io.pedestal.http.body-params/body-params could be more efficient

[hlship]

Description

io.pedestal.http.body-params/body-params determines how to parse the body by matching content types (specified by regular expressions) to functions that parse the request body in a particular encoding (JSON, EDN, etc.) into Clojure data.

Content types are relatively nominal, so using a series of regular expressions to match input content type to parsing function could be improved by caching on actual values.

This does expose an attack vector where an adveserial client sends many requests with randomized content types in an attempt to blow up the cache; therefore, the cache of content types to parsing functions should be size limited.

Pedestal version

0.6.3

[hlship]

Expected gain was a loss (see #811).