并发集合的最快迭代? [英] Fastest iterating of concurrent collections?

问题描述

我有一个难题，我需要遍历以下数据结构:

I have a conundrum, I need to iterate over the following data structure:

public ConcurrentDictionary<int, ConcurrentBag<string>> BaseCollection { get; set; }

private void Form1_Load(object sender, EventArgs e)
{
    // Test Data:
    ConcurrentBag<string> One = new ConcurrentBag<string>() { "0", "1", "3", "5", "7", "9" };
    ConcurrentBag<string> Two = new ConcurrentBag<string>() { "0", "2", "4", "6", "8", "10" };
    ConcurrentBag<string> Three = new ConcurrentBag<string>() { "0", "10", "20", "30", "40" };

    // Init new Index:
    BaseCollection = new ConcurrentDictionary<int, ConcurrentBag<string>>();
    BaseCollection[0] = One;
    BaseCollection[1] = Two;
    BaseCollection[2] = Three;
}



private void Find_Click(object sender, EventArgs e)
{
    // 3 Dictionary Items:
    var Items = BaseCollection.Select((k, v) => new { k, v });

   // I am a little stuck...
   // We should only find "0" and "10"
   // Knowing we need to look for "0" I can use the following to find it's frequency using:
   var Item = Items.SelectMany(i => i.k.Value).Select(a => a).Where(a => a == "0");
}

说五个字典项，最多包含数千个并发字符串

Say Five Dictionary Items with up to thousands of ConcurrentBags of strings

我需要找到Dictionary集合之间的字符串匹配.

I need to find String Matches between Dictionary collections.

我想到了嵌套循环，想到了Linq，但是我对Linq并不熟练:

I thought about nested for loops, I thought about Linq, but I am not very skilled at Linq:

BaseCollection.Select((k, v) => new { k, v }).Where((k, v) => k.k.Value == k.k.Value);

如果有人可以指出正确的方向，那么我可以最好的方式考虑一下.谢谢.

If someone can point me in the right direction, so I can think about this in the best way. Thanks.

推荐答案

如果要在所有 ConcurrentBag s中包含唯一条目列表:

If you want a list of unique entries across all of the ConcurrentBags:

var IDs = BaseCollection.SelectMany(u => u.Value);
var duplicateIDs = IDs.Distinct().ToList();

如果您希望这些出现不止一次:

If you want those that appear more than once:

var IDs = BaseCollection.SelectMany(u => u.Value);
var multipleTimes = IDs
    .GroupBy(z => z)
    .Where(z => z.Count() > 1)
    .Select(z => z.Key)
    .ToList();

SelectMany 进行投影以获取所有 ConcurrentBag 中的所有条目. Distinct 删除重复项. GroupBy 和 Where 允许按匹配数进行过滤. ToList 将结果输出为 List< int> .

SelectMany does a projection to get all entries across all of the ConcurrentBags. Distinct removes duplicates. GroupBy and Where allows filtering by how many matches there are. ToList outputs the results as a List<int>.

.Where(z => z.Count() > 1)

也可以替换为:

.Where(z => z.AtLeast(2))

如果您使用 MoreLinq .您需要分析代码(通过多次调用)以查看其是否提高了性能.

这篇关于并发集合的最快迭代?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！