StatGroup (starrocks-bdb-je 18.3.17 API)

java.lang.Object
- com.sleepycat.je.utilint.StatGroup

All Implemented Interfaces:

Serializable
```
public class StatGroup
extends Object
implements Serializable
```
The Stats infrastructure provides context for JE statistics. Each statistic has these attributes: - metadata - specifically, a name and description - each statistic is associated with a parent stat group, which itself has a name and description. - support for the StatsConfig.clear semantics - a way to print statistics in a user friendly way. To create a statistic variable, instantiate one of the concrete subclasses of Stat. Each concrete subclass should hold the methods that are needed to best set and display the value. For example, instead of using LongStat to hold a timestamp or LSN value, use TimestampStat or LSNStat. A Stat instance needs to specify a StatDefinition. There may be multiple Stat variables in different components that share a StatDefinition. They are differentiated when displayed by their parent StatGroup. Each Stat instance is associated with a StatGroup, which holds the collection of stats that belong to a given component. Each member of the StatGroup has a unique StatDefinition. StatGroups can be combined, in order to accumulate values. For example, the LockManager may have multiple lock tables. Each lock table keeps its own latch statistics. When LockStats are generated, the StatsGroup for each latch is collected and rolled up into a single StatGroup, using the addAll(StatGroup) method. The Stats infrastructure is for internal use only. Public API classes like EnvironmentStats, LockStats, etc, contain StatGroups. A call to retrieve stats is implemented by getting a clone of the StatGroups held by the components like the cleaner, the incompressor, the LockManager, etc. The public API classes provide getter methods that reach into the StatGroups to return the specific stat value. To add a statistic, create the Stat variable in the component where it is being used and associate it with a StatGroup. The Stat infrastructure does the rest of the work for plumbing that statistic up to the public API class. Each API class must provide a getter method to access the specific statistic. Currently, this is done manually.

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description

StatGroup(String groupName, String groupDescription)

Constructors
Constructor and Description
`StatGroup(String groupName, String groupDescription)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addAll(StatGroup other)` Add all the stats from the other group into this group.
`void`	`addToTipMap(Map<String,String> tips)`
`void`	`clear()` Clear all stats in a StatGroup.
`StatGroup`	`cloneGroup(boolean clear)`
`StatGroup`	`computeInterval(StatGroup baseGroup)` The caller must make sure that no stats are added to or removed from this stat group while this method is being called.
`TransactionStats.Active[]`	`getActiveTxnArray(StatDefinition definition)`
`Long`	`getAtomicLong(StatDefinition definition)`
`AtomicLongStat`	`getAtomicLongStat(StatDefinition definition)`
`boolean`	`getBoolean(StatDefinition definition)`
`String`	`getCSVData()` Return a string suitable for using as the data for a .csv file.
`String`	`getCSVHeader()` Return a string suitable for using as the header for a .csv file.
`String`	`getDescription()`
`float`	`getFloat(StatDefinition definition)`
`int`	`getInt(StatDefinition definition)`
`IntegralLongAvgStat`	`getIntegralLongAvgStat(StatDefinition definition)`
`long`	`getLong(StatDefinition definition)`
`long[]`	`getLongArray(StatDefinition definition)`
`LongMaxStat`	`getLongMaxStat(StatDefinition definition)`
`LongMinStat`	`getLongMinStat(StatDefinition definition)`
`LongStat`	`getLongStat(StatDefinition definition)`
`<V> SortedMap<String,V>`	`getMap(StatDefinition definition)`
`String`	`getName()`
`Stat<?>`	`getStat(StatDefinition definition)` Return the stat associated with the specified definition, or null if not found.
`Map<StatDefinition,Stat<?>>`	`getStats()` Returns a synchronized, unmodifiable view of the stats in this group.
`String`	`getString(StatDefinition definition)`
`void`	`negate()` Negates all stats in a StatGroup.
`String`	`toString()`
`String`	`toStringConcise()` Only print values that are not null or zero.
`String`	`toStringVerbose()` Includes the per-stat description in the output string.

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

Constructor Detail

StatGroup

public StatGroup(String groupName,
                 String groupDescription)

Method Detail
- getStats
```
public Map<StatDefinition,Stat<?>> getStats()
```
  Returns a synchronized, unmodifiable view of the stats in this group. Note that the returned set can still be modified by other threads, so the caller needs to take that into account.
- addAll
```
public void addAll(StatGroup other)
```
  Add all the stats from the other group into this group. If both groups have the same stat, add the values. The caller must make sure that no stats are added to or removed from the argument during this call.
  
  Throws:
  
  ConcurrentModificationException - if the addition or removal of stats in the argument is detected
- computeInterval
```
public StatGroup computeInterval(StatGroup baseGroup)
```
  The caller must make sure that no stats are added to or removed from this stat group while this method is being called.
  
  Throws:
  
  ConcurrentModificationException - if the addition or removal of stats in this group is detected
- clear
```
public void clear()
```
  Clear all stats in a StatGroup.
- negate
```
public void negate()
```
  Negates all stats in a StatGroup.
- getName
```
public String getName()
```
- getDescription
```
public String getDescription()
```
- cloneGroup
```
public StatGroup cloneGroup(boolean clear)
```
  Returns:
  
  a Stats class that copies the value of all stats in the group
- getStat
```
public Stat<?> getStat(StatDefinition definition)
```
  Return the stat associated with the specified definition, or null if not found.
  
  Returns:
  
  the stat or null
- getInt
```
public int getInt(StatDefinition definition)
```
- getLongStat
```
public LongStat getLongStat(StatDefinition definition)
```
- getLong
```
public long getLong(StatDefinition definition)
```
- getIntegralLongAvgStat
```
public IntegralLongAvgStat getIntegralLongAvgStat(StatDefinition definition)
```
- getLongMinStat
```
public LongMinStat getLongMinStat(StatDefinition definition)
```
- getLongMaxStat
```
public LongMaxStat getLongMaxStat(StatDefinition definition)
```
- getAtomicLongStat
```
public AtomicLongStat getAtomicLongStat(StatDefinition definition)
```
- getAtomicLong
```
public Long getAtomicLong(StatDefinition definition)
```
- getActiveTxnArray
```
public TransactionStats.Active[] getActiveTxnArray(StatDefinition definition)
```
- getLongArray
```
public long[] getLongArray(StatDefinition definition)
```
- getFloat
```
public float getFloat(StatDefinition definition)
```
- getBoolean
```
public boolean getBoolean(StatDefinition definition)
```
- getString
```
public String getString(StatDefinition definition)
```
- getMap
```
public <V> SortedMap<String,V> getMap(StatDefinition definition)
```
- addToTipMap
```
public void addToTipMap(Map<String,String> tips)
```
- toString
```
public String toString()
```
  Overrides:
  
  toString in class Object
- toStringVerbose
```
public String toStringVerbose()
```
  Includes the per-stat description in the output string.
- toStringConcise
```
public String toStringConcise()
```
  Only print values that are not null or zero.
- getCSVHeader
```
public String getCSVHeader()
```
  Return a string suitable for using as the header for a .csv file.
- getCSVData
```
public String getCSVData()
```
  Return a string suitable for using as the data for a .csv file.

Class StatGroup

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

StatGroup

Method Detail

getStats

addAll

computeInterval

clear

negate

getName

getDescription

cloneGroup

getStat

getInt

getLongStat

getLong

getIntegralLongAvgStat

getLongMinStat

getLongMaxStat

getAtomicLongStat

getAtomicLong

getActiveTxnArray

getLongArray

getFloat

getBoolean

getString

getMap

addToTipMap

toString

toStringVerbose

toStringConcise

getCSVHeader

getCSVData