FrameComparisonWidget (druid-processing 28.0.0 API)

All Known Implementing Classes:

FrameComparisonWidgetImpl
```
public interface FrameComparisonWidget
```
Wraps a Frame and provides ways to compare rows of that frame to various other things. Not thread-safe.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`int`	`compare(int row, FrameComparisonWidget otherWidget, int otherRow)`	Compare a specific row of this frame to a specific row of another frame.
`int`	`compare(int row, RowKey key)`	Compare a specific row of this frame to the provided key.
`boolean`	`isCompletelyNonNullKey(int row)`	Whether a particular row has no null fields in its comparison key.
`RowKey`	`readKey(int row)`	Returns the `RowKey` corresponding to a particular row.

- Method Detail
  - readKey
```
RowKey readKey(int row)
```
    Returns the RowKey corresponding to a particular row. The returned key is a copy that does not reference memory of the underlying Frame.
  - isCompletelyNonNullKey
```
boolean isCompletelyNonNullKey(int row)
```
    Whether a particular row has no null fields in its comparison key. When NullHandling.replaceWithDefault(), default values (like empty strings and numeric zeroes) are considered null for purposes of this method. This behavior is inherited from FieldReader.isNull(Memory, long) and enables join code to behave similarly in MSQ and native queries.
  - compare
```
int compare(int row,
            RowKey key)
```
    Compare a specific row of this frame to the provided key. The key must have been created with sortColumns that match the ones used to create this widget, or else results are undefined.
  - compare
```
int compare(int row,
            FrameComparisonWidget otherWidget,
            int otherRow)
```
    Compare a specific row of this frame to a specific row of another frame. The other frame must have the same sort key, or else results are undefined. The other frame may be the same object as this frame; for example, this is used by FrameSort to sort frames in-place.