c# - 如何根据 DateTime 值的接近度将两个列表中的所有对象匹配成两个对

Question

我有两个继承自抽象 AbstractLineModel 类的 Requests 和 Responses 列表。响应和请求都包含名为 DateTime 的 DateTime(或不包含)、MethodName 和 GUID。

一个 CallPair 包含一对匹配的 Request 和一个 Response:

public class CallPair
{
    public AbstractLineModel _request { get; set; }
    public AbstractLineModel _response { get; set; }

    public CallPair(AbstractLineModel request, AbstractLineModel response)
    {
        _request = request;
        _response = response;
    }
}

CallPairOrganizer 类将调用组织到以下列表中:

public class CallPairOrganizer
{
    // List of requests and matching responses
    private List<CallPair> _callPairs = new List<CallPair>();
    private List<AbstractLineModel> _lines = new List<AbstractLineModel>();
    private List<AbstractLineModel> _requests = new List<AbstractLineModel>();
    private List<AbstractLineModel> _responses = new List<AbstractLineModel>();
    private List<AbstractLineModel> _unmatchedRequests = new List<AbstractLineModel>();
    private List<AbstractLineModel> _unmatchedResponses = new List<AbstractLineModel>();
}

这是 CallPairOrganizer 类的两个方法:(1) 在较早的 answer 的帮助下，我制作了一个包含 CallPairs 的 List其中与 Response 具有相同 GUID 的 Request 在 Callpair 中匹配:

public void MatchCallPairsByRequestId()
{
    // Finds request that have matching response based on RequestId and create 
    // callpair
    _callPairs = _requests.Distinct().Where(req => !string.IsNullOrEmpty
                     (req.RequestId))
         .Join(_responses.Distinct(),
               req => req.RequestId,
               resp => resp.RequestId,
               (req, resp) => new CallPair(req, resp)).ToList();

    CollectUnmatchedCalls();
}

并且 (2) 我收集所有不匹配的请求和响应如下:

public void CollectUnmatchedCalls()
{
    _unmatchedRequests = 
         _requests.Except(_callPairs.Select(cp => cp._request)).ToList();
    _unmatchedResponses = _responses.Except(_callPairs.Select(cp => 
           cp._response)).ToList();
}

这行得通。下一步是比较不匹配的请求和响应，并根据 DateTime 属性对它们进行排序如果它们具有相同的 MethodName。如果请求和响应彼此最接近，我想将它们匹配到一个 CallPair 中。

对于这部分，我很难弄清楚要使用哪种算法/linq。我希望有人可以向我提供有关如何完成将请求与相同 MethodName 的响应相匹配的任务的见解，如果它们基于 DateTime 彼此接近的话。

Answer 1

那么，您需要找到“最接近”请求的响应吗？

//just some objects for me to play with
var requests =  Enumerable.Range(1).Select(i => new { Time = DateTime.Now, Method = "blah" }).ToList();
var responses =  Enumerable.Range(1).Select(i => new { Time = DateTime.Now, Method = "blah" }).ToList();

foreach (var req in requests)
{
    //In all of the responses - find the one that happened soonest after the request (with the same method name)
    var closestResponse = responses
        .Where(resp => resp.Method == req.Method)
        .OrderBy(resp => resp.Time - req.Time)
        .FirstOrDefault();

    //No more responses - exit
    if(closestResponse == null)
        break;

    responses.Remove(closestResponse);

    //make new call pair, with the closest rseponse
}