Instead of letting http_requests spin, if we cannot allocate
a connection for the request we will queue them up put them to sleep.
When a connection becomes available, we'll wake up a request that
was waiting for a connection and let it continue.
This completely avoids consuming massive amounts of cpu time
when dealing with thousands of requests waiting for a pgsql
worker to become ready.
This way developers can cast assets to char * without first
having to convert it to a proper C string.
The NUL character is NOT included in the length of the asset.
Gone is the ugly KORE_PGSQL macro that hid an overly complex
state machine for the pgsql api.
Gone is the pgsql array that was attached to http_requests.
Gone are the callback hacks inside the pgsql api.
Instead, I strongly encourage people to use the new state machine
api Kore offers to properly deal with asynchronous queries.
The pgsql example in examples/pgsql has been updated to reflect
these changes.
In order to use this, define states for your page handler:
struct http_state mystates[] = {
{ "PAGE_STATE_INIT", page_init },
{ "PAGE_STATE_RESULT", page_result },
};
In your page handler you can then simply call http_state_run() with
your states and http_request. This will cause Kore to start calling
your state callbacks beginning at index 0.
State callbacks have the same prototype as page handlers:
int func(struct http_request *);
However, unlike page handlers they MUST return one of the following:
- HTTP_STATE_OK: All good, just continue the fsm.
- HTTP_STATE_ERROR: Abort fsm and return KORE_RESULT_OK to Kore
(This will cancel the http request).
- HTTP_STATE_RETRY: Return KORE_RESULT_RETRY to Kore.
(Kore will retry your page handler next event loop).
- HTTP_STATE_COMPLETE: The fsm completed, break out cleanly.
Note that using this is completely optional and you can still
use the traditional way of writing page handlers.
The fsm is designed to get rid of the clutter that exists today
in Kore when dealing with non blocking tasks or pgsql calls.
This way we can get our code called whenever a stream is
completed. This cb handler does stand alone from an http_request
and is passed a netbuf data structure.
* Always make sure we end the stream properly
* Check for SPDY_FLOW_WINDOW_MAX on window frame updates
* Kill SPDY_STREAM_BLOCKING, once flow control kicks in its per session
After revisiting why this exists in Kore I decided it
does not belong in this platform and instead of letting
it sit there staring at me I rather just kill it.
