Add incubator module with utilities for mutating SpanData. (#1625)

* Add incubator module with utilities for mutating SpanData.

* Finish

sdk_extensions/tracing_incubator/build.gradle

@@ -0,0 +1,23 @@
+plugins {
+    id "java"
+    id "maven-publish"
+
+    id "ru.vyarus.animalsniffer"
+}
+
+// SDK modules that are still being developed.
+
+description = 'OpenTelemetry SDK Tracing Incubator'
+ext.moduleName = "io.opentelemetry.sdk.extension.trace.incubator"
+
+dependencies {
+    api project(':opentelemetry-api'),
+            project(':opentelemetry-sdk')
+
+
+    annotationProcessor libraries.auto_value
+    testImplementation project(':opentelemetry-testing-internal')
+
+    signature "org.codehaus.mojo.signature:java17:1.0@signature"
+    signature "net.sf.androidscents.signature:android-api-level-24:7.0_r2@signature"
+}

sdk_extensions/tracing_incubator/src/main/java/io/opentelemetry/sdk/extensions/incubator/trace/data/DelegatingSpanData.java

@@ -0,0 +1,307 @@
+/*
+ * Copyright 2020, OpenTelemetry 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 io.opentelemetry.sdk.extensions.incubator.trace.data;
+
+import static java.util.Objects.requireNonNull;
+
+import io.opentelemetry.common.ReadableAttributes;
+import io.opentelemetry.sdk.common.InstrumentationLibraryInfo;
+import io.opentelemetry.sdk.resources.Resource;
+import io.opentelemetry.sdk.trace.data.SpanData;
+import io.opentelemetry.trace.Span.Kind;
+import io.opentelemetry.trace.Status;
+import io.opentelemetry.trace.TraceState;
+import java.util.List;
+
+/**
+ * A {@link SpanData} which delegates all methods to another {@link SpanData}. Extend this class to
+ * modify the {@link SpanData} that will be exported, for example by creating a delegating {@link
+ * io.opentelemetry.sdk.trace.export.SpanExporter} which wraps {@link SpanData} with a custom
+ * implementation.
+ *
+ * <pre>{@code
+ * SpanDataWithClientType extends DelegatingSpanData {
+ *
+ *   private final ReadableAttributes attributes;
+ *
+ *   SpanDataWithClientType(SpanData delegate) {
+ *     super(delegate);
+ *     String clientType = ClientConfig.parseUserAgent(
+ *       delegate.getAttributes().get(SemanticAttributes.HTTP_USER_AGENT).getStringValue());
+ *     Attributes.Builder newAttributes = Attributes.newBuilder(delegate.getAttributes());
+ *     newAttributes.setAttribute("client_type", clientType);
+ *     attributes = newAttributes.build();
+ *   }
+ *
+ *   {@literal @}Override
+ *   public ReadableAttributes getAttributes() {
+ *     return attributes;
+ *   }
+ * }
+ *
+ * }</pre>
+ */
+public abstract class DelegatingSpanData implements SpanData {
+
+  private final SpanData delegate;
+
+  protected DelegatingSpanData(SpanData delegate) {
+    this.delegate = requireNonNull(delegate, "delegate");
+  }
+
+  @Override
+  public String getTraceId() {
+    return delegate.getTraceId();
+  }
+
+  @Override
+  public String getSpanId() {
+    return delegate.getSpanId();
+  }
+
+  @Override
+  public boolean isSampled() {
+    return delegate.isSampled();
+  }
+
+  @Override
+  public TraceState getTraceState() {
+    return delegate.getTraceState();
+  }
+
+  @Override
+  public String getParentSpanId() {
+    return delegate.getParentSpanId();
+  }
+
+  @Override
+  public Resource getResource() {
+    return delegate.getResource();
+  }
+
+  @Override
+  public InstrumentationLibraryInfo getInstrumentationLibraryInfo() {
+    return delegate.getInstrumentationLibraryInfo();
+  }
+
+  @Override
+  public String getName() {
+    return delegate.getName();
+  }
+
+  @Override
+  public Kind getKind() {
+    return delegate.getKind();
+  }
+
+  @Override
+  public long getStartEpochNanos() {
+    return delegate.getStartEpochNanos();
+  }
+
+  @Override
+  public ReadableAttributes getAttributes() {
+    return delegate.getAttributes();
+  }
+
+  @Override
+  public List<Event> getEvents() {
+    return delegate.getEvents();
+  }
+
+  @Override
+  public List<Link> getLinks() {
+    return delegate.getLinks();
+  }
+
+  @Override
+  public Status getStatus() {
+    return delegate.getStatus();
+  }
+
+  @Override
+  public long getEndEpochNanos() {
+    return delegate.getEndEpochNanos();
+  }
+
+  @Override
+  public boolean getHasRemoteParent() {
+    return delegate.getHasRemoteParent();
+  }
+
+  @Override
+  public boolean getHasEnded() {
+    return delegate.getHasEnded();
+  }
+
+  @Override
+  public int getTotalRecordedEvents() {
+    return delegate.getTotalRecordedEvents();
+  }
+
+  @Override
+  public int getTotalRecordedLinks() {
+    return delegate.getTotalRecordedLinks();
+  }
+
+  @Override
+  public int getTotalAttributeCount() {
+    return delegate.getTotalAttributeCount();
+  }
+
+  @Override
+  public final boolean equals(Object o) {
+    if (o == this) {
+      return true;
+    }
+    if (o instanceof SpanData) {
+      SpanData that = (SpanData) o;
+      return getTraceId().equals(that.getTraceId())
+          && getSpanId().equals(that.getSpanId())
+          && isSampled() == that.isSampled()
+          && getTraceState().equals(that.getTraceState())
+          && getParentSpanId().equals(that.getParentSpanId())
+          && getResource().equals(that.getResource())
+          && getInstrumentationLibraryInfo().equals(that.getInstrumentationLibraryInfo())
+          && getName().equals(that.getName())
+          && getKind().equals(that.getKind())
+          && getStartEpochNanos() == that.getStartEpochNanos()
+          && getAttributes().equals(that.getAttributes())
+          && getEvents().equals(that.getEvents())
+          && getLinks().equals(that.getLinks())
+          && getStatus().equals(that.getStatus())
+          && getEndEpochNanos() == that.getEndEpochNanos()
+          && getHasRemoteParent() == that.getHasRemoteParent()
+          && getHasEnded() == that.getHasEnded()
+          && getTotalRecordedEvents() == that.getTotalRecordedEvents()
+          && getTotalRecordedLinks() == that.getTotalRecordedLinks()
+          && getTotalAttributeCount() == that.getTotalAttributeCount();
+    }
+    return false;
+  }
+
+  @Override
+  public int hashCode() {
+    int code = 1;
+    code *= 1000003;
+    code ^= getTraceId().hashCode();
+    code *= 1000003;
+    code ^= getSpanId().hashCode();
+    code *= 1000003;
+    code ^= getTraceId().hashCode();
+    code *= 1000003;
+    code ^= getTraceState().hashCode();
+    code *= 1000003;
+    code ^= getParentSpanId().hashCode();
+    code *= 1000003;
+    code ^= getResource().hashCode();
+    code *= 1000003;
+    code ^= getInstrumentationLibraryInfo().hashCode();
+    code *= 1000003;
+    code ^= getName().hashCode();
+    code *= 1000003;
+    code ^= getKind().hashCode();
+    code *= 1000003;
+    code ^= (int) ((getStartEpochNanos() >>> 32) ^ getStartEpochNanos());
+    code *= 1000003;
+    code ^= getAttributes().hashCode();
+    code *= 1000003;
+    code ^= getEvents().hashCode();
+    code *= 1000003;
+    code ^= getLinks().hashCode();
+    code *= 1000003;
+    code ^= getStatus().hashCode();
+    code *= 1000003;
+    code ^= (int) ((getEndEpochNanos() >>> 32) ^ getEndEpochNanos());
+    code *= 1000003;
+    code ^= getHasRemoteParent() ? 1231 : 1237;
+    code *= 1000003;
+    code ^= getHasEnded() ? 1231 : 1237;
+    code *= 1000003;
+    code ^= getTotalRecordedEvents();
+    code *= 1000003;
+    code ^= getTotalRecordedLinks();
+    code *= 1000003;
+    code ^= getTotalAttributeCount();
+    return code;
+  }
+
+  @Override
+  public String toString() {
+    return "SpanDataImpl{"
+        + "traceId="
+        + getTraceId()
+        + ", "
+        + "spanId="
+        + getSpanId()
+        + ", "
+        + "isSampled="
+        + isSampled()
+        + ", "
+        + "traceState="
+        + getTraceState()
+        + ", "
+        + "parentSpanId="
+        + getParentSpanId()
+        + ", "
+        + "resource="
+        + getResource()
+        + ", "
+        + "instrumentationLibraryInfo="
+        + getInstrumentationLibraryInfo()
+        + ", "
+        + "name="
+        + getName()
+        + ", "
+        + "kind="
+        + getKind()
+        + ", "
+        + "startEpochNanos="
+        + getStartEpochNanos()
+        + ", "
+        + "attributes="
+        + getAttributes()
+        + ", "
+        + "events="
+        + getEvents()
+        + ", "
+        + "links="
+        + getLinks()
+        + ", "
+        + "status="
+        + getStatus()
+        + ", "
+        + "endEpochNanos="
+        + getEndEpochNanos()
+        + ", "
+        + "hasRemoteParent="
+        + getHasRemoteParent()
+        + ", "
+        + "hasEnded="
+        + getHasEnded()
+        + ", "
+        + "totalRecordedEvents="
+        + getTotalRecordedEvents()
+        + ", "
+        + "totalRecordedLinks="
+        + getTotalRecordedLinks()
+        + ", "
+        + "totalAttributeCount="
+        + getTotalAttributeCount()
+        + "}";
+  }
+}