OptimizerFactory.HiLoOptimizer (Hibernate Core Aggregator 3.6.10.Final API)

java.lang.Object
- org.hibernate.id.enhanced.OptimizerFactory.OptimizerSupport
- - org.hibernate.id.enhanced.OptimizerFactory.HiLoOptimizer

All Implemented Interfaces:

Optimizer

Enclosing class:

OptimizerFactory
```
public static class OptimizerFactory.HiLoOptimizer
extends OptimizerFactory.OptimizerSupport
```
Optimizer which applies a 'hilo' algorithm in memory to achieve optimization.
A 'hilo' algorithm is simply a means for a single value stored in the database to represent a "bucket" of possible, contiguous values. The database value identifies which particular bucket we are on.
This database value must be paired with another value that defines the size of the bucket; the number of possible values available. The incrementSize serves this purpose. The naming here is meant more for consistency in that this value serves the same purpose as the increment supplied to the OptimizerFactory.PooledOptimizer.
The general algorithms used to determine the bucket are:
1. upperLimit = (databaseValue * incrementSize) + 1
2. lowerLimit = upperLimit - 1
As an example, consider a case with incrementSize of 10. Initially the database holds 1:
1. upperLimit = (1 * 20) + 1 = 21
2. lowerLimit = 21 - 20 = 1
From there we increment the value from lowerLimit until we reach the upperLimit, at which point we would define a new bucket. The database now contains 2, though incrementSize remains unchanged:
1. upperLimit = (2 * 20) + 1 = 41
2. lowerLimit = 41 - 20 = 21
And so on...
Note, 'value' always (after init) holds the next value to return

Field Summary
- Fields inherited from class org.hibernate.id.enhanced.OptimizerFactory.OptimizerSupport
  incrementSize, returnClass

Constructor Summary

Constructors
Constructor and Description

OptimizerFactory.HiLoOptimizer(Class returnClass, int incrementSize)

Constructors
Constructor and Description
`OptimizerFactory.HiLoOptimizer(Class returnClass, int incrementSize)`

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`applyIncrementSizeToSourceValues()` Are increments to be applied to the values stored in the underlying value source?
`Serializable`	`generate(AccessCallback callback)` Generate an identifier value accounting for this specific optimization.
`IntegralDataTypeHolder`	`getHiValue()` Getter for property 'upperLimit'.
`IntegralDataTypeHolder`	`getLastSourceValue()` A common means to access the last value obtained from the underlying source.
`IntegralDataTypeHolder`	`getLastValue()` Getter for property 'lastValue'.

Methods inherited from class org.hibernate.id.enhanced.OptimizerFactory.OptimizerSupport
getIncrementSize, getReturnClass

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

- Constructor Detail
  - OptimizerFactory.HiLoOptimizer
```
public OptimizerFactory.HiLoOptimizer(Class returnClass,
                              int incrementSize)
```
- Method Detail
  - generate
```
public Serializable generate(AccessCallback callback)
```
    Generate an identifier value accounting for this specific optimization.
    
    Parameters:
    callback - Callback to access the underlying value source.
    
    Returns:
    The generated identifier value.
  - getLastSourceValue
```
public IntegralDataTypeHolder getLastSourceValue()
```
    A common means to access the last value obtained from the underlying source. This is intended for testing purposes, since accessing the underlying database source directly is much more difficult.
    
    Returns:
    The last value we obtained from the underlying source; null indicates we have not yet consulted with the source.
  - applyIncrementSizeToSourceValues
```
public boolean applyIncrementSizeToSourceValues()
```
    Are increments to be applied to the values stored in the underlying value source?
    
    Returns:
    True if the values in the source are to be incremented according to the defined increment size; false otherwise, in which case the increment is totally an in memory construct.
  - getLastValue
```
public IntegralDataTypeHolder getLastValue()
```
    Getter for property 'lastValue'.
    Exposure intended for testing purposes.
    
    Returns:
    Value for property 'lastValue'.
  - getHiValue
```
public IntegralDataTypeHolder getHiValue()
```
    Getter for property 'upperLimit'.
    Exposure intended for testing purposes.
    
    Returns:
    Value for property 'upperLimit'.

Class OptimizerFactory.HiLoOptimizer

Field Summary

Fields inherited from class org.hibernate.id.enhanced.OptimizerFactory.OptimizerSupport

Constructor Summary

Method Summary

Methods inherited from class org.hibernate.id.enhanced.OptimizerFactory.OptimizerSupport

Methods inherited from class java.lang.Object

Constructor Detail

OptimizerFactory.HiLoOptimizer

Method Detail

generate

getLastSourceValue

applyIncrementSizeToSourceValues

getLastValue

getHiValue