public void TrieSuggestorService_WhenEmptyStringPassed_ShouldReturnAllStations()
{
// Arrange
var content = new List <string> {
"A", "AA", "AB", "AC", "AD"
};
fileHandler.Setup(fh => fh.ReadTextFileLines()).Returns(content);
this.service = new TrieSuggestorService(fileHandler.Object);
List <string> expectedStations = new List <string> {
"A", "AA", "AB", "AC", "AD"
};
// Act
var result = this.service.GetSuggestions("");
// Assert
Assert.AreEqual(result.Stations.Count, 5);
foreach (string expectedStation in expectedStations)
{
Assert.Contains(expectedStation, result.Stations);
}
}
public void TrieSuggestorService_WhenDataFileExists_ShouldReturnSuggestions(string input)
{
// Arrange
var content = new List <string> {
"AQ",
};
fileHandler.Setup(fh => fh.ReadTextFileLines()).Returns(content);
this.service = new TrieSuggestorService(fileHandler.Object);
// Act
var result = this.service.GetSuggestions(input);
// Assert
Assert.IsNotNull(result);
}
public void TrieSuggestorService_WhenFurtherStationsWithUserInputPrefixDoesNotExist_ShouldNotReturnNextLetters()
{
// Arrange
var content = new List <string> {
"A", "AA", "AB", "AC", "AAA", "AAC", "ABB", "B", "BA"
};
fileHandler.Setup(fh => fh.ReadTextFileLines()).Returns(content);
this.service = new TrieSuggestorService(fileHandler.Object);
List <char> expectedNextLetters = new List <char> {
};
// Act
var result = this.service.GetSuggestions("aaa");
// Assert
Assert.AreEqual(expectedNextLetters.Count, result.NextLetters.Count);
Assert.AreEqual(result.NextLetters.Count, 0);
}
public void TrieSuggestorService_WhenStationsWithUserInputPrefixExist_ShouldReturnTheCorrectStations(string input, string[] expected)
{
// Arrange
var content = new List <string> {
"A", "AA", "AB", "AC", "AAA", "AAC", "ABB", "B", "BA"
};
fileHandler.Setup(fh => fh.ReadTextFileLines()).Returns(content);
this.service = new TrieSuggestorService(fileHandler.Object);
List <string> expectedStations = expected.ToList();
// Act
var result = this.service.GetSuggestions(input);
// Assert
Assert.AreEqual(expectedStations.Count, result.Stations.Count);
foreach (string expectedStation in expectedStations)
{
Assert.Contains(expectedStation, result.Stations);
}
}
static void Main(string[] args)
{
ITrainStationSuggestorService suggestorWithTrie;
IFileHandler fileHAndler = new FileHandler("Data\\TrainStations.txt");
try
{
// Init suggestors
suggestorWithTrie = new TrieSuggestorService(fileHAndler);
// Tests the suggestor implementation with user input
TestSuggestor(ref suggestorWithTrie);
// Meassures and displays performance difference between Trie and List implementation
// ListSuggestorService uses List and Linq, Trie uses Trie search tree data structure
CheckPerformance();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Console.Read();
}
/// <summary>
/// Page faults, static initializers, JIT, CPU cache, branch predictors, and context switches affect run time
/// therefore performance is checked in initiaising multiple times, and seach performance checked by searching
/// for multiple (randomly generated) user inputs
/// </summary>
public static void CheckPerformance()
{
Console.WriteLine("");
Console.WriteLine("#############################################");
Console.WriteLine("-- Trainstation suggester performance test --");
Console.WriteLine("#############################################");
Console.WriteLine("");
Stopwatch stopwatch = new Stopwatch();
IFileHandler fileHandler = new FileHandler("Data\\TrainStations.txt");
ITrainStationSuggestorService trieService;
ITrainStationSuggestorService listService;
trieService = new TrieSuggestorService(fileHandler);
listService = new ListSuggestorService(fileHandler);
// Performance check for initialisation (building the stations lists
int numOfInit = 100;
stopwatch.Start();
for (int i = 0; i < numOfInit; ++i)
{
trieService = new TrieSuggestorService(fileHandler);
}
stopwatch.Start();
var trieInitPerf = stopwatch.ElapsedTicks / numOfInit;
stopwatch.Reset();
stopwatch.Start();
for (int i = 0; i < 100; ++i)
{
listService = new ListSuggestorService(fileHandler);
}
stopwatch.Start();
var listInitPerf = stopwatch.ElapsedTicks / numOfInit;
stopwatch.Reset();
Console.WriteLine("---------------------------------------------------");
Console.WriteLine($"Trie initialisation average performance: { trieInitPerf } ticks.");
Console.WriteLine($"List initialisation average performance: { listInitPerf } ticks.");
Console.WriteLine("---------------------------------------------------");
Console.WriteLine("Generating test user inputs for search performance test...");
// Performance check for search
Suggestions result;
Random random = new Random();
int numOfTestInput = 50;
var userInputs = fileHandler.GetRandomStationPrefixes(numOfTestInput);
Console.Write("Generated inputs: ");
foreach (string input in userInputs)
{
Console.Write($"{input} ");
}
Console.WriteLine("");
stopwatch.Start();
foreach (string input in userInputs)
{
result = trieService.GetSuggestions(input);
}
stopwatch.Stop();
var trieSearchPerf = stopwatch.ElapsedTicks / numOfTestInput;
stopwatch.Reset();
stopwatch.Start();
foreach (string input in userInputs)
{
result = listService.GetSuggestions(input);
}
stopwatch.Stop();
var listSearchPerf = stopwatch.ElapsedTicks / numOfTestInput;
stopwatch.Reset();
Console.WriteLine("---------------------------------------------------");
Console.WriteLine($"Trie search average performance: { trieSearchPerf } ticks.");
Console.WriteLine($"List search average performance: { listSearchPerf } ticks.");
}
