initial code repo

[stor4nfv.git] / src / ceph / src / common / iso_8601.cc

diff --git a/src/ceph/src/common/iso_8601.cc b/src/ceph/src/common/iso_8601.cc
new file mode 100644 (file)
index 0000000..39e00e0
--- /dev/null
+++ b/src/ceph/src/common/iso_8601.cc
@@ -0,0 +1,200 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "iso_8601.h"
+#include "include/timegm.h"
+
+#include <sstream>
+
+namespace ceph {
+using std::chrono::duration_cast;
+using std::chrono::nanoseconds;
+using std::chrono::seconds;
+using std::setw;
+using std::size_t;
+using std::stringstream;
+using std::string;
+using std::uint16_t;
+
+using boost::none;
+using boost::optional;
+using boost::string_ref;
+
+using ceph::real_clock;
+using ceph::real_time;
+
+using sriter = string_ref::const_iterator;
+
+namespace {
+// This assumes a contiguous block of numbers in the correct order.
+uint16_t digit(char c) {
+  if (!(c >= '0' && c <= '9')) {
+    throw std::invalid_argument("Not a digit.");
+  }
+  return static_cast<uint16_t>(c - '0');
+}
+
+optional<real_time> calculate(const tm& t, uint32_t n = 0) {
+  ceph_assert(n < 1000000000);
+  time_t tt = internal_timegm(&t);
+  if (tt == static_cast<time_t>(-1)) {
+    return none;
+  }
+
+  return boost::make_optional<real_time>(real_clock::from_time_t(tt)
+                                         + nanoseconds(n));
+}
+}
+
+optional<real_time> from_iso_8601(const string_ref s,
+                                 const bool ws_terminates) noexcept {
+  auto end = s.cend();
+  auto read_digit = [end](sriter& c) mutable {
+    if (c == end) {
+      throw std::invalid_argument("End of input.");
+    }
+    auto f = digit(*c);
+    ++c;
+    return f;
+  };
+
+  auto read_digits = [end, &read_digit](sriter& c, std::size_t n) {
+    auto v = 0ULL;
+    for (auto i = 0U; i < n; ++i) {
+      auto d = read_digit(c);
+      v = (10ULL * v) + d;
+    }
+    return v;
+  };
+  auto partial_date = [end, ws_terminates](sriter& c) {
+    return (c == end || (ws_terminates && std::isspace(*c)));
+  };
+  auto time_end = [end, ws_terminates](sriter& c) {
+    return (c != end && *c == 'Z' &&
+           ((c + 1) == end ||
+            (ws_terminates && std::isspace(*(c + 1)))));
+  };
+  auto consume_delimiter = [end](sriter& c, char q) {
+    if (c == end || *c != q) {
+      throw std::invalid_argument("Expected delimiter not found.");
+    } else {
+      ++c;
+    }
+  };
+
+  tm t = { 0, // tm_sec
+          0, // tm_min
+          0, // tm_hour
+          1, // tm_mday
+          0, // tm_mon
+          70, // tm_year
+          0, // tm_wday
+          0, // tm_yday
+          0, // tm_isdst
+  };
+  try {
+    auto c = s.cbegin();
+    {
+      auto y = read_digits(c, 4);
+      if (y < 1970) {
+       return none;
+      }
+      t.tm_year = y - 1900;
+    }
+    if (partial_date(c)) {
+      return calculate(t, 0);
+    }
+
+    consume_delimiter(c, '-');
+    t.tm_mon = (read_digits(c, 2) - 1);
+    if (partial_date(c)) {
+      return calculate(t);
+    }
+    consume_delimiter(c, '-');
+    t.tm_mday = read_digits(c, 2);
+    if (partial_date(c)) {
+      return calculate(t);
+    }
+    consume_delimiter(c, 'T');
+    t.tm_hour = read_digits(c, 2);
+    if (time_end(c)) {
+      return calculate(t);
+    }
+    consume_delimiter(c, ':');
+    t.tm_min = read_digits(c, 2);
+    if (time_end(c)) {
+      return calculate(t);
+    }
+    consume_delimiter(c, ':');
+    t.tm_sec = read_digits(c, 2);
+    if (time_end(c)) {
+      return calculate(t);
+    }
+    consume_delimiter(c, '.');
+
+    auto n = 0UL;
+    auto multiplier = 100000000UL;
+    for (auto i = 0U; i < 9U; ++i) {
+      auto d = read_digit(c);
+      n += d * multiplier;
+      multiplier /= 10;
+      if (time_end(c)) {
+       return calculate(t, n);
+      }
+    }
+  } catch (std::invalid_argument& e) {
+    // fallthrough
+  }
+  return none;
+}
+
+string to_iso_8601(const real_time t,
+                  const iso_8601_format f) noexcept {
+  ceph_assert(f >= iso_8601_format::Y &&
+             f <= iso_8601_format::YMDhmsn);
+  stringstream out(std::ios_base::out);
+
+  auto sec = real_clock::to_time_t(t);
+  auto nsec = duration_cast<nanoseconds>(t.time_since_epoch() %
+                                        seconds(1)).count();
+
+  struct tm bt;
+  gmtime_r(&sec, &bt);
+  out.fill('0');
+
+  out << 1900 + bt.tm_year;
+  if (f == iso_8601_format::Y) {
+    return out.str();
+  }
+
+  out << '-' << setw(2) << bt.tm_mon + 1;
+  if (f == iso_8601_format::YM) {
+    return out.str();
+  }
+
+  out << '-' << setw(2) << bt.tm_mday;
+  if (f == iso_8601_format::YMD) {
+    return out.str();
+  }
+
+  out << 'T' << setw(2) << bt.tm_hour;
+  if (f == iso_8601_format::YMDh) {
+    out << 'Z';
+    return out.str();
+  }
+
+  out << ':' << setw(2) << bt.tm_min;
+  if (f == iso_8601_format::YMDhm) {
+    out << 'Z';
+    return out.str();
+  }
+
+  out << ':' << setw(2) << bt.tm_sec;
+  if (f == iso_8601_format::YMDhms) {
+    out << 'Z';
+    return out.str();
+  }
+  out << '.' << setw(9) << nsec << 'Z';
+  return out.str();
+}
+}