Merge pull request #2978 from ebean-orm/feature/stackWalker

Use StackWalker for ProfileLocation and CallOrigin

ebean-api/src/main/java/io/ebean/bean/CallStack.java

@@ -2,6 +2,7 @@ package io.ebean.bean;
 
 import java.io.Serializable;
 import java.util.Arrays;
+import java.util.List;
 
 import static io.ebean.util.EncodeB64.enc;
 
@@ -27,19 +28,26 @@ public final class CallStack implements Serializable, CallOrigin {
 
   private final String zeroHash;
   private final String pathHash;
-  private final StackTraceElement[] callStack;
+  private final Object[] callStack;
   private final int hc;
 
-  public CallStack(StackTraceElement[] callStack, int zeroHash, int pathHash) {
+  public CallStack(Object[] callStack, int zeroHash, int pathHash) {
     this.callStack = callStack;
+    this.hc = computeHashCode();
     this.zeroHash = enc(zeroHash);
     this.pathHash = enc(pathHash);
+  }
+
+  public CallStack(List<StackWalker.StackFrame> frames) {
+    this.callStack = frames.toArray(new Object[0]);
     this.hc = computeHashCode();
+    this.zeroHash = enc(callStack[0].hashCode());
+    this.pathHash = enc(hc);
   }
 
   private int computeHashCode() {
     int hc = 0;
-    for (StackTraceElement element : callStack) {
+    for (Object element : callStack) {
       hc = 92821 * hc + element.hashCode();
     }
     return hc;

ebean-api/src/main/java/io/ebean/util/StackWalkFilter.java

@@ -0,0 +1,28 @@
+package io.ebean.util;
+
+import java.util.function.Predicate;
+
+/**
+ * Provides a stack filter that excludes ebean and jdk code.
+ */
+public final class StackWalkFilter {
+
+  private static final Filter FILTER = new Filter();
+
+  /**
+   * Return a stack filter that excludes ebean and jdk code.
+   */
+  public static Predicate<StackWalker.StackFrame> filter() {
+    return FILTER;
+  }
+
+  private static class Filter implements Predicate<StackWalker.StackFrame> {
+
+    @Override
+    public boolean test(StackWalker.StackFrame stackFrame) {
+      return !stackFrame.getClassName().startsWith("io.ebean")
+        && !stackFrame.getClassName().startsWith("jdk.")
+        && !stackFrame.getMethodName().startsWith("_ebean_");
+    }
+  }
+}

ebean-core/src/main/java/io/ebeaninternal/server/core/DefaultCallOriginFactory.java

@@ -2,17 +2,17 @@ package io.ebeaninternal.server.core;
 
 import io.ebean.bean.CallOrigin;
 import io.ebean.bean.CallStack;
+import io.ebean.util.StackWalkFilter;
 
 import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 /**
  * Default CallStackFactory where the Hash function for StackTraceElement includes the line number.
  */
-public final class DefaultCallOriginFactory implements CallOriginFactory {
-
-  private static final int IGNORE_LEADING_ELEMENTS = 5;
-
-  private static final String IO_EBEAN = "io.ebean";
+final class DefaultCallOriginFactory implements CallOriginFactory {
 
   private final int maxCallStack;
 
@@ -22,57 +22,18 @@ public final class DefaultCallOriginFactory implements CallOriginFactory {
 
   @Override
   public CallOrigin createCallOrigin() {
-     StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
-
-    // ignore the first 6 as they are always avaje stack elements
-    int startIndex = IGNORE_LEADING_ELEMENTS;
-
-    // find the first non-avaje stackElement
-    for (; startIndex < stackTrace.length; startIndex++) {
-      if (!ignore(stackTrace[startIndex])) {
-        break;
-      }
-    }
-
-    int stackLength = stackTrace.length - startIndex;
-    if (stackLength > maxCallStack) {
-      // maximum of maxCallStack stackTrace elements
-      stackLength = maxCallStack;
-    }
-
-    // create the 'interesting' part of the stackTrace
-    StackTraceElement[] finalTrace = new StackTraceElement[stackLength];
-    System.arraycopy(stackTrace, startIndex, finalTrace, 0, stackLength);
-
-    if (stackLength < 1) {
+    final var frames = StackWalker.getInstance().walk(this::filter);
+    if (frames.isEmpty()) {
       // this should not really happen
-      throw new RuntimeException("StackTraceElement size 0?  stack: " + Arrays.toString(stackTrace));
+      throw new RuntimeException("stackFrames filtered to empty for stack: " + Arrays.toString(Thread.currentThread().getStackTrace()));
     }
-
-    return createCallStack(finalTrace);
+    return new CallStack(frames);
   }
 
-  private boolean ignore(StackTraceElement element) {
-    if (element.getClassName().startsWith(IO_EBEAN)) {
-      return true;
-    }
-    return element.getMethodName().startsWith("_ebean_");
-  }
-
-  private CallOrigin createCallStack(StackTraceElement[] finalTrace) {
-    return new CallStack(finalTrace, finalTrace[0].hashCode(), pathHash(finalTrace));
-  }
-
-  /**
-   * Return the hash code for the path excluding the first element.
-   */
-  private int pathHash(StackTraceElement[] callStack) {
-
-    int hc = 0;
-    for (int i = 1; i < callStack.length; i++) {
-      hc = 92821 * hc + callStack[i].hashCode();
-    }
-    return hc;
+  private <T> List<StackWalker.StackFrame> filter(Stream<StackWalker.StackFrame> frames) {
+    return frames.filter(StackWalkFilter.filter())
+      .limit(maxCallStack)
+      .collect(Collectors.toList());
   }
 
 }

ebean-core/src/main/java/io/ebeaninternal/server/core/NoopCallOriginFactory.java

@@ -10,7 +10,7 @@ final class NoopCallOriginFactory implements CallOriginFactory {
 
   private static final StackTraceElement E0 = new StackTraceElement("none", "none", "none", 0);
 
-  private final CallOrigin COMMON = new CallStack(new StackTraceElement[]{E0}, 0, 0);
+  private final CallOrigin COMMON = new CallStack(new Object[]{E0}, 0, 0);
 
   @Override
   public CallOrigin createCallOrigin() {

ebean-core/src/main/java/io/ebeaninternal/server/profile/DProfileLocation.java

@@ -1,13 +1,15 @@
 package io.ebeaninternal.server.profile;
 
 import io.ebean.ProfileLocation;
+import io.ebean.util.StackWalkFilter;
+
+import java.util.stream.Stream;
 
 /**
  * Default profile location that uses stack trace.
  */
 class DProfileLocation implements ProfileLocation {
 
-  private static final String IO_EBEAN = "io.ebean";
   private static final String UNKNOWN = "unknown";
 
   private String fullLocation;
@@ -88,14 +90,14 @@ class DProfileLocation implements ProfileLocation {
   }
 
   private String create() {
-    // relatively expensive but we only do it once per profile location
-    StackTraceElement[] trace = Thread.currentThread().getStackTrace();
-    for (int i = 3; i < trace.length; i++) {
-      if (!trace[i].getClassName().startsWith(IO_EBEAN)) {
-        return withLineNumber(trace[i].toString());
-      }
-    }
-    return UNKNOWN;
+    return StackWalker.getInstance().walk(this::filter);
+  }
+
+  private String filter(Stream<StackWalker.StackFrame> frames) {
+    return frames.filter(StackWalkFilter.filter())
+      .findFirst()
+      .map(line -> withLineNumber(line.toString()))
+      .orElse(UNKNOWN);
   }
 
   private String withLineNumber(String traceLine) {

ebean-core/src/test/java/io/ebeaninternal/server/core/HelpDefaultCallOriginFactory.java

@@ -0,0 +1,11 @@
+package io.ebeaninternal.server.core;
+
+/**
+ * Make DefaultCallOriginFactory accessible to tests.
+ */
+public class HelpDefaultCallOriginFactory {
+
+  public static CallOriginFactory create(int maxStack) {
+    return new DefaultCallOriginFactory(maxStack);
+  }
+}

ebean-core/src/test/java/io/ebeaninternal/server/profile/BasicProfileLocationTest.java

@@ -54,21 +54,10 @@ class BasicProfileLocationTest {
   void obtain() {
     DProfileLocation loc = new DTimedProfileLocation(12, "foo", MetricFactory.get().createTimedMetric("junk"));
 
-    String javaVersion = System.getProperty("java.version");
     assertThat(loc.obtain()).isTrue();
-    if (javaVersion.startsWith("1.8")) {
-      assertThat(loc.fullLocation()).endsWith("invoke0(Native Method:12)");
-      assertThat(loc.location()).isEqualTo("sun.reflect.NativeMethodAccessorImpl.invoke0");
-      assertThat(loc.label()).isEqualTo("NativeMethodAccessorImpl.invoke0");
-    } else if (javaVersion.startsWith("18") || javaVersion.startsWith("19") || javaVersion.startsWith("20")){
-      assertThat(loc.fullLocation()).endsWith("jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)");
-      assertThat(loc.location()).isEqualTo("java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke");
-      assertThat(loc.label()).isEqualTo("DirectMethodHandleAccessor.invoke");
-    } else if (javaVersion.startsWith("11") || javaVersion.startsWith("17")) {
-      assertThat(loc.fullLocation()).endsWith("jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method:12)");
-      assertThat(loc.location()).isEqualTo("java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0");
-      assertThat(loc.label()).isEqualTo("NativeMethodAccessorImpl.invoke0");
-    }
+    assertThat(loc.fullLocation()).endsWith("org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:725)");
+    assertThat(loc.location()).isEqualTo("org.junit.platform.commons.util.ReflectionUtils.invokeMethod");
+    assertThat(loc.label()).isEqualTo("ReflectionUtils.invokeMethod");
   }
 
   @Test

ebean-core/src/test/java/org/tests/server/TestDefaultCallOriginFactory.java

@@ -0,0 +1,25 @@
+package org.tests.server;
+
+import io.ebean.bean.CallOrigin;
+import io.ebeaninternal.server.core.CallOriginFactory;
+import io.ebeaninternal.server.core.HelpDefaultCallOriginFactory;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class TestDefaultCallOriginFactory {
+
+  private final CallOriginFactory factory = HelpDefaultCallOriginFactory.create(2);
+
+  @Test
+  void createCallOrigin() {
+    CallOrigin callOrigin = inner();
+    String topElement = callOrigin.getTopElement();
+    assertThat(topElement).contains("org.tests.server.TestDefaultCallOriginFactory.inner(TestDefaultCallOriginFactory.java:23)");
+    assertThat(callOrigin.getFullDescription()).contains("TestDefaultCallOriginFactory.java:16");
+  }
+
+  private CallOrigin inner() {
+    return factory.createCallOrigin();
+  }
+}

ebean-test/src/test/java/org/tests/profile/ProfileLocationTest.java

@@ -5,7 +5,7 @@ import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-public class ProfileLocationTest {
+class ProfileLocationTest {
 
   private static final ProfileLocation loc = ProfileLocation.create(12, "foo");
   private static final ProfileLocation locB = ProfileLocation.create();
@@ -17,7 +17,7 @@ public class ProfileLocationTest {
   }
 
   @Test
-  public void test_obtain() {
+  void test_obtain() {
     assertThat(doIt()).isTrue();
     assertThat(loc.fullLocation()).isEqualTo("org.tests.profile.ProfileLocationTest.doIt(ProfileLocationTest.java:16)");
     assertThat(loc.location()).isEqualTo("org.tests.profile.ProfileLocationTest.doIt");
@@ -30,13 +30,12 @@ public class ProfileLocationTest {
   }
 
   @Test
-  public void test_add() {
+  void test_add() {
     loc.add(100);
   }
 
   @Test
-  public void test_constructor() {
-
+  void test_constructor() {
     Other other = new Other();
     other.hashCode();