diff options
author | Hans-Christoph Steiner <hans@eds.org> | 2012-03-30 20:42:12 -0400 |
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committer | Hans-Christoph Steiner <hans@eds.org> | 2012-03-30 20:42:12 -0400 |
commit | 7bb481fda9ecb134804b49c2ce77ca28f7eea583 (patch) | |
tree | 31b520b9914d3e2453968abe375f2c102772c3dc /src/date.c |
Imported Upstream version 2.0.3
Diffstat (limited to 'src/date.c')
-rw-r--r-- | src/date.c | 1128 |
1 files changed, 1128 insertions, 0 deletions
diff --git a/src/date.c b/src/date.c new file mode 100644 index 0000000..758dd7c --- /dev/null +++ b/src/date.c @@ -0,0 +1,1128 @@ +/* +** 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 implemention 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 +** ISBM 0-943396-61-1 +** Willmann-Bell, Inc +** Richmond, Virginia (USA) +*/ +#include "sqliteInt.h" +#include <stdlib.h> +#include <assert.h> +#include <time.h> + +#ifndef SQLITE_OMIT_DATETIME_FUNCS + + +/* +** 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 validYMD; /* True (1) if Y,M,D are valid */ + char validHMS; /* True (1) if h,m,s are valid */ + char validJD; /* True (1) if iJD is valid */ + char validTZ; /* True (1) if tz is valid */ +}; + + +/* +** Convert zDate into one or more integers. Additional arguments +** come in groups of 5 as follows: +** +** N number of digits in the integer +** min minimum allowed value of the integer +** max maximum allowed value of the integer +** nextC first character after the integer +** pVal where to write the integers value. +** +** Conversions continue until one with nextC==0 is encountered. +** The function returns the number of successful conversions. +*/ +static int getDigits(const char *zDate, ...){ + va_list ap; + int val; + int N; + int min; + int max; + int nextC; + int *pVal; + int cnt = 0; + va_start(ap, zDate); + do{ + N = va_arg(ap, int); + min = va_arg(ap, int); + max = va_arg(ap, int); + nextC = va_arg(ap, int); + pVal = va_arg(ap, int*); + val = 0; + while( N-- ){ + if( !sqlite3Isdigit(*zDate) ){ + goto end_getDigits; + } + val = val*10 + *zDate - '0'; + zDate++; + } + if( val<min || val>max || (nextC!=0 && nextC!=*zDate) ){ + goto end_getDigits; + } + *pVal = val; + zDate++; + cnt++; + }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, 2, 0, 14, ':', &nHr, 2, 0, 59, 0, &nMn)!=2 ){ + return 1; + } + zDate += 5; + p->tz = sgn*(nMn + nHr*60); +zulu_time: + while( sqlite3Isspace(*zDate) ){ zDate++; } + 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, 2, 0, 24, ':', &h, 2, 0, 59, 0, &m)!=2 ){ + return 1; + } + zDate += 5; + if( *zDate==':' ){ + zDate++; + if( getDigits(zDate, 2, 0, 59, 0, &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->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; +} + +/* +** 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( 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); + 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,4,0,9999,'-',&Y,2,1,12,'-',&M,2,1,31,0,&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){ + sqlite3 *db = sqlite3_context_db_handle(context); + if( sqlite3OsCurrentTimeInt64(db->pVfs, &p->iJD)==SQLITE_OK ){ + p->validJD = 1; + return 0; + }else{ + return 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){ + return setDateTimeToCurrent(context, p); + }else if( sqlite3AtoF(zDate, &r, sqlite3Strlen30(zDate), SQLITE_UTF8) ){ + p->iJD = (sqlite3_int64)(r*86400000.0 + 0.5); + p->validJD = 1; + return 0; + } + return 1; +} + +/* +** 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{ + 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)/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->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; +} + +/* +** 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 !defined(HAVE_LOCALTIME_R) && !defined(HAVE_LOCALTIME_S) && \ + defined(_MSC_VER) && defined(_CRT_INSECURE_DEPRECATE) +#define HAVE_LOCALTIME_S 1 +#endif + +#ifndef SQLITE_OMIT_LOCALTIME +/* +** 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 true then this +** routine will always fail. +*/ +static int osLocaltime(time_t *t, struct tm *pTm){ + int rc; +#if (!defined(HAVE_LOCALTIME_R) || !HAVE_LOCALTIME_R) \ + && (!defined(HAVE_LOCALTIME_S) || !HAVE_LOCALTIME_S) + struct tm *pX; +#if SQLITE_THREADSAFE>0 + sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); +#endif + sqlite3_mutex_enter(mutex); + pX = localtime(t); +#ifndef SQLITE_OMIT_BUILTIN_TEST + if( sqlite3GlobalConfig.bLocaltimeFault ) pX = 0; +#endif + if( pX ) *pTm = *pX; + sqlite3_mutex_leave(mutex); + rc = pX==0; +#else +#ifndef SQLITE_OMIT_BUILTIN_TEST + if( sqlite3GlobalConfig.bLocaltimeFault ) return 1; +#endif +#if defined(HAVE_LOCALTIME_R) && 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 +/* +** Compute the difference (in milliseconds) between localtime and UTC +** (a.k.a. GMT) for the time value p where p is in UTC. If no error occurs, +** return this value and set *pRc to SQLITE_OK. +** +** Or, if an error does occur, set *pRc to SQLITE_ERROR. The returned value +** is undefined in this case. +*/ +static sqlite3_int64 localtimeOffset( + DateTime *p, /* Date at which to calculate offset */ + sqlite3_context *pCtx, /* Write error here if one occurs */ + int *pRc /* OUT: Error code. SQLITE_OK or ERROR */ +){ + DateTime x, y; + time_t t; + struct tm sLocal; + + /* Initialize the contents of sLocal to avoid a compiler warning. */ + memset(&sLocal, 0, sizeof(sLocal)); + + x = *p; + computeYMD_HMS(&x); + if( x.Y<1971 || x.Y>=2038 ){ + x.Y = 2000; + x.M = 1; + x.D = 1; + x.h = 0; + x.m = 0; + x.s = 0.0; + } else { + int s = (int)(x.s + 0.5); + x.s = s; + } + x.tz = 0; + x.validJD = 0; + computeJD(&x); + t = (time_t)(x.iJD/1000 - 21086676*(i64)10000); + if( osLocaltime(&t, &sLocal) ){ + sqlite3_result_error(pCtx, "local time unavailable", -1); + *pRc = SQLITE_ERROR; + return 0; + } + y.Y = sLocal.tm_year + 1900; + y.M = sLocal.tm_mon + 1; + y.D = sLocal.tm_mday; + y.h = sLocal.tm_hour; + y.m = sLocal.tm_min; + y.s = sLocal.tm_sec; + y.validYMD = 1; + y.validHMS = 1; + y.validJD = 0; + y.validTZ = 0; + computeJD(&y); + *pRc = SQLITE_OK; + return y.iJD - x.iJD; +} +#endif /* SQLITE_OMIT_LOCALTIME */ + +/* +** 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, const char *zMod, DateTime *p){ + int rc = 1; + int n; + double r; + char *z, zBuf[30]; + z = zBuf; + for(n=0; n<ArraySize(zBuf)-1 && zMod[n]; n++){ + z[n] = (char)sqlite3UpperToLower[(u8)zMod[n]]; + } + z[n] = 0; + switch( z[0] ){ +#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( strcmp(z, "localtime")==0 ){ + computeJD(p); + p->iJD += localtimeOffset(p, pCtx, &rc); + clearYMD_HMS_TZ(p); + } + break; + } +#endif + case 'u': { + /* + ** unixepoch + ** + ** Treat the current value of p->iJD as the number of + ** seconds since 1970. Convert to a real julian day number. + */ + if( strcmp(z, "unixepoch")==0 && p->validJD ){ + p->iJD = (p->iJD + 43200)/86400 + 21086676*(i64)10000000; + clearYMD_HMS_TZ(p); + rc = 0; + } +#ifndef SQLITE_OMIT_LOCALTIME + else if( strcmp(z, "utc")==0 ){ + sqlite3_int64 c1; + computeJD(p); + c1 = localtimeOffset(p, pCtx, &rc); + if( rc==SQLITE_OK ){ + p->iJD -= c1; + clearYMD_HMS_TZ(p); + p->iJD += c1 - localtimeOffset(p, pCtx, &rc); + } + } +#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( strncmp(z, "weekday ", 8)==0 + && sqlite3AtoF(&z[8], &r, sqlite3Strlen30(&z[8]), SQLITE_UTF8) + && (n=(int)r)==r && n>=0 && r<7 ){ + 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( strncmp(z, "start of ", 9)!=0 ) break; + z += 9; + computeYMD(p); + p->validHMS = 1; + p->h = p->m = 0; + p->s = 0.0; + p->validTZ = 0; + p->validJD = 0; + if( strcmp(z,"month")==0 ){ + p->D = 1; + rc = 0; + }else if( strcmp(z,"year")==0 ){ + computeYMD(p); + p->M = 1; + p->D = 1; + rc = 0; + }else if( strcmp(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; + for(n=1; z[n] && z[n]!=':' && !sqlite3Isspace(z[n]); n++){} + if( !sqlite3AtoF(z, &r, n, SQLITE_UTF8) ){ + 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; + } + z += n; + while( sqlite3Isspace(*z) ) z++; + n = sqlite3Strlen30(z); + if( n>10 || n<3 ) break; + if( z[n-1]=='s' ){ z[n-1] = 0; n--; } + computeJD(p); + rc = 0; + rRounder = r<0 ? -0.5 : +0.5; + if( n==3 && strcmp(z,"day")==0 ){ + p->iJD += (sqlite3_int64)(r*86400000.0 + rRounder); + }else if( n==4 && strcmp(z,"hour")==0 ){ + p->iJD += (sqlite3_int64)(r*(86400000.0/24.0) + rRounder); + }else if( n==6 && strcmp(z,"minute")==0 ){ + p->iJD += (sqlite3_int64)(r*(86400000.0/(24.0*60.0)) + rRounder); + }else if( n==6 && strcmp(z,"second")==0 ){ + p->iJD += (sqlite3_int64)(r*(86400000.0/(24.0*60.0*60.0)) + rRounder); + }else if( n==5 && strcmp(z,"month")==0 ){ + int x, y; + 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; + computeJD(p); + y = (int)r; + if( y!=r ){ + p->iJD += (sqlite3_int64)((r - y)*30.0*86400000.0 + rRounder); + } + }else if( n==4 && strcmp(z,"year")==0 ){ + int y = (int)r; + computeYMD_HMS(p); + p->Y += y; + p->validJD = 0; + computeJD(p); + if( y!=r ){ + p->iJD += (sqlite3_int64)((r - y)*365.0*86400000.0 + rRounder); + } + }else{ + rc = 1; + } + 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; + const unsigned char *z; + int eType; + memset(p, 0, sizeof(*p)); + if( argc==0 ){ + return setDateTimeToCurrent(context, p); + } + if( (eType = sqlite3_value_type(argv[0]))==SQLITE_FLOAT + || eType==SQLITE_INTEGER ){ + p->iJD = (sqlite3_int64)(sqlite3_value_double(argv[0])*86400000.0 + 0.5); + p->validJD = 1; + }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]); + if( z==0 || parseModifier(context, (char*)z, p) ) 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); + } +} + +/* +** 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 ){ + char zBuf[100]; + computeYMD_HMS(&x); + sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d %02d:%02d:%02d", + x.Y, x.M, x.D, x.h, x.m, (int)(x.s)); + sqlite3_result_text(context, zBuf, -1, 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 ){ + char zBuf[100]; + computeHMS(&x); + sqlite3_snprintf(sizeof(zBuf), zBuf, "%02d:%02d:%02d", x.h, x.m, (int)x.s); + sqlite3_result_text(context, zBuf, -1, 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 ){ + char zBuf[100]; + computeYMD(&x); + sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d", x.Y, x.M, x.D); + sqlite3_result_text(context, zBuf, -1, 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; + u64 n; + size_t i,j; + char *z; + sqlite3 *db; + const char *zFmt = (const char*)sqlite3_value_text(argv[0]); + char zBuf[100]; + if( zFmt==0 || isDate(context, argc-1, argv+1, &x) ) return; + db = sqlite3_context_db_handle(context); + for(i=0, n=1; zFmt[i]; i++, n++){ + if( zFmt[i]=='%' ){ + switch( zFmt[i+1] ){ + case 'd': + case 'H': + case 'm': + case 'M': + case 'S': + case 'W': + n++; + /* fall thru */ + case 'w': + case '%': + break; + case 'f': + n += 8; + break; + case 'j': + n += 3; + break; + case 'Y': + n += 8; + break; + case 's': + case 'J': + n += 50; + break; + default: + return; /* ERROR. return a NULL */ + } + i++; + } + } + testcase( n==sizeof(zBuf)-1 ); + testcase( n==sizeof(zBuf) ); + testcase( n==(u64)db->aLimit[SQLITE_LIMIT_LENGTH]+1 ); + testcase( n==(u64)db->aLimit[SQLITE_LIMIT_LENGTH] ); + if( n<sizeof(zBuf) ){ + z = zBuf; + }else if( n>(u64)db->aLimit[SQLITE_LIMIT_LENGTH] ){ + sqlite3_result_error_toobig(context); + return; + }else{ + z = sqlite3DbMallocRaw(db, (int)n); + if( z==0 ){ + sqlite3_result_error_nomem(context); + return; + } + } + computeJD(&x); + computeYMD_HMS(&x); + for(i=j=0; zFmt[i]; i++){ + if( zFmt[i]!='%' ){ + z[j++] = zFmt[i]; + }else{ + i++; + switch( zFmt[i] ){ + case 'd': sqlite3_snprintf(3, &z[j],"%02d",x.D); j+=2; break; + case 'f': { + double s = x.s; + if( s>59.999 ) s = 59.999; + sqlite3_snprintf(7, &z[j],"%06.3f", s); + j += sqlite3Strlen30(&z[j]); + break; + } + case 'H': sqlite3_snprintf(3, &z[j],"%02d",x.h); j+=2; 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_snprintf(3, &z[j],"%02d",(nDay+7-wd)/7); + j += 2; + }else{ + sqlite3_snprintf(4, &z[j],"%03d",nDay+1); + j += 3; + } + break; + } + case 'J': { + sqlite3_snprintf(20, &z[j],"%.16g",x.iJD/86400000.0); + j+=sqlite3Strlen30(&z[j]); + break; + } + case 'm': sqlite3_snprintf(3, &z[j],"%02d",x.M); j+=2; break; + case 'M': sqlite3_snprintf(3, &z[j],"%02d",x.m); j+=2; break; + case 's': { + sqlite3_snprintf(30,&z[j],"%lld", + (i64)(x.iJD/1000 - 21086676*(i64)10000)); + j += sqlite3Strlen30(&z[j]); + break; + } + case 'S': sqlite3_snprintf(3,&z[j],"%02d",(int)x.s); j+=2; break; + case 'w': { + z[j++] = (char)(((x.iJD+129600000)/86400000) % 7) + '0'; + break; + } + case 'Y': { + sqlite3_snprintf(5,&z[j],"%04d",x.Y); j+=sqlite3Strlen30(&z[j]); + break; + } + default: z[j++] = '%'; break; + } + } + } + z[j] = 0; + sqlite3_result_text(context, z, -1, + z==zBuf ? SQLITE_TRANSIENT : SQLITE_DYNAMIC); +} + +/* +** 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 *db; + sqlite3_int64 iT; + struct tm *pTm; + struct tm sNow; + char zBuf[20]; + + UNUSED_PARAMETER(argc); + UNUSED_PARAMETER(argv); + + db = sqlite3_context_db_handle(context); + if( sqlite3OsCurrentTimeInt64(db->pVfs, &iT) ) return; + t = iT/1000 - 10000*(sqlite3_int64)21086676; +#ifdef HAVE_GMTIME_R + pTm = gmtime_r(&t, &sNow); +#else + sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)); + pTm = gmtime(&t); + if( pTm ) memcpy(&sNow, pTm, sizeof(sNow)); + sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)); +#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 SQLITE_WSD FuncDef aDateTimeFuncs[] = { +#ifndef SQLITE_OMIT_DATETIME_FUNCS + FUNCTION(julianday, -1, 0, 0, juliandayFunc ), + FUNCTION(date, -1, 0, 0, dateFunc ), + FUNCTION(time, -1, 0, 0, timeFunc ), + FUNCTION(datetime, -1, 0, 0, datetimeFunc ), + FUNCTION(strftime, -1, 0, 0, strftimeFunc ), + FUNCTION(current_time, 0, 0, 0, ctimeFunc ), + FUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc), + FUNCTION(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 + }; + int i; + FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions); + FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aDateTimeFuncs); + + for(i=0; i<ArraySize(aDateTimeFuncs); i++){ + sqlite3FuncDefInsert(pHash, &aFunc[i]); + } +} |