PartitioningFunction (Dataflow Library Distribution Project 8.0.0-98 API)

All Known Implementing Classes:

HashPartitioningFunction, HBasePartitioningFunction, RangePartitioningFunction
```
public interface PartitioningFunction
```
Represents a pluggable partitioning function; for use by operators that require custom partitioning

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface PartitioningFunction.Evaluator
Computes partition assignments for each row if input

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`PartitioningFunction.Evaluator`	`getEvaluator(PartitioningFunctionContext ctx)`	Create an Evaluator bound to the specified context.
`boolean`	`isEquivalentPartitioning(PartitioningFunction other)`	Returns true iff, given a single row of input, this function is guaranteed to produce the same partitioning as the other function.
`boolean`	`isFunctionOfInput()`	Returns true iff, given two identical rows of input, this function will return the same value.
`PartitioningFunction`	`remapFieldReferences(Map<String,String> oldToNewMapping)`	Creates a new function, equivalent to the given function, but with all field references renamed according to the given mapping.
`void`	`validateForType(RecordTokenType type)`	Performs validation of the specified input type

- Method Detail
  - getEvaluator
```
PartitioningFunction.Evaluator getEvaluator(PartitioningFunctionContext ctx)
```
    Create an Evaluator bound to the specified context.
    
    Parameters:
    
    ctx - the partitioning context
    
    Returns:
    
    an Evaluator bound to the specified context.
  - validateForType
```
void validateForType(RecordTokenType type)
```
    Performs validation of the specified input type
    
    Parameters:
    
    type - the input type
  - isFunctionOfInput
```
boolean isFunctionOfInput()
```
    Returns true iff, given two identical rows of input, this function will return the same value. A return of true thus implies :
  - the function is deterministic
  - the function is stateless (not sensitive to previous values read or to input ordering)

Returns:: whether this function is a stateless, deterministic function of input

isEquivalentPartitioning
```
boolean isEquivalentPartitioning(PartitioningFunction other)
```
Returns true iff, given a single row of input, this function is guaranteed to produce the same partitioning as the other function. A return of true thus implies the following:
both functions are deterministic
both function are stateless (not sensitive to previous values read or to input ordering)

isFunctionOfInput()

isFunctionOfInput()

Parameters:: other - the other function
Returns:: whether this function produces the same results as the other function.

remapFieldReferences
```
PartitioningFunction remapFieldReferences(Map<String,String> oldToNewMapping)
```
Creates a new function, equivalent to the given function, but with all field references renamed according to the given mapping.

Parameters:

oldToNewMapping - a mapping from old names to new names. If a name is not present in the given mapping, it will remain as-is.

Returns:

a new function with all field reference renamed appropriately