Package com.tangosol.coherence.transaction

Interface OptimisticNamedCache

  • All Superinterfaces:
    AutoCloseable, CacheMap, ConcurrentMap, InvocableMap, Map, NamedCache, NamedCollection, NamedMap, ObservableMap, QueryMap, Releasable
    public interface OptimisticNamedCache
extends NamedCache
    An extension to the NamedCache interface that adds support for optimistic transactions.

    Each operation has an associated predicate in the form of a Filter that is used to ensure that the value being updated is the expected value. Update and delete operations have explicit predicates where insert has an implicit predicate. Typically when a value is read and later modified in the scope of a transaction, a predicate is supplied to ensure that the value being modified is the same value that was previously read.

    When one of the optimistic operations are invoked, the predicate is applied to the latest committed value. If the predicate holds, a write lock is obtained for the row and the value is updated according to the operation. If the predicate fails a PredicateFailedException is thrown back to the caller.

    In addition to the PredicateFailedException, all mutating operations may throw a UnableToAcquireLockException if unable to acquire a write lock.

    Since:
    Coherence 3.6
    Author:
    jp, js 2009.2.10

    • Method Detail

      • update

        void update​(Object oKey,
            Object oValue,
            Filter validator)
        Update an existing value.
        Parameters:
        oKey - identifies the entry to update
        oValue - the new value
        validator - predicate used to ensure that the value being updated is the expected value. A null predicate will not check the current value or even that it exists.
        Throws:
        PredicateFailedException - if the predicate fails
        UnableToAcquireLockException - if unable to acquire a write lock

      • delete

        void delete​(Object oKey,
            Filter validator)
        Delete an existing value.
        Parameters:
        oKey - identifies the entry to delete
        validator - predicate used to ensure that the value being removed is the expected value. A null predicate will not check the current value or even that it exists.
        Throws:
        PredicateFailedException - if the predicate fails
        UnableToAcquireLockException - if unable to acquire a write lock

      • insert

        void insert​(Object oKey,
            Object oValue)
        Insert a new value. An implicit predicate is associated with the insert operation to ensure that the entry doesn't already exist.
        Parameters:
        oKey - identifies which row to insert
        oValue - the value of the inserted row
        Throws:
        PredicateFailedException - if the predicate fails
        UnableToAcquireLockException - if unable to acquire a write lock

      • put

        Object put​(Object oKey,
           Object oValue,
           long cMillis)
        Put with expiry, NamedCache.put(Object, Object, long), is currently not available when using a transactional cache.
        Specified by:
        put in interface CacheMap
        Specified by:
        put in interface NamedCache
        Parameters:
        oKey - key with which the specified value is to be associated
        oValue - value to be associated with the specified key
        cMillis - the number of milliseconds until the cache entry will expire, also referred to as the entry's "time to live"; pass CacheMap.EXPIRY_DEFAULT to use the cache's default time-to-live setting; pass CacheMap.EXPIRY_NEVER to indicate that the cache entry should never expire; this milliseconds value is not a date/time value, such as is returned from System.currentTimeMillis()
        Returns:
        previous value associated with specified key, or null if there was no mapping for key. A null return can also indicate that the map previously associated null with the specified key, if the implementation supports null values
        Throws:
        UnsupportedOperationException - always

      • lock

        boolean lock​(Object oKey,
             long cWait)
        Locking, ConcurrentMap.lock(Object, long), is currently not available when using a transactional cache.
        Specified by:
        lock in interface ConcurrentMap
        Parameters:
        oKey - key being locked
        cWait - the number of milliseconds to continue trying to obtain a lock; pass zero to return immediately; pass -1 to block the calling thread until the lock could be obtained
        Returns:
        true if the item was successfully locked within the specified time; false otherwise
        Throws:
        UnsupportedOperationException - always