On 04/02/2010 11:33 AM, Matthias Bolte wrote:
> 2010/4/2 Chris Lalancette <clalance@xxxxxxxxxx>:
>> On 04/02/2010 09:25 AM, Matthias Bolte wrote:
>>> 2010/4/2 Chris Lalancette <clalance@xxxxxxxxxx>:
>>>> Signed-off-by: Chris Lalancette <clalance@xxxxxxxxxx>
>>>> ---
>>>> src/conf/domain_conf.c | 402 ++++++++++++++++++++++++++++++++++++++++++++--
>>>> src/conf/domain_conf.h | 53 ++++++
>>>> src/libvirt_private.syms | 10 ++
>>>> 3 files changed, 455 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
>>>> index e260dce..1971b9a 100644
>>>> --- a/src/conf/domain_conf.c
>>>> +++ b/src/conf/domain_conf.c
>
>>>
>>>> +virDomainSnapshotDefPtr virDomainSnapshotDefParseString(const char *xmlStr,
>>>> + int newSnapshot)
>>>> +{
>>>> + xmlXPathContextPtr ctxt = NULL;
>>>> + xmlDocPtr xml = NULL;
>>>> + xmlNodePtr root;
>>>> + virDomainSnapshotDefPtr def = NULL;
>>>> + virDomainSnapshotDefPtr ret = NULL;
>>>> + char *creation = NULL, *state = NULL;
>>>> + struct timeval tv;
>>>> + struct tm time_info;
>>>> + char timestr[100];
>>>> +
>>>> + xml = virXMLParse(NULL, xmlStr, "domainsnapshot.xml");
>>>> + if (!xml) {
>>>> + virDomainReportError(VIR_ERR_XML_ERROR,
>>>> + "%s",_("failed to parse snapshot xml document"));
>>>> + return NULL;
>>>> + }
>>>> +
>>>> + if ((root = xmlDocGetRootElement(xml)) == NULL) {
>>>> + virDomainReportError(VIR_ERR_INTERNAL_ERROR,
>>>> + "%s", _("missing root element"));
>>>> + goto cleanup;
>>>> + }
>>>> +
>>>> + if (!xmlStrEqual(root->name, BAD_CAST "domainsnapshot")) {
>>>> + virDomainReportError(VIR_ERR_INTERNAL_ERROR,
>>>> + "%s", _("incorrect root element"));
>>>> + goto cleanup;
>>>> + }
>>>> +
>>>> + ctxt = xmlXPathNewContext(xml);
>>>> + if (ctxt == NULL) {
>>>> + virReportOOMError();
>>>> + goto cleanup;
>>>> + }
>>>> +
>>>> + if (VIR_ALLOC(def) < 0) {
>>>> + virReportOOMError();
>>>> + goto cleanup;
>>>> + }
>>>> +
>>>> + ctxt->node = root;
>>>> +
>>>> + def->name = virXPathString("string(./name)", ctxt);
>>>> + if (def->name == NULL) {
>>>> + /* make up a name */
>>>> + gettimeofday(&tv, NULL);
>>>> + localtime_r(&tv.tv_sec, &time_info);
>>>> + strftime(timestr, sizeof(timestr), "%F_%T", &time_info);
>>>> + def->name = strdup(timestr);
>>>> + }
>>>> + if (def->name == NULL) {
>>>> + virReportOOMError();
>>>> + goto cleanup;
>>>> + }
>>>> +
>>>> + def->description = virXPathString("string(./description)", ctxt);
>>>> +
>>>> + if (!newSnapshot) {
>>>> + creation = virXPathString("string(./creationTime)", ctxt);
>>>
>>> I think it should be creationtime or creation_time, but not creationTime.
>>
>> Taking the domain XML as an example, all 3 styles are used (e.g. currentMemory,
>> on_poweroff, and seclabel). I don't really care too much, so I'll do whatever
>> is more comfortable.
>
> I missed currentMemory and since it's already a mixture of all styles
> lets just keep creationTime.
>
>>>> +char *virDomainSnapshotDefFormat(char *domain_uuid,
>>>> + virDomainSnapshotDefPtr def)
>>>> +{
>>>> + virBuffer buf = VIR_BUFFER_INITIALIZER;
>>>> + char timestr[100];
>>>> + struct tm time_info;
>>>> +
>>>> + virBufferAddLit(&buf, "<domainsnapshot>\n");
>>>> + virBufferVSprintf(&buf, " <name>%s</name>\n", def->name);
>>>> + if (def->description)
>>>> + virBufferVSprintf(&buf, " <description>%s</description>\n",
>>>> + def->description);
>>>> + virBufferVSprintf(&buf, " <state>%s</state>\n",
>>>> + virDomainStateTypeToString(def->state));
>>>> + if (def->parent) {
>>>> + virBufferAddLit(&buf, " <parent>\n");
>>>> + virBufferVSprintf(&buf, " <name>%s</name>\n", def->parent);
>>>> + virBufferAddLit(&buf, " </parent>\n");
>>>> + }
>>>> + localtime_r(&def->creationTime, &time_info);
>>>> + strftime(timestr, sizeof(timestr), "%F_%T", &time_info);
>>>
>>> Again, you handle the time in local time. You could use %F_%T%z to
>>> include the local time zone and then handle that in the parsing
>>> function to get a correct UTC time back.
>>>
>>> Maybe a better solution is to just store the Unix time in seconds in
>>> UTC (as returned by the time() function) in the XML and let
>>> applications do the conversion into a more human readable format and
>>> take care of timezone stuff. This way we get rid of the timezone
>>> problem at the libvirt level at all.
>>
>> Well, I was sort of shooting for that by defining the field to be UTC
>> (which I obviously mis-implemented with localtime_r). It would be nice
>> to have a human-readable string in the XML, though, which is why I didn't
>> just use seconds since the Epoch. Can I just use gmtime_r()
>> here to get the time in UTC, and then strptime and mktime above will do the right thing?
>>
>
> I think the problem is that struct tm doesn't contain a timezone
> filed. Therefore, strptime parses a time that is not fixed in a
> timezone. So even If we would use a time format like
>
> 2010-04-02_12:30:58+0200
>
> it won't help with strptime. strptime knows %z for timezone part, but
> just ignores it.
Ah, I see. That does make it a problem.
>
> mktime operates in local time. The man page says:
>
> "The mktime() function converts a broken-down time structure,
> expressed as local time, to calendar time representation"
>
> So gmtime_r doesn't help.
>
> I think we could use seconds since the Epoch from time() as the actual
> value, and attach a human readable version (from strftime with "%a, %d
> %b %Y %H:%M:%S %z" in RFC 2822 format) in a comment like this:
>
> <creationTime>1270221648</creationTime><!-- Fri, 02 Apr 2010
> 17:20:48 +0200 -->
>
> That way we don't need to deal with the subtle timezone stuff as
> seconds since the Epoch is in UTC and we have a human readable version
> in virsh snapshot-dumpxml for example.
>
> Applications then can take the seconds since the Epoch value and
> format it as they like to local time or what ever they prefer.
Yeah, I'll change it over to seconds since the epoch. Thanks.
--
Chris Lalancette
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