DocumentalPartitioningStrategy (MG4J (big) 5.4.4)

All Superinterfaces:

PartitioningStrategy, Serializable

All Known Implementing Classes:

ContiguousDocumentalStrategy
```
public interface DocumentalPartitioningStrategy
extends PartitioningStrategy
```
A way to associate a document with a local index out of a given set and a local document number in the local index.
When partitioning documentally an index, we need a way to associate to each global document pointer a local index (the index that will contain the postings of that document) and a local document pointer (the document pointer actually represented in the local index).
Usually, a documental partitioning strategy has a matching DocumentalClusteringStrategy whose methods satisfy the following equations:
```
 globalPointer(localIndex(d), localPointer(d)) = d
 <localIndex(globalPointer(i, l)), localPointer(globalPointer(i, l))> = <i, l>
 
```
Author:

Alessandro Arrabito, Sebastiano Vigna

Method Summary

Modifier and Type	Method	Description
`int`	`localIndex(long globalPointer)`	Returns the index to which a given global document pointer is be mapped by this strategy.
`long`	`localPointer(long globalPointer)`	Returns the local document pointer corresponding to a global document pointer.
`long`	`numberOfDocuments(int localIndex)`	Returns the number of documents that will be assigned to the given local index.

Methods inherited from interface it.unimi.di.big.mg4j.index.cluster.PartitioningStrategy
numberOfLocalIndices, properties

- Method Detail
  - localIndex
```
int localIndex(long globalPointer)
```
    Returns the index to which a given global document pointer is be mapped by this strategy.
    
    Parameters:
    
    globalPointer - a global document pointer.
    
    Returns:
    
    the corresponding local index.
  - localPointer
```
long localPointer(long globalPointer)
```
    Returns the local document pointer corresponding to a global document pointer.
    
    Parameters:
    
    globalPointer - a global document pointer.
    
    Returns:
    
    the corresponding local document pointer.
  - numberOfDocuments
```
long numberOfDocuments(int localIndex)
```
    Returns the number of documents that will be assigned to the given local index.
    
    Parameters:
    
    localIndex - the local index.
    
    Returns:
    
    the number of documents that will be assigned to localIndex.