~drizzle-trunk/drizzle/development : revision 673.3.34

39

/* Structure describing leap-second corrections. */

40

typedef struct lsinfo

41

{

42

my_time_t ls_trans; // Transition time

42

time_t ls_trans; // Transition time

43

long ls_corr; // Correction to apply

44

} LS_INFO;

45

46

/*

47

Structure with information describing ranges of my_time_t shifted to local

48

time (my_time_t + offset). Used for local DRIZZLE_TIME -> my_time_t conversion.

47

Structure with information describing ranges of time_t shifted to local

48

time (time_t + offset). Used for local DRIZZLE_TIME -> time_t conversion.

49

See comments for TIME_to_gmt_sec() for more info.

50

*/

51

typedef struct revtinfo

65

uint32_t timecnt; // Number of transitions between time types

66

uint32_t typecnt; // Number of local time types

67

uint32_t charcnt; // Number of characters used for abbreviations

68

uint32_t revcnt; // Number of transition descr. for TIME->my_time_t conversion

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uint32_t revcnt; // Number of transition descr. for TIME->time_t conversion

69

/* The following are dynamical arrays are allocated in MEM_ROOT */

70

my_time_t *ats; // Times of transitions between time types

70

time_t *ats; // Times of transitions between time types

71

unsigned char *types; // Local time types for transitions

72

TRAN_TYPE_INFO *ttis; // Local time types descriptions

73

/* Storage for local time types abbreviations. They are stored as ASCIIZ */

78

*/

79

LS_INFO *lsis;

80

/*

81

Starting points and descriptions of shifted my_time_t (my_time_t + offset)

82

ranges on which shifted my_time_t -> my_time_t mapping is linear or undefined.

83

Used for tm -> my_time_t conversion.

81

Starting points and descriptions of shifted time_t (time_t + offset)

82

ranges on which shifted time_t -> time_t mapping is linear or undefined.

83

Used for tm -> time_t conversion.

84

*/

85

my_time_t *revts;

85

time_t *revts;

86

REVT_INFO *revtis;

87

/*

88

Time type which is used for times smaller than first transition or if

116

117

118

/*

119

Converts time from my_time_t representation (seconds in UTC since Epoch)

119

Converts time from time_t representation (seconds in UTC since Epoch)

120

to broken down representation using given local time zone offset.

121

122

SYNOPSIS

123

sec_to_TIME()

124

tmp - pointer to structure for broken down representation

125

t - my_time_t value to be converted

125

t - time_t value to be converted

126

offset - local time zone offset

127

128

DESCRIPTION

129

Convert my_time_t with offset to DRIZZLE_TIME struct. Differs from timesub

129

Convert time_t with offset to DRIZZLE_TIME struct. Differs from timesub

130

(from elsie code) because doesn't contain any leap correction and

131

TM_GMTOFF and is_dst setting and contains some MySQL specific

132

initialization. Funny but with removing of these we almost have

133

glibc's offtime function.

134

*/

135

static void

136

sec_to_TIME(DRIZZLE_TIME * tmp, my_time_t t, long offset)

136

sec_to_TIME(DRIZZLE_TIME * tmp, time_t t, long offset)

137

{

138

long days;

139

long rem;

146

147

/*

148

We do this as separate step after dividing t, because this

149

allows us handle times near my_time_t bounds without overflows.

149

allows us handle times near time_t bounds without overflows.

150

*/

151

rem+= offset;

152

while (rem < 0)

196

197

198

/*

199

Find time range wich contains given my_time_t value

199

Find time range wich contains given time_t value

200

201

SYNOPSIS

202

find_time_range()

203

t - my_time_t value for which we looking for range

203

t - time_t value for which we looking for range

204

range_boundaries - sorted array of range starts.

205

higher_bound - number of ranges

206

207

DESCRIPTION

208

Performs binary search for range which contains given my_time_t value.

209

It has sense if number of ranges is greater than zero and my_time_t value

208

Performs binary search for range which contains given time_t value.

209

It has sense if number of ranges is greater than zero and time_t value

210

is greater or equal than beginning of first range. It also assumes that

211

t belongs to some range specified or end of last is MY_TIME_T_MAX.

211

t belongs to some range specified.

212

213

With this localtime_r on real data may takes less time than with linear

214

search (I've seen 30% speed up).

217

Index of range to which t belongs

218

*/

219

static uint

220

find_time_range(my_time_t t, const my_time_t *range_boundaries,

220

find_time_range(time_t t, const time_t *range_boundaries,

221

uint32_t higher_bound)

222

{

223

uint32_t i, lower_bound= 0;

246

}

247

248

/*

249

Find local time transition for given my_time_t.

249

Find local time transition for given time_t.

250

251

SYNOPSIS

252

find_transition_type()

253

t - my_time_t value to be converted

253

t - time_t value to be converted

254

sp - pointer to struct with time zone description

255

256

RETURN VALUE

257

Pointer to structure in time zone description describing

258

local time type for given my_time_t.

258

local time type for given time_t.

259

*/

260

static

261

const TRAN_TYPE_INFO *

262

find_transition_type(my_time_t t, const TIME_ZONE_INFO *sp)

262

find_transition_type(time_t t, const TIME_ZONE_INFO *sp)

263

{

264

if (unlikely(sp->timecnt == 0 || t < sp->ats[0]))

265

{

280

281

282

/*

283

Converts time in my_time_t representation (seconds in UTC since Epoch) to

283

Converts time in time_t representation (seconds in UTC since Epoch) to

284

broken down DRIZZLE_TIME representation in local time zone.

285

286

SYNOPSIS

287

gmt_sec_to_TIME()

288

tmp - pointer to structure for broken down represenatation

289

sec_in_utc - my_time_t value to be converted

289

sec_in_utc - time_t value to be converted

290

sp - pointer to struct with time zone description

291

292

TODO

296

(60th and 61st second, look how we calculate them as "hit" in this

297

function).

298

Under realistic assumptions about frequency of transitions the same array

299

can be used fot DRIZZLE_TIME -> my_time_t conversion. For this we need to

299

can be used for DRIZZLE_TIME -> time_t conversion. For this we need to

300

implement tweaked binary search which will take into account that some

301

DRIZZLE_TIME has two matching my_time_t ranges and some of them have none.

301

DRIZZLE_TIME has two matching time_t ranges and some of them have none.

302

*/

303

static void

304

gmt_sec_to_TIME(DRIZZLE_TIME *tmp, time_t sec_in_utc, const TIME_ZONE_INFO *sp)

357

358

/*

359

Converts local time in broken down representation to local

360

time zone analog of my_time_t represenation.

360

time zone analog of time_t represenation.

361

362

SYNOPSIS

363

sec_since_epoch()

364

year, mon, mday, hour, min, sec - broken down representation.

365

366

DESCRIPTION

367

Converts time in broken down representation to my_time_t representation

367

Converts time in broken down representation to time_t representation

368

ignoring time zone. Note that we cannot convert back some valid _local_

369

times near ends of my_time_t range because of my_time_t overflow. But we

369

times near ends of time_t range because of time_t overflow. But we

370

ignore this fact now since MySQL will never pass such argument.

371

372

RETURN VALUE

373

Seconds since epoch time representation.

374

*/

375

static my_time_t

375

static time_t

376

sec_since_epoch(int year, int mon, int mday, int hour, int min ,int sec)

377

{

378

/* Guard against my_time_t overflow(on system with 32 bit my_time_t) */

378

/* Guard against time_t overflow (on system with 32 bit time_t) */

379

assert(!(year == TIMESTAMP_MAX_YEAR && mon == 1 && mday > 17));

380

#ifndef WE_WANT_TO_HANDLE_UNORMALIZED_DATES

381

/*

403

}

404

405

/*

406

Converts local time in broken down DRIZZLE_TIME representation to my_time_t

406

Converts local time in broken down DRIZZLE_TIME representation to time_t

407

representation.

408

409

SYNOPSIS

421

has two answers it will give the smaller one

422

- If we are in spring time gap then it will return

423

beginning of the gap

424

- It can give wrong results near the ends of my_time_t due to

424

- It can give wrong results near the ends of time_t due to

425

overflows, but we are safe since in MySQL we will never

426

call this function for such dates (its restriction for year

427

between 1970 and 2038 gives us several days of reserve).

445

446

We use completely different approach. It is better since it is both

447

faster than iterative implementations and fully determenistic. If you

448

look at my_time_t to DRIZZLE_TIME conversion then you'll find that it consist

448

look at time_t to DRIZZLE_TIME conversion then you'll find that it consist

449

of two steps:

450

The first is calculating shifted my_time_t value and the second - TIME

451

calculation from shifted my_time_t value (well it is a bit simplified

452

picture). The part in which we are interested in is my_time_t -> shifted

453

my_time_t conversion. It is piecewise linear function which is defined

450

The first is calculating shifted time_t value and the second - TIME

451

calculation from shifted time_t value (well it is a bit simplified

452

picture). The part in which we are interested in is time_t -> shifted

453

time_t conversion. It is piecewise linear function which is defined

454

by combination of transition times as break points and times offset

455

as changing function parameter. The possible inverse function for this

456

converison would be ambiguos but with MySQL's restrictions we can use

457

some function which is the same as inverse function on unambigiuos

458

ranges and coincides with one of branches of inverse function in

459

other ranges. Thus we just need to build table which will determine

460

this shifted my_time_t -> my_time_t conversion similar to existing

461

(my_time_t -> shifted my_time_t table). We do this in

460

this shifted time_t -> time_t conversion similar to existing

461

(time_t -> shifted time_t table). We do this in

462

prepare_tz_info function.

463

464

TODO

474

Seconds in UTC since Epoch.

475

0 in case of error.

476

*/

477

static my_time_t

477

static time_t

478

TIME_to_gmt_sec(const DRIZZLE_TIME *t, const TIME_ZONE_INFO *sp,

479

bool *in_dst_time_gap)

480

{

481

my_time_t local_t;

481

time_t local_t;

482

uint32_t saved_seconds;

483

uint32_t i;

484

int shift= 0;

494

saved_seconds= t->second;

495

496

/*

497

NOTE: to convert full my_time_t range we do a shift of the

498

boundary dates here to avoid overflow of my_time_t.

497

NOTE: to convert full time_t range we do a shift of the

498

boundary dates here to avoid overflow of time_t.

499

We use alike approach in my_system_gmt_sec().

500

501

However in that function we also have to take into account

526

if (local_t < sp->revts[0] || local_t > sp->revts[sp->revcnt])

527

{

528

/*

529

This means that source time can't be represented as my_time_t due to

530

limited my_time_t range.

529

This means that source time can't be represented as time_t due to

530

limited time_t range.

531

*/

532

return(0);

533

}

542

*/

543

if (shift)

544

{

545

if (local_t > (my_time_t) (TIMESTAMP_MAX_VALUE - shift * SECS_PER_DAY +

546

sp->revtis[i].rt_offset - saved_seconds))

545

if (local_t > (time_t) (TIMESTAMP_MAX_VALUE - shift * SECS_PER_DAY +

546

sp->revtis[i].rt_offset - saved_seconds))

547

{

548

return(0); /* my_time_t overflow */

548

return(0); /* time_t overflow */

549

}

550

local_t+= shift * SECS_PER_DAY;

551

}

555

/*

556

Oops! We are in spring time gap.

557

May be we should return error here?

558

Now we are returning my_time_t value corresponding to the

558

Now we are returning time_t value corresponding to the

559

beginning of the gap.

560

*/

561

*in_dst_time_gap= 1;

598

{

599

public:

600

Time_zone_system() {} /* Remove gcc warning */

601

virtual my_time_t TIME_to_gmt_sec(const DRIZZLE_TIME *t,

601

virtual time_t TIME_to_gmt_sec(const DRIZZLE_TIME *t,

602

bool *in_dst_time_gap) const;

603

virtual void gmt_sec_to_TIME(DRIZZLE_TIME *tmp, my_time_t t) const;

603

virtual void gmt_sec_to_TIME(DRIZZLE_TIME *tmp, time_t t) const;

604

virtual const String * get_name() const;

605

};

606

607

608

/*

609

Converts local time in system time zone in DRIZZLE_TIME representation

610

to its my_time_t representation.

610

to its time_t representation.

611

612

SYNOPSIS

613

TIME_to_gmt_sec()

619

620

DESCRIPTION

621

This method uses system function (localtime_r()) for conversion

622

local time in system time zone in DRIZZLE_TIME structure to its my_time_t

622

local time in system time zone in DRIZZLE_TIME structure to its time_t

623

representation. Unlike the same function for Time_zone_db class

624

it it won't handle unnormalized input properly. Still it will

625

return lowest possible my_time_t in case of ambiguity or if we

625

return lowest possible time_t in case of ambiguity or if we

626

provide time corresponding to the time-gap.

627

628

You should call init_time() function before using this function.

629

630

RETURN VALUE

631

Corresponding my_time_t value or 0 in case of error

631

Corresponding time_t value or 0 in case of error

632

*/

633

my_time_t

633

time_t

634

Time_zone_system::TIME_to_gmt_sec(const DRIZZLE_TIME *t, bool *in_dst_time_gap) const

635

{

636

long not_used;

639

640

641

/*

642

Converts time from UTC seconds since Epoch (my_time_t) representation

642

Converts time from UTC seconds since Epoch (time_t) representation

643

to system local time zone broken-down representation.

644

645

SYNOPSIS

646

gmt_sec_to_TIME()

647

tmp - pointer to DRIZZLE_TIME structure to fill-in

648

t - my_time_t value to be converted

648

t - time_t value to be converted

649

650

NOTE

651

We assume that value passed to this function will fit into time_t range

655

the 1902 easily.

656

*/

657

void

658

Time_zone_system::gmt_sec_to_TIME(DRIZZLE_TIME *tmp, my_time_t t) const

658

Time_zone_system::gmt_sec_to_TIME(DRIZZLE_TIME *tmp, time_t t) const

659

{

660

struct tm tmp_tm;

661

time_t tmp_t= (time_t)t;

685

/*

686

Instance of this class represents UTC time zone. It uses system gmtime_r

687

function for conversions and is always available. It is used only for

688

my_time_t -> DRIZZLE_TIME conversions in various UTC_... functions, it is not

689

intended for DRIZZLE_TIME -> my_time_t conversions and shouldn't be exposed to user.

688

time_t -> DRIZZLE_TIME conversions in various UTC_... functions, it is not

689

intended for DRIZZLE_TIME -> time_t conversions and shouldn't be exposed to user.

690

*/

691

class Time_zone_utc : public Time_zone

692

{

693

public:

694

Time_zone_utc() {} /* Remove gcc warning */

695

virtual my_time_t TIME_to_gmt_sec(const DRIZZLE_TIME *t,

695

virtual time_t TIME_to_gmt_sec(const DRIZZLE_TIME *t,

696

bool *in_dst_time_gap) const;

697

virtual void gmt_sec_to_TIME(DRIZZLE_TIME *tmp, my_time_t t) const;

697

virtual void gmt_sec_to_TIME(DRIZZLE_TIME *tmp, time_t t) const;

698

virtual const String * get_name() const;

699

};

700

701

702

/*

703

Convert UTC time from DRIZZLE_TIME representation to its my_time_t representation.

703

Convert UTC time from DRIZZLE_TIME representation to its time_t representation.

704

705

SYNOPSIS

706

TIME_to_gmt_sec()

711

spring time-gap) and is not touched otherwise.

712

713

DESCRIPTION

714

Since Time_zone_utc is used only internally for my_time_t -> TIME

714

Since Time_zone_utc is used only internally for time_t -> TIME

715

conversions, this function of Time_zone interface is not implemented for

716

this class and should not be called.

717

718

RETURN VALUE

719

0

720

*/

721

my_time_t

721

time_t

722

Time_zone_utc::TIME_to_gmt_sec(const DRIZZLE_TIME *t __attribute__((unused)),

723

bool *in_dst_time_gap __attribute__((unused))) const

724

{

729

730

731

/*

732

Converts time from UTC seconds since Epoch (my_time_t) representation

732

Converts time from UTC seconds since Epoch (time_t) representation

733

to broken-down representation (also in UTC).

734

735

SYNOPSIS

736

gmt_sec_to_TIME()

737

tmp - pointer to DRIZZLE_TIME structure to fill-in

738

t - my_time_t value to be converted

738

t - time_t value to be converted

739

740

NOTE

741

See note for apropriate Time_zone_system method.

742

*/

743

void

744

Time_zone_utc::gmt_sec_to_TIME(DRIZZLE_TIME *tmp, my_time_t t) const

744

Time_zone_utc::gmt_sec_to_TIME(DRIZZLE_TIME *tmp, time_t t) const

745

{

746

struct tm tmp_tm;

747

time_t tmp_t= (time_t)t;

782

{

783

public:

784

Time_zone_db(TIME_ZONE_INFO *tz_info_arg, const String * tz_name_arg);

785

virtual my_time_t TIME_to_gmt_sec(const DRIZZLE_TIME *t,

785

virtual time_t TIME_to_gmt_sec(const DRIZZLE_TIME *t,

786

bool *in_dst_time_gap) const;

787

virtual void gmt_sec_to_TIME(DRIZZLE_TIME *tmp, my_time_t t) const;

787

virtual void gmt_sec_to_TIME(DRIZZLE_TIME *tmp, time_t t) const;

788

virtual const String * get_name() const;

789

private:

790

TIME_ZONE_INFO *tz_info;

814

815

/*

816

Converts local time in time zone described from TIME

817

representation to its my_time_t representation.

817

representation to its time_t representation.

818

819

SYNOPSIS

820

TIME_to_gmt_sec()

829

parameter restrictions.

830

831

RETURN VALUE

832

Corresponding my_time_t value or 0 in case of error

832

Corresponding time_t value or 0 in case of error

833

*/

834

my_time_t

834

time_t

835

Time_zone_db::TIME_to_gmt_sec(const DRIZZLE_TIME *t, bool *in_dst_time_gap) const

836

{

837

return ::TIME_to_gmt_sec(t, tz_info, in_dst_time_gap);

839

840

841

/*

842

Converts time from UTC seconds since Epoch (my_time_t) representation

842

Converts time from UTC seconds since Epoch (time_t) representation

843

to local time zone described in broken-down representation.

844

845

SYNOPSIS

846

gmt_sec_to_TIME()

847

tmp - pointer to DRIZZLE_TIME structure to fill-in

848

t - my_time_t value to be converted

848

t - time_t value to be converted

849

*/

850

void

851

Time_zone_db::gmt_sec_to_TIME(DRIZZLE_TIME *tmp, my_time_t t) const

851

Time_zone_db::gmt_sec_to_TIME(DRIZZLE_TIME *tmp, time_t t) const

852

{

853

::gmt_sec_to_TIME(tmp, t, tz_info);

854

}

878

{

879

public:

880

Time_zone_offset(long tz_offset_arg);

881

virtual my_time_t TIME_to_gmt_sec(const DRIZZLE_TIME *t,

881

virtual time_t TIME_to_gmt_sec(const DRIZZLE_TIME *t,

882

bool *in_dst_time_gap) const;

883

virtual void gmt_sec_to_TIME(DRIZZLE_TIME *tmp, my_time_t t) const;

883

virtual void gmt_sec_to_TIME(DRIZZLE_TIME *tmp, time_t t) const;

884

virtual const String * get_name() const;

885

/*

886

This have to be public because we want to be able to access it from

915

916

/*

917

Converts local time in time zone described as offset from UTC

918

from DRIZZLE_TIME representation to its my_time_t representation.

918

from DRIZZLE_TIME representation to its time_t representation.

919

920

SYNOPSIS

921

TIME_to_gmt_sec()

928

It is not really used in this class.

929

930

RETURN VALUE

931

Corresponding my_time_t value or 0 in case of error

931

Corresponding time_t value or 0 in case of error

932

*/

933

my_time_t

933

time_t

934

Time_zone_offset::TIME_to_gmt_sec(const DRIZZLE_TIME *t,

935

bool *in_dst_time_gap __attribute__((unused))) const

936

{

937

my_time_t local_t;

937

time_t local_t;

938

int shift= 0;

939

940

/*

946

947

/*

948

Do a temporary shift of the boundary dates to avoid

949

overflow of my_time_t if the time value is near it's

949

overflow of time_t if the time value is near it's

950

maximum range

951

*/

952

if ((t->year == TIMESTAMP_MAX_YEAR) && (t->month == 1) && t->day > 4)

971

972

973

/*

974

Converts time from UTC seconds since Epoch (my_time_t) representation

974

Converts time from UTC seconds since Epoch (time_t) representation

975

to local time zone described as offset from UTC and in broken-down

976

representation.

977

978

SYNOPSIS

979

gmt_sec_to_TIME()

980

tmp - pointer to DRIZZLE_TIME structure to fill-in

981

t - my_time_t value to be converted

981

t - time_t value to be converted

982

*/

983

void

984

Time_zone_offset::gmt_sec_to_TIME(DRIZZLE_TIME *tmp, my_time_t t) const

984

Time_zone_offset::gmt_sec_to_TIME(DRIZZLE_TIME *tmp, time_t t) const

985

{

986

sec_to_TIME(tmp, t, offset);

987

}