public void MultipleEnumerations_ShouldEnumerateOnce()
{
var enumerable = new SingleEnumerable <int>(Enumerable.Range(1, 3));
var cachedEnumerable = CachedEnumerable.Create(enumerable);
Assert.Equal(new[] { 1, 2, 3 }, cachedEnumerable);
Assert.Equal(new[] { 1, 2, 3 }, cachedEnumerable);
}
public void MultipleConcurrentEnumerations_ShouldEnumerateOnce()
{
// Arrange
var count = 0;
var cachedEnumerable = CachedEnumerable.Create(new SingleEnumerable <int>(GetData()));
IEnumerable <int> GetData()
{
yield return(++count);
yield return(++count);
yield return(++count);
}
var enumerator1 = cachedEnumerable.GetEnumerator();
var enumerator2 = cachedEnumerable.GetEnumerator();
// Act & assert
Assert.True(enumerator1.MoveNext());
Assert.Equal(1, enumerator1.Current);
Assert.Equal(1, count);
Assert.True(enumerator2.MoveNext());
Assert.Equal(1, enumerator2.Current);
Assert.Equal(1, count);
Assert.True(enumerator2.MoveNext());
Assert.Equal(2, enumerator2.Current);
Assert.Equal(2, count);
Assert.True(enumerator2.MoveNext());
Assert.Equal(3, enumerator2.Current);
Assert.Equal(3, count);
Assert.True(enumerator1.MoveNext());
Assert.Equal(2, enumerator1.Current);
Assert.Equal(3, count);
Assert.False(enumerator2.MoveNext());
Assert.True(enumerator1.MoveNext());
Assert.False(enumerator1.MoveNext());
Assert.Equal(3, count);
Assert.Equal(new[] { 1, 2, 3 }, cachedEnumerable);
}
public async Task MultipleConcurrentEnumerations_ShouldEnumerateOnce_ThreadSafe()
{
// Arrange
var maxCount = 1000;
var threadCount = 16;
var resetEvent = new ManualResetEventSlim(initialState: false);
var count = 0;
var cachedEnumerable = CachedEnumerable.Create(new SingleEnumerable <int>(GetData()));
IEnumerable <int> GetData()
{
for (var i = 0; i < maxCount; i++)
{
yield return(++count);
}
}
var results = new List <int> [1000];
var task = Task.Run(() => Parallel.For(0, 1000, new ParallelOptions {
MaxDegreeOfParallelism = threadCount
}, i =>
{
results[i] = cachedEnumerable.ToList();
}));
resetEvent.Set();
await task;
// Act & assert
Assert.Equal(maxCount, count);
foreach (var result in results)
{
Assert.Equal(Enumerable.Range(1, maxCount), result);
}
}
public void CollectionCreate01()
{
using var result = CachedEnumerable.Create(this.PersonProperList);
this.Consumer.Consume(result);
}
/// <summary>
/// Instantiates and returns a <see cref="CachedEnumerable{T}"/> for a given <paramref name="enumerable"/>.
/// Notice: The first item is always iterated through.
/// </summary>
public static CachedEnumerable <T> ToCachedEnumerable <T>(this IEnumerable <T> enumerable)
{
return(CachedEnumerable <T> .Create(enumerable));
}