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followup

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sql/tztime.cc
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......@@ -15,8 +15,8 @@
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/*
Most of the following code and structures were derived from
public domain code from ftp://elsie.nci.nih.gov/pub
Most of the following code and structures were derived from
public domain code from ftp://elsie.nci.nih.gov/pub
(We will refer to this code as to elsie-code further.)
*/
......@@ -50,25 +50,25 @@ typedef struct ttinfo
#ifdef ABBR_ARE_USED
uint tt_abbrind; // Index of start of abbreviation for this time type.
#endif
/*
/*
We don't use tt_ttisstd and tt_ttisgmt members of original elsie-code
struct since we don't support POSIX-style TZ descriptions in variables.
*/
} TRAN_TYPE_INFO;
/* Structure describing leap-second corrections. */
typedef struct lsinfo
{
typedef struct lsinfo
{
my_time_t ls_trans; // Transition time
long ls_corr; // Correction to apply
} LS_INFO;
/*
Structure with information describing ranges of my_time_t shifted to local
Structure with information describing ranges of my_time_t shifted to local
time (my_time_t + offset). Used for local TIME -> my_time_t conversion.
See comments for TIME_to_gmt_sec() for more info.
*/
typedef struct revtinfo
typedef struct revtinfo
{
long rt_offset; // Offset of local time from UTC in seconds
uint rt_type; // Type of period 0 - Normal period. 1 - Spring time-gap
......@@ -82,10 +82,10 @@ typedef struct revtinfo
#endif
/*
Structure which fully describes time zone which is
Structure which fully describes time zone which is
described in our db or in zoneinfo files.
*/
typedef struct st_time_zone_info
typedef struct st_time_zone_info
{
uint leapcnt; // Number of leap-second corrections
uint timecnt; // Number of transitions between time types
......@@ -100,13 +100,13 @@ typedef struct st_time_zone_info
/* Storage for local time types abbreviations. They are stored as ASCIIZ */
char *chars;
#endif
/*
Leap seconds corrections descriptions, this array is shared by
/*
Leap seconds corrections descriptions, this array is shared by
all time zones who use leap seconds.
*/
LS_INFO *lsis;
/*
Starting points and descriptions of shifted my_time_t (my_time_t + offset)
/*
Starting points and descriptions of shifted my_time_t (my_time_t + offset)
ranges on which shifted my_time_t -> my_time_t mapping is linear or undefined.
Used for tm -> my_time_t conversion.
*/
......@@ -117,7 +117,7 @@ typedef struct st_time_zone_info
there are no transitions at all.
*/
TRAN_TYPE_INFO *fallback_tti;
} TIME_ZONE_INFO;
......@@ -128,11 +128,11 @@ static my_bool prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage);
/*
Load time zone description from zoneinfo (TZinfo) file.
SYNOPSIS
tz_load()
name - path to zoneinfo file
sp - TIME_ZONE_INFO structure to fill
sp - TIME_ZONE_INFO structure to fill
RETURN VALUES
0 - Ok
......@@ -145,7 +145,7 @@ tz_load(const char *name, TIME_ZONE_INFO *sp, MEM_ROOT *storage)
int read_from_file;
uint i;
FILE *file;
if (!(file= my_fopen(name, O_RDONLY|O_BINARY, MYF(MY_WME))))
return 1;
{
......@@ -162,7 +162,7 @@ tz_load(const char *name, TIME_ZONE_INFO *sp, MEM_ROOT *storage)
uint ttisstdcnt;
uint ttisgmtcnt;
char *tzinfo_buf;
read_from_file= my_fread(file, u.buf, sizeof(u.buf), MYF(MY_WME));
if (my_fclose(file, MYF(MY_WME)) != 0)
......@@ -170,7 +170,7 @@ tz_load(const char *name, TIME_ZONE_INFO *sp, MEM_ROOT *storage)
if (read_from_file < (int)sizeof(struct tzhead))
return 1;
ttisstdcnt= int4net(u.tzhead.tzh_ttisgmtcnt);
ttisgmtcnt= int4net(u.tzhead.tzh_ttisstdcnt);
sp->leapcnt= int4net(u.tzhead.tzh_leapcnt);
......@@ -185,7 +185,7 @@ tz_load(const char *name, TIME_ZONE_INFO *sp, MEM_ROOT *storage)
(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
return 1;
if ((uint)(read_from_file - (p - u.buf)) <
if ((uint)(read_from_file - (p - u.buf)) <
sp->timecnt * 4 + /* ats */
sp->timecnt + /* types */
sp->typecnt * (4 + 2) + /* ttinfos */
......@@ -206,7 +206,7 @@ tz_load(const char *name, TIME_ZONE_INFO *sp, MEM_ROOT *storage)
#endif
sp->leapcnt * sizeof(LS_INFO))))
return 1;
sp->ats= (my_time_t *)tzinfo_buf;
tzinfo_buf+= ALIGN_SIZE(sp->timecnt * sizeof(my_time_t));
sp->types= (unsigned char *)tzinfo_buf;
......@@ -218,10 +218,10 @@ tz_load(const char *name, TIME_ZONE_INFO *sp, MEM_ROOT *storage)
tzinfo_buf+= ALIGN_SIZE(sp->charcnt);
#endif
sp->lsis= (LS_INFO *)tzinfo_buf;
for (i= 0; i < sp->timecnt; i++, p+= 4)
sp->ats[i]= int4net(p);
for (i= 0; i < sp->timecnt; i++)
{
sp->types[i]= (unsigned char) *p++;
......@@ -231,7 +231,7 @@ tz_load(const char *name, TIME_ZONE_INFO *sp, MEM_ROOT *storage)
for (i= 0; i < sp->typecnt; i++)
{
TRAN_TYPE_INFO * ttisp;
ttisp= &sp->ttis[i];
ttisp->tt_gmtoff= int4net(p);
p+= 4;
......@@ -248,57 +248,57 @@ tz_load(const char *name, TIME_ZONE_INFO *sp, MEM_ROOT *storage)
for (i= 0; i < sp->leapcnt; i++)
{
LS_INFO *lsisp;
lsisp= &sp->lsis[i];
lsisp->ls_trans= int4net(p);
p+= 4;
lsisp->ls_corr= int4net(p);
p+= 4;
}
/*
/*
Since we don't support POSIX style TZ definitions in variables we
don't read further like glibc or elsie code.
don't read further like glibc or elsie code.
*/
}
return prepare_tz_info(sp, storage);
}
#endif /* defined(TZINFO2SQL) || defined(TESTTIME) */
/*
Finish preparation of time zone description for use in TIME_to_gmt_sec()
Finish preparation of time zone description for use in TIME_to_gmt_sec()
and gmt_sec_to_TIME() functions.
SYNOPSIS
prepare_tz_info()
sp - pointer to time zone description
storage - pointer to MEM_ROOT where arrays for map allocated
DESCRIPTION
First task of this function is to find fallback time type which will
be used if there are no transitions or we have moment in time before
any transitions.
Second task is to build "shifted my_time_t" -> my_time_t map used in
First task of this function is to find fallback time type which will
be used if there are no transitions or we have moment in time before
any transitions.
Second task is to build "shifted my_time_t" -> my_time_t map used in
TIME -> my_time_t conversion.
Note: See description of TIME_to_gmt_sec() function first.
In order to perform TIME -> my_time_t conversion we need to build table
which defines "shifted by tz offset and leap seconds my_time_t" ->
my_time_t function wich is almost the same (except ranges of ambiguity)
as reverse function to piecewise linear function used for my_time_t ->
Note: See description of TIME_to_gmt_sec() function first.
In order to perform TIME -> my_time_t conversion we need to build table
which defines "shifted by tz offset and leap seconds my_time_t" ->
my_time_t function wich is almost the same (except ranges of ambiguity)
as reverse function to piecewise linear function used for my_time_t ->
"shifted my_time_t" conversion and which is also specified as table in
zoneinfo file or in our db (It is specified as start of time type ranges
and time type offsets). So basic idea is very simple - let us iterate
and time type offsets). So basic idea is very simple - let us iterate
through my_time_t space from one point of discontinuity of my_time_t ->
"shifted my_time_t" function to another and build our approximation of
reverse function. (Actually we iterate through ranges on which
reverse function. (Actually we iterate through ranges on which
my_time_t -> "shifted my_time_t" is linear function).
RETURN VALUES
0 Ok
1 Error
1 Error
*/
static my_bool
static my_bool
prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
{
my_time_t cur_t= MY_TIME_T_MIN;
......@@ -307,7 +307,7 @@ prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
long cur_offset, cur_corr, cur_off_and_corr;
uint next_trans_idx, next_leap_idx;
uint i;
/*
/*
Temporary arrays where we will store tables. Needed because
we don't know table sizes ahead. (Well we can estimate their
upper bound but this will take extra space.)
......@@ -317,10 +317,10 @@ prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
LINT_INIT(end_l);
/*
Let us setup fallback time type which will be used if we have not any
transitions or if we have moment of time before first transition.
We will find first non-DST local time type and use it (or use first
/*
Let us setup fallback time type which will be used if we have not any
transitions or if we have moment of time before first transition.
We will find first non-DST local time type and use it (or use first
local time type if all of them are DST types).
*/
for (i= 0; i < sp->typecnt && sp->ttis[i].tt_isdst; i++)
......@@ -328,17 +328,17 @@ prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
if (i == sp->typecnt)
i= 0;
sp->fallback_tti= &(sp->ttis[i]);
/*
Let us build shifted my_time_t -> my_time_t map.
/*
Let us build shifted my_time_t -> my_time_t map.
*/
sp->revcnt= 0;
/* Let us find initial offset */
if (sp->timecnt == 0 || cur_t < sp->ats[0])
{
/*
/*
If we have not any transitions or t is before first transition we are using
already found fallback time type which index is already in i.
*/
......@@ -355,7 +355,7 @@ prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
/* let us find leap correction... unprobable, but... */
for (next_leap_idx= 0; next_leap_idx < sp->leapcnt &&
for (next_leap_idx= 0; next_leap_idx < sp->leapcnt &&
cur_t >= sp->lsis[next_leap_idx].ls_trans;
++next_leap_idx)
continue;
......@@ -369,35 +369,35 @@ prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
while (sp->revcnt < TZ_MAX_REV_RANGES - 1)
{
cur_off_and_corr= cur_offset - cur_corr;
/*
/*
We assuming that cur_t could be only overflowed downwards,
we also assume that end_t won't be overflowed in this case.
*/
if (cur_off_and_corr < 0 &&
if (cur_off_and_corr < 0 &&
cur_t < MY_TIME_T_MIN - cur_off_and_corr)
cur_t= MY_TIME_T_MIN - cur_off_and_corr;
cur_l= cur_t + cur_off_and_corr;
/*
/*
Let us choose end_t as point before next time type change or leap
second correction.
*/
end_t= min((next_trans_idx < sp->timecnt) ? sp->ats[next_trans_idx] - 1:
MY_TIME_T_MAX,
(next_leap_idx < sp->leapcnt) ?
(next_leap_idx < sp->leapcnt) ?
sp->lsis[next_leap_idx].ls_trans - 1: MY_TIME_T_MAX);
/*
/*
again assuming that end_t can be overlowed only in positive side
we also assume that end_t won't be overflowed in this case.
*/
if (cur_off_and_corr > 0 &&
end_t > MY_TIME_T_MAX - cur_off_and_corr)
end_t= MY_TIME_T_MAX - cur_off_and_corr;
end_l= end_t + cur_off_and_corr;
if (end_l > cur_max_seen_l)
{
......@@ -423,7 +423,7 @@ prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
break; /* That was too much */
cur_max_seen_l= cur_l - 1;
}
/* Assume here end_l > cur_max_seen_l (because end_l>=cur_l) */
revts[sp->revcnt]= cur_max_seen_l + 1;
......@@ -434,28 +434,28 @@ prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
}
}
if (end_t == MY_TIME_T_MAX ||
(cur_off_and_corr > 0) &&
if (end_t == MY_TIME_T_MAX ||
(cur_off_and_corr > 0) &&
(end_t >= MY_TIME_T_MAX - cur_off_and_corr))
/* end of t space */
break;
cur_t= end_t + 1;
/*
/*
Let us find new offset and correction. Because of our choice of end_t
cur_t can only be point where new time type starts or/and leap
cur_t can only be point where new time type starts or/and leap
correction is performed.
*/
if (sp->timecnt != 0 && cur_t >= sp->ats[0]) /* else reuse old offset */
if (next_trans_idx < sp->timecnt &&
if (next_trans_idx < sp->timecnt &&
cur_t == sp->ats[next_trans_idx])
{
/* We are at offset point */
cur_offset= sp->ttis[sp->types[next_trans_idx]].tt_gmtoff;
++next_trans_idx;
}
if (next_leap_idx < sp->leapcnt &&
cur_t == sp->lsis[next_leap_idx].ls_trans)
{
......@@ -464,7 +464,7 @@ prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
++next_leap_idx;
}
}
/* check if we have had enough space */
if (sp->revcnt == TZ_MAX_REV_RANGES - 1)
return 1;
......@@ -481,7 +481,7 @@ prepare_tz_info(TIME_ZONE_INFO *sp, MEM_ROOT *storage)
memcpy(sp->revts, revts, sizeof(my_time_t) * (sp->revcnt + 1));
memcpy(sp->revtis, revtis, sizeof(REVT_INFO) * sp->revcnt);
return 0;
}
......@@ -506,20 +506,20 @@ static const uint year_lengths[2]=
#define LEAPS_THRU_END_OF(y) ((y) / 4 - (y) / 100 + (y) / 400)
/*
Converts time from my_time_t representation (seconds in UTC since Epoch)
/*
Converts time from my_time_t representation (seconds in UTC since Epoch)
to broken down representation using given local time zone offset.
SYNOPSIS
sec_to_TIME()
tmp - pointer to structure for broken down representation
t - my_time_t value to be converted
offset - local time zone offset
DESCRIPTION
Convert my_time_t with offset to TIME struct. Differs from timesub
(from elsie code) because doesn't contain any leap correction and
TM_GMTOFF and is_dst setting and contains some MySQL specific
Convert my_time_t with offset to TIME struct. Differs from timesub
(from elsie code) because doesn't contain any leap correction and
TM_GMTOFF and is_dst setting and contains some MySQL specific
initialization. Funny but with removing of these we almost have
glibc's offtime function.
*/
......@@ -534,9 +534,9 @@ sec_to_TIME(TIME * tmp, my_time_t t, long offset)
days= t / SECS_PER_DAY;
rem= t % SECS_PER_DAY;
/*
We do this as separate step after dividing t, because this
/*
We do this as separate step after dividing t, because this
allows us handle times near my_time_t bounds without overflows.
*/
rem+= offset;
......@@ -558,12 +558,12 @@ sec_to_TIME(TIME * tmp, my_time_t t, long offset)
representation. This uses "... ??:59:60" et seq.
*/
tmp->second= (uint)(rem % SECS_PER_MIN);
y= EPOCH_YEAR;
while (days < 0 || days >= (long)year_lengths[yleap= isleap(y)])
{
int newy;
newy= y + days / DAYS_PER_NYEAR;
if (days < 0)
newy--;
......@@ -573,7 +573,7 @@ sec_to_TIME(TIME * tmp, my_time_t t, long offset)
y= newy;
}
tmp->year= y;
ip= mon_lengths[yleap];
for (tmp->month= 0; days >= (long) ip[tmp->month]; tmp->month++)
days= days - (long) ip[tmp->month];
......@@ -588,43 +588,43 @@ sec_to_TIME(TIME * tmp, my_time_t t, long offset)
/*
Find time range wich contains given my_time_t value
SYNOPSIS
find_time_range()
t - my_time_t value for which we looking for range
t - my_time_t value for which we looking for range
range_boundaries - sorted array of range starts.
higher_bound - number of ranges
DESCRIPTION
Performs binary search for range which contains given my_time_t value.
Performs binary search for range which contains given my_time_t value.
It has sense if number of ranges is greater than zero and my_time_t value
is greater or equal than beginning of first range. It also assumes that
t belongs to some range specified or end of last is MY_TIME_T_MAX.
With this localtime_r on real data may takes less time than with linear
search (I've seen 30% speed up).
RETURN VALUE
Index of range to which t belongs
*/
static uint
static uint
find_time_range(my_time_t t, const my_time_t *range_boundaries,
uint higher_bound)
{
uint i, lower_bound= 0;
/*
/*
Function will work without this assertion but result would be meaningless.
*/
DBUG_ASSERT(higher_bound > 0 && t >= range_boundaries[0]);
/*
Do binary search for minimal interval which contain t. We preserve:
range_boundaries[lower_bound] <= t < range_boundaries[higher_bound]
invariant and decrease this higher_bound - lower_bound gap twice
range_boundaries[lower_bound] <= t < range_boundaries[higher_bound]
invariant and decrease this higher_bound - lower_bound gap twice
times on each step.
*/
while (higher_bound - lower_bound > 1)
{
i= (lower_bound + higher_bound) >> 1;
......@@ -637,33 +637,33 @@ find_time_range(my_time_t t, const my_time_t *range_boundaries,
}
/*
Find local time transition for given my_time_t.
Find local time transition for given my_time_t.
SYNOPSIS
find_transition_type()
t - my_time_t value to be converted
sp - pointer to struct with time zone description
RETURN VALUE
Pointer to structure in time zone description describing
local time type for given my_time_t.
*/
static
const TRAN_TYPE_INFO *
const TRAN_TYPE_INFO *
find_transition_type(my_time_t t, const TIME_ZONE_INFO *sp)
{
if (unlikely(sp->timecnt == 0 || t < sp->ats[0]))
{
/*
/*
If we have not any transitions or t is before first transition let
us use fallback time type.
*/
return sp->fallback_tti;
}
/*
Do binary search for minimal interval between transitions which
contain t. With this localtime_r on real data may takes less
contain t. With this localtime_r on real data may takes less
time than with linear search (I've seen 30% speed up).
*/
return &(sp->ttis[sp->types[find_time_range(t, sp->ats, sp->timecnt)]]);
......@@ -673,7 +673,7 @@ find_transition_type(my_time_t t, const TIME_ZONE_INFO *sp)
/*
Converts time in my_time_t representation (seconds in UTC since Epoch) to
broken down TIME representation in local time zone.
SYNOPSIS
gmt_sec_to_TIME()
tmp - pointer to structure for broken down represenatation
......@@ -681,14 +681,14 @@ find_transition_type(my_time_t t, const TIME_ZONE_INFO *sp)
sp - pointer to struct with time zone description
TODO
We can improve this function by creating joined array of transitions and
We can improve this function by creating joined array of transitions and
leap corrections. This will require adding extra field to TRAN_TYPE_INFO
for storing number of "extra" seconds to minute occured due to correction
(60th and 61st second, look how we calculate them as "hit" in this
for storing number of "extra" seconds to minute occured due to correction
(60th and 61st second, look how we calculate them as "hit" in this
function).
Under realistic assumptions about frequency of transitions the same array
can be used fot TIME -> my_time_t conversion. For this we need to
implement tweaked binary search which will take into account that some
Under realistic assumptions about frequency of transitions the same array
can be used fot TIME -> my_time_t conversion. For this we need to
implement tweaked binary search which will take into account that some
TIME has two matching my_time_t ranges and some of them have none.
*/
static void
......@@ -700,19 +700,19 @@ gmt_sec_to_TIME(TIME *tmp, my_time_t sec_in_utc, const TIME_ZONE_INFO *sp)
int hit= 0;
int i;
/*
/*
Find proper transition (and its local time type) for our sec_in_utc value.
Funny but again by separating this step in function we receive code
Funny but again by separating this step in function we receive code
which very close to glibc's code. No wonder since they obviously use
the same base and all steps are sensible.
*/
ttisp= find_transition_type(sec_in_utc, sp);
/*
/*
Let us find leap correction for our sec_in_utc value and number of extra
secs to add to this minute.
This loop is rarely used because most users will use time zones without
leap seconds, and even in case when we have such time zone there won't
This loop is rarely used because most users will use time zones without
leap seconds, and even in case when we have such time zone there won't
be many iterations (we have about 22 corrections at this moment (2004)).
*/
for ( i= sp->leapcnt; i-- > 0; )
......@@ -739,7 +739,7 @@ gmt_sec_to_TIME(TIME *tmp, my_time_t sec_in_utc, const TIME_ZONE_INFO *sp)
break;
}
}
sec_to_TIME(tmp, sec_in_utc, ttisp->tt_gmtoff - corr);
tmp->second+= hit;
......@@ -749,25 +749,25 @@ gmt_sec_to_TIME(TIME *tmp, my_time_t sec_in_utc, const TIME_ZONE_INFO *sp)
/*
Converts local time in broken down representation to local
time zone analog of my_time_t represenation.
SYNOPSIS
sec_since_epoch()
year, mon, mday, hour, min, sec - broken down representation.
DESCRIPTION
Converts time in broken down representation to my_time_t representation
ignoring time zone. Note that we cannot convert back some valid _local_
times near ends of my_time_t range because of my_time_t overflow. But we
times near ends of my_time_t range because of my_time_t overflow. But we
ignore this fact now since MySQL will never pass such argument.
RETURN VALUE
Seconds since epoch time representation.
*/
static my_time_t
static my_time_t
sec_since_epoch(int year, int mon, int mday, int hour, int min ,int sec)
{
#ifndef WE_WANT_TO_HANDLE_UNORMALIZED_DATES
/*
/*
It turns out that only whenever month is normalized or unnormalized
plays role.
*/
......@@ -787,7 +787,7 @@ sec_since_epoch(int year, int mon, int mday, int hour, int min ,int sec)
#endif
days+= mday - 1;
return ((days * HOURS_PER_DAY + hour) * MINS_PER_HOUR + min) *
return ((days * HOURS_PER_DAY + hour) * MINS_PER_HOUR + min) *
SECS_PER_MIN + sec;
}
......@@ -795,73 +795,73 @@ sec_since_epoch(int year, int mon, int mday, int hour, int min ,int sec)
/*
Converts local time in broken down TIME representation to my_time_t
representation.
SYNOPSIS
TIME_to_gmt_sec()
t - pointer to structure for broken down represenatation
sp - pointer to struct with time zone description
in_dst_time_gap - pointer to bool which is set to true if datetime
in_dst_time_gap - pointer to bool which is set to true if datetime
value passed doesn't really exist (i.e. falls into
spring time-gap) and is not touched otherwise.
DESCRIPTION
This is mktime analog for MySQL. It is essentially different
This is mktime analog for MySQL. It is essentially different
from mktime (or hypotetical my_mktime) because:
- It has no idea about tm_isdst member so if it
- It has no idea about tm_isdst member so if it
has two answers it will give the smaller one
- If we are in spring time gap then it will return
- If we are in spring time gap then it will return
beginning of the gap
- It can give wrong results near the ends of my_time_t due to
overflows, but we are safe since in MySQL we will never
- It can give wrong results near the ends of my_time_t due to
overflows, but we are safe since in MySQL we will never
call this function for such dates (its restriction for year
between 1970 and 2038 gives us several days of reserve).
- By default it doesn't support un-normalized input. But if
- By default it doesn't support un-normalized input. But if
sec_since_epoch() function supports un-normalized dates
then this function should handle un-normalized input right,
then this function should handle un-normalized input right,
altough it won't normalize structure TIME.
Traditional approach to problem of conversion from broken down
representation to time_t is iterative. Both elsie's and glibc
implementation try to guess what time_t value should correspond to
this broken-down value. They perform localtime_r function on their
guessed value and then calculate the difference and try to improve
Traditional approach to problem of conversion from broken down
representation to time_t is iterative. Both elsie's and glibc
implementation try to guess what time_t value should correspond to
this broken-down value. They perform localtime_r function on their
guessed value and then calculate the difference and try to improve
their guess. Elsie's code guesses time_t value in bit by bit manner,
Glibc's code tries to add difference between broken-down value
Glibc's code tries to add difference between broken-down value
corresponding to guess and target broken-down value to current guess.
It also uses caching of last found correction... So Glibc's approach
is essentially faster but introduces some undetermenism (in case if
It also uses caching of last found correction... So Glibc's approach
is essentially faster but introduces some undetermenism (in case if
is_dst member of broken-down representation (tm struct) is not known
and we have two possible answers).
We use completely different approach. It is better since it is both
We use completely different approach. It is better since it is both
faster than iterative implementations and fully determenistic. If you
look at my_time_t to TIME conversion then you'll find that it consist
of two steps:
The first is calculating shifted my_time_t value and the second - TIME
calculation from shifted my_time_t value (well it is a bit simplified
calculation from shifted my_time_t value (well it is a bit simplified
picture). The part in which we are interested in is my_time_t -> shifted
my_time_t conversion. It is piecewise linear function which is defined
by combination of transition times as break points and times offset
as changing function parameter. The possible inverse function for this
converison would be ambiguos but with MySQL's restrictions we can use
some function which is the same as inverse function on unambigiuos
ranges and coincides with one of branches of inverse function in
other ranges. Thus we just need to build table which will determine
this shifted my_time_t -> my_time_t conversion similar to existing
(my_time_t -> shifted my_time_t table). We do this in
by combination of transition times as break points and times offset
as changing function parameter. The possible inverse function for this
converison would be ambiguos but with MySQL's restrictions we can use
some function which is the same as inverse function on unambigiuos
ranges and coincides with one of branches of inverse function in
other ranges. Thus we just need to build table which will determine
this shifted my_time_t -> my_time_t conversion similar to existing
(my_time_t -> shifted my_time_t table). We do this in
prepare_tz_info function.
TODO
If we can even more improve this function. For doing this we will need to
If we can even more improve this function. For doing this we will need to
build joined map of transitions and leap corrections for gmt_sec_to_TIME()
function (similar to revts/revtis). Under realistic assumptions about
function (similar to revts/revtis). Under realistic assumptions about
frequency of transitions we can use the same array for TIME_to_gmt_sec().
We need to implement special version of binary search for this. Such step
will be beneficial to CPU cache since we will decrease data-set used for
conversion twice.
RETURN VALUE
Seconds in UTC since Epoch.
Seconds in UTC since Epoch.
0 in case of error.
*/
static my_time_t
......@@ -872,20 +872,20 @@ TIME_to_gmt_sec(const TIME *t, const TIME_ZONE_INFO *sp, bool *in_dst_time_gap)
uint i;
DBUG_ENTER("TIME_to_gmt_sec");
/* We need this for correct leap seconds handling */
if (t->second < SECS_PER_MIN)
saved_seconds= 0;
else
saved_seconds= t->second;
/*
/*
NOTE If we want to convert full my_time_t range without MySQL
restrictions we should catch overflow here somehow.
*/
local_t= sec_since_epoch(t->year, t->month, t->day,
t->hour, t->minute,
t->hour, t->minute,
saved_seconds ? 0 : t->second);
/* We have at least one range */
......@@ -893,7 +893,7 @@ TIME_to_gmt_sec(const TIME *t, const TIME_ZONE_INFO *sp, bool *in_dst_time_gap)
if (local_t < sp->revts[0] || local_t > sp->revts[sp->revcnt])
{
/*
/*
This means that source time can't be represented as my_time_t due to
limited my_time_t range.
*/
......@@ -902,10 +902,10 @@ TIME_to_gmt_sec(const TIME *t, const TIME_ZONE_INFO *sp, bool *in_dst_time_gap)
/* binary search for our range */
i= find_time_range(local_t, sp->revts, sp->revcnt);
if (sp->revtis[i].rt_type)
{
/*
/*
Oops! We are in spring time gap.
May be we should return error here?
Now we are returning my_time_t value corresponding to the
......@@ -920,7 +920,7 @@ TIME_to_gmt_sec(const TIME *t, const TIME_ZONE_INFO *sp, bool *in_dst_time_gap)
/*
End of elsie derived code.
End of elsie derived code.
*/
......@@ -933,19 +933,19 @@ static const String tz_SYSTEM_name("SYSTEM", 6, &my_charset_latin1);
/*
Instance of this class represents local time zone used on this system
Instance of this class represents local time zone used on this system
(specified by TZ environment variable or via any other system mechanism).
It uses system functions (localtime_r, my_system_gmt_sec) for conversion
It uses system functions (localtime_r, my_system_gmt_sec) for conversion
and is always available. Because of this it is used by default - if there
were no explicit time zone specified. On the other hand because of this
conversion methods provided by this class is significantly slower and
possibly less multi-threaded-friendly than corresponding Time_zone_db
conversion methods provided by this class is significantly slower and
possibly less multi-threaded-friendly than corresponding Time_zone_db
methods so the latter should be preffered there it is possible.
*/
class Time_zone_system : public Time_zone
class Time_zone_system : public Time_zone
{
public:
virtual my_time_t TIME_to_gmt_sec(const TIME *t,
virtual my_time_t TIME_to_gmt_sec(const TIME *t,
bool *in_dst_time_gap) const;
virtual void gmt_sec_to_TIME(TIME *tmp, my_time_t t) const;
virtual const String * get_name() const;
......@@ -953,31 +953,31 @@ public:
/*
Converts local time in system time zone in TIME representation
Converts local time in system time zone in TIME representation
to its my_time_t representation.
SYNOPSIS
TIME_to_gmt_sec()
t - pointer to TIME structure with local time in
t - pointer to TIME structure with local time in
broken-down representation.
in_dst_time_gap - pointer to bool which is set to true if datetime
in_dst_time_gap - pointer to bool which is set to true if datetime
value passed doesn't really exist (i.e. falls into
spring time-gap) and is not touched otherwise.
DESCRIPTION
This method uses system function (localtime_r()) for conversion
local time in system time zone in TIME structure to its my_time_t
local time in system time zone in TIME structure to its my_time_t
representation. Unlike the same function for Time_zone_db class
it it won't handle unnormalized input properly. Still it will
return lowest possible my_time_t in case of ambiguity or if we
it it won't handle unnormalized input properly. Still it will
return lowest possible my_time_t in case of ambiguity or if we
provide time corresponding to the time-gap.
You should call init_time() function before using this function.
RETURN VALUE
Corresponding my_time_t value or 0 in case of error
*/
my_time_t
my_time_t
Time_zone_system::TIME_to_gmt_sec(const TIME *t, bool *in_dst_time_gap) const
{
long not_used;
......@@ -988,20 +988,20 @@ Time_zone_system::TIME_to_gmt_sec(const TIME *t, bool *in_dst_time_gap) const
/*
Converts time from UTC seconds since Epoch (my_time_t) representation
to system local time zone broken-down representation.
SYNOPSIS
gmt_sec_to_TIME()
tmp - pointer to TIME structure to fill-in
t - my_time_t value to be converted
t - my_time_t value to be converted
NOTE
NOTE
We assume that value passed to this function will fit into time_t range
supported by localtime_r. This conversion is putting restriction on
supported by localtime_r. This conversion is putting restriction on
TIMESTAMP range in MySQL. If we can get rid of SYSTEM time zone at least
for interaction with client then we can extend TIMESTAMP range down to
for interaction with client then we can extend TIMESTAMP range down to
the 1902 easily.
*/
void
void
Time_zone_system::gmt_sec_to_TIME(TIME *tmp, my_time_t t) const
{
struct tm tmp_tm;
......@@ -1015,7 +1015,7 @@ Time_zone_system::gmt_sec_to_TIME(TIME *tmp, my_time_t t) const
/*
Get name of time zone
SYNOPSIS
get_name()
......@@ -1030,15 +1030,15 @@ Time_zone_system::get_name() const
/*
Instance of this class represents UTC time zone. It uses system gmtime_r
function for conversions and is always available. It is used only for
my_time_t -> TIME conversions in various UTC_... functions, it is not
Instance of this class represents UTC time zone. It uses system gmtime_r
function for conversions and is always available. It is used only for
my_time_t -> TIME conversions in various UTC_... functions, it is not
intended for TIME -> my_time_t conversions and shouldn't be exposed to user.
*/
class Time_zone_utc : public Time_zone
class Time_zone_utc : public Time_zone
{
public:
virtual my_time_t TIME_to_gmt_sec(const TIME *t,
virtual my_time_t TIME_to_gmt_sec(const TIME *t,
bool *in_dst_time_gap) const;
virtual void gmt_sec_to_TIME(TIME *tmp, my_time_t t) const;
virtual const String * get_name() const;
......@@ -1047,45 +1047,45 @@ public:
/*
Convert UTC time from TIME representation to its my_time_t representation.
SYNOPSIS
TIME_to_gmt_sec()
t - pointer to TIME structure with local time
t - pointer to TIME structure with local time
in broken-down representation.
in_dst_time_gap - pointer to bool which is set to true if datetime
in_dst_time_gap - pointer to bool which is set to true if datetime
value passed doesn't really exist (i.e. falls into
spring time-gap) and is not touched otherwise.
DESCRIPTION
Since Time_zone_utc is used only internally for my_time_t -> TIME
conversions, this function of Time_zone interface is not implemented for
Since Time_zone_utc is used only internally for my_time_t -> TIME
conversions, this function of Time_zone interface is not implemented for
this class and should not be called.
RETURN VALUE
0
*/
my_time_t
my_time_t
Time_zone_utc::TIME_to_gmt_sec(const TIME *t, bool *in_dst_time_gap) const
{
/* Should be never called */
DBUG_ASSERT(0);
return 0;
}
/*
Converts time from UTC seconds since Epoch (my_time_t) representation
to broken-down representation (also in UTC).
SYNOPSIS
gmt_sec_to_TIME()
tmp - pointer to TIME structure to fill-in
t - my_time_t value to be converted
t - my_time_t value to be converted
NOTE
See note for apropriate Time_zone_system method.
*/
void
void
Time_zone_utc::gmt_sec_to_TIME(TIME *tmp, my_time_t t) const
{
struct tm tmp_tm;
......@@ -1098,15 +1098,15 @@ Time_zone_utc::gmt_sec_to_TIME(TIME *tmp, my_time_t t) const
/*
Get name of time zone
SYNOPSIS
get_name()
DESCRIPTION
Since Time_zone_utc is used only internally by SQL's UTC_* functions it
is not accessible directly, and hence this function of Time_zone
Since Time_zone_utc is used only internally by SQL's UTC_* functions it
is not accessible directly, and hence this function of Time_zone
interface is not implemented for this class and should not be called.
RETURN VALUE
0
*/
......@@ -1120,14 +1120,14 @@ Time_zone_utc::get_name() const
/*
Instance of this class represents some time zone which is
described in mysql.time_zone family of tables.
Instance of this class represents some time zone which is
described in mysql.time_zone family of tables.
*/
class Time_zone_db : public Time_zone
class Time_zone_db : public Time_zone
{
public:
Time_zone_db(TIME_ZONE_INFO *tz_info_arg, const String * tz_name_arg);
virtual my_time_t TIME_to_gmt_sec(const TIME *t,
virtual my_time_t TIME_to_gmt_sec(const TIME *t,
bool *in_dst_time_gap) const;
virtual void gmt_sec_to_TIME(TIME *tmp, my_time_t t) const;
virtual const String * get_name() const;
......@@ -1138,19 +1138,19 @@ private:
/*
Initializes object representing time zone described by mysql.time_zone
Initializes object representing time zone described by mysql.time_zone
tables.
SYNOPSIS
Time_zone_db()
tz_info_arg - pointer to TIME_ZONE_INFO structure which is filled
according to db or other time zone description
tz_info_arg - pointer to TIME_ZONE_INFO structure which is filled
according to db or other time zone description
(for example by my_tz_init()).
Several Time_zone_db instances can share one
Several Time_zone_db instances can share one
TIME_ZONE_INFO structure.
tz_name_arg - name of time zone.
*/
Time_zone_db::Time_zone_db(TIME_ZONE_INFO *tz_info_arg,
Time_zone_db::Time_zone_db(TIME_ZONE_INFO *tz_info_arg,
const String *tz_name_arg):
tz_info(tz_info_arg), tz_name(tz_name_arg)
{
......@@ -1158,25 +1158,25 @@ Time_zone_db::Time_zone_db(TIME_ZONE_INFO *tz_info_arg,
/*
Converts local time in time zone described from TIME
Converts local time in time zone described from TIME
representation to its my_time_t representation.
SYNOPSIS
TIME_to_gmt_sec()
t - pointer to TIME structure with local time
t - pointer to TIME structure with local time
in broken-down representation.
in_dst_time_gap - pointer to bool which is set to true if datetime
in_dst_time_gap - pointer to bool which is set to true if datetime
value passed doesn't really exist (i.e. falls into
spring time-gap) and is not touched otherwise.
DESCRIPTION
Please see ::TIME_to_gmt_sec for function description and
Please see ::TIME_to_gmt_sec for function description and
parameter restrictions.
RETURN VALUE
Corresponding my_time_t value or 0 in case of error
*/
my_time_t
my_time_t
Time_zone_db::TIME_to_gmt_sec(const TIME *t, bool *in_dst_time_gap) const
{
return ::TIME_to_gmt_sec(t, tz_info, in_dst_time_gap);
......@@ -1186,13 +1186,13 @@ Time_zone_db::TIME_to_gmt_sec(const TIME *t, bool *in_dst_time_gap) const
/*
Converts time from UTC seconds since Epoch (my_time_t) representation
to local time zone described in broken-down representation.
SYNOPSIS
gmt_sec_to_TIME()
tmp - pointer to TIME structure to fill-in
t - my_time_t value to be converted
t - my_time_t value to be converted
*/
void
void
Time_zone_db::gmt_sec_to_TIME(TIME *tmp, my_time_t t) const
{
::gmt_sec_to_TIME(tmp, t, tz_info);
......@@ -1201,7 +1201,7 @@ Time_zone_db::gmt_sec_to_TIME(TIME *tmp, my_time_t t) const
/*
Get name of time zone
SYNOPSIS
get_name()
......@@ -1216,18 +1216,18 @@ Time_zone_db::get_name() const
/*
Instance of this class represents time zone which
Instance of this class represents time zone which
was specified as offset from UTC.
*/
class Time_zone_offset : public Time_zone
class Time_zone_offset : public Time_zone
{
public:
Time_zone_offset(long tz_offset_arg);
virtual my_time_t TIME_to_gmt_sec(const TIME *t,
virtual my_time_t TIME_to_gmt_sec(const TIME *t,
bool *in_dst_time_gap) const;
virtual void gmt_sec_to_TIME(TIME *tmp, my_time_t t) const;
virtual const String * get_name() const;
/*
/*
This have to be public because we want to be able to access it from
my_offset_tzs_get_key() function
*/
......@@ -1241,10 +1241,10 @@ private:
/*
Initializes object representing time zone described by its offset from UTC.
SYNOPSIS
Time_zone_offset()
tz_offset_arg - offset from UTC in seconds.
tz_offset_arg - offset from UTC in seconds.
Positive for direction to east.
*/
Time_zone_offset::Time_zone_offset(long tz_offset_arg):
......@@ -1252,7 +1252,7 @@ Time_zone_offset::Time_zone_offset(long tz_offset_arg):
{
uint hours= abs((int)(offset / SECS_PER_HOUR));
uint minutes= abs((int)(offset % SECS_PER_HOUR / SECS_PER_MIN));
ulong length= my_snprintf(name_buff, sizeof(name_buff), "%s%02d:%02d",
ulong length= my_snprintf(name_buff, sizeof(name_buff), "%s%02d:%02d",
(offset>=0) ? "+" : "-", hours, minutes);
name.set(name_buff, length, &my_charset_latin1);
}
......@@ -1261,21 +1261,21 @@ Time_zone_offset::Time_zone_offset(long tz_offset_arg):
/*
Converts local time in time zone described as offset from UTC
from TIME representation to its my_time_t representation.
SYNOPSIS
TIME_to_gmt_sec()
t - pointer to TIME structure with local time
t - pointer to TIME structure with local time
in broken-down representation.
in_dst_time_gap - pointer to bool which should be set to true if
datetime value passed doesn't really exist
(i.e. falls into spring time-gap) and is not
in_dst_time_gap - pointer to bool which should be set to true if
datetime value passed doesn't really exist
(i.e. falls into spring time-gap) and is not
touched otherwise.
It is not really used in this class.
RETURN VALUE
Corresponding my_time_t value or 0 in case of error
*/
my_time_t
my_time_t
Time_zone_offset::TIME_to_gmt_sec(const TIME *t, bool *in_dst_time_gap) const
{
return sec_since_epoch(t->year, t->month, t->day,
......@@ -1286,15 +1286,15 @@ Time_zone_offset::TIME_to_gmt_sec(const TIME *t, bool *in_dst_time_gap) const
/*
Converts time from UTC seconds since Epoch (my_time_t) representation
to local time zone described as offset from UTC and in broken-down
to local time zone described as offset from UTC and in broken-down
representation.
SYNOPSIS
gmt_sec_to_TIME()
tmp - pointer to TIME structure to fill-in
t - my_time_t value to be converted
t - my_time_t value to be converted
*/
void
void
Time_zone_offset::gmt_sec_to_TIME(TIME *tmp, my_time_t t) const
{
sec_to_TIME(tmp, t, offset);
......@@ -1303,7 +1303,7 @@ Time_zone_offset::gmt_sec_to_TIME(TIME *tmp, my_time_t t) const
/*
Get name of time zone
SYNOPSIS
get_name()
......@@ -1327,10 +1327,10 @@ static HASH tz_names;
static HASH offset_tzs;
static MEM_ROOT tz_storage;
/*
/*
These mutex protects offset_tzs and tz_storage.
These protection needed only when we are trying to set
time zone which is specified as offset, and searching for existing
These protection needed only when we are trying to set
time zone which is specified as offset, and searching for existing
time zone in offset_tzs or creating if it didn't existed before in
tz_storage. So contention is low.
*/
......@@ -1344,7 +1344,7 @@ static bool tz_inited= 0;
static uint tz_leapcnt= 0;
static LS_INFO *tz_lsis= 0;
typedef struct st_tz_names_entry: public Sql_alloc
{
String name;
......@@ -1353,8 +1353,8 @@ typedef struct st_tz_names_entry: public Sql_alloc
/*
We are going to call both of these functions from C code so
they should obey C calling conventions.
We are going to call both of these functions from C code so
they should obey C calling conventions.
*/
extern "C" byte* my_tz_names_get_key(TZ_NAMES_ENTRY *entry, uint *length,
......@@ -1380,7 +1380,7 @@ extern "C" byte* my_offset_tzs_get_key(Time_zone_offset *entry, uint *length,
thd - current thread object
default_tzname - default time zone or 0 if none.
bootstrap - indicates whenever we are in bootstrap mode
DESCRIPTION
This function will init memory structures needed for time zone support,
it will register mandatory SYSTEM time zone in them. It will try to open
......@@ -1392,12 +1392,12 @@ extern "C" byte* my_offset_tzs_get_key(Time_zone_offset *entry, uint *length,
we are in bootstrap mode and won't load time zone descriptions unless someone
specifies default time zone which is supposedly stored in those tables.
It'll also set default time zone if it is specified.
RETURN VALUES
0 - ok
1 - Error
1 - Error
*/
my_bool
my_bool
my_tz_init(THD *org_thd, const char *default_tzname, my_bool bootstrap)
{
THD *thd;
......@@ -1449,15 +1449,15 @@ my_tz_init(THD *org_thd, const char *default_tzname, my_bool bootstrap)
sql_print_error("Fatal error: OOM while initializing time zones");
goto end_with_cleanup;
}
if (bootstrap)
{
/* If we are in bootstrap mode we should not load time zone tables */
return_val= 0;
goto end_with_setting_default_tz;
}
/*
/*
After this point all memory structures are inited and we even can live
without time zone description tables. Now try to load information about
leap seconds shared by all time zones.
......@@ -1469,7 +1469,7 @@ my_tz_init(THD *org_thd, const char *default_tzname, my_bool bootstrap)
tables.alias= tables.real_name= (char*)"time_zone_leap_second";
tables.lock_type= TL_READ;
tables.db= thd->db;
if (open_tables(thd, &tables, &not_used))
{
sql_print_error("Warning: Can't open time zone table: %s "
......@@ -1478,7 +1478,7 @@ my_tz_init(THD *org_thd, const char *default_tzname, my_bool bootstrap)
return_val= 0;
goto end_with_setting_default_tz;
}
lock_ptr= tables.table;
if (!(lock= mysql_lock_tables(thd, &lock_ptr, 1)))
{
......@@ -1486,7 +1486,7 @@ my_tz_init(THD *org_thd, const char *default_tzname, my_bool bootstrap)
thd->net.last_error);
goto end_with_cleanup;
}
/*
Now we are going to load leap seconds descriptions that are shared
......@@ -1501,11 +1501,11 @@ my_tz_init(THD *org_thd, const char *default_tzname, my_bool bootstrap)
"mysql.time_zone_leap_second table");
goto end_with_unlock;
}
table= tables.table;
table->file->index_init(0);
table->file->ha_index_init(0);
tz_leapcnt= 0;
res= table->file->index_first(table->record[0]);
while (!res)
......@@ -1514,10 +1514,10 @@ my_tz_init(THD *org_thd, const char *default_tzname, my_bool bootstrap)
{
sql_print_error("Fatal error: While loading mysql.time_zone_leap_second"
" table: too much leaps");
table->file->index_end();
table->file->ha_index_end();
goto end_with_unlock;
}
tz_lsis[tz_leapcnt].ls_trans= (my_time_t)table->field[0]->val_int();
tz_lsis[tz_leapcnt].ls_corr= (long)table->field[1]->val_int();
......@@ -1525,14 +1525,14 @@ my_tz_init(THD *org_thd, const char *default_tzname, my_bool bootstrap)
DBUG_PRINT("info",
("time_zone_leap_second table: tz_leapcnt=%u tt_time=%lld offset=%ld",
tz_leapcnt, (longlong)tz_lsis[tz_leapcnt-1].ls_trans,
tz_leapcnt, (longlong)tz_lsis[tz_leapcnt-1].ls_trans,
tz_lsis[tz_leapcnt-1].ls_corr));
res= table->file->index_next(table->record[0]);
}
table->file->index_end();
table->file->ha_index_end();
if (res != HA_ERR_END_OF_FILE)
{
sql_print_error("Fatal error: Error while loading "
......@@ -1543,10 +1543,10 @@ my_tz_init(THD *org_thd, const char *default_tzname, my_bool bootstrap)
/*
Loading of info about leap seconds succeeded
*/
return_val= 0;
end_with_unlock:
mysql_unlock_tables(thd, lock);
thd->version--; /* Force close to free memory */
......@@ -1563,9 +1563,9 @@ end_with_setting_default_tz:
return_val= 1;
}
}
end_with_cleanup:
/* if there were error free time zone describing structs */
if (return_val)
my_tz_free();
......@@ -1611,17 +1611,17 @@ void my_tz_free()
tz_load_from_db()
thd - current thread object
tz_name - name of time zone that should be loaded.
DESCRIPTION
This function will try to open system tables describing time zones
and to load information about time zone specified. It will also update
information in hash used for time zones lookup.
RETURN VALUES
Returns pointer to newly created Time_zone object or 0 in case of error.
*/
static Time_zone*
static Time_zone*
tz_load_from_db(THD *thd, const String *tz_name)
{
TABLE_LIST tables[4];
......@@ -1640,7 +1640,7 @@ tz_load_from_db(THD *thd, const String *tz_name)
char buff[MAX_FIELD_WIDTH];
String abbr(buff, sizeof(buff), &my_charset_latin1);
char *alloc_buff, *tz_name_buff;
/*
/*
Temporary arrays that are used for loading of data for filling
TIME_ZONE_INFO structure
*/
......@@ -1653,8 +1653,8 @@ tz_load_from_db(THD *thd, const String *tz_name)
uint not_used;
DBUG_ENTER("tz_load_from_db");
/* Prepare tz_info for loading also let us make copy of time zone name */
if (!(alloc_buff= alloc_root(&tz_storage, sizeof(TIME_ZONE_INFO) +
tz_name->length() + 1)))
......@@ -1670,7 +1670,7 @@ tz_load_from_db(THD *thd, const String *tz_name)
By writing zero to the end we guarantee that we can call ptr()
instead of c_ptr() for time zone name.
*/
strmake(tz_name_buff, tz_name->ptr(), tz_name->length());
strmake(tz_name_buff, tz_name->ptr(), tz_name->length());
/*
Open and lock time zone description tables
......@@ -1679,7 +1679,7 @@ tz_load_from_db(THD *thd, const String *tz_name)
db_length_save= thd->db_length;
thd->db= system_db_name;
thd->db_length= 5;
bzero((char*) &tables,sizeof(tables));
tables[0].alias= tables[0].real_name= (char*)"time_zone_name";
tables[1].alias= tables[1].real_name= (char*)"time_zone";
......@@ -1688,82 +1688,82 @@ tz_load_from_db(THD *thd, const String *tz_name)
tables[0].next= tables+1;
tables[1].next= tables+2;
tables[2].next= tables+3;
tables[0].lock_type= tables[1].lock_type= tables[2].lock_type=
tables[0].lock_type= tables[1].lock_type= tables[2].lock_type=
tables[3].lock_type= TL_READ;
tables[0].db= tables[1].db= tables[2].db= tables[3].db= thd->db;
if (open_tables(thd, tables, &not_used))
{
sql_print_error("Error: Can't open time zone tables: %s",
sql_print_error("Error: Can't open time zone tables: %s",
thd->net.last_error);
goto end;
}
lock_ptr[0]= tables[0].table;
lock_ptr[1]= tables[1].table;
lock_ptr[2]= tables[2].table;
lock_ptr[3]= tables[3].table;
if (!(lock= mysql_lock_tables(thd, lock_ptr, 4)))
{
sql_print_error("Error: Can't lock time zone tables: %s",
sql_print_error("Error: Can't lock time zone tables: %s",
thd->net.last_error);
goto end_with_close;
}
/*
Let us find out time zone id by its name (there is only one index
/*
Let us find out time zone id by its name (there is only one index
and it is specifically for this purpose).
*/
table= tables[0].table;
table->field[0]->store(tz_name->ptr(), tz_name->length(), &my_charset_latin1);
table->file->index_init(0);
table->file->ha_index_init(0);
if (table->file->index_read(table->record[0], (byte*)table->field[0]->ptr,
0, HA_READ_KEY_EXACT))
{
sql_print_error("Error: Can't find description of time zone.");
goto end_with_unlock;
}
tzid= table->field[1]->val_int();
table->file->index_end();
/*
table->file->ha_index_end();
/*
Now we need to lookup record in mysql.time_zone table in order to
understand whenever this timezone uses leap seconds (again we are
using the only index in this table).
*/
table= tables[1].table;
table->field[0]->store((longlong)tzid);
table->file->index_init(0);
table->file->ha_index_init(0);
if (table->file->index_read(table->record[0], (byte*)table->field[0]->ptr,
0, HA_READ_KEY_EXACT))
{
sql_print_error("Error: Can't find description of time zone.");
goto end_with_unlock;
}
/* If Uses_leap_seconds == 'Y' */
if (table->field[1]->val_int() == 1)
{
tz_info->leapcnt= tz_leapcnt;
tz_info->lsis= tz_lsis;
}
table->file->index_end();
/*
Now we will iterate through records for out time zone in
mysql.time_zone_transition_type table. Because we want records
only for our time zone guess what are we doing?
table->file->ha_index_end();
/*
Now we will iterate through records for out time zone in
mysql.time_zone_transition_type table. Because we want records
only for our time zone guess what are we doing?
Right - using special index.
*/
table= tables[3].table;
table->field[0]->store((longlong)tzid);
table->file->index_init(0);
table->file->ha_index_init(0);
// FIXME Is there any better approach than explicitly specifying 4 ???
res= table->file->index_read(table->record[0], (byte*)table->field[0]->ptr,
4, HA_READ_KEY_EXACT);
......@@ -1797,10 +1797,10 @@ tz_load_from_db(THD *thd, const String *tz_name)
tz_info->charcnt+= abbr.length();
chars[tz_info->charcnt]= 0;
tz_info->charcnt++;
DBUG_PRINT("info",
("time_zone_transition_type table: tz_id=%u tt_id=%u tt_gmtoff=%ld "
"abbr='%s' tt_isdst=%u", tzid, ttid, ttis[ttid].tt_gmtoff,
"abbr='%s' tt_isdst=%u", tzid, ttid, ttis[ttid].tt_gmtoff,
chars + ttis[ttid].tt_abbrind, ttis[ttid].tt_isdst));
#else
DBUG_PRINT("info",
......@@ -1810,13 +1810,13 @@ tz_load_from_db(THD *thd, const String *tz_name)
/* ttid is increasing because we are reading using index */
DBUG_ASSERT(ttid >= tz_info->typecnt);
tz_info->typecnt= ttid + 1;
res= table->file->index_next_same(table->record[0],
res= table->file->index_next_same(table->record[0],
(byte*)table->field[0]->ptr, 4);
}
if (res != HA_ERR_END_OF_FILE)
{
sql_print_error("Error while loading time zone description from "
......@@ -1824,18 +1824,18 @@ tz_load_from_db(THD *thd, const String *tz_name)
goto end_with_unlock;
}
table->file->index_end();
table->file->ha_index_end();
/*
At last we are doing the same thing for records in
mysql.time_zone_transition table. Here we additionaly need records
At last we are doing the same thing for records in
mysql.time_zone_transition table. Here we additionaly need records
in ascending order by index scan also satisfies us.
*/
table= tables[2].table;
table->field[0]->store((longlong)tzid);
table->file->index_init(0);
table->file->ha_index_init(0);
// FIXME Is there any better approach than explicitly specifying 4 ???
res= table->file->index_read(table->record[0], (byte*)table->field[0]->ptr,
4, HA_READ_KEY_EXACT);
......@@ -1858,7 +1858,7 @@ tz_load_from_db(THD *thd, const String *tz_name)
"bad transition type id");
goto end_with_unlock;
}
ats[tz_info->timecnt]= ttime;
types[tz_info->timecnt]= ttid;
tz_info->timecnt++;
......@@ -1866,12 +1866,12 @@ tz_load_from_db(THD *thd, const String *tz_name)
DBUG_PRINT("info",
("time_zone_transition table: tz_id=%u tt_time=%lld tt_id=%u",
tzid, (longlong)ttime, ttid));
res= table->file->index_next_same(table->record[0],
res= table->file->index_next_same(table->record[0],
(byte*)table->field[0]->ptr, 4);
}
/*
/*
We have to allow HA_ERR_KEY_NOT_FOUND because some time zones
for example UTC have no transitons.
*/
......@@ -1881,14 +1881,14 @@ tz_load_from_db(THD *thd, const String *tz_name)
"mysql.time_zone_transition table");
goto end_with_unlock;
}
table->file->index_end();
table->file->ha_index_end();
table= 0;
/*
Now we will allocate memory and init TIME_ZONE_INFO structure.
*/
if (!(alloc_buff= alloc_root(&tz_storage,
if (!(alloc_buff= alloc_root(&tz_storage,
ALIGN_SIZE(sizeof(my_time_t) *
tz_info->timecnt) +
ALIGN_SIZE(tz_info->timecnt) +
......@@ -1902,7 +1902,7 @@ tz_load_from_db(THD *thd, const String *tz_name)
goto end_with_unlock;
}
tz_info->ats= (my_time_t *)alloc_buff;
memcpy(tz_info->ats, ats, tz_info->timecnt * sizeof(my_time_t));
alloc_buff+= ALIGN_SIZE(sizeof(my_time_t) * tz_info->timecnt);
......@@ -1916,9 +1916,9 @@ tz_load_from_db(THD *thd, const String *tz_name)
#endif
tz_info->ttis= (TRAN_TYPE_INFO *)alloc_buff;
memcpy(tz_info->ttis, ttis, tz_info->typecnt * sizeof(TRAN_TYPE_INFO));
/*
Let us check how correct our time zone description and build
Let us check how correct our time zone description and build
reversed map. We don't check for tz->timecnt < 1 since it ok for GMT.
*/
if (tz_info->typecnt < 1)
......@@ -1931,12 +1931,12 @@ tz_load_from_db(THD *thd, const String *tz_name)
sql_print_error("Error: Unable to build mktime map for time zone");
goto end_with_unlock;
}
if (!(tmp_tzname= new (&tz_storage) TZ_NAMES_ENTRY()) ||
!(tmp_tzname->tz= new (&tz_storage) Time_zone_db(tz_info,
!(tmp_tzname->tz= new (&tz_storage) Time_zone_db(tz_info,
&(tmp_tzname->name))) ||
(tmp_tzname->name.set(tz_name_buff, tz_name->length(),
(tmp_tzname->name.set(tz_name_buff, tz_name->length(),
&my_charset_latin1),
my_hash_insert(&tz_names, (const byte *)tmp_tzname)))
{
......@@ -1948,17 +1948,17 @@ tz_load_from_db(THD *thd, const String *tz_name)
Loading of time zone succeeded
*/
return_val= tmp_tzname->tz;
end_with_unlock:
if (table)
table->file->index_end();
table->file->ha_index_end();
mysql_unlock_tables(thd, lock);
end_with_close:
close_thread_tables(thd);
end:
thd->db= db_save;
thd->db_length= db_length_save;
......@@ -1971,15 +1971,15 @@ end:
SYNOPSIS
str_to_offset()
str - pointer to string which contains offset
str - pointer to string which contains offset
length - length of string
offset - out parameter for storing found offset in seconds.
DESCRIPTION
This function parses string which contains time zone offset
in form similar to '+10:00' and converts found value to
This function parses string which contains time zone offset
in form similar to '+10:00' and converts found value to
seconds from UTC form (east is positive).
RETURN VALUE
0 - Ok
1 - String doesn't contain valid time zone offset
......@@ -1991,10 +1991,10 @@ str_to_offset(const char *str, uint length, long *offset)
my_bool negative;
ulong number_tmp;
long offset_tmp;
if (length < 4)
return 1;
if (*str == '+')
negative= 0;
else if (*str == '-')
......@@ -2010,13 +2010,13 @@ str_to_offset(const char *str, uint length, long *offset)
number_tmp= number_tmp*10 + *str - '0';
str++;
}
if (str + 1 >= end || *str != ':')
return 1;
str++;
offset_tmp = number_tmp * MINS_PER_HOUR; number_tmp= 0;
while (str < end && my_isdigit(&my_charset_latin1, *str))
{
number_tmp= number_tmp * 10 + *str - '0';
......@@ -2031,17 +2031,17 @@ str_to_offset(const char *str, uint length, long *offset)
if (negative)
offset_tmp= -offset_tmp;
/*
/*
Check if offset is in range prescribed by standard
(from -12:59 to 13:00).
*/
if (number_tmp > 59 || offset_tmp < -13 * SECS_PER_HOUR + 1 ||
offset_tmp > 13 * SECS_PER_HOUR)
return 1;
*offset= offset_tmp;
return 0;
}
......@@ -2056,56 +2056,56 @@ str_to_offset(const char *str, uint length, long *offset)
DESCRIPTION
This function checks if name is one of time zones described in db,
predefined SYSTEM time zone or valid time zone specification as
predefined SYSTEM time zone or valid time zone specification as
offset from UTC (In last case it will create proper Time_zone_offset
object if there were not any.). If name is ok it returns corresponding
Time_zone object.
Clients of this function are not responsible for releasing resources
occupied by returned Time_zone object so they can just forget pointers
Clients of this function are not responsible for releasing resources
occupied by returned Time_zone object so they can just forget pointers
to Time_zone object if they are not needed longer.
Other important property of this function: if some Time_zone found once
it will be for sure found later, so this function can also be used for
checking if proper Time_zone object exists (and if there will be error
it will be reported during first call).
If name pointer is 0 then this function returns 0 (this allows to pass 0
values as parameter without additional external check and this property
values as parameter without additional external check and this property
is used by @@time_zone variable handling code).
It will perform lookup in system tables (mysql.time_zone*) if needed.
RETURN VALUE
Pointer to corresponding Time_zone object. 0 - in case of bad time zone
Pointer to corresponding Time_zone object. 0 - in case of bad time zone
specification or other error.
*/
Time_zone *
Time_zone *
my_tz_find(THD *thd, const String * name)
{
TZ_NAMES_ENTRY *tmp_tzname;
Time_zone *result_tz= 0;
long offset;
DBUG_ENTER("my_tz_find");
DBUG_PRINT("enter", ("time zone name='%s'",
DBUG_PRINT("enter", ("time zone name='%s'",
name ? ((String *)name)->c_ptr() : "NULL"));
if (!name)
DBUG_RETURN(0);
VOID(pthread_mutex_lock(&tz_LOCK));
if (!str_to_offset(name->ptr(), name->length(), &offset))
{
if (!(result_tz= (Time_zone_offset *)hash_search(&offset_tzs,
(const byte *)&offset,
(const byte *)&offset,
sizeof(long))))
{
DBUG_PRINT("info", ("Creating new Time_zone_offset object"));
if (!(result_tz= new (&tz_storage) Time_zone_offset(offset)) ||
my_hash_insert(&offset_tzs, (const byte *) result_tz))
{
......@@ -2121,7 +2121,7 @@ my_tz_find(THD *thd, const String * name)
else
result_tz= tz_load_from_db(thd, name);
}
VOID(pthread_mutex_unlock(&tz_LOCK));
DBUG_RETURN(result_tz);
......@@ -2139,13 +2139,13 @@ my_tz_find(THD *thd, const String * name)
/*
Print info about time zone described by TIME_ZONE_INFO struct as
Print info about time zone described by TIME_ZONE_INFO struct as
SQL statements populating mysql.time_zone* tables.
SYNOPSIS
print_tz_as_sql()
tz_name - name of time zone
sp - structure describing time zone
sp - structure describing time zone
*/
void
print_tz_as_sql(const char* tz_name, const TIME_ZONE_INFO *sp)
......@@ -2153,7 +2153,7 @@ print_tz_as_sql(const char* tz_name, const TIME_ZONE_INFO *sp)
uint i;
/* Here we assume that all time zones have same leap correction tables */
printf("INSERT INTO time_zone (Use_leap_seconds) VALUES ('%s');\n",
printf("INSERT INTO time_zone (Use_leap_seconds) VALUES ('%s');\n",
sp->leapcnt ? "Y" : "N");
printf("SET @time_zone_id= LAST_INSERT_ID();\n");
printf("INSERT INTO time_zone_name (Name, Time_zone_id) VALUES \
......@@ -2168,13 +2168,13 @@ print_tz_as_sql(const char* tz_name, const TIME_ZONE_INFO *sp)
(uint)sp->types[i]);
printf(";\n");
}
printf("INSERT INTO time_zone_transition_type \
(Time_zone_id, Transition_type_id, Offset, Is_DST, Abbreviation) VALUES\n");
for (i= 0; i < sp->typecnt; i++)
printf("%s(@time_zone_id, %u, %ld, %d, '%s')\n", (i == 0 ? " " : ","), i,
sp->ttis[i].tt_gmtoff, sp->ttis[i].tt_isdst,
sp->ttis[i].tt_gmtoff, sp->ttis[i].tt_isdst,
sp->chars + sp->ttis[i].tt_abbrind);
printf(";\n");
}
......@@ -2186,25 +2186,25 @@ print_tz_as_sql(const char* tz_name, const TIME_ZONE_INFO *sp)
SYNOPSIS
print_tz_leaps_as_sql()
sp - structure describing time zone
sp - structure describing time zone
*/
void
print_tz_leaps_as_sql(const TIME_ZONE_INFO *sp)
{
uint i;
/*
We are assuming that there are only one list of leap seconds
/*
We are assuming that there are only one list of leap seconds
For all timezones.
*/
printf("TRUNCATE TABLE time_zone_leap_second;\n");
if (sp->leapcnt)
{
printf("INSERT INTO time_zone_leap_second \
(Transition_time, Correction) VALUES\n");
for (i= 0; i < sp->leapcnt; i++)
printf("%s(%ld, %ld)\n", (i == 0 ? " " : ","),
printf("%s(%ld, %ld)\n", (i == 0 ? " " : ","),
sp->lsis[i].ls_trans, sp->lsis[i].ls_corr);
printf(";\n");
}
......@@ -2214,7 +2214,7 @@ print_tz_leaps_as_sql(const TIME_ZONE_INFO *sp)
/*
Some variables used as temporary or as parameters
Some variables used as temporary or as parameters
in recursive scan_tz_dir() code.
*/
TIME_ZONE_INFO tz_info;
......@@ -2226,23 +2226,23 @@ char *root_name_end;
/*
Recursively scan zoneinfo directory and print all found time zone
descriptions as SQL.
SYNOPSIS
scan_tz_dir()
scan_tz_dir()
name_end - pointer to end of path to directory to be searched.
DESCRIPTION
This auxiliary recursive function also uses several global
This auxiliary recursive function also uses several global
variables as in parameters and for storing temporary values.
fullname - path to directory that should be scanned.
root_name_end - pointer to place in fullname where part with
root_name_end - pointer to place in fullname where part with
path to initial directory ends.
current_tz_id - last used time zone id
RETURN VALUE
0 - Ok, 1 - Fatal error
*/
my_bool
scan_tz_dir(char * name_end)
......@@ -2250,12 +2250,12 @@ scan_tz_dir(char * name_end)
MY_DIR *cur_dir;
char *name_end_tmp;
uint i;
if (!(cur_dir= my_dir(fullname, MYF(MY_WANT_STAT))))
return 1;
name_end= strmake(name_end, "/", FN_REFLEN - (name_end - fullname));
for (i= 0; i < cur_dir->number_off_files; i++)
{
if (cur_dir->dir_entry[i].name[0] != '.')
......@@ -2311,19 +2311,19 @@ main(int argc, char **argv)
if (argc == 2)
{
root_name_end= strmake(fullname, argv[1], FN_REFLEN);
printf("TRUNCATE TABLE time_zone;\n");
printf("TRUNCATE TABLE time_zone_name;\n");
printf("TRUNCATE TABLE time_zone_transition;\n");
printf("TRUNCATE TABLE time_zone_transition_type;\n");
if (scan_tz_dir(root_name_end))
{
fprintf(stderr, "There were fatal errors during processing "
"of zoneinfo directory\n");
return 1;
}
printf("ALTER TABLE time_zone_transition "
"ORDER BY Time_zone_id, Transition_time;\n");
printf("ALTER TABLE time_zone_transition_type "
......@@ -2332,7 +2332,7 @@ main(int argc, char **argv)
else
{
init_alloc_root(&tz_storage, 32768, 0);
if (strcmp(argv[1], "--leap") == 0)
{
if (tz_load(argv[2], &tz_info, &tz_storage))
......@@ -2351,7 +2351,7 @@ main(int argc, char **argv)
}
print_tz_as_sql(argv[2], &tz_info);
}
free_root(&tz_storage, MYF(0));
}
......@@ -2375,7 +2375,7 @@ main(int argc, char **argv)
#ifndef TYPE_BIT
#define TYPE_BIT(type) (sizeof (type) * CHAR_BIT)
#endif
#endif
#ifndef TYPE_SIGNED
#define TYPE_SIGNED(type) (((type) -1) < 0)
......@@ -2415,7 +2415,7 @@ main(int argc, char **argv)
/* let us set some well known timezone */
setenv("TZ", "MET", 1);
tzset();
/* Some initial time zone related system info */
printf("time_t: %s %u bit\n", TYPE_SIGNED(time_t) ? "signed" : "unsigned",
(uint)TYPE_BIT(time_t));
......@@ -2424,13 +2424,13 @@ main(int argc, char **argv)
t= -100;
localtime_negative= test(localtime_r(&t, &tmp) != 0);
printf("localtime_r %s negative params \
(time_t=%d is %d-%d-%d %d:%d:%d)\n",
(time_t=%d is %d-%d-%d %d:%d:%d)\n",
(localtime_negative ? "supports" : "doesn't support"), (int)t,
TM_YEAR_BASE + tmp.tm_year, tmp.tm_mon + 1, tmp.tm_mday,
TM_YEAR_BASE + tmp.tm_year, tmp.tm_mon + 1, tmp.tm_mday,
tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
printf("mktime %s negative results (%d)\n",
(t == mktime(&tmp) ? "doesn't support" : "supports"),
(t == mktime(&tmp) ? "doesn't support" : "supports"),
(int)mktime(&tmp));
}
......@@ -2439,13 +2439,13 @@ main(int argc, char **argv)
t= mktime(&tmp);
printf("mktime returns %s for spring time gap (%d)\n",
(t != (time_t)-1 ? "something" : "error"), (int)t);
tmp.tm_year= 103; tmp.tm_mon= 8; tmp.tm_mday= 1;
tmp.tm_hour= 0; tmp.tm_min= 0; tmp.tm_sec= 0; tmp.tm_isdst= 0;
t= mktime(&tmp);
printf("mktime returns %s for non existing date (%d)\n",
(t != (time_t)-1 ? "something" : "error"), (int)t);
tmp.tm_year= 103; tmp.tm_mon= 8; tmp.tm_mday= 1;
tmp.tm_hour= 25; tmp.tm_min=0; tmp.tm_sec=0; tmp.tm_isdst=1;
t= mktime(&tmp);
......@@ -2462,13 +2462,13 @@ main(int argc, char **argv)
tmp.tm_hour= 2; tmp.tm_isdst= -1;
t1= mktime(&tmp);
printf("mktime is %s (%d %d)\n",
(t == t1 ? "determenistic" : "is non-determenistic"),
(t == t1 ? "determenistic" : "is non-determenistic"),
(int)t, (int)t1);
/* Let us load time zone description */
str_end= strmake(fullname, TZDIR, FN_REFLEN);
strmake(str_end, "/MET", FN_REFLEN - (str_end - fullname));
if (tz_load(fullname, &tz_info, &tz_storage))
{
printf("Unable to load time zone info from '%s'\n", fullname);
......@@ -2477,7 +2477,7 @@ main(int argc, char **argv)
}
printf("Testing our implementation\n");
if (TYPE_SIGNED(time_t) && localtime_negative)
{
for (t= -40000; t < 20000; t++)
......@@ -2493,12 +2493,12 @@ main(int argc, char **argv)
}
printf("gmt_sec_to_TIME = localtime for time_t in [-40000,20000) range\n");
}
for (t= 1000000000; t < 1100000000; t+= 13)
{
localtime_r(&t,&tmp);
gmt_sec_to_TIME(&time_tmp, (my_time_t)t, &tz_info);
if (!is_equal_TIME_tm(&time_tmp, &tmp))
{
printf("Problem with time_t = %d\n", (int)t);
......@@ -2509,14 +2509,14 @@ main(int argc, char **argv)
printf("gmt_sec_to_TIME = localtime for time_t in [1000000000,1100000000) range\n");
init_time();
/*
Be careful here! my_system_gmt_sec doesn't fully handle unnormalized
dates.
*/
for (time_tmp.year= 1980; time_tmp.year < 2010; time_tmp.year++)
for (time_tmp.month= 1; time_tmp.month < 13; time_tmp.month++)
for (time_tmp.day= 1;
for (time_tmp.day= 1;
time_tmp.day < mon_lengths[isleap(time_tmp.year)][time_tmp.month-1];
time_tmp.day++)
for (time_tmp.hour= 0; time_tmp.hour < 24; time_tmp.hour++)
......@@ -2527,11 +2527,11 @@ main(int argc, char **argv)
t1= (time_t)TIME_to_gmt_sec(&time_tmp, &tz_info, &not_used_2);
if (t != t1)
{
/*
/*
We need special handling during autumn since my_system_gmt_sec
prefers greater time_t values (in MET) for ambiguity.
And BTW that is a bug which should be fixed !!!
*/
*/
tmp.tm_year= time_tmp.year - TM_YEAR_BASE;
tmp.tm_mon= time_tmp.month - 1;
tmp.tm_mday= time_tmp.day;
......@@ -2544,17 +2544,17 @@ main(int argc, char **argv)
if (t1 == t2)
continue;
printf("Problem: %u/%u/%u %u:%u:%u with times t=%d, t1=%d\n",
time_tmp.year, time_tmp.month, time_tmp.day,
time_tmp.hour, time_tmp.minute, time_tmp.second,
(int)t,(int)t1);
free_root(&tz_storage, MYF(0));
return 1;
}
}
printf("TIME_to_gmt_sec = my_system_gmt_sec for test range\n");
free_root(&tz_storage, MYF(0));
......
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