These internal functions (loread/lowrite) have quite different signatures from their C equivalents (as opposed to lo_lseek). Found out from the sources that I was using it very incorrectly. But discovered lo_read with a signature different from that documented as the Large Object client interface: ones which don't take a connection parameter at all. This really simplifies my code, which can now be:
size_t inBufSize = 8192;int bytes_read = lo_read(fd, inBuffer, inBufSize);
char* inBuffer = (char*)palloc(inBufSize);
int bytes_read = DatumGetInt32(DirectFunctionCall3(loread, Int32GetDatum(fd), CStringGetDatum(inBuffer), UInt32GetDatum(inBufSize)));
and all is well... just too bad there aren't similarly simple versions of the other lo_{lseek,open,...}.
Thanks for the audience, and keep up the good work!
d.
On 7. jan 2004, at 06:22, David Helgason wrote:
Thank you very much,
I figured I needed to open my own using SPI_connect(). I had assumed that there was sth like a the-connection-this-functions-is-begin-run-through.
Now I'm having problems with
which returns an extremely large number in bytes_read (consistently 46235672), regardless of the contents of inBufSize.
I tried using lo_lseek(fd, 0, SEEK_END) on this fd already, which correctly returned the size of the Large Object, so it's not a question of an invalid descriptor. Also that seek didn't effect the result at all. I guess it's wrong usage of the DatumGet*() / *GetDatum() functions, but I can't see where.
Any suggestions?
d.
On 7. jan 2004, at 05:40, Tom Lane wrote:
David Helgason <[EMAIL PROTECTED]> writes:I'm having trouble finding out how to find the current PGconn connection inside a C function.
What makes you think that "*the* current PGconn" is a valid concept? libpq has always supported multiple active connections.
regards, tom lane
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