public class Count<K,V> extends Base implements InvocableMap.StreamingAggregator<K,V,Integer,Integer>, ExternalizableLite, PortableObject
Base.LoggingWriter, Base.StackFrame
LOG_ALWAYS, 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
BY_MEMBER, BY_PARTITION, PARALLEL, PRESENT_ONLY, RETAINS_ENTRIES, SERIAL
Constructor and Description |
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Count()
Default constructor (necessary for the ExternalizableLite interface).
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Modifier and Type | Method and Description |
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boolean |
accumulate(InvocableMap.Entry<? extends K,? extends V> entry)
Accumulate one entry into the result.
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boolean |
accumulate(Streamer<? extends InvocableMap.Entry<? extends K,? extends V>> streamer)
Accumulate multiple entries into the result.
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int |
characteristics()
A bit mask representing the set of characteristics of this aggregator.
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boolean |
combine(Integer partialResult)
Merge another partial result into the result.
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Integer |
finalizeResult()
Return the final result of the aggregation.
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Integer |
getPartialResult()
Return the partial result of the aggregation.
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void |
readExternal(DataInput in)
Restore the contents of this object by loading the object's state from the passed DataInput object.
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void |
readExternal(PofReader in)
Restore the contents of a user type instance by reading its state using the specified PofReader object.
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InvocableMap.StreamingAggregator<K,V,Integer,Integer> |
supply()
Create a new instance of this aggregator.
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void |
writeExternal(DataOutput out)
Save the contents of this object by storing the object's state into the passed DataOutput object.
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void |
writeExternal(PofWriter out)
Save the contents of a POF user type instance by writing its state using the specified PofWriter object.
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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, getRandom, getRandomBinary, getRandomBinary, getRandomString, getSafeTimeMillis, getStackFrame, getStackFrames, getStackTrace, getStackTrace, getThreadFactory, getTimeZone, getUpTimeMillis, hashCode, hexValue, indentString, indentString, isDecimal, isHex, isLogEcho, isOctal, log, log, log, log, log, makeInteger, makeLong, makeThread, 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, 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
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
aggregate, isByMember, isByPartition, isParallel, isPresentOnly, isRetainsEntries, isSerial
public Count()
public InvocableMap.StreamingAggregator<K,V,Integer,Integer> supply()
InvocableMap.StreamingAggregator
public boolean accumulate(Streamer<? extends InvocableMap.Entry<? extends K,? extends V>> streamer)
InvocableMap.StreamingAggregator
Important note: The default implementation of this method provides necessary logic for aggregation short-circuiting and should rarely (if ever) be overridden by the custom aggregator implementation.
accumulate
in interface InvocableMap.StreamingAggregator<K,V,Integer,Integer>
streamer
- a Streamer
that can be used to iterate over entries to addpublic boolean accumulate(InvocableMap.Entry<? extends K,? extends V> entry)
InvocableMap.StreamingAggregator
accumulate
in interface InvocableMap.StreamingAggregator<K,V,Integer,Integer>
entry
- the entry to accumulate into the aggregation resultpublic boolean combine(Integer partialResult)
InvocableMap.StreamingAggregator
combine
in interface InvocableMap.StreamingAggregator<K,V,Integer,Integer>
partialResult
- the partial result to mergepublic Integer getPartialResult()
InvocableMap.StreamingAggregator
getPartialResult
in interface InvocableMap.StreamingAggregator<K,V,Integer,Integer>
public Integer finalizeResult()
InvocableMap.StreamingAggregator
finalizeResult
in interface InvocableMap.StreamingAggregator<K,V,Integer,Integer>
public int characteristics()
InvocableMap.StreamingAggregator
Be 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).
characteristics
in interface InvocableMap.StreamingAggregator<K,V,Integer,Integer>
InvocableMap.StreamingAggregator.PARALLEL
, InvocableMap.StreamingAggregator.SERIAL
, InvocableMap.StreamingAggregator.BY_MEMBER
, InvocableMap.StreamingAggregator.BY_PARTITION
, InvocableMap.StreamingAggregator.RETAINS_ENTRIES
, InvocableMap.StreamingAggregator.PRESENT_ONLY
public void readExternal(DataInput in) throws IOException
readExternal
in interface ExternalizableLite
in
- the DataInput stream to read data from in order to restore the state of this objectIOException
- if an I/O exception occursNotActiveException
- if the object is not in its initial state, and therefore cannot be deserialized intopublic void writeExternal(DataOutput out) throws IOException
writeExternal
in interface ExternalizableLite
out
- the DataOutput stream to write the state of this object toIOException
- if an I/O exception occurspublic void readExternal(PofReader in) throws IOException
readExternal
in interface PortableObject
in
- the PofReader from which to read the object's stateIOException
- if an I/O error occurspublic void writeExternal(PofWriter out) throws IOException
writeExternal
in interface PortableObject
out
- the PofWriter to which to write the object's stateIOException
- if an I/O error occurs