com.idevicesinc.sweetblue.utils

Interface HistoricalDataCursor

public interface HistoricalDataCursor

This interface defines a wrapper around a database cursor (similar to Cursor) specific to a database representing a series of HistoricalData serializations. For performance reasons, implementations are not required to return actual HistoricalData instances, just the underlying byte[] BLOB and long timestamp for each.

NOTE: This may be wrapping an in-memory list, not just a database.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the Cursor, releasing all of its resources and making it completely invalid.
byte[]	getBlob() Returns the BLOB of the historical data as a byte[], equivalent to HistoricalData.getBlob() but a raw byte[] is used for performance reasons.
int	getCount() Returns the numbers of rows in the cursor.
long	getEpochTime() Returns the epoch time of the historical data as a long, equivalent to HistoricalData.getEpochTime() but raw long is used for performance reasons.
HistoricalData	getHistoricalData() Returns the historical data at the current position.
int	getPosition() Returns the current position of the cursor in the row set.
boolean	isAfterLast() Returns whether the cursor is pointing to the position after the last row.
boolean	isBeforeFirst() Returns whether the cursor is pointing to the position before the first row.
boolean	isClosed() return true if the cursor is closed
boolean	isFirst() Returns whether the cursor is pointing to the first row.
boolean	isLast() Returns whether the cursor is pointing to the last row.
boolean	move(int offset) Move the cursor by a relative amount, forward or backward, from the current position.
boolean	moveToFirst() Move the cursor to the first row.
boolean	moveToLast() Move the cursor to the last row.
boolean	moveToNext() Move the cursor to the next row.
boolean	moveToPosition(int position) Move the cursor to an absolute position.
boolean	moveToPrevious() Move the cursor to the previous row.

Method Detail

getCount

int getCount()

Returns the numbers of rows in the cursor.

Returns:

the number of rows in the cursor.

getPosition

int getPosition()

Returns the current position of the cursor in the row set. The value is zero-based. When the row set is first returned the cursor will be at positon -1, which is before the first row. After the last row is returned another call to next() will leave the cursor past the last entry, at a position of count().

Returns:

the current cursor position.

move

boolean move(int offset)

Move the cursor by a relative amount, forward or backward, from the current position. Positive offsets move forwards, negative offsets move backwards. If the final position is outside of the bounds of the result set then the resultant position will be pinned to -1 or count() depending on whether the value is off the front or end of the set, respectively.

This method will return true if the requested destination was reachable, otherwise, it returns false. For example, if the cursor is at currently on the second entry in the result set and move(-5) is called, the position will be pinned at -1, and false will be returned.

Parameters:

offset - the offset to be applied from the current position.

Returns:

whether the requested move fully succeeded.

moveToPosition

boolean moveToPosition(int position)

Move the cursor to an absolute position. The valid range of values is -1 <= position <= count.

This method will return true if the request destination was reachable, otherwise, it returns false.

Parameters:

position - the zero-based position to move to.

Returns:

whether the requested move fully succeeded.

moveToFirst

boolean moveToFirst()

Move the cursor to the first row.

This method will return false if the cursor is empty.

Returns:

whether the move succeeded.

moveToLast

boolean moveToLast()

Move the cursor to the last row.

This method will return false if the cursor is empty.

Returns:

whether the move succeeded.

moveToNext

boolean moveToNext()

Move the cursor to the next row.

This method will return false if the cursor is already past the last entry in the result set.

Returns:

whether the move succeeded.

moveToPrevious

boolean moveToPrevious()

Move the cursor to the previous row.

This method will return false if the cursor is already before the first entry in the result set.

Returns:

whether the move succeeded.

isFirst

boolean isFirst()

Returns whether the cursor is pointing to the first row.

Returns:

whether the cursor is pointing at the first entry.

isLast

boolean isLast()

Returns whether the cursor is pointing to the last row.

Returns:

whether the cursor is pointing at the last entry.

isBeforeFirst

boolean isBeforeFirst()

Returns whether the cursor is pointing to the position before the first row.

Returns:

whether the cursor is before the first result.

isAfterLast

boolean isAfterLast()

Returns whether the cursor is pointing to the position after the last row.

Returns:

whether the cursor is after the last result.

close

void close()

Closes the Cursor, releasing all of its resources and making it completely invalid.

isClosed

boolean isClosed()

return true if the cursor is closed

Returns:

true if the cursor is closed.

getEpochTime

long getEpochTime()

Returns the epoch time of the historical data as a long, equivalent to HistoricalData.getEpochTime() but raw long is used for performance reasons.

getBlob

byte[] getBlob()

Returns the BLOB of the historical data as a byte[], equivalent to HistoricalData.getBlob() but a raw byte[] is used for performance reasons.

getHistoricalData

HistoricalData getHistoricalData()

Returns the historical data at the current position. Note that this may or may not allocate an instance on demand, which may be a minor but unneccessary performance hit for your use case. See also getEpochTime() and getBlob() to directly access the underlying data without boxing.