89 lines
2.7 KiB
Go
89 lines
2.7 KiB
Go
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package node
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import (
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"fmt"
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)
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// ProtocolError represents an error from the remote peer.
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type ProtocolError struct {
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Code int
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Message string
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}
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func (e *ProtocolError) Error() string {
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return fmt.Sprintf("remote error (%d): %s", e.Code, e.Message)
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}
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// ResponseHandler provides helpers for handling protocol responses.
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type ResponseHandler struct{}
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// ValidateResponse checks if the response is valid and returns a parsed error if it's an error response.
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// It checks:
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// 1. If response is nil (returns error)
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// 2. If response is an error message (returns ProtocolError)
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// 3. If response type matches expected (returns error if not)
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func (h *ResponseHandler) ValidateResponse(resp *Message, expectedType MessageType) error {
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if resp == nil {
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return fmt.Errorf("nil response")
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}
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// Check for error response
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if resp.Type == MsgError {
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var errPayload ErrorPayload
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if err := resp.ParsePayload(&errPayload); err != nil {
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return &ProtocolError{Code: ErrCodeUnknown, Message: "unable to parse error response"}
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}
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return &ProtocolError{Code: errPayload.Code, Message: errPayload.Message}
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}
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// Check expected type
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if resp.Type != expectedType {
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return fmt.Errorf("unexpected response type: expected %s, got %s", expectedType, resp.Type)
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}
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return nil
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}
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// ParseResponse validates the response and parses the payload into the target.
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// This combines ValidateResponse and ParsePayload into a single call.
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func (h *ResponseHandler) ParseResponse(resp *Message, expectedType MessageType, target interface{}) error {
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if err := h.ValidateResponse(resp, expectedType); err != nil {
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return err
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}
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if target != nil {
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if err := resp.ParsePayload(target); err != nil {
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return fmt.Errorf("failed to parse %s payload: %w", expectedType, err)
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}
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}
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return nil
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}
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// DefaultResponseHandler is the default response handler instance.
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var DefaultResponseHandler = &ResponseHandler{}
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// ValidateResponse is a convenience function using the default handler.
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func ValidateResponse(resp *Message, expectedType MessageType) error {
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return DefaultResponseHandler.ValidateResponse(resp, expectedType)
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}
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// ParseResponse is a convenience function using the default handler.
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func ParseResponse(resp *Message, expectedType MessageType, target interface{}) error {
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return DefaultResponseHandler.ParseResponse(resp, expectedType, target)
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}
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// IsProtocolError returns true if the error is a ProtocolError.
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func IsProtocolError(err error) bool {
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_, ok := err.(*ProtocolError)
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return ok
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}
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// GetProtocolErrorCode returns the error code if err is a ProtocolError, otherwise returns 0.
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func GetProtocolErrorCode(err error) int {
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if pe, ok := err.(*ProtocolError); ok {
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return pe.Code
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}
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return 0
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}
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