[glib] Replace zoneinfo pointers with structs
- From: John Ralls <jralls src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [glib] Replace zoneinfo pointers with structs
- Date: Tue, 18 Dec 2012 23:55:06 +0000 (UTC)
commit 59f2da17490bca084a988092986d6b28d0342bf3
Author: John Ralls <jralls ceridwen us>
Date: Mon Oct 15 14:32:58 2012 -0700
Replace zoneinfo pointers with structs
The approach of sucking a zoneinfo file into a GBytes and working with
pointers into it might be fast, but it's obtuse and not compatible with
Microsoft Windows.
glib/gtimezone.c | 349 ++++++++++++++++++++++++++++++++---------------------
1 files changed, 211 insertions(+), 138 deletions(-)
---
diff --git a/glib/gtimezone.c b/glib/gtimezone.c
index 0f3c6d3..3380f8c 100644
--- a/glib/gtimezone.c
+++ b/glib/gtimezone.c
@@ -115,24 +115,28 @@ struct ttinfo
guint8 tt_abbrind;
};
+typedef struct
+{
+ gint32 gmt_offset;
+ gboolean is_dst;
+ gboolean is_standard;
+ gboolean is_gmt;
+ gchar *abbrev;
+} TransitionInfo;
+
+typedef struct
+{
+ gint64 time;
+ gint info_index;
+} Transition;
+
+
/* GTimeZone structure and lifecycle {{{1 */
struct _GTimeZone
{
gchar *name;
- gchar version;
- GBytes *zoneinfo;
-
- const struct tzhead *header;
- const struct ttinfo *infos;
- union
- {
- const gint32_be *one;
- const gint64_be *two;
- } trans;
- const guint8 *indices;
- const gchar *abbrs;
- gint timecnt;
-
+ GArray *t_info;
+ GArray *transitions;
gint ref_count;
};
@@ -174,9 +178,9 @@ again:
G_UNLOCK(time_zones);
}
- if (tz->zoneinfo)
- g_bytes_unref (tz->zoneinfo);
-
+ g_array_free (tz->t_info, TRUE);
+ if (tz->transitions != NULL)
+ g_array_free (tz->transitions, TRUE);
g_free (tz->name);
g_slice_free (GTimeZone, tz);
@@ -254,6 +258,11 @@ static gboolean
parse_constant_offset (const gchar *name,
gint32 *offset)
{
+ if (g_strcmp0 (name, "UTC") == 0)
+ {
+ *offset = 0;
+ return TRUE;
+ }
switch (*name++)
{
case 'Z':
@@ -275,36 +284,30 @@ parse_constant_offset (const gchar *name,
}
}
-static GBytes *
-zone_for_constant_offset (const gchar *name)
+static void
+zone_for_constant_offset (GTimeZone *gtz, const gchar *name)
{
- const gchar fake_zoneinfo_headers[] =
- "TZif" "2..." "...." "...." "...."
- "\0\0\0\0" "\0\0\0\0" "\0\0\0\0" "\0\0\0\0" "\0\0\0\0" "\0\0\0\0"
- "TZif" "2..." "...." "...." "...."
- "\0\0\0\0" "\0\0\0\0" "\0\0\0\0" "\0\0\0\0" "\0\0\0\1" "\0\0\0\7";
- struct {
- struct tzhead headers[2];
- struct ttinfo info;
- gchar abbr[8];
- } *fake;
gint32 offset;
+ TransitionInfo info;
if (name == NULL || !parse_constant_offset (name, &offset))
- return NULL;
+ return;
- offset = GINT32_TO_BE (offset);
+ info.gmt_offset = offset;
+ info.is_dst = FALSE;
+ info.is_standard = TRUE;
+ info.is_gmt = TRUE;
+ info.abbrev = g_strdup (name);
- fake = g_malloc (sizeof *fake);
- memcpy (fake, fake_zoneinfo_headers, sizeof fake_zoneinfo_headers);
- memcpy (&fake->info.tt_gmtoff, &offset, sizeof offset);
- fake->info.tt_isdst = FALSE;
- fake->info.tt_abbrind = 0;
- strcpy (fake->abbr, name);
- return g_bytes_new_take (fake, sizeof *fake);
+ gtz->t_info = g_array_sized_new (FALSE, TRUE, sizeof (TransitionInfo), 1);
+ g_array_append_val (gtz->t_info, info);
+
+ /* Constant offset, no transitions */
+ gtz->transitions = NULL;
}
+#ifdef G_OS_UNIX
static GBytes*
zone_info_unix (const gchar *identifier)
{
@@ -349,23 +352,25 @@ zone_info_unix (const gchar *identifier)
}
static void
-init_zone_from_iana_info (GTimeZone *tz)
+init_zone_from_iana_info (GTimeZone *gtz, GBytes *zoneinfo)
{
gsize size;
- const struct tzhead *header = g_bytes_get_data (tz->zoneinfo, &size);
-
- if (size < sizeof (struct tzhead) || memcmp (header, "TZif", 4))
- {
- g_bytes_unref (tz->zoneinfo);
- tz->zoneinfo = NULL;
- }
- else
- {
- gint typecnt;
- tz->version = header->tzh_version;
- /* we trust the file completely. */
- if (tz->version == '2')
- tz->header = (const struct tzhead *)
+ guint index;
+ guint32 time_count, type_count, leap_count, isgmt_count;
+ guint32 isstd_count, char_count ;
+ gpointer tz_transitions, tz_type_index, tz_ttinfo;
+ gpointer tz_leaps, tz_isgmt, tz_isstd;
+ gchar* tz_abbrs;
+ guint timesize = sizeof (gint32), countsize = sizeof (gint32);
+ const struct tzhead *header = g_bytes_get_data (zoneinfo, &size);
+
+ g_return_if_fail (size >= sizeof (struct tzhead) &&
+ memcmp (header, "TZif", 4) == 0);
+
+ if (header->tzh_version == '2')
+ {
+ /* Skip ahead to the newer 64-bit data if it's available. */
+ header = (const struct tzhead *)
(((const gchar *) (header + 1)) +
guint32_from_be(header->tzh_ttisgmtcnt) +
guint32_from_be(header->tzh_ttisstdcnt) +
@@ -373,26 +378,59 @@ init_zone_from_iana_info (GTimeZone *tz)
5 * guint32_from_be(header->tzh_timecnt) +
6 * guint32_from_be(header->tzh_typecnt) +
guint32_from_be(header->tzh_charcnt));
- else
- tz->header = header;
+ timesize = sizeof (gint64);
+ }
+ time_count = guint32_from_be(header->tzh_timecnt);
+ type_count = guint32_from_be(header->tzh_typecnt);
+ leap_count = guint32_from_be(header->tzh_leapcnt);
+ isgmt_count = guint32_from_be(header->tzh_ttisgmtcnt);
+ isstd_count = guint32_from_be(header->tzh_ttisstdcnt);
+ char_count = guint32_from_be(header->tzh_charcnt);
+
+ g_assert (type_count == isgmt_count);
+ g_assert (type_count == isstd_count);
+
+ tz_transitions = (gpointer)(header + 1);
+ tz_type_index = tz_transitions + timesize * time_count;
+ tz_ttinfo = tz_type_index + time_count;
+ tz_abbrs = tz_ttinfo + sizeof (struct ttinfo) * type_count;
+ tz_leaps = tz_abbrs + char_count;
+ tz_isstd = tz_leaps + (timesize + countsize) * leap_count;
+ tz_isgmt = tz_isstd + isstd_count;
+
+ gtz->t_info = g_array_sized_new (FALSE, TRUE, sizeof (TransitionInfo),
+ type_count);
+ gtz->transitions = g_array_sized_new (FALSE, TRUE, sizeof (Transition),
+ time_count);
+
+ for (index = 0; index < type_count; index++)
+ {
+ TransitionInfo t_info;
+ struct ttinfo info = ((struct ttinfo*)tz_ttinfo)[index];
+ t_info.gmt_offset = gint32_from_be (info.tt_gmtoff);
+ t_info.is_dst = info.tt_isdst ? TRUE : FALSE;
+ t_info.is_standard = ((guint8*)tz_isstd)[index] ? TRUE : FALSE;
+ t_info.is_gmt = ((guint8*)tz_isgmt)[index] ? TRUE : FALSE;
+ t_info.abbrev = g_strdup (&tz_abbrs[info.tt_abbrind]);
+ g_array_append_val (gtz->t_info, t_info);
+ }
- typecnt = guint32_from_be (tz->header->tzh_typecnt);
- tz->timecnt = guint32_from_be (tz->header->tzh_timecnt);
- if (tz->version == '2')
- {
- tz->trans.two = (gconstpointer) (tz->header + 1);
- tz->indices = (gconstpointer) (tz->trans.two + tz->timecnt);
- }
+ for (index = 0; index < time_count; index++)
+ {
+ Transition trans;
+ if (header->tzh_version == '2')
+ trans.time = gint64_from_be (((gint64_be*)tz_transitions)[index]);
else
- {
- tz->trans.one = (gconstpointer) (tz->header + 1);
- tz->indices = (gconstpointer) (tz->trans.one + tz->timecnt);
- }
- tz->infos = (gconstpointer) (tz->indices + tz->timecnt);
- tz->abbrs = (gconstpointer) (tz->infos + typecnt);
+ trans.time = gint32_from_be (((gint32_be*)tz_transitions)[index]);
+ trans.info_index = ((guint8*)tz_type_index)[index];
+ g_assert (trans.info_index >= 0);
+ g_assert (trans.info_index < gtz->t_info->len);
+ g_array_append_val (gtz->transitions, trans);
}
+ g_bytes_unref (zoneinfo);
}
+#endif
/* Construction {{{1 */
/**
@@ -439,31 +477,46 @@ init_zone_from_iana_info (GTimeZone *tz)
GTimeZone *
g_time_zone_new (const gchar *identifier)
{
- GTimeZone *tz;
- GMappedFile *file;
+ GTimeZone *tz = NULL;
G_LOCK (time_zones);
if (time_zones == NULL)
time_zones = g_hash_table_new (g_str_hash, g_str_equal);
if (identifier)
- tz = g_hash_table_lookup (time_zones, identifier);
- else
- tz = NULL;
-
- if (tz == NULL)
{
- tz = g_slice_new0 (GTimeZone);
- tz->name = g_strdup (identifier);
- tz->ref_count = 0;
+ tz = g_hash_table_lookup (time_zones, identifier);
+ if (tz)
+ {
+ g_atomic_int_inc (&tz->ref_count);
+ G_UNLOCK (time_zones);
+ return tz;
+ }
+ }
+
+ tz = g_slice_new0 (GTimeZone);
+ tz->name = g_strdup (identifier);
+ tz->ref_count = 0;
- tz->zoneinfo = zone_for_constant_offset (identifier);
+ zone_for_constant_offset (tz, identifier);
- if (tz->zoneinfo == NULL)
- tz->zoneinfo = zone_info_unix (identifier);
+ if (tz->t_info == NULL)
+ {
+#ifdef G_OS_UNIX
+ GBytes *zoneinfo = zone_info_unix (identifier);
+ if (!zoneinfo)
+ zone_for_constant_offset (tz, "UTC");
+ else
+ {
+ init_zone_from_iana_info (tz, zoneinfo);
+ g_bytes_unref (zoneinfo);
+ }
+#elif defined G_OS_WIN32
+#endif
+ }
- if (tz->zoneinfo != NULL)
- init_zone_from_iana_info (tz);
+ if (tz->t_info != NULL)
+ {
if (identifier)
g_hash_table_insert (time_zones, tz->name, tz);
}
@@ -518,69 +571,89 @@ g_time_zone_new_local (void)
return g_time_zone_new (getenv ("TZ"));
}
+#define TRANSITION(n) g_array_index (tz->transitions, Transition, n)
+#define TRANSITION_INFO(n) g_array_index (tz->t_info, TransitionInfo, n)
+
/* Internal helpers {{{1 */
-inline static const struct ttinfo *
+/* Note that interval 0 is *before* the first transition time, so
+ * interval 1 gets transitions[0].
+ */
+inline static const TransitionInfo*
interval_info (GTimeZone *tz,
- gint interval)
+ guint interval)
{
- if (interval)
- return tz->infos + tz->indices[interval - 1];
-
- return tz->infos;
+ guint index;
+ g_return_val_if_fail (tz->t_info != NULL, NULL);
+ if (interval && tz->transitions && interval <= tz->transitions->len)
+ index = (TRANSITION(interval - 1)).info_index;
+ else
+ index = 0;
+ return &(TRANSITION_INFO(index));
}
inline static gint64
interval_start (GTimeZone *tz,
- gint interval)
+ guint interval)
{
- if (interval)
- {
- if (tz->version == '2')
- return gint64_from_be (tz->trans.two[interval - 1]);
- else
- return gint32_from_be (tz->trans.one[interval - 1]);
- }
- return G_MININT64;
+ if (!interval || tz->transitions == NULL || tz->transitions->len == 0)
+ return G_MININT64;
+ if (interval > tz->transitions->len)
+ interval = tz->transitions->len;
+ return (TRANSITION(interval - 1)).time;
}
inline static gint64
interval_end (GTimeZone *tz,
- gint interval)
+ guint interval)
{
- if (interval < tz->timecnt)
- {
- if (tz->version == '2')
- return gint64_from_be (tz->trans.two[interval]) - 1;
- else
- return gint32_from_be (tz->trans.one[interval]) - 1;
- }
+ if (tz->transitions && interval < tz->transitions->len)
+ return (TRANSITION(interval)).time - 1;
return G_MAXINT64;
}
inline static gint32
interval_offset (GTimeZone *tz,
- gint interval)
+ guint interval)
{
- return gint32_from_be (interval_info (tz, interval)->tt_gmtoff);
+ g_return_val_if_fail (tz->t_info != NULL, 0);
+ return interval_info (tz, interval)->gmt_offset;
}
inline static gboolean
interval_isdst (GTimeZone *tz,
- gint interval)
+ guint interval)
+{
+ g_return_val_if_fail (tz->t_info != NULL, 0);
+ return interval_info (tz, interval)->is_dst;
+}
+
+
+inline static gboolean
+interval_isgmt (GTimeZone *tz,
+ guint interval)
+{
+ g_return_val_if_fail (tz->t_info != NULL, 0);
+ return interval_info (tz, interval)->is_gmt;
+}
+
+inline static gboolean
+interval_isstandard (GTimeZone *tz,
+ guint interval)
{
- return interval_info (tz, interval)->tt_isdst;
+ return interval_info (tz, interval)->is_standard;
}
-inline static guint8
-interval_abbrind (GTimeZone *tz,
- gint interval)
+inline static gchar*
+interval_abbrev (GTimeZone *tz,
+ guint interval)
{
- return interval_info (tz, interval)->tt_abbrind;
+ g_return_val_if_fail (tz->t_info != NULL, 0);
+ return interval_info (tz, interval)->abbrev;
}
inline static gint64
interval_local_start (GTimeZone *tz,
- gint interval)
+ guint interval)
{
if (interval)
return interval_start (tz, interval) + interval_offset (tz, interval);
@@ -590,9 +663,9 @@ interval_local_start (GTimeZone *tz,
inline static gint64
interval_local_end (GTimeZone *tz,
- gint interval)
+ guint interval)
{
- if (interval < tz->timecnt)
+ if (tz->transitions && interval < tz->transitions->len)
return interval_end (tz, interval) + interval_offset (tz, interval);
return G_MAXINT64;
@@ -600,9 +673,11 @@ interval_local_end (GTimeZone *tz,
static gboolean
interval_valid (GTimeZone *tz,
- gint interval)
+ guint interval)
{
- return interval <= tz->timecnt;
+ if ( tz->transitions == NULL)
+ return interval == 0;
+ return interval <= tz->transitions->len;
}
/* g_time_zone_find_interval() {{{1 */
@@ -640,13 +715,16 @@ g_time_zone_adjust_time (GTimeZone *tz,
gint64 *time_)
{
gint i;
+ guint intervals;
- if (tz->zoneinfo == NULL)
+ if (tz->transitions == NULL)
return 0;
+ intervals = tz->transitions->len;
+
/* find the interval containing *time UTC
* TODO: this could be binary searched (or better) */
- for (i = 0; i < tz->timecnt; i++)
+ for (i = 0; i <= intervals; i++)
if (*time_ <= interval_end (tz, i))
break;
@@ -686,7 +764,7 @@ g_time_zone_adjust_time (GTimeZone *tz,
if (i && *time_ <= interval_local_end (tz, i - 1))
i--;
- else if (i < tz->timecnt &&
+ else if (i < intervals &&
*time_ >= interval_local_start (tz, i + 1))
i++;
}
@@ -730,11 +808,12 @@ g_time_zone_find_interval (GTimeZone *tz,
gint64 time_)
{
gint i;
+ guint intervals;
- if (tz->zoneinfo == NULL)
+ if (tz->transitions == NULL)
return 0;
-
- for (i = 0; i < tz->timecnt; i++)
+ intervals = tz->transitions->len;
+ for (i = 0; i <= intervals; i++)
if (time_ <= interval_end (tz, i))
break;
@@ -758,7 +837,7 @@ g_time_zone_find_interval (GTimeZone *tz,
if (i && time_ <= interval_local_end (tz, i - 1))
i--;
- else if (i < tz->timecnt && time_ >= interval_local_start (tz, i + 1))
+ else if (i < intervals && time_ >= interval_local_start (tz, i + 1))
i++;
}
@@ -787,12 +866,9 @@ const gchar *
g_time_zone_get_abbreviation (GTimeZone *tz,
gint interval)
{
- g_return_val_if_fail (interval_valid (tz, interval), NULL);
-
- if (tz->header == NULL)
- return "UTC";
+ g_return_val_if_fail (interval_valid (tz, (guint)interval), NULL);
- return tz->abbrs + interval_abbrind (tz, interval);
+ return interval_abbrev (tz, (guint)interval);
}
/**
@@ -816,12 +892,9 @@ gint32
g_time_zone_get_offset (GTimeZone *tz,
gint interval)
{
- g_return_val_if_fail (interval_valid (tz, interval), 0);
-
- if (tz->header == NULL)
- return 0;
+ g_return_val_if_fail (interval_valid (tz, (guint)interval), 0);
- return interval_offset (tz, interval);
+ return interval_offset (tz, (guint)interval);
}
/**
@@ -842,10 +915,10 @@ g_time_zone_is_dst (GTimeZone *tz,
{
g_return_val_if_fail (interval_valid (tz, interval), FALSE);
- if (tz->header == NULL)
+ if (tz->transitions == NULL)
return FALSE;
- return interval_isdst (tz, interval);
+ return interval_isdst (tz, (guint)interval);
}
/* Epilogue {{{1 */
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