Source code
Revision control
Copy as Markdown
Other Tools
// Copyright 2016 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#if !defined(HAS_STRPTIME)
#if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__VXWORKS__)
#define HAS_STRPTIME 1 // Assume everyone else has strptime().
#endif
#endif
#if defined(HAS_STRPTIME) && HAS_STRPTIME
#if !defined(_XOPEN_SOURCE) && !defined(__FreeBSD__) && !defined(__OpenBSD__)
#define _XOPEN_SOURCE 500 // Exposes definitions for SUSv2 (UNIX 98).
#endif
#endif
#include "absl/base/config.h"
#include "absl/time/internal/cctz/include/cctz/time_zone.h"
// Include time.h directly since, by C++ standards, ctime doesn't have to
// declare strptime.
#include <time.h>
#include <cctype>
#include <chrono>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <ctime>
#include <limits>
#include <string>
#include <vector>
#if !HAS_STRPTIME
#include <iomanip>
#include <sstream>
#endif
#include "absl/time/internal/cctz/include/cctz/civil_time.h"
#include "time_zone_if.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace time_internal {
namespace cctz {
namespace detail {
namespace {
#if !HAS_STRPTIME
// Build a strptime() using C++11's std::get_time().
char* strptime(const char* s, const char* fmt, std::tm* tm) {
std::istringstream input(s);
input >> std::get_time(tm, fmt);
if (input.fail()) return nullptr;
return const_cast<char*>(s) +
(input.eof() ? strlen(s) : static_cast<std::size_t>(input.tellg()));
}
#endif
// Convert a cctz::weekday to a tm_wday value (0-6, Sunday = 0).
int ToTmWday(weekday wd) {
switch (wd) {
case weekday::sunday:
return 0;
case weekday::monday:
return 1;
case weekday::tuesday:
return 2;
case weekday::wednesday:
return 3;
case weekday::thursday:
return 4;
case weekday::friday:
return 5;
case weekday::saturday:
return 6;
}
return 0; /*NOTREACHED*/
}
// Convert a tm_wday value (0-6, Sunday = 0) to a cctz::weekday.
weekday FromTmWday(int tm_wday) {
switch (tm_wday) {
case 0:
return weekday::sunday;
case 1:
return weekday::monday;
case 2:
return weekday::tuesday;
case 3:
return weekday::wednesday;
case 4:
return weekday::thursday;
case 5:
return weekday::friday;
case 6:
return weekday::saturday;
}
return weekday::sunday; /*NOTREACHED*/
}
std::tm ToTM(const time_zone::absolute_lookup& al) {
std::tm tm{};
tm.tm_sec = al.cs.second();
tm.tm_min = al.cs.minute();
tm.tm_hour = al.cs.hour();
tm.tm_mday = al.cs.day();
tm.tm_mon = al.cs.month() - 1;
// Saturate tm.tm_year is cases of over/underflow.
if (al.cs.year() < std::numeric_limits<int>::min() + 1900) {
tm.tm_year = std::numeric_limits<int>::min();
} else if (al.cs.year() - 1900 > std::numeric_limits<int>::max()) {
tm.tm_year = std::numeric_limits<int>::max();
} else {
tm.tm_year = static_cast<int>(al.cs.year() - 1900);
}
tm.tm_wday = ToTmWday(get_weekday(al.cs));
tm.tm_yday = get_yearday(al.cs) - 1;
tm.tm_isdst = al.is_dst ? 1 : 0;
return tm;
}
// Returns the week of the year [0:53] given a civil day and the day on
// which weeks are defined to start.
int ToWeek(const civil_day& cd, weekday week_start) {
const civil_day d(cd.year() % 400, cd.month(), cd.day());
return static_cast<int>((d - prev_weekday(civil_year(d), week_start)) / 7);
}
const char kDigits[] = "0123456789";
// Formats a 64-bit integer in the given field width. Note that it is up
// to the caller of Format64() [and Format02d()/FormatOffset()] to ensure
// that there is sufficient space before ep to hold the conversion.
char* Format64(char* ep, int width, std::int_fast64_t v) {
bool neg = false;
if (v < 0) {
--width;
neg = true;
if (v == std::numeric_limits<std::int_fast64_t>::min()) {
// Avoid negating minimum value.
std::int_fast64_t last_digit = -(v % 10);
v /= 10;
if (last_digit < 0) {
++v;
last_digit += 10;
}
--width;
*--ep = kDigits[last_digit];
}
v = -v;
}
do {
--width;
*--ep = kDigits[v % 10];
} while (v /= 10);
while (--width >= 0) *--ep = '0'; // zero pad
if (neg) *--ep = '-';
return ep;
}
// Formats [0 .. 99] as %02d.
char* Format02d(char* ep, int v) {
*--ep = kDigits[v % 10];
*--ep = kDigits[(v / 10) % 10];
return ep;
}
// Formats a UTC offset, like +00:00.
char* FormatOffset(char* ep, int offset, const char* mode) {
// TODO: Follow the RFC3339 "Unknown Local Offset Convention" and
// generate a "negative zero" when we're formatting a zero offset
// as the result of a failed load_time_zone().
char sign = '+';
if (offset < 0) {
offset = -offset; // bounded by 24h so no overflow
sign = '-';
}
const int seconds = offset % 60;
const int minutes = (offset /= 60) % 60;
const int hours = offset /= 60;
const char sep = mode[0];
const bool ext = (sep != '\0' && mode[1] == '*');
const bool ccc = (ext && mode[2] == ':');
if (ext && (!ccc || seconds != 0)) {
ep = Format02d(ep, seconds);
*--ep = sep;
} else {
// If we're not rendering seconds, sub-minute negative offsets
// should get a positive sign (e.g., offset=-10s => "+00:00").
if (hours == 0 && minutes == 0) sign = '+';
}
if (!ccc || minutes != 0 || seconds != 0) {
ep = Format02d(ep, minutes);
if (sep != '\0') *--ep = sep;
}
ep = Format02d(ep, hours);
*--ep = sign;
return ep;
}
// Formats a std::tm using strftime(3).
void FormatTM(std::string* out, const std::string& fmt, const std::tm& tm) {
// strftime(3) returns the number of characters placed in the output
// array (which may be 0 characters). It also returns 0 to indicate
// an error, like the array wasn't large enough. To accommodate this,
// the following code grows the buffer size from 2x the format string
// length up to 32x.
for (std::size_t i = 2; i != 32; i *= 2) {
std::size_t buf_size = fmt.size() * i;
std::vector<char> buf(buf_size);
if (std::size_t len = strftime(&buf[0], buf_size, fmt.c_str(), &tm)) {
out->append(&buf[0], len);
return;
}
}
}
// Used for %E#S/%E#f specifiers and for data values in parse().
template <typename T>
const char* ParseInt(const char* dp, int width, T min, T max, T* vp) {
if (dp != nullptr) {
const T kmin = std::numeric_limits<T>::min();
bool erange = false;
bool neg = false;
T value = 0;
if (*dp == '-') {
neg = true;
if (width <= 0 || --width != 0) {
++dp;
} else {
dp = nullptr; // width was 1
}
}
if (const char* const bp = dp) {
while (const char* cp = strchr(kDigits, *dp)) {
int d = static_cast<int>(cp - kDigits);
if (d >= 10) break;
if (value < kmin / 10) {
erange = true;
break;
}
value *= 10;
if (value < kmin + d) {
erange = true;
break;
}
value -= d;
dp += 1;
if (width > 0 && --width == 0) break;
}
if (dp != bp && !erange && (neg || value != kmin)) {
if (!neg || value != 0) {
if (!neg) value = -value; // make positive
if (min <= value && value <= max) {
*vp = value;
} else {
dp = nullptr;
}
} else {
dp = nullptr;
}
} else {
dp = nullptr;
}
}
}
return dp;
}
// The number of base-10 digits that can be represented by a signed 64-bit
// integer. That is, 10^kDigits10_64 <= 2^63 - 1 < 10^(kDigits10_64 + 1).
const int kDigits10_64 = 18;
// 10^n for everything that can be represented by a signed 64-bit integer.
const std::int_fast64_t kExp10[kDigits10_64 + 1] = {
1,
10,
100,
1000,
10000,
100000,
1000000,
10000000,
100000000,
1000000000,
10000000000,
100000000000,
1000000000000,
10000000000000,
100000000000000,
1000000000000000,
10000000000000000,
100000000000000000,
1000000000000000000,
};
} // namespace
// Uses strftime(3) to format the given Time. The following extended format
// specifiers are also supported:
//
// - %Ez - RFC3339-compatible numeric UTC offset (+hh:mm or -hh:mm)
// - %E*z - Full-resolution numeric UTC offset (+hh:mm:ss or -hh:mm:ss)
// - %E#S - Seconds with # digits of fractional precision
// - %E*S - Seconds with full fractional precision (a literal '*')
// - %E4Y - Four-character years (-999 ... -001, 0000, 0001 ... 9999)
// - %ET - The RFC3339 "date-time" separator "T"
//
// The standard specifiers from RFC3339_* (%Y, %m, %d, %H, %M, and %S) are
// handled internally for performance reasons. strftime(3) is slow due to
// a POSIX requirement to respect changes to ${TZ}.
//
// The TZ/GNU %s extension is handled internally because strftime() has
// to use mktime() to generate it, and that assumes the local time zone.
//
// We also handle the %z and %Z specifiers to accommodate platforms that do
// not support the tm_gmtoff and tm_zone extensions to std::tm.
//
// Requires that zero() <= fs < seconds(1).
std::string format(const std::string& format, const time_point<seconds>& tp,
const detail::femtoseconds& fs, const time_zone& tz) {
std::string result;
result.reserve(format.size()); // A reasonable guess for the result size.
const time_zone::absolute_lookup al = tz.lookup(tp);
const std::tm tm = ToTM(al);
// Scratch buffer for internal conversions.
char buf[3 + kDigits10_64]; // enough for longest conversion
char* const ep = buf + sizeof(buf);
char* bp; // works back from ep
// Maintain three, disjoint subsequences that span format.
// [format.begin() ... pending) : already formatted into result
// [pending ... cur) : formatting pending, but no special cases
// [cur ... format.end()) : unexamined
// Initially, everything is in the unexamined part.
const char* pending = format.c_str(); // NUL terminated
const char* cur = pending;
const char* end = pending + format.length();
while (cur != end) { // while something is unexamined
// Moves cur to the next percent sign.
const char* start = cur;
while (cur != end && *cur != '%') ++cur;
// If the new pending text is all ordinary, copy it out.
if (cur != start && pending == start) {
result.append(pending, static_cast<std::size_t>(cur - pending));
pending = start = cur;
}
// Span the sequential percent signs.
const char* percent = cur;
while (cur != end && *cur == '%') ++cur;
// If the new pending text is all percents, copy out one
// percent for every matched pair, then skip those pairs.
if (cur != start && pending == start) {
std::size_t escaped = static_cast<std::size_t>(cur - pending) / 2;
result.append(pending, escaped);
pending += escaped * 2;
// Also copy out a single trailing percent.
if (pending != cur && cur == end) {
result.push_back(*pending++);
}
}
// Loop unless we have an unescaped percent.
if (cur == end || (cur - percent) % 2 == 0) continue;
// Simple specifiers that we handle ourselves.
if (strchr("YmdeUuWwHMSzZs%", *cur)) {
if (cur - 1 != pending) {
FormatTM(&result, std::string(pending, cur - 1), tm);
}
switch (*cur) {
case 'Y':
// This avoids the tm.tm_year overflow problem for %Y, however
// tm.tm_year will still be used by other specifiers like %D.
bp = Format64(ep, 0, al.cs.year());
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'm':
bp = Format02d(ep, al.cs.month());
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'd':
case 'e':
bp = Format02d(ep, al.cs.day());
if (*cur == 'e' && *bp == '0') *bp = ' '; // for Windows
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'U':
bp = Format02d(ep, ToWeek(civil_day(al.cs), weekday::sunday));
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'u':
bp = Format64(ep, 0, tm.tm_wday ? tm.tm_wday : 7);
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'W':
bp = Format02d(ep, ToWeek(civil_day(al.cs), weekday::monday));
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'w':
bp = Format64(ep, 0, tm.tm_wday);
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'H':
bp = Format02d(ep, al.cs.hour());
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'M':
bp = Format02d(ep, al.cs.minute());
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'S':
bp = Format02d(ep, al.cs.second());
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'z':
bp = FormatOffset(ep, al.offset, "");
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case 'Z':
result.append(al.abbr);
break;
case 's':
bp = Format64(ep, 0, ToUnixSeconds(tp));
result.append(bp, static_cast<std::size_t>(ep - bp));
break;
case '%':
result.push_back('%');
break;
}
pending = ++cur;
continue;
}
// More complex specifiers that we handle ourselves.
if (*cur == ':' && cur + 1 != end) {
if (*(cur + 1) == 'z') {
// Formats %:z.
if (cur - 1 != pending) {
FormatTM(&result, std::string(pending, cur - 1), tm);
}
bp = FormatOffset(ep, al.offset, ":");
result.append(bp, static_cast<std::size_t>(ep - bp));
pending = cur += 2;
continue;
}
if (*(cur + 1) == ':' && cur + 2 != end) {
if (*(cur + 2) == 'z') {
// Formats %::z.
if (cur - 1 != pending) {
FormatTM(&result, std::string(pending, cur - 1), tm);
}
bp = FormatOffset(ep, al.offset, ":*");
result.append(bp, static_cast<std::size_t>(ep - bp));
pending = cur += 3;
continue;
}
if (*(cur + 2) == ':' && cur + 3 != end) {
if (*(cur + 3) == 'z') {
// Formats %:::z.
if (cur - 1 != pending) {
FormatTM(&result, std::string(pending, cur - 1), tm);
}
bp = FormatOffset(ep, al.offset, ":*:");
result.append(bp, static_cast<std::size_t>(ep - bp));
pending = cur += 4;
continue;
}
}
}
}
// Loop if there is no E modifier.
if (*cur != 'E' || ++cur == end) continue;
// Format our extensions.
if (*cur == 'T') {
// Formats %ET.
if (cur - 2 != pending) {
FormatTM(&result, std::string(pending, cur - 2), tm);
}
result.append("T");
pending = ++cur;
} else if (*cur == 'z') {
// Formats %Ez.
if (cur - 2 != pending) {
FormatTM(&result, std::string(pending, cur - 2), tm);
}
bp = FormatOffset(ep, al.offset, ":");
result.append(bp, static_cast<std::size_t>(ep - bp));
pending = ++cur;
} else if (*cur == '*' && cur + 1 != end && *(cur + 1) == 'z') {
// Formats %E*z.
if (cur - 2 != pending) {
FormatTM(&result, std::string(pending, cur - 2), tm);
}
bp = FormatOffset(ep, al.offset, ":*");
result.append(bp, static_cast<std::size_t>(ep - bp));
pending = cur += 2;
} else if (*cur == '*' && cur + 1 != end &&
(*(cur + 1) == 'S' || *(cur + 1) == 'f')) {
// Formats %E*S or %E*F.
if (cur - 2 != pending) {
FormatTM(&result, std::string(pending, cur - 2), tm);
}
char* cp = ep;
bp = Format64(cp, 15, fs.count());
while (cp != bp && cp[-1] == '0') --cp;
switch (*(cur + 1)) {
case 'S':
if (cp != bp) *--bp = '.';
bp = Format02d(bp, al.cs.second());
break;
case 'f':
if (cp == bp) *--bp = '0';
break;
}
result.append(bp, static_cast<std::size_t>(cp - bp));
pending = cur += 2;
} else if (*cur == '4' && cur + 1 != end && *(cur + 1) == 'Y') {
// Formats %E4Y.
if (cur - 2 != pending) {
FormatTM(&result, std::string(pending, cur - 2), tm);
}
bp = Format64(ep, 4, al.cs.year());
result.append(bp, static_cast<std::size_t>(ep - bp));
pending = cur += 2;
} else if (std::isdigit(*cur)) {
// Possibly found %E#S or %E#f.
int n = 0;
if (const char* np = ParseInt(cur, 0, 0, 1024, &n)) {
if (*np == 'S' || *np == 'f') {
// Formats %E#S or %E#f.
if (cur - 2 != pending) {
FormatTM(&result, std::string(pending, cur - 2), tm);
}
bp = ep;
if (n > 0) {
if (n > kDigits10_64) n = kDigits10_64;
bp = Format64(bp, n,
(n > 15) ? fs.count() * kExp10[n - 15]
: fs.count() / kExp10[15 - n]);
if (*np == 'S') *--bp = '.';
}
if (*np == 'S') bp = Format02d(bp, al.cs.second());
result.append(bp, static_cast<std::size_t>(ep - bp));
pending = cur = ++np;
}
}
}
}
// Formats any remaining data.
if (end != pending) {
FormatTM(&result, std::string(pending, end), tm);
}
return result;
}
namespace {
const char* ParseOffset(const char* dp, const char* mode, int* offset) {
if (dp != nullptr) {
const char first = *dp++;
if (first == '+' || first == '-') {
char sep = mode[0];
int hours = 0;
int minutes = 0;
int seconds = 0;
const char* ap = ParseInt(dp, 2, 0, 23, &hours);
if (ap != nullptr && ap - dp == 2) {
dp = ap;
if (sep != '\0' && *ap == sep) ++ap;
const char* bp = ParseInt(ap, 2, 0, 59, &minutes);
if (bp != nullptr && bp - ap == 2) {
dp = bp;
if (sep != '\0' && *bp == sep) ++bp;
const char* cp = ParseInt(bp, 2, 0, 59, &seconds);
if (cp != nullptr && cp - bp == 2) dp = cp;
}
*offset = ((hours * 60 + minutes) * 60) + seconds;
if (first == '-') *offset = -*offset;
} else {
dp = nullptr;
}
} else if (first == 'Z' || first == 'z') { // Zulu
*offset = 0;
} else {
dp = nullptr;
}
}
return dp;
}
const char* ParseZone(const char* dp, std::string* zone) {
zone->clear();
if (dp != nullptr) {
while (*dp != '\0' && !std::isspace(*dp)) zone->push_back(*dp++);
if (zone->empty()) dp = nullptr;
}
return dp;
}
const char* ParseSubSeconds(const char* dp, detail::femtoseconds* subseconds) {
if (dp != nullptr) {
std::int_fast64_t v = 0;
std::int_fast64_t exp = 0;
const char* const bp = dp;
while (const char* cp = strchr(kDigits, *dp)) {
int d = static_cast<int>(cp - kDigits);
if (d >= 10) break;
if (exp < 15) {
exp += 1;
v *= 10;
v += d;
}
++dp;
}
if (dp != bp) {
v *= kExp10[15 - exp];
*subseconds = detail::femtoseconds(v);
} else {
dp = nullptr;
}
}
return dp;
}
// Parses a string into a std::tm using strptime(3).
const char* ParseTM(const char* dp, const char* fmt, std::tm* tm) {
if (dp != nullptr) {
dp = strptime(dp, fmt, tm);
}
return dp;
}
// Sets year, tm_mon and tm_mday given the year, week_num, and tm_wday,
// and the day on which weeks are defined to start. Returns false if year
// would need to move outside its bounds.
bool FromWeek(int week_num, weekday week_start, year_t* year, std::tm* tm) {
const civil_year y(*year % 400);
civil_day cd = prev_weekday(y, week_start); // week 0
cd = next_weekday(cd - 1, FromTmWday(tm->tm_wday)) + (week_num * 7);
if (const year_t shift = cd.year() - y.year()) {
if (shift > 0) {
if (*year > std::numeric_limits<year_t>::max() - shift) return false;
} else {
if (*year < std::numeric_limits<year_t>::min() - shift) return false;
}
*year += shift;
}
tm->tm_mon = cd.month() - 1;
tm->tm_mday = cd.day();
return true;
}
} // namespace
// Uses strptime(3) to parse the given input. Supports the same extended
// format specifiers as format(), although %E#S and %E*S are treated
// identically (and similarly for %E#f and %E*f). %Ez and %E*z also accept
// the same inputs. %ET accepts either 'T' or 't'.
//
// The standard specifiers from RFC3339_* (%Y, %m, %d, %H, %M, and %S) are
// handled internally so that we can normally avoid strptime() altogether
// (which is particularly helpful when the native implementation is broken).
//
// The TZ/GNU %s extension is handled internally because strptime() has to
// use localtime_r() to generate it, and that assumes the local time zone.
//
// We also handle the %z specifier to accommodate platforms that do not
// support the tm_gmtoff extension to std::tm. %Z is parsed but ignored.
bool parse(const std::string& format, const std::string& input,
const time_zone& tz, time_point<seconds>* sec,
detail::femtoseconds* fs, std::string* err) {
// The unparsed input.
const char* data = input.c_str(); // NUL terminated
// Skips leading whitespace.
while (std::isspace(*data)) ++data;
const year_t kyearmax = std::numeric_limits<year_t>::max();
const year_t kyearmin = std::numeric_limits<year_t>::min();
// Sets default values for unspecified fields.
bool saw_year = false;
year_t year = 1970;
std::tm tm{};
tm.tm_year = 1970 - 1900;
tm.tm_mon = 1 - 1; // Jan
tm.tm_mday = 1;
tm.tm_hour = 0;
tm.tm_min = 0;
tm.tm_sec = 0;
tm.tm_wday = 4; // Thu
tm.tm_yday = 0;
tm.tm_isdst = 0;
auto subseconds = detail::femtoseconds::zero();
bool saw_offset = false;
int offset = 0; // No offset from passed tz.
std::string zone = "UTC";
const char* fmt = format.c_str(); // NUL terminated
bool twelve_hour = false;
bool afternoon = false;
int week_num = -1;
weekday week_start = weekday::sunday;
bool saw_percent_s = false;
std::int_fast64_t percent_s = 0;
// Steps through format, one specifier at a time.
while (data != nullptr && *fmt != '\0') {
if (std::isspace(*fmt)) {
while (std::isspace(*data)) ++data;
while (std::isspace(*++fmt)) continue;
continue;
}
if (*fmt != '%') {
if (*data == *fmt) {
++data;
++fmt;
} else {
data = nullptr;
}
continue;
}
const char* percent = fmt;
if (*++fmt == '\0') {
data = nullptr;
continue;
}
switch (*fmt++) {
case 'Y':
// Symmetrically with FormatTime(), directly handing %Y avoids the
// tm.tm_year overflow problem. However, tm.tm_year will still be
// used by other specifiers like %D.
data = ParseInt(data, 0, kyearmin, kyearmax, &year);
if (data != nullptr) saw_year = true;
continue;
case 'm':
data = ParseInt(data, 2, 1, 12, &tm.tm_mon);
if (data != nullptr) tm.tm_mon -= 1;
week_num = -1;
continue;
case 'd':
case 'e':
data = ParseInt(data, 2, 1, 31, &tm.tm_mday);
week_num = -1;
continue;
case 'U':
data = ParseInt(data, 0, 0, 53, &week_num);
week_start = weekday::sunday;
continue;
case 'W':
data = ParseInt(data, 0, 0, 53, &week_num);
week_start = weekday::monday;
continue;
case 'u':
data = ParseInt(data, 0, 1, 7, &tm.tm_wday);
if (data != nullptr) tm.tm_wday %= 7;
continue;
case 'w':
data = ParseInt(data, 0, 0, 6, &tm.tm_wday);
continue;
case 'H':
data = ParseInt(data, 2, 0, 23, &tm.tm_hour);
twelve_hour = false;
continue;
case 'M':
data = ParseInt(data, 2, 0, 59, &tm.tm_min);
continue;
case 'S':
data = ParseInt(data, 2, 0, 60, &tm.tm_sec);
continue;
case 'I':
case 'l':
case 'r': // probably uses %I
twelve_hour = true;
break;
case 'R': // uses %H
case 'T': // uses %H
case 'c': // probably uses %H
case 'X': // probably uses %H
twelve_hour = false;
break;
case 'z':
data = ParseOffset(data, "", &offset);
if (data != nullptr) saw_offset = true;
continue;
case 'Z': // ignored; zone abbreviations are ambiguous
data = ParseZone(data, &zone);
continue;
case 's':
data =
ParseInt(data, 0, std::numeric_limits<std::int_fast64_t>::min(),
std::numeric_limits<std::int_fast64_t>::max(), &percent_s);
if (data != nullptr) saw_percent_s = true;
continue;
case ':':
if (fmt[0] == 'z' ||
(fmt[0] == ':' &&
(fmt[1] == 'z' || (fmt[1] == ':' && fmt[2] == 'z')))) {
data = ParseOffset(data, ":", &offset);
if (data != nullptr) saw_offset = true;
fmt += (fmt[0] == 'z') ? 1 : (fmt[1] == 'z') ? 2 : 3;
continue;
}
break;
case '%':
data = (*data == '%' ? data + 1 : nullptr);
continue;
case 'E':
if (fmt[0] == 'T') {
if (*data == 'T' || *data == 't') {
++data;
++fmt;
} else {
data = nullptr;
}
continue;
}
if (fmt[0] == 'z' || (fmt[0] == '*' && fmt[1] == 'z')) {
data = ParseOffset(data, ":", &offset);
if (data != nullptr) saw_offset = true;
fmt += (fmt[0] == 'z') ? 1 : 2;
continue;
}
if (fmt[0] == '*' && fmt[1] == 'S') {
data = ParseInt(data, 2, 0, 60, &tm.tm_sec);
if (data != nullptr && *data == '.') {
data = ParseSubSeconds(data + 1, &subseconds);
}
fmt += 2;
continue;
}
if (fmt[0] == '*' && fmt[1] == 'f') {
if (data != nullptr && std::isdigit(*data)) {
data = ParseSubSeconds(data, &subseconds);
}
fmt += 2;
continue;
}
if (fmt[0] == '4' && fmt[1] == 'Y') {
const char* bp = data;
data = ParseInt(data, 4, year_t{-999}, year_t{9999}, &year);
if (data != nullptr) {
if (data - bp == 4) {
saw_year = true;
} else {
data = nullptr; // stopped too soon
}
}
fmt += 2;
continue;
}
if (std::isdigit(*fmt)) {
int n = 0; // value ignored
if (const char* np = ParseInt(fmt, 0, 0, 1024, &n)) {
if (*np == 'S') {
data = ParseInt(data, 2, 0, 60, &tm.tm_sec);
if (data != nullptr && *data == '.') {
data = ParseSubSeconds(data + 1, &subseconds);
}
fmt = ++np;
continue;
}
if (*np == 'f') {
if (data != nullptr && std::isdigit(*data)) {
data = ParseSubSeconds(data, &subseconds);
}
fmt = ++np;
continue;
}
}
}
if (*fmt == 'c') twelve_hour = false; // probably uses %H
if (*fmt == 'X') twelve_hour = false; // probably uses %H
if (*fmt != '\0') ++fmt;
break;
case 'O':
if (*fmt == 'H') twelve_hour = false;
if (*fmt == 'I') twelve_hour = true;
if (*fmt != '\0') ++fmt;
break;
}
// Parses the current specifier.
const char* orig_data = data;
std::string spec(percent, static_cast<std::size_t>(fmt - percent));
data = ParseTM(data, spec.c_str(), &tm);
// If we successfully parsed %p we need to remember whether the result
// was AM or PM so that we can adjust tm_hour before time_zone::lookup().
// So reparse the input with a known AM hour, and check if it is shifted
// to a PM hour.
if (spec == "%p" && data != nullptr) {
std::string test_input = "1";
test_input.append(orig_data, static_cast<std::size_t>(data - orig_data));
const char* test_data = test_input.c_str();
std::tm tmp{};
ParseTM(test_data, "%I%p", &tmp);
afternoon = (tmp.tm_hour == 13);
}
}
// Adjust a 12-hour tm_hour value if it should be in the afternoon.
if (twelve_hour && afternoon && tm.tm_hour < 12) {
tm.tm_hour += 12;
}
if (data == nullptr) {
if (err != nullptr) *err = "Failed to parse input";
return false;
}
// Skip any remaining whitespace.
while (std::isspace(*data)) ++data;
// parse() must consume the entire input string.
if (*data != '\0') {
if (err != nullptr) *err = "Illegal trailing data in input string";
return false;
}
// If we saw %s then we ignore anything else and return that time.
if (saw_percent_s) {
*sec = FromUnixSeconds(percent_s);
*fs = detail::femtoseconds::zero();
return true;
}
// If we saw %z, %Ez, or %E*z then we want to interpret the parsed fields
// in UTC and then shift by that offset. Otherwise we want to interpret
// the fields directly in the passed time_zone.
time_zone ptz = saw_offset ? utc_time_zone() : tz;
// Allows a leap second of 60 to normalize forward to the following ":00".
if (tm.tm_sec == 60) {
tm.tm_sec -= 1;
offset -= 1;
subseconds = detail::femtoseconds::zero();
}
if (!saw_year) {
year = year_t{tm.tm_year};
if (year > kyearmax - 1900) {
// Platform-dependent, maybe unreachable.
if (err != nullptr) *err = "Out-of-range year";
return false;
}
year += 1900;
}
// Compute year, tm.tm_mon and tm.tm_mday if we parsed a week number.
if (week_num != -1) {
if (!FromWeek(week_num, week_start, &year, &tm)) {
if (err != nullptr) *err = "Out-of-range field";
return false;
}
}
const int month = tm.tm_mon + 1;
civil_second cs(year, month, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
// parse() should not allow normalization. Due to the restricted field
// ranges above (see ParseInt()), the only possibility is for days to roll
// into months. That is, parsing "Sep 31" should not produce "Oct 1".
if (cs.month() != month || cs.day() != tm.tm_mday) {
if (err != nullptr) *err = "Out-of-range field";
return false;
}
// Accounts for the offset adjustment before converting to absolute time.
if ((offset < 0 && cs > civil_second::max() + offset) ||
(offset > 0 && cs < civil_second::min() + offset)) {
if (err != nullptr) *err = "Out-of-range field";
return false;
}
cs -= offset;
const auto tp = ptz.lookup(cs).pre;
// Checks for overflow/underflow and returns an error as necessary.
if (tp == time_point<seconds>::max()) {
const auto al = ptz.lookup(time_point<seconds>::max());
if (cs > al.cs) {
if (err != nullptr) *err = "Out-of-range field";
return false;
}
}
if (tp == time_point<seconds>::min()) {
const auto al = ptz.lookup(time_point<seconds>::min());
if (cs < al.cs) {
if (err != nullptr) *err = "Out-of-range field";
return false;
}
}
*sec = tp;
*fs = subseconds;
return true;
}
} // namespace detail
} // namespace cctz
} // namespace time_internal
ABSL_NAMESPACE_END
} // namespace absl