Re: custom function for converting human readable sizes to bytes

On Mon, Jan 4, 2016 at 6:03 PM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
wrote:
>
> 2016-01-04 17:48 GMT+01:00 Shulgin, Oleksandr <
oleksandr(dot)shulgin(at)zalando(dot)de>:
>>
>> On Mon, Jan 4, 2016 at 4:51 PM, Robert Haas <robertmhaas(at)gmail(dot)com>
wrote:
>>>
>>> On Mon, Jan 4, 2016 at 10:17 AM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
wrote:
>>> > [ new patch ]
>>>
>>> + case '-':
>>> + ereport(ERROR,
>>> + (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
>>> + errmsg("size cannot be negative")));
>>>
>>> Why not? I bet if you copy any - sign to the buffer, this will Just
Work.
>>
>>
>> I'm also inclined on dropping that explicit check for empty string below
and let numeric_in() error out on that. Does this look OK, or can it
confuse someone:
>>
>> postgres=# select pg_size_bytes('');
>> ERROR: invalid input syntax for type numeric: ""
>>
>> ?
>>
>>> + if ( conv->base_unit == GUC_UNIT_KB &&
>>
>>
>> Between "(" and "conv->..." I believe.
>
>
> both fixed

Hm...

> + switch (*strptr)
> + {
> + /* ignore plus symbol */
> + case '+':
> + case '-':
> + *bufptr++ = *strptr++;
> + break;
> + }

Well, to that amount you don't need any special checks, I'm just not sure
if reported error message is not misleading if we let numeric_in() handle
all the errors. At least it can cope with the leading spaces, +/- and
empty input quite well.

--
Alex