[HACKERS] Large objects.

[Dmitriy Igrishin]

Hey all,

Here is simple test case of LOB usage, please, note the comments:

#include <libpq-fe.h>
#include <libpq/libpq-fs.h>

int main(int argc, char* argv[])
{
  PGconn* c = PQconnectdb("password=test");

  PGresult* r = PQexec(c, "BEGIN");
  PQclear(r);

  const unsigned int id = lo_create(c, 0);

  int fd1 = lo_open(c, id, INV_READ | INV_WRITE);
  int nBytes = lo_write(c, fd1, "D", 1);
  int fd1Pos = lo_lseek(c, fd1, 2147483647, SEEK_SET);
  fd1Pos = lo_lseek(c, fd1, 1, SEEK_CUR);
  nBytes = lo_write(c, fd1, "Dima", 4); // nBytes == 4 ! Should be 0, IMO.
                                                       // If not, where is
my name
                                                       // will be written?

  r = PQexec(c, "COMMIT");
  PQclear(r);

  r = PQexec(c, "BEGIN");
  PQclear(r);

  fd1 = lo_open(c, id, INV_READ | INV_WRITE);
  fd1Pos =  lo_lseek(c, fd1, 0, SEEK_END); // fd1Pos == -2147483647 !

  char buf[16];
  nBytes = lo_read(c, fd1, buf, 4); // nBytes == 0 ! Correct, IMO.

  r = PQexec(c, "COMMIT");
  PQclear(r);

  return 0;
}

Tell me please, why lo_write() returns me the number of bytes "actually
written"
when current write location is out of 2GB ? IMO, in this case it should
returns
at least zero.
lo_read() returns zero in this case, and it is correct, IMO.

-- 
Regards,
Dmitriy