Package com.tangosol.util.processor

Class ConditionalPutAll<K,​V>

  • All Implemented Interfaces:
    ExternalizableLite, PortableObject, InvocableMap.EntryProcessor<K,​V,​V>, Serializable
    public class ConditionalPutAll<K,​V>
extends AbstractProcessor<K,​V,​V>
implements ExternalizableLite, PortableObject
    ConditionalPutAll is an EntryProcessor that performs a Entry.setValue operation for multiple entries that satisfy the specified condition.

    Consider such methods of the ConcurrentMap interface as replace(key, value) and putIfAbsent(key, value). While the regular put(key, value) method has the "multi-put" flavor putAll(map), there are no analogous "bulk" operations for those ConcurrentMap methods. The ConditionalPutAll processor provides the corresponding functionality when used in conjunction with the invokeAll(keys, processor) API. For example, the replaceAll(map) method could be implemented as: 

       filter = PresentFilter.INSTANCE;
   cache.invokeAll(map.keySet(), new ConditionalPutAll(filter, map));
    and the putAllIfAbsent(map) could be done by inverting the filter: 
       filter = new NotFilter(PresentFilter.INSTANCE);

    Obviously, using more specific, fine-tuned filters may provide additional flexibility and efficiency allowing the multi-put operations to be performed conditionally on values of specific attributes (or even calculations) instead of a simple existence check.

    Since:
    Coherence 3.2
    Author:
    gg 2006.04.28
    See Also:
    Serialized Form

    • Field Detail

      • m_filter

        protected Filter m_filter
        The underlying filter.

      • m_map

        protected Map<? extends K,​? extends V> m_map
        Specifies the map of new values.

    • Constructor Detail

      • ConditionalPutAll

        public ConditionalPutAll()
        Default constructor (necessary for the ExternalizableLite interface).

      • ConditionalPutAll

        public ConditionalPutAll​(Filter filter,
                         Map<? extends K,​? extends V> map)
        Construct a ConditionalPutAll processor that updates an entry with a new value if and only if the filter applied to the entry evaluates to true. The new value is extracted from the specified map based on the entry's key.
        Parameters:
        filter - the filter to evaluate all supplied entries
        map - a map of values to update entries with

    • Method Detail

      • processAll

        public Map<K,​V> processAll​(Set<? extends InvocableMap.Entry<K,​V>> setEntries)
        Process a Set of InvocableMap.Entry objects. This method is semantically equivalent to: 
           Map mapResults = new ListMap();
   for (Iterator iter = setEntries.iterator(); iter.hasNext(); )
       {
       Entry entry = (Entry) iter.next();
       mapResults.put(entry.getKey(), process(entry));
       }
   return mapResults;

        Note: if processAll() call throws an exception, only the entries that were removed from the setEntries would be considered successfully processed and the corresponding changes made to the underlying Map; changes made to the remaining entries or any other entries obtained from BackingMapContext.getBackingMapEntry(java.lang.Object) will not be processed. Note: As of Coherence 12.2.1, this method simply delegates to the default processAll implementation in InvocableMap.EntryProcessor.

        Specified by:
        processAll in interface InvocableMap.EntryProcessor<K,​V,​V>
        Overrides:
        processAll in class AbstractProcessor<K,​V,​V>
        Parameters:
        setEntries - a Set of InvocableMap.Entry objects to process
        Returns:
        a Map containing the results of the processing, up to one entry for each InvocableMap.Entry that was processed, keyed by the keys of the Map that were processed, with a corresponding value being the result of the processing for each key

      • equals

        public boolean equals​(Object o)
        Compare the ConditionalPutAll with another object to determine equality.
        Overrides:
        equals in class Object
        Returns:
        true iff this ConditionalPutAll and the passed object are equivalent ConditionalPutAll

      • hashCode

        public int hashCode()
        Determine a hash value for the ConditionalPutAll object according to the general Object.hashCode() contract.
        Overrides:
        hashCode in class Object
        Returns:
        an integer hash value for this ConditionalPutAll object

      • toString

        public String toString()
        Return a human-readable description for this ConditionalPutAll.
        Overrides:
        toString in class Object
        Returns:
        a String description of the ConditionalPutAll

      • readExternal

        public void readExternal​(DataInput in)
                  throws IOException
        Restore the contents of this object by loading the object's state from the passed DataInput object.
        Specified by:
        readExternal in interface ExternalizableLite
        Parameters:
        in - the DataInput stream to read data from in order to restore the state of this object
        Throws:
        IOException - if an I/O exception occurs
        NotActiveException - if the object is not in its initial state, and therefore cannot be deserialized into

      • writeExternal

        public void writeExternal​(DataOutput out)
                   throws IOException
        Save the contents of this object by storing the object's state into the passed DataOutput object.
        Specified by:
        writeExternal in interface ExternalizableLite
        Parameters:
        out - the DataOutput stream to write the state of this object to
        Throws:
        IOException - if an I/O exception occurs

      • readExternal

        public void readExternal​(PofReader in)
                  throws IOException
        Restore the contents of a user type instance by reading its state using the specified PofReader object.
        Specified by:
        readExternal in interface PortableObject
        Parameters:
        in - the PofReader from which to read the object's state
        Throws:
        IOException - if an I/O error occurs

      • writeExternal

        public void writeExternal​(PofWriter out)
                   throws IOException
        Save the contents of a POF user type instance by writing its state using the specified PofWriter object.
        Specified by:
        writeExternal in interface PortableObject
        Parameters:
        out - the PofWriter to which to write the object's state
        Throws:
        IOException - if an I/O error occurs