com.tangosol.util
Class InvocableMapHelper

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.util.InvocableMapHelper

public abstract class InvocableMapHelper
extends Base

Helper methods for InvocableMap implementations and Filter related evaluation.

Since:

Coherence 3.1

Author:

gg 2005.10.24

Nested Class Summary

static class

InvocableMapHelper.SimpleEntry Simple implementation of the InvocableMap.Entry interface.

Field Summary

static Converter

ENTRY_TO_KEY_CONVERTER Trivial Entry-to-Key converter.

Constructor Summary

InvocableMapHelper()

Method Summary

static boolean	evaluateEntry(Filter filter, Map.Entry entry) Check if the entry passes the filters evaulation.
static boolean	evaluateEntry(Filter filter, Object oKey, Object oValue) Check if an entry, expressed as a key and value, passes the filters evaulation.
static Object	extractFromEntry(ValueExtractor extractor, Map.Entry entry) Extract a value from the specified entry using the specified extractor.
static Map	invokeAllLocked(ConcurrentMap map, Set setEntries, InvocableMap.EntryProcessor agent) Invoke the passed EntryProcessor against the entries specified by the passed map and entries.
static Object	invokeLocked(ConcurrentMap map, InvocableMap.Entry entry, InvocableMap.EntryProcessor agent) Invoke the passed EntryProcessor against the specified Entry.
static List	lockAll(ConcurrentMap map, Collection collKeys, long cWait) Attempt to lock all the specified keys within a specified period of time.
static InvocableMapHelper.SimpleEntry	makeEntry(Map map, Object oKey) Create a SimpleEntry object for the specified map and the key.
static Set	makeEntrySet(Collection collEntries) Create a set of read-only SimpleEntry objects for the specified collection of Map.Entry objects.
static Set	makeEntrySet(Map map, Collection collKeys, boolean fReadOnly) Create a set of SimpleEntry objects for the specified map and the key collection.
static Set	query(Map map, Filter filter, boolean fEntries, boolean fSort, Comparator comparator) Generic implementation of the QueryMap API.
static void	unlockAll(ConcurrentMap map, Collection collKeys) Unlock all the specified keys.

Field Detail

ENTRY_TO_KEY_CONVERTER

public static final Converter ENTRY_TO_KEY_CONVERTER

Trivial Entry-to-Key converter.

Constructor Detail

InvocableMapHelper

public InvocableMapHelper()

Method Detail

invokeLocked

public static Object invokeLocked(ConcurrentMap map,
                                  InvocableMap.Entry entry,
                                  InvocableMap.EntryProcessor agent)

Invoke the passed EntryProcessor against the specified Entry. The invocation is made thread safe by locking the corresponding key on the map.

Parameters:

map - the ConcurrentMap that the EntryProcessor works against

entry - the InvocableMap.Entry to process; it is not required to exist within the Map

agent - the EntryProcessor to use to process the specified key

Returns:

the result of the invocation as returned from the EntryProcessor

invokeAllLocked

public static Map invokeAllLocked(ConcurrentMap map,
                                  Set setEntries,
                                  InvocableMap.EntryProcessor agent)

Invoke the passed EntryProcessor against the entries specified by the passed map and entries. The invocation is made thread safe by locking the corresponding keys on the map. If an attempt to lock all the entries at once fails, they will be processed individually one-by-one.

Parameters:

map - the ConcurrentMap that the EntryProcessor works against

setEntries - a set of InvocableMap.Entry objects to process

agent - the EntryProcessor to use to process the specified keys

Returns:

a Map containing the results of invoking the EntryProcessor against each of the specified entry

lockAll

public static List lockAll(ConcurrentMap map,
                           Collection collKeys,
                           long cWait)

Attempt to lock all the specified keys within a specified period of time.

Parameters:

map - the ConcurrentMap to use

collKeys - a collection of keys to lock

cWait - the number of milliseconds to continue trying to obtain locks; pass zero to return immediately; pass -1 to block the calling thread until the lock could be obtained

Returns:

a List containing all the locked keys in the order opposite to the locking order (LIFO); null if timeout has occurred

unlockAll

public static void unlockAll(ConcurrentMap map,
                             Collection collKeys)

Unlock all the specified keys.

Parameters:

map - the ConcurrentMap to use

collKeys - a collection of keys to unlock

makeEntry

public static InvocableMapHelper.SimpleEntry makeEntry(Map map,
                                                       Object oKey)

Create a SimpleEntry object for the specified map and the key.

Parameters:

map - the ConcurrentMap to create entries for

oKey - the key to create an entry for; the key is not required to exist within the Map

Returns:

a SimpleEntry object

makeEntrySet

public static Set makeEntrySet(Map map,
                               Collection collKeys,
                               boolean fReadOnly)

Create a set of SimpleEntry objects for the specified map and the key collection.

Parameters:

map - the Map to create entries for

collKeys - collection of keys to create entries for; these keys are not required to exist within the Map

fReadOnly - if true, the returned entries will be marked as read-only

Returns:

a Set of SimpleEntry objects

makeEntrySet

public static Set makeEntrySet(Collection collEntries)

Create a set of read-only SimpleEntry objects for the specified collection of Map.Entry objects.

Parameters:

collEntries - collection of Map.Entry objects to create SimpleEntry objects for

Returns:

a Set of SimpleEntry objects

evaluateEntry

public static boolean evaluateEntry(Filter filter,
                                    Map.Entry entry)

Check if the entry passes the filters evaulation.

Parameters:

filter - the filter to evaulate against

entry - a key value pair to filter

Returns:

true if the entry passes the filter, false otherwise

evaluateEntry

public static boolean evaluateEntry(Filter filter,
                                    Object oKey,
                                    Object oValue)

Check if an entry, expressed as a key and value, passes the filters evaulation.

Parameters:

filter - the filter to evaluate against

oKey - the key for the entry

oValue - the value for the entry

Returns:

true if the entry passes the filter, false otherwise

extractFromEntry

public static Object extractFromEntry(ValueExtractor extractor,
                                      Map.Entry entry)

Extract a value from the specified entry using the specified extractor.

Parameters:

extractor - the extractor to use

entry - the entry to extract from

query

public static Set query(Map map,
                        Filter filter,
                        boolean fEntries,
                        boolean fSort,
                        Comparator comparator)

Generic implementation of the QueryMap API.

Parameters:

map - the underlying Map

filter - the Filter

fEntries - if true, return an entry-set; otherwise a key-set

fSort - if true, sort the entry-set before returning

comparator - the Comparator to use for sorting (optional)