org.apache.hudi.org.openjdk.jol.info.GraphWalker Maven / Gradle / Ivy
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* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
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package org.openjdk.jol.info;
import org.openjdk.jol.util.ObjectUtils;
import org.openjdk.jol.util.SimpleIdentityHashSet;
import org.openjdk.jol.util.SimpleStack;
import org.openjdk.jol.vm.VM;
import java.lang.reflect.Field;
import java.util.HashMap;
/**
* Concrete class to walk object graphs.
*
* @author Aleksey Shipilev
*/
public class GraphWalker extends AbstractGraphWalker {
private final GraphVisitor[] visitors;
private final HashMap, Long> sizeCache;
public GraphWalker(GraphVisitor... visitor) {
this.visitors = visitor;
sizeCache = new HashMap<>();
}
public GraphLayout walk(Object... roots) {
verifyRoots(roots);
GraphLayout data = new GraphLayout(roots);
SimpleIdentityHashSet visited = new SimpleIdentityHashSet();
SimpleStack s = new SimpleStack<>();
int rootId = 1;
boolean single = (roots.length == 1);
for (Object root : roots) {
String label = single ? "" : ("");
GraphPathRecord e = new FieldGraphPathRecord(null, label, 0, root);
if (visited.add(root)) {
data.addRecord(e);
s.push(e);
}
rootId++;
}
while (!s.isEmpty()) {
GraphPathRecord cGpr = s.pop();
Object o = cGpr.obj();
Class cl = o.getClass();
if (cl.isArray()) {
if (cl.getComponentType().isPrimitive()) {
// Nothing to do here
continue;
}
Object[] arr = (Object[]) o;
for (int i = 0; i < arr.length; i++) {
Object e = arr[i];
if (e != null && visited.add(e)) {
GraphPathRecord gpr = new ArrayGraphPathRecord(cGpr, i, cGpr.depth() + 1, e);
data.addRecord(gpr);
for (GraphVisitor v : visitors) {
v.visit(gpr);
}
s.push(gpr);
}
}
} else {
Long knownSize = sizeCache.get(cl);
if (knownSize == null) {
knownSize = VM.current().sizeOf(o);
sizeCache.put(cl, knownSize);
}
cGpr.setSize(knownSize);
for (Field f : getAllReferenceFields(cl)) {
Object e = ObjectUtils.value(o, f);
if (e != null && visited.add(e)) {
GraphPathRecord gpr = new FieldGraphPathRecord(cGpr, f.getName(), cGpr.depth() + 1, e);
data.addRecord(gpr);
for (GraphVisitor v : visitors) {
v.visit(gpr);
}
s.push(gpr);
}
}
}
}
return data;
}
}