Java中的Sizeof(二)

2019-11-18 14:30:00

字體：大中小

來源：轉載

供稿：網友

　　在做了所有這些預備之后，下面就是這種圖形遍歷的標準實現：

public static IObjectPRofileNode profile (Object obj)
{
final IdentityHashMap visited = new IdentityHashMap ();

final ObjectProfileNode root = createProfileTree (obj, visited,
CLASS_METADATA_CACHE);
finishProfileTree (root);

return root;
}

private static ObjectProfileNode createProfileTree (Object obj,
IdentityHashMap visited,
Map metadataMap)
{
final ObjectProfileNode root = new ObjectProfileNode (null, obj, null);

final LinkedList queue = new LinkedList ();

queue.addFirst (root);
visited.put (obj, root);

final Class accessPrivilegedAction caAction =
new ClassAccessPrivilegedAction ();
final FieldAccessPrivilegedAction faAction =
new FieldAccessPrivilegedAction ();

while (! queue.isEmpty ())
{
final ObjectProfileNode node = (ObjectProfileNode) queue.removeFirst ();

obj = node.m_obj;
final Class objClass = obj.getClass ();

if (objClass.isArray ())
{
final int arrayLength = Array.getLength (obj);
final Class componentType = objClass.getComponentType ();

// Add shell pseudo-node:
final AbstractShellProfileNode shell =
new ArrayShellProfileNode (node, objClass, arrayLength);
shell.m_size = sizeofArrayShell (arrayLength, componentType);

node.m_shell = shell;
node.addFieldRef (shell);

if (! componentType.isPrimitive ())
{
// Traverse each array slot:
for (int i = 0; i < arrayLength; ++ i)
{
final Object ref = Array.get (obj, i);

if (ref != null)
{
ObjectProfileNode child =
(ObjectProfileNode) visited.get (ref);
if (child != null)
++ child.m_refcount;
else

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