Package com.tangosol.util.aggregator

Class DoubleAverage<T>

java.lang.Object

com.tangosol.util.Base

com.tangosol.util.BitHelper

com.tangosol.util.ExternalizableHelper

com.tangosol.util.aggregator.AbstractAggregator<Object,Object,T,Number,Double>

com.tangosol.util.aggregator.AbstractDoubleAggregator<T>

com.tangosol.util.aggregator.DoubleAverage<T>

Type Parameters:

T - the type of the value to extract from

All Implemented Interfaces:

ExternalizableLite, PortableObject, InvocableMap.EntryAggregator<Object,Object,Double>, InvocableMap.StreamingAggregator<Object,Object,Object,Double>, Serializable, Cloneable

public class DoubleAverage<T>
extends AbstractDoubleAggregator<T>

Calculates an average for values of any numeric type extracted from a set of entries in a Map. All the extracted Number objects will be treated as Java double values. If the set of entries is empty, a null result is returned.

Since:

Coherence 3.1

Author:

gg 2005.09.05

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.tangosol.util.ExternalizableHelper

ExternalizableHelper.DecoratedMultiBufferReadBuffer, ExternalizableHelper.DefaultObjectStreamFactory, ExternalizableHelper.FormatAwareCompressor, ExternalizableHelper.IntDecoratedObject, ExternalizableHelper.Shielded, ExternalizableHelper.ShieldedDataOutputStream, ExternalizableHelper.ShieldedInputStream, ExternalizableHelper.ShieldedObjectOutputStream, ExternalizableHelper.ShieldedOutputStream, ExternalizableHelper.SimpleXmlBeanClassCache, ExternalizableHelper.Stats, ExternalizableHelper.XmlBeanClassCache

Nested classes/interfaces inherited from class com.tangosol.util.Base

Base.LoggingWriter

Field Summary

Fields inherited from class com.tangosol.util.aggregator.AbstractDoubleAggregator

m_count, m_dflResult

Fields inherited from class com.tangosol.util.aggregator.AbstractAggregator

m_fParallel

Fields inherited from class com.tangosol.util.ExternalizableHelper

BINARY_SIZE, CHUNK_SIZE, CHUNK_THRESHOLD, CONVERTER_FROM_BINARY, CONVERTER_STRIP_INTDECO, CONVERTER_TO_BINARY, DECO_APP_1, DECO_APP_2, DECO_APP_3, DECO_BACKUP, DECO_CUSTOM, DECO_EXPIRY, DECO_ID_MAX, DECO_ID_MIN, DECO_JCACHE, DECO_JCACHE_SYNTHETIC, DECO_MEMCACHED, DECO_PUSHREP, DECO_QUEUE_METADATA, DECO_RSVD_1, DECO_STORE, DECO_TX, DECO_VALUE, DECO_WLS, EMPTY_BINARY_ARRAY, FMT_B_ARRAY, FMT_BIN_DECO, FMT_BIN_EXT_DECO, FMT_BINARY, FMT_BOOLEAN, FMT_BYTE, FMT_DECIMAL, FMT_DOUBLE, FMT_EXT, FMT_FLOAT, FMT_IDO, FMT_INT, FMT_INTEGER, FMT_LONG, FMT_NONE, FMT_NULL, FMT_OBJ_EXT, FMT_OBJ_SER, FMT_OPT, FMT_OPT_DOUBLE, FMT_OPT_INT, FMT_OPT_LONG, FMT_SHORT, FMT_STRING, FMT_UNKNOWN, FMT_XML_BEAN, FMT_XML_SER, FORCE_RESOLVING_STREAMS, LAMBDA_SERIALIZATION, MAX_DECO_HEADER_BYTES, PACKED_INT_SIZE, PACKED_LONG_SIZE, PROPERTY_CONFIG, s_streamfactory, TRINT_DOMAIN_SPAN, TRINT_MAX_VALUE, TRINT_MAX_VARIANCE, USE_POF_STREAMS, USE_XMLBEAN_CLASS_CACHE, XMLBEAN_CLASS_CACHE

Fields inherited from class com.tangosol.util.Base

LOG_ALWAYS, LOG_CONFIG, LOG_DEBUG, LOG_ERR, LOG_INFO, LOG_MAX, LOG_MIN, LOG_QUIET, LOG_WARN, POWER_0, POWER_G, POWER_K, POWER_M, POWER_T, UNIT_D, UNIT_H, UNIT_M, UNIT_MS, UNIT_NS, UNIT_S, UNIT_US

Fields inherited from interface com.tangosol.util.InvocableMap.StreamingAggregator

ALLOW_INCONSISTENCIES, BY_MEMBER, BY_PARTITION, PARALLEL, PRESENT_ONLY, RETAINS_ENTRIES, SERIAL

Constructor Summary

Constructors

Constructor	Description
DoubleAverage()	Default constructor (necessary for the ExternalizableLite interface).
DoubleAverage(ValueExtractor<? super T,? extends Number> extractor)	Construct a DoubleAverage aggregator.
DoubleAverage(String sMethod)	Construct an DoubleAverage object.

Method Summary

Modifier and Type	Method	Description
int	characteristics()	A bit mask representing the set of characteristics of this aggregator.
protected Object	finalizeResult(boolean fFinal)	Obtain the result of the aggregation.
protected void	init(boolean fFinal)	Initialize the aggregation result.
protected void	process(Object o, boolean fFinal)	Incorporate one aggregatable value into the result.
InvocableMap.StreamingAggregator<Object,Object,Object,Double>	supply()	Create a new instance of this aggregator.

Methods inherited from class com.tangosol.util.aggregator.AbstractAggregator

accumulate, accumulate, combine, ensureInitialized, equals, finalizeResult, getPartialResult, getValueExtractor, hashCode, processEntry, readExternal, readExternal, toString, writeExternal, writeExternal

Methods inherited from class com.tangosol.util.ExternalizableHelper

asBinary, calculatePackedLength, calculatePackedLength, checkObjectInputFilter, checkObjectInputFilter, checkObjectInputFilter, convertUTF, decodeExpiry, decorate, decorate, decorate, decorate, decorate, decorateBinary, encodeExpiry, ensureSerializer, extractIntDecoration, fromBinary, fromBinary, fromBinary, fromBinary, fromBinary, fromBinary, fromByteArray, fromByteArray, getClass, getConfigSerialFilter, getConfigSerialFilterFactory, getDecoration, getDecoration, getDecorations, getDeltaCompressor, getInputStream, getNewObjectInput, getObjectInput, getObjectInputFilter, getObjectOutput, getObjectStreamFactory, getOutputStream, getShieldedOutputStream, getStreamFormat, getUndecorated, getUndecorated, isDecorated, isDecorated, isIntDecorated, isIntDecorated, isResolving, isSerializable, isSerializerCompatible, isVersionCompatible, isVersionCompatible, isVersionCompatible, isVersionCompatible, loadClass, loadResource, main, makeTrint, readBigDecimal, readBigInteger, readBooleanArray, readBooleanArray, readByteArray, readCharArray, readCharArray, readCollection, readDate, readDoubleArray, readDoubleArray, readExternalizableLite, readExternalizableLite, readFloatArray, readFloatArray, readInt, readInt, readIntArray, readIntArray, readIntArray2d, readLargeBooleanArray, readLargeByteArray, readLargeCharArray, readLargeDoubleArray, readLargeFloatArray, readLargeIntArray, readLargeLongArray, readLargeObjectArray, readLargeStringArray, readLong, readLong, readLongArray, readLongArray, readMap, readMap, readObject, readObject, readObjectArray, readObjectArray, readSafeUTF, readSafeUTF, readSerializable, readSerializable, readStringArray, readStringArray, readTime, readTimestamp, readTrint, readUnsignedTrint, readUTF, readXmlBean, readXmlSerializable, readXmlSerializable, realize, removeIntDecoration, removeIntDecoration, replace, reportIncompatibleSerializers, setObjectStreamFactory, toBinary, toBinary, toBinary, toByteArray, toByteArray, toByteArray, toLiteBinary, toLong, undecorate, undecorate, validateBufferSize, validateLoadArray, validateLoadClass, writeBigDecimal, writeBigInteger, writeBooleanArray, writeByteArray, writeCollection, writeDate, writeDoubleArray, writeExternalizableLite, writeFloatArray, writeInt, writeInt, writeIntArray2d, writeLong, writeLong, writeMap, writeObject, writeSafeUTF, writeSafeUTF, writeSerializable, writeStringArray, writeTime, writeTimestamp, writeTrint, writeTrint, writeUTF, writeXmlBean, writeXmlSerializable

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, toBytes, toBytes, toBytes, toBytes, toInt, toInt, toLong

Methods inherited from class com.tangosol.util.Base

azzert, azzert, azzert, azzertFailed, breakLines, breakLines, capitalize, checkNotEmpty, checkNotNull, checkRange, computeSafeWaitTime, decimalValue, dup, dup, ensureBigDecimal, ensureClassLoader, ensureRuntimeException, ensureRuntimeException, equals, equalsDeep, err, err, err, err, err, escape, formatDateTime, getCallerStackFrame, getCommonMonitor, getCommonMonitor, getCommonMonitor, getContextClassLoader, getContextClassLoader, getDeepMessage, getErr, getLastSafeTimeMillis, getLog, getMaxDecDigits, getMaxHexDigits, getOriginalException, getOut, getProcessRandom, getRandom, getRandomBinary, getRandomBinary, getRandomString, getSafeTimeMillis, getStackFrame, getStackFrames, getStackTrace, getStackTrace, getStackTrace, getThreadFactory, getTimeZone, getUpTimeMillis, hashCode, hexValue, indentString, indentString, isDecimal, isHex, isLogEcho, isOctal, log, log, log, log, log, makeInteger, makeLong, makeThread, mergeArray, mergeBooleanArray, mergeByteArray, mergeCharArray, mergeDoubleArray, mergeFloatArray, mergeIntArray, mergeLongArray, mod, mod, octalValue, out, out, out, out, out, pad, parseBandwidth, parseBandwidth, parseDelimitedString, parseHex, parseHex, parseMemorySize, parseMemorySize, parsePercentage, parseTime, parseTime, parseTimeNanos, parseTimeNanos, printStackTrace, randomize, randomize, randomize, randomize, read, read, read, read, read, read, read, replace, setErr, setLog, setLogEcho, setOut, sleep, toBandwidthString, toBandwidthString, toCharEscape, toCrc, toCrc, toCrc, toCrc, toCrc, toDecString, toDelimitedString, toDelimitedString, toDelimitedString, toDelimitedString, toHex, toHex, toHexDump, toHexEscape, toHexEscape, toHexEscape, toHexEscape, toHexString, toMemorySizeString, toMemorySizeString, toQuotedCharEscape, toQuotedStringEscape, toSqlString, toString, toString, toStringEscape, toUnicodeEscape, trace, trace, trace, trace, trace, trace, trace, trace, trace, truncateString, truncateString, wait

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.tangosol.util.InvocableMap.StreamingAggregator

aggregate, isAllowInconsistencies, isByMember, isByPartition, isParallel, isPresentOnly, isRetainsEntries, isSerial

Constructor Details

DoubleAverage

public DoubleAverage()

Default constructor (necessary for the ExternalizableLite interface).

DoubleAverage

public DoubleAverage(ValueExtractor<? super T,? extends Number> extractor)

Construct a DoubleAverage aggregator.

Parameters:

extractor - the extractor that provides a value in the form of any Java object that is a Number

DoubleAverage

public DoubleAverage(String sMethod)

Construct an DoubleAverage object.

Parameters:

sMethod - the name of the method that returns a value in the form of any Java object that is a Number

Method Details

supply

public InvocableMap.StreamingAggregator<Object,Object,Object,Double> supply()

Description copied from interface: InvocableMap.StreamingAggregator

Create a new instance of this aggregator.

Specified by:

supply in interface InvocableMap.StreamingAggregator<Object,Object,Object,Double>

Overrides:

supply in class AbstractAggregator<Object,Object,T,Number,Double>

Returns:

a StreamAggregator

characteristics

public int characteristics()

Description copied from interface: InvocableMap.StreamingAggregator

A bit mask representing the set of characteristics of this aggregator.

By default, characteristics are a combination of InvocableMap.StreamingAggregator.PARALLEL and InvocableMap.StreamingAggregator.RETAINS_ENTRIES, which is sub-optimal and should be overridden by the aggregator implementation if the aggregator does not need to retain entries (which is often the case).

Returns:

a bit mask representing the set of characteristics of this aggregator

See Also:

• InvocableMap.StreamingAggregator.ALLOW_INCONSISTENCIES
• InvocableMap.StreamingAggregator.BY_MEMBER
• InvocableMap.StreamingAggregator.BY_PARTITION
• InvocableMap.StreamingAggregator.PARALLEL
• InvocableMap.StreamingAggregator.PRESENT_ONLY
• InvocableMap.StreamingAggregator.RETAINS_ENTRIES
• InvocableMap.StreamingAggregator.SERIAL

init

protected void init(boolean fFinal)

Initialize the aggregation result.

Overrides:

init in class AbstractDoubleAggregator<T>

Parameters:

fFinal - true is passed if the aggregation process that is being initialized must produce a final aggregation result; this will only be false if a parallel approach is being used and the initial (partial) aggregation process is being initialized

process

protected void process(Object o,
 boolean fFinal)

Incorporate one aggregatable value into the result.

If the fFinal parameter is true, the given object is a partial result (returned by an individual parallel aggregator) that should be incorporated into the final result; otherwise, the object is a value extracted from an InvocableMap.Entry.

Specified by:

process in class AbstractAggregator<Object,Object,T,Number,Double>

Parameters:

o - the value to incorporate into the aggregated result

fFinal - true to indicate that the given object is a partial result returned by a parallel aggregator

finalizeResult

protected Object finalizeResult(boolean fFinal)

Obtain the result of the aggregation.

If the fFinal parameter is true, the returned object must be the final result of the aggregation; otherwise, the returned object will be treated as a partial result that should be incorporated into the final result.

Overrides:

finalizeResult in class AbstractDoubleAggregator<T>

Parameters:

fFinal - true to indicate that the final result of the aggregation process should be returned; this will only be false if a parallel approach is being used

Returns:

the result of the aggregation process