WL#1580: --start-datetime, --stop-datetime, --start-position (alias for --position) and --stop-position

options for mysqlbinlog, with a test file.
This enables user to say "recover my database to how it was this morning at 10:30"
(mysqlbinlog "--stop-datetime=2003-07-29 10:30:00").
Using time functions into client/ made me move them out of sql/ into sql-common/.
+ (small) fix for BUG#4507 "mysqlbinlog --read-from-remote-server sometimes
cannot accept 2 binlogs" (that is, on command line).


client/client_priv.h:
  new options for mysqlbinlog
client/mysqlbinlog.cc:
  WL#1580: --start-datetime, --stop-datetime, --start-position (alias for --position) and --stop-position.
  (small) fix for BUG#4507 "mysqlbinlog --read-from-remote-server sometimes
   cannot accept 2 binlogs".
include/my_time.h:
  importing time functions so that client/ files can use them.
include/mysql_time.h:
  importing time types so that client/ files can use them.
sql-common/my_time.c:
  importing time functions so that client/ files can use them.
sql/mysql_priv.h:
  moving time functions out of sql/ into sql-common/
sql/time.cc:
  moving time functions out of sql/ into sql-common/
sql/tztime.h:
  moving time functions out of sql/ into sql-common/

1 files changed, 155 insertions, 0 deletions

diff --git a/sql-common/my_time.c b/sql-common/my_time.c
index 46c84ac9ba7..24c19be47ba 100644
--- a/sql-common/my_time.c
+++ b/sql-common/my_time.c
@@ -35,6 +35,16 @@ static uchar internal_format_positions[]=
 
 static char time_separator=':';
 
+static ulong const days_at_timestart=719528;	/* daynr at 1970.01.01 */
+uchar days_in_month[]= {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31, 0};
+
+/*
+  Offset of system time zone from UTC in seconds used to speed up 
+  work of my_system_gmt_sec() function.
+*/
+static long my_time_zone=0;
+
+
 /*
   Convert a timestamp string to a MYSQL_TIME value.
 
@@ -559,3 +569,148 @@ fractional:
 }
 
 
+/*
+  Prepare offset of system time zone from UTC for my_system_gmt_sec() func.
+
+  SYNOPSIS
+    init_time()
+*/
+void init_time(void)
+{
+  time_t seconds;
+  struct tm *l_time,tm_tmp;;
+  MYSQL_TIME my_time;
+  bool not_used;
+
+  seconds= (time_t) time((time_t*) 0);
+  localtime_r(&seconds,&tm_tmp);
+  l_time= &tm_tmp;
+  my_time_zone=		3600;		/* Comp. for -3600 in my_gmt_sec */
+  my_time.year=		(uint) l_time->tm_year+1900;
+  my_time.month=	(uint) l_time->tm_mon+1;
+  my_time.day=		(uint) l_time->tm_mday;
+  my_time.hour=		(uint) l_time->tm_hour;
+  my_time.minute=	(uint) l_time->tm_min;
+  my_time.second=	(uint) l_time->tm_sec;
+  my_system_gmt_sec(&my_time, &my_time_zone, &not_used); /* Init my_time_zone */
+}
+
+
+	/* Calculate nr of day since year 0 in new date-system (from 1615) */
+
+long calc_daynr(uint year,uint month,uint day)
+{
+  long delsum;
+  int temp;
+  DBUG_ENTER("calc_daynr");
+
+  if (year == 0 && month == 0 && day == 0)
+    DBUG_RETURN(0);				/* Skip errors */
+  if (year < 200)
+  {
+    if ((year=year+1900) < 1900+YY_PART_YEAR)
+      year+=100;
+  }
+  delsum= (long) (365L * year+ 31*(month-1) +day);
+  if (month <= 2)
+      year--;
+  else
+    delsum-= (long) (month*4+23)/10;
+  temp=(int) ((year/100+1)*3)/4;
+  DBUG_PRINT("exit",("year: %d  month: %d  day: %d -> daynr: %ld",
+		     year+(month <= 2),month,day,delsum+year/4-temp));
+  DBUG_RETURN(delsum+(int) year/4-temp);
+} /* calc_daynr */
+
+
+/*
+  Convert time in MYSQL_TIME representation in system time zone to its
+  my_time_t form (number of seconds in UTC since begginning of Unix Epoch).
+
+  SYNOPSIS
+    my_system_gmt_sec()
+      t               - time value to be converted
+      my_timezone     - pointer to long where offset of system time zone
+                        from UTC will be stored for caching
+      in_dst_time_gap - set to true if time falls into spring time-gap
+
+  NOTES
+    The idea is to cache the time zone offset from UTC (including daylight 
+    saving time) for the next call to make things faster. But currently we 
+    just calculate this offset during startup (by calling init_time() 
+    function) and use it all the time.
+    Time value provided should be legal time value (e.g. '2003-01-01 25:00:00'
+    is not allowed).
+
+  RETURN VALUE
+    Time in UTC seconds since Unix Epoch representation.
+*/
+my_time_t 
+my_system_gmt_sec(const MYSQL_TIME *t, long *my_timezone, bool *in_dst_time_gap)
+{
+  uint loop;
+  time_t tmp;
+  struct tm *l_time,tm_tmp;
+  long diff, current_timezone;
+
+  /*
+    Calculate the gmt time based on current time and timezone
+    The -1 on the end is to ensure that if have a date that exists twice
+    (like 2002-10-27 02:00:0 MET), we will find the initial date.
+
+    By doing -3600 we will have to call localtime_r() several times, but
+    I couldn't come up with a better way to get a repeatable result :(
+
+    We can't use mktime() as it's buggy on many platforms and not thread safe.
+  */
+  tmp=(time_t) (((calc_daynr((uint) t->year,(uint) t->month,(uint) t->day) -
+		  (long) days_at_timestart)*86400L + (long) t->hour*3600L +
+		 (long) (t->minute*60 + t->second)) + (time_t) my_time_zone -
+		3600);
+  current_timezone= my_time_zone;
+
+  localtime_r(&tmp,&tm_tmp);
+  l_time=&tm_tmp;
+  for (loop=0;
+       loop < 2 &&
+	 (t->hour != (uint) l_time->tm_hour ||
+	  t->minute != (uint) l_time->tm_min);
+       loop++)
+  {					/* One check should be enough ? */
+    /* Get difference in days */
+    int days= t->day - l_time->tm_mday;
+    if (days < -1)
+      days= 1;					// Month has wrapped
+    else if (days > 1)
+      days= -1;
+    diff=(3600L*(long) (days*24+((int) t->hour - (int) l_time->tm_hour)) +
+	  (long) (60*((int) t->minute - (int) l_time->tm_min)));
+    current_timezone+= diff+3600;		// Compensate for -3600 above
+    tmp+= (time_t) diff;
+    localtime_r(&tmp,&tm_tmp);
+    l_time=&tm_tmp;
+  }
+  /*
+    Fix that if we are in the not existing daylight saving time hour
+    we move the start of the next real hour
+  */
+  if (loop == 2 && t->hour != (uint) l_time->tm_hour)
+  {
+    int days= t->day - l_time->tm_mday;
+    if (days < -1)
+      days=1;					// Month has wrapped
+    else if (days > 1)
+      days= -1;
+    diff=(3600L*(long) (days*24+((int) t->hour - (int) l_time->tm_hour))+
+	  (long) (60*((int) t->minute - (int) l_time->tm_min)));
+    if (diff == 3600)
+      tmp+=3600 - t->minute*60 - t->second;	// Move to next hour
+    else if (diff == -3600)
+      tmp-=t->minute*60 + t->second;		// Move to previous hour
+
+    *in_dst_time_gap= 1;
+  }
+  *my_timezone= current_timezone;
+  
+  return (my_time_t) tmp;
+} /* my_system_gmt_sec */