jqclient_3.go

// badTransformations keeps track of expr that resulted in the jqworker process
// getting killed.
//
// Need to set a TTL (or some eviction policy) on the map so its growth is deterministic.
var badTransformations = make(map[string]int)

// JqTransform runs transformation on the jqserver
func JqTransform(rpcClient *rpc.Client, input SomeInput) (*SomeOutput, error) {
	if badTransformations[params.Expression] == 3 {
		return nil, errors.New("skipping potential resource exhaustive transformation")
	}
	output := &SomeOutput{}
	err := rpcClient.Call("Jqserver.Evaluate", input, output)
	if err != nil {
		// errors.Is() don't work because
		//
		// https://pkg.go.dev/net/rpc#pkg-overview
		//
		// The method's return value, if non-nil, is passed back as a
		// string that the client sees as if created by errors.New. If an
		// error is returned, the reply parameter will not be sent back to
		// the client.
		if err.Error() == "resource limit exceeded" {
			badTransformations[params.Expression] += 1
		}
	}
	return output, err
}