Skip to content

Latest commit

 

History

History
39 lines (29 loc) · 2.88 KB

features-pre-compression.md

File metadata and controls

39 lines (29 loc) · 2.88 KB
Raw
uid
UnoWasmBootstrap.Features.PreCompression

Pre-Compression support

Pre-compression has two modes:

  • In-place, where Brotli compressed files are placed next to original files
  • Legacy, where a web.config file url rewriter rule is used

The parameters for the pre-compression are as follows:

  • WasmShellGenerateCompressedFiles which can be true or false. This property is ignored when building MonoRuntimeDebuggerEnabled is set to true, and true by default when the Configuration property is set to Release
  • WasmShellCompressedExtension is an item group which specifies which files to compress. By default, the wasm, clr, js, json, css, html, dat, ttf, and txt files are pre-compressed. More files can be added as follows:
  <ItemGroup>
    <WasmShellCompressedExtension Include=".db"/>
  </ItemGroup>
  • WasmShellBrotliCompressionQuality which controls the compression quality used to pre-compress the files. Possible values are in the range from 0 to 11. The default value is 7.

Warning

Two-digit compression quality values (10 and higher) are intended for extra-intensive CPU usage and can significantly slow down build time.

  • WasmShellCompressionLayoutMode which can be set to InPlace or Legacy. If not set and for backward compatility reasons, Legacy is automatically selected if a web.config file is detected in the layout, and contains the _compressed_br string.

Support for in-place compression

This mode is to be preferred for web servers that support accept-encoding header file rewriting. In the case of Azure Static WebApps, if a file next to the original one is suffixed with .br, and the client requested for brotli compressed files, the in-place compressed file will be served.

Note

To achieve the same behavior in a standalone ASP.NET Core application the CompressedStaticFiles third-party library can be used.

Support for IIS / Azure WebApp GZip/Brotli pre-compression

The IIS compression support has too many knobs for the size of generated WebAssembly files, which makes the serving of static files inefficient.

The Bootstrapper tooling will generate two folders _compressed_gz and _compressed_br which contain compressed versions of the main files. A set IIS rewriting rules are used to redirect the queries to the requested pre-compressed files, with a preference for Brotli.

When building an application, place the following file in the wwwroot folder to automatically enable the use of pre-compressed files.

Note that the pre-compressed files are optional, and if the rewriting rules are removed or not used (because the site is served without IIS), the original files are available at their normal locations.