Initial cut at moving Entity SDK to have correpsonding API.

- Creates an API matching EntityProvider OTEP
- Updates EntityDetector to be ResourceDetector
- Creates synchronous "update resource with this entity" method.
- Adds wiring for incubating API + incubating SDK

Note: Still have some thoughts and ideas about a formal API, this may still change.

Author: jsuereth

…extension/incubator/entities/Entity.java …metry/api/incubator/entities/Entity.javasdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/entities/Entity.java renamed to api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/Entity.java sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/entities/Entity.java renamed to api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/Entity.java

@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-package io.opentelemetry.sdk.extension.incubator.entities;
+package io.opentelemetry.api.incubator.entities;
 
 import io.opentelemetry.api.common.Attributes;
 import javax.annotation.Nullable;
@@ -59,13 +59,4 @@ public interface Entity {
    * Returns a new {@link EntityBuilder} instance populated with the data of this {@link Entity}.
    */
   EntityBuilder toBuilder();
-
-  /**
-   * Returns a new {@link EntityBuilder} instance for creating arbitrary {@link Entity}.
-   *
-   * @param entityType the entity type string of this entity.
-   */
-  public static EntityBuilder builder(String entityType) {
-    return PassthroughEntity.builder(entityType);
-  }
 }

…on/incubator/entities/EntityBuilder.java …pi/incubator/entities/EntityBuilder.javasdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/entities/EntityBuilder.java renamed to api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/EntityBuilder.java sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/entities/EntityBuilder.java renamed to api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/EntityBuilder.java

@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-package io.opentelemetry.sdk.extension.incubator.entities;
+package io.opentelemetry.api.incubator.entities;
 
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
@@ -25,15 +25,15 @@ public interface EntityBuilder {
   /**
    * Modify the descriptive attributes of this Entity.
    *
-   * @param f A thunk which manipulates descriptive attributes.
+   * @param f A {@link Consumer} which builds the descriptive attributes.
    * @return this
    */
   EntityBuilder withDescription(Consumer<AttributesBuilder> f);
 
   /**
    * Modify the identifying attributes of this Entity.
    *
-   * @param f A thunk which manipulates identifying attributes.
+   * @param f A {@link Consumer} which builds the identifying attributes.
    * @return this
    */
   EntityBuilder withId(Consumer<AttributesBuilder> f);

api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/ExtendedOpenTelemetry.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.api.incubator.entities;
+
+import io.opentelemetry.api.OpenTelemetry;
+
+/** Extension to {@link OpenTelemetry} that adds {@link ResourceProvider}. */
+public interface ExtendedOpenTelemetry extends OpenTelemetry {
+  /** Returns the {@link ResourceProvider} for this {@link OpenTelemetry}. */
+  default ResourceProvider getResourceProvider() {
+    return ResourceProvider.noop();
+  }
+
+  /** Returns the {@link Resource} that telemetry from this {@link OpenTelemetry} uses. */
+  default Resource getResource() {
+    return getResourceProvider().getResource();
+  }
+}

api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/NoopEntity.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.api.incubator.entities;
+
+import io.opentelemetry.api.common.Attributes;
+
+final class NoopEntity implements Entity {
+
+  @Override
+  public String getType() {
+    return "";
+  }
+
+  @Override
+  public Attributes getId() {
+    return Attributes.empty();
+  }
+
+  @Override
+  public Attributes getDescription() {
+    return Attributes.empty();
+  }
+
+  @Override
+  public String getSchemaUrl() {
+    return "";
+  }
+
+  @Override
+  public EntityBuilder toBuilder() {
+    return new NoopEntityBuilder();
+  }
+}

api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/NoopEntityBuilder.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.api.incubator.entities;
+
+import io.opentelemetry.api.common.AttributesBuilder;
+import java.util.function.Consumer;
+
+final class NoopEntityBuilder implements EntityBuilder {
+  @Override
+  public EntityBuilder setSchemaUrl(String schemaUrl) {
+    return this;
+  }
+
+  @Override
+  public EntityBuilder withDescription(Consumer<AttributesBuilder> f) {
+    return this;
+  }
+
+  @Override
+  public EntityBuilder withId(Consumer<AttributesBuilder> f) {
+    return this;
+  }
+
+  @Override
+  public Entity build() {
+    return new NoopEntity();
+  }
+}

api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/NoopResource.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.api.incubator.entities;
+
+final class NoopResource implements Resource {
+
+  @Override
+  public boolean addOrUpdate(Entity e) {
+    return false;
+  }
+
+  @Override
+  public boolean removeEntity(Entity e) {
+    return false;
+  }
+
+  @Override
+  public EntityBuilder createEntity(String entityType) {
+    return new NoopEntityBuilder();
+  }
+}

api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/NoopResourceProvider.java

@@ -0,0 +1,14 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.api.incubator.entities;
+
+final class NoopResourceProvider implements ResourceProvider {
+
+  @Override
+  public Resource getResource() {
+    return new NoopResource();
+  }
+}

api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/Resource.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.api.incubator.entities;
+
+/** The active resource for which Telemetry is being generated. */
+public interface Resource {
+  /**
+   * Adds an {@link Entity} to this resource.
+   *
+   * <p>If the entity already exists, this updates the description.
+   *
+   * @param e The entity
+   * @return true if the entity was added or updated, false if there was a conflict.
+   */
+  public boolean addOrUpdate(Entity e);
+
+  /**
+   * Removes an {@link Entity} from this resource.
+   *
+   * @param e The entity
+   * @return true if entity was found and removed.
+   */
+  public boolean removeEntity(Entity e);
+
+  /**
+   * Returns a builder that can construct an {@link Entity}.
+   *
+   * @param entityType The type of the entity.
+   * @return A builder that can construct an entity.
+   */
+  public EntityBuilder createEntity(String entityType);
+}

api/incubator/src/main/java/io/opentelemetry/api/incubator/entities/ResourceProvider.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.api.incubator.entities;
+
+/**
+ * A registry for interacting with {@link Resource}s. The name <i>Provider</i> is for consistency
+ * with other languages and it is <b>NOT</b> loaded using reflection.
+ *
+ * @see Resource
+ */
+public interface ResourceProvider {
+  /**
+   * Returns a no-op {@link ResourceProvider} which only creates no-op {@link Resource}s which do
+   * not record nor are emitted.
+   */
+  static ResourceProvider noop() {
+    return new NoopResourceProvider();
+  }
+
+  /** Returns the active {@link Resource} for which Telemetry is reported. */
+  Resource getResource();
+}