Counter (Java Simon 4.2.0 API)

All Superinterfaces:

HasAttributes, Simon
```
public interface Counter
extends Simon
```
Counter tracks the single integer value and watches its max/min values. It can be used for values starting with 0 - in that case min might not be important if counter does not go bellow 0. Counter can also start from any other arbitrary number that is set after the first change (increment, decrement, set) - this is more typical case for tracking also the min value.

Initialization
When a counter is created, it is set to 0, but its maximum/minimum values are undefined:
```
 Counter counter = SimonManager.getCounter("com.my.counter");
 System.out.println("counter = " + counter);
```
Output is:
```
 counter = Simon Counter: [com.my.counter INHERIT] counter=0, max=undef, min=undef
```
This behavior allows the counter to be initialized before it is used and its extremes are tracked - first initialization also sets max/min (extreme) values:
```
 Counter counter = SimonManager.getCounter("com.my.counter").set(47);
 System.out.println("counter = " + counter);
```
Output is:
```
 counter = Simon Counter: [com.my.counter INHERIT] counter=47, max=47, min=47
```
Usage
Typical Counter usage is based on increase() and decrease() methods when it is possible to track the monitored value - this can be used for example to count users logged in. If the value changes by more than 1 than it is possible to use methods with arguments - increase(long) and decrease(long). Finally method set(long) is always available to set the counter to the particular value when needed.
Author:

Richard "Virgo" Richter

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`Counter`	`decrease()` Decrements the counter by one.
`Counter`	`decrease(long dec)` Increments the counter by the specified value.
`long`	`getCounter()` Returns the current value of the counter.
`long`	`getDecrementSum()` Returns the sum of all decremented values (as a positive number).
`long`	`getIncrementSum()` Returns the sum of all incremented values.
`long`	`getMax()` Returns maximal value of counter.
`long`	`getMaxTimestamp()` Returns ms timestamp when the max value was reached.
`long`	`getMin()` Returns minimal value of counter.
`long`	`getMinTimestamp()` Returns ms timestamp when the min value was reached.
`Counter`	`increase()` Increments the counter by one.
`Counter`	`increase(long inc)` Increments the counter by the specified value.
`CounterSample`	`sample()` Samples Simon values and returns them in a Java Bean derived from Sample interface.
`CounterSample`	`sampleIncrement(Object key)` Samples increment in Simon values since the previous call of this method with the same key.
`CounterSample`	`sampleIncrementNoReset(Object key)` Samples current value of incremental Simon.
`Counter`	`set(long val)` Sets the value of the counter to specified value.

Methods inherited from interface org.javasimon.Simon
getChildren, getFirstUsage, getLastUsage, getManager, getName, getNote, getParent, getState, isEnabled, setNote, setState, stopIncrementalSampling

Methods inherited from interface org.javasimon.HasAttributes
getAttribute, getAttribute, getAttributeNames, getCopyAsSortedMap, removeAttribute, setAttribute

- Method Detail
  - increase
```
Counter increase()
```
    Increments the counter by one.
    
    Returns:
    
    this
  - decrease
```
Counter decrease()
```
    Decrements the counter by one.
    
    Returns:
    
    this
  - increase
```
Counter increase(long inc)
```
    Increments the counter by the specified value. Using negative values is possible but may provide unexpected results - this method updates only incrementSum, it is decreased when negative number is used. Min and max are updated as expected.
    
    Parameters:
    
    inc - added value
    
    Returns:
    
    this
  - decrease
```
Counter decrease(long dec)
```
    Increments the counter by the specified value. Using negative values is possible but may provide unexpected results - this method updates only decrementSum, it is decreased when negative number is used. Min and max are updated as expected.
    
    Parameters:
    
    dec - subtracted value
    
    Returns:
    
    this
  - getCounter
```
long getCounter()
```
    Returns the current value of the counter.
    
    Returns:
    
    counter value
  - getMin
```
long getMin()
```
    Returns minimal value of counter. Updated by decrease(), decrease(long) and set(long).
    
    Returns:
    
    maximal reached value
  - getMinTimestamp
```
long getMinTimestamp()
```
    Returns ms timestamp when the min value was reached.
    
    Returns:
    
    ms timestamp of the min value decremented
  - getMax
```
long getMax()
```
    Returns maximal value of counter. Updated by increase(), increase(long) and set(long).
    
    Returns:
    
    maximal reached value
  - getMaxTimestamp
```
long getMaxTimestamp()
```
    Returns ms timestamp when the max value was reached.
    
    Returns:
    
    ms timestamp of the max value incremented
  - set
```
Counter set(long val)
```
    Sets the value of the counter to specified value.
    
    Parameters:
    
    val - new counter value
    
    Returns:
    
    this
  - getIncrementSum
```
long getIncrementSum()
```
    Returns the sum of all incremented values. If incremented value was negative, sum is lowered by this value.
    
    Returns:
    
    sum of all incremented values
  - getDecrementSum
```
long getDecrementSum()
```
    Returns the sum of all decremented values (as a positive number). If decremented value was negative, sum is lowered by this value.
    
    Returns:
    
    sum of all decremented values
  - sample
```
CounterSample sample()
```
    Description copied from interface: Simon
    
    Samples Simon values and returns them in a Java Bean derived from Sample interface.
    
    Specified by:
    
    sample in interface Simon
    
    Returns:
    
    sample containing all Simon values
  - sampleIncrement
```
CounterSample sampleIncrement(Object key)
```
    Description copied from interface: Simon
    
    Samples increment in Simon values since the previous call of this method with the same key. When the method is called the first time for the key, current values are returned (same like from Simon.sample(). Any subsequent calls with the key provide increments.
    Clients can use any sampling key (any Object) which enables safe access to their own increments. Using String does not guarantee this as any client can potentially guess the key. This may or may not be an issue.
    
    Specified by:
    
    sampleIncrement in interface Simon
    
    Parameters:
    
    key - sampling key used to access incremental sample
    
    Returns:
    
    Sample with value increments
  - sampleIncrementNoReset
```
CounterSample sampleIncrementNoReset(Object key)
```
    Description copied from interface: Simon
    
    Samples current value of incremental Simon. Works like Simon.sampleIncrement(Object) but does not reset the incremental Simon. This method does not start incremental sampling and keeps returning values from Simon.sample() for any key that was not used with Simon.sampleIncrement(Object) before.
    
    Specified by:
    
    sampleIncrementNoReset in interface Simon
    
    Parameters:
    
    key - sampling key used to access incremental sample
    
    Returns:
    
    Sample with value increments
    
    See Also:
    
    Simon.sampleIncrement(Object)

Interface Counter

Initialization

Usage

Method Summary

Methods inherited from interface org.javasimon.Simon

Methods inherited from interface org.javasimon.HasAttributes

Method Detail

increase

decrease

increase

decrease

getCounter

getMin

getMinTimestamp

getMax

getMaxTimestamp

set

getIncrementSum

getDecrementSum

sample

sampleIncrement

sampleIncrementNoReset