Interface TestTimesInterface

public interface TestTimesInterface

This interface will be used to organize and manage test times that are measured for specific operations. Implementing this interface requires the following:

• The implementation is required to save the last 10 time measurements. If the user adds exactly 10 measurements, the implementation will keep all 10. If the user adds n, where n > 10, the implementation will keep the last 10 measurements.
• If you have made no measurements, your array will contain the following: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0].
• If you have made 5 measurements m_n, your array will contain the following: [m₁, m₂, m₃, m₄, m₅, 0, 0, 0, 0, 0].
• If you have made 10 measurements m_n, your array will contain the following: [m₁, m₂, m₃, m₄, m₅, m₆, m₇, m₈, m₉, m₁₀].
• If you have made 13 measurements m_n, your array will contain the following: [m₄, m₅, m₆, m₇, m₈, m₉, m₁₀, m₁₁, m₁₂, m₁₃].
• Please pay attention to the ordering of the measurements described above.
• The implementation is required to compute average calculations using only added measurements.
• If the user has added only 3 measurements m_n, then the average is (m₁ + m₂ + m₃)/3.
• If the user has added 10 measurements, then the average is (m₁ + m₂ + m₃ + m₄ + m₅ + m₆ + m₇ + m₈ + m₉ + m₁₀)/10.
• If the user has added n measurement, where n > 10, then the average is (m_n-9 + m_n-8 + m_n-7 + m_n-6 + m_n-5 + m_n-4 + m_n-3 + m_n-2 + m_n-1 + m_n)/10.
• The implementation will represent all nanosecond time measurements as long values.
• The implementation will compute averages and represent them as double values.

Users of an implementation of this interface calculate time measurements as follows:

• Before the operation is started, you can obtain the start time:
  long startTime = System.nanoTime().
• After the operation is completed, you can obtain the end time:
  long endTime = System.nanoTime().
• Test Time can then be computed:
  long testTime = endTime - startTime.

Author:

Sameh A. Fakhouri

Method Summary

Modifier and Type	Method and Description
void	addTestTime(long testTime) This method is used to add a test time.
double	getAverageTestTime() This method is used to obtain the average test time.
long	getLastTestTime() This method is used to retrieve the last test time.
long[]	getTestTimes() This method returns an array of long values representing the last 10 test times.
void	resetTestTimes() This method is used to reset all 10 linear search times to zero.

Method Detail

getLastTestTime

long getLastTestTime()

This method is used to retrieve the last test time. If no test time has been added, the method will return a zero.

Returns:

The last test time, in nanoseconds, or zero.

getTestTimes

long[] getTestTimes()

This method returns an array of long values representing the last 10 test times. If less than 10 test times are available, the remaining test times should be zero. If more than 10 test times have been added, the array should contain the last 10 test times.

Returns:

An array of long values representing the last 10 test times.

resetTestTimes

void resetTestTimes()

This method is used to reset all 10 linear search times to zero.

addTestTime

void addTestTime(long testTime)

This method is used to add a test time. If more than 10 test times get added, this method will keep the last 10 test times.

Parameters:

testTime - a long value representing the test time in nanoseconds.

getAverageTestTime

double getAverageTestTime()

This method is used to obtain the average test time. The method should average all the non-zero test times that are available. If no test times are available, the method returns a zero.

Returns:

A double value representing the average of all the non-zero test times, or zero.