FieldIDMapper

java.lang.Object
- edu.unh.sdb.common.FieldIDMapper

```
public class FieldIDMapper
extends java.lang.Object
```
This class records an array of field numbers from a component DataSource of a composite DataSource and a corresponding array of field numbers from that composite DataSource. It is meant to be used in the methods datum() and subblock() to facilitate the datum retrieval.

Field Summary

Fields
Modifier and Type	Field and Description
`protected int[]`	`componentFields` The field numbers from a component DataSource.
`protected int[]`	`compositeFields` The one-to-one corresponding field numbers from the composite DataSource.

Constructor Summary

Constructors
Constructor and Description
`FieldIDMapper(FieldIDMapper fm, RecordSpec cpsSpec)` Constructs a FieldIDMapper from a subset of given FieldIDMapper.
`FieldIDMapper(int numFields)` Constructs an identity FieldIDMapper of specified size.
`FieldIDMapper(int[] source)` Constructs a FieldIDMapper from a simple array of ints.
`FieldIDMapper(int[] componentFIDs, int[] compositeFIDs)` Constructs a FieldIDMapper with two parallel arrays.
`FieldIDMapper(RecordSpec recSpec)` Constructs a FieldIDMapper from a RecordSpec which specifies the attributes from a DataSource.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`checkComponentID()` Check whether the numbers in this.componentFields are distinct.
`void`	`checkCompositeID()` Check whether the numbers in this.compositeFields are distinct.
`java.lang.Object`	`clone()` Return a copy of this FieldIDMapper object
`FieldIDMapper`	`combine(FieldIDMapper fmap1, FieldIDMapper fmap2)` Put two FieldIDMappers together.
`static FieldIDMapper`	`createComponentMap(FieldIDMapper src, FieldIDMapper dst)` Constructs a FieldIDMapper by composing two related FieldIDMappers.
`static FieldIDMapper`	`createCrossMap(FieldIDMapper src, FieldIDMapper dst)` Constructs a FieldIDMapper by composing two related FieldIDMappers.
`boolean`	`equals(java.lang.Object obj)` Return true if parameter equals this object, false otherwise.
`int[]`	`getComponentFields()` Returns the field numbers of the component DataSource.
`int[]`	`getCompositeFields()` Returns the field numbers of the composite DataSource.
`int[]`	`getDestinations()` Returns the field numbers of the composite DataSource.
`int`	`getMaxCpnID()` Returns the maximum field number of this.componentFields.
`int`	`getMaxCpsID()` Returns the maximum field number of this.compositeFields.
`int[]`	`getSources()` Returns the source identifier array This is the same as getComponentFields(), but FieldIDMapper need not be restricted to Component/Composite mapping
`protected static void`	`identity(int[] array)` Assign identity mapping to the argument array "identity" mapping: 0,1, ...
`protected static int[]`	`identityArray(int len)` Create a integer array of specified length, initialized to the "identity" mapping: 0,1, ...
`boolean`	`isIdentityMapper()` Returns true if it is an identity FieldIDMapper.
`static void`	`main(java.lang.String[] args)`
`int`	`size()` Returns the number of fields.
`int`	`toComponent(int compositeIndex)` return the component index given a composite index.
`RecordSpec`	`toComponent(RecordSpec spec1)` Returns a RecordSpec mapped to the given RecordSpec whose field numbers could be found in this.compositeFields.
`int`	`toComposite(int componentIndex)` Returns the composite index given the component index.
`int`	`toDestination(int sourceIndex)` Returns the destination index given the source index.
`int`	`toSource(int destinationIndex)` return the source index given a destination index.
`java.lang.String`	`toString()` to String

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

- Field Detail
  - componentFields
```
protected int[] componentFields
```
    The field numbers from a component DataSource. The numbers are sorted in ascending order. The numbers should be distinct. Also can be thought of as the "source" of the mapping.
  - compositeFields
```
protected int[] compositeFields
```
    The one-to-one corresponding field numbers from the composite DataSource. The numbers should be distinct. Also can be thought of as the "destination" of the mapping.
- Constructor Detail
  - FieldIDMapper
```
public FieldIDMapper(int[] componentFIDs,
             int[] compositeFIDs)
```
    Constructs a FieldIDMapper with two parallel arrays. component -> composite source -> destination
  - FieldIDMapper
```
public FieldIDMapper(int numFields)
```
    Constructs an identity FieldIDMapper of specified size.
  - FieldIDMapper
```
public FieldIDMapper(RecordSpec recSpec)
```
    Constructs a FieldIDMapper from a RecordSpec which specifies the attributes from a DataSource. The RecordSpec entries become the "source" or component fields; the destination (composite fields) is the "identity" mapping: 0, 1, 2, ... This.compositeFields records the index positions of the field numbers in the RecordSpec argument.
  - FieldIDMapper
```
public FieldIDMapper(int[] source)
```
    Constructs a FieldIDMapper from a simple array of ints. the int array is the source (components). the destination (composite fields) is the "identity" mapping: 0, 1, 2, ... This.compositeFields records the index positions of the field numbers in the RecordSpec argument.
  - FieldIDMapper
```
public FieldIDMapper(FieldIDMapper fm,
             RecordSpec cpsSpec)
```
    Constructs a FieldIDMapper from a subset of given FieldIDMapper. The given RecordSpec specifies a subset of compositeFields (source) of the given FieldIDMapper.
- Method Detail
  - createCrossMap
```
public static FieldIDMapper createCrossMap(FieldIDMapper src,
                           FieldIDMapper dst)
```
    Constructs a FieldIDMapper by composing two related FieldIDMappers. The mapping is between fm1.compositeFields and fm2.componentFields. Useful for AttributeJoinDataSource.
  - createComponentMap
```
public static FieldIDMapper createComponentMap(FieldIDMapper src,
                               FieldIDMapper dst)
```
    Constructs a FieldIDMapper by composing two related FieldIDMappers. The mapping is between src.componentFields and dst.componentFields. Useful for BlockedDataSource.
  - identityArray
```
protected static final int[] identityArray(int len)
```
    Create a integer array of specified length, initialized to the "identity" mapping: 0,1, ...
  - identity
```
protected static final void identity(int[] array)
```
    Assign identity mapping to the argument array "identity" mapping: 0,1, ...
  - clone
```
public java.lang.Object clone()
```
    Return a copy of this FieldIDMapper object
    
    Overrides:
    
    clone in class java.lang.Object
  - combine
```
public FieldIDMapper combine(FieldIDMapper fmap1,
                    FieldIDMapper fmap2)
```
    Put two FieldIDMappers together.
  - isIdentityMapper
```
public boolean isIdentityMapper()
```
    Returns true if it is an identity FieldIDMapper.
  - getComponentFields
```
public int[] getComponentFields()
```
    Returns the field numbers of the component DataSource.
  - getCompositeFields
```
public int[] getCompositeFields()
```
    Returns the field numbers of the composite DataSource.
  - getSources
```
public int[] getSources()
```
    Returns the source identifier array This is the same as getComponentFields(), but FieldIDMapper need not be restricted to Component/Composite mapping
  - getDestinations
```
public int[] getDestinations()
```
    Returns the field numbers of the composite DataSource. This is the same as getCompositeFields(), but FieldIDMapper need not be restricted to Component/Composite mapping
  - getMaxCpnID
```
public int getMaxCpnID()
```
    Returns the maximum field number of this.componentFields.
  - getMaxCpsID
```
public int getMaxCpsID()
```
    Returns the maximum field number of this.compositeFields.
  - size
```
public int size()
```
    Returns the number of fields.
  - toComponent
```
public int toComponent(int compositeIndex)
```
    return the component index given a composite index.
  - toComposite
```
public int toComposite(int componentIndex)
```
    Returns the composite index given the component index.
  - toSource
```
public final int toSource(int destinationIndex)
```
    return the source index given a destination index. Identical to toComponent( int ).
  - toDestination
```
public final int toDestination(int sourceIndex)
```
    Returns the destination index given the source index. Identical to toComposite( int )
  - toComponent
```
public RecordSpec toComponent(RecordSpec spec1)
```
    Returns a RecordSpec mapped to the given RecordSpec whose field numbers could be found in this.compositeFields. It is useful for BlockedDataSource since the components and the composite DataSource have the same attributes.
  - equals
```
public boolean equals(java.lang.Object obj)
```
    Return true if parameter equals this object, false otherwise.
    
    Overrides:
    
    equals in class java.lang.Object
  - checkComponentID
```
public void checkComponentID()
```
    Check whether the numbers in this.componentFields are distinct.
  - checkCompositeID
```
public void checkCompositeID()
```
    Check whether the numbers in this.compositeFields are distinct.
  - toString
```
public java.lang.String toString()
```
    to String
    
    Overrides:
    
    toString in class java.lang.Object
  - main
```
public static void main(java.lang.String[] args)
```

Class FieldIDMapper

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

componentFields

compositeFields

Constructor Detail

FieldIDMapper

FieldIDMapper

FieldIDMapper

FieldIDMapper

FieldIDMapper

Method Detail

createCrossMap

createComponentMap

identityArray

identity

clone

combine

isIdentityMapper

getComponentFields

getCompositeFields

getSources

getDestinations

getMaxCpnID

getMaxCpsID

size

toComponent

toComposite

toSource

toDestination

toComponent

equals

checkComponentID

checkCompositeID

toString

main