Oh, I now realize the *next* patch actually does change __tz.cc. And also the Makefile for the tests that I asked about the previous patch. So sorry about the spam.
-- Nadav Har'El [email protected] On Wed, Aug 26, 2020 at 11:16 AM Nadav Har'El <[email protected]> wrote: > Can you please explain the motivation of this? > I thought maybe you are copying it instead of just enabling it in the > Makefile because you needed to change it - but the I don't see changes in > the next patches. > So what's the motivation? > > -- > Nadav Har'El > [email protected] > > > On Wed, Aug 26, 2020 at 6:54 AM Waldemar Kozaczuk <[email protected]> > wrote: > >> Signed-off-by: Waldemar Kozaczuk <[email protected]> >> --- >> libc/time/__tz.c | 389 +++++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 389 insertions(+) >> create mode 100644 libc/time/__tz.c >> >> diff --git a/libc/time/__tz.c b/libc/time/__tz.c >> new file mode 100644 >> index 00000000..a76a7b48 >> --- /dev/null >> +++ b/libc/time/__tz.c >> @@ -0,0 +1,389 @@ >> +#include "time_impl.h" >> +#include <stdint.h> >> +#include <limits.h> >> +#include <stdlib.h> >> +#include <string.h> >> +#include "libc.h" >> + >> +long __timezone = 0; >> +int __daylight = 0; >> +char *__tzname[2] = { 0, 0 }; >> + >> +weak_alias(__timezone, timezone); >> +weak_alias(__daylight, daylight); >> +weak_alias(__tzname, tzname); >> + >> +static char std_name[TZNAME_MAX+1]; >> +static char dst_name[TZNAME_MAX+1]; >> + >> +static int dst_off; >> +static int r0[5], r1[5]; >> + >> +static const unsigned char *zi, *trans, *index, *types, *abbrevs; >> +static size_t map_size; >> + >> +static char old_tz_buf[32]; >> +static char *old_tz = old_tz_buf; >> +static size_t old_tz_size = sizeof old_tz_buf; >> + >> +static int lock[2]; >> + >> +static int getint(const char **p) >> +{ >> + unsigned x; >> + for (x=0; **p-'0'<10U; (*p)++) x = **p-'0' + 10*x; >> + return x; >> +} >> + >> +static int getsigned(const char **p) >> +{ >> + if (**p == '-') { >> + ++*p; >> + return -getint(p); >> + } >> + if (**p == '+') ++*p; >> + return getint(p); >> +} >> + >> +static int getoff(const char **p) >> +{ >> + int off = 3600*getsigned(p); >> + if (**p == ':') { >> + ++*p; >> + off += 60*getint(p); >> + if (**p == ':') { >> + ++*p; >> + off += getint(p); >> + } >> + } >> + return off; >> +} >> + >> +static void getrule(const char **p, int rule[5]) >> +{ >> + int r = rule[0] = **p; >> + >> + if (r!='M') { >> + if (r=='J') ++*p; >> + else rule[0] = 0; >> + rule[1] = getint(p); >> + } else { >> + ++*p; rule[1] = getint(p); >> + ++*p; rule[2] = getint(p); >> + ++*p; rule[3] = getint(p); >> + } >> + >> + if (**p=='/') { >> + ++*p; >> + rule[4] = getoff(p); >> + } else { >> + rule[4] = 7200; >> + } >> +} >> + >> +static void getname(char *d, const char **p) >> +{ >> + int i; >> + if (**p == '<') { >> + ++*p; >> + for (i=0; **p!='>' && i<TZNAME_MAX; i++) >> + d[i] = (*p)[i]; >> + ++*p; >> + } else { >> + for (i=0; ((*p)[i]|32)-'a'<26U && i<TZNAME_MAX; i++) >> + d[i] = (*p)[i]; >> + } >> + *p += i; >> + d[i] = 0; >> +} >> + >> +#define VEC(...) ((const unsigned char[]){__VA_ARGS__}) >> + >> +static uint32_t zi_read32(const unsigned char *z) >> +{ >> + return (unsigned)z[0]<<24 | z[1]<<16 | z[2]<<8 | z[3]; >> +} >> + >> +static size_t zi_dotprod(const unsigned char *z, const unsigned char *v, >> size_t n) >> +{ >> + size_t y; >> + uint32_t x; >> + for (y=0; n; n--, z+=4, v++) { >> + x = zi_read32(z); >> + y += x * *v; >> + } >> + return y; >> +} >> + >> +int __munmap(void *, size_t); >> + >> +static void do_tzset() >> +{ >> + char buf[NAME_MAX+25], *pathname=buf+24; >> + const char *try, *s; >> + const unsigned char *map = 0; >> + size_t i; >> + static const char search[] = >> + >> "/usr/share/zoneinfo/\0/share/zoneinfo/\0/etc/zoneinfo/\0"; >> + >> + s = getenv("TZ"); >> + if (!s) s = ""; >> + >> + if (old_tz && !strcmp(s, old_tz)) return; >> + >> + if (zi) __munmap((void *)zi, map_size); >> + >> + /* Cache the old value of TZ to check if it has changed. Avoid >> + * free so as not to pull it into static programs. Growth >> + * strategy makes it so free would have minimal benefit anyway. */ >> + i = strlen(s); >> + if (i > PATH_MAX+1) s = "", i = 0; >> + if (i >= old_tz_size) { >> + old_tz_size *= 2; >> + if (i >= old_tz_size) old_tz_size = i+1; >> + if (old_tz_size > PATH_MAX+2) old_tz_size = PATH_MAX+2; >> + old_tz = malloc(old_tz_size); >> + } >> + if (old_tz) memcpy(old_tz, s, i+1); >> + >> + if (*s == ':') s++; >> + >> + /* Non-suid can use an absolute tzfile pathname or a relative >> + * pathame beginning with "."; in secure mode, only the >> + * standard path will be searched. */ >> + if (*s == '/' || *s == '.') { >> + if (!libc.secure) map = __map_file(s, &map_size); >> + } else { >> + for (i=0; s[i] && s[i]!=','; i++) { >> + if (s[i]=='/') { >> + size_t l = strlen(s); >> + if (l > NAME_MAX || strchr(s, '.')) >> + break; >> + memcpy(pathname, s, l+1); >> + pathname[l] = 0; >> + for (try=search; !map && *try; try+=l) { >> + l = strlen(try); >> + memcpy(pathname-l, try, l); >> + map = __map_file(pathname-l, >> &map_size); >> + } >> + break; >> + } >> + } >> + } >> + >> + zi = map; >> + if (map) { >> + int scale = 2; >> + if (sizeof(time_t) > 4 && map[4]=='2') { >> + size_t skip = zi_dotprod(zi, VEC(1,1,8,5,6,1), 6); >> + trans = zi+skip+44+20; >> + scale++; >> + } else { >> + trans = zi+44; >> + } >> + index = trans + (zi_read32(trans-12) << scale); >> + types = index + zi_read32(trans-12); >> + abbrevs = types + 6*zi_read32(trans-8); >> + if (zi[map_size-1] == '\n') { >> + for (s = (const char *)zi+map_size-2; *s!='\n'; >> s--); >> + s++; >> + } else { >> + s = 0; >> + } >> + } >> + >> + if (!s) s = "GMT0"; >> + getname(std_name, &s); >> + __tzname[0] = std_name; >> + __timezone = getoff(&s); >> + getname(dst_name, &s); >> + __tzname[1] = dst_name; >> + if (dst_name[0]) { >> + __daylight = 1; >> + if (*s == '+' || *s=='-' || *s-'0'<10U) >> + dst_off = getoff(&s); >> + else >> + dst_off = __timezone - 3600; >> + } else { >> + __daylight = 0; >> + dst_off = 0; >> + } >> + >> + if (*s == ',') s++, getrule(&s, r0); >> + if (*s == ',') s++, getrule(&s, r1); >> +} >> + >> +/* Search zoneinfo rules to find the one that applies to the given time, >> + * and determine alternate opposite-DST-status rule that may be needed. >> */ >> + >> +static size_t scan_trans(long long t, int local, size_t *alt) >> +{ >> + int scale = 3 - (trans == zi+44); >> + uint64_t x; >> + int off = 0; >> + >> + size_t a = 0, n = (index-trans)>>scale, m; >> + >> + if (!n) { >> + if (alt) *alt = 0; >> + return 0; >> + } >> + >> + /* Binary search for 'most-recent rule before t'. */ >> + while (n > 1) { >> + m = a + n/2; >> + x = zi_read32(trans + (m<<scale)); >> + if (scale == 3) x = x<<32 | zi_read32(trans + (m<<scale) >> + 4); >> + else x = (int32_t)x; >> + if (local) off = (int32_t)zi_read32(types + 6 * >> index[m-1]); >> + if (t - off < (int64_t)x) { >> + n /= 2; >> + } else { >> + a = m; >> + n -= n/2; >> + } >> + } >> + >> + /* First and last entry are special. First means to use >> lowest-index >> + * non-DST type. Last means to apply POSIX-style rule if >> available. */ >> + n = (index-trans)>>scale; >> + if (a == n-1) return -1; >> + if (a == 0) { >> + x = zi_read32(trans + (a<<scale)); >> + if (scale == 3) x = x<<32 | zi_read32(trans + (a<<scale) >> + 4); >> + else x = (int32_t)x; >> + if (local) off = (int32_t)zi_read32(types + 6 * >> index[a-1]); >> + if (t - off < (int64_t)x) { >> + for (a=0; a<(abbrevs-types)/6; a++) { >> + if (types[6*a+4] != types[4]) break; >> + } >> + if (a == (abbrevs-types)/6) a = 0; >> + if (types[6*a+4]) { >> + *alt = a; >> + return 0; >> + } else { >> + *alt = 0; >> + return a; >> + } >> + } >> + } >> + >> + /* Try to find a neighboring opposite-DST-status rule. */ >> + if (alt) { >> + if (a && types[6*index[a-1]+4] != types[6*index[a]+4]) >> + *alt = index[a-1]; >> + else if (a+1<n && types[6*index[a+1]+4] != >> types[6*index[a]+4]) >> + *alt = index[a+1]; >> + else >> + *alt = index[a]; >> + } >> + >> + return index[a]; >> +} >> + >> +static int days_in_month(int m, int is_leap) >> +{ >> + if (m==2) return 28+is_leap; >> + else return 30+((0xad5>>(m-1))&1); >> +} >> + >> +/* Convert a POSIX DST rule plus year to seconds since epoch. */ >> + >> +static long long rule_to_secs(const int *rule, int year) >> +{ >> + int is_leap; >> + long long t = __year_to_secs(year, &is_leap); >> + int x, m, n, d; >> + if (rule[0]!='M') { >> + x = rule[1]; >> + if (rule[0]=='J' && (x < 60 || !is_leap)) x--; >> + t += 86400 * x; >> + } else { >> + m = rule[1]; >> + n = rule[2]; >> + d = rule[3]; >> + t += __month_to_secs(m-1, is_leap); >> + int wday = (int)((t + 4*86400) % (7*86400)) / 86400; >> + int days = d - wday; >> + if (days < 0) days += 7; >> + if (n == 5 && days+28 >= days_in_month(m, is_leap)) n = 4; >> + t += 86400 * (days + 7*(n-1)); >> + } >> + t += rule[4]; >> + return t; >> +} >> + >> +/* Determine the time zone in effect for a given time in seconds since >> the >> + * epoch. It can be given in local or universal time. The results will >> + * indicate whether DST is in effect at the queried time, and will give >> both >> + * the GMT offset for the active zone/DST rule and the opposite DST. This >> + * enables a caller to efficiently adjust for the case where an explicit >> + * DST specification mismatches what would be in effect at the time. */ >> + >> +void __secs_to_zone(long long t, int local, int *isdst, long *offset, >> long *oppoff, const char **zonename) >> +{ >> + LOCK(lock); >> + >> + do_tzset(); >> + >> + if (zi) { >> + size_t alt, i = scan_trans(t, local, &alt); >> + if (i != -1) { >> + *isdst = types[6*i+4]; >> + *offset = -(int32_t)zi_read32(types+6*i); >> + *zonename = (const char *)abbrevs + types[6*i+5]; >> + if (oppoff) *oppoff = >> -(int32_t)zi_read32(types+6*alt); >> + UNLOCK(lock); >> + return; >> + } >> + } >> + >> + if (!__daylight) goto std; >> + >> + /* FIXME: may be broken if DST changes right at year boundary? >> + * Also, this could be more efficient.*/ >> + long long y = t / 31556952 + 70; >> + while (__year_to_secs(y, 0) > t) y--; >> + while (__year_to_secs(y+1, 0) < t) y++; >> + >> + long long t0 = rule_to_secs(r0, y); >> + long long t1 = rule_to_secs(r1, y); >> + >> + if (t0 < t1) { >> + if (!local) { >> + t0 += __timezone; >> + t1 += dst_off; >> + } >> + if (t >= t0 && t < t1) goto dst; >> + goto std; >> + } else { >> + if (!local) { >> + t1 += __timezone; >> + t0 += dst_off; >> + } >> + if (t >= t1 && t < t0) goto std; >> + goto dst; >> + } >> +std: >> + *isdst = 0; >> + *offset = __timezone; >> + if (oppoff) *oppoff = dst_off; >> + *zonename = __tzname[0]; >> + UNLOCK(lock); >> + return; >> +dst: >> + *isdst = 1; >> + *offset = dst_off; >> + if (oppoff) *oppoff = __timezone; >> + *zonename = __tzname[1]; >> + UNLOCK(lock); >> +} >> + >> +void __tzset() >> +{ >> + LOCK(lock); >> + do_tzset(); >> + UNLOCK(lock); >> +} >> + >> +weak_alias(__tzset, tzset); >> -- >> 2.26.2 >> >> -- >> You received this message because you are subscribed to the Google Groups >> "OSv Development" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/osv-dev/20200826035356.201786-3-jwkozaczuk%40gmail.com >> . >> > -- You received this message because you are subscribed to the Google Groups "OSv Development" group. 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