+	}
+	if err := json.Unmarshal(data, &msg); err != nil {
+		return err
+	}
+
+	dst.ProcessID = msg.ProcessID
+	secretKey, err := hex.DecodeString(msg.SecretKey)
+	if err != nil {
+		return err
+	}
+	dst.SecretKey = secretKey
+	return nil
+}