Re: improve type conversion of SPI_processed in Python

Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
> Here is a patch to improves how PL/Python deals with very large values
> of SPI_processed.  The previous code converts anything that does not fit
> into a C long into a Python float.  But Python long has unlimited
> precision, so we should be using that instead.  And in Python 3, int and
> long as the same, so there is no need to deal with any variations anymore.

I took a quick look at this.  +1 for returning Python long all the time,
but I wonder why the Python version dependency.  Our existing function
PLyLong_FromInt64() believes that PyLong_FromLongLong is unconditionally
available.  I'd be inclined to code PLyObject_FromUint64() as an exact
analog of PLyLong_FromInt64(), ie

    /* on 32 bit platforms "unsigned long" may be too small */
    if (sizeof(uint64) > sizeof(unsigned long))
        return PyLong_FromUnsignedLongLong(DatumGetUInt64(d));
    else
        return PyLong_FromUnsignedLong(DatumGetUInt64(d));

and let Python worry about how to optimize the conversion.

So far as I can tell from
https://docs.python.org/2/c-api/long.html
these functions are available as far back as we could need.
If the buildfarm tells us otherwise, we could deal with it then.

            regards, tom lane