Parallel write file c#

Two common ways are to use the StreamWriter and File classes. The StreamWriter constructor takes a full file name and creates the file if it does not exist. The following code example uses a StreamWriter to create and write to a file. The WriteLine method of the StreamWriter writes the next line in the file. WriteLine "Monica Rathbun" ; writer. WriteLine "Vidya Agarwal" ; writer. WriteLine "Mahesh Chand" ; writer. WriteLine "Vijay Anand" ; writer. ReadAllText fullPath ; Console. WriteAllLines method writes a string array to a file.

If the file is not created, it creates a new file. If the file is already created, it will overwrite the existing file. Once file writing is done, it closes the file. Awaits a call to File. WriteAllLinesAsync which:. WriteAllTextAsync which:. There are additional conditions that may cause exceptions when working with the file system, it is best to program defensively.

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Add a comment. Active Oldest Votes. Also if you use Parallel. Foreach, you can avoid the null checking for allFileLines[i]. For this you need to use this overload: Parallel. ProcessorCount ; Parallel. The partitioner here is simple and based on the range and the numbers of cores. Improve this answer. Dudi Keleti Dudi Keleti 1 1 silver badge 4 4 bronze badges.

Do you have an example of how to use the ForEach overload you mentioned? And the custom partitioner? The benefits of this approach: I am not a Parallel. For guru but I suspect that it creates a set of new threads each time it is run, which is time consuming. You can instantiate multiple consumers if the producer is reading in the content faster than the consumer s can process it.

Your code is better segregated so the reading of the file is separated from the processing of the file Single-Responsibility Principle. Gene S Gene S 6 6 silver badges 10 10 bronze badges. I need to read an process millions of files. If you also think that section 3 make more sense to you, I'm also consider to use Gene S offer.

Do you have millions of files, or millions or just lines in one file? Your code suggests the latter, whilst your previous comment the former. For uses the default task scheduler, i. NET thread pool. Tasks in. NET are optimized to use the number of threads equal to the number of cores. Creating more threads than this will actually hurt performance. This is the correct part: a you won't need to block the reading thread, b you won't have to allocate that huge string array.

Show 1 more comment. ReadLines method to get chunks of your file: foreach var batchOfLines in File. ReadLines filePath. RobH RobH I was more interested in how to improve the code I posted though as I am doing something new for me. Do not catch the exceptions? Why not? Catching and handling exceptions is fine - sorry if that wasn't clear.

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