/**
* Find the value associated with the given key, or the entry immediately following this key in
* the ordered BTree.
*
* @param key Lookup key.
* @return Value associated with the key, or a greater entry, or null if no greater entry was
* found.
*/
public synchronized Tuple findGreaterOrEqual(Object key) throws IOException {
Tuple tuple;
TupleBrowser browser;
if (key == null) {
// there can't be a key greater than or equal to "null"
// because null is considered an infinite key.
return null;
}
tuple = new Tuple(null, null);
browser = browse(key);
if (browser.getNext(tuple)) {
return tuple;
} else {
return null;
}
}
/**
* Find the value associated with the given key.
*
* @param key Lookup key.
* @return Value associated with the key, or null if not found.
*/
public synchronized Object find(Object key) throws IOException {
if (key == null) {
throw new IllegalArgumentException("Argument 'key' is null");
}
BPage rootPage = getRoot();
if (rootPage == null) {
return null;
}
Tuple tuple = new Tuple(null, null);
TupleBrowser browser = rootPage.find(_height, key);
if (browser.getNext(tuple)) {
// find returns the matching key or the next ordered key, so we must
// check if we have an exact match
if (_comparator.compare(key, tuple.getKey()) != 0) {
return null;
} else {
return tuple.getValue();
}
} else {
return null;
}
}