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Remove redundant WeakValueDictionary

This commit is contained in:
Steve Sanderson 2018-02-13 19:52:44 +00:00
parent 0eb0555303
commit af98672b17
2 changed files with 0 additions and 62 deletions
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1
src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeDiffBuilder.cs
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@ -2,7 +2,6 @@
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Reflection;
using Microsoft.AspNetCore.Blazor.Components;
using Microsoft.AspNetCore.Blazor.Rendering;

61
src/Microsoft.AspNetCore.Blazor/Rendering/WeakValueDictionary.cs
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@ -1,61 +0,0 @@
// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
using System.Linq;
namespace Microsoft.AspNetCore.Blazor.Rendering
{
internal class WeakValueDictionary<TKey, TValue> where TValue : class
{
private IDictionary<TKey, WeakReference<TValue>> _store
= new Dictionary<TKey, WeakReference<TValue>>();
private int _cullThreshold = 10;
public bool TryGetValue(TKey key, out TValue value)
{
if (_store.TryGetValue(key, out var existingWeakRef))
{
if (existingWeakRef.TryGetTarget(out value))
{
return true;
}
// Since we know it's not there, we might as well drop the entry now
_store.Remove(key);
}
value = default(TValue);
return false;
}
public void Add(TKey key, TValue value)
{
if (_store.TryGetValue(key, out _))
{
throw new ArgumentException($"The given key was already present in the {nameof(WeakValueDictionary<TKey, TValue>)}. Key: {key}");
}
_store[key] = new WeakReference<TValue>(value);
CullIfApplicable();
}
private void CullIfApplicable()
{
if (_store.Count > _cullThreshold)
{
var itemsToRemove = _store.Where(x => !x.Value.TryGetTarget(out _)).ToList();
foreach (var itemToRemove in itemsToRemove)
{
_store.Remove(itemToRemove.Key);
}
if (_store.Count > (_cullThreshold / 2))
{
_cullThreshold *= 2;
}
}
}
}
}