Class ConcurrentHistogram
- 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.ConcurrentHistogram
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- All Implemented Interfaces:
java.io.Serializable
,ValueRecorder
- Direct Known Subclasses:
PackedConcurrentHistogram
,Recorder.InternalConcurrentHistogram
public class ConcurrentHistogram extends Histogram
An integer values High Dynamic Range (HDR) Histogram that supports safe concurrent recording operations.
A ConcurrentHistogram guarantees lossless recording of values into the histogram even when the histogram is updated by multiple threads, and supports auto-resize and shift operations that may result from or occur concurrently with other recording operations.It is important to note that concurrent recording, auto-sizing, and value shifting are the only thread-safe behaviors provided by
ConcurrentHistogram
, and that it is not otherwise synchronized. Specifically,ConcurrentHistogram
provides no implicit synchronization that would prevent the contents of the histogram from changing during queries, iterations, copies, or addition operations on the histogram. Callers wishing to make potentially concurrent, multi-threaded updates that would safely work in the presence of queries, copies, or additions of histogram objects should either take care to externally synchronize and/or order their access, use theSynchronizedHistogram
variant, or (recommended) useRecorder
orSingleWriterRecorder
which are intended for this purpose.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
Nested Classes Modifier and Type Class Description (package private) static class
ConcurrentHistogram.AtomicLongArrayWithNormalizingOffset
(package private) static interface
ConcurrentHistogram.ConcurrentArrayWithNormalizingOffset
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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) ConcurrentHistogram.ConcurrentArrayWithNormalizingOffset
activeCounts
(package private) ConcurrentHistogram.ConcurrentArrayWithNormalizingOffset
inactiveCounts
(package private) long
totalCount
(package private) static java.util.concurrent.atomic.AtomicLongFieldUpdater<ConcurrentHistogram>
totalCountUpdater
(package private) WriterReaderPhaser
wrp
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Fields inherited from class org.HdrHistogram.Histogram
counts, normalizingIndexOffset
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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 ConcurrentHistogram(int numberOfSignificantValueDigits)
Construct an auto-resizing ConcurrentHistogram with a lowest discernible value of 1 and an auto-adjusting highestTrackableValue.ConcurrentHistogram(long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a ConcurrentHistogram given the Highest value to be tracked and a number of significant decimal digits.ConcurrentHistogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a ConcurrentHistogram given the Lowest and Highest values to be tracked and a number of significant decimal digits.ConcurrentHistogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits, boolean allocateCountsArray)
ConcurrentHistogram(AbstractHistogram source)
Construct a histogram with the same range settings as a given source histogram, duplicating the source's start/end timestamps (but NOT it's contents)ConcurrentHistogram(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) ConcurrentHistogram.ConcurrentArrayWithNormalizingOffset
allocateArray(int length, int normalizingIndexOffset)
(package private) void
clearCounts()
ConcurrentHistogram
copy()
Create a copy of this histogram, complete with data and everything.ConcurrentHistogram
copyCorrectedForCoordinatedOmission(long expectedIntervalBetweenValueSamples)
Get a copy of this histogram, corrected for coordinated omission.(package private) void
copyInactiveCountsContentsOnResize(ConcurrentHistogram.ConcurrentArrayWithNormalizingOffset oldInactiveCounts, int countsDelta)
static ConcurrentHistogram
decodeFromByteBuffer(java.nio.ByteBuffer buffer, long minBarForHighestTrackableValue)
Construct a new histogram by decoding it from a ByteBuffer.static ConcurrentHistogram
decodeFromCompressedByteBuffer(java.nio.ByteBuffer buffer, long minBarForHighestTrackableValue)
Construct a new histogram by decoding it from a compressed form in a ByteBuffer.(package private) void
fillBufferFromCountsArray(java.nio.ByteBuffer buffer)
static ConcurrentHistogram
fromString(java.lang.String base64CompressedHistogramString)
Construct a new ConcurrentHistogram 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
recordConvertedDoubleValue(double value)
void
recordConvertedDoubleValueWithCount(double value, long count)
(package private) void
resize(long newHighestTrackableValue)
void
setAutoResize(boolean autoResize)
Control whether or not the histogram can auto-resize and auto-adjust it's highestTrackableValue(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)
private void
setNormalizingIndexOffset(int newNormalizingIndexOffset, int shiftedAmount, boolean lowestHalfBucketPopulated, double newIntegerToDoubleValueConversionRatio)
private void
setNormalizingIndexOffsetForInactive(int newNormalizingIndexOffset, int shiftedAmount, boolean lowestHalfBucketPopulated, double newIntegerToDoubleValueConversionRatio)
(package private) void
setTotalCount(long totalCount)
private void
shiftLowestInactiveHalfBucketContentsLeft(int shiftAmount, int preShiftZeroIndex)
(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, 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, recordedValues, recordValue, recordValue, recordValueWithCount, recordValueWithExpectedInterval, reset, 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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totalCountUpdater
static final java.util.concurrent.atomic.AtomicLongFieldUpdater<ConcurrentHistogram> totalCountUpdater
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totalCount
volatile long totalCount
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activeCounts
volatile ConcurrentHistogram.ConcurrentArrayWithNormalizingOffset activeCounts
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inactiveCounts
volatile ConcurrentHistogram.ConcurrentArrayWithNormalizingOffset inactiveCounts
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wrp
transient WriterReaderPhaser wrp
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Constructor Detail
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ConcurrentHistogram
public ConcurrentHistogram(int numberOfSignificantValueDigits)
Construct an auto-resizing ConcurrentHistogram 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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ConcurrentHistogram
public ConcurrentHistogram(long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a ConcurrentHistogram 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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ConcurrentHistogram
public ConcurrentHistogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a ConcurrentHistogram 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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ConcurrentHistogram
public ConcurrentHistogram(AbstractHistogram source)
Construct a histogram 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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ConcurrentHistogram
ConcurrentHistogram(AbstractHistogram source, boolean allocateCountsArray)
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ConcurrentHistogram
ConcurrentHistogram(long lowestDiscernibleValue, long highestTrackableValue, int numberOfSignificantValueDigits, boolean allocateCountsArray)
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Method Detail
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setIntegerToDoubleValueConversionRatio
void setIntegerToDoubleValueConversionRatio(double integerToDoubleValueConversionRatio)
- Overrides:
setIntegerToDoubleValueConversionRatio
in classHistogram
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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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recordConvertedDoubleValue
void recordConvertedDoubleValue(double value)
- Overrides:
recordConvertedDoubleValue
in classAbstractHistogram
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recordConvertedDoubleValueWithCount
public void recordConvertedDoubleValueWithCount(double value, long count) throws java.lang.ArrayIndexOutOfBoundsException
- Overrides:
recordConvertedDoubleValueWithCount
in classAbstractHistogram
- Throws:
java.lang.ArrayIndexOutOfBoundsException
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getNormalizingIndexOffset
int getNormalizingIndexOffset()
- Overrides:
getNormalizingIndexOffset
in classHistogram
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setNormalizingIndexOffset
void setNormalizingIndexOffset(int normalizingIndexOffset)
- Overrides:
setNormalizingIndexOffset
in classHistogram
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setNormalizingIndexOffset
private void setNormalizingIndexOffset(int newNormalizingIndexOffset, int shiftedAmount, boolean lowestHalfBucketPopulated, double newIntegerToDoubleValueConversionRatio)
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setNormalizingIndexOffsetForInactive
private void setNormalizingIndexOffsetForInactive(int newNormalizingIndexOffset, int shiftedAmount, boolean lowestHalfBucketPopulated, double newIntegerToDoubleValueConversionRatio)
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shiftLowestInactiveHalfBucketContentsLeft
private void shiftLowestInactiveHalfBucketContentsLeft(int shiftAmount, int preShiftZeroIndex)
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shiftNormalizingIndexByOffset
void shiftNormalizingIndexByOffset(int offsetToAdd, boolean lowestHalfBucketPopulated, double newIntegerToDoubleValueConversionRatio)
- Overrides:
shiftNormalizingIndexByOffset
in classHistogram
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allocateArray
ConcurrentHistogram.ConcurrentArrayWithNormalizingOffset allocateArray(int length, int normalizingIndexOffset)
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copyInactiveCountsContentsOnResize
void copyInactiveCountsContentsOnResize(ConcurrentHistogram.ConcurrentArrayWithNormalizingOffset oldInactiveCounts, int countsDelta)
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setAutoResize
public void setAutoResize(boolean autoResize)
Description copied from class:AbstractHistogram
Control whether or not the histogram can auto-resize and auto-adjust it's highestTrackableValue- Overrides:
setAutoResize
in classAbstractHistogram
- Parameters:
autoResize
- autoResize setting
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clearCounts
void clearCounts()
- Overrides:
clearCounts
in classHistogram
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copy
public ConcurrentHistogram copy()
Description copied from class:AbstractHistogram
Create a copy of this histogram, complete with data and everything.
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copyCorrectedForCoordinatedOmission
public ConcurrentHistogram 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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getTotalCount
public long getTotalCount()
Description copied from class:AbstractHistogram
Get the total count of all recorded values in the histogram- Overrides:
getTotalCount
in classHistogram
- Returns:
- the total count of all recorded values in the histogram
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setTotalCount
void setTotalCount(long totalCount)
- Overrides:
setTotalCount
in classHistogram
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incrementTotalCount
void incrementTotalCount()
- Overrides:
incrementTotalCount
in classHistogram
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addToTotalCount
void addToTotalCount(long value)
- Overrides:
addToTotalCount
in classHistogram
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_getEstimatedFootprintInBytes
int _getEstimatedFootprintInBytes()
- Overrides:
_getEstimatedFootprintInBytes
in classHistogram
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decodeFromByteBuffer
public static ConcurrentHistogram 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 ConcurrentHistogram 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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fromString
public static ConcurrentHistogram fromString(java.lang.String base64CompressedHistogramString) throws java.util.zip.DataFormatException
Construct a new ConcurrentHistogram 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 ConcurrentHistogram decoded from the string
- Throws:
java.util.zip.DataFormatException
- on error parsing/decompressing the input
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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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fillBufferFromCountsArray
void fillBufferFromCountsArray(java.nio.ByteBuffer buffer)
- Overrides:
fillBufferFromCountsArray
in classAbstractHistogram
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