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- Rewrote remove() and removeNode(): removeNode() just releases the

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child node, but *never* deletes it from the database. remove()
    actually deletes the node from the database and also releases it
    from its parent.
    This affects HopObject.remove() and HopObject.remove(HopObject),
    which use these methods. From now on, the only way to delete a
    HopObject from db is to use the remove() function without arguments.
    HopObject.remove(HopObject) should be used to
       - remove a child object from an embedded db collection without
         deleting it
       - removing a hopobject from a relational db collection with
         cachemode = aggressive if the collection does not belong to the
         child object's parent.
- Do not return on-demand nodes (groupby, accessname) in getProperty().
- Avoid creating loops in parent chain when creating cyclic references
    on transient objects before committing them to db
- Removed unused links vector and code
- Rename Enumerations because enum is a reserved word in Java 1.5
This commit is contained in:
hns 2004-01-14 16:58:38 +00:00
parent 237b785fa9
commit 6a1466b0bc
1 changed files with 54 additions and 107 deletions
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161
src/helma/objectmodel/db/Node.java
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@ -45,8 +45,6 @@ public final class Node implements INode, Serializable {
// Named subnodes (properties) of this node
private Hashtable propMap;
// Other nodes that link to this node. Used for reference counting/checking
private List links;
protected long created;
protected long lastmodified;
private String id;
@ -193,7 +191,8 @@ public final class Node implements INode, Serializable {
lastmodified = in.readLong();
subnodes = (ExternalizableVector) in.readObject();
links = (ExternalizableVector) in.readObject();
// left-over from links vector
in.readObject();
propMap = (Hashtable) in.readObject();
anonymous = in.readBoolean();
prototype = (String) in.readObject();
@ -223,7 +222,8 @@ public final class Node implements INode, Serializable {
out.writeObject(subnodes);
}
out.writeObject(links);
// left-over from links vector
out.writeObject(null);
out.writeObject(propMap);
out.writeBoolean(anonymous);
out.writeObject(prototype);
@ -907,7 +907,7 @@ public final class Node implements INode, Serializable {
}
}
if (!"root".equalsIgnoreCase(node.getPrototype())) {
if (node != this && !"root".equalsIgnoreCase(node.getPrototype())) {
// avoid calling getParent() because it would return bogus results
// for the not-anymore transient node
Node nparent = (node.parentHandle == null) ? null
@ -919,11 +919,6 @@ public final class Node implements INode, Serializable {
((state != TRANSIENT) && (nparent.getState() == TRANSIENT))) {
node.setParent(this);
node.anonymous = true;
} else if ((nparent != null) && ((nparent != this) || !node.anonymous)) {
// this makes the additional job of addLink, registering that we have
// a link to a node in our subnodes that actually sits somewhere else.
// This means that addLink and addNode are actually the same now.
node.registerLinkFrom(this);
}
}
}
@ -995,30 +990,6 @@ public final class Node implements INode, Serializable {
return n;
}
/**
* register a node that links to this node so we can notify it when we cease to exist.
* this is only necessary if we are a non-relational node, since for relational nodes
* the referring object will notice that we've gone at runtime.
*/
protected void registerLinkFrom(Node from) {
if (isRelational()) {
return;
}
if (from.getState() == TRANSIENT) {
return;
}
if (links == null) {
links = new ExternalizableVector();
}
Object fromHandle = from.getHandle();
if (!links.contains(fromHandle)) {
links.add(fromHandle);
}
}
/**
* This implements the getChild() method of the IPathElement interface
@ -1046,7 +1017,7 @@ public final class Node implements INode, Serializable {
return getSubnode(name);
} else {
// no dbmapping - just try child collection first, then named property.
IPathElement child = getSubnode(name);
INode child = getSubnode(name);
if (child == null) {
child = getNode(name);
@ -1071,9 +1042,8 @@ public final class Node implements INode, Serializable {
* @return ...
*/
public INode getSubnode(String subid) {
// System.err.println ("GETSUBNODE : "+this+" > "+subid);
if ("".equals(subid)) {
return this;
if (subid == null || subid.length() == 0) {
return null;
}
Node retval = null;
@ -1205,14 +1175,11 @@ public final class Node implements INode, Serializable {
* @return ...
*/
public boolean remove() {
checkWriteLock();
try {
getParent().removeNode(this);
} catch (Exception x) {
return false;
INode parent = getParent();
if (parent != null) {
parent.removeNode(this);
}
deepRemoveNode();
return true;
}
@ -1222,30 +1189,8 @@ public final class Node implements INode, Serializable {
* @param node ...
*/
public void removeNode(INode node) {
// nmgr.logEvent ("removing: "+ node);
Node n = (Node) node;
checkWriteLock();
n.checkWriteLock();
// need to query parent before releaseNode is called, since this may change the parent
// to the next option described in the type.properties _parent info
INode parent = n.getParent();
releaseNode(n);
if (parent == this) {
n.deepRemoveNode();
} else {
// removed just a link, not the main node.
if (n.links != null) {
n.links.remove(getHandle());
if (n.state == CLEAN) {
n.markAs(MODIFIED);
}
}
}
}
/**
@ -1253,11 +1198,19 @@ public final class Node implements INode, Serializable {
* The logical stuff necessary for keeping data consistent is done in removeNode().
*/
protected void releaseNode(Node node) {
INode parent = node.getParent();
checkWriteLock();
node.checkWriteLock();
boolean removed = false;
if (subnodes != null) {
subnodes.remove(node.getHandle());
removed = subnodes.remove(node.getHandle());
}
registerSubnodeChange();
if (removed)
registerSubnodeChange();
// check if subnodes are also accessed as properties. If so, also unset the property
if ((dbmap != null) && (node.dbmap != null)) {
@ -1276,6 +1229,11 @@ public final class Node implements INode, Serializable {
}
}
if (parent == this) {
// node.markAs(MODIFIED);
node.setParentHandle(null);
}
// If subnodes are relational no need to mark this node as modified
if (ignoreSubnodeChange()) {
return;
@ -1295,25 +1253,17 @@ public final class Node implements INode, Serializable {
* it can tell which nodes are actual children and which are just linked in.
*/
protected void deepRemoveNode() {
// notify nodes that link to this node being deleted.
int l = (links == null) ? 0 : links.size();
for (int i = 0; i < l; i++) {
NodeHandle lhandle = (NodeHandle) links.get(i);
Node link = lhandle.getNode(nmgr);
if (link != null) {
link.releaseNode(this);
}
}
// tell all nodes that are properties of n that they are no longer used as such
if (propMap != null) {
for (Enumeration e2 = propMap.elements(); e2.hasMoreElements();) {
Property p = (Property) e2.nextElement();
for (Enumeration en = propMap.elements(); en.hasMoreElements();) {
Property p = (Property) en.nextElement();
if ((p != null) && (p.getType() == Property.NODE)) {
p.unregisterNode();
Node n = (Node) p.getNodeValue();
if (n != null && !n.isRelational() && n.getParent() == this) {
n.deepRemoveNode();
}
}
}
}
@ -1324,8 +1274,8 @@ public final class Node implements INode, Serializable {
Vector v = new Vector();
// remove modifies the Vector we are enumerating, so we are extra careful.
for (Enumeration e3 = getSubnodes(); e3.hasMoreElements();) {
v.add(e3.nextElement());
for (Enumeration en = getSubnodes(); en.hasMoreElements();) {
v.add(en.nextElement());
}
int m = v.size();
@ -1335,8 +1285,8 @@ public final class Node implements INode, Serializable {
// a cascading delete on that criterium for relational nodes.
Node n = (Node) v.get(i);
if (!n.isRelational()) {
removeNode(n);
if (!n.isRelational() && n.getParent() == this) {
n.deepRemoveNode();
}
}
}
@ -1668,7 +1618,7 @@ public final class Node implements INode, Serializable {
// 3) try to get the property from the database via accessname, if defined
// (only do this if accessname or groupby is specified)
if (rel == null && dbmap != null && state != TRANSIENT) {
/* if (rel == null && dbmap != null && state != TRANSIENT) {
rel = dbmap.getSubnodeRelation();
if (rel != null && rel.createOnDemand()) {
@ -1681,10 +1631,11 @@ public final class Node implements INode, Serializable {
n.name = propname;
n.anonymous = false;
}
return new Property(propname, this, n);
}
}
}
} */
// 4) nothing to be found - return null
return null;
@ -2181,10 +2132,20 @@ public final class Node implements INode, Serializable {
// check if the main identity of this node is as a named property
// or as an anonymous node in a collection
if ((n.parentHandle == null) && !"root".equalsIgnoreCase(n.getPrototype())) {
n.setParent(this);
n.name = propname;
n.anonymous = false;
if (n != this && !"root".equalsIgnoreCase(n.getPrototype())) {
// avoid calling getParent() because it would return bogus results
// for the not-anymore transient node
Node nparent = (n.parentHandle == null) ? null
: n.parentHandle.getNode(nmgr);
// if the node doesn't have a parent yet, or it has one but it's
// transient while we are persistent, make this the nodes new parent.
if ((nparent == null) ||
((state != TRANSIENT) && (nparent.getState() == TRANSIENT))) {
n.setParent(this);
n.name = propname;
n.anonymous = false;
}
}
propname = propname.trim();
@ -2238,19 +2199,10 @@ public final class Node implements INode, Serializable {
}
}
/* if (rel != null && rel.reftype == Relation.REFERENCE && !rel.usesPrimaryKey ()) {
// if the relation for this property doesn't use the primary key of the value object, make a
// secondary key object with the proper db column
String kval = n.getString (rel.otherType.columnNameToProperty (rel.getRemoteField ()), false);
prop.nhandle = new NodeHandle (new DbKey (n.getDbMapping (), kval, rel.getRemoteField ()));
} */
// don't check node in transactor cache if node is transient -
// this is done anyway when the node becomes persistent.
if (n.state != TRANSIENT) {
// check node in with transactor cache
// String nID = n.getID();
// DbMapping dbm = n.getDbMapping ();
Transactor tx = (Transactor) Thread.currentThread();
// tx.visitCleanNode (new DbKey (dbm, nID), n);
@ -2297,10 +2249,6 @@ public final class Node implements INode, Serializable {
if (p != null) {
checkWriteLock();
if (p.getType() == Property.NODE) {
p.unregisterNode();
}
if (relational) {
p.setStringValue(null);
}
@ -2502,7 +2450,6 @@ public final class Node implements INode, Serializable {
public void dump() {
System.err.println("subnodes: " + subnodes);
System.err.println("properties: " + propMap);
System.err.println("links: " + links);
}
}