Package brave.propagation

Class TraceContext

java.lang.Object

brave.propagation.SamplingFlags

brave.propagation.TraceContext

public final class TraceContext
extends SamplingFlags

Contains trace identifiers and sampling data propagated in and out-of-process.

Particularly, this includes trace identifiers and sampled state.

The implementation was originally com.github.kristofa.brave.SpanId, which was a port of com.twitter.finagle.tracing.TraceId. Unlike these mentioned, this type does not expose a single binary representation. That's because propagation forms can now vary.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	TraceContext.Builder
static interface	TraceContext.Extractor<C>	Used to join an incoming trace.
static interface	TraceContext.Injector<C>	Used to send the trace context downstream.

Field Summary

Fields inherited from class brave.propagation.SamplingFlags

DEBUG, EMPTY, NOT_SAMPLED, SAMPLED

Method Summary

Modifier and Type	Method	Description
boolean	debug()	True is a request to store this span even if it overrides sampling policy.
boolean	equals(Object o)	Only includes mandatory fields traceIdHigh(), traceId(), spanId()
List<Object>	extra()	Returns a list of additional data propagated through this trace.
int	hashCode()	Only includes mandatory fields traceIdHigh(), traceId(), spanId()
static TraceContext.Builder	newBuilder()
Long	parentId()	The parent's spanId or null if this the root span in a trace.
long	parentIdAsLong()	Like parentId() except returns a primitive where zero implies absent.
Boolean	sampled()	Should we sample this request or not? True means sample, false means don't, null means we defer decision to someone further down in the stack.
boolean	shared()	Deprecated. it is unnecessary overhead to propagate this property
long	spanId()	Unique 8-byte identifier of this span within a trace.
TraceContext.Builder	toBuilder()
String	toString()	Returns $traceId/$spanId
long	traceId()	Unique 8-byte identifier for a trace, set on all spans within it.
long	traceIdHigh()	When non-zero, the trace containing this span uses 128-bit trace identifiers.
String	traceIdString()	Returns the hex representation of the span's trace ID

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

newBuilder

public static TraceContext.Builder newBuilder()

traceIdHigh

public long traceIdHigh()

When non-zero, the trace containing this span uses 128-bit trace identifiers.

traceId

public long traceId()

Unique 8-byte identifier for a trace, set on all spans within it.

parentId

@Nullable
public final Long parentId()

The parent's spanId or null if this the root span in a trace.

See Also:

parentIdAsLong()

parentIdAsLong

public long parentIdAsLong()

Like parentId() except returns a primitive where zero implies absent.

Using this method will avoid allocation, so is encouraged when copying data.

sampled

@Nullable
public Boolean sampled()

Should we sample this request or not? True means sample, false means don't, null means we defer decision to someone further down in the stack.

Specified by:

sampled in class SamplingFlags

debug

public boolean debug()

True is a request to store this span even if it overrides sampling policy. Defaults to false.

Specified by:

debug in class SamplingFlags

spanId

public long spanId()

Unique 8-byte identifier of this span within a trace.

A span is uniquely identified in storage by (traceId, spanId).

shared

@Deprecated
public final boolean shared()

Deprecated. it is unnecessary overhead to propagate this property

extra

public List<Object> extra()

Returns a list of additional data propagated through this trace.

The contents are intentionally opaque, deferring to Propagation to define. An example implementation could be storing a class containing a correlation value, which is extracted from incoming requests and injected as-is onto outgoing requests.

Implementations are responsible for scoping any data stored here. This can be performed when Propagation.Factory.decorate(TraceContext) is called.

toBuilder

public TraceContext.Builder toBuilder()

traceIdString

public String traceIdString()

Returns the hex representation of the span's trace ID

toString

public String toString()

Returns $traceId/$spanId

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Only includes mandatory fields traceIdHigh(), traceId(), spanId()

Overrides:

equals in class Object

hashCode

public int hashCode()

Only includes mandatory fields traceIdHigh(), traceId(), spanId()

Overrides:

hashCode in class Object