[libvirt] [PATCH] python: keep consistent handling of Python integer conversion

[Guannan Ren]

On 10/01/2012 04:08 PM, Michal Privoznik wrote:
> On 28.09.2012 14:29, Guannan Ren wrote:
>> libvirt_ulonglongUnwrap requires the integer type of python obj.
>> But libvirt_longlongUnwrap still could handle python obj of
>> Pyfloat_type which causes the float value to be rounded up
>> to an integer.
>>
>> For example
>>   >>> dom.setSchedulerParameters({'vcpu_quota': 0.88})
>>   0
>> libvirt_longlongUnwrap treats 0.88 as a valid value 0
>>
>> However
>>   >>> dom.setSchedulerParameters({'cpu_shares': 1000.22})
>> libvirt_ulonglongUnwrap will throw out an error
>> "TypeError: an integer is required"
>>
>> The patch make this consistent.
>> ---
>>   python/typewrappers.c | 8 ++++++--
>>   1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/python/typewrappers.c b/python/typewrappers.c
>> index 7580689..d633603 100644
>> --- a/python/typewrappers.c
>> +++ b/python/typewrappers.c
>> @@ -220,7 +220,7 @@ libvirt_ulongUnwrap(PyObject *obj, unsigned long *val)
>>   int
>>   libvirt_longlongUnwrap(PyObject *obj, long long *val)
>>   {
>> -    long long llong_val;
>> +    long long llong_val = -1;
>>   
>>       if (!obj) {
>>           PyErr_SetString(PyExc_TypeError, "unexpected type");
>> @@ -230,7 +230,11 @@ libvirt_longlongUnwrap(PyObject *obj, long long *val)
>>       /* If obj is of PyInt_Type, PyLong_AsLongLong
>>        * will call PyInt_AsLong() to handle it automatically.
>>        */
>> -    llong_val = PyLong_AsLongLong(obj);
>> +    if (PyInt_Check(obj) || PyLong_Check(obj))
>> +        llong_val = PyLong_AsLongLong(obj);
>> +    else
>> +        PyErr_SetString(PyExc_TypeError, "an integer is required");
>> +
>>       if ((llong_val == -1) && PyErr_Occurred())
>>           return -1;
>>   
>>
> I wonder if we are guaranteed that if Py{Int|Long}_Check() returns true,
> PyLong_AsLongLong cannot fail. If this is the case, than this patch can
> be shortened as the check in the bottom context is no longer needed.
> However, if it's not the case, then ACK.
> I tried to read this out of python DOC, but man, my brain is too small
> for that.
>
> Michal

     Thanks for the review.
     I tried to see the source code of PyObject_SetItem where it uses 
PyLong_AsLong() as the follows:
     So I think it should be right for PyLong_AsLongLong too.
     I am going to push this patch after a while.
     ...

		else if (PyLong_Check(key)) {
			long key_value = PyLong_AsLong(key);
			if (key_value == -1 && PyErr_Occurred())
				return -1;
			return PySequence_SetItem(o, key_value, value);
		}
    ...

    Guannan