Async Zip-on-the-Fly

Example of dynamically generating a zip file download from ASP.NET, with minimal threading and memory usage.

Specifically, with this code:

• No file is ever completely in memory at any time. As files are read, they are immediately compressed and sent to the browser.
• No threads are ever blocked waiting on reads or writes. The fully-asynchronous code permits threads to return to the thread pool unless they are actually executing code.

There are four examples in this repository, each on its own branch:

• core-ziparchive - ASP.NET Core using the built-in ZipArchive
• core-dotnetzip - ASP.NET Core using DotNetZip (which restricts this application to the full .NET Framework)
• full-ziparchive - ASP.NET WebAPI using the built-in ZipArchive
• full-dotnetzip - ASP.NET WebAPI using DotNetZip

Both of the ZipArchive repositories include a workaround for a bug in that class.

Both of the ASP.NET Core repositories include their own FileCallbackResult to asynchronously stream output on demand.