WL#1264 "Per-thread time zone support infrastructure".

Added basic per-thread time zone functionality (based on public
domain elsie-code). Now user can select current time zone
(from the list of time zones described in system tables).
All NOW-like functions honor this time zone, values of TIMESTAMP
type are interpreted as values in this time zone, so now
our TIMESTAMP type behaves similar to Oracle's TIMESTAMP WITH
LOCAL TIME ZONE (or proper PostgresSQL type).
  
WL#1266 "CONVERT_TZ() - basic time with time zone conversion 
function".
  
Fixed problems described in Bug #2336 (Different number of warnings 
when inserting bad datetime as string or as number). This required
reworking of datetime realted warning hadling (they now generated 
at Field object level not in conversion functions).
  
Optimization: Now Field class descendants use table->in_use member
instead of current_thd macro.

1 files changed, 197 insertions, 95 deletions

diff --git a/sql/item_timefunc.cc b/sql/item_timefunc.cc
index 45d66addc9f..a5ea72374c1 100644
--- a/sql/item_timefunc.cc
+++ b/sql/item_timefunc.cc
@@ -894,6 +894,9 @@ longlong Item_func_year::val_int()
 
 longlong Item_func_unix_timestamp::val_int()
 {
+  TIME ltime;
+  bool not_used;
+  
   DBUG_ASSERT(fixed == 1);
   if (arg_count == 0)
     return (longlong) current_thd->query_start();
@@ -903,12 +906,19 @@ longlong Item_func_unix_timestamp::val_int()
     if (field->type() == FIELD_TYPE_TIMESTAMP)
       return ((Field_timestamp*) field)->get_timestamp();
   }
-  String *str=args[0]->val_str(&value);
-  if ((null_value=args[0]->null_value))
+  
+  if (get_arg0_date(&ltime, 0))
   {
-    return 0; /* purecov: inspected */
+    /*
+      We have to set null_value again because get_arg0_date will also set it
+      to true if we have wrong datetime parameter (and we should return 0 in 
+      this case).
+    */
+    null_value= args[0]->null_value;
+    return 0;
   }
-  return (longlong) str_to_timestamp(str->ptr(),str->length());
+  
+  return (longlong) TIME_to_timestamp(current_thd, &ltime, &not_used);
 }
 
 
@@ -1126,23 +1136,14 @@ bool Item_func_from_days::get_date(TIME *ltime, uint fuzzy_date)
 
 void Item_func_curdate::fix_length_and_dec()
 {
-  struct tm start;
-  
   collation.set(&my_charset_bin);
   decimals=0; 
   max_length=MAX_DATE_WIDTH*MY_CHARSET_BIN_MB_MAXLEN;
 
-  store_now_in_tm(current_thd->query_start(),&start);
+  store_now_in_TIME(&ltime);
   
-  /* For getdate */
-  ltime.year=	start.tm_year+1900;
-  ltime.month=	start.tm_mon+1;
-  ltime.day=	start.tm_mday;
-  ltime.hour=	0;
-  ltime.minute=	0;
-  ltime.second=	0;
-  ltime.second_part=0;
-  ltime.neg=0;
+  /* We don't need to set second_part and neg because they already 0 */
+  ltime.hour= ltime.minute= ltime.second= 0;
   ltime.time_type=TIMESTAMP_DATE;
   value= (longlong) TIME_to_ulonglong_date(&ltime);
 }
@@ -1159,31 +1160,39 @@ String *Item_func_curdate::val_str(String *str)
   return str;
 }
 
-bool Item_func_curdate::get_date(TIME *res,
-				 uint fuzzy_date __attribute__((unused)))
+/*
+    Converts current time in my_time_t to TIME represenatation for local
+    time zone. Defines time zone (local) used for whole CURDATE function.
+*/
+void Item_func_curdate_local::store_now_in_TIME(TIME *now_time)
 {
-  *res=ltime;
-  return 0;
+  THD *thd= current_thd;
+  thd->variables.time_zone->gmt_sec_to_TIME(now_time, 
+                                             (my_time_t)thd->query_start());
+  thd->time_zone_used= 1;
 }
 
 
 /*
-    Converts time in time_t to struct tm represenatation for local timezone.
-    Defines timezone (local) used for whole CURDATE function
+    Converts current time in my_time_t to TIME represenatation for UTC
+    time zone. Defines time zone (UTC) used for whole UTC_DATE function.
 */
-void Item_func_curdate_local::store_now_in_tm(time_t now, struct tm *now_tm)
+void Item_func_curdate_utc::store_now_in_TIME(TIME *now_time)
 {
-  localtime_r(&now,now_tm);
+  my_tz_UTC->gmt_sec_to_TIME(now_time, 
+                             (my_time_t)(current_thd->query_start()));
+  /* 
+    We are not flagging this query as using time zone, since it uses fixed
+    UTC-SYSTEM time-zone.
+  */
 }
 
 
-/*
-    Converts time in time_t to struct tm represenatation for UTC
-    Defines timezone (UTC) used for whole UTC_DATE function
-*/
-void Item_func_curdate_utc::store_now_in_tm(time_t now, struct tm *now_tm)
+bool Item_func_curdate::get_date(TIME *res,
+				 uint fuzzy_date __attribute__((unused)))
 {
-  gmtime_r(&now,now_tm);
+  *res=ltime;
+  return 0;
 }
 
 
@@ -1197,17 +1206,12 @@ String *Item_func_curtime::val_str(String *str)
 
 void Item_func_curtime::fix_length_and_dec()
 {
-  struct tm start;
-  String tmp((char*) buff,sizeof(buff), &my_charset_bin);
   TIME ltime;
+  String tmp((char*) buff,sizeof(buff), &my_charset_bin);
 
-  decimals=0; 
-  store_now_in_tm(current_thd->query_start(),&start);
-  ltime.hour=	start.tm_hour;
-  ltime.minute=	start.tm_min;
-  ltime.second=	start.tm_sec;
-  ltime.second_part= 0;
-  ltime.neg= 0;
+  decimals=0;
+  collation.set(&my_charset_bin);
+  store_now_in_TIME(&ltime);
   value= TIME_to_ulonglong_time(&ltime);
   make_time((DATE_TIME_FORMAT *) 0, &ltime, &tmp);
   max_length= buff_length= tmp.length();
@@ -1215,22 +1219,30 @@ void Item_func_curtime::fix_length_and_dec()
 
 
 /*
-    Converts time in time_t to struct tm represenatation for local timezone.
-    Defines timezone (local) used for whole CURTIME function
+    Converts current time in my_time_t to TIME represenatation for local
+    time zone. Defines time zone (local) used for whole CURTIME function.
 */
-void Item_func_curtime_local::store_now_in_tm(time_t now, struct tm *now_tm)
+void Item_func_curtime_local::store_now_in_TIME(TIME *now_time)
 {
-  localtime_r(&now,now_tm);
+  THD *thd= current_thd;
+  thd->variables.time_zone->gmt_sec_to_TIME(now_time, 
+                                             (my_time_t)thd->query_start());
+  thd->time_zone_used= 1;
 }
 
 
 /*
-    Converts time in time_t to struct tm represenatation for UTC.
-    Defines timezone (UTC) used for whole UTC_TIME function
+    Converts current time in my_time_t to TIME represenatation for UTC
+    time zone. Defines time zone (UTC) used for whole UTC_TIME function.
 */
-void Item_func_curtime_utc::store_now_in_tm(time_t now, struct tm *now_tm)
+void Item_func_curtime_utc::store_now_in_TIME(TIME *now_time)
 {
-  gmtime_r(&now,now_tm);
+  my_tz_UTC->gmt_sec_to_TIME(now_time, 
+                             (my_time_t)(current_thd->query_start()));
+  /* 
+    We are not flagging this query as using time zone, since it uses fixed
+    UTC-SYSTEM time-zone.
+  */
 }
 
 
@@ -1244,18 +1256,12 @@ String *Item_func_now::val_str(String *str)
 
 void Item_func_now::fix_length_and_dec()
 {
-  struct tm start;
   String tmp((char*) buff,sizeof(buff),&my_charset_bin);
 
   decimals=0;
   collation.set(&my_charset_bin);
 
-  store_now_in_tm(current_thd->query_start(),&start);
-  
-  /* For getdate */
-  localtime_to_TIME(&ltime, &start);
-  ltime.time_type= TIMESTAMP_DATETIME;
-  
+  store_now_in_TIME(&ltime);
   value= (longlong) TIME_to_ulonglong_datetime(&ltime);
 
   make_datetime((DATE_TIME_FORMAT *) 0, &ltime, &tmp);
@@ -1263,39 +1269,47 @@ void Item_func_now::fix_length_and_dec()
 }
 
 
-bool Item_func_now::get_date(TIME *res,
-			     uint fuzzy_date __attribute__((unused)))
+/*
+    Converts current time in my_time_t to TIME represenatation for local
+    time zone. Defines time zone (local) used for whole NOW function.
+*/
+void Item_func_now_local::store_now_in_TIME(TIME *now_time)
 {
-  *res=ltime;
-  return 0;
+  THD *thd= current_thd;
+  thd->variables.time_zone->gmt_sec_to_TIME(now_time, 
+                                             (my_time_t)thd->query_start());
+  thd->time_zone_used= 1;
 }
 
 
-int Item_func_now::save_in_field(Field *to, bool no_conversions)
+/*
+    Converts current time in my_time_t to TIME represenatation for UTC
+    time zone. Defines time zone (UTC) used for whole UTC_TIMESTAMP function.
+*/
+void Item_func_now_utc::store_now_in_TIME(TIME *now_time)
 {
-  to->set_notnull();
-  to->store_time(&ltime,TIMESTAMP_DATETIME);
-  return 0;
+  my_tz_UTC->gmt_sec_to_TIME(now_time, 
+                             (my_time_t)(current_thd->query_start()));
+  /* 
+    We are not flagging this query as using time zone, since it uses fixed
+    UTC-SYSTEM time-zone.
+  */
 }
 
 
-/*
-    Converts time in time_t to struct tm represenatation for local timezone.
-    Defines timezone (local) used for whole CURRENT_TIMESTAMP function
-*/
-void Item_func_now_local::store_now_in_tm(time_t now, struct tm *now_tm)
+bool Item_func_now::get_date(TIME *res,
+			     uint fuzzy_date __attribute__((unused)))
 {
-  localtime_r(&now,now_tm);
+  *res=ltime;
+  return 0;
 }
 
 
-/*
-    Converts time in time_t to struct tm represenatation for UTC.
-    Defines timezone (UTC) used for whole UTC_TIMESTAMP function
-*/
-void Item_func_now_utc::store_now_in_tm(time_t now, struct tm *now_tm)
+int Item_func_now::save_in_field(Field *to, bool no_conversions)
 {
-  gmtime_r(&now,now_tm);
+  to->set_notnull();
+  to->store_time(&ltime,TIMESTAMP_DATETIME);
+  return 0;
 }
 
 
@@ -1455,7 +1469,7 @@ String *Item_func_date_format::val_str(String *str)
   {
     String *res;
     if (!(res=args[0]->val_str(str)) ||
-	(str_to_time(res->ptr(),res->length(),&l_time)))
+	(str_to_time_with_warn(res->ptr(), res->length(), &l_time)))
       goto null_date;
 
     l_time.year=l_time.month=l_time.day=0;
@@ -1489,24 +1503,31 @@ null_date:
 }
 
 
+void Item_func_from_unixtime::fix_length_and_dec()
+{ 
+  thd= current_thd;
+  collation.set(&my_charset_bin);
+  decimals=0;
+  max_length=MAX_DATETIME_WIDTH*MY_CHARSET_BIN_MB_MAXLEN;
+  thd->time_zone_used= 1;
+}
+
+
 String *Item_func_from_unixtime::val_str(String *str)
 {
-  struct tm tm_tmp;
-  time_t tmp;
-  TIME ltime;
+  TIME time_tmp;
+  my_time_t tmp;
   
   DBUG_ASSERT(fixed == 1);
   tmp= (time_t) args[0]->val_int();
   if ((null_value=args[0]->null_value))
     goto null_date;
-
-  localtime_r(&tmp,&tm_tmp);
-
-  localtime_to_TIME(&ltime, &tm_tmp);
-
+  
+  thd->variables.time_zone->gmt_sec_to_TIME(&time_tmp, tmp);
+  
   if (str->alloc(20*MY_CHARSET_BIN_MB_MAXLEN))
     goto null_date;
-  make_datetime((DATE_TIME_FORMAT *) 0, &ltime, str);
+  make_datetime((DATE_TIME_FORMAT *) 0, &time_tmp, str);
   return str;
 
 null_date:
@@ -1517,28 +1538,109 @@ null_date:
 
 longlong Item_func_from_unixtime::val_int()
 {
-  TIME ltime;
-  struct tm tm_tmp;
-  time_t tmp;
+  TIME time_tmp;
+  my_time_t tmp;
+  
   DBUG_ASSERT(fixed == 1);
 
   tmp= (time_t) (ulong) args[0]->val_int();
   if ((null_value=args[0]->null_value))
     return 0;
-  localtime_r(&tmp,&tm_tmp);
-  localtime_to_TIME(&ltime, &tm_tmp);
-  return (longlong) TIME_to_ulonglong_datetime(&ltime);
+  
+  current_thd->variables.time_zone->gmt_sec_to_TIME(&time_tmp, tmp);
+  
+  return (longlong) TIME_to_ulonglong_datetime(&time_tmp);
 }
 
 bool Item_func_from_unixtime::get_date(TIME *ltime,
 				       uint fuzzy_date __attribute__((unused)))
 {
-  time_t tmp=(time_t) (ulong) args[0]->val_int();
+  my_time_t tmp=(my_time_t) args[0]->val_int();
   if ((null_value=args[0]->null_value))
     return 1;
-  struct tm tm_tmp;
-  localtime_r(&tmp,&tm_tmp);
-  localtime_to_TIME(ltime, &tm_tmp);
+  
+  current_thd->variables.time_zone->gmt_sec_to_TIME(ltime, tmp);
+
+  return 0;
+}
+
+
+void Item_func_convert_tz::fix_length_and_dec()
+{ 
+  String str;
+  
+  thd= current_thd;
+  collation.set(&my_charset_bin);
+  decimals= 0;
+  max_length= MAX_DATETIME_WIDTH*MY_CHARSET_BIN_MB_MAXLEN;
+
+  if (args[1]->const_item())
+    from_tz= my_tz_find(thd, args[1]->val_str(&str));
+  
+  if (args[2]->const_item())
+    to_tz= my_tz_find(thd, args[2]->val_str(&str));
+}
+
+
+String *Item_func_convert_tz::val_str(String *str)
+{
+  TIME time_tmp;
+
+  if (get_date(&time_tmp, 0))
+    return 0;
+  
+  if (str->alloc(20*MY_CHARSET_BIN_MB_MAXLEN))
+  {
+    null_value= 1;
+    return 0;
+  }
+  
+  make_datetime((DATE_TIME_FORMAT *) 0, &time_tmp, str);
+  return str;
+}
+
+
+longlong Item_func_convert_tz::val_int()
+{
+  TIME time_tmp;
+
+  if (get_date(&time_tmp, 0))
+    return 0;
+  
+  return (longlong)TIME_to_ulonglong_datetime(&time_tmp);
+}
+
+
+bool Item_func_convert_tz::get_date(TIME *ltime,
+				       uint fuzzy_date __attribute__((unused)))
+{
+  my_time_t my_time_tmp;
+  bool not_used;
+  String str;
+  
+  if (!args[1]->const_item())
+    from_tz= my_tz_find(thd, args[1]->val_str(&str));
+  
+  if (!args[2]->const_item())
+    to_tz= my_tz_find(thd, args[2]->val_str(&str));
+  
+  if (from_tz==0 || to_tz==0 || get_arg0_date(ltime, 0))
+  {
+    null_value= 1;
+    return 1;
+  }
+
+  /* Check if we in range where we treat datetime values as non-UTC */
+  if (ltime->year < TIMESTAMP_MAX_YEAR && ltime->year > TIMESTAMP_MIN_YEAR ||
+      ltime->year==TIMESTAMP_MAX_YEAR && ltime->month==1 && ltime->day==1 ||
+      ltime->year==TIMESTAMP_MIN_YEAR && ltime->month==12 && ltime->day==31)
+  {
+    my_time_tmp= from_tz->TIME_to_gmt_sec(ltime, &not_used);
+    if (my_time_tmp >= TIMESTAMP_MIN_VALUE && my_time_tmp <= TIMESTAMP_MAX_VALUE)
+      to_tz->gmt_sec_to_TIME(ltime, my_time_tmp);
+  }
+  
+  null_value= 0;
   return 0;
 }
 
@@ -1795,7 +1897,7 @@ longlong Item_extract::val_int()
   else
   {
     String *res= args[0]->val_str(&value);
-    if (!res || str_to_time(res->ptr(),res->length(),&ltime))
+    if (!res || str_to_time_with_warn(res->ptr(), res->length(), &ltime))
     {
       null_value=1;
       return 0;