并行计算流的不同哈希值

Question

我想并行计算一个文件的几个不同的哈希值，以提高我的应用程序的性能。

我有以下代码：

Dim lThreads As List(Of Thread) = New List(Of Thread)()

For i = 0 To algorithms.Count - 1
    Dim index = i

    Dim t As Thread = New Thread(
        New ThreadStart(Sub()
            Dim reader2 as System.IO.FileStream = reader
            reader2.position = 0
            listDigestvalue(index) = CalculateHash(algorithm, listReader(index))
        End Sub))
    t.Name = "Thread of algorithm: " + shortnameofalgorithm
    t.Start()
    lThreads.Add(t)
Next

For i = 0 To lThreads.Count - 1
    lThreads(i).Join()
Next

问题是对于每次执行，程序都不会生成文件的正确哈希值。

是否有另一种方法来并行化这些操作。

提前致谢。

Answer 1

感谢@jmcilhinney，我终于用这段代码解决了我的问题。

Dim reader = New FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read, hashBufferSize)
Dim bytesFile() As Byte = GetStreamAsByteArray(reader)

Dim lTasks As List(Of Task) = New List(Of Task)()

For i = 0 To algorithms.Count - 1
    Dim index = i
    Dim shortnameofalgorithm = algorithms(i).shortname

    Dim t As Task = Task.Run(Sub()
                                 listDigestvalue(index) = CalculateHash(shortnameofalgorithm, bytesFile)
                             End Sub)
    lTasks.Add(t)
Next

Task.WaitAll(lTasks.ToArray)

For j = 0 To lTasks.Count - 1
    algorithms(j).hashValue = listDigestvalue(j)
Next

可以对线程执行相同的操作，但我 select "Tasks" 因为它提高了我的应用程序的性能。

非常感谢。

并行计算流的不同哈希值

Calculate different hashes of stream in parallel

vb.net

parallel-processing

hash

multithreading

sha256