This function uses PQsendQueryParams() instead of the normal PQsendQuery()
allowing you to pass binary data in a cleaner fashion.
A basic call would look something like:
char *mydata = "Hello";
size_t mydata_len = strlen(mydata);
kore_pgsql_query_params(&pgsql, req,
"INSERT INTO foo VALUES($1::text)", KORE_PGSQL_FORMAT_TEXT, 1
mydata, mydata_len, KORE_PGSQL_FORMAT_TEXT);
kore_pgsql_query_params() is variadic, allowing you to pass any
count of parameters where each parameter has the following:
data pointer, data length, type of parameter.
I rather keep the old idioms instead of adding more complex things
on top of the async ones. Especially since the simple layer would
interfear with existing http state machines from your handler.
This simple query allows you to ditch rolling your own
state machine for handling async pgsql states and instead
asks you to provide 3 functions:
- init
- results
- done
You can see the different in complexity in the pgsql example,
which now contains a pgsql_simple.c holding the same asynchronous
query as in pgsql.c but using the simple pgsql api.
You can of course still roll your own in case you want more control.
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.
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.
These 2 functions can be used to move an HTTP request
from/to the active http_requests list. Effectively
putting them to "sleep" or "waking them up".
Sprinkle this through the pgsql and task code.
If used correctly greatly reduces overhead for
managing sleeping tasks.
Joris Vink