trunk/src/net/instaweb/util/time_util.cc

/**
 * Copyright 2010 Google Inc.
 *
 * 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
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.
 */

// Author: jmarantz@google.com (Joshua Marantz)

#include "net/instaweb/util/public/time_util.h"
#include <time.h>

#include "pagespeed/core/resource_util.h"

namespace net_instaweb {

bool ConvertTimeToString(int64 time_ms, std::string* time_string) {
  time_t time_sec = time_ms / 1000;
  struct tm time_buf;
  struct tm* time_info = gmtime_r(&time_sec, &time_buf);
  if ((time_info == NULL) ||
      (time_buf.tm_wday < 0) ||
      (time_buf.tm_wday > 6) ||
      (time_buf.tm_mon < 0) ||
      (time_buf.tm_mon > 11)) {
    return false;
  }

  static const char* kWeekDay[] = {
    "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
  static const char* kMonth[] = {
    "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov",
    "Dec"};

  // RFC 822 says to format like this:
  //                Thu Nov 18 02:15:22 2010 GMT
  // See http://www.faqs.org/rfcs/rfc822.html
  //
  // But redbot.org likes this:
  //    Wed, 24 Nov 2010 21:14:12 GMT
  *time_string = StringPrintf("%s, %02d %s %4d %02d:%02d:%02d GMT",
                              kWeekDay[time_buf.tm_wday],
                              time_buf.tm_mday,
                              kMonth[time_buf.tm_mon],
                              1900 + time_buf.tm_year,
                              time_buf.tm_hour,
                              time_buf.tm_min,
                              time_buf.tm_sec);
  return true;
}

bool ConvertStringToTime(const StringPiece& time_string, int64 *time_ms) {
  std::string buf(time_string.data(), time_string.size());
  return pagespeed::resource_util::ParseTimeValuedHeader(buf.c_str(), time_ms);
}

}  // namespace net_instaweb