目录文件大小计算 - 如何使它更快吗？ [英] Directory file size calculation - how to make it faster?

问题描述

使用C＃，我发现一个目录的总大小。其中的逻辑是这样的：获取文件夹内的文件。综上所述的总大小。寻找是否有子目录。然后做递归搜索。

Using C#, I am finding the total size of a directory. The logic is this way : Get the files inside the folder. Sum up the total size. Find if there are sub directories. Then do a recursive search.

我尝试另一个方式做到这一点太：使用FSO（ obj.GetFolder（路径）.Size ）。这里没有太大的区别在时间中这两种方法。

I tried one another way to do this too : Using FSO (obj.GetFolder(path).Size). There's not much of difference in time in both these approaches.

现在的问题是，我有文件数以万计的在一个特定的文件夹及其回吐像ATLEAST 2分钟找到该文件夹​​的大小。另外，如果我再次运行程序，它发生得很快（5秒）。我认为Windows是缓存文件大小。

Now the problem is, I have tens of thousands of files in a particular folder and its taking like atleast 2 minute to find the folder size. Also, if I run the program again, it happens very quickly (5 secs). I think the windows is caching the file sizes.

有没有什么办法可以降低当我运行该程序第一次所花费的时间？

Is there any way I can bring down the time taken when I run the program first time??

推荐答案

如果与它摆弄了一会儿，试图并行化，和令人惊讶 - 它加速了这里我的机器上（最多3次在四核），唐知道这是否是在所有情况下有效，但不妨一试...

If fiddled with it a while, trying to Parallelize it, and surprisingly - it speeded up here on my machine (up to 3 times on a quadcore), don't know if it is valid in all cases, but give it a try...

.NET4.0 code（或使用3.5 TaskParallelLibrary）

.NET4.0 Code (or use 3.5 with TaskParallelLibrary)

    private static long DirSize(string sourceDir, bool recurse)
    {
        long size = 0;
        string[] fileEntries = Directory.GetFiles(sourceDir);

        foreach (string fileName in fileEntries)
        {
            Interlocked.Add(ref size, (new FileInfo(fileName)).Length);
        }

        if (recurse)
        {
            string[] subdirEntries = Directory.GetDirectories(sourceDir);

            Parallel.For<long>(0, subdirEntries.Length, () => 0, (i, loop, subtotal) =>
            {
                if ((File.GetAttributes(subdirEntries[i]) & FileAttributes.ReparsePoint) != FileAttributes.ReparsePoint)
                {
                    subtotal += DirSize(subdirEntries[i], true);
                    return subtotal;
                }
                return 0;
            },
                (x) => Interlocked.Add(ref size, x)
            );
        }
        return size;
    }

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