On Apr 29, 2014, at 8:41 AM, Jan Kaluža <[email protected]> wrote:
>
> Because later we have to match the URL of request with some proxy_worker.
>
> If you configure ProxyPassMatch like this:
> ProxyPassMatch ^/test/(\d+)/foo.jpg http://x/$1/foo.jpg
>
> Then the proxy_worker name would be "http://x/$1/foo.jpg";.
>
> If you receive request with URL "http://x/something/foo.jpg";,
> ap_proxy_get_worker() will have to find out the worker with name
> "http://x/$1/foo.jpg";. The question here is how it would do that?
>
> The answer used in the patch is "we change the worker name to
> http://x/*/foo.jpg"; and check if the URL ("http://x/something/foo.jpg"; in our
> case) matches that worker.
>
> If we store the original name with $N, we will have to find out different way
> how to match the worker (probably emulating wildcard pattern matching)
>
> It would be possible to store only the original name (with "$N" variables),
> store the flag that the proxy worker is using regex and change
> ap_proxy_strcmp_ematch() function to treat "$N" as "*", but I don't see any
> real advantage here.
>
In Yann's suggested patch we don't store match_name where it
belongs; so we'd need to put it in shm, which means more
memory. Instead, we store as is and add a simple char flag
which sez if the stored name is a regex. Much savings.
And I have no idea why storing with $1 -> * somehow makes
things easier or implies a "different way how to match the worker".
Finally, let's think about this deeper...
Assume we do have
ProxyPassMatch ^/test/(\d+)/foo.jpg http://x/$1/foo.jpg
ProxyPassMatch ^/zippy/(\d+)/bar.jpg http://x/$1/omar/propjoe.gif
is the intent/desire to have 2 workers or 1? A worker is, in
some ways, simply a nickname for the socket related to a host and port.
Maybe, in the interests of efficiency and speed, since regexes
are slow as it is, a condition could be specified (a limitation,
as it were), that when using PPM, only everything up to
the 1st potential substitution is considered a unique worker.
![http://x/$1/foo.jpg"](http://x/$1/foo.jpg"){kind=link}
![http://x/something/foo.jpg"](http://x/something/foo.jpg"){kind=link}
![http://x/*/foo.jpg"](http://x/*/foo.jpg"){kind=link}
