org.HdrHistogram
Class ShortHistogram

java.lang.Object
  org.HdrHistogram.AbstractHistogram
      org.HdrHistogram.ShortHistogram

All Implemented Interfaces:

Serializable

public class ShortHistogram
extends AbstractHistogram

A High Dynamic Range (HDR) Histogram using a short count type

See package description for org.HdrHistogram for details.

See Also:

Serialized Form

Constructor Summary

ShortHistogram(long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a ShortHistogram given the Highest value to be tracked and a number of significant decimal digits.

ShortHistogram(long lowestTrackableValue, long highestTrackableValue, int numberOfSignificantValueDigits)
Construct a ShortHistogram given the Lowest and Highest values to be tracked and a number of significant decimal digits.

Method Summary

ShortHistogram	copy() Create a copy of this histogram, complete with data and everything.
ShortHistogram	copyCorrectedForCoordinatedOmission(long expectedIntervalBetweenValueSamples) Get a copy of this histogram, corrected for coordinated omission.
static ShortHistogram	decodeFromByteBuffer(ByteBuffer buffer, long minBarForHighestTrackableValue) Construct a new histogram by decoding it from a ByteBuffer.
static ShortHistogram	decodeFromCompressedByteBuffer(ByteBuffer buffer, long minBarForHighestTrackableValue) Construct a new histogram by decoding it from a compressed form in a ByteBuffer.

Methods inherited from class org.HdrHistogram.AbstractHistogram

add, addWhileCorrectingForCoordinatedOmission, copyInto, copyIntoCorrectedForCoordinatedOmission, encodeIntoByteBuffer, encodeIntoCompressedByteBuffer, encodeIntoCompressedByteBuffer, equals, getEndTimeStamp, getEstimatedFootprintInBytes, getHighestTrackableValue, getHistogramData, getLowestTrackableValue, getNeededByteBufferCapacity, getNumberOfSignificantValueDigits, getStartTimeStamp, hasOverflowed, highestEquivalentValue, lowestEquivalentValue, medianEquivalentValue, nextNonEquivalentValue, recordValue, recordValue, recordValueWithCount, recordValueWithExpectedInterval, reestablishTotalCount, reset, setEndTimeStamp, setStartTimeStamp, sizeOfEquivalentValueRange, valuesAreEquivalent

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ShortHistogram

public ShortHistogram(long highestTrackableValue,
                      int numberOfSignificantValueDigits)

Construct a ShortHistogram 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 - 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.

ShortHistogram

public ShortHistogram(long lowestTrackableValue,
                      long highestTrackableValue,
                      int numberOfSignificantValueDigits)

Construct a ShortHistogram given the Lowest and Highest values to be tracked and a number of significant decimal digits. Providing a lowestTrackableValue 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 lowestTrackableValue would be 1000.

Parameters:

lowestTrackableValue - 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 * lowestTrackableValue).

numberOfSignificantValueDigits - 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.

Method Detail

copy

public ShortHistogram copy()

Description copied from class: AbstractHistogram

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

Specified by:

copy in class AbstractHistogram

Returns:

A distinct copy of this histogram.

copyCorrectedForCoordinatedOmission

public ShortHistogram 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. by

See notes in the description of the Histogram calls for an illustration of why this corrective behavior is important.

Specified by:

copyCorrectedForCoordinatedOmission in class AbstractHistogram

Parameters:

expectedIntervalBetweenValueSamples - If expectedIntervalBetweenValueSamples is larger than 0, add auto-generated value records as appropriate if value is larger than expectedIntervalBetweenValueSamples

decodeFromByteBuffer

public static ShortHistogram decodeFromByteBuffer(ByteBuffer buffer,
                                                  long minBarForHighestTrackableValue)

Construct a new histogram by decoding it from a ByteBuffer.

Parameters:

buffer - The buffer to decode from

minBarForHighestTrackableValue - Force highestTrackableValue to be set at least this high

Returns:

The newly constructed histogram

decodeFromCompressedByteBuffer

public static ShortHistogram decodeFromCompressedByteBuffer(ByteBuffer buffer,
                                                            long minBarForHighestTrackableValue)
                                                     throws DataFormatException

Construct a new histogram by decoding it from a compressed form in a ByteBuffer.

Parameters:

buffer - The buffer to encode into

minBarForHighestTrackableValue - Force highestTrackableValue to be set at least this high

Returns:

The newly constructed histogram

Throws:

DataFormatException