I wanted to make an HTTP POST request with a big file so I composed C# code on .net core like following:
using (var fileStream = new FileStream(filePath, FileMode.Open))
using (var streamContent = new StreamContent(fileStream))
{
var content = new MultipartFormDataContent();
content.Add(streamContent);
resp = await httpClient.PostAsync(requestUri, content);
}
It worked well for me. But, I found that it might be happy if SHA1 can be calculated during this context then it can be used for a simple caching for the POST result.
I found some answers on SO like the following:
How do I do a SHA1 File Checksum in C#?
But, I have no idea how I can use this to my code.
Here is what I tried so far:
byte[] hash = null;
using (SHA1Managed shaForStream = new SHA1Managed())
using (var fs = new FileStream(filePath, FileMode.Open))
using (var streamContent = new StreamContent(fs))
{
var content = new MultipartFormDataContent();
content.Add(streamContent);
resp = await httpClient.PostAsync(requestUri, content);
hash = shaForStream.ComputeHash(fs);
}
It is not working. For example, the sha1 value is the same for different files.
I think I might need to study Stream more. Could you tell me which materials do I need to study for this problem?
p.s, There are a couple of ways to cache request and response i.e., request params and response, but I want to do it with a SHA1 way for testing. I am just curious how I can do calculate something and request POST with only one stream. I can do it by creating two file streams. :)
