/* date.c - Date-parsing utility for the notmuch mail system.
*
* Copyright © 2000-2009 Jeffrey Stedfast
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see http://www.gnu.org/licenses/
*/
/* This code was originally written by from Jeffrey Stedfast
* as part of his GMime library (http://spruce.sourceforge.net/gmime/)
*
* Carl Worth <cworth@cworth.org> imported it into notmuch and removed
* some glib-isms.
*/
#include "notmuch-private.h"
#include <time.h>
#include <glib.h> /* For g_ascii_strncasecmp only. */
#ifndef FALSE
#define FALSE 0
#endif
#ifndef TRUE
#define TRUE 1
#endif
#define d(x)
#define GMIME_FOLD_PREENCODED (GMIME_FOLD_LEN / 2)
/* date parser macros */
#define NUMERIC_CHARS "1234567890"
#define WEEKDAY_CHARS "SundayMondayTuesdayWednesdayThursdayFridaySaturday"
#define MONTH_CHARS "JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember"
#define TIMEZONE_ALPHA_CHARS "UTCGMTESTEDTCSTCDTMSTPSTPDTZAMNY()"
#define TIMEZONE_NUMERIC_CHARS "-+1234567890"
#define TIME_CHARS "1234567890:"
#define DATE_TOKEN_NON_NUMERIC (1 << 0)
#define DATE_TOKEN_NON_WEEKDAY (1 << 1)
#define DATE_TOKEN_NON_MONTH (1 << 2)
#define DATE_TOKEN_NON_TIME (1 << 3)
#define DATE_TOKEN_HAS_COLON (1 << 4)
#define DATE_TOKEN_NON_TIMEZONE_ALPHA (1 << 5)
#define DATE_TOKEN_NON_TIMEZONE_NUMERIC (1 << 6)
#define DATE_TOKEN_HAS_SIGN (1 << 7)
static unsigned char gmime_datetok_table[256] = {
128,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
111,111,111,111,111,111,111,111, 79, 79,111,175,111,175,111,111,
38, 38, 38, 38, 38, 38, 38, 38, 38, 38,119,111,111,111,111,111,
111, 75,111, 79, 75, 79,105, 79,111,111,107,111,111, 73, 75,107,
79,111,111, 73, 77, 79,111,109,111, 79, 79,111,111,111,111,111,
111,105,107,107,109,105,111,107,105,105,111,111,107,107,105,105,
107,111,105,105,105,105,107,111,111,105,111,111,111,111,111,111,
111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,111,
};
/* hrm, is there a library for this stuff? */
static struct {
char *name;
int offset;
} tz_offsets [] = {
{ "UT", 0 },
{ "GMT", 0 },
{ "EST", -500 }, /* these are all US timezones. bloody yanks */
{ "EDT", -400 },
{ "CST", -600 },
{ "CDT", -500 },
{ "MST", -700 },
{ "MDT", -600 },
{ "PST", -800 },
{ "PDT", -700 },
{ "Z", 0 },
{ "A", -100 },
{ "M", -1200 },
{ "N", 100 },
{ "Y", 1200 },
};
static char *tm_months[] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
static char *tm_days[] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
/* This is where it gets ugly... */
typedef struct _date_token {
struct _date_token *next;
unsigned char mask;
const char *start;
size_t len;
} date_token;
#define date_token_free(tok) free (tok)
#define date_token_new() malloc (sizeof (date_token))
static date_token *
datetok (const char *date)
{
date_token *tokens = NULL, *token, *tail = (date_token *) &tokens;
const char *start, *end;
unsigned char mask;
start = date;
while (*start) {
/* kill leading whitespace */
while (*start == ' ' || *start == '\t')
start++;
if (*start == '\0')
break;
mask = gmime_datetok_table[(unsigned char) *start];
/* find the end of this token */
end = start + 1;
while (*end && !strchr ("-/,\t\r\n ", *end))
mask |= gmime_datetok_table[(unsigned char) *end++];
if (end != start) {
token = date_token_new ();
token->next = NULL;
token->start = start;
token->len = end - start;
token->mask = mask;
tail->next = token;
tail = token;
}
if (*end)
start = end + 1;
else
break;
}
return tokens;
}
static int
decode_int (const char *in, size_t inlen)
{
register const char *inptr;
int sign = 1, val = 0;
const char *inend;
inptr = in;
inend = in + inlen;
if (*inptr == '-') {
sign = -1;
inptr++;
} else if (*inptr == '+')
inptr++;
for ( ; inptr < inend; inptr++) {
if (!(*inptr >= '0' && *inptr <= '9'))
return -1;
else
val = (val * 10) + (*inptr - '0');
}
val *= sign;
return val;
}
#if 0
static int
get_days_in_month (int month, int year)
{
switch (month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
return 31;
case 4:
case 6:
case 9:
case 11:
return 30;
case 2:
if (g_date_is_leap_year (year))
return 29;
else
return 28;
default:
return 0;
}
}
#endif
static int
get_wday (const char *in, size_t inlen)
{
int wday;
if (in == NULL)
return -1;
if (inlen < 3)
return -1;
for (wday = 0; wday < 7; wday++) {
if (!g_ascii_strncasecmp (in, tm_days[wday], 3))
return wday;
}
return -1; /* unknown week day */
}
static int
get_mday (const char *in, size_t inlen)
{
int mday;
if (in == NULL)
return -1;
mday = decode_int (in, inlen);
if (mday < 0 || mday > 31)
mday = -1;
return mday;
}
static int
get_month (const char *in, size_t inlen)
{
int i;
if (in == NULL)
return -1;
if (inlen < 3)
return -1;
for (i = 0; i < 12; i++) {
if (!g_ascii_strncasecmp (in, tm_months[i], 3))
return i;
}
return -1; /* unknown month */
}
static int
get_year (const char *in, size_t inlen)
{
int year;
if (in == NULL)
return -1;
if ((year = decode_int (in, inlen)) == -1)
return -1;
if (year < 100)
year += (year < 70) ? 2000 : 1900;
if (year < 1969)
return -1;
return year;
}
static int
get_time (const char *in, size_t inlen, int *hour, int *min, int *sec)
{
register const char *inptr;
int *val, colons = 0;
const char *inend;
*hour = *min = *sec = 0;
inend = in + inlen;
val = hour;
for (inptr = in; inptr < inend; inptr++) {
if (*inptr == ':') {
colons++;
switch (colons) {
case 1:
val = min;
break;
case 2:
val = sec;
break;
default:
return FALSE;
}
} else if (!(*inptr >= '0' && *inptr <= '9'))
return FALSE;
else
*val = (*val * 10) + (*inptr - '0');
}
return TRUE;
}
static int
get_tzone (date_token **token)
{
const char *inptr, *inend;
size_t inlen;
int i, t;
for (i = 0; *token && i < 2; *token = (*token)->next, i++) {
inptr = (*token)->start;
inlen = (*token)->len;
inend = inptr + inlen;
if (*inptr == '+' || *inptr == '-') {
return decode_int (inptr, inlen);
} else {
if (*inptr == '(') {
inptr++;
if (*(inend - 1) == ')')
inlen -= 2;
else
inlen--;
}
for (t = 0; t < 15; t++) {
size_t len = strlen (tz_offsets[t].name);
if (len != inlen)
continue;
if (!strncmp (inptr, tz_offsets[t].name, len))
return tz_offsets[t].offset;
}
}
}
return -1;
}
#define HAVE_TIMEZONE
static time_t
mktime_utc (struct tm *tm)
{
time_t tt;
long tz;
tm->tm_isdst = -1;
tt = mktime (tm);
#if defined (G_OS_WIN32)
_get_timezone (&tz);
if (tm->tm_isdst > 0) {
int dst;
_get_dstbias (&dst);
tz += dst;
}
#elif defined (HAVE_TM_GMTOFF)
tz = -tm->tm_gmtoff;
#elif defined (HAVE_TIMEZONE)
if (tm->tm_isdst > 0) {
#if defined (HAVE_ALTZONE)
tz = altzone;
#else /* !defined (HAVE_ALTZONE) */
tz = (timezone - 3600);
#endif
} else {
tz = timezone;
}
#elif defined (HAVE__TIMEZONE)
tz = _timezone;
#else
#error Neither HAVE_TIMEZONE nor HAVE_TM_GMTOFF defined. Rerun autoheader, autoconf, etc.
#endif
return tt - tz;
}
static time_t
parse_rfc822_date (date_token *tokens, int *tzone)
{
int hour, min, sec, offset, n;
date_token *token;
struct tm tm;
time_t t;
if (tokens == NULL)
return 0;
token = tokens;
memset ((void *) &tm, 0, sizeof (struct tm));
if ((n = get_wday (token->start, token->len)) != -1) {
/* not all dates may have this... */
tm.tm_wday = n;
token = token->next;
}
/* get the mday */
if (!token || (n = get_mday (token->start, token->len)) == -1)
return (time_t) 0;
tm.tm_mday = n;
token = token->next;
/* get the month */
if (!token || (n = get_month (token->start, token->len)) == -1)
return (time_t) 0;
tm.tm_mon = n;
token = token->next;
/* get the year */
if (!token || (n = get_year (token->start, token->len)) == -1)
return (time_t) 0;
tm.tm_year = n - 1900;
token = token->next;
/* get the hour/min/sec */
if (!token || !get_time (token->start, token->len, &hour, &min, &sec))
return (time_t) 0;
tm.tm_hour = hour;
tm.tm_min = min;
tm.tm_sec = sec;
token = token->next;
/* get the timezone */
if (!token || (n = get_tzone (&token)) == -1) {
/* I guess we assume tz is GMT? */
offset = 0;
} else {
offset = n;
}
t = mktime_utc (&tm);
/* t is now GMT of the time we want, but not offset by the timezone ... */
/* this should convert the time to the GMT equiv time */
t -= ((offset / 100) * 60 * 60) + (offset % 100) * 60;
if (tzone)
*tzone = offset;
return t;
}
#define date_token_mask(t) (((date_token *) t)->mask)
#define is_numeric(t) ((date_token_mask (t) & DATE_TOKEN_NON_NUMERIC) == 0)
#define is_weekday(t) ((date_token_mask (t) & DATE_TOKEN_NON_WEEKDAY) == 0)
#define is_month(t) ((date_token_mask (t) & DATE_TOKEN_NON_MONTH) == 0)
#define is_time(t) (((date_token_mask (t) & DATE_TOKEN_NON_TIME) == 0) && (date_token_mask (t) & DATE_TOKEN_HAS_COLON))
#define is_tzone_alpha(t) ((date_token_mask (t) & DATE_TOKEN_NON_TIMEZONE_ALPHA) == 0)
#define is_tzone_numeric(t) (((date_token_mask (t) & DATE_TOKEN_NON_TIMEZONE_NUMERIC) == 0) && (date_token_mask (t) & DATE_TOKEN_HAS_SIGN))
#define is_tzone(t) (is_tzone_alpha (t) || is_tzone_numeric (t))
static time_t
parse_broken_date (date_token *tokens, int *tzone)
{
int got_wday, got_month, got_tzone;
int hour, min, sec, offset, n;
date_token *token;
struct tm tm;
time_t t;
memset ((void *) &tm, 0, sizeof (struct tm));
got_wday = got_month = got_tzone = FALSE;
offset = 0;
token = tokens;
while (token) {
if (is_weekday (token) && !got_wday) {
if ((n = get_wday (token->start, token->len)) != -1) {
d(printf ("weekday; "));
got_wday = TRUE;
tm.tm_wday = n;
goto next;
}
}
if (is_month (token) && !got_month) {
if ((n = get_month (token->start, token->len)) != -1) {
d(printf ("month; "));
got_month = TRUE;
tm.tm_mon = n;
goto next;
}
}
if (is_time (token) && !tm.tm_hour && !tm.tm_min && !tm.tm_sec) {
if (get_time (token->start, token->len, &hour, &min, &sec)) {
d(printf ("time; "));
tm.tm_hour = hour;
tm.tm_min = min;
tm.tm_sec = sec;
goto next;
}
}
if (is_tzone (token) && !got_tzone) {
date_token *t = token;
if ((n = get_tzone (&t)) != -1) {
d(printf ("tzone; "));
got_tzone = TRUE;
offset = n;
goto next;
}
}
if (is_numeric (token)) {
if (token->len == 4 && !tm.tm_year) {
if ((n = get_year (token->start, token->len)) != -1) {
d(printf ("year; "));
tm.tm_year = n - 1900;
goto next;
}
} else {
/* Note: assumes MM-DD-YY ordering if '0 < MM < 12' holds true */
if (!got_month && token->next && is_numeric (token->next)) {
if ((n = decode_int (token->start, token->len)) > 12) {
goto mday;
} else if (n > 0) {
d(printf ("mon; "));
got_month = TRUE;
tm.tm_mon = n - 1;
}
goto next;
} else if (!tm.tm_mday && (n = get_mday (token->start, token->len)) != -1) {
mday:
d(printf ("mday; "));
tm.tm_mday = n;
goto next;
} else if (!tm.tm_year) {
if ((n = get_year (token->start, token->len)) != -1) {
d(printf ("2-digit year; "));
tm.tm_year = n - 1900;
}
goto next;
}
}
}
d(printf ("???; "));
next:
token = token->next;
}
d(printf ("\n"));
t = mktime_utc (&tm);
/* t is now GMT of the time we want, but not offset by the timezone ... */
/* this should convert the time to the GMT equiv time */
t -= ((offset / 100) * 60 * 60) + (offset % 100) * 60;
if (tzone)
*tzone = offset;
return t;
}
#if 0
static void
gmime_datetok_table_init (void)
{
int i;
memset (gmime_datetok_table, 0, sizeof (gmime_datetok_table));
for (i = 0; i < 256; i++) {
if (!strchr (NUMERIC_CHARS, i))
gmime_datetok_table[i] |= DATE_TOKEN_NON_NUMERIC;
if (!strchr (WEEKDAY_CHARS, i))
gmime_datetok_table[i] |= DATE_TOKEN_NON_WEEKDAY;
if (!strchr (MONTH_CHARS, i))
gmime_datetok_table[i] |= DATE_TOKEN_NON_MONTH;
if (!strchr (TIME_CHARS, i))
gmime_datetok_table[i] |= DATE_TOKEN_NON_TIME;
if (!strchr (TIMEZONE_ALPHA_CHARS, i))
gmime_datetok_table[i] |= DATE_TOKEN_NON_TIMEZONE_ALPHA;
if (!strchr (TIMEZONE_NUMERIC_CHARS, i))
gmime_datetok_table[i] |= DATE_TOKEN_NON_TIMEZONE_NUMERIC;
if (((char) i) == ':')
gmime_datetok_table[i] |= DATE_TOKEN_HAS_COLON;
if (strchr ("+-", i))
gmime_datetok_table[i] |= DATE_TOKEN_HAS_SIGN;
}
printf ("static unsigned char gmime_datetok_table[256] = {");
for (i = 0; i < 256; i++) {
if (i % 16 == 0)
printf ("\n\t");
printf ("%3d,", gmime_datetok_table[i]);
}
printf ("\n};\n");
}
#endif
time_t
notmuch_parse_date (const char *str, int *tz_offset)
{
date_token *token, *tokens;
time_t date;
if (str == NULL)
return 0;
if (!(tokens = datetok (str))) {
if (tz_offset)
*tz_offset = 0;
return 0;
}
if (!(date = parse_rfc822_date (tokens, tz_offset)))
date = parse_broken_date (tokens, tz_offset);
/* cleanup */
while (tokens) {
token = tokens;
tokens = tokens->next;
date_token_free (token);
}
return date;
}
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