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.
First off, I’m modeling these completely after the existing ConnArg / SsnArg / TxnArg, with the exception that they won’t have a limit on the number of slots (why bother?). TSReturnCode TSGlobalArgIndexReserve(const char * name, const char * description, int * arg_idx) TSReturnCode TSGlobalArgIndexNameLookup(const char * name, int * arg__idx, const char ** description) TSReturnCode TSGlobalArgIndexLookup(int arg_idx, const char ** name, const char ** description) void TSGlobalArgSet(TSHttpTxn txnp, int arg_idx, void * arg) void * TSGlobalArgGet(TSHttpTxn txnp, int arg_idx) I’m thinking a simple std::vector here (with a lock for good measure) for reserving and looking up slots by name. As for lookup performance, I don’t think this is a problem though, I imagine the use case here is to call TSGlobalArgIndexReserve() and TSGlobalArgIndexNameLookup() in the Init() functions of plugins that need access to a global slot, and from thereon use the index only. The vector will simply store a void*, the name and description. And discuss. — Leif
