Reduce NotSupportedException

[mikasoukhov]

NuGet Product Used

NuGet SDK

Product Version

sdk

Worked before?

no

Impact

It bothers me. A fix would be nice

Repro Steps & Context

Here is the code line https://github.com/NuGet/NuGet.Client/blob/3f81700cdddeb9d6bda312b90c99be7475bd116b/src/NuGet.Core/NuGet.Packaging/PackageExtraction/StreamExtensions.cs#L101

Why just not to use Stream.CanSeek? To avoid NotSupportedException what is cause drawdown performance on many parallel tasks.

Verbose Logs

No response

[kartheekp-ms]

Looking at the https://learn.microsoft.com/dotnet/api/system.io.stream.canseek?view=net-8.0#remarks, it looks like you are proposing following changes, correct?

long? size = null;
try
{
    if (inputStream.CanSeek)
      size = inputStream.Length;
}

// removed catch block because we are relying on `Stream.CanSeek` to set the `size` variable instead of swallowing `NotSupportedException`

if (_isMMapEnabled && size > 0 && size <= MAX_MMAP_SIZE)
{
    MmapCopy(inputStream, fileFullPath, size.Value);
}
else
{
    FileStreamCopy(inputStream, fileFullPath);
}

Given that you already know the fix, feel free to submit the PR by following https://github.com/NuGet/NuGet.Client/blob/dev/CONTRIBUTING.md guidance.

[aortiz-msft]

@mikasoukhov - We are open to a PR to address this issue. Something that would help in the issue and PR description would be to understand why you are hitting that code path commonly.