Feature request for lcb_create_io_ops

We use the lcb_create_io_ops() function for integrating Couchbase with our own event loop. This function has two modes of operation - if I understand correctly:

1. Use an event loop out of a set of predefined event loops (libev, libevent, etc)

2. Specify a shared .so library file and the name of a function that takes care of the event loop.

For us, the first option does not work. Although we do use libev (which is supported), we use it with static linking as we do not want to rely on libev being available on sometimes outdated target machines. When we tell lcb_create_io_ops() to use libev, the couchbase libev plugin still tries to open the libev.so library file - which is exactly what we do not want.

We have thus opted for the second option, but this is not ideal either. We have implemented the custom event loop in our main application, and not in a .so file. The most simple solution for us would have been to just tell lcb_create_io_ops() the address of our function - instead of the name of a .so file (which we don't have) and the name of this function.

The solution that we now have taken is this: We specify NULL as the name of the .so file, so that couchbase will look in the main application symbol table for the function, and we have added many extra options to the compiler so that the function can actually been found:

  lcb_error_t setup_couchbase_io(int version, lcb_io_opt_t *io, void *arg)
  {
    ...
  }
 
  lcb_io_opt_t ioops;
  struct lcb_create_io_ops_st ciops;
  ciops.version = 1;
  ciops.v.v1.sofile = NULL;
  ciops.v.v1.symbol = "setup_couchbase_io";
  ciops.v.v1.cookie = our_cookie;
 
  lcb_create_io_ops(&ioops, &ciops)
 

And we had to add the following options to the gcc compiler, because the dlsym() method that couchbase uses does not by default find symbols that are loaded from the static libraries (.a files) that we use.

-Wl,-u,setup_couchbase_io -rdynamic

My suggestion would be to make it simpler:

  lcb_error_t setup_couchbase_io(int version, lcb_io_opt_t *io, void *arg)
  {
    ...
  }
 
  lcb_io_opt_t ioops;
  struct lcb_create_io_ops_st ciops;
  ciops.version = 2;
  ciops.v.v2.function = setup_couchbase_io;
  ciops.v.v2.cookie = our_cookie;
 
  lcb_create_io_ops(&ioops, &ciops)

This is faster, simpler, and does not require all those funny compiler options.

Thanks.