So why do you like this?
- Breaks lots of existing code.
- Less typesafe.
- Makes use more verbose.
It's good how the API has avoided the use of void pointers. We should not
reverse that design goal.
On Wed, Mar 4, 2020 at 12:03 PM Leif Hedstrom <zw...@apache.org> wrote:
>
>
> > On Feb 27, 2020, at 10:13 AM, Leif Hedstrom <zw...@apache.org> wrote:
> >
> > Hi all,
> >
> > This is an idea from Bryan Call, which he suggested as a solution for
> reloadable plugins changes that are now in 9.0.x. I recently ran into a
> different use case (thanks Miles …), which could really benefit
> (performance wise) with such APIs. I *could* use the TxnArg APIs instead,
> but these new global arg APIs would make it noticeable faster (and less
> locking). So, I’m writing up this proposal based on these ideas, for
> discussion / adjustments.
>
>
> After discussions here, and with help from Alan and Bryan, I’ve made some
> significant changes to these APIs now. Here’s the new design:
>
> 1) All old APIs are marked deprecated!
> 2) 5 new APIs are introduced
> 3) The Global (GLB) type of user args is added.
>
>
> Item #2 now makes the API look like this:
>
> tsapi TSReturnCode TSUserArgIndexReserve(TSUserArgType type, const char
> *name, const char *description, int *arg_idx);
> tsapi TSReturnCode TSUserArgIndexNameLookup(TSUserArgType type, const char
> *name, int *arg_idx, const char **description);
> tsapi TSReturnCode TSUserArgIndexLookup(TSUserArgType type, int arg_idx,
> const char **name, const char **description);
>
> tsapi void TSUserArgSet(void *data, int arg_idx, void *arg);
> tsapi void *TSUserArgGet(void *data, int arg_idx);
>
>
> The first three now takes a TSUserArgType argument:
>
> typedef enum {
> TS_USER_ARGS_TXN, ///< Transaction based.
> TS_USER_ARGS_SSN, ///< Session based
> TS_USER_ARGS_VCONN, ///< VConnection based
> TS_USER_ARGS_GLB, ///< Global based
> TS_USER_ARGS_COUNT ///< Fake enum, # of valid entries.
> } TSUserArgType;
>
>
>
> The Get()/Set() are then context sensitive. You pass in a “txnp”, it uses
> the TXN slots, you pass in a “ssnp”, it uses the SSN slot. For the “GLB”
> slots, simply pass in a nullptr (since the global doesn’t have a context).
>
> Thoughts? One question is if we should change the “int” type on the index
> to e.g. “size_t”. That’s slightly unorthodox for our existing APIs, where
> we frivolously use “int” for such things (so size_t would be somewhat
> unorthodox in ts/ts.h).
>
> — Leif
>
>
>
