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cosmopolitan/third_party/sqlite3/date.c
Justine Tunney b0df6c1fce
Implement proper time zone support 
Cosmopolitan now supports 104 time zones. They're embedded inside any
binary that links the localtime() function. Doing so adds about 100kb
to the binary size. This change also gets time zones working properly
on Windows for the first time. It's not needed to have /etc/localtime
exist on Windows, since we can get this information from WIN32. We're
also now updated to the latest version of Paul Eggert's TZ library.
2024-05-04 23:06:37 -07:00

1358 lines
36 KiB
C
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/*
** 2003 October 31
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C functions that implement date and time
** functions for SQLite.
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** SQLite processes all times and dates as julian day numbers. The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system.
**
** 1970-01-01 00:00:00 is JD 2440587.5
** 2000-01-01 00:00:00 is JD 2451544.5
**
** This implementation requires years to be expressed as a 4-digit number
** which means that only dates between 0000-01-01 and 9999-12-31 can
** be represented, even though julian day numbers allow a much wider
** range of dates.
**
** The Gregorian calendar system is used for all dates and times,
** even those that predate the Gregorian calendar. Historians usually
** use the julian calendar for dates prior to 1582-10-15 and for some
** dates afterwards, depending on locale. Beware of this difference.
**
** The conversion algorithms are implemented based on descriptions
** in the following text:
**
** Jean Meeus
** Astronomical Algorithms, 2nd Edition, 1998
** ISBN 0-943396-61-1
** Willmann-Bell, Inc
** Richmond, Virginia (USA)
*/
#include "libc/assert.h"
#include "libc/calls/weirdtypes.h"
#include "libc/mem/mem.h"
#include "libc/time.h"
#include "third_party/sqlite3/sqliteInt.h"
#ifndef SQLITE_OMIT_DATETIME_FUNCS
/*
** The MSVC CRT on Windows CE may not have a localtime() function.
** So declare a substitute. The substitute function itself is
** defined in "os_win.c".
*/
#if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \
(!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)
struct tm *__cdecl localtime(const time_t *);
#endif
/*
** A structure for holding a single date and time.
*/
typedef struct DateTime DateTime;
struct DateTime {
sqlite3_int64 iJD; /* The julian day number times 86400000 */
int Y, M, D; /* Year, month, and day */
int h, m; /* Hour and minutes */
int tz; /* Timezone offset in minutes */
double s; /* Seconds */
char validJD; /* True (1) if iJD is valid */
char rawS; /* Raw numeric value stored in s */
char validYMD; /* True (1) if Y,M,D are valid */
char validHMS; /* True (1) if h,m,s are valid */
char validTZ; /* True (1) if tz is valid */
char tzSet; /* Timezone was set explicitly */
char isError; /* An overflow has occurred */
};
/*
** Convert zDate into one or more integers according to the conversion
** specifier zFormat.
**
** zFormat[] contains 4 characters for each integer converted, except for
** the last integer which is specified by three characters. The meaning
** of a four-character format specifiers ABCD is:
**
** A: number of digits to convert. Always "2" or "4".
** B: minimum value. Always "0" or "1".
** C: maximum value, decoded as:
** a: 12
** b: 14
** c: 24
** d: 31
** e: 59
** f: 9999
** D: the separator character, or \000 to indicate this is the
** last number to convert.
**
** Example: To translate an ISO-8601 date YYYY-MM-DD, the format would
** be "40f-21a-20c". The "40f-" indicates the 4-digit year followed by "-".
** The "21a-" indicates the 2-digit month followed by "-". The "20c" indicates
** the 2-digit day which is the last integer in the set.
**
** The function returns the number of successful conversions.
*/
static int getDigits(const char *zDate, const char *zFormat, ...){
/* The aMx[] array translates the 3rd character of each format
** spec into a max size: a b c d e f */
static const u16 aMx[] = { 12, 14, 24, 31, 59, 9999 };
va_list ap;
int cnt = 0;
char nextC;
va_start(ap, zFormat);
do{
char N = zFormat[0] - '0';
char min = zFormat[1] - '0';
int val = 0;
u16 max;
assert( zFormat[2]>='a' && zFormat[2]<='f' );
max = aMx[zFormat[2] - 'a'];
nextC = zFormat[3];
val = 0;
while( N-- ){
if( !sqlite3Isdigit(*zDate) ){
goto end_getDigits;
}
val = val*10 + *zDate - '0';
zDate++;
}
if( val<(int)min || val>(int)max || (nextC!=0 && nextC!=*zDate) ){
goto end_getDigits;
}
*va_arg(ap,int*) = val;
zDate++;
cnt++;
zFormat += 4;
}while( nextC );
end_getDigits:
va_end(ap);
return cnt;
}
/*
** Parse a timezone extension on the end of a date-time.
** The extension is of the form:
**
** (+/-)HH:MM
**
** Or the "zulu" notation:
**
** Z
**
** If the parse is successful, write the number of minutes
** of change in p->tz and return 0. If a parser error occurs,
** return non-zero.
**
** A missing specifier is not considered an error.
*/
static int parseTimezone(const char *zDate, DateTime *p){
int sgn = 0;
int nHr, nMn;
int c;
while( sqlite3Isspace(*zDate) ){ zDate++; }
p->tz = 0;
c = *zDate;
if( c=='-' ){
sgn = -1;
}else if( c=='+' ){
sgn = +1;
}else if( c=='Z' || c=='z' ){
zDate++;
goto zulu_time;
}else{
return c!=0;
}
zDate++;
if( getDigits(zDate, "20b:20e", &nHr, &nMn)!=2 ){
return 1;
}
zDate += 5;
p->tz = sgn*(nMn + nHr*60);
zulu_time:
while( sqlite3Isspace(*zDate) ){ zDate++; }
p->tzSet = 1;
return *zDate!=0;
}
/*
** Parse times of the form HH:MM or HH:MM:SS or HH:MM:SS.FFFF.
** The HH, MM, and SS must each be exactly 2 digits. The
** fractional seconds FFFF can be one or more digits.
**
** Return 1 if there is a parsing error and 0 on success.
*/
static int parseHhMmSs(const char *zDate, DateTime *p){
int h, m, s;
double ms = 0.0;
if( getDigits(zDate, "20c:20e", &h, &m)!=2 ){
return 1;
}
zDate += 5;
if( *zDate==':' ){
zDate++;
if( getDigits(zDate, "20e", &s)!=1 ){
return 1;
}
zDate += 2;
if( *zDate=='.' && sqlite3Isdigit(zDate[1]) ){
double rScale = 1.0;
zDate++;
while( sqlite3Isdigit(*zDate) ){
ms = ms*10.0 + *zDate - '0';
rScale *= 10.0;
zDate++;
}
ms /= rScale;
}
}else{
s = 0;
}
p->validJD = 0;
p->rawS = 0;
p->validHMS = 1;
p->h = h;
p->m = m;
p->s = s + ms;
if( parseTimezone(zDate, p) ) return 1;
p->validTZ = (p->tz!=0)?1:0;
return 0;
}
/*
** Put the DateTime object into its error state.
*/
static void datetimeError(DateTime *p){
memset(p, 0, sizeof(*p));
p->isError = 1;
}
/*
** Convert from YYYY-MM-DD HH:MM:SS to julian day. We always assume
** that the YYYY-MM-DD is according to the Gregorian calendar.
**
** Reference: Meeus page 61
*/
static void computeJD(DateTime *p){
int Y, M, D, A, B, X1, X2;
if( p->validJD ) return;
if( p->validYMD ){
Y = p->Y;
M = p->M;
D = p->D;
}else{
Y = 2000; /* If no YMD specified, assume 2000-Jan-01 */
M = 1;
D = 1;
}
if( Y<-4713 || Y>9999 || p->rawS ){
datetimeError(p);
return;
}
if( M<=2 ){
Y--;
M += 12;
}
A = Y/100;
B = 2 - A + (A/4);
X1 = 36525*(Y+4716)/100;
X2 = 306001*(M+1)/10000;
p->iJD = (sqlite3_int64)((X1 + X2 + D + B - 1524.5 ) * 86400000);
p->validJD = 1;
if( p->validHMS ){
p->iJD += p->h*3600000 + p->m*60000 + (sqlite3_int64)(p->s*1000 + 0.5);
if( p->validTZ ){
p->iJD -= p->tz*60000;
p->validYMD = 0;
p->validHMS = 0;
p->validTZ = 0;
}
}
}
/*
** Parse dates of the form
**
** YYYY-MM-DD HH:MM:SS.FFF
** YYYY-MM-DD HH:MM:SS
** YYYY-MM-DD HH:MM
** YYYY-MM-DD
**
** Write the result into the DateTime structure and return 0
** on success and 1 if the input string is not a well-formed
** date.
*/
static int parseYyyyMmDd(const char *zDate, DateTime *p){
int Y, M, D, neg;
if( zDate[0]=='-' ){
zDate++;
neg = 1;
}else{
neg = 0;
}
if( getDigits(zDate, "40f-21a-21d", &Y, &M, &D)!=3 ){
return 1;
}
zDate += 10;
while( sqlite3Isspace(*zDate) || 'T'==*(u8*)zDate ){ zDate++; }
if( parseHhMmSs(zDate, p)==0 ){
/* We got the time */
}else if( *zDate==0 ){
p->validHMS = 0;
}else{
return 1;
}
p->validJD = 0;
p->validYMD = 1;
p->Y = neg ? -Y : Y;
p->M = M;
p->D = D;
if( p->validTZ ){
computeJD(p);
}
return 0;
}
/*
** Set the time to the current time reported by the VFS.
**
** Return the number of errors.
*/
static int setDateTimeToCurrent(sqlite3_context *context, DateTime *p){
p->iJD = sqlite3StmtCurrentTime(context);
if( p->iJD>0 ){
p->validJD = 1;
return 0;
}else{
return 1;
}
}
/*
** Input "r" is a numeric quantity which might be a julian day number,
** or the number of seconds since 1970. If the value if r is within
** range of a julian day number, install it as such and set validJD.
** If the value is a valid unix timestamp, put it in p->s and set p->rawS.
*/
static void setRawDateNumber(DateTime *p, double r){
p->s = r;
p->rawS = 1;
if( r>=0.0 && r<5373484.5 ){
p->iJD = (sqlite3_int64)(r*86400000.0 + 0.5);
p->validJD = 1;
}
}
/*
** Attempt to parse the given string into a julian day number. Return
** the number of errors.
**
** The following are acceptable forms for the input string:
**
** YYYY-MM-DD HH:MM:SS.FFF +/-HH:MM
** DDDD.DD
** now
**
** In the first form, the +/-HH:MM is always optional. The fractional
** seconds extension (the ".FFF") is optional. The seconds portion
** (":SS.FFF") is option. The year and date can be omitted as long
** as there is a time string. The time string can be omitted as long
** as there is a year and date.
*/
static int parseDateOrTime(
sqlite3_context *context,
const char *zDate,
DateTime *p
){
double r;
if( parseYyyyMmDd(zDate,p)==0 ){
return 0;
}else if( parseHhMmSs(zDate, p)==0 ){
return 0;
}else if( sqlite3StrICmp(zDate,"now")==0 && sqlite3NotPureFunc(context) ){
return setDateTimeToCurrent(context, p);
}else if( sqlite3AtoF(zDate, &r, sqlite3Strlen30(zDate), SQLITE_UTF8)>0 ){
setRawDateNumber(p, r);
return 0;
}
return 1;
}
/* The julian day number for 9999-12-31 23:59:59.999 is 5373484.4999999.
** Multiplying this by 86400000 gives 464269060799999 as the maximum value
** for DateTime.iJD.
**
** But some older compilers (ex: gcc 4.2.1 on older Macs) cannot deal with
** such a large integer literal, so we have to encode it.
*/
#define INT_464269060799999 ((((i64)0x1a640)<<32)|0x1072fdff)
/*
** Return TRUE if the given julian day number is within range.
**
** The input is the JulianDay times 86400000.
*/
static int validJulianDay(sqlite3_int64 iJD){
return iJD>=0 && iJD<=INT_464269060799999;
}
/*
** Compute the Year, Month, and Day from the julian day number.
*/
static void computeYMD(DateTime *p){
int Z, A, B, C, D, E, X1;
if( p->validYMD ) return;
if( !p->validJD ){
p->Y = 2000;
p->M = 1;
p->D = 1;
}else if( !validJulianDay(p->iJD) ){
datetimeError(p);
return;
}else{
Z = (int)((p->iJD + 43200000)/86400000);
A = (int)((Z - 1867216.25)/36524.25);
A = Z + 1 + A - (A/4);
B = A + 1524;
C = (int)((B - 122.1)/365.25);
D = (36525*(C&32767))/100;
E = (int)((B-D)/30.6001);
X1 = (int)(30.6001*E);
p->D = B - D - X1;
p->M = E<14 ? E-1 : E-13;
p->Y = p->M>2 ? C - 4716 : C - 4715;
}
p->validYMD = 1;
}
/*
** Compute the Hour, Minute, and Seconds from the julian day number.
*/
static void computeHMS(DateTime *p){
int s;
if( p->validHMS ) return;
computeJD(p);
s = (int)((p->iJD + 43200000) % 86400000);
p->s = s/1000.0;
s = (int)p->s;
p->s -= s;
p->h = s/3600;
s -= p->h*3600;
p->m = s/60;
p->s += s - p->m*60;
p->rawS = 0;
p->validHMS = 1;
}
/*
** Compute both YMD and HMS
*/
static void computeYMD_HMS(DateTime *p){
computeYMD(p);
computeHMS(p);
}
/*
** Clear the YMD and HMS and the TZ
*/
static void clearYMD_HMS_TZ(DateTime *p){
p->validYMD = 0;
p->validHMS = 0;
p->validTZ = 0;
}
#ifndef SQLITE_OMIT_LOCALTIME
/*
** On recent Windows platforms, the localtime_s() function is available
** as part of the "Secure CRT". It is essentially equivalent to
** localtime_r() available under most POSIX platforms, except that the
** order of the parameters is reversed.
**
** See http://msdn.microsoft.com/en-us/library/a442x3ye(VS.80).aspx.
**
** If the user has not indicated to use localtime_r() or localtime_s()
** already, check for an MSVC build environment that provides
** localtime_s().
*/
#if !HAVE_LOCALTIME_R && !HAVE_LOCALTIME_S \
&& defined(_MSC_VER) && defined(_CRT_INSECURE_DEPRECATE)
#undef HAVE_LOCALTIME_S
#define HAVE_LOCALTIME_S 1
#endif
/*
** The following routine implements the rough equivalent of localtime_r()
** using whatever operating-system specific localtime facility that
** is available. This routine returns 0 on success and
** non-zero on any kind of error.
**
** If the sqlite3GlobalConfig.bLocaltimeFault variable is non-zero then this
** routine will always fail. If bLocaltimeFault is nonzero and
** sqlite3GlobalConfig.xAltLocaltime is not NULL, then xAltLocaltime() is
** invoked in place of the OS-defined localtime() function.
**
** EVIDENCE-OF: R-62172-00036 In this implementation, the standard C
** library function localtime_r() is used to assist in the calculation of
** local time.
*/
static int osLocaltime(time_t *t, struct tm *pTm){
int rc;
#if !HAVE_LOCALTIME_R && !HAVE_LOCALTIME_S
struct tm *pX;
#if SQLITE_THREADSAFE>0
sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
sqlite3_mutex_enter(mutex);
pX = localtime(t);
#ifndef SQLITE_UNTESTABLE
if( sqlite3GlobalConfig.bLocaltimeFault ){
if( sqlite3GlobalConfig.xAltLocaltime!=0
&& 0==sqlite3GlobalConfig.xAltLocaltime((const void*)t,(void*)pTm)
){
pX = pTm;
}else{
pX = 0;
}
}
#endif
if( pX ) *pTm = *pX;
#if SQLITE_THREADSAFE>0
sqlite3_mutex_leave(mutex);
#endif
rc = pX==0;
#else
#ifndef SQLITE_UNTESTABLE
if( sqlite3GlobalConfig.bLocaltimeFault ){
if( sqlite3GlobalConfig.xAltLocaltime!=0 ){
return sqlite3GlobalConfig.xAltLocaltime((const void*)t,(void*)pTm);
}else{
return 1;
}
}
#endif
#if HAVE_LOCALTIME_R
rc = localtime_r(t, pTm)==0;
#else
rc = localtime_s(pTm, t);
#endif /* HAVE_LOCALTIME_R */
#endif /* HAVE_LOCALTIME_R || HAVE_LOCALTIME_S */
return rc;
}
#endif /* SQLITE_OMIT_LOCALTIME */
#ifndef SQLITE_OMIT_LOCALTIME
/*
** Assuming the input DateTime is UTC, move it to its localtime equivalent.
*/
static int toLocaltime(
DateTime *p, /* Date at which to calculate offset */
sqlite3_context *pCtx /* Write error here if one occurs */
){
time_t t;
struct tm sLocal;
int iYearDiff;
/* Initialize the contents of sLocal to avoid a compiler warning. */
memset(&sLocal, 0, sizeof(sLocal));
computeJD(p);
if( p->iJD<2108667600*(i64)100000 /* 1970-01-01 */
|| p->iJD>2130141456*(i64)100000 /* 2038-01-18 */
){
/* EVIDENCE-OF: R-55269-29598 The localtime_r() C function normally only
** works for years between 1970 and 2037. For dates outside this range,
** SQLite attempts to map the year into an equivalent year within this
** range, do the calculation, then map the year back.
*/
DateTime x = *p;
computeYMD_HMS(&x);
iYearDiff = (2000 + x.Y%4) - x.Y;
x.Y += iYearDiff;
x.validJD = 0;
computeJD(&x);
t = (time_t)(x.iJD/1000 - 21086676*(i64)10000);
}else{
iYearDiff = 0;
t = (time_t)(p->iJD/1000 - 21086676*(i64)10000);
}
if( osLocaltime(&t, &sLocal) ){
sqlite3_result_error(pCtx, "local time unavailable", -1);
return SQLITE_ERROR;
}
p->Y = sLocal.tm_year + 1900 - iYearDiff;
p->M = sLocal.tm_mon + 1;
p->D = sLocal.tm_mday;
p->h = sLocal.tm_hour;
p->m = sLocal.tm_min;
p->s = sLocal.tm_sec + (p->iJD%1000)*0.001;
p->validYMD = 1;
p->validHMS = 1;
p->validJD = 0;
p->rawS = 0;
p->validTZ = 0;
p->isError = 0;
return SQLITE_OK;
}
#endif /* SQLITE_OMIT_LOCALTIME */
/*
** The following table defines various date transformations of the form
**
** 'NNN days'
**
** Where NNN is an arbitrary floating-point number and "days" can be one
** of several units of time.
*/
static const struct {
u8 nName; /* Length of the name */
char zName[7]; /* Name of the transformation */
float rLimit; /* Maximum NNN value for this transform */
float rXform; /* Constant used for this transform */
} aXformType[] = {
{ 6, "second", 4.6427e+14, 1.0 },
{ 6, "minute", 7.7379e+12, 60.0 },
{ 4, "hour", 1.2897e+11, 3600.0 },
{ 3, "day", 5373485.0, 86400.0 },
{ 5, "month", 176546.0, 2592000.0 },
{ 4, "year", 14713.0, 31536000.0 },
};
/*
** Process a modifier to a date-time stamp. The modifiers are
** as follows:
**
** NNN days
** NNN hours
** NNN minutes
** NNN.NNNN seconds
** NNN months
** NNN years
** start of month
** start of year
** start of week
** start of day
** weekday N
** unixepoch
** localtime
** utc
**
** Return 0 on success and 1 if there is any kind of error. If the error
** is in a system call (i.e. localtime()), then an error message is written
** to context pCtx. If the error is an unrecognized modifier, no error is
** written to pCtx.
*/
static int parseModifier(
sqlite3_context *pCtx, /* Function context */
const char *z, /* The text of the modifier */
int n, /* Length of zMod in bytes */
DateTime *p, /* The date/time value to be modified */
int idx /* Parameter index of the modifier */
){
int rc = 1;
double r;
switch(sqlite3UpperToLower[(u8)z[0]] ){
case 'a': {
/*
** auto
**
** If rawS is available, then interpret as a julian day number, or
** a unix timestamp, depending on its magnitude.
*/
if( sqlite3_stricmp(z, "auto")==0 ){
if( idx>1 ) return 1; /* IMP: R-33611-57934 */
if( !p->rawS || p->validJD ){
rc = 0;
p->rawS = 0;
}else if( p->s>=-21086676*(i64)10000 /* -4713-11-24 12:00:00 */
&& p->s<=(25340230*(i64)10000)+799 /* 9999-12-31 23:59:59 */
){
r = p->s*1000.0 + 210866760000000.0;
clearYMD_HMS_TZ(p);
p->iJD = (sqlite3_int64)(r + 0.5);
p->validJD = 1;
p->rawS = 0;
rc = 0;
}
}
break;
}
case 'j': {
/*
** julianday
**
** Always interpret the prior number as a julian-day value. If this
** is not the first modifier, or if the prior argument is not a numeric
** value in the allowed range of julian day numbers understood by
** SQLite (0..5373484.5) then the result will be NULL.
*/
if( sqlite3_stricmp(z, "julianday")==0 ){
if( idx>1 ) return 1; /* IMP: R-31176-64601 */
if( p->validJD && p->rawS ){
rc = 0;
p->rawS = 0;
}
}
break;
}
#ifndef SQLITE_OMIT_LOCALTIME
case 'l': {
/* localtime
**
** Assuming the current time value is UTC (a.k.a. GMT), shift it to
** show local time.
*/
if( sqlite3_stricmp(z, "localtime")==0 && sqlite3NotPureFunc(pCtx) ){
rc = toLocaltime(p, pCtx);
}
break;
}
#endif
case 'u': {
/*
** unixepoch
**
** Treat the current value of p->s as the number of
** seconds since 1970. Convert to a real julian day number.
*/
if( sqlite3_stricmp(z, "unixepoch")==0 && p->rawS ){
if( idx>1 ) return 1; /* IMP: R-49255-55373 */
r = p->s*1000.0 + 210866760000000.0;
if( r>=0.0 && r<464269060800000.0 ){
clearYMD_HMS_TZ(p);
p->iJD = (sqlite3_int64)(r + 0.5);
p->validJD = 1;
p->rawS = 0;
rc = 0;
}
}
#ifndef SQLITE_OMIT_LOCALTIME
else if( sqlite3_stricmp(z, "utc")==0 && sqlite3NotPureFunc(pCtx) ){
if( p->tzSet==0 ){
i64 iOrigJD; /* Original localtime */
i64 iGuess; /* Guess at the corresponding utc time */
int cnt = 0; /* Safety to prevent infinite loop */
int iErr; /* Guess is off by this much */
computeJD(p);
iGuess = iOrigJD = p->iJD;
iErr = 0;
do{
DateTime new;
memset(&new, 0, sizeof(new));
iGuess -= iErr;
new.iJD = iGuess;
new.validJD = 1;
rc = toLocaltime(&new, pCtx);
if( rc ) return rc;
computeJD(&new);
iErr = new.iJD - iOrigJD;
}while( iErr && cnt++<3 );
memset(p, 0, sizeof(*p));
p->iJD = iGuess;
p->validJD = 1;
p->tzSet = 1;
}
rc = SQLITE_OK;
}
#endif
break;
}
case 'w': {
/*
** weekday N
**
** Move the date to the same time on the next occurrence of
** weekday N where 0==Sunday, 1==Monday, and so forth. If the
** date is already on the appropriate weekday, this is a no-op.
*/
if( sqlite3_strnicmp(z, "weekday ", 8)==0
&& sqlite3AtoF(&z[8], &r, sqlite3Strlen30(&z[8]), SQLITE_UTF8)>0
&& r>=0.0 && r<7.0 && (n=(int)r)==r ){
sqlite3_int64 Z;
computeYMD_HMS(p);
p->validTZ = 0;
p->validJD = 0;
computeJD(p);
Z = ((p->iJD + 129600000)/86400000) % 7;
if( Z>n ) Z -= 7;
p->iJD += (n - Z)*86400000;
clearYMD_HMS_TZ(p);
rc = 0;
}
break;
}
case 's': {
/*
** start of TTTTT
**
** Move the date backwards to the beginning of the current day,
** or month or year.
*/
if( sqlite3_strnicmp(z, "start of ", 9)!=0 ) break;
if( !p->validJD && !p->validYMD && !p->validHMS ) break;
z += 9;
computeYMD(p);
p->validHMS = 1;
p->h = p->m = 0;
p->s = 0.0;
p->rawS = 0;
p->validTZ = 0;
p->validJD = 0;
if( sqlite3_stricmp(z,"month")==0 ){
p->D = 1;
rc = 0;
}else if( sqlite3_stricmp(z,"year")==0 ){
p->M = 1;
p->D = 1;
rc = 0;
}else if( sqlite3_stricmp(z,"day")==0 ){
rc = 0;
}
break;
}
case '+':
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9': {
double rRounder;
int i;
for(n=1; z[n] && z[n]!=':' && !sqlite3Isspace(z[n]); n++){}
if( sqlite3AtoF(z, &r, n, SQLITE_UTF8)<=0 ){
rc = 1;
break;
}
if( z[n]==':' ){
/* A modifier of the form (+|-)HH:MM:SS.FFF adds (or subtracts) the
** specified number of hours, minutes, seconds, and fractional seconds
** to the time. The ".FFF" may be omitted. The ":SS.FFF" may be
** omitted.
*/
const char *z2 = z;
DateTime tx;
sqlite3_int64 day;
if( !sqlite3Isdigit(*z2) ) z2++;
memset(&tx, 0, sizeof(tx));
if( parseHhMmSs(z2, &tx) ) break;
computeJD(&tx);
tx.iJD -= 43200000;
day = tx.iJD/86400000;
tx.iJD -= day*86400000;
if( z[0]=='-' ) tx.iJD = -tx.iJD;
computeJD(p);
clearYMD_HMS_TZ(p);
p->iJD += tx.iJD;
rc = 0;
break;
}
/* If control reaches this point, it means the transformation is
** one of the forms like "+NNN days". */
z += n;
while( sqlite3Isspace(*z) ) z++;
n = sqlite3Strlen30(z);
if( n>10 || n<3 ) break;
if( sqlite3UpperToLower[(u8)z[n-1]]=='s' ) n--;
computeJD(p);
rc = 1;
rRounder = r<0 ? -0.5 : +0.5;
for(i=0; i<ArraySize(aXformType); i++){
if( aXformType[i].nName==n
&& sqlite3_strnicmp(aXformType[i].zName, z, n)==0
&& r>-aXformType[i].rLimit && r<aXformType[i].rLimit
){
switch( i ){
case 4: { /* Special processing to add months */
int x;
assert( strcmp(aXformType[i].zName,"month")==0 );
computeYMD_HMS(p);
p->M += (int)r;
x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12;
p->Y += x;
p->M -= x*12;
p->validJD = 0;
r -= (int)r;
break;
}
case 5: { /* Special processing to add years */
int y = (int)r;
assert( strcmp(aXformType[i].zName,"year")==0 );
computeYMD_HMS(p);
p->Y += y;
p->validJD = 0;
r -= (int)r;
break;
}
}
computeJD(p);
p->iJD += (sqlite3_int64)(r*1000.0*aXformType[i].rXform + rRounder);
rc = 0;
break;
}
}
clearYMD_HMS_TZ(p);
break;
}
default: {
break;
}
}
return rc;
}
/*
** Process time function arguments. argv[0] is a date-time stamp.
** argv[1] and following are modifiers. Parse them all and write
** the resulting time into the DateTime structure p. Return 0
** on success and 1 if there are any errors.
**
** If there are zero parameters (if even argv[0] is undefined)
** then assume a default value of "now" for argv[0].
*/
static int isDate(
sqlite3_context *context,
int argc,
sqlite3_value **argv,
DateTime *p
){
int i, n;
const unsigned char *z;
int eType;
memset(p, 0, sizeof(*p));
if( argc==0 ){
if( !sqlite3NotPureFunc(context) ) return 1;
return setDateTimeToCurrent(context, p);
}
if( (eType = sqlite3_value_type(argv[0]))==SQLITE_FLOAT
|| eType==SQLITE_INTEGER ){
setRawDateNumber(p, sqlite3_value_double(argv[0]));
}else{
z = sqlite3_value_text(argv[0]);
if( !z || parseDateOrTime(context, (char*)z, p) ){
return 1;
}
}
for(i=1; i<argc; i++){
z = sqlite3_value_text(argv[i]);
n = sqlite3_value_bytes(argv[i]);
if( z==0 || parseModifier(context, (char*)z, n, p, i) ) return 1;
}
computeJD(p);
if( p->isError || !validJulianDay(p->iJD) ) return 1;
return 0;
}
/*
** The following routines implement the various date and time functions
** of SQLite.
*/
/*
** julianday( TIMESTRING, MOD, MOD, ...)
**
** Return the julian day number of the date specified in the arguments
*/
static void juliandayFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
DateTime x;
if( isDate(context, argc, argv, &x)==0 ){
computeJD(&x);
sqlite3_result_double(context, x.iJD/86400000.0);
}
}
/*
** unixepoch( TIMESTRING, MOD, MOD, ...)
**
** Return the number of seconds (including fractional seconds) since
** the unix epoch of 1970-01-01 00:00:00 GMT.
*/
static void unixepochFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
DateTime x;
if( isDate(context, argc, argv, &x)==0 ){
computeJD(&x);
sqlite3_result_int64(context, x.iJD/1000 - 21086676*(i64)10000);
}
}
/*
** datetime( TIMESTRING, MOD, MOD, ...)
**
** Return YYYY-MM-DD HH:MM:SS
*/
static void datetimeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
DateTime x;
if( isDate(context, argc, argv, &x)==0 ){
int Y, s;
char zBuf[24];
computeYMD_HMS(&x);
Y = x.Y;
if( Y<0 ) Y = -Y;
zBuf[1] = '0' + (Y/1000)%10;
zBuf[2] = '0' + (Y/100)%10;
zBuf[3] = '0' + (Y/10)%10;
zBuf[4] = '0' + (Y)%10;
zBuf[5] = '-';
zBuf[6] = '0' + (x.M/10)%10;
zBuf[7] = '0' + (x.M)%10;
zBuf[8] = '-';
zBuf[9] = '0' + (x.D/10)%10;
zBuf[10] = '0' + (x.D)%10;
zBuf[11] = ' ';
zBuf[12] = '0' + (x.h/10)%10;
zBuf[13] = '0' + (x.h)%10;
zBuf[14] = ':';
zBuf[15] = '0' + (x.m/10)%10;
zBuf[16] = '0' + (x.m)%10;
zBuf[17] = ':';
s = (int)x.s;
zBuf[18] = '0' + (s/10)%10;
zBuf[19] = '0' + (s)%10;
zBuf[20] = 0;
if( x.Y<0 ){
zBuf[0] = '-';
sqlite3_result_text(context, zBuf, 20, SQLITE_TRANSIENT);
}else{
sqlite3_result_text(context, &zBuf[1], 19, SQLITE_TRANSIENT);
}
}
}
/*
** time( TIMESTRING, MOD, MOD, ...)
**
** Return HH:MM:SS
*/
static void timeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
DateTime x;
if( isDate(context, argc, argv, &x)==0 ){
int s;
char zBuf[16];
computeHMS(&x);
zBuf[0] = '0' + (x.h/10)%10;
zBuf[1] = '0' + (x.h)%10;
zBuf[2] = ':';
zBuf[3] = '0' + (x.m/10)%10;
zBuf[4] = '0' + (x.m)%10;
zBuf[5] = ':';
s = (int)x.s;
zBuf[6] = '0' + (s/10)%10;
zBuf[7] = '0' + (s)%10;
zBuf[8] = 0;
sqlite3_result_text(context, zBuf, 8, SQLITE_TRANSIENT);
}
}
/*
** date( TIMESTRING, MOD, MOD, ...)
**
** Return YYYY-MM-DD
*/
static void dateFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
DateTime x;
if( isDate(context, argc, argv, &x)==0 ){
int Y;
char zBuf[16];
computeYMD(&x);
Y = x.Y;
if( Y<0 ) Y = -Y;
zBuf[1] = '0' + (Y/1000)%10;
zBuf[2] = '0' + (Y/100)%10;
zBuf[3] = '0' + (Y/10)%10;
zBuf[4] = '0' + (Y)%10;
zBuf[5] = '-';
zBuf[6] = '0' + (x.M/10)%10;
zBuf[7] = '0' + (x.M)%10;
zBuf[8] = '-';
zBuf[9] = '0' + (x.D/10)%10;
zBuf[10] = '0' + (x.D)%10;
zBuf[11] = 0;
if( x.Y<0 ){
zBuf[0] = '-';
sqlite3_result_text(context, zBuf, 11, SQLITE_TRANSIENT);
}else{
sqlite3_result_text(context, &zBuf[1], 10, SQLITE_TRANSIENT);
}
}
}
/*
** strftime( FORMAT, TIMESTRING, MOD, MOD, ...)
**
** Return a string described by FORMAT. Conversions as follows:
**
** %d day of month
** %f ** fractional seconds SS.SSS
** %H hour 00-24
** %j day of year 000-366
** %J ** julian day number
** %m month 01-12
** %M minute 00-59
** %s seconds since 1970-01-01
** %S seconds 00-59
** %w day of week 0-6 sunday==0
** %W week of year 00-53
** %Y year 0000-9999
** %% %
*/
static void strftimeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
DateTime x;
size_t i,j;
sqlite3 *db;
const char *zFmt;
sqlite3_str sRes;
if( argc==0 ) return;
zFmt = (const char*)sqlite3_value_text(argv[0]);
if( zFmt==0 || isDate(context, argc-1, argv+1, &x) ) return;
db = sqlite3_context_db_handle(context);
sqlite3StrAccumInit(&sRes, 0, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]);
computeJD(&x);
computeYMD_HMS(&x);
for(i=j=0; zFmt[i]; i++){
if( zFmt[i]!='%' ) continue;
if( j<i ) sqlite3_str_append(&sRes, zFmt+j, (int)(i-j));
i++;
j = i + 1;
switch( zFmt[i] ){
case 'd': {
sqlite3_str_appendf(&sRes, "%02d", x.D);
break;
}
case 'f': {
double s = x.s;
if( s>59.999 ) s = 59.999;
sqlite3_str_appendf(&sRes, "%06.3f", s);
break;
}
case 'H': {
sqlite3_str_appendf(&sRes, "%02d", x.h);
break;
}
case 'W': /* Fall thru */
case 'j': {
int nDay; /* Number of days since 1st day of year */
DateTime y = x;
y.validJD = 0;
y.M = 1;
y.D = 1;
computeJD(&y);
nDay = (int)((x.iJD-y.iJD+43200000)/86400000);
if( zFmt[i]=='W' ){
int wd; /* 0=Monday, 1=Tuesday, ... 6=Sunday */
wd = (int)(((x.iJD+43200000)/86400000)%7);
sqlite3_str_appendf(&sRes,"%02d",(nDay+7-wd)/7);
}else{
sqlite3_str_appendf(&sRes,"%03d",nDay+1);
}
break;
}
case 'J': {
sqlite3_str_appendf(&sRes,"%.16g",x.iJD/86400000.0);
break;
}
case 'm': {
sqlite3_str_appendf(&sRes,"%02d",x.M);
break;
}
case 'M': {
sqlite3_str_appendf(&sRes,"%02d",x.m);
break;
}
case 's': {
i64 iS = (i64)(x.iJD/1000 - 21086676*(i64)10000);
sqlite3_str_appendf(&sRes,"%lld",iS);
break;
}
case 'S': {
sqlite3_str_appendf(&sRes,"%02d",(int)x.s);
break;
}
case 'w': {
sqlite3_str_appendchar(&sRes, 1,
(char)(((x.iJD+129600000)/86400000) % 7) + '0');
break;
}
case 'Y': {
sqlite3_str_appendf(&sRes,"%04d",x.Y);
break;
}
case '%': {
sqlite3_str_appendchar(&sRes, 1, '%');
break;
}
default: {
sqlite3_str_reset(&sRes);
return;
}
}
}
if( j<i ) sqlite3_str_append(&sRes, zFmt+j, (int)(i-j));
sqlite3ResultStrAccum(context, &sRes);
}
/*
** current_time()
**
** This function returns the same value as time('now').
*/
static void ctimeFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
UNUSED_PARAMETER2(NotUsed, NotUsed2);
timeFunc(context, 0, 0);
}
/*
** current_date()
**
** This function returns the same value as date('now').
*/
static void cdateFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
UNUSED_PARAMETER2(NotUsed, NotUsed2);
dateFunc(context, 0, 0);
}
/*
** current_timestamp()
**
** This function returns the same value as datetime('now').
*/
static void ctimestampFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
UNUSED_PARAMETER2(NotUsed, NotUsed2);
datetimeFunc(context, 0, 0);
}
#endif /* !defined(SQLITE_OMIT_DATETIME_FUNCS) */
#ifdef SQLITE_OMIT_DATETIME_FUNCS
/*
** If the library is compiled to omit the full-scale date and time
** handling (to get a smaller binary), the following minimal version
** of the functions current_time(), current_date() and current_timestamp()
** are included instead. This is to support column declarations that
** include "DEFAULT CURRENT_TIME" etc.
**
** This function uses the C-library functions time(), gmtime()
** and strftime(). The format string to pass to strftime() is supplied
** as the user-data for the function.
*/
static void currentTimeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
time_t t;
char *zFormat = (char *)sqlite3_user_data(context);
sqlite3_int64 iT;
struct tm *pTm;
struct tm sNow;
char zBuf[20];
UNUSED_PARAMETER(argc);
UNUSED_PARAMETER(argv);
iT = sqlite3StmtCurrentTime(context);
if( iT<=0 ) return;
t = iT/1000 - 10000*(sqlite3_int64)21086676;
#if HAVE_GMTIME_R
pTm = gmtime_r(&t, &sNow);
#else
sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN));
pTm = gmtime(&t);
if( pTm ) memcpy(&sNow, pTm, sizeof(sNow));
sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN));
#endif
if( pTm ){
strftime(zBuf, 20, zFormat, &sNow);
sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
}
}
#endif
/*
** This function registered all of the above C functions as SQL
** functions. This should be the only routine in this file with
** external linkage.
*/
void sqlite3RegisterDateTimeFunctions(void){
static FuncDef aDateTimeFuncs[] = {
#ifndef SQLITE_OMIT_DATETIME_FUNCS
PURE_DATE(julianday, -1, 0, 0, juliandayFunc ),
PURE_DATE(unixepoch, -1, 0, 0, unixepochFunc ),
PURE_DATE(date, -1, 0, 0, dateFunc ),
PURE_DATE(time, -1, 0, 0, timeFunc ),
PURE_DATE(datetime, -1, 0, 0, datetimeFunc ),
PURE_DATE(strftime, -1, 0, 0, strftimeFunc ),
DFUNCTION(current_time, 0, 0, 0, ctimeFunc ),
DFUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),
DFUNCTION(current_date, 0, 0, 0, cdateFunc ),
#else
STR_FUNCTION(current_time, 0, "%H:%M:%S", 0, currentTimeFunc),
STR_FUNCTION(current_date, 0, "%Y-%m-%d", 0, currentTimeFunc),
STR_FUNCTION(current_timestamp, 0, "%Y-%m-%d %H:%M:%S", 0, currentTimeFunc),
#endif
};
sqlite3InsertBuiltinFuncs(aDateTimeFuncs, ArraySize(aDateTimeFuncs));
}
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