Updating RamUsageEstimator with changes related to LUCENE-5086: RamUs…

…ageEstimator causes AWT classes to be loaded by calling ManagementFactory#getPlatformMBeanServer
dweiss · Jul 5, 2013 · bfd0570 · bfd0570
1 parent 1cd8176
commit bfd0570
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Showing 4 changed files with 103 additions and 25 deletions.
diff --git a/.classpath b/.classpath
@@ -1,8 +1,26 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
-	<classpathentry kind="src" output="target/classes" path="src/main/java"/>
-	<classpathentry kind="src" output="target/test-classes" path="src/test/java"/>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.6"/>
-	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER"/>
+	<classpathentry kind="src" output="target/classes" path="src/main/java">
+		<attributes>
+			<attribute name="optional" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="src" output="target/test-classes" path="src/test/java">
+		<attributes>
+			<attribute name="optional" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.6">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
 	<classpathentry kind="output" path="target/classes"/>
 </classpath>
diff --git a/.settings/org.eclipse.jdt.apt.core.prefs b/.settings/org.eclipse.jdt.apt.core.prefs
@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.apt.aptEnabled=false
diff --git a/.settings/org.eclipse.jdt.core.prefs b/.settings/org.eclipse.jdt.core.prefs
@@ -1,10 +1,10 @@
-#Mon Mar 19 22:47:48 CET 2012
 eclipse.preferences.version=1
 org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.6
 org.eclipse.jdt.core.compiler.compliance=1.6
 org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
 org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
 org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
+org.eclipse.jdt.core.compiler.processAnnotations=disabled
 org.eclipse.jdt.core.compiler.source=1.6
 org.eclipse.jdt.core.formatter.align_type_members_on_columns=false
 org.eclipse.jdt.core.formatter.alignment_for_arguments_in_allocation_expression=16

diff --git a/src/main/java/com/carrotsearch/sizeof/RamUsageEstimator.java b/src/main/java/com/carrotsearch/sizeof/RamUsageEstimator.java
@@ -31,6 +31,8 @@
  * Estimates the size (memory representation) of Java objects.
  * 
  * @see #sizeOf(Object)
+ * @see #shallowSizeOf(Object)
+ * @see #shallowSizeOfInstance(Class)
  */
 public final class RamUsageEstimator {
   /**
@@ -69,14 +71,14 @@ public String toString() {
   /** No instantiation. */
   private RamUsageEstimator() {}
 
-  private final static int NUM_BYTES_BOOLEAN = 1;
-  private final static int NUM_BYTES_BYTE = 1;
-  private final static int NUM_BYTES_CHAR = 2;
-  private final static int NUM_BYTES_SHORT = 2;
-  private final static int NUM_BYTES_INT = 4;
-  private final static int NUM_BYTES_FLOAT = 4;
-  private final static int NUM_BYTES_LONG = 8;
-  private final static int NUM_BYTES_DOUBLE = 8;
+  public final static int NUM_BYTES_BOOLEAN = 1;
+  public final static int NUM_BYTES_BYTE = 1;
+  public final static int NUM_BYTES_CHAR = 2;
+  public final static int NUM_BYTES_SHORT = 2;
+  public final static int NUM_BYTES_INT = 4;
+  public final static int NUM_BYTES_FLOAT = 4;
+  public final static int NUM_BYTES_LONG = 8;
+  public final static int NUM_BYTES_DOUBLE = 8;
 
   /** 
    * Number of bytes this jvm uses to represent an object reference. 
@@ -177,7 +179,7 @@ private RamUsageEstimator() {}
     // estimateRamUsage().
     Method tempObjectFieldOffsetMethod = null;
     try {
-      Method objectFieldOffsetM = unsafeClass.getMethod("objectFieldOffset", Field.class);
+      final Method objectFieldOffsetM = unsafeClass.getMethod("objectFieldOffset", Field.class);
       final Field dummy1Field = DummyTwoLongObject.class.getDeclaredField("dummy1");
       final int ofs1 = ((Number) objectFieldOffsetM.invoke(theUnsafe, dummy1Field)).intValue();
       final Field dummy2Field = DummyTwoLongObject.class.getDeclaredField("dummy2");
@@ -213,17 +215,33 @@ private RamUsageEstimator() {}
     int objectAlignment = 8;
     try {
       final Class<?> beanClazz = Class.forName("com.sun.management.HotSpotDiagnosticMXBean");
-      final Object hotSpotBean = ManagementFactory.newPlatformMXBeanProxy(
-        ManagementFactory.getPlatformMBeanServer(),
-        "com.sun.management:type=HotSpotDiagnostic",
-        beanClazz
-      );
-      final Method getVMOptionMethod = beanClazz.getMethod("getVMOption", String.class);
-      final Object vmOption = getVMOptionMethod.invoke(hotSpotBean, "ObjectAlignmentInBytes");
-      objectAlignment = Integer.parseInt(
-          vmOption.getClass().getMethod("getValue").invoke(vmOption).toString()
-      );
-      supportedFeatures.add(JvmFeature.OBJECT_ALIGNMENT);        
+      // Try to get the diagnostic mxbean without calling {@link ManagementFactory#getPlatformMBeanServer()}
+      // which starts AWT thread (and shows junk in the dock) on a Mac:
+      Object hotSpotBean;
+      // Java 7+, HotSpot
+      try {
+        hotSpotBean = ManagementFactory.class
+          .getMethod("getPlatformMXBean", Class.class)
+          .invoke(null, beanClazz);
+      } catch (Exception e1) {
+        // Java 6, HotSpot
+        try {
+          Class<?> sunMF = Class.forName("sun.management.ManagementFactory");
+          hotSpotBean = sunMF.getMethod("getDiagnosticMXBean").invoke(null);
+        } catch (Exception e2) {
+          // Last resort option is an attempt to get it from ManagementFactory's server anyway (may start AWT).
+          hotSpotBean = ManagementFactory.newPlatformMXBeanProxy(
+              ManagementFactory.getPlatformMBeanServer(),
+              "com.sun.management:type=HotSpotDiagnostic", beanClazz);
+        }
+      }
+      if (hotSpotBean != null) {
+        final Method getVMOptionMethod = beanClazz.getMethod("getVMOption", String.class);
+        final Object vmOption = getVMOptionMethod.invoke(hotSpotBean, "ObjectAlignmentInBytes");
+        objectAlignment = Integer.parseInt(
+            vmOption.getClass().getMethod("getValue").invoke(vmOption).toString());
+        supportedFeatures.add(JvmFeature.OBJECT_ALIGNMENT);
+      }
     } catch (Exception e) {
       // Ignore.
     }
@@ -280,6 +298,46 @@ public static long alignObjectSize(long size) {
     return size - (size % NUM_BYTES_OBJECT_ALIGNMENT);
   }
 
+  /** Returns the size in bytes of the byte[] object. */
+  public static long sizeOf(byte[] arr) {
+    return alignObjectSize((long) NUM_BYTES_ARRAY_HEADER + arr.length);
+  }
+
+  /** Returns the size in bytes of the boolean[] object. */
+  public static long sizeOf(boolean[] arr) {
+    return alignObjectSize((long) NUM_BYTES_ARRAY_HEADER + arr.length);
+  }
+
+  /** Returns the size in bytes of the char[] object. */
+  public static long sizeOf(char[] arr) {
+    return alignObjectSize((long) NUM_BYTES_ARRAY_HEADER + (long) NUM_BYTES_CHAR * arr.length);
+  }
+
+  /** Returns the size in bytes of the short[] object. */
+  public static long sizeOf(short[] arr) {
+    return alignObjectSize((long) NUM_BYTES_ARRAY_HEADER + (long) NUM_BYTES_SHORT * arr.length);
+  }
+
+  /** Returns the size in bytes of the int[] object. */
+  public static long sizeOf(int[] arr) {
+    return alignObjectSize((long) NUM_BYTES_ARRAY_HEADER + (long) NUM_BYTES_INT * arr.length);
+  }
+
+  /** Returns the size in bytes of the float[] object. */
+  public static long sizeOf(float[] arr) {
+    return alignObjectSize((long) NUM_BYTES_ARRAY_HEADER + (long) NUM_BYTES_FLOAT * arr.length);
+  }
+
+  /** Returns the size in bytes of the long[] object. */
+  public static long sizeOf(long[] arr) {
+    return alignObjectSize((long) NUM_BYTES_ARRAY_HEADER + (long) NUM_BYTES_LONG * arr.length);
+  }
+
+  /** Returns the size in bytes of the double[] object. */
+  public static long sizeOf(double[] arr) {
+    return alignObjectSize((long) NUM_BYTES_ARRAY_HEADER + (long) NUM_BYTES_DOUBLE * arr.length);
+  }
+
   /** 
    * Estimates the RAM usage by the given object. It will
    * walk the object tree and sum up all referenced objects.