[Mod-auth-devel] DB Pool mods

[Nick K. <ni...@we...>]

Just to let you know, I've added an additional feature that's rather
more powerful than what we already have.  sql_acquire gets a handle
that remains valid and guaranteed unique through the lifetime of
a request.  It can be called any number of times in different phases
of a request, or (most powerfully) in different modules, by the
simple expedient of storing the request's handle in the request_config.


(not yet ported to pg_pool and mysql_pool)

typedef struct {
  SQL* sql ;
  unsigned int flags ;
  apr_reslist_t* dbpool ;
} sql_request ;

static apr_status_t pool_release(void* x) {
  sql_request* req = (sql_request*)x ;
  if ( req->flags & SQL_TRANSACTION_ENABLED )
	req->sql->rollback() ;
  if ( req->flags & SQL_LOCK_ENABLED )
	req->sql->unlock(NULL) ;
  apr_reslist_release(req->dbpool, req->sql) ;
  return APR_SUCCESS ;
}

SQL* sql_acquire(request_rec* r, unsigned int flags) {
  sql_request* req = (sql_request*)
	ap_get_module_config(r->request_config, &valet_sql_module) ;
  if ( ! req ) {
    svr_cfg* svr = (svr_cfg*)
        ap_get_module_config(r->server->module_config, &valet_sql_module) ;
    req = (sql_request*) apr_palloc(r->pool, sizeof(sql_request) ) ;
    req->flags = flags ;
    req->dbpool = svr->dbpool ;
    if ( apr_reslist_acquire(svr->dbpool, (void**)&req->sql)
	!= APR_SUCCESS ) {
      ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
        "Failed to acquire SQL connection from pool") ;
      return NULL ;
    }
    const char* err = req->sql->verify(r->pool) ;
    if ( err ) {
      ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "SQL: %s", err) ;
      apr_reslist_release(svr->dbpool, req->sql) ;
      return NULL ;
    }
    ap_set_module_config(r->request_config, &valet_sql_module, req) ;
    apr_pool_cleanup_register(r->pool, req,
        pool_release, apr_pool_cleanup_null) ;
  } else {
    req->flags |= flags ;  // ensure all required cleanups happen
  }
  return req->sql ;
}


-- 
Nick Kew