InstrumentRegistry (Atlassian Instrumentation Aggregation

All Known Implementing Classes:

DefaultInstrumentRegistry
```
public interface InstrumentRegistry
```
This is a glorified Map/Set of Instrument's.
It can create new Instrument objects directly via is pull() methods. This makes it easier to manage the creation of performance statistics.
Names of instruments MUST be unique. For example you cannot have a Counter and a Gauge with the same name. If an Instrument exists with the a specified name and its not of the requested type, then an IllegalStateException will be thrown.
THREAD SAFETY : ConcurrentHashMap is sued under the covers to ensure that @{link Instrument}s are created once and only once.

Since:

v4.0

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`Instrument`	`getInstrument(String name)` Returns an `Instrument` from the registry with the specified name
`int`	`getNumberOfInstruments()` Returns the number of instruments that exist.
`RegistryConfiguration`	`getRegistryConfiguration()`
`AbsoluteCounter`	`pullAbsoluteCounter(String name)` This is a pull through operation that guarantees to ATOMICALLY create a AbsoluteCounter under the name if its not present OR return the previously created one if its there.
`CacheCollector`	`pullCacheCollector(String name)` This is a pull through operation that guarantees to ATOMICALLY create a `CacheCounter` under the name if its not present OR return the previously created one if its there.
`CacheCollector`	`pullCacheCollector(String name, CacheCollector.Sizer sizer)` This is a pull through operation that guarantees to ATOMICALLY create a `CacheCollector` under the name if its not present OR return the previously created one if its there.
`CacheCounter`	`pullCacheCounter(String name)` This is a pull through operation that guarantees to ATOMICALLY create a `CacheCounter` under the name if its not present OR return the previously created one if its there.
`CacheCounter`	`pullCacheCounter(String name, CacheCounter.Sizer sizer)` This is a pull through operation that guarantees to ATOMICALLY create a `CacheCounter` under the name if its not present OR return the previously created one if its there.
`Counter`	`pullCounter(String name)` This is a pull through operation that guarantees to ATOMICALLY create a Counter under the name if its not present OR return the previously created one if its there.
`DerivedCounter`	`pullDerivedCounter(String name)` This is a pull through operation that guarantees to ATOMICALLY create a DerivedCounter under the name if its not present OR return the previously created one if its there.
`Gauge`	`pullGauge(String name)` This is a pull through operation that guarantees to ATOMICALLY create a Gauge under the name if its not present OR return the previously created one if its there.
`OpCounter`	`pullOpCounter(String name)` This is a pull through operation that guarantees to ATOMICALLY create an `OpCounter` under the name if its not present OR return the previously created one if its there.
`OpTimer`	`pullTimer(String name)` This is a pull through operation that guarantees to ATOMICALLY create a OpCounter under the name if its not present OR use the previously created one if its there.
`Instrument`	`putInstrument(Instrument instrument)` This will put an `Instrument` into the registry, atomically overwriting any previous `Instrument` value.
`List<Instrument>`	`snapshotInstruments()` This returns a snapshot list of `Instrument` objects in the InstrumentRegistry at the time the method was called.

- Method Detail
  - getRegistryConfiguration
```
RegistryConfiguration getRegistryConfiguration()
```
    Returns:
    
    the underlying registry configuration
  - putInstrument
```
Instrument putInstrument(Instrument instrument)
```
    This will put an Instrument into the registry, atomically overwriting any previous Instrument value.
    
    Parameters:
    
    instrument - the NON NULL instrument to add
    
    Returns:
    
    the previous Instrument value
  - getInstrument
```
Instrument getInstrument(String name)
```
    Returns an Instrument from the registry with the specified name
    
    Parameters:
    
    name - the name of the Instrument to return
    
    Returns:
    
    an Instrument or null if there isn't one with that name
  - pullAbsoluteCounter
```
AbsoluteCounter pullAbsoluteCounter(String name)
```
    This is a pull through operation that guarantees to ATOMICALLY create a AbsoluteCounter under the name if its not present OR return the previously created one if its there.
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    
    Parameters:
    
    name - the name of the DerivedCounter to pull
    
    Returns:
    
    a NON NULL DerivedCounter guaranteed
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a DerivedCounter
  - pullCounter
```
Counter pullCounter(String name)
```
    This is a pull through operation that guarantees to ATOMICALLY create a Counter under the name if its not present OR return the previously created one if its there.
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    
    Parameters:
    
    name - the name of the Counter to pull
    
    Returns:
    
    a NON NULL Counter guaranteed
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a Counter
  - pullDerivedCounter
```
DerivedCounter pullDerivedCounter(String name)
```
    This is a pull through operation that guarantees to ATOMICALLY create a DerivedCounter under the name if its not present OR return the previously created one if its there.
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    
    Parameters:
    
    name - the name of the DerivedCounter to pull
    
    Returns:
    
    a NON NULL DerivedCounter guaranteed
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a DerivedCounter
  - pullGauge
```
Gauge pullGauge(String name)
```
    This is a pull through operation that guarantees to ATOMICALLY create a Gauge under the name if its not present OR return the previously created one if its there.
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    
    Parameters:
    
    name - the name of the Gauge to pull
    
    Returns:
    
    a NON NULL Gauge guaranteed
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a Gauge
  - pullCacheCollector
```
CacheCollector pullCacheCollector(String name,
                                  CacheCollector.Sizer sizer)
```
    This is a pull through operation that guarantees to ATOMICALLY create a CacheCollector under the name if its not present OR return the previously created one if its there.
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    
    Parameters:
    
    name - the name of the CacheCounter to pull
    
    sizer - the CacheCollector.Sizer to use that can work out the size of the cache
    
    Returns:
    
    a NON NULL CacheCounter guaranteed
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a CacheCounter
  - pullCacheCollector
```
CacheCollector pullCacheCollector(String name)
```
    This is a pull through operation that guarantees to ATOMICALLY create a CacheCounter under the name if its not present OR return the previously created one if its there.
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    
    Parameters:
    
    name - the name of the CacheCounter to pull
    
    Returns:
    
    a NON NULL CacheCounter guaranteed
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a CacheCounter
  - pullCacheCounter
```
CacheCounter pullCacheCounter(String name,
                              CacheCounter.Sizer sizer)
```
    This is a pull through operation that guarantees to ATOMICALLY create a CacheCounter under the name if its not present OR return the previously created one if its there.
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    
    Parameters:
    
    name - the name of the CacheCounter to pull
    
    sizer - the CacheCounter.Sizer to use that can work out the size of the cache
    
    Returns:
    
    a NON NULL CacheCounter guaranteed
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a CacheCounter
  - pullCacheCounter
```
CacheCounter pullCacheCounter(String name)
```
    This is a pull through operation that guarantees to ATOMICALLY create a CacheCounter under the name if its not present OR return the previously created one if its there.
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    
    Parameters:
    
    name - the name of the CacheCounter to pull
    
    Returns:
    
    a NON NULL CacheCounter guaranteed
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a CacheCounter
  - pullOpCounter
```
OpCounter pullOpCounter(String name)
```
    This is a pull through operation that guarantees to ATOMICALLY create an OpCounter under the name if its not present OR return the previously created one if its there.
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    
    Parameters:
    
    name - the name of the OpCounter to pull
    
    Returns:
    
    a NON NULL OpCounter guaranteed
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a OpCounter
  - pullTimer
```
OpTimer pullTimer(String name)
```
    This is a pull through operation that guarantees to ATOMICALLY create a OpCounter under the name if its not present OR use the previously created one if its there. When OpTimer.end() is called, the value of the timer will be placed inside the named OpCounter.
    You code can use it something like this
```
  OpTimer timer = registry.pullOpTimer("some.operation");
  try {
      ..
      .. do some operation
      ..
  } finally {
    opTimer.end()
    // and OpCounter will now exist
    OpCounter opCounter = (OpCounter) registry.getInstrument("some.operation");
  }
 
```
    THREAD-SAFE - Uses ConcurrentHashMap under the covers
    Parameters:
    
    name - the name of the OpTimer to pull
    
    Returns:
    
    a NON NULL OpTimer guaranteed that is ready and RUNNING. Run Forrest Run!
    
    Throws:
    
    IllegalArgumentException - if there is already a named Instrument in the registry but is not a OpCounter
  - snapshotInstruments
```
List<Instrument> snapshotInstruments()
```
    This returns a snapshot list of Instrument objects in the InstrumentRegistry at the time the method was called.
    The list is MUTABLE and a copy of the underlying values. So feel free to mutate it by sorting it and filtering it.
    
    Returns:
    
    a mutable List of Instrument objects
  - getNumberOfInstruments
```
int getNumberOfInstruments()
```
    Returns the number of instruments that exist. Equivalent to calling snapshotInstruments().size() but more efficient.
    
    Returns:
    
    the number of instruments that exist at the time of the call.

Interface InstrumentRegistry

Method Summary

Method Detail

getRegistryConfiguration

putInstrument

getInstrument

pullAbsoluteCounter

pullCounter

pullDerivedCounter

pullGauge

pullCacheCollector

pullCacheCollector

pullCacheCounter

pullCacheCounter

pullOpCounter

pullTimer

snapshotInstruments

getNumberOfInstruments