How to use

getCurrentSpanStackCopy

method

in

com.nike.wingtips.Tracer

/**
 * @return A *copy* of the current thread's tracing information. Since this creates copies of the span stack and MDC
 * info it can have a noticeable performance impact if used too many times (i.e. tens or hundreds of times per
 * request for high throughput services). NOTE: This is usually not needed unless you're doing asynchronous
 * processing and need to pass tracing state across thread boundaries.
 */
public TracingState getCurrentTracingStateCopy() {
  return new TracingState(getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

/**
 * Constructor that extracts the current tracing and MDC information from the current thread using {@link
 * Tracer#getCurrentSpanStackCopy()} and {@link MDC#getCopyOfContextMap()}, and forwards the information to
 * the {@link BiFunctionWithTracing#BiFunctionWithTracing(BiFunction, Deque, Map)}
 * constructor. That tracing and MDC information will be associated with the thread when the given operation is
 * executed.
 *
 * <p>The operation you pass in cannot be null (an {@link IllegalArgumentException} will be thrown if you pass in
 * null for the operation).
 */
public BiFunctionWithTracing(BiFunction<T, U, R> origBiFunction) {
  this(origBiFunction, Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

/**
 * Constructor that extracts the current tracing and MDC information from the current thread using {@link
 * Tracer#getCurrentSpanStackCopy()} and {@link MDC#getCopyOfContextMap()}, and forwards the information to
 * the {@link SupplierWithTracing#SupplierWithTracing(Supplier, Deque, Map)}
 * constructor. That tracing and MDC information will be associated with the thread when the given operation is
 * executed.
 *
 * <p>The operation you pass in cannot be null (an {@link IllegalArgumentException} will be thrown if you pass in
 * null for the operation).
 */
public SupplierWithTracing(Supplier<U> origSupplier) {
  this(origSupplier, Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

/**
 * Constructor that extracts the current tracing and MDC information from the current thread using {@link
 * Tracer#getCurrentSpanStackCopy()} and {@link MDC#getCopyOfContextMap()}, and forwards the information to
 * the {@link SuccessCallbackWithTracing#SuccessCallbackWithTracing(SuccessCallback, Deque, Map)}
 * constructor. That tracing and MDC information will be associated with the thread when the given operation is
 * executed.
 *
 * <p>The operation you pass in cannot be null (an {@link IllegalArgumentException} will be thrown if you pass in
 * null for the operation).
 */
public SuccessCallbackWithTracing(SuccessCallback<T> origSuccessCallback) {
  this(origSuccessCallback, Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

/**
 * Constructor that extracts the current tracing and MDC information from the current thread using {@link
 * Tracer#getCurrentSpanStackCopy()} and {@link MDC#getCopyOfContextMap()}, and forwards the information to
 * the {@link FailureCallbackWithTracing#FailureCallbackWithTracing(FailureCallback, Deque, Map)}
 * constructor. That tracing and MDC information will be associated with the thread when the given operation is
 * executed.
 * 
 * <p>The operation you pass in cannot be null (an {@link IllegalArgumentException} will be thrown if you pass in
 * null for the operation).
 */
public FailureCallbackWithTracing(FailureCallback origFailureCallback) {
  this(origFailureCallback, Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

/**
 * Constructor that extracts the current tracing and MDC information from the current thread using {@link
 * Tracer#getCurrentSpanStackCopy()} and {@link MDC#getCopyOfContextMap()}, and forwards the information to
 * the {@link ConsumerWithTracing#ConsumerWithTracing(Consumer, Deque, Map)}
 * constructor. That tracing and MDC information will be associated with the thread when the given operation is
 * executed.
 *
 * <p>The operation you pass in cannot be null (an {@link IllegalArgumentException} will be thrown if you pass in
 * null for the operation).
 */
public ConsumerWithTracing(Consumer<T> origConsumer) {
  this(origConsumer, Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

/**
 * Constructor that extracts the current tracing and MDC information from the current thread using {@link
 * Tracer#getCurrentSpanStackCopy()} and {@link MDC#getCopyOfContextMap()}, and forwards the information to
 * the {@link BiPredicateWithTracing#BiPredicateWithTracing(BiPredicate, Deque, Map)}
 * constructor. That tracing and MDC information will be associated with the thread when the given operation is
 * executed.
 *
 * <p>The operation you pass in cannot be null (an {@link IllegalArgumentException} will be thrown if you pass in
 * null for the operation).
 */
public BiPredicateWithTracing(BiPredicate<T, U> origBiPredicate) {
  this(origBiPredicate, Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

/**
 * Constructor that extracts the current tracing and MDC information from the current thread using {@link
 * Tracer#getCurrentSpanStackCopy()} and {@link MDC#getCopyOfContextMap()}, and forwards the information to
 * the {@link RunnableWithTracing#RunnableWithTracing(Runnable, Deque, Map)}
 * constructor. That tracing and MDC information will be associated with the thread when the given operation is
 * executed.
 * 
 * <p>The operation you pass in cannot be null (an {@link IllegalArgumentException} will be thrown if you pass in
 * null for the operation).
 */
public RunnableWithTracing(Runnable origRunnable) {
  this(origRunnable, Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

  @Override
  public Object answer(InvocationOnMock invocation) throws Throwable {
    currentSpanStackWhenCallableWasCalled.add(Tracer.getInstance().getCurrentSpanStackCopy());
    currentMdcInfoWhenCallableWasCalled.add(MDC.getCopyOfContextMap());
    if (throwExceptionDuringCall)
      throw new RuntimeException("kaboom");
    return null;
  }
}).when(callableMock).call();

  @Override
  public Object answer(InvocationOnMock invocation) throws Throwable {
    currentSpanStackWhenRunnableWasCalled.add(Tracer.getInstance().getCurrentSpanStackCopy());
    currentMdcInfoWhenRunnableWasCalled.add(MDC.getCopyOfContextMap());
    if (throwExceptionDuringCall)
      throw new RuntimeException("kaboom");
    return null;
  }
}).when(runnableMock).run();

@Test
public void getCurrentSpanStackCopy_returns_null_if_original_is_null() {
  // given
  Tracer tracer = Tracer.getInstance();
  assertThat(getSpanStackSize()).isEqualTo(0);
  // expect
  assertThat(tracer.getCurrentSpanStackCopy()).isNull();
}

@Test
public void linkTracingAndMdcToCurrentThread_should_clear_mdc_if_state_is_available_but_state_mdc_info_is_null() {
  // given
  MDC.put("foo", "bar");
  Tracer.getInstance().startRequestWithRootSpan("blahtrace");
  assertThat(MDC.getCopyOfContextMap().isEmpty(), is(false));
  assertThat(Tracer.getInstance().getCurrentSpan(), notNullValue());
  // when
  handler.linkTracingAndMdcToCurrentThread(ctxMock);
  // then
  assertThat(MDC.getCopyOfContextMap().isEmpty(), is(true));
  assertThat(Tracer.getInstance().getCurrentSpanStackCopy(), nullValue());
}

private Pair<Deque<Span>, Map<String, String>> setupCurrentThreadWithTracingInfo() {
  resetTracing();
  Tracer.getInstance().startRequestWithRootSpan("request-" + UUID.randomUUID().toString());
  return Pair.of(Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

private Pair<Deque<Span>, Map<String, String>> setupCurrentThreadWithTracingInfo() {
  resetTracing();
  Tracer.getInstance().startRequestWithRootSpan("request-" + UUID.randomUUID().toString());
  return Pair.of(Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

private Pair<Deque<Span>, Map<String, String>> setupCurrentThreadWithTracingInfo() {
  resetTracing();
  Tracer.getInstance().startRequestWithRootSpan("request-" + UUID.randomUUID().toString());
  return Pair.of(Tracer.getInstance().getCurrentSpanStackCopy(), MDC.getCopyOfContextMap());
}

public static ChannelHandlerContextMocks mockChannelHandlerContextWithTraceInfo(String userId) {
  if (Tracer.getInstance().getCurrentSpan() == null) {
    Tracer.getInstance().startRequestWithRootSpan("mockChannelHandlerContext", userId);
  }
  ChannelHandlerContextMocks channelHandlerMocks = mockChannelHandlerContext();
  when(channelHandlerMocks.mockHttpProcessingState.getLoggerMdcContextMap()).thenReturn(MDC.getCopyOfContextMap());
  when(channelHandlerMocks.mockHttpProcessingState.getDistributedTraceStack()).thenReturn(Tracer.getInstance().getCurrentSpanStackCopy());
  return channelHandlerMocks;
}

private Pair<Deque<Span>, Map<String, String>> generateTracingInfo() {
  resetTracing();
  Tracer.getInstance().startRequestWithRootSpan("someSpan");
  Pair<Deque<Span>, Map<String, String>> result = Pair.of(
    Tracer.getInstance().getCurrentSpanStackCopy(), new HashMap<>(MDC.getCopyOfContextMap())
  );
  resetTracing();
  return result;
}

private Pair<Deque<Span>, Map<String, String>> generateTracingInfo() {
  resetTracing();
  Tracer.getInstance().startRequestWithRootSpan("someSpan");
  Pair<Deque<Span>, Map<String, String>> result = Pair.of(
    Tracer.getInstance().getCurrentSpanStackCopy(), new HashMap<>(MDC.getCopyOfContextMap())
  );
  resetTracing();
  return result;
}

private Pair<Deque<Span>, Map<String, String>> generateTracingAndMdcInfo() {
  resetTracingAndMdc();
  Tracer.getInstance().startRequestWithRootSpan("someSpan");
  Pair<Deque<Span>, Map<String, String>> result = Pair.of(
    Tracer.getInstance().getCurrentSpanStackCopy(), new HashMap<>(MDC.getCopyOfContextMap())
  );
  resetTracingAndMdc();
  return result;
}

private Pair<Deque<Span>, Map<String, String>> generateTracingInfo() {
  resetTracing();
  Tracer.getInstance().startRequestWithRootSpan("someSpan");
  Pair<Deque<Span>, Map<String, String>> result = Pair.of(
    Tracer.getInstance().getCurrentSpanStackCopy(),
    (Map<String, String>)new HashMap<>(MDC.getCopyOfContextMap())
  );
  resetTracing();
  return result;
}