[ccache] explanation of ccache stats

[Stéphane Charette]

>
> But I'm looking for explanations of the differences between things
>> like "cache hit direct" and "cache hit preprocessed".  And "no input file".
>
>
> "cache hit (direct)": Cache hit when using the direct mode
> <https://ccache.samba.org/manual.html#_the_direct_mode> (faster).
> "cache hit (preprocessed)": Cache hit when using the preprocessor mode
> <https://ccache.samba.org/manual.html#_the_preprocessor_mode> (slower).
> "no input file": ccache didn't detect any input source code file. For
> example, this happens when you run "ccache gcc --version".
>
>
Thank you.  Two more related questions about the ccache stats:


   - compiler produced no output
   - cache file missing


I created a new web page with some example graphs from the ccache plugins
in case anyone wants to see what it looks like:
https://www.ccoderun.ca/ccache-munin/

Stéphane