/**
* Rename the map.
*
* @param newMapName the name name
*/
public void renameMap(String newMapName) {
beforeWrite();
try {
store.renameMap(this, newMapName);
} finally {
afterWrite();
}
}
/** Remove all entries. */
public void clear() {
beforeWrite();
try {
root.removeAllRecursive();
newRoot(Page.createEmpty(this, store.getCurrentVersion()));
} finally {
afterWrite();
}
}
/**
* Remove a key-value pair, if the key exists.
*
* @param key the key (may not be null)
* @return the old value if the key existed, or null otherwise
*/
public V remove(Object key) {
beforeWrite();
try {
long writeVersion = store.getCurrentVersion();
Page p = copyOnWrite(root, writeVersion);
@SuppressWarnings("unchecked")
V result = (V) remove(p, writeVersion, key);
newRoot(p);
return result;
} finally {
afterWrite();
}
}
/** 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();
}
}
/**
* Add or replace a key-value pair.
*
* @param key the key (may not be null)
* @param value the value (may not be null)
* @return the old value if the key existed, or null otherwise
*/
@SuppressWarnings("unchecked")
public V put(K key, V value) {
DataUtils.checkArgument(value != null, "The value may not be null");
beforeWrite();
try {
long writeVersion = store.getCurrentVersion();
Page p = copyOnWrite(root, writeVersion);
p = splitRootIfNeeded(p, writeVersion);
Object result = put(p, writeVersion, key, value);
newRoot(p);
return (V) result;
} finally {
afterWrite();
}
}
/**
* 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();
}
}
