Re: libpq object hooks

Merlin Moncure wrote:
> On Wed, May 14, 2008 at 10:44 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I'm wondering why the hooks need names at all. AFAICS all that
>> libpq needs to know about a hook is a callback function address
>> and a void * passthrough pointer.
>
> For reference...here is what libpqtypes has to do to bind via the
> hooking interface:
> http://libpqtypes.esilo.com/browse_source.html?file=hooks.c
>
> Are you proposing something substantially different (not my handle
> suggestion)? How would it work exactly?
>
> merlin
>
>

It is important to see how "NON-hook-callback" functions in libpqtypes
make use of the hook data.

PQparamCreate must get a pointer to the conn hook data
http://libpqtypes.esilo.com/browse_source.html?file=param.c#line24

PQgetf must get a pointer to the result hook data
http://libpqtypes.esilo.com/browse_source.html?file=exec.c#line65

These are NOT hook callbacks. The hook data is NOT isolated to callback
functions. It is memory that is publically accessible, outside hook
implementations.

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Andrew Chernow
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