/**
* Get the row at the given index.
*
* @param at the index
* @return the row
*/
Row getRowAt(int at) {
Row r = rows[at];
if (r == null) {
if (firstOverflowPageId == 0) {
r = readRow(data, offsets[at], columnCount);
} else {
if (rowRef != null) {
r = rowRef.get();
if (r != null) {
return r;
}
}
PageStore store = index.getPageStore();
Data buff = store.createData();
int pageSize = store.getPageSize();
int offset = offsets[at];
buff.write(data.getBytes(), offset, pageSize - offset);
int next = firstOverflowPageId;
do {
PageDataOverflow page = index.getPageOverflow(next);
next = page.readInto(buff);
} while (next != 0);
overflowRowSize = pageSize + buff.length();
r = readRow(buff, 0, columnCount);
}
r.setKey(keys[at]);
if (firstOverflowPageId != 0) {
rowRef = new SoftReference<Row>(r);
} else {
rows[at] = r;
memoryChange(true, r);
}
}
return r;
}
public void moveTo(Session session, int newPos) {
PageStore store = index.getPageStore();
// load the pages into the cache, to ensure old pages
// are written
if (parentPageId != ROOT) {
store.getPage(parentPageId);
}
store.logUndo(this, data);
PageDataLeaf p2 = PageDataLeaf.create(index, newPos, parentPageId);
readAllRows();
p2.keys = keys;
p2.overflowRowSize = overflowRowSize;
p2.firstOverflowPageId = firstOverflowPageId;
p2.rowRef = rowRef;
p2.rows = rows;
if (firstOverflowPageId != 0) {
p2.rows[0] = getRowAt(0);
}
p2.entryCount = entryCount;
p2.offsets = offsets;
p2.start = start;
p2.remapChildren(getPos());
p2.writeData();
p2.data.truncate(index.getPageStore().getPageSize());
store.update(p2);
if (parentPageId == ROOT) {
index.setRootPageId(session, newPos);
} else {
PageDataNode p = (PageDataNode) store.getPage(parentPageId);
p.moveChild(getPos(), newPos);
}
store.free(getPos());
}
public PageDelegateIndex(
TableData table,
int id,
String name,
IndexType indexType,
PageDataIndex mainIndex,
int headPos,
Session session)
throws SQLException {
IndexColumn[] columns =
IndexColumn.wrap(new Column[] {table.getColumn(mainIndex.getMainIndexColumn())});
this.initBaseIndex(table, id, name, columns, indexType);
this.mainIndex = mainIndex;
if (!database.isPersistent() || id < 0) {
throw Message.throwInternalError("" + name);
}
PageStore store = database.getPageStore();
store.addIndex(this);
if (headPos == Index.EMPTY_HEAD) {
store.addMeta(this, session);
}
}