Re: [E-devel] E SVN: kuri trunk/PROTO/esskyuehl/src/modules/mysql

[Gustavo S. B. <bar...@pr...>]

On Wed, Jan 23, 2013 at 12:41 PM, Guillaume Friloux
<gui...@as...> wrote:
> On 23/01/2013 15:34, Gustavo Sverzut Barbieri wrote:
>>
>> On Wed, Jan 23, 2013 at 12:31 PM, Guillaume Friloux
>> <gui...@as...> wrote:
>>>
>>> On 23/01/2013 15:03, Gustavo Sverzut Barbieri wrote:
>>>>
>>>> On Wed, Jan 23, 2013 at 11:00 AM, Enlightenment SVN
>>>> <no-...@en...> wrote:
>>>>>
>>>>> Log:
>>>>> Fix mysql backend to make blobs working.
>>>>>
>>>>>                    blob.ops = NULL;
>>>>>                    blob.memory = row[i].string;
>>>>> -                blob.size = rows->lengths[i];;
>>>>> +                blob.size = rows->lengths[i];
>>>>>                    eina_value_setup(&val, EINA_VALUE_TYPE_BLOB);
>>>>> -                eina_value_set(&val, &blob);
>>>>> +                eina_value_set(&val, blob);
>>>>>                    break;
>>>>
>>>> likely here we need to duplicate row[i].string and use blob.ops =
>>>> EINA_VALUE_BLOB_OPERATIONS_MALLOC?
>>>>
>>> Using operations will fail because the free() pointer will be called 3
>>> times, on the same data : one in the flush of the result_cb from the app,
>>> and two from esql (the first one when getting the row, the second one
>>> when
>>> freeing the structure)
>>
>> that's another bug, need to fix that. it's invalid to flush an
>> eina_value that is already flushed. Maybe I should add a CRITICAL in
>> there to avoid doing such?
>>
> Theres maybe a big mistake.
> Yet, in esql, all the eina_values for strings and blobs doesnt get their
> data duped by eina_value. it uses directly the same pointers.

it doesn't for strings, as I pasted before it will strdup when you
call eina_value_set().

for blob, it does not copy. That part is correct, you give it copied
or not, along with the ops that specify how to copy, convert and free
it.


> Which makes flush to just work as it doesnt frees the data.

this is the lack of blob.ops.


> If you plan to change this, to make eina_value to free the data, then the 3
> modules must be changed.

There is nothing to change in eina_value, maybe a critical error to
alert about double flush.

--
Gustavo Sverzut Barbieri
http://profusion.mobi embedded systems
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