Class PackedHistogram
- java.lang.Object
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- org.HdrHistogram.EncodableHistogram
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- org.HdrHistogram.AbstractHistogramBase
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- org.HdrHistogram.AbstractHistogram
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- org.HdrHistogram.Histogram
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- org.HdrHistogram.PackedHistogram
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- All Implemented Interfaces:
java.io.Serializable
,ValueRecorder
- Direct Known Subclasses:
SingleWriterRecorder.PackedInternalHistogram
public class PackedHistogram extends Histogram
A High Dynamic Range (HDR) Histogram that uses a packed internal representation
PackedHistogram
supports the recording and analyzing sampled data value counts across a configurable integer value range with configurable value precision within the range. Value precision is expressed as the number of significant digits in the value recording, and provides control over value quantization behavior across the value range and the subsequent value resolution at any given level.PackedHistogram
tracks value counts in a packed internal representation optimized for typical histogram recoded values are sparse in the value range and tend to be incremented in small unit counts. This packed representation tends to require significantly smaller amounts of stoarge when compared to unpacked representations, but can incur additional recording cost due to resizing and repacking operations that may occur as previously unrecorded values are encountered.For example, a
PackedHistogram
could be configured to track the counts of observed integer values between 0 and 3,600,000,000,000 while maintaining a value precision of 3 significant digits across that range. Value quantization within the range will thus be no larger than 1/1,000th (or 0.1%) of any value. This example Histogram could be used to track and analyze the counts of observed response times ranging between 1 nanosecond and 1 hour in magnitude, while maintaining a value resolution of 1 microsecond up to 1 millisecond, a resolution of 1 millisecond (or better) up to one second, and a resolution of 1 second (or better) up to 1,000 seconds. At its maximum tracked value (1 hour), it would still maintain a resolution of 3.6 seconds (or better).Auto-resizing: When constructed with no specified value range range (or when auto-resize is turned on with
AbstractHistogram.setAutoResize(boolean)
) aPackedHistogram
will auto-resize its dynamic range to include recorded values as they are encountered. Note that recording calls that cause auto-resizing may take longer to execute, as resizing incurs allocation and copying of internal data structures.See package description for
org.HdrHistogram
for details.- See Also:
- Serialized Form
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Nested Class Summary
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Nested classes/interfaces inherited from class org.HdrHistogram.AbstractHistogram
AbstractHistogram.AllValues, AbstractHistogram.LinearBucketValues, AbstractHistogram.LogarithmicBucketValues, AbstractHistogram.Percentiles, AbstractHistogram.RecordedValues
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Field Summary
Fields Modifier and Type Field Description private PackedLongArray
packedCounts
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Fields inherited from class org.HdrHistogram.Histogram
counts, normalizingIndexOffset, totalCount
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Fields inherited from class org.HdrHistogram.AbstractHistogram
leadingZeroCountBase, maxValue, minNonZeroValue, subBucketHalfCount, subBucketHalfCountMagnitude, subBucketMask, unitMagnitude, unitMagnitudeMask
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Fields inherited from class org.HdrHistogram.AbstractHistogramBase
autoResize, bucketCount, constructionIdentityCount, countsArrayLength, doubleToIntegerValueConversionRatio, endTimeStampMsec, highestTrackableValue, identity, integerToDoubleValueConversionRatio, intermediateUncompressedByteArray, intermediateUncompressedByteBuffer, lowestDiscernibleValue, numberOfSignificantValueDigits, percentileIterator, recordedValuesIterator, startTimeStampMsec, subBucketCount, tag, wordSizeInBytes
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Constructor Summary
Constructors Constructor Description PackedHistogram(int numberOfSignificantValueDigits)
Construct an auto-resizing PackedHistogram with a lowest discernible value of 1 and an auto-adjusting highestTrackableValue.PackedHistogram(long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a PackedHistogram given the Highest value to be tracked and a number of significant decimal digits.PackedHistogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a PackedHistogram given the Lowest and Highest values to be tracked and a number of significant decimal digits.PackedHistogram(AbstractHistogram source)
Construct a PackedHistogram with the same range settings as a given source histogram, duplicating the source's start/end timestamps (but NOT it's contents)
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description (package private) int
_getEstimatedFootprintInBytes()
(package private) void
addToCountAtIndex(int index, long value)
(package private) void
clearCounts()
PackedHistogram
copy()
Create a copy of this histogram, complete with data and everything.PackedHistogram
copyCorrectedForCoordinatedOmission(long expectedIntervalBetweenValueSamples)
Get a copy of this histogram, corrected for coordinated omission.static PackedHistogram
decodeFromByteBuffer(java.nio.ByteBuffer buffer, long minBarForHighestTrackableValue)
Construct a new histogram by decoding it from a ByteBuffer.static PackedHistogram
decodeFromCompressedByteBuffer(java.nio.ByteBuffer buffer, long minBarForHighestTrackableValue)
Construct a new histogram by decoding it from a compressed form in a ByteBuffer.(package private) long
getCountAtIndex(int index)
(package private) long
getCountAtNormalizedIndex(int index)
(package private) void
incrementCountAtIndex(int index)
private void
readObject(java.io.ObjectInputStream o)
(package private) void
resize(long newHighestTrackableValue)
(package private) void
setCountAtIndex(int index, long value)
(package private) void
setCountAtNormalizedIndex(int index, long value)
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Methods inherited from class org.HdrHistogram.Histogram
addToTotalCount, fromString, getNormalizingIndexOffset, getTotalCount, incrementTotalCount, setIntegerToDoubleValueConversionRatio, setNormalizingIndexOffset, setTotalCount, shiftNormalizingIndexByOffset
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Methods inherited from class org.HdrHistogram.AbstractHistogram
add, addWhileCorrectingForCoordinatedOmission, allValues, copyInto, copyIntoCorrectedForCoordinatedOmission, countsArrayIndex, decodeFromByteBuffer, decodeFromCompressedByteBuffer, determineArrayLengthNeeded, encodeIntoByteBuffer, encodeIntoCompressedByteBuffer, encodeIntoCompressedByteBuffer, equals, establishInternalTackingValues, establishInternalTackingValues, establishSize, fillBufferFromCountsArray, getBucketIndex, getBucketsNeededToCoverValue, getCountAtValue, getCountBetweenValues, getEndTimeStamp, getEstimatedFootprintInBytes, getHighestTrackableValue, getLengthForNumberOfBuckets, getLowestDiscernibleValue, getMaxValue, getMaxValueAsDouble, getMean, getMinNonZeroValue, getMinValue, getNeededByteBufferCapacity, getNeededByteBufferCapacity, getNeededPayloadByteBufferCapacity, getNeededV0PayloadByteBufferCapacity, getNumberOfSignificantValueDigits, getPercentileAtOrBelowValue, getStartTimeStamp, getStdDeviation, getSubBucketIndex, getTag, getValueAtPercentile, hashCode, highestEquivalentValue, isAutoResize, linearBucketValues, logarithmicBucketValues, lowestEquivalentValue, medianEquivalentValue, nextNonEquivalentValue, nonConcurrentNormalizingIndexShift, normalizeIndex, numberOfSubbuckets, outputPercentileDistribution, outputPercentileDistribution, outputPercentileDistribution, percentiles, recordConvertedDoubleValue, recordConvertedDoubleValueWithCount, recordedValues, recordValue, recordValue, recordValueWithCount, recordValueWithExpectedInterval, reset, setAutoResize, setEndTimeStamp, setStartTimeStamp, setTag, shiftValuesLeft, shiftValuesLeft, shiftValuesRight, shiftValuesRight, sizeOfEquivalentValueRange, subtract, supportsAutoResize, toString, updateMinAndMax, valueFromIndex, valuesAreEquivalent
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Methods inherited from class org.HdrHistogram.AbstractHistogramBase
getDoubleToIntegerValueConversionRatio, getIntegerToDoubleValueConversionRatio, nonConcurrentSetIntegerToDoubleValueConversionRatio
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Field Detail
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packedCounts
private PackedLongArray packedCounts
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Constructor Detail
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PackedHistogram
public PackedHistogram(int numberOfSignificantValueDigits)
Construct an auto-resizing PackedHistogram with a lowest discernible value of 1 and an auto-adjusting highestTrackableValue. Can auto-resize up to track values up to (Long.MAX_VALUE / 2).- Parameters:
numberOfSignificantValueDigits
- Specifies the precision to use. This is the number of significant decimal digits to which the histogram will maintain value resolution and separation. Must be a non-negative integer between 0 and 5.
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PackedHistogram
public PackedHistogram(long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a PackedHistogram given the Highest value to be tracked and a number of significant decimal digits. The histogram will be constructed to implicitly track (distinguish from 0) values as low as 1.- Parameters:
highestTrackableValue
- The highest value to be tracked by the histogram. Must be a positive integer that is >= 2.numberOfSignificantValueDigits
- Specifies the precision to use. This is the number of significant decimal digits to which the histogram will maintain value resolution and separation. Must be a non-negative integer between 0 and 5.
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PackedHistogram
public PackedHistogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a PackedHistogram given the Lowest and Highest values to be tracked and a number of significant decimal digits. Providing a lowestDiscernibleValue is useful is situations where the units used for the histogram's values are much smaller that the minimal accuracy required. E.g. when tracking time values stated in nanosecond units, where the minimal accuracy required is a microsecond, the proper value for lowestDiscernibleValue would be 1000.- Parameters:
lowestDiscernibleValue
- The lowest value that can be tracked (distinguished from 0) by the histogram. Must be a positive integer that is >= 1. May be internally rounded down to nearest power of 2.highestTrackableValue
- The highest value to be tracked by the histogram. Must be a positive integer that is >= (2 * lowestDiscernibleValue).numberOfSignificantValueDigits
- Specifies the precision to use. This is the number of significant decimal digits to which the histogram will maintain value resolution and separation. Must be a non-negative integer between 0 and 5.
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PackedHistogram
public PackedHistogram(AbstractHistogram source)
Construct a PackedHistogram with the same range settings as a given source histogram, duplicating the source's start/end timestamps (but NOT it's contents)- Parameters:
source
- The source histogram to duplicate
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Method Detail
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getCountAtIndex
long getCountAtIndex(int index)
- Overrides:
getCountAtIndex
in classHistogram
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getCountAtNormalizedIndex
long getCountAtNormalizedIndex(int index)
- Overrides:
getCountAtNormalizedIndex
in classHistogram
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incrementCountAtIndex
void incrementCountAtIndex(int index)
- Overrides:
incrementCountAtIndex
in classHistogram
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addToCountAtIndex
void addToCountAtIndex(int index, long value)
- Overrides:
addToCountAtIndex
in classHistogram
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setCountAtIndex
void setCountAtIndex(int index, long value)
- Overrides:
setCountAtIndex
in classHistogram
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setCountAtNormalizedIndex
void setCountAtNormalizedIndex(int index, long value)
- Overrides:
setCountAtNormalizedIndex
in classHistogram
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clearCounts
void clearCounts()
- Overrides:
clearCounts
in classHistogram
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copy
public PackedHistogram copy()
Description copied from class:AbstractHistogram
Create a copy of this histogram, complete with data and everything.
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copyCorrectedForCoordinatedOmission
public PackedHistogram copyCorrectedForCoordinatedOmission(long expectedIntervalBetweenValueSamples)
Description copied from class:AbstractHistogram
Get a copy of this histogram, corrected for coordinated omission.To compensate for the loss of sampled values when a recorded value is larger than the expected interval between value samples, the new histogram will include an auto-generated additional series of decreasingly-smaller (down to the expectedIntervalBetweenValueSamples) value records for each count found in the current histogram that is larger than the expectedIntervalBetweenValueSamples. Note: This is a post-correction method, as opposed to the at-recording correction method provided by
recordValueWithExpectedInterval
. The two methods are mutually exclusive, and only one of the two should be be used on a given data set to correct for the same coordinated omission issue. bySee notes in the description of the Histogram calls for an illustration of why this corrective behavior is important.
- Overrides:
copyCorrectedForCoordinatedOmission
in classHistogram
- Parameters:
expectedIntervalBetweenValueSamples
- If expectedIntervalBetweenValueSamples is larger than 0, add auto-generated value records as appropriate if value is larger than expectedIntervalBetweenValueSamples- Returns:
- a copy of this histogram, corrected for coordinated omission.
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_getEstimatedFootprintInBytes
int _getEstimatedFootprintInBytes()
- Overrides:
_getEstimatedFootprintInBytes
in classHistogram
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decodeFromByteBuffer
public static PackedHistogram decodeFromByteBuffer(java.nio.ByteBuffer buffer, long minBarForHighestTrackableValue)
Construct a new histogram by decoding it from a ByteBuffer.- Parameters:
buffer
- The buffer to decode fromminBarForHighestTrackableValue
- Force highestTrackableValue to be set at least this high- Returns:
- The newly constructed histogram
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decodeFromCompressedByteBuffer
public static PackedHistogram decodeFromCompressedByteBuffer(java.nio.ByteBuffer buffer, long minBarForHighestTrackableValue) throws java.util.zip.DataFormatException
Construct a new histogram by decoding it from a compressed form in a ByteBuffer.- Parameters:
buffer
- The buffer to decode fromminBarForHighestTrackableValue
- Force highestTrackableValue to be set at least this high- Returns:
- The newly constructed histogram
- Throws:
java.util.zip.DataFormatException
- on error parsing/decompressing the buffer
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readObject
private void readObject(java.io.ObjectInputStream o) throws java.io.IOException, java.lang.ClassNotFoundException
- Throws:
java.io.IOException
java.lang.ClassNotFoundException
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