UploadStream 1.0.1

High performance file upload streaming for dotnet

Installation

Nuget: https://www.nuget.org/packages/UploadStream

> install-package UploadStream

Features

Optimise multi-part streaming file upload performance, reduced CPU usage ~25% (us) and Memory impact ~50% (gen0 gc).

By default dotnet model form model binding loads the entire stream into memory using IEnumerable<IFormFile> - this is non-ideal for large files where processing of the stream should occur during streaming rather then buffering entire file(s) to memory/disk.

This package allows upload streams to be asynchronously processed via a delegate (StreamFiles<T>(Action<IFormFile> func), maintaining generic model binding functionality with ModelState validation - default form model binding is disabled via a custom [DisableFormModelBinding] attribute.

Usage

[HttpPost("upload")]
// disable default model binding in order to enable processing of streams without buffering entire stream
// (only if additional Model binding is required, if no arguments passed then Form Model binding isn't triggered).
[DisableFormModelBinding]
public async Task<IActionResult> Upload(MyRouteModel routeModel) {
    // returns a generic typed model, alternatively non-generic overload if no model binding is required
    MyModel model = await this.StreamFiles<MyModel>(async formFile => {
        // implement processing of stream as required via an IFormFile interface
        using (var stream = formfile.OpenReadStream())
            await ...
    });
    // ModelState is still validated from model
    if(!ModelState.IsValid)
        ...
}