Move AgentClassLoader out of public API. (#1182)

* Move AgentClassLoader out of public API.

* Move tests too

* Keep auto-api on bootstrap classpath.

Author: Anuraag Agrawal

javaagent-bootstrap/javaagent-bootstrap.gradle

@@ -12,8 +12,8 @@ dependencies {
   implementation group: 'org.slf4j', name: 'slf4j-simple', version: versions.slf4j
   // ^ Generally a bad idea for libraries, but we're shadowing.
 
-  implementation project(':instrumentation-api')
   implementation project(':auto-api')
+  implementation project(':instrumentation-api')
 
   testImplementation project(':testing-common')
   testImplementation group: 'org.mockito', name: 'mockito-core', version: '2.19.0'

…mentation/auto/api/AgentClassLoader.java …avaagent/bootstrap/AgentClassLoader.javaauto-api/src/main/java/io/opentelemetry/instrumentation/auto/api/AgentClassLoader.java renamed to javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/AgentClassLoader.java auto-api/src/main/java/io/opentelemetry/instrumentation/auto/api/AgentClassLoader.java renamed to javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/AgentClassLoader.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package io.opentelemetry.instrumentation.auto.api;
+package io.opentelemetry.javaagent.bootstrap;
 
 import java.io.File;
 import java.net.MalformedURLException;
@@ -29,7 +29,6 @@
  * <p>It is built around the concept of a jar inside another jar. This classloader loads the files
  * of the internal jar to load classes and resources.
  */
-// TODO remove this from api
 public class AgentClassLoader extends URLClassLoader {
   static {
     ClassLoader.registerAsParallelCapable();

javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/AgentInitializer.java

@@ -214,7 +214,7 @@ private static ClassLoader createAgentClassLoader(String innerJarFilename, URL b
 
     Class<?> loaderClass =
         ClassLoader.getSystemClassLoader()
-            .loadClass("io.opentelemetry.instrumentation.auto.api.AgentClassLoader");
+            .loadClass("io.opentelemetry.javaagent.bootstrap.AgentClassLoader");
     Constructor constructor =
         loaderClass.getDeclaredConstructor(URL.class, String.class, ClassLoader.class);
     return (ClassLoader) constructor.newInstance(bootstrapURL, innerJarFilename, agentParent);

…tion/auto/api/InternalJarURLHandler.java …ent/bootstrap/InternalJarURLHandler.javaauto-api/src/main/java/io/opentelemetry/instrumentation/auto/api/InternalJarURLHandler.java renamed to javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/InternalJarURLHandler.java auto-api/src/main/java/io/opentelemetry/instrumentation/auto/api/InternalJarURLHandler.java renamed to javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/InternalJarURLHandler.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package io.opentelemetry.instrumentation.auto.api;
+package io.opentelemetry.javaagent.bootstrap;
 
 import java.io.ByteArrayInputStream;
 import java.io.File;
@@ -31,18 +31,17 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-// TODO remove this from api
 public class InternalJarURLHandler extends URLStreamHandler {
 
   private static final Logger log = LoggerFactory.getLogger(InternalJarURLHandler.class);
 
-  private static final WeakReference<Pair<String, JarEntry>> NULL = new WeakReference<>(null);
+  private static final WeakReference<ResolvedJarEntry> NULL = new WeakReference<>(null);
 
   private final String name;
   private final FileNotInInternalJar notFound;
   private final JarFile bootstrapJarFile;
 
-  private WeakReference<Pair<String, JarEntry>> cache = NULL;
+  private WeakReference<ResolvedJarEntry> cache = NULL;
 
   public InternalJarURLHandler(String internalJarFileName, URL bootstrapJarLocation) {
     name = internalJarFileName;
@@ -71,11 +70,11 @@ protected URLConnection openConnection(URL url) throws IOException {
     }
     // believe it or not, we're going to get called twice for this,
     // and the key will be a new object each time.
-    Pair<String, JarEntry> pair = cache.get();
-    if (null == pair || !filename.equals(pair.getLeft())) {
+    ResolvedJarEntry pair = cache.get();
+    if (null == pair || !filename.equals(pair.filename)) {
       JarEntry entry = bootstrapJarFile.getJarEntry(getResourcePath(filename));
       if (null != entry) {
-        pair = Pair.of(filename, entry);
+        pair = new ResolvedJarEntry(filename, entry);
         // the cache field is not volatile as a performance optimization
         // in the rare event this write is not visible to another thread,
         // it just means the same work is recomputed but does not affect consistency
@@ -88,7 +87,7 @@ protected URLConnection openConnection(URL url) throws IOException {
       // so dismiss cache after a hit
       cache = NULL;
     }
-    return new InternalJarURLConnection(url, bootstrapJarFile.getInputStream(pair.getRight()));
+    return new InternalJarURLConnection(url, bootstrapJarFile.getInputStream(pair.entry));
   }
 
   private String getResourcePath(String filename) {
@@ -141,4 +140,14 @@ public Throwable fillInStackTrace() {
       return this;
     }
   }
+
+  private static class ResolvedJarEntry {
+    private final String filename;
+    private final JarEntry entry;
+
+    private ResolvedJarEntry(String filename, JarEntry entry) {
+      this.filename = filename;
+      this.entry = entry;
+    }
+  }
 }

…ion/auto/api/AgentClassLoaderTest.groovy …nt/bootstrap/AgentClassLoaderTest.groovyauto-api/src/test/groovy/io/opentelemetry/instrumentation/auto/api/AgentClassLoaderTest.groovy renamed to javaagent-bootstrap/src/test/java/io/opentelemetry/javaagent/bootstrap/AgentClassLoaderTest.groovy auto-api/src/test/groovy/io/opentelemetry/instrumentation/auto/api/AgentClassLoaderTest.groovy renamed to javaagent-bootstrap/src/test/java/io/opentelemetry/javaagent/bootstrap/AgentClassLoaderTest.groovy

@@ -14,8 +14,9 @@
  * limitations under the License.
  */
 
-package io.opentelemetry.instrumentation.auto.api
+package io.opentelemetry.javaagent.bootstrap
 
+import io.opentelemetry.javaagent.bootstrap.AgentClassLoader
 import java.util.concurrent.Phaser
 import java.util.concurrent.TimeUnit
 import spock.lang.Specification

…uto/api/InternalJarURLHandlerTest.groovy …otstrap/InternalJarURLHandlerTest.groovyauto-api/src/test/groovy/io/opentelemetry/instrumentation/auto/api/InternalJarURLHandlerTest.groovy renamed to javaagent-bootstrap/src/test/java/io/opentelemetry/javaagent/bootstrap/InternalJarURLHandlerTest.groovy auto-api/src/test/groovy/io/opentelemetry/instrumentation/auto/api/InternalJarURLHandlerTest.groovy renamed to javaagent-bootstrap/src/test/java/io/opentelemetry/javaagent/bootstrap/InternalJarURLHandlerTest.groovy

@@ -14,9 +14,10 @@
  * limitations under the License.
  */
 
-package io.opentelemetry.instrumentation.auto.api
+package io.opentelemetry.javaagent.bootstrap
 
 import io.opentelemetry.auto.util.test.AgentSpecification
+import io.opentelemetry.javaagent.bootstrap.InternalJarURLHandler
 import spock.lang.Shared
 
 class InternalJarURLHandlerTest extends AgentSpecification {

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/ClassLoaderMatcher.java

@@ -54,7 +54,7 @@ private static class SkipClassLoaderMatcher
     public static final SkipClassLoaderMatcher INSTANCE = new SkipClassLoaderMatcher();
     /* Cache of classloader-instance -> (true|false). True = skip instrumentation. False = safe to instrument. */
     private static final String AGENT_CLASSLOADER_NAME =
-        "io.opentelemetry.instrumentation.auto.api.AgentClassLoader";
+        "io.opentelemetry.javaagent.bootstrap.AgentClassLoader";
     private static final String EXPORTER_CLASSLOADER_NAME =
         "io.opentelemetry.javaagent.tooling.ExporterClassLoader";
     private static final WeakCache<ClassLoader, Boolean> skipCache = AgentTooling.newWeakCache();

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/Utils.java

@@ -18,8 +18,8 @@
 
 import static net.bytebuddy.matcher.ElementMatchers.named;
 
-import io.opentelemetry.instrumentation.auto.api.AgentClassLoader;
-import io.opentelemetry.instrumentation.auto.api.AgentClassLoader.BootstrapClassLoaderProxy;
+import io.opentelemetry.javaagent.bootstrap.AgentClassLoader;
+import io.opentelemetry.javaagent.bootstrap.AgentClassLoader.BootstrapClassLoaderProxy;
 import java.lang.reflect.Method;
 import java.net.URL;
 import net.bytebuddy.description.method.MethodDescription;

javaagent-tooling/src/test/groovy/io/opentelemetry/javaagent/test/ClassLoaderMatcherTest.groovy

@@ -17,7 +17,7 @@
 package io.opentelemetry.auto.test
 
 import io.opentelemetry.auto.util.test.AgentSpecification
-import io.opentelemetry.instrumentation.auto.api.AgentClassLoader
+import io.opentelemetry.javaagent.bootstrap.AgentClassLoader
 import io.opentelemetry.javaagent.tooling.ClassLoaderMatcher
 import io.opentelemetry.javaagent.tooling.ExporterClassLoader
 import io.opentelemetry.javaagent.tooling.log.LogContextScopeListener
@@ -54,7 +54,7 @@ class ClassLoaderMatcherTest extends AgentSpecification {
 
   def "AgentClassLoader class name is hardcoded in ClassLoaderMatcher"() {
     expect:
-    AgentClassLoader.name == "io.opentelemetry.instrumentation.auto.api.AgentClassLoader"
+    AgentClassLoader.name == "io.opentelemetry.javaagent.bootstrap.AgentClassLoader"
   }
 
   def "ExporterClassLoader class name is hardcoded in ClassLoaderMatcher"() {