/**
* g_time_zone_unref:
* @tz: a #GTimeZone
*
* Decreases the reference count on @tz.
*
* Since: 2.26
**/
void
g_time_zone_unref (GTimeZone *tz)
{
g_assert (tz->ref_count > 0);
if (g_atomic_int_dec_and_test (&tz->ref_count))
{
G_LOCK(time_zones);
g_hash_table_remove (time_zones, tz->name);
G_UNLOCK(time_zones);
if (tz->zoneinfo)
g_buffer_unref (tz->zoneinfo);
g_free (tz->name);
g_slice_free (GTimeZone, tz);
}
}
/**
* g_variant_unref:
* @value: a #GVariant
*
* Decreases the reference count of @value. When its reference count
* drops to 0, the memory used by the variant is freed.
*
* Since: 2.24
**/
void
g_variant_unref (GVariant *value)
{
if (g_atomic_int_dec_and_test (&value->ref_count))
{
if G_UNLIKELY (value->state & STATE_LOCKED)
g_critical ("attempting to free a locked GVariant instance. "
"This should never happen.");
value->state |= STATE_LOCKED;
g_variant_type_info_unref (value->type_info);
if (value->state & STATE_SERIALISED)
g_buffer_unref (value->contents.serialised.buffer);
else
g_variant_release_children (value);
memset (value, 0, sizeof (GVariant));
g_slice_free (GVariant, value);
}
}
/**
* g_time_zone_new:
* @identifier: (allow-none): a timezone identifier
*
* Creates a #GTimeZone corresponding to @identifier.
*
* @identifier can either be an RFC3339/ISO 8601 time offset or
* something that would pass as a valid value for the
* <varname>TZ</varname> environment variable (including %NULL).
*
* Valid RFC3339 time offsets are <literal>"Z"</literal> (for UTC) or
* <literal>"±hh:mm"</literal>. ISO 8601 additionally specifies
* <literal>"±hhmm"</literal> and <literal>"±hh"</literal>.
*
* The <varname>TZ</varname> environment variable typically corresponds
* to the name of a file in the zoneinfo database, but there are many
* other possibilities. Note that those other possibilities are not
* currently implemented, but are planned.
*
* g_time_zone_new_local() calls this function with the value of the
* <varname>TZ</varname> environment variable. This function itself is
* independent of the value of <varname>TZ</varname>, but if @identifier
* is %NULL then <filename>/etc/localtime</filename> will be consulted
* to discover the correct timezone.
*
* See <ulink
* url='http://tools.ietf.org/html/rfc3339#section-5.6'>RFC3339
* §5.6</ulink> for a precise definition of valid RFC3339 time offsets
* (the <varname>time-offset</varname> expansion) and ISO 8601 for the
* full list of valid time offsets. See <ulink
* url='http://www.gnu.org/s/libc/manual/html_node/TZ-Variable.html'>The
* GNU C Library manual</ulink> for an explanation of the possible
* values of the <varname>TZ</varname> environment variable.
*
* You should release the return value by calling g_time_zone_unref()
* when you are done with it.
*
* Returns: the requested timezone
*
* Since: 2.26
**/
GTimeZone *
g_time_zone_new (const gchar *identifier)
{
GTimeZone *tz;
G_LOCK (time_zones);
if (time_zones == NULL)
time_zones = g_hash_table_new (g_str_hash0,
g_str_equal0);
tz = g_hash_table_lookup (time_zones, identifier);
if (tz == NULL)
{
tz = g_slice_new0 (GTimeZone);
tz->name = g_strdup (identifier);
tz->ref_count = 0;
tz->zoneinfo = zone_for_constant_offset (identifier);
if (tz->zoneinfo == NULL)
{
gchar *filename;
if (identifier != NULL)
{
const gchar *tzdir;
tzdir = getenv ("TZDIR");
if (tzdir == NULL)
tzdir = "/usr/share/zoneinfo";
filename = g_build_filename (tzdir, identifier, NULL);
}
else
filename = g_strdup ("/etc/localtime");
tz->zoneinfo = (GBuffer *) g_mapped_file_new (filename, FALSE, NULL);
g_free (filename);
}
if (tz->zoneinfo != NULL)
{
const struct tzhead *header = tz->zoneinfo->data;
gsize size = tz->zoneinfo->size;
/* we only bother to support version 2 */
if (size < sizeof (struct tzhead) || memcmp (header, "TZif2", 5))
{
g_buffer_unref (tz->zoneinfo);
tz->zoneinfo = NULL;
}
else
{
gint typecnt;
/* we trust the file completely. */
tz->header = (const struct tzhead *)
(((const gchar *) (header + 1)) +
guint32_from_be(header->tzh_ttisgmtcnt) +
guint32_from_be(header->tzh_ttisstdcnt) +
8 * guint32_from_be(header->tzh_leapcnt) +
5 * guint32_from_be(header->tzh_timecnt) +
6 * guint32_from_be(header->tzh_typecnt) +
guint32_from_be(header->tzh_charcnt));
typecnt = guint32_from_be (tz->header->tzh_typecnt);
tz->timecnt = guint32_from_be (tz->header->tzh_timecnt);
tz->trans = (gconstpointer) (tz->header + 1);
tz->indices = (gconstpointer) (tz->trans + tz->timecnt);
tz->infos = (gconstpointer) (tz->indices + tz->timecnt);
tz->abbrs = (gconstpointer) (tz->infos + typecnt);
}
}
g_hash_table_insert (time_zones, tz->name, tz);
}
g_atomic_int_inc (&tz->ref_count);
G_UNLOCK (time_zones);
return tz;
}
