public StructuralSummaryNode next() throws IOException, DBException // for Iterator
{
// read record from file
// transform into ssNode
int CID;
int qNameLen;
String qName;
byte[] qNameSeq;
int parentCID;
StructuralSummaryNode currentNode = new StructuralSummaryNode();
int nextPage; // needed in case that data is written in more than one page
while (true) {
// if(unTakenNodes!=0 &&XBufferChannel.position()+2*Settings.sizeOfInt<=Settings.pageSize)
// agar dorost bkhunim har bar position sare yek record mi iste:
if (unTakenNodes != 0 && xBufferChannel.position() < freeOffset) {
// bayd daghigh tar chek bshe.
// stroage format in ssIndex: cid(int),qlen(int),qSeq(byte array),parentCId(int)
CID = xBufferChannel.getInt();
logManager.LogManager.log(1, "CID: " + CID);
qNameLen = xBufferChannel.getInt();
int reqSpace = qNameLen + Settings.sizeOfInt;
int capacity = Settings.pageSize - xBufferChannel.position();
if (reqSpace <= capacity) {
qNameSeq = new byte[qNameLen];
xBufferChannel.get(qNameSeq, 0, qNameLen);
qName = new String(qNameSeq);
parentCID = xBufferChannel.getInt();
currentNode.setCID(CID);
currentNode.setParentCID(parentCID);
currentNode.setQName(qName);
unTakenNodes--;
return currentNode; // return breaks loop!
}
} else {
// if(unTakenNodes==0)//in k ghalate baz :(
// { return null; }
// else //if(XBufferChannel.position()+2*Settings.sizeOfInt>Settings.pageSize)
// { //goTOnextPAge;
xBufferChannel.position(Settings.nextPagePos);
nextPage = xBufferChannel.getInt();
bufMngr.unpinBuffer(xBufferChannel);
if (nextPage > 0) {
loadSSPage(nextPage); // prepares XBufferChannel and loads page into it.
// System.out.println("loaded:"+nextPage);
} else return null;
workingPage = nextPage;
xBufferChannel.position(
Settings.dataStartPos); // instead of calling open(somehow opens nextpage)
// }
}
} // end while
}
public int getLevel() {
if (levelComputed) return level;
StructuralSummaryNode node = this;
int level = 0;
while (node.getParent() != null) {
level++;
node = node.getParent();
}
levelComputed = true;
this.level = level;
return level;
}
public boolean hasChild(StructuralSummaryNode newborn) {
boolean present = false; // newborn exists in list or not
for (StructuralSummaryNode child : childrenList) {
if (child.getCID() == newborn.getCID()
&& (child.getQName() == null
? newborn.getQName() == null
: child.getQName().equals(newborn.getQName()))) {
present = true;
break;
}
}
return present;
}
//// end of copied//////////////////////////////////
public void appendChild(StructuralSummaryNode childNode) {
childNode.setParent(this);
childrenList.add(childNode);
}
public void setParent(StructuralSummaryNode parent) {
this.parent = parent;
this.parentCID = parent.getCID();
this.levelComputed = false;
}