Fixes #2720: Use StackWalker on Java 9+ to create Locations (#2723)

In terms of memory allocations, this reduces the overall memory
allocations of creating a location by an order of magnitude in
Java 9, and as compared to Java 8.

The implementation is somewhat involved due to these desires:

- Minimize the amount of work done if the Location is never used. This
  is done by not converting the StackFrame into a StackTraceElement,
  instead wrapping in an intermediate state. The StackTraceElement conversion
  will only occur (internally) if the .getFileName() method is called.
- Ensure the implementation is still Serializable. This is ensured with
  a .writeReplace method.
- Minimize the number of allocations, which is basically an exercise in
  lambda caching.
- Ensuring the old mechanism still works on Java 8.

Presently on Java 9+, on a stack depth of 1000 the old mechanism will allocate
40kB of RAM per call. The new one will allocate 1.5kB of RAM per call,
which is a huge improvement.

This is still sadly not the 'close-to-no-overhead' solution I was
looking for. I therefore also added a system property that can be used
to fully disable Location creation. I'm aware that this is likely not
the right approach given Mockito has plugins and settings - mostly
looking for guidance here given I'm not sure what would be idiomatic
here.

src/main/java/org/mockito/exceptions/stacktrace/StackTraceCleaner.java

@@ -25,4 +25,29 @@ public interface StackTraceCleaner {
      * @return whether the element should be excluded from cleaned stack trace.
      */
     boolean isIn(StackTraceElement candidate);
+
+    /**
+     * It's recommended to override this method in subclasses to avoid potentially costly re-boxing operations.
+     */
+    default boolean isIn(StackFrameMetadata candidate) {
+        return isIn(
+                new StackTraceElement(
+                        candidate.getClassName(),
+                        candidate.getMethodName(),
+                        candidate.getFileName(),
+                        candidate.getLineNumber()));
+    }
+
+    /**
+     * Very similar to the StackFrame class declared on the StackWalker api.
+     */
+    interface StackFrameMetadata {
+        String getClassName();
+
+        String getMethodName();
+
+        String getFileName();
+
+        int getLineNumber();
+    }
 }

src/main/java/org/mockito/internal/MockedConstructionImpl.java

@@ -11,7 +11,7 @@
 
 import org.mockito.MockedConstruction;
 import org.mockito.exceptions.base.MockitoException;
-import org.mockito.internal.debugging.LocationImpl;
+import org.mockito.internal.debugging.LocationFactory;
 import org.mockito.invocation.Location;
 import org.mockito.plugins.MockMaker;
 
@@ -21,7 +21,7 @@ public final class MockedConstructionImpl<T> implements MockedConstruction<T> {
 
     private boolean closed;
 
-    private final Location location = new LocationImpl();
+    private final Location location = LocationFactory.create();
 
     protected MockedConstructionImpl(MockMaker.ConstructionMockControl<T> control) {
         this.control = control;

src/main/java/org/mockito/internal/MockedStaticImpl.java

@@ -17,7 +17,7 @@
 import org.mockito.Mockito;
 import org.mockito.exceptions.base.MockitoAssertionError;
 import org.mockito.exceptions.base.MockitoException;
-import org.mockito.internal.debugging.LocationImpl;
+import org.mockito.internal.debugging.LocationFactory;
 import org.mockito.internal.listeners.VerificationStartedNotifier;
 import org.mockito.internal.progress.MockingProgress;
 import org.mockito.internal.stubbing.InvocationContainerImpl;
@@ -35,7 +35,7 @@ public final class MockedStaticImpl<T> implements MockedStatic<T> {
 
     private boolean closed;
 
-    private final Location location = new LocationImpl();
+    private final Location location = LocationFactory.create();
 
     protected MockedStaticImpl(MockMaker.StaticMockControl<T> control) {
         this.control = control;

src/main/java/org/mockito/internal/creation/bytebuddy/MockMethodAdvice.java

@@ -51,7 +51,7 @@
 import org.mockito.exceptions.base.MockitoException;
 import org.mockito.internal.configuration.plugins.Plugins;
 import org.mockito.internal.creation.bytebuddy.inject.MockMethodDispatcher;
-import org.mockito.internal.debugging.LocationImpl;
+import org.mockito.internal.debugging.LocationFactory;
 import org.mockito.internal.exceptions.stacktrace.ConditionalStackTraceFilter;
 import org.mockito.internal.invocation.RealMethod;
 import org.mockito.internal.invocation.SerializableMethod;
@@ -132,11 +132,7 @@ public Callable<?> handle(Object instance, Method origin, Object[] arguments) th
         }
         return new ReturnValueWrapper(
                 interceptor.doIntercept(
-                        instance,
-                        origin,
-                        arguments,
-                        realMethod,
-                        new LocationImpl(new Throwable(), true)));
+                        instance, origin, arguments, realMethod, LocationFactory.create(true)));
     }
 
     @Override
@@ -154,7 +150,7 @@ public Callable<?> handleStatic(Class<?> type, Method origin, Object[] arguments
                                 origin,
                                 arguments,
                                 new StaticMethodCall(selfCallInfo, type, origin, arguments),
-                                new LocationImpl(new Throwable(), true)));
+                                LocationFactory.create(true)));
     }
 
     @Override

src/main/java/org/mockito/internal/creation/bytebuddy/MockMethodInterceptor.java

@@ -22,7 +22,7 @@
 import net.bytebuddy.implementation.bind.annotation.StubValue;
 import net.bytebuddy.implementation.bind.annotation.SuperCall;
 import net.bytebuddy.implementation.bind.annotation.This;
-import org.mockito.internal.debugging.LocationImpl;
+import org.mockito.internal.debugging.LocationFactory;
 import org.mockito.internal.invocation.RealMethod;
 import org.mockito.invocation.Location;
 import org.mockito.invocation.MockHandler;
@@ -53,7 +53,7 @@ private void readObject(ObjectInputStream stream) throws IOException, ClassNotFo
 
     Object doIntercept(Object mock, Method invokedMethod, Object[] arguments, RealMethod realMethod)
             throws Throwable {
-        return doIntercept(mock, invokedMethod, arguments, realMethod, new LocationImpl());
+        return doIntercept(mock, invokedMethod, arguments, realMethod, LocationFactory.create());
     }
 
     Object doIntercept(

src/main/java/org/mockito/internal/creation/proxy/ProxyMockMaker.java

@@ -5,7 +5,7 @@
 package org.mockito.internal.creation.proxy;
 
 import org.mockito.exceptions.base.MockitoException;
-import org.mockito.internal.debugging.LocationImpl;
+import org.mockito.internal.debugging.LocationFactory;
 import org.mockito.internal.invocation.RealMethod;
 import org.mockito.internal.util.Platform;
 import org.mockito.invocation.MockHandler;
@@ -153,7 +153,12 @@ public Object invoke(Object proxy, Method method, Object[] args) throws Throwabl
             return handler.get()
                     .handle(
                             createInvocation(
-                                    proxy, method, args, realMethod, settings, new LocationImpl()));
+                                    proxy,
+                                    method,
+                                    args,
+                                    realMethod,
+                                    settings,
+                                    LocationFactory.create()));
         }
     }
 

src/main/java/org/mockito/internal/debugging/LocationImpl.java → src/main/java/org/mockito/internal/debugging/Java8LocationImpl.java

@@ -9,7 +9,7 @@
 import org.mockito.internal.exceptions.stacktrace.StackTraceFilter;
 import org.mockito.invocation.Location;
 
-public class LocationImpl implements Location, Serializable {
+class Java8LocationImpl implements Location, Serializable {
 
     private static final long serialVersionUID = -9054861157390980624L;
     // Limit the amount of objects being created, as this class is heavily instantiated:
@@ -18,19 +18,11 @@ public class LocationImpl implements Location, Serializable {
     private String stackTraceLine;
     private String sourceFile;
 
-    public LocationImpl() {
-        this(new Throwable(), false);
-    }
-
-    public LocationImpl(Throwable stackTraceHolder, boolean isInline) {
+    public Java8LocationImpl(Throwable stackTraceHolder, boolean isInline) {
         this(stackTraceFilter, stackTraceHolder, isInline);
     }
 
-    public LocationImpl(StackTraceFilter stackTraceFilter) {
-        this(stackTraceFilter, new Throwable(), false);
-    }
-
-    private LocationImpl(
+    private Java8LocationImpl(
             StackTraceFilter stackTraceFilter, Throwable stackTraceHolder, boolean isInline) {
         computeStackTraceInformation(stackTraceFilter, stackTraceHolder, isInline);
     }