Plack::Middleware::AccessLog::Timed is a subclass of
Plack::Middleware::AccessLog but uses a wrapped body handle to get the
actual response body size %b (even if its not a chunk of array or
a real filehandle) and the time taken to serve the request: %T or
This wraps the response body output stream to capture the time taken
for the PSGI server to read the whole response body.
This would mean, if the middleware is in use, it will prevent some
server-side optimizations like sendfile(2) from working, as well as
middleware like Plack::Middleware::ContentLength cant guess the
body size out of the file handle.
If all you want is to capture the time taken in your PSGI application
and do not want the wrapped body behavior described above, consider instead
applying Plack::Middleware::Runtime and using Plack::Middleware::AccessLog
to log the X-Runtime header.