/**
* Get the smallest or largest key using the given bounds.
*
* @param key the key
* @param min whether to retrieve the smallest key
* @param excluding if the given upper/lower bound is exclusive
* @return the key, or null if the map is empty
*/
protected K getMinMax(K key, boolean min, boolean excluding) {
checkOpen();
if (size() == 0) {
return null;
}
return getMinMax(root, key, min, excluding);
}
/**
* Get the index of the given key in the map.
*
* <p>This is a O(log(size)) operation.
*
* <p>If the key was found, the returned value is the index in the key array. If not found, the
* returned value is negative, where -1 means the provided key is smaller than any keys. See also
* Arrays.binarySearch.
*
* @param key the key
* @return the index
*/
public long getKeyIndex(K key) {
checkOpen();
if (size() == 0) {
return -1;
}
Page p = root;
long offset = 0;
while (true) {
int x = p.binarySearch(key);
if (p.isLeaf()) {
if (x < 0) {
return -offset + x;
}
return offset + x;
}
if (x < 0) {
x = -x - 1;
} else {
x++;
}
for (int i = 0; i < x; i++) {
offset += p.getCounts(i);
}
p = p.getChildPage(x);
}
}
/**
* Get the key at the given index.
*
* <p>This is a O(log(size)) operation.
*
* @param index the index
* @return the key
*/
@SuppressWarnings("unchecked")
public K getKey(long index) {
checkOpen();
if (index < 0 || index >= size()) {
return null;
}
Page p = root;
long offset = 0;
while (true) {
if (p.isLeaf()) {
if (index >= offset + p.getKeyCount()) {
return null;
}
return (K) p.getKey((int) (index - offset));
}
int i = 0, size = p.getChildPageCount();
for (; i < size; i++) {
long c = p.getCounts(i);
if (index < c + offset) {
break;
}
offset += c;
}
if (i == size) {
return null;
}
p = p.getChildPage(i);
}
}
/**
* This method is called before writing to the map. The default implementation checks whether
* writing is allowed, and tries to detect concurrent modification.
*
* @throws UnsupportedOperationException if the map is read-only, or if another thread is
* concurrently writing
*/
protected void beforeWrite() {
if (readOnly) {
checkOpen();
throw DataUtils.newUnsupportedOperationException("This map is read-only");
}
checkConcurrentWrite();
writing = true;
store.beforeWrite();
}
/** Remove all entries, and close the map. */
public void removeMap() {
checkOpen();
if (this == store.getMetaMap()) {
return;
}
beforeWrite();
try {
root.removeAllRecursive();
store.removeMap(id);
close();
} finally {
afterWrite();
}
}
/**
* Get the first (lowest) or last (largest) key.
*
* @param first whether to retrieve the first key
* @return the key, or null if the map is empty
*/
@SuppressWarnings("unchecked")
protected K getFirstLast(boolean first) {
checkOpen();
if (size() == 0) {
return null;
}
Page p = root;
while (true) {
if (p.isLeaf()) {
return (K) p.getKey(first ? 0 : p.getKeyCount() - 1);
}
p = p.getChildPage(first ? 0 : p.getChildPageCount() - 1);
}
}
public Set<K> keySet() {
checkOpen();
final MVMap<K, V> map = this;
final Page root = this.root;
return new AbstractSet<K>() {
@Override
public Iterator<K> iterator() {
return new Cursor<K>(map, root, null);
}
@Override
public int size() {
return MVMap.this.size();
}
@Override
public boolean contains(Object o) {
return MVMap.this.containsKey(o);
}
};
}
public long getSize() {
checkOpen();
return root.getTotalCount();
}
/**
* Iterate over all keys.
*
* @param from the first key to return
* @return the iterator
*/
public Cursor<K> keyIterator(K from) {
checkOpen();
return new Cursor<K>(this, root, from);
}
/**
* Get a value.
*
* @param key the key
* @return the value, or null if not found
*/
@SuppressWarnings("unchecked")
public V get(Object key) {
checkOpen();
return (V) binarySearch(root, key);
}