Caching

In order to operate, [[net.lewisship.cli-tools/dispatch]] has to load all namespaces, to execute the defcommand macros in each, and collect meta-data from all the namespaces and command functions. Thanks to Babashka, this is extremely fast, but is made faster using caching.

dispatch builds a cache based on the options passed to it, and the contents of the classpath; it can then load the data it needs to operate from the cache, if such data is present.

When executing from the cache, dispatch will ultimately load only a single namespace, to invoke the single command function. This allows a complex tool, one with potentially hundreds of commands, to still execute the body of the defcommand within milliseconds.

This may have an even more significant impact for a tool that is built on top of Clojure, rather than Babashka. Our mockup of 1500 commands across 250 namespaces executes twice as fast using the cache (approximately 8 seconds with the cache, vs. 17 seconds without).

Babashka is amazingly fast for these purposes; the same test executes in 0.23 seconds.

By default, dispatch will store its cache in the ~/.cli-tools-cache directory; the environment variable CLI_TOOLS_CACHE_DIR can override this default.

Alternately, you can also specify a path as the :cache-dir option.