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com.tangosol.util.processor
Class PriorityProcessor

java.lang.Object
com.tangosol.util.Base
com.tangosol.util.BitHelper
com.tangosol.util.ExternalizableHelper
com.tangosol.net.AbstractPriorityTask
com.tangosol.util.processor.PriorityProcessor

All Implemented Interfaces:

ExternalizableLite, PortableObject, PriorityTask, InvocableMap.EntryProcessor, java.io.Serializable

public class PriorityProcessor

extends AbstractPriorityTask

implements InvocableMap.EntryProcessor, ExternalizableLite, PortableObject

PriorityProcessor is used to explicitly control the scheduling priority and timeouts for execution of EntryProcessor-based methods.

For example, let's assume that there is a cache that belongs to a partitioned cache service configured with a task-timeout of 5 seconds. Also assume that there is a particular PreloadRequest processor that could take much longer to complete due to a large amount of database related processing. Then we could override the default task timeout value by using the PriorityProcessor as follows:

   PreloadRequest     procStandard = PreloadRequest.INSTANCE;
   PriorityProcessor  procPriority = new PriorityProcessor(procStandard);
   procPriority.setExecutionTimeoutMillis(PriorityTask.TIMEOUT_NONE);
   cache.processAll(setKeys, procPriority);
 

This is an advanced feature which should be used judiciously.

Since:

Coherence 3.3

Author:

gg 2007.03.20

Field Summary

Fields inherited from interface com.tangosol.net.PriorityTask

SCHEDULE_FIRST, SCHEDULE_IMMEDIATE, SCHEDULE_STANDARD, TIMEOUT_DEFAULT, TIMEOUT_NONE

Constructor Summary

PriorityProcessor()
Default constructor (necessary for the ExternalizableLite interface).

PriorityProcessor(InvocableMap.EntryProcessor processor)
Construct a PriorityProcessor.

Method Summary

InvocableMap.EntryProcessor	getProcessor() Obtain the underlying processor.
java.lang.Object	process(InvocableMap.Entry entry) Process a Map.Entry object.
java.util.Map	processAll(java.util.Set setEntries) Process a Set of InvocableMap.Entry objects.
void	readExternal(java.io.DataInput in) Restore the contents of this object by loading the object's state from the passed DataInput object.
void	readExternal(PofReader in) Restore the contents of a user type instance by reading its state using the specified PofReader object.
java.lang.String	toString() Return a human-readable description for this PriorityProcessor.
void	writeExternal(java.io.DataOutput out) Save the contents of this object by storing the object's state into the passed DataOutput object.
void	writeExternal(PofWriter out) Save the contents of a POF user type instance by writing its state using the specified PofWriter object.

Methods inherited from class com.tangosol.net.AbstractPriorityTask

getExecutionTimeoutMillis, getRequestTimeoutMillis, getSchedulingPriority, runCanceled, setExecutionTimeoutMillis, setRequestTimeoutMillis, setSchedulingPriority

Methods inherited from class com.tangosol.util.BitHelper

countBits, countBits, countBits, indexOfLSB, indexOfLSB, indexOfLSB, indexOfMSB, indexOfMSB, indexOfMSB, rotateLeft, rotateLeft, rotateLeft, rotateRight, rotateRight, rotateRight, toBitString, toBitString, toBitString

Constructor Detail

PriorityProcessor

public PriorityProcessor()

Default constructor (necessary for the ExternalizableLite interface).

PriorityProcessor

public PriorityProcessor(InvocableMap.EntryProcessor processor)

Construct a PriorityProcessor.

Parameters:

processor - the processor wrapped by this PriorityProcessor

Method Detail

process

public java.lang.Object process(InvocableMap.Entry entry)

Process a Map.Entry object.

Specified by:

process in interface InvocableMap.EntryProcessor

Parameters:

entry - the Entry to process 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.

Returns:

the result of the processing, if any

processAll

public java.util.Map processAll(java.util.Set 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.

Specified by:

processAll in interface InvocableMap.EntryProcessor

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

getProcessor

public InvocableMap.EntryProcessor getProcessor()

Obtain the underlying processor.

Returns:

the processor wrapped by this PriorityProcessor

toString

public java.lang.String toString()

Return a human-readable description for this PriorityProcessor.

Returns:

a String description of the PriorityProcessor

readExternal

public void readExternal(java.io.DataInput in)
                  throws java.io.IOException

Restore the contents of this object by loading the object's state from the passed DataInput object.

Specified by:

readExternal in interface ExternalizableLite

Overrides:

readExternal in class AbstractPriorityTask

Parameters:

in - the DataInput stream to read data from in order to restore the state of this object

Throws:

java.io.IOException - if an I/O exception occurs

java.io.NotActiveException - if the object is not in its initial state, and therefore cannot be deserialized into

writeExternal

public void writeExternal(java.io.DataOutput out)
                   throws java.io.IOException

Save the contents of this object by storing the object's state into the passed DataOutput object.

Specified by:

writeExternal in interface ExternalizableLite

Overrides:

writeExternal in class AbstractPriorityTask

Parameters:

out - the DataOutput stream to write the state of this object to

Throws:

java.io.IOException - if an I/O exception occurs

readExternal

public void readExternal(PofReader in)
                  throws java.io.IOException

Restore the contents of a user type instance by reading its state using the specified PofReader object.

The AbstractPriorityTask implementation reserves property indexes 0 - 9.

The PriorityProcessor implementation reserves property index 10.

Specified by:

readExternal in interface PortableObject

Overrides:

readExternal in class AbstractPriorityTask

Parameters:

in - the PofReader from which to read the object's state

Throws:

java.io.IOException - if an I/O error occurs

writeExternal

public void writeExternal(PofWriter out)
                   throws java.io.IOException

Save the contents of a POF user type instance by writing its state using the specified PofWriter object.

The AbstractPriorityTask implementation reserves property indexes 0 - 9.

The PriorityProcessor implementation reserves property index 10.

Specified by:

writeExternal in interface PortableObject

Overrides:

writeExternal in class AbstractPriorityTask

Parameters:

out - the PofWriter to which to write the object's state

Throws:

java.io.IOException - if an I/O error occurs

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