Class Histogram
- 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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- All Implemented Interfaces:
java.io.Serializable
,ValueRecorder
- Direct Known Subclasses:
AtomicHistogram
,ConcurrentHistogram
,PackedHistogram
,SingleWriterRecorder.InternalHistogram
,SynchronizedHistogram
public class Histogram extends AbstractHistogram
A High Dynamic Range (HDR) Histogram
Histogram
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.For example, a Histogram could be configured to track the counts of observed integer values between 0 and 3,600,000,000 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 microsecond 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).
Histogram tracks value counts in
long
fields. Smaller field types are available in theIntCountsHistogram
andShortCountsHistogram
implementations ofAbstractHistogram
.Auto-resizing: When constructed with no specified value range range (or when auto-resize is turned on with
AbstractHistogram.setAutoResize(boolean)
) aHistogram
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 (package private) long[]
counts
(package private) int
normalizingIndexOffset
(package private) long
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 Histogram(int numberOfSignificantValueDigits)
Construct an auto-resizing histogram with a lowest discernible value of 1 and an auto-adjusting highestTrackableValue.Histogram(long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a Histogram given the Highest value to be tracked and a number of significant decimal digits.Histogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a Histogram given the Lowest and Highest values to be tracked and a number of significant decimal digits.Histogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits, boolean allocateCountsArray)
Histogram(AbstractHistogram source)
Construct a histogram with the same range settings as a given source histogram, duplicating the source's start/end timestamps (but NOT its contents)Histogram(AbstractHistogram source, boolean allocateCountsArray)
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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
addToTotalCount(long value)
(package private) void
clearCounts()
Histogram
copy()
Create a copy of this histogram, complete with data and everything.Histogram
copyCorrectedForCoordinatedOmission(long expectedIntervalBetweenValueSamples)
Get a copy of this histogram, corrected for coordinated omission.static Histogram
decodeFromByteBuffer(java.nio.ByteBuffer buffer, long minBarForHighestTrackableValue)
Construct a new histogram by decoding it from a ByteBuffer.static Histogram
decodeFromCompressedByteBuffer(java.nio.ByteBuffer buffer, long minBarForHighestTrackableValue)
Construct a new histogram by decoding it from a compressed form in a ByteBuffer.static Histogram
fromString(java.lang.String base64CompressedHistogramString)
Construct a new Histogram by decoding it from a String containing a base64 encoded compressed histogram representation.(package private) long
getCountAtIndex(int index)
(package private) long
getCountAtNormalizedIndex(int index)
(package private) int
getNormalizingIndexOffset()
long
getTotalCount()
Get the total count of all recorded values in the histogram(package private) void
incrementCountAtIndex(int index)
(package private) void
incrementTotalCount()
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)
(package private) void
setIntegerToDoubleValueConversionRatio(double integerToDoubleValueConversionRatio)
(package private) void
setNormalizingIndexOffset(int normalizingIndexOffset)
(package private) void
setTotalCount(long totalCount)
(package private) void
shiftNormalizingIndexByOffset(int offsetToAdd, boolean lowestHalfBucketPopulated, double newIntegerToDoubleValueConversionRatio)
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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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Constructor Detail
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Histogram
public Histogram(int numberOfSignificantValueDigits)
Construct an auto-resizing histogram 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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Histogram
public Histogram(long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a Histogram 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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Histogram
public Histogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a Histogram 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 discerned (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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Histogram
public Histogram(AbstractHistogram source)
Construct a histogram with the same range settings as a given source histogram, duplicating the source's start/end timestamps (but NOT its contents)- Parameters:
source
- The source histogram to duplicate
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Histogram
Histogram(AbstractHistogram source, boolean allocateCountsArray)
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Histogram
Histogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits, boolean allocateCountsArray)
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Method Detail
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getCountAtIndex
long getCountAtIndex(int index)
- Specified by:
getCountAtIndex
in classAbstractHistogram
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getCountAtNormalizedIndex
long getCountAtNormalizedIndex(int index)
- Specified by:
getCountAtNormalizedIndex
in classAbstractHistogram
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incrementCountAtIndex
void incrementCountAtIndex(int index)
- Specified by:
incrementCountAtIndex
in classAbstractHistogram
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addToCountAtIndex
void addToCountAtIndex(int index, long value)
- Specified by:
addToCountAtIndex
in classAbstractHistogram
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setCountAtIndex
void setCountAtIndex(int index, long value)
- Specified by:
setCountAtIndex
in classAbstractHistogram
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setCountAtNormalizedIndex
void setCountAtNormalizedIndex(int index, long value)
- Specified by:
setCountAtNormalizedIndex
in classAbstractHistogram
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getNormalizingIndexOffset
int getNormalizingIndexOffset()
- Specified by:
getNormalizingIndexOffset
in classAbstractHistogram
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setNormalizingIndexOffset
void setNormalizingIndexOffset(int normalizingIndexOffset)
- Specified by:
setNormalizingIndexOffset
in classAbstractHistogram
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setIntegerToDoubleValueConversionRatio
void setIntegerToDoubleValueConversionRatio(double integerToDoubleValueConversionRatio)
- Specified by:
setIntegerToDoubleValueConversionRatio
in classAbstractHistogramBase
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shiftNormalizingIndexByOffset
void shiftNormalizingIndexByOffset(int offsetToAdd, boolean lowestHalfBucketPopulated, double newIntegerToDoubleValueConversionRatio)
- Specified by:
shiftNormalizingIndexByOffset
in classAbstractHistogram
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clearCounts
void clearCounts()
- Specified by:
clearCounts
in classAbstractHistogram
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copy
public Histogram copy()
Description copied from class:AbstractHistogram
Create a copy of this histogram, complete with data and everything.- Specified by:
copy
in classAbstractHistogram
- Returns:
- A distinct copy of this histogram.
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copyCorrectedForCoordinatedOmission
public Histogram 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.
- Specified by:
copyCorrectedForCoordinatedOmission
in classAbstractHistogram
- 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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getTotalCount
public long getTotalCount()
Description copied from class:AbstractHistogram
Get the total count of all recorded values in the histogram- Specified by:
getTotalCount
in classAbstractHistogram
- Returns:
- the total count of all recorded values in the histogram
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setTotalCount
void setTotalCount(long totalCount)
- Specified by:
setTotalCount
in classAbstractHistogram
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incrementTotalCount
void incrementTotalCount()
- Specified by:
incrementTotalCount
in classAbstractHistogram
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addToTotalCount
void addToTotalCount(long value)
- Specified by:
addToTotalCount
in classAbstractHistogram
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_getEstimatedFootprintInBytes
int _getEstimatedFootprintInBytes()
- Specified by:
_getEstimatedFootprintInBytes
in classAbstractHistogram
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resize
void resize(long newHighestTrackableValue)
- Specified by:
resize
in classAbstractHistogram
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decodeFromByteBuffer
public static Histogram 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 Histogram 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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fromString
public static Histogram fromString(java.lang.String base64CompressedHistogramString) throws java.util.zip.DataFormatException
Construct a new Histogram by decoding it from a String containing a base64 encoded compressed histogram representation.- Parameters:
base64CompressedHistogramString
- A string containing a base64 encoding of a compressed histogram- Returns:
- A Histogream decoded from the string
- Throws:
java.util.zip.DataFormatException
- on error parsing/decompressing the input
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