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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