open_memstream on non-linux?

[Martin Gysel]

Am 13.03.2013 11:39, schrieb Miika Turkia:
> On Wed, Mar 13, 2013 at 11:08 AM, Martin Gysel <me at bearsh.org> wrote:
>> Am 12.03.2013 20:24, schrieb Miika Turkia:
>>> On Tue, Mar 12, 2013 at 2:48 PM, Lubomir I. Ivanov <neolit123 at gmail.com> wrote:
>>>> On 12 March 2013 14:45, Lubomir I. Ivanov <neolit123 at gmail.com> wrote:
>>>>> On 12 March 2013 10:35, Martin Gysel <me at bearsh.org> wrote:
>>>>>> Am 11.03.2013 18:09, schrieb Lubomir I. Ivanov:
>>>>>>> On 11 March 2013 18:19, Dirk Hohndel <dirk at hohndel.org> wrote:
>>>>>>>> There is some discussion and code on working around that here…
>>>>>>>>
>>>>>>>> http://stackoverflow.com/questions/10305095/can-i-replace-a-call-to-open-memstream-with-a-malloc-and-an-implicit-cast
>>>>>>>>
>>>>>>>> which looks way overkill to me.
>>>>>>>>
>>>>>>>> Miika - any way you could reimplement this differently? :-)
>>>>>>>
>>>>>>> here is my attempt for miika's reference.
>>>>>>>
>>>>>>> it also now, uses ./ for the temp zip file, since obviously /tmp/
>>>>>>> isn't portable to non-UNIX OS. instead i would write the temp file in
>>>>>>> the home directory, which we should retrieve in a OS specific way
>>>>>>> using e.g. subsurface_get_home_path().
>>>>>>
>>>>>> For me it seems to be a bad idea to create a tmp file in the home
>>>>>> directory, just image, if subsurface crashes once a tmp file has been
>>>>>> created, it will never get deleted again. there's a reason places like
>>>>>> /tmp are there.
>>>>>>
>>>>>
>>>>> that's certainly true.
>>>>>
>>>>>> looking through the glib's documentation I found
>>>>>> g_mkstemp() or g_file_open_tmp().
>>>>>> g_file_open_tmp() for example takes a filename template (no directory)
>>>>>> creates and opens a tmp file in the appropriate location. it also gives
>>>>>> you the actual name of the file based on the template. there's no
>>>>>> mention that this doesn't work on windows...
>>>>>>
>>>>>
>>>>> yep, g_file_open_tmp() should do it, given g_file_open_tmp() succeeds.
>>>>>
>>>>
>>>> i meant g_get_tmp_dir(), which searches for the temp directory...
>>>
>>> Here is a version (on top of Lubomir's patch) that uses
>>> g_get_tmp_dir() and g_build_filename() to create the temporary file
>>> name.
>>>
>>> miika
>>>
>>
>> maybe it is a little bit nip-picking...
>>
>> from your patch:
>>
>>         struct zip_source *s[dive_table.nr];
>>         struct zip *zip;
>> +       const gchar *tmpdir = g_get_tmp_dir();
>>
>>         /*
>>          * Creating a temporary .DLD file to be eventually uploaded to
>>          * divelogs.de. I wonder if this could be done in-memory.
>>          */
>>
>> -       template = strdup("./export.DLD-XXXXXX");
>> +       template = g_build_filename(tmpdir, "export.DLD-XXXXXX", NULL);
>>         tempfile = (char *)mktemp(template);
>>
>> just wondering why you call g_get_tmp_dir() followed by
>> g_build_filename() followed by mktemp() and not just simple use
>> g_file_open_tmp()? supposing the glib guys did a good job it seems to be
>> less error prone to me...
> 
> I did consider the g_file_open_tmp, but it opens the temp file as well
> as returns the name for the generated file. Thus I would have to close
> the file and give the string for zip_open. Not ideal for our purpose.
> So I just chose to create the full temporary file name  manually and
> give that to open_zip (not ideal either).

ah overlooked that fact...

thx
martin