The main benefit of this class over using plain {@link org.cliffc.high_scale_lib.NonBlockingHashMap} with {@link Long} keys isthat it avoids the auto-boxing and unboxing costs. Since auto-boxing is automatic, it is easy to accidentally cause auto-boxing and negate the space and speed benefits.
This class obeys the same functional specification as {@link java.util.Hashtable}, and includes versions of methods corresponding to each method of Hashtable. However, even though all operations are thread-safe, operations do not entail locking and there is not any support for locking the entire table in a way that prevents all access. This class is fully interoperable with Hashtable in programs that rely on its thread safety but not on its synchronization details.
Operations (including put) generally do not block, so may overlap with other update operations (including other puts and removes). Retrievals reflect the results of the most recently completed update operations holding upon their onset. For aggregate operations such as putAll, concurrent retrievals may reflect insertion or removal of only some entries. Similarly, Iterators and Enumerations return elements reflecting the state of the hash table at some point at or since the creation of the iterator/enumeration. They do not throw {@link ConcurrentModificationException}. However, iterators are designed to be used by only one thread at a time.
Very full tables, or tables with high reprobe rates may trigger an internal resize operation to move into a larger table. Resizing is not terribly expensive, but it is not free either; during resize operations table throughput may drop somewhat. All threads that visit the table during a resize will 'help' the resizing but will still be allowed to complete their operation before the resize is finished (i.e., a simple 'get' operation on a million-entry table undergoing resizing will not need to block until the entire million entries are copied).
This class and its views and iterators implement all of the optional methods of the {@link Map} and {@link Iterator}interfaces.
Like {@link Hashtable} but unlike {@link HashMap}, this class does not allow null to be used as a value. @since 1.5 @author Cliff Click @param < TypeV> the type of mapped values
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