Golang Request.Method方法代碼示例

// processWriteIntentError tries to push the conflicting
// transaction(s) responsible for the given WriteIntentError, and to
// resolve those intents if possible. Returns a new error to be used
// in place of the original.
//
// The returned error may be a copy of the original WriteIntentError,
// with or without the Resolved flag set, which governs the client's
// retry behavior (if the transaction is pushed, the Resolved flag is
// set to tell the client to retry immediately; otherwise it is false
// to cause the client to back off).
func (ir *intentResolver) processWriteIntentError(ctx context.Context,
	wiPErr *roachpb.Error, args roachpb.Request, h roachpb.Header,
	pushType roachpb.PushTxnType) *roachpb.Error {
	wiErr, ok := wiPErr.GetDetail().(*roachpb.WriteIntentError)
	if !ok {
		return roachpb.NewErrorf("not a WriteIntentError: %v", wiPErr)
	}

	if log.V(6) {
		log.Infof(ctx, "resolving write intent %s", wiErr)
	}

	method := args.Method()
	readOnly := roachpb.IsReadOnly(args) // TODO(tschottdorf): pass as param

	resolveIntents, pushErr := ir.maybePushTransactions(ctx, wiErr.Intents, h, pushType, false)

	if resErr := ir.resolveIntents(ctx, resolveIntents,
		false /* !wait */, pushType == roachpb.PUSH_ABORT /* poison */); resErr != nil {
		// When resolving without waiting, errors should not
		// usually be returned here, although there are some cases
		// when they may be (especially when a test cluster is in
		// the process of shutting down).
		log.Warningf(ctx, "asynchronous resolveIntents failed: %s", resErr)
	}

	if pushErr != nil {
		if log.V(1) {
			log.Infof(ctx, "on %s: %s", method, pushErr)
		}

		if _, isExpected := pushErr.GetDetail().(*roachpb.TransactionPushError); !isExpected {
			// If an unexpected error occurred, make sure it bubbles up to the
			// client. Examples are timeouts and logic errors.
			return pushErr
		}

		// For write/write conflicts within a transaction, propagate the
		// push failure, not the original write intent error. The push
		// failure will instruct the client to restart the transaction
		// with a backoff.
		if h.Txn != nil && h.Txn.ID != nil && !readOnly {
			return pushErr
		}

		// For read/write conflicts, and non-transactional write/write
		// conflicts, return the write intent error which engages
		// backoff/retry (with !Resolved). We don't need to restart the
		// txn, only resend the read with a backoff.
		return wiPErr
	}

	// We pushed all transactions, so tell the client everything's
	// resolved and it can retry immediately.
	wiErr.Resolved = true
	return wiPErr // references wiErr
}

// processWriteIntentError tries to push the conflicting
// transaction(s) responsible for the given WriteIntentError, and to
// resolve those intents if possible. Returns a new error to be used
// in place of the original.
//
// The returned error may be a copy of the original WriteIntentError,
// with or without the Resolved flag set, which governs the client's
// retry behavior (if the transaction is pushed, the Resolved flag is
// set to tell the client to retry immediately; otherwise it is false
// to cause the client to back off).
func (ir *intentResolver) processWriteIntentError(ctx context.Context,
	wiErr roachpb.WriteIntentError, r *Replica, args roachpb.Request, h roachpb.Header,
	pushType roachpb.PushTxnType) *roachpb.Error {

	if log.V(6) {
		log.Infoc(ctx, "resolving write intent %s", wiErr)
	}

	method := args.Method()
	readOnly := roachpb.IsReadOnly(args) // TODO(tschottdorf): pass as param

	resolveIntents, pushErr := ir.maybePushTransactions(ctx, wiErr.Intents, h, pushType, false)

	if resErr := ir.resolveIntents(ctx, r, resolveIntents,
		false /* !wait */, true /* poison */); resErr != nil {
		// When resolving without waiting, errors should not
		// usually be returned here, although there are some cases
		// when they may be (especially when a test cluster is in
		// the process of shutting down).
		log.Warningf("asynchronous resolveIntents failed: %s", resErr)
	}

	if pushErr != nil {
		if log.V(1) {
			log.Infoc(ctx, "on %s: %s", method, pushErr)
		}

		// For write/write conflicts within a transaction, propagate the
		// push failure, not the original write intent error. The push
		// failure will instruct the client to restart the transaction
		// with a backoff.
		if h.Txn != nil && h.Txn.ID != nil && !readOnly {
			return pushErr
		}

		// For read/write conflicts, and non-transactional write/write
		// conflicts, return the write intent error which engages
		// backoff/retry (with !Resolved). We don't need to restart the
		// txn, only resend the read with a backoff.
		return roachpb.NewError(&wiErr)
	}

	// We pushed all transactions, so tell the client everything's
	// resolved and it can retry immediately.
	wiErr.Resolved = true
	return roachpb.NewError(&wiErr)
}