Package com.tangosol.util.processor

Class ConditionalPutAll<K,V>

java.lang.Object
com.tangosol.util.Base
com.tangosol.util.processor.AbstractProcessor<K,V,V>
com.tangosol.util.processor.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:

  • Field Details

    • 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 Details

    • 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 Details

    • process

      public V process(InvocableMap.Entry<K,V> entry)
      Process a Map.Entry object.

      Note: if this method throws an exception, all modifications to the supplied entry or any other entries retrieved via the BackingMapContext.getBackingMapEntry(java.lang.Object) API will be rolled back leaving all underlying values unchanged.

      Specified by:
      process in interface InvocableMap.EntryProcessor<K,V,V>
      Parameters:
      entry - the Entry to process
      Returns:
      the result of the processing, if any

    • 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

    • 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