/**
* Use the new root page from now on.
*
* @param newRoot the new root page
*/
protected void newRoot(Page newRoot) {
if (root != newRoot) {
removeUnusedOldVersions();
if (root.getVersion() != newRoot.getVersion()) {
ArrayList<Page> list = oldRoots;
if (list.size() > 0) {
Page last = list.get(list.size() - 1);
if (last.getVersion() != root.getVersion()) {
list.add(root);
}
} else {
list.add(root);
}
store.markChanged(this);
}
root = newRoot;
}
}
/**
* Rollback to the given version.
*
* @param version the version
*/
void rollbackTo(long version) {
beforeWrite();
try {
removeUnusedOldVersions();
if (version <= createVersion) {
// the map is removed later
} else if (root.getVersion() >= version) {
// iterating in descending order -
// this is not terribly efficient if there are many versions
ArrayList<Page> list = oldRoots;
while (list.size() > 0) {
int i = list.size() - 1;
Page p = list.get(i);
root = p;
list.remove(i);
if (p.getVersion() < version) {
break;
}
}
}
} finally {
afterWrite();
}
}