Split API packages, move context in the same directory (#2199)

There are some things left to be done:
* Decide if context package should also be opentelemetry-api-context.
* Cleanup internal packages, things that are used by only one artifact should be moved there.

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

api/all/README.md

@@ -2,7 +2,7 @@
 
 [![Javadocs][javadoc-image]][javadoc-url]
 
-* The abstract classes in this directory can be subclassed to create alternative
+* The interfaces in this directory can be implemented to create alternative
   implementations of the OpenTelemetry library.
 
 [javadoc-image]: https://www.javadoc.io/badge/io.opentelemetry/opentelemetry-api.svg

api/all/build.gradle

@@ -0,0 +1,26 @@
+plugins {
+    id "java"
+    id "maven-publish"
+
+    id "me.champeau.gradle.jmh"
+    id "ru.vyarus.animalsniffer"
+}
+
+description = 'OpenTelemetry API'
+ext.moduleName = "io.opentelemetry.api"
+
+dependencies {
+    api project(':opentelemetry-context'),
+            project(':opentelemetry-api-baggage'),
+            project(':opentelemetry-api-common'),
+            project(':opentelemetry-api-internal'),
+            project(':opentelemetry-api-metrics'),
+            project(':opentelemetry-api-trace')
+
+    annotationProcessor libraries.auto_value
+
+    signature libraries.android_signature
+
+    testImplementation libraries.jqf,
+            libraries.guava_testlib
+}

api/all/src/test/java/io/opentelemetry/api/OpenTelemetryTest.java

@@ -242,7 +242,7 @@ class OpenTelemetryTest {
   }
 
   private static File createService(Class<?> service, Class<?>... impls) throws IOException {
-    URL location = Tracer.class.getProtectionDomain().getCodeSource().getLocation();
+    URL location = OpenTelemetryTest.class.getProtectionDomain().getCodeSource().getLocation();
     File file = new File(location.getPath() + "META-INF/services/" + service.getName());
     file.getParentFile().mkdirs();
 

api/baggage/README.md

@@ -0,0 +1,6 @@
+# OpenTelemetry Baggage API
+
+[![Javadocs][javadoc-image]][javadoc-url]
+
+[javadoc-image]: https://www.javadoc.io/badge/io.opentelemetry/opentelemetry-api-baggage.svg
+[javadoc-url]: https://www.javadoc.io/doc/io.opentelemetry/opentelemetry-api-baggage

api/baggage/build.gradle

@@ -0,0 +1,22 @@
+plugins {
+    id "java"
+    id "maven-publish"
+
+    id "me.champeau.gradle.jmh"
+    id "ru.vyarus.animalsniffer"
+}
+
+description = 'OpenTelemetry API'
+ext.moduleName = "io.opentelemetry.api"
+
+dependencies {
+    api project(':opentelemetry-context'),
+            project(':opentelemetry-api-internal')
+
+    annotationProcessor libraries.auto_value
+
+    signature libraries.android_signature
+
+    testImplementation libraries.jqf,
+            libraries.guava_testlib
+}

api/common/README.md

@@ -0,0 +1,6 @@
+# OpenTelemetry Common API
+
+[![Javadocs][javadoc-image]][javadoc-url]
+
+[javadoc-image]: https://www.javadoc.io/badge/io.opentelemetry/opentelemetry-api-common.svg
+[javadoc-url]: https://www.javadoc.io/doc/io.opentelemetry/opentelemetry-api-common

api/common/build.gradle

@@ -0,0 +1,21 @@
+plugins {
+    id "java"
+    id "maven-publish"
+
+    id "me.champeau.gradle.jmh"
+    id "ru.vyarus.animalsniffer"
+}
+
+description = 'OpenTelemetry API'
+ext.moduleName = "io.opentelemetry.api.common"
+
+dependencies {
+    api project(':opentelemetry-api-internal')
+
+    annotationProcessor libraries.auto_value
+
+    signature libraries.android_signature
+
+    testImplementation libraries.jqf,
+            libraries.guava_testlib
+}

api/internal/README.md

@@ -0,0 +1,6 @@
+# OpenTelemetry Internal API
+
+[![Javadocs][javadoc-image]][javadoc-url]
+
+[javadoc-image]: https://www.javadoc.io/badge/io.opentelemetry/opentelemetry-api-internal.svg
+[javadoc-url]: https://www.javadoc.io/doc/io.opentelemetry/opentelemetry-api-internal

api/internal/build.gradle

@@ -7,7 +7,7 @@ plugins {
 }
 
 description = 'OpenTelemetry API'
-ext.moduleName = "io.opentelemetry.api"
+ext.moduleName = "io.opentelemetry.api.internal"
 
 dependencies {
     api project(':opentelemetry-context')

api/internal/src/main/java/io/opentelemetry/api/internal/ImmutableKeyValuePairs.java

@@ -7,8 +7,6 @@ package io.opentelemetry.api.internal;
 
 import static io.opentelemetry.api.internal.Utils.checkArgument;
 
-import io.opentelemetry.api.common.Attributes;
-import io.opentelemetry.api.common.Labels;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -26,8 +24,6 @@ import javax.annotation.concurrent.Immutable;
  * boolean)}, assuming you don't want the "empty" keys to be kept in your collection.
  *
  * @param <V> The type of the values contained in this.
- * @see Labels
- * @see Attributes
  */
 @SuppressWarnings("rawtypes")
 @Immutable