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/*
* Copyright 2016-2019 The OpenZipkin Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package brave.opentracing;
import brave.Tracer;
import brave.propagation.ExtraFieldPropagation;
import io.opentracing.Span;
import io.opentracing.tag.Tags;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
/**
* Holds the {@linkplain brave.Span} used by the underlying {@linkplain brave.Tracer}.
*
* This type also includes hooks to integrate with the underlying {@linkplain brave.Tracer}. Ex
* you can access the underlying span with {@link #unwrap}
*
*
Operations to add data to the span are ignored once {@link #finish()} or {@link
* #finish(long)} are called.
*/
public final class BraveSpan implements Span {
private final Tracer tracer;
/** Prevents late adding data to a span */
volatile boolean finishCalled;
/** Reference invalidated when sampling priority set to 0, which can happen on any thread */
volatile brave.Span delegate;
volatile String remoteIpV4, remoteIpV6;
volatile int remotePort;
// tracer is only needed because the sampling.priority flag is used as a sampling api
BraveSpan(brave.Tracer tracer, brave.Span delegate) {
this.tracer = tracer;
if (delegate == null) throw new NullPointerException("delegate == null");
this.delegate = delegate;
}
/**
* Returns wrapped {@linkplain brave.Span}
*/
public final brave.Span unwrap() {
return delegate;
}
@Override public BraveSpanContext context() {
return BraveSpanContext.create(delegate.context());
}
@Override public BraveSpan setTag(String key, String value) {
if (finishCalled) return this;
if (trySetPeer(delegate, key, value)) return this;
if (trySetKind(key, value)) return this;
delegate.tag(key, value);
return this;
}
@Override public BraveSpan setTag(String key, boolean value) {
if (finishCalled) return this;
if (Tags.ERROR.getKey().equals(key) && !value) return this;
return setTag(key, Boolean.toString(value));
}
/**
* Note:If the key is {@linkplain Tags#SAMPLING_PRIORITY} and the value is zero, the
* current span will be abandoned and future references to the {@link #context()} will be
* unsampled. This does not affect the active span, nor does it affect any equivalent instances of
* this object. This is a best efforts means to handle late sampling decisions.
*/
@Override public BraveSpan setTag(String key, Number value) {
if (finishCalled) return this;
if (trySetPeer(key, value)) return this;
// handle late sampling decision
if (Tags.SAMPLING_PRIORITY.getKey().equals(key) && value.intValue() == 0) {
delegate.abandon();
// convert the span to no-op
delegate = tracer.toSpan(delegate.context().toBuilder().sampled(false).build());
}
return setTag(key, value.toString());
}
@Override public BraveSpan setTag(io.opentracing.tag.Tag tag, T value) {
// Strange there's a new api only to dispatch something that can be done as easily directly
// eg instead of tag.set(span, value) this allows span.setTag(tag, value) (3 more characters!)
// Would be nice to see documentation clarify why this was important enough to break api over.
tag.set(this, value);
return this;
}
@Override public BraveSpan log(Map fields) {
if (finishCalled) return this;
if (fields.isEmpty()) return this;
return log(toAnnotation(fields));
}
@Override public BraveSpan log(long timestampMicroseconds, Map fields) {
if (finishCalled) return this;
if (fields.isEmpty()) return this;
// in real life, do like zipkin-go-opentracing: "key1=value1 key2=value2"
return log(timestampMicroseconds, toAnnotation(fields));
}
@Override public BraveSpan log(String event) {
if (finishCalled) return this;
delegate.annotate(event);
return this;
}
@Override public BraveSpan log(long timestampMicroseconds, String event) {
if (finishCalled) return this;
delegate.annotate(timestampMicroseconds, event);
return this;
}
/** This is a NOOP unless {@link ExtraFieldPropagation} is in use */
@Override public BraveSpan setBaggageItem(String key, String value) {
ExtraFieldPropagation.set(delegate.context(), key, value);
return this;
}
/** Returns null unless {@link ExtraFieldPropagation} is in use */
@Override public String getBaggageItem(String key) {
return ExtraFieldPropagation.get(delegate.context(), key);
}
@Override public BraveSpan setOperationName(String operationName) {
if (finishCalled) return this;
delegate.name(operationName);
return this;
}
@Override public void finish() {
if (finishCalled) return;
finishCalled = true;
trySetRemoteIpAndPort();
delegate.finish();
}
@Override public void finish(long finishMicros) {
if (finishCalled) return;
finishCalled = true;
trySetRemoteIpAndPort();
delegate.finish(finishMicros);
}
/**
* Converts a map to a string of form: "key1=value1 key2=value2"
*/
static String toAnnotation(Map fields) {
// special-case the "event" field which is similar to the semantics of a zipkin annotation
Object event = fields.get("event");
if (event != null && fields.size() == 1) return event.toString();
return joinOnEqualsSpace(fields);
}
static String joinOnEqualsSpace(Map fields) {
if (fields.isEmpty()) return "";
StringBuilder result = new StringBuilder();
for (Iterator> i = fields.entrySet().iterator(); i.hasNext(); ) {
Map.Entry next = i.next();
result.append(next.getKey()).append('=').append(next.getValue());
if (i.hasNext()) result.append(' ');
}
return result.toString();
}
boolean trySetKind(String key, String value) {
if (!Tags.SPAN_KIND.getKey().equals(key)) return false;
if (Tags.SPAN_KIND_CLIENT.equals(value)) {
delegate.kind(brave.Span.Kind.CLIENT);
} else if (Tags.SPAN_KIND_SERVER.equals(value)) {
delegate.kind(brave.Span.Kind.SERVER);
} else if (Tags.SPAN_KIND_PRODUCER.equals(value)) {
delegate.kind(brave.Span.Kind.PRODUCER);
} else if (Tags.SPAN_KIND_CONSUMER.equals(value)) {
delegate.kind(brave.Span.Kind.CONSUMER);
} else {
return false;
}
return true;
}
boolean trySetPeer(brave.Span span, String key, String value) {
if (Tags.PEER_SERVICE.getKey().equals(key)) {
span.remoteServiceName(value);
} else if (Tags.PEER_HOST_IPV4.getKey().equals(key)) {
remoteIpV4 = value;
} else if (Tags.PEER_HOST_IPV6.getKey().equals(key)) {
remoteIpV6 = value;
} else {
return false;
}
return true;
}
boolean trySetPeer(String key, Number value) {
if (Tags.PEER_HOST_IPV4.getKey().equals(key)) {
int ipv4 = value.intValue();
remoteIpV4 = new StringBuilder()
.append(ipv4 >> 24 & 0xff).append('.')
.append(ipv4 >> 16 & 0xff).append('.')
.append(ipv4 >> 8 & 0xff).append('.')
.append(ipv4 & 0xff).toString();
} else if (Tags.PEER_PORT.getKey().equals(key)) {
remotePort = value.intValue();
} else {
return false;
}
return true;
}
void trySetRemoteIpAndPort() {
if (remoteIpV4 != null) delegate.remoteIpAndPort(remoteIpV4, remotePort);
if (remoteIpV6 != null) delegate.remoteIpAndPort(remoteIpV6, remotePort);
}
}