public void testReferenceSize() {
if (!isSupportedJVM()) {
System.err.println("WARN: Your JVM does not support certain Oracle/Sun extensions.");
System.err.println(" Memory estimates may be inaccurate.");
System.err.println(" Please report this to the Lucene mailing list.");
System.err.println("JVM version: " + RamUsageEstimator.JVM_INFO_STRING);
System.err.println("UnsupportedFeatures:");
for (JvmFeature f : RamUsageEstimator.getUnsupportedFeatures()) {
System.err.print(" - " + f.toString());
if (f == RamUsageEstimator.JvmFeature.OBJECT_ALIGNMENT) {
System.err.print(
"; Please note: 32bit Oracle/Sun VMs don't allow exact OBJECT_ALIGNMENT retrieval, this is a known issue.");
}
System.err.println();
}
}
assertTrue(NUM_BYTES_OBJECT_REF == 4 || NUM_BYTES_OBJECT_REF == 8);
if (!Constants.JRE_IS_64BIT) {
assertEquals("For 32bit JVMs, reference size must always be 4?", 4, NUM_BYTES_OBJECT_REF);
}
}
/**
* Returns true, if the current JVM is fully supported by {@code RamUsageEstimator}. If this
* method returns {@code false} you are maybe using a 3rd party Java VM that is not supporting
* Oracle/Sun private APIs. The memory estimates can be imprecise then (no way of detecting
* compressed references, alignments, etc.). Lucene still tries to use sensible defaults.
*/
public static boolean isSupportedJVM() {
return supportedFeatures.size() == JvmFeature.values().length;
}
