Package org.apache.iotdb.udf.api.access

Interface RowWindow

public interface RowWindow

Method Summary

Modifier and Type	Method	Description
Type	getDataType(int columnIndex)	Returns the actual data type of the values at the specified column in this window.
Row	getRow(int rowIndex)	Returns the row at the specified position in this window.
RowIterator	getRowIterator()	Returns an iterator used to access this window.
long	windowEndTime()	For different types of windows, the definition of the window end time is different.
int	windowSize()	Returns the number of rows in this window.
long	windowStartTime()	For different types of windows, the definition of the window start time is different.

Method Detail

windowSize

int windowSize()

Returns the number of rows in this window.

Returns:

the number of rows in this window

getRow

Row getRow(int rowIndex)
    throws java.io.IOException

Returns the row at the specified position in this window.

Note that the Row instance returned by this method each time is the same instance. In other words, calling this method will only change the member variables inside the Row instance, but will not generate a new Row instance.

Parameters:

rowIndex - index of the row to return

Returns:

the row at the specified position in this window, throw IndexOutOfBoundException if call this method on an empty RowWindow.

Throws:

java.io.IOException - if any I/O errors occur

getDataType

Type getDataType(int columnIndex)

Returns the actual data type of the values at the specified column in this window.

Parameters:

columnIndex - index of the specified column

Returns:

the actual data type of the values at the specified column in this window

getRowIterator

RowIterator getRowIterator()

Returns an iterator used to access this window.

Returns:

an iterator used to access this window

windowStartTime

long windowStartTime()

For different types of windows, the definition of the window start time is different.

For sliding size window: the window start time is equal to the timestamp of the first row.

For sliding time window: The window start time is determined by displayWindowBegin SlidingTimeWindowAccessStrategy.getDisplayWindowBegin() and slidingStep SlidingTimeWindowAccessStrategy.getSlidingStep().
The window start time for the i-th window (i starts at 0) can be calculated as displayWindowBegin + i * slidingStep.

Returns:

the start time of the window

Since:

0.13.0

See Also:

SlidingSizeWindowAccessStrategy, SlidingTimeWindowAccessStrategy

windowEndTime

long windowEndTime()

For different types of windows, the definition of the window end time is different.

For sliding size window: the window end time is equal to the timestamp of the last row.

For sliding time window: The window end time is determined by displayWindowBegin SlidingTimeWindowAccessStrategy.getDisplayWindowBegin(), timeInterval SlidingTimeWindowAccessStrategy.getTimeInterval() and slidingStep SlidingTimeWindowAccessStrategy.getSlidingStep().
The window end time for the i-th window (i starts at 0) can be calculated as displayWindowBegin + i * slidingStep + timeInterval - 1 or windowStartTime(i) + timeInterval - 1.

Returns:

the end time of the window

Since:

0.13.0

See Also:

SlidingSizeWindowAccessStrategy, SlidingTimeWindowAccessStrategy