net.i2p.stat
Class Rate

java.lang.Object
  extended by net.i2p.stat.Rate

public class Rate
extends Object

Simple rate calculator for periodically sampled data points - determining an average value over a period, the number of events in that period, the maximum number of events (using the interval between events), and lifetime data. If value is always a constant, you should be using Frequency instead.


Constructor Summary
Rate(long period)
          A rate with period shorter than Router.COALESCE_TIME = 50*1000 has to be manually coalesced before values are fetched from it.
Rate(Properties props, String prefix, boolean treatAsCurrent)
          Create a new rate and load its state from the properties, taking data from the data points underneath the given prefix.
 
Method Summary
 void addData(long value)
          Accrue the data in the current period as an instantaneous event.
 void addData(long value, long eventDuration)
          Accrue the data in the current period as if the event took the specified amount of time If value is always a constant, you should be using Frequency instead.
 void coalesce()
           
 RateAverages computeAverages()
           
 RateAverages computeAverages(RateAverages out, boolean useLifetime)
           
 boolean equals(Object obj)
          This is used in StatSummarizer and SummaryListener.
 double getAverageValue()
          What was the average value across the events in the last period?
 double getAvgOrLifetimeAvg()
           
 long getCreationDate()
          when was this rate created?
 long getCurrentEventCount()
          in the current (partial) period, how many events have occurred?
 long getCurrentTotalEventTime()
          in the current (partial) period, how much of the time has been spent doing the events?
 double getCurrentTotalValue()
          in the current (partial) period, what is the total value acrued through all events?
 double getExtremeAverageValue()
          During the extreme period (i.e.
 long getExtremeEventCount()
          when the max(totalValue) was achieved, how many events occurred in that period? Note that this is not necesarily the highest event count; that isn't tracked.
 double getExtremeEventSaturation()
          During the extreme period (i.e.
 double getExtremeSaturationLimit()
          During the extreme period (i.e.
 long getExtremeTotalEventTime()
          when the max(totalValue) was achieved, how much of the time was spent doing the events?
 double getExtremeTotalValue()
          what was the max total value acrued in any period?
 long getLastCoalesceDate()
          when was the rate last coalesced?
 long getLastEventCount()
          in the last full period, how many events occurred?
 double getLastEventSaturation()
          During the last period, how much of the time was spent actually processing events in proportion to how many events could have occurred if there were no intervals?
 double getLastSaturationLimit()
          using the last period's rate, what is the total value that could have been sent if events were constant?
 long getLastTotalEventTime()
          in the last full period, how much of the time was spent doing the events?
 double getLastTotalValue()
          in the last full period, what was the total value acrued through all events?
 double getLifetimeAverageValue()
          What was the average value across the events since the stat was created?
 long getLifetimeEventCount()
          since rate creation, how many events have occurred?
 double getLifetimeEventSaturation()
          During the lifetime of this stat, how much of the time was spent actually processing events in proportion to how many events could have occurred if there were no intervals?
 long getLifetimePeriods()
          how many periods have we already completed?
 long getLifetimeTotalEventTime()
          since rate creation, how much of the time was spent doing the events?
 double getLifetimeTotalValue()
          since rate creation, what was the total value acrued through all events?
 double getPercentageOfExtremeValue()
          What was the total value, compared to the total value in the extreme period (i.e.
 double getPercentageOfLifetimeValue()
          How large was the last period's value as compared to the lifetime average value? Warning- returns ratio, not percentage (i.e.
 long getPeriod()
          how large should this rate's cycle be?
 RateStat getRateStat()
           
 RateSummaryListener getSummaryListener()
           
 int hashCode()
          It doesn't appear that Rates are ever stored in a Set or Map (RateStat stores in an array) so let's make this easy.
 void load(Properties props, String prefix, boolean treatAsCurrent)
          Load this rate from the properties, taking data from the data points underneath the given prefix.
 void setRateStat(RateStat rs)
           
 void setSummaryListener(RateSummaryListener listener)
           
 void store(String prefix, StringBuilder buf)
           
 String toString()
           
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

Rate

public Rate(long period)
     throws IllegalArgumentException
A rate with period shorter than Router.COALESCE_TIME = 50*1000 has to be manually coalesced before values are fetched from it.

Parameters:
period - number of milliseconds in the period this rate deals with, min 1, max Integer.MAX_VALUE
Throws:
IllegalArgumentException - if the period is invalid

Rate

public Rate(Properties props,
            String prefix,
            boolean treatAsCurrent)
     throws IllegalArgumentException
Create a new rate and load its state from the properties, taking data from the data points underneath the given prefix.

(e.g. prefix = "profile.dbIntroduction.60m", this will load the associated data points such as "profile.dbIntroduction.60m.lifetimeEventCount"). The data can be exported through store(outputStream, "profile.dbIntroduction.60m").

Parameters:
prefix - prefix to the property entries (should NOT end with a period)
treatAsCurrent - if true, we'll treat the loaded data as if no time has elapsed since it was written out, but if it is false, we'll treat the data with as much freshness (or staleness) as appropriate.
Throws:
IllegalArgumentException - if the data was formatted incorrectly
Method Detail

getCurrentTotalValue

public double getCurrentTotalValue()
in the current (partial) period, what is the total value acrued through all events?


getCurrentEventCount

public long getCurrentEventCount()
in the current (partial) period, how many events have occurred?


getCurrentTotalEventTime

public long getCurrentTotalEventTime()
in the current (partial) period, how much of the time has been spent doing the events?


getLastTotalValue

public double getLastTotalValue()
in the last full period, what was the total value acrued through all events?


getLastEventCount

public long getLastEventCount()
in the last full period, how many events occurred?


getLastTotalEventTime

public long getLastTotalEventTime()
in the last full period, how much of the time was spent doing the events?


getExtremeTotalValue

public double getExtremeTotalValue()
what was the max total value acrued in any period?


getExtremeEventCount

public long getExtremeEventCount()
when the max(totalValue) was achieved, how many events occurred in that period? Note that this is not necesarily the highest event count; that isn't tracked.


getExtremeTotalEventTime

public long getExtremeTotalEventTime()
when the max(totalValue) was achieved, how much of the time was spent doing the events?


getLifetimeTotalValue

public double getLifetimeTotalValue()
since rate creation, what was the total value acrued through all events?


getLifetimeEventCount

public long getLifetimeEventCount()
since rate creation, how many events have occurred?


getLifetimeTotalEventTime

public long getLifetimeTotalEventTime()
since rate creation, how much of the time was spent doing the events?


getLastCoalesceDate

public long getLastCoalesceDate()
when was the rate last coalesced?


getCreationDate

public long getCreationDate()
when was this rate created?


getPeriod

public long getPeriod()
how large should this rate's cycle be?


getRateStat

public RateStat getRateStat()

setRateStat

public void setRateStat(RateStat rs)

addData

public void addData(long value)
Accrue the data in the current period as an instantaneous event. If value is always a constant, you should be using Frequency instead. If you always use this call, eventDuration is always zero, and the various get*Saturation*() and get*EventTime() methods will return zero.


addData

public void addData(long value,
                    long eventDuration)
Accrue the data in the current period as if the event took the specified amount of time If value is always a constant, you should be using Frequency instead. If eventDuration is nonzero, then the various get*Saturation*() and get*EventTime() methods will also return nonzero.
 There are at least 4 possible strategies for eventDuration:

   1) eventDuration is always zero.
      The various get*Saturation*() and get*EventTime() methods will return zero.

   2) Each eventDuration is relatively small, and reflects processing time.
      This is probably the original meaning of "saturation", as it allows you
      to track how much time is spent gathering the stats.
      get*EventTime() will be close to 0.
      get*EventSaturation() will return values close to 0,
      get*SaturationLimit() will return adjusted values for the totals.

   3) The total of the eventDurations are approximately equal to total elapsed time.
      get*EventTime() will be close to the period.
      get*EventSaturation() will return values close to 1,
      get*SaturationLimit() will return adjusted values for the totals.

   4) Each eventDuration is not a duration at all, but someother independent data.
      get*EventTime() may be used to retrieve the data.
      get*EventSaturation() are probably useless.
      get*SaturationLimit() are probably useless.
 

Parameters:
value - value to accrue in the current period
eventDuration - how long it took to accrue this data (set to 0 if it was instantaneous)

coalesce

public void coalesce()

setSummaryListener

public void setSummaryListener(RateSummaryListener listener)

getSummaryListener

public RateSummaryListener getSummaryListener()

getAverageValue

public double getAverageValue()
What was the average value across the events in the last period?


getExtremeAverageValue

public double getExtremeAverageValue()
During the extreme period (i.e. the period with the highest total value), what was the average value?


getLifetimeAverageValue

public double getLifetimeAverageValue()
What was the average value across the events since the stat was created?


getAvgOrLifetimeAvg

public double getAvgOrLifetimeAvg()
Returns:
the average or lifetime average depending on last event count
Since:
0.9.4

getLastEventSaturation

public double getLastEventSaturation()
During the last period, how much of the time was spent actually processing events in proportion to how many events could have occurred if there were no intervals?

Returns:
ratio, or 0 if event times aren't used

getExtremeEventSaturation

public double getExtremeEventSaturation()
During the extreme period (i.e. the period with the highest total value), how much of the time was spent actually processing events in proportion to how many events could have occurred if there were no intervals?

Returns:
ratio, or 0 if the statistic doesn't use event times

getLifetimeEventSaturation

public double getLifetimeEventSaturation()
During the lifetime of this stat, how much of the time was spent actually processing events in proportion to how many events could have occurred if there were no intervals?

Returns:
ratio, or 0 if event times aren't used

getLifetimePeriods

public long getLifetimePeriods()
how many periods have we already completed?


getLastSaturationLimit

public double getLastSaturationLimit()
using the last period's rate, what is the total value that could have been sent if events were constant?

Returns:
max total value, or 0 if event times aren't used

getExtremeSaturationLimit

public double getExtremeSaturationLimit()
During the extreme period (i.e. the period with the highest total value), what is the total value that could have been sent if events were constant?

Returns:
event total at saturation, or 0 if no event times are measured

getPercentageOfExtremeValue

public double getPercentageOfExtremeValue()
What was the total value, compared to the total value in the extreme period (i.e. the period with the highest total value), Warning- returns ratio, not percentage (i.e. it is not multiplied by 100 here)


getPercentageOfLifetimeValue

public double getPercentageOfLifetimeValue()
How large was the last period's value as compared to the lifetime average value? Warning- returns ratio, not percentage (i.e. it is not multiplied by 100 here)


computeAverages

public RateAverages computeAverages()
Returns:
a thread-local temp object containing computed averages.
Since:
0.9.4

computeAverages

public RateAverages computeAverages(RateAverages out,
                                    boolean useLifetime)
Parameters:
out - where to store the computed averages.
useLifetime - whether the lifetime average should be used if there are no events.
Returns:
the same RateAverages object for chaining
Since:
0.9.4

store

public void store(String prefix,
                  StringBuilder buf)
           throws IOException
Throws:
IOException

load

public void load(Properties props,
                 String prefix,
                 boolean treatAsCurrent)
          throws IllegalArgumentException
Load this rate from the properties, taking data from the data points underneath the given prefix.

Parameters:
prefix - prefix to the property entries (should NOT end with a period)
treatAsCurrent - if true, we'll treat the loaded data as if no time has elapsed since it was written out, but if it is false, we'll treat the data with as much freshness (or staleness) as appropriate.
Throws:
IllegalArgumentException - if the data was formatted incorrectly

equals

public boolean equals(Object obj)
This is used in StatSummarizer and SummaryListener. We base it on the stat we are tracking, not the stored data.

Overrides:
equals in class Object

hashCode

public int hashCode()
It doesn't appear that Rates are ever stored in a Set or Map (RateStat stores in an array) so let's make this easy.

Overrides:
hashCode in class Object

toString

public String toString()
Overrides:
toString in class Object