public class DoubleHistogram extends EncodableHistogram implements Serializable
It is important to note that DoubleHistogram
is not threadsafe, and does not support safe concurrent
recording by multiple threads. If concurrent operation is required, consider usings
ConcurrentDoubleHistogram
, SynchronizedDoubleHistogram
, or(recommended)
DoubleRecorder
, which are intended for this purpose.
DoubleHistogram
supports the recording and analyzing sampled data value counts across a
configurable dynamic range of floating point (double) values, with configurable value precision within the range.
Dynamic range is expressed as a ratio between the highest and lowest nonzero values trackable within the histogram
at any given time. Value precision is expressed as the number of significant [decimal] 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.
Autoranging: Unlike integer value based histograms, the specific value range tracked by a DoubleHistogram
is not specified upfront. Only the dynamic range of values that the histogram can cover is
(optionally) specified. E.g. When a DoubleHistogram
is created to track a dynamic range of
3600000000000 (enough to track values from a nanosecond to an hour), values could be recorded into into it in any
consistent unit of time as long as the ratio between the highest and lowest nonzero values stays within the
specified dynamic range, so recording in units of nanoseconds (1.0 thru 3600000000000.0), milliseconds (0.000001
thru 3600000.0) seconds (0.000000001 thru 3600.0), hours (1/3.6E12 thru 1.0) will all work just as well.
Autoresizing: When constructed with no specified dynamic range (or when autoresize is turned on with setAutoResize(boolean)
) a DoubleHistogram
will autoresize its dynamic range to
include recorded values as they are encountered. Note that recording calls that cause autoresizing may take
longer to execute, as resizing incurs allocation and copying of internal data structures.
Attempts to record nonzero values that range outside of the specified dynamic range (or exceed the limits of
of dynamic range when autoresizing) may results in ArrayIndexOutOfBoundsException
exceptions, either
due to overflow or underflow conditions. These exceptions will only be thrown if recording the value would have
resulted in discarding or losing the required value precision of values already recorded in the histogram.
See package description for org.HdrHistogram
for details.
Modifier and Type  Class and Description 

class 
DoubleHistogram.AllValues

class 
DoubleHistogram.LinearBucketValues

class 
DoubleHistogram.LogarithmicBucketValues

class 
DoubleHistogram.Percentiles

class 
DoubleHistogram.RecordedValues
An
Iterable <DoubleHistogramIterationValue > through
the histogram using a DoubleRecordedValuesIterator 
Modifier  Constructor and Description 


DoubleHistogram(DoubleHistogram source)
Construct a
DoubleHistogram with the same range settings as a given source,
duplicating the source's start/end timestamps (but NOT it's contents) 

DoubleHistogram(int numberOfSignificantValueDigits)
Construct a new autoresizing DoubleHistogram using a precision stated as a number
of significant decimal digits.


DoubleHistogram(int numberOfSignificantValueDigits,
Class<? extends AbstractHistogram> internalCountsHistogramClass)
Construct a new autoresizing DoubleHistogram using a precision stated as a number
of significant decimal digits.


DoubleHistogram(long highestToLowestValueRatio,
int numberOfSignificantValueDigits)
Construct a new DoubleHistogram with the specified dynamic range (provided in
highestToLowestValueRatio ) and using a precision stated as a number of significant
decimal digits. 
protected 
DoubleHistogram(long highestToLowestValueRatio,
int numberOfSignificantValueDigits,
Class<? extends AbstractHistogram> internalCountsHistogramClass)
Construct a new DoubleHistogram with the specified dynamic range (provided in
highestToLowestValueRatio ) and using a precision stated as a number of significant
decimal digits. 
Modifier and Type  Method and Description 

void 
add(DoubleHistogram fromHistogram)
Add the contents of another histogram to this one.

void 
addWhileCorrectingForCoordinatedOmission(DoubleHistogram fromHistogram,
double expectedIntervalBetweenValueSamples)
Add the contents of another histogram to this one, while correcting the incoming data for coordinated omission.

DoubleHistogram.AllValues 
allValues()
Provide a means of iterating through all histogram values using the finest granularity steps supported by
the underlying representation.

DoubleHistogram 
copy()
Create a copy of this histogram, complete with data and everything.

DoubleHistogram 
copyCorrectedForCoordinatedOmission(double expectedIntervalBetweenValueSamples)
Get a copy of this histogram, corrected for coordinated omission.

void 
copyInto(DoubleHistogram targetHistogram)
Copy this histogram into the target histogram, overwriting it's contents.

void 
copyIntoCorrectedForCoordinatedOmission(DoubleHistogram targetHistogram,
double expectedIntervalBetweenValueSamples)
Copy this histogram, corrected for coordinated omission, into the target histogram, overwriting it's contents.

static DoubleHistogram 
decodeFromByteBuffer(ByteBuffer buffer,
Class<? extends AbstractHistogram> internalCountsHistogramClass,
long minBarForHighestToLowestValueRatio)
Construct a new DoubleHistogram by decoding it from a ByteBuffer, using a
specified AbstractHistogram subclass for tracking internal counts (e.g.

static DoubleHistogram 
decodeFromByteBuffer(ByteBuffer buffer,
long minBarForHighestToLowestValueRatio)
Construct a new DoubleHistogram by decoding it from a ByteBuffer.

static DoubleHistogram 
decodeFromCompressedByteBuffer(ByteBuffer buffer,
Class<? extends AbstractHistogram> internalCountsHistogramClass,
long minBarForHighestToLowestValueRatio)
Construct a new DoubleHistogram by decoding it from a compressed form in a ByteBuffer, using a
specified AbstractHistogram subclass for tracking internal counts (e.g.

static DoubleHistogram 
decodeFromCompressedByteBuffer(ByteBuffer buffer,
long minBarForHighestToLowestValueRatio)
Construct a new DoubleHistogram by decoding it from a compressed form in a ByteBuffer.

int 
encodeIntoByteBuffer(ByteBuffer buffer)
Encode this histogram into a ByteBuffer

int 
encodeIntoCompressedByteBuffer(ByteBuffer targetBuffer)
Encode this histogram in compressed form into a byte array

int 
encodeIntoCompressedByteBuffer(ByteBuffer targetBuffer,
int compressionLevel)
Encode this histogram in compressed form into a byte array

boolean 
equals(Object other)
Determine if this histogram is equivalent to another.

long 
getCountAtValue(double value)
Get the count of recorded values at a specific value (to within the histogram resolution at the value level).

double 
getCountBetweenValues(double lowValue,
double highValue)
Get the count of recorded values within a range of value levels (inclusive to within the histogram's resolution).

long 
getEndTimeStamp()
get the end time stamp [optionally] stored with this histogram

int 
getEstimatedFootprintInBytes()
Provide a (conservatively high) estimate of the Histogram's total footprint in bytes

long 
getHighestToLowestValueRatio()
get the Dynamic range of the histogram: the configured ratio between the highest trackable value and the
lowest trackable non zero value at any given time.

double 
getIntegerToDoubleValueConversionRatio()
Get the current conversion ratio from interval integer value representation to double units.

double 
getMaxValue()
Get the highest recorded value level in the histogram

double 
getMaxValueAsDouble()
Get the highest recorded value level in the histogram as a double

double 
getMean()
Get the computed mean value of all recorded values in the histogram

double 
getMinNonZeroValue()
Get the lowest recorded nonzero value level in the histogram

double 
getMinValue()
Get the lowest recorded value level in the histogram

int 
getNeededByteBufferCapacity()
Get the capacity needed to encode this histogram into a ByteBuffer

int 
getNumberOfSignificantValueDigits()
get the configured numberOfSignificantValueDigits

double 
getPercentileAtOrBelowValue(double value)
Get the percentile at a given value.

long 
getStartTimeStamp()
get the start time stamp [optionally] stored with this histogram

double 
getStdDeviation()
Get the computed standard deviation of all recorded values in the histogram

String 
getTag()
get the tag string [optionally] associated with this histogram

long 
getTotalCount()
Get the total count of all recorded values in the histogram

double 
getValueAtPercentile(double percentile)
Get the value at a given percentile.

int 
hashCode() 
double 
highestEquivalentValue(double value)
Get the highest value that is equivalent to the given value within the histogram's resolution.

boolean 
isAutoResize() 
DoubleHistogram.LinearBucketValues 
linearBucketValues(double valueUnitsPerBucket)
Provide a means of iterating through histogram values using linear steps.

DoubleHistogram.LogarithmicBucketValues 
logarithmicBucketValues(double valueUnitsInFirstBucket,
double logBase)
Provide a means of iterating through histogram values at logarithmically increasing levels.

double 
lowestEquivalentValue(double value)
Get the lowest value that is equivalent to the given value within the histogram's resolution.

double 
medianEquivalentValue(double value)
Get a value that lies in the middle (rounded up) of the range of values equivalent the given value.

double 
nextNonEquivalentValue(double value)
Get the next value that is not equivalent to the given value within the histogram's resolution.

void 
outputPercentileDistribution(PrintStream printStream,
Double outputValueUnitScalingRatio)
Produce textual representation of the value distribution of histogram data by percentile.

void 
outputPercentileDistribution(PrintStream printStream,
int percentileTicksPerHalfDistance,
Double outputValueUnitScalingRatio)
Produce textual representation of the value distribution of histogram data by percentile.

void 
outputPercentileDistribution(PrintStream printStream,
int percentileTicksPerHalfDistance,
Double outputValueUnitScalingRatio,
boolean useCsvFormat)
Produce textual representation of the value distribution of histogram data by percentile.

DoubleHistogram.Percentiles 
percentiles(int percentileTicksPerHalfDistance)
Provide a means of iterating through histogram values according to percentile levels.

DoubleHistogram.RecordedValues 
recordedValues()
Provide a means of iterating through all recorded histogram values using the finest granularity steps
supported by the underlying representation.

void 
recordValue(double value)
Record a value in the histogram

void 
recordValueWithCount(double value,
long count)
Record a value in the histogram (adding to the value's current count)

void 
recordValueWithExpectedInterval(double value,
double expectedIntervalBetweenValueSamples)
Record a value in the histogram.

void 
reset()
Reset the contents and stats of this histogram

void 
setAutoResize(boolean autoResize) 
void 
setEndTimeStamp(long timeStampMsec)
Set the end time stamp value associated with this histogram to a given value.

void 
setStartTimeStamp(long timeStampMsec)
Set the start time stamp value associated with this histogram to a given value.

void 
setTag(String tag)
Set the tag string associated with this histogram

double 
sizeOfEquivalentValueRange(double value)
Get the size (in value units) of the range of values that are equivalent to the given value within the
histogram's resolution.

void 
subtract(DoubleHistogram otherHistogram)
Subtract the contents of another histogram from this one.

boolean 
valuesAreEquivalent(double value1,
double value2)
Determine if two values are equivalent with the histogram's resolution.

public DoubleHistogram(int numberOfSignificantValueDigits)
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 nonnegative integer between 0 and 5.public DoubleHistogram(int numberOfSignificantValueDigits, Class<? extends AbstractHistogram> internalCountsHistogramClass)
DoubleHistogram
will use the specified AbstractHistogram subclass
for tracking internal counts (e.g. Histogram
,
ConcurrentHistogram
, SynchronizedHistogram
,
IntCountsHistogram
, ShortCountsHistogram
).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 nonnegative integer between 0 and 5.internalCountsHistogramClass
 The class to use for internal counts trackingpublic DoubleHistogram(long highestToLowestValueRatio, int numberOfSignificantValueDigits)
highestToLowestValueRatio
) and using a precision stated as a number of significant
decimal digits.highestToLowestValueRatio
 specifies the dynamic range to usenumberOfSignificantValueDigits
 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 nonnegative integer between 0 and 5.protected DoubleHistogram(long highestToLowestValueRatio, int numberOfSignificantValueDigits, Class<? extends AbstractHistogram> internalCountsHistogramClass)
highestToLowestValueRatio
) and using a precision stated as a number of significant
decimal digits.
The DoubleHistogram
will use the specified AbstractHistogram subclass
for tracking internal counts (e.g. Histogram
,
ConcurrentHistogram
, SynchronizedHistogram
,
IntCountsHistogram
, ShortCountsHistogram
).highestToLowestValueRatio
 specifies the dynamic range to use.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 nonnegative integer between 0 and 5.internalCountsHistogramClass
 The class to use for internal counts trackingpublic DoubleHistogram(DoubleHistogram source)
DoubleHistogram
with the same range settings as a given source,
duplicating the source's start/end timestamps (but NOT it's contents)source
 The source histogram to duplicatepublic boolean isAutoResize()
public void setAutoResize(boolean autoResize)
public void recordValue(double value) throws ArrayIndexOutOfBoundsException
value
 The value to be recordedArrayIndexOutOfBoundsException
 (may throw) if value is cannot be covered by the histogram's rangepublic void recordValueWithCount(double value, long count) throws ArrayIndexOutOfBoundsException
value
 The value to be recordedcount
 The number of occurrences of this value to recordArrayIndexOutOfBoundsException
 (may throw) if value is cannot be covered by the histogram's rangepublic void recordValueWithExpectedInterval(double value, double expectedIntervalBetweenValueSamples) throws ArrayIndexOutOfBoundsException
To compensate for the loss of sampled values when a recorded value is larger than the expected interval between value samples, Histogram will autogenerate an additional series of decreasinglysmaller (down to the expectedIntervalBetweenValueSamples) value records.
Note: This is a atrecording correction method, as opposed to the postrecording correction method provided
by copyCorrectedForCoordinatedOmission(double)
.
The use cases for these 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.
See notes in the description of the Histogram calls for an illustration of why this corrective behavior is important.
value
 The value to recordexpectedIntervalBetweenValueSamples
 If expectedIntervalBetweenValueSamples is larger than 0, add
autogenerated value records as appropriate if value is larger
than expectedIntervalBetweenValueSamplesArrayIndexOutOfBoundsException
 (may throw) if value is cannot be covered by the histogram's rangepublic void reset()
public DoubleHistogram copy()
public DoubleHistogram copyCorrectedForCoordinatedOmission(double expectedIntervalBetweenValueSamples)
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 autogenerated additional series of
decreasinglysmaller (down to the expectedIntervalBetweenValueSamples) value records for each count found
in the current histogram that is larger than the expectedIntervalBetweenValueSamples.
Note: This is a postcorrection method, as opposed to the atrecording 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.
by
See notes in the description of the Histogram calls for an illustration of why this corrective behavior is important.
expectedIntervalBetweenValueSamples
 If expectedIntervalBetweenValueSamples is larger than 0, add
autogenerated value records as appropriate if value is larger
than expectedIntervalBetweenValueSamplespublic void copyInto(DoubleHistogram targetHistogram)
targetHistogram
 the histogram to copy intopublic void copyIntoCorrectedForCoordinatedOmission(DoubleHistogram targetHistogram, double expectedIntervalBetweenValueSamples)
copyCorrectedForCoordinatedOmission(double)
for more detailed explanation about how correction is applied)targetHistogram
 the histogram to copy intoexpectedIntervalBetweenValueSamples
 If expectedIntervalBetweenValueSamples is larger than 0, add
autogenerated value records as appropriate if value is larger
than expectedIntervalBetweenValueSamplespublic void add(DoubleHistogram fromHistogram) throws ArrayIndexOutOfBoundsException
fromHistogram
 The other histogram.ArrayIndexOutOfBoundsException
 (may throw) if values in fromHistogram's cannot be
covered by this histogram's rangepublic void addWhileCorrectingForCoordinatedOmission(DoubleHistogram fromHistogram, double expectedIntervalBetweenValueSamples)
To compensate for the loss of sampled values when a recorded value is larger than the expected
interval between value samples, the values added will include an autogenerated additional series of
decreasinglysmaller (down to the expectedIntervalBetweenValueSamples) value records for each count found
in the current histogram that is larger than the expectedIntervalBetweenValueSamples.
Note: This is a postrecording correction method, as opposed to the atrecording 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.
by
See notes in the description of the Histogram calls for an illustration of why this corrective behavior is important.
fromHistogram
 Other histogram. highestToLowestValueRatio and numberOfSignificantValueDigits must match.expectedIntervalBetweenValueSamples
 If expectedIntervalBetweenValueSamples is larger than 0, add
autogenerated value records as appropriate if value is larger
than expectedIntervalBetweenValueSamplesArrayIndexOutOfBoundsException
 (may throw) if values exceed highestTrackableValuepublic void subtract(DoubleHistogram otherHistogram)
otherHistogram
 The other histogram.ArrayIndexOutOfBoundsException
 (may throw) if values in fromHistogram's cannot be
covered by this histogram's rangepublic boolean equals(Object other)
public long getTotalCount()
public double getIntegerToDoubleValueConversionRatio()
getDoubleValueIteratedTo()
and
getDoubleValueIteratedFrom()
accessors to HistogramIterationValue
iterated values.public int getNumberOfSignificantValueDigits()
public long getHighestToLowestValueRatio()
public double sizeOfEquivalentValueRange(double value)
value
 The given valuepublic double lowestEquivalentValue(double value)
value
 The given valuepublic double highestEquivalentValue(double value)
value
 The given valuepublic double medianEquivalentValue(double value)
value
 The given valuepublic double nextNonEquivalentValue(double value)
value
 The given valuepublic boolean valuesAreEquivalent(double value1, double value2)
value1
 first value to comparevalue2
 second value to comparepublic int getEstimatedFootprintInBytes()
public long getStartTimeStamp()
getStartTimeStamp
in class EncodableHistogram
public void setStartTimeStamp(long timeStampMsec)
setStartTimeStamp
in class EncodableHistogram
timeStampMsec
 the value to set the time stamp to, [by convention] in msec since the epoch.public long getEndTimeStamp()
getEndTimeStamp
in class EncodableHistogram
public void setEndTimeStamp(long timeStampMsec)
setEndTimeStamp
in class EncodableHistogram
timeStampMsec
 the value to set the time stamp to, [by convention] in msec since the epoch.public String getTag()
getTag
in class EncodableHistogram
public void setTag(String tag)
setTag
in class EncodableHistogram
tag
 the tag string to assciate with this histogrampublic double getMinValue()
public double getMaxValue()
public double getMinNonZeroValue()
public double getMaxValueAsDouble()
getMaxValueAsDouble
in class EncodableHistogram
public double getMean()
public double getStdDeviation()
public double getValueAtPercentile(double percentile)
Note that two values are "equivalent" in this statement if
valuesAreEquivalent(double, double)
would return true.
percentile
 The percentile for which to return the associated valuepublic double getPercentileAtOrBelowValue(double value)
Note that two values are "equivalent" in this statement if
valuesAreEquivalent(double, double)
would return true.
value
 The value for which to return the associated percentilepublic double getCountBetweenValues(double lowValue, double highValue) throws ArrayIndexOutOfBoundsException
lowValue
 The lower value bound on the range for which
to provide the recorded count. Will be rounded down with
lowestEquivalentValue
.highValue
 The higher value bound on the range for which to provide the recorded count.
Will be rounded up with highestEquivalentValue
.ArrayIndexOutOfBoundsException
public long getCountAtValue(double value) throws ArrayIndexOutOfBoundsException
value
 The value for which to provide the recorded countArrayIndexOutOfBoundsException
public DoubleHistogram.Percentiles percentiles(int percentileTicksPerHalfDistance)
percentileTicksPerHalfDistance
 The number of iteration steps per halfdistance to 100%.Iterable
<DoubleHistogramIterationValue
>
through the histogram using a
DoublePercentileIterator
public DoubleHistogram.LinearBucketValues linearBucketValues(double valueUnitsPerBucket)
valueUnitsPerBucket
 The size (in value units) of the linear buckets to useIterable
<DoubleHistogramIterationValue
>
through the histogram using a
DoubleLinearIterator
public DoubleHistogram.LogarithmicBucketValues logarithmicBucketValues(double valueUnitsInFirstBucket, double logBase)
valueUnitsInFirstBucket
 The size (in value units) of the first bucket in the iterationlogBase
 The multiplier by which bucket sizes will grow in each iteration stepIterable
<DoubleHistogramIterationValue
>
through the histogram using
a DoubleLogarithmicIterator
public DoubleHistogram.RecordedValues recordedValues()
Iterable
<DoubleHistogramIterationValue
>
through the histogram using
a DoubleRecordedValuesIterator
public DoubleHistogram.AllValues allValues()
Iterable
<DoubleHistogramIterationValue
>
through the histogram using a DoubleAllValuesIterator
public void outputPercentileDistribution(PrintStream printStream, Double outputValueUnitScalingRatio)
printStream
 Stream into which the distribution will be output
outputValueUnitScalingRatio
 The scaling factor by which to divide histogram recorded values units in
outputpublic void outputPercentileDistribution(PrintStream printStream, int percentileTicksPerHalfDistance, Double outputValueUnitScalingRatio)
printStream
 Stream into which the distribution will be output
percentileTicksPerHalfDistance
 The number of reporting points per exponentially decreasing halfdistance
outputValueUnitScalingRatio
 The scaling factor by which to divide histogram recorded values units in
outputpublic void outputPercentileDistribution(PrintStream printStream, int percentileTicksPerHalfDistance, Double outputValueUnitScalingRatio, boolean useCsvFormat)
printStream
 Stream into which the distribution will be output
percentileTicksPerHalfDistance
 The number of reporting points per exponentially decreasing halfdistance
outputValueUnitScalingRatio
 The scaling factor by which to divide histogram recorded values units in
outputuseCsvFormat
 Output in CSV format if true. Otherwise use plain text form.public int getNeededByteBufferCapacity()
getNeededByteBufferCapacity
in class EncodableHistogram
public int encodeIntoByteBuffer(ByteBuffer buffer)
buffer
 The buffer to encode intopublic int encodeIntoCompressedByteBuffer(ByteBuffer targetBuffer, int compressionLevel)
encodeIntoCompressedByteBuffer
in class EncodableHistogram
targetBuffer
 The buffer to encode intocompressionLevel
 Compression level (for java.util.zip.Deflater).public int encodeIntoCompressedByteBuffer(ByteBuffer targetBuffer)
targetBuffer
 The buffer to encode intopublic static DoubleHistogram decodeFromByteBuffer(ByteBuffer buffer, long minBarForHighestToLowestValueRatio)
buffer
 The buffer to decode fromminBarForHighestToLowestValueRatio
 Force highestTrackableValue to be set at least this highpublic static DoubleHistogram decodeFromByteBuffer(ByteBuffer buffer, Class<? extends AbstractHistogram> internalCountsHistogramClass, long minBarForHighestToLowestValueRatio)
Histogram
,
ConcurrentHistogram
, SynchronizedHistogram
,
IntCountsHistogram
, ShortCountsHistogram
).buffer
 The buffer to decode frominternalCountsHistogramClass
 The class to use for internal counts trackingminBarForHighestToLowestValueRatio
 Force highestTrackableValue to be set at least this highpublic static DoubleHistogram decodeFromCompressedByteBuffer(ByteBuffer buffer, long minBarForHighestToLowestValueRatio) throws DataFormatException
buffer
 The buffer to decode fromminBarForHighestToLowestValueRatio
 Force highestTrackableValue to be set at least this highDataFormatException
 on error parsing/decompressing the bufferpublic static DoubleHistogram decodeFromCompressedByteBuffer(ByteBuffer buffer, Class<? extends AbstractHistogram> internalCountsHistogramClass, long minBarForHighestToLowestValueRatio) throws DataFormatException
Histogram
,
AtomicHistogram
, SynchronizedHistogram
,
IntCountsHistogram
, ShortCountsHistogram
).buffer
 The buffer to decode frominternalCountsHistogramClass
 The class to use for internal counts trackingminBarForHighestToLowestValueRatio
 Force highestTrackableValue to be set at least this highDataFormatException
 on error parsing/decompressing the bufferCopyright © 2016. All rights reserved.