com.tomtom.speedtools.metrics

Class MetricsCollector

java.lang.Object

com.tomtom.speedtools.metrics.MetricsCollector

All Implemented Interfaces:

MetricsData

public class MetricsCollector
extends Object
implements MetricsData

Utility class to collect metrics data. It keeps track of a sum, count and average for the given time period. Not all values are maintained. Instead, the time period is divided in a number of entries, which constrains memory usage. The trade-off for this reduced memory usage is that statistics are not reported for EXACTLY given time period, but possibly for a slightly longer period. This class is thread-safe.

Constructor Summary

Constructors

Constructor and Description
MetricsCollector(org.joda.time.Duration totalMetricDuration, int maxEntries)

Method Summary

Modifier and Type	Method and Description
void	addValue(float value, org.joda.time.DateTime now) Adds a value to the collector.
void	addValueNow(float value) Adds a value to the collector.
static MetricsCollector	create(MultiMetricsData.Period interval)
float	getAvg() Return the average of all metric data added up until now since the duration (approx) of this metric.
int	getCount() Return the total number of metric data items added up until now since the duration (approx) of this metric.
float	getMax() Get maximum.
float	getMin() Get minimum.
List<MetricsTimeSlot>	getSlots() Retrieve the slots by which the metric is represented internally.
float	getStdDev() Get standard deviation.
float	getSum() Return the sum of all metric data added up until now since the duration (approx) of this metric.
org.joda.time.Duration	getTotalMetricDuration()
void	setSlots(Collection<MetricsTimeSlot> slots) Set the slots by which the metric is represented internally.

Methods inherited from class java.lang.Object

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

Constructor Detail

MetricsCollector

public MetricsCollector(@Nonnull
                        org.joda.time.Duration totalMetricDuration,
                        int maxEntries)

Method Detail

create

@Nonnull
public static MetricsCollector create(@Nonnull
                                               MultiMetricsData.Period interval)

getSlots

@Nonnull
public List<MetricsTimeSlot> getSlots()

Retrieve the slots by which the metric is represented internally. Mainly used for serialization.

Returns:

Metric slots.

setSlots

public void setSlots(@Nonnull
                     Collection<MetricsTimeSlot> slots)

Set the slots by which the metric is represented internally. Existing data will be overwritten. Mainly used for serialization.

Parameters:

slots - Metric slots.

getTotalMetricDuration

@Nonnull
public org.joda.time.Duration getTotalMetricDuration()

addValueNow

public void addValueNow(float value)

Adds a value to the collector.

Parameters:

value - Value to add.

addValue

public void addValue(float value,
                     @Nonnull
                     org.joda.time.DateTime now)

Adds a value to the collector. Use this method instead of addValueNow(float) when now is determined by the caller and should be aligned with other now-related functionality. Note that now should denote the current time and cannot be an arbitrary time in the past or the future.

Parameters:

value - Value to add.

now - Current time, as determined by the caller.

getCount

public int getCount()

Return the total number of metric data items added up until now since the duration (approx) of this metric.

Specified by:

getCount in interface MetricsData

Returns:

Total number of data items.

getSum

public float getSum()

Return the sum of all metric data added up until now since the duration (approx) of this metric.

Specified by:

getSum in interface MetricsData

Returns:

Sum of metric data.

getAvg

public float getAvg()

Return the average of all metric data added up until now since the duration (approx) of this metric.

Specified by:

getAvg in interface MetricsData

Returns:

Average of metric data, or Float.NaN if no data has been added.

getStdDev

public float getStdDev()

Get standard deviation.

Specified by:

getStdDev in interface MetricsData

Returns:

The the sample standard deviation of all metric data added up until now since the duration (approx) of this metric, or Float.NaN if no data has been added.

getMax

public float getMax()

Get maximum.

Specified by:

getMax in interface MetricsData

Returns:

The maximum value of all metric data added up until now since the duration (approx) of this metric, or Float.NaN if no data has been added.

getMin

public float getMin()

Get minimum.

Specified by:

getMin in interface MetricsData

Returns:

The minimum value of all metric data added up until now since the duration (approx) of this metric, or Float.NaN if no data has been added.