[libdbi-devel] [patch] plugin support

[Rainer G. <rge...@hq...>]

As discussed on the -user mailing list, I have created a small patch to
support calling libdbi from plugins (where several plugins may call into
dbi_initialize() not knowing about each other).

I have used the _r naming conventions for the changed functions. Please
note that I needed to change a bit more code as rootconn was also
affected by the requirement.

I have tried to keep as consistent with the libdbi interface as
possible. However, in dbi_initialize_r(), I have slightly different
calling conventions. I now needed to pass a second output parameter (the
instance pointer). Fully in line with existing calling conventions would
be to make dbi_initialize_r() return the dbi_inst handle. However, that
would have required to introduce a new function to query the loaded
driver count. I think this would be more intrusive and probably
confusing to existing code. So I decided to go for a output param.

Please review the patch, comments are of course welcome.

Rainer