79 lines
2.6 KiB
C#
79 lines
2.6 KiB
C#
// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
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using System.Collections.Generic;
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using Xunit;
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namespace System.Web.Mvc.Test
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{
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public class ReaderWriterCacheTest
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{
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[Fact]
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public void PublicFetchOrCreateItemCreatesItemIfNotAlreadyInCache()
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{
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// Arrange
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ReaderWriterCacheHelper<int, string> helper = new ReaderWriterCacheHelper<int, string>();
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Dictionary<int, string> cache = helper.PublicCache;
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// Act
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string item = helper.PublicFetchOrCreateItem(42, () => "new");
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// Assert
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Assert.Equal("new", cache[42]);
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Assert.Equal("new", item);
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}
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[Fact]
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public void PublicFetchOrCreateItemReturnsExistingItemIfFound()
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{
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// Arrange
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ReaderWriterCacheHelper<int, string> helper = new ReaderWriterCacheHelper<int, string>();
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Dictionary<int, string> cache = helper.PublicCache;
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helper.PublicCache[42] = "original";
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// Act
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string item = helper.PublicFetchOrCreateItem(42, () => "new");
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// Assert
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Assert.Equal("original", cache[42]);
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Assert.Equal("original", item);
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}
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[Fact]
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public void PublicFetchOrCreateItemReturnsFirstItemIfTwoThreadsUpdateCacheSimultaneously()
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{
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// Arrange
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ReaderWriterCacheHelper<int, string> helper = new ReaderWriterCacheHelper<int, string>();
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Dictionary<int, string> cache = helper.PublicCache;
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Func<string> creator = delegate()
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{
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// fake a second thread coming along when we weren't looking
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string firstItem = helper.PublicFetchOrCreateItem(42, () => "original");
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Assert.Equal("original", cache[42]);
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Assert.Equal("original", firstItem);
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return "new";
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};
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// Act
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string secondItem = helper.PublicFetchOrCreateItem(42, creator);
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// Assert
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Assert.Equal("original", cache[42]);
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Assert.Equal("original", secondItem);
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}
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private class ReaderWriterCacheHelper<TKey, TValue> : ReaderWriterCache<TKey, TValue>
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{
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public Dictionary<TKey, TValue> PublicCache
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{
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get { return Cache; }
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}
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public TValue PublicFetchOrCreateItem(TKey key, Func<TValue> creator)
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{
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return FetchOrCreateItem(key, creator);
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}
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}
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}
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}
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