Network.Wai.Middleware.Gzip

There are a good amount of requirements that should be fulfilled before a response will actually be gzip encoded by this Middleware, so here's a short summary.

Request requirements:

• The request needs to accept "gzip" in the "Accept-Encoding" header.

• Requests from Internet Explorer 6 will not be encoded. (i.e. if the request's "User-Agent" header contains "MSIE 6")

Response requirements:

• The response isn't already encoded. (i.e. shouldn't already have a "Content-Encoding" header)

• The response isn't a 206 Partial Content (partial content should never be compressed)

• If the response contains a "Content-Length" header, it should be larger than the gzipSizeThreshold.

• The "Content-Type" response header's value should evaluate to True when applied to gzipCheckMime (though GzipPreCompressed will use the ".gz" file regardless of MIME type on any ResponseFile response)

If you would like to use the default settings, using just def is enough. The default settings don't compress file responses, only builder and stream responses, and only if the response passes the MIME and length checks. (cf. defaultCheckMime and gzipSizeThreshold)

To customize your own settings, use the def method and set the fields you would like to change as follows:

myGzipSettings :: GzipSettings
myGzipSettings =
  defaultGzipSettings
    { gzipFiles = GzipCompress
    , gzipCheckMime = myMimeCheckFunction
    , gzipSizeThreshold = 860
    }

def is re-exported for convenience sake, and defaultCheckMime is exported in case anyone wants to use it in defining their own gzipCheckMime function.