FastLongHistogram (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.metrics.impl.FastLongHistogram

@InterfaceAudience.Private
@InterfaceStability.Evolving
public class FastLongHistogram
extends Object

FastLongHistogram is a thread-safe class that estimate distribution of data and computes the quantiles.

Field Summary

Fields
Modifier and Type Field and Description

static int DEFAULT_NBINS
Default number of bins.

static double[] DEFAULT_QUANTILES

Fields
Modifier and Type	Field and Description
`static int`	`DEFAULT_NBINS` Default number of bins.
`static double[]`	`DEFAULT_QUANTILES`

Constructor Summary

Constructors
Constructor and Description
`FastLongHistogram()` Constructor.
`FastLongHistogram(int numOfBins)` Constructor.
`FastLongHistogram(int numOfBins, long min, long max)` Constructor setting the bins assuming a uniform distribution within a range.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(long value, long count)` Adds a value to the histogram.
`long`	`getCount()`
`long`	`getMax()`
`long`	`getMean()`
`long`	`getMin()`
`long`	`getNumAtOrBelow(long value)`
`long[]`	`getQuantiles()`
`long[]`	`getQuantiles(double[] quantiles)` Computes the quantiles give the ratios.
`Snapshot`	`snapshotAndReset()` Resets the histogram for new counting.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_NBINS
```
public static final int DEFAULT_NBINS
```
    Default number of bins.
    
    See Also:
    Constant Field Values
  - DEFAULT_QUANTILES
```
public static final double[] DEFAULT_QUANTILES
```
- Constructor Detail
  - FastLongHistogram
```
public FastLongHistogram()
```
    Constructor.
  - FastLongHistogram
```
public FastLongHistogram(int numOfBins)
```
    Constructor.
    
    Parameters:
    numOfBins - the number of bins for the histogram. A larger value results in more precise results but with lower efficiency, and vice versus.
  - FastLongHistogram
```
public FastLongHistogram(int numOfBins,
                 long min,
                 long max)
```
    Constructor setting the bins assuming a uniform distribution within a range.
    
    Parameters:
    numOfBins - the number of bins for the histogram. A larger value results in more precise results but with lower efficiency, and vice versus.
    min - lower bound of the region, inclusive.
    max - higher bound of the region, inclusive.
- Method Detail
  - add
```
public void add(long value,
       long count)
```
    Adds a value to the histogram.
  - getQuantiles
```
public long[] getQuantiles(double[] quantiles)
```
    Computes the quantiles give the ratios.
  - getQuantiles
```
public long[] getQuantiles()
```
  - getMin
```
public long getMin()
```
  - getMax
```
public long getMax()
```
  - getCount
```
public long getCount()
```
  - getMean
```
public long getMean()
```
  - getNumAtOrBelow
```
public long getNumAtOrBelow(long value)
```
  - snapshotAndReset
```
public Snapshot snapshotAndReset()
```
    Resets the histogram for new counting.

Class FastLongHistogram

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_NBINS

DEFAULT_QUANTILES

Constructor Detail

FastLongHistogram

FastLongHistogram

FastLongHistogram

Method Detail

add

getQuantiles

getQuantiles

getMin

getMax

getCount

getMean

getNumAtOrBelow

snapshotAndReset