text: /*
   * libjingle
   * Copyright 2004--2005, Google Inc.
   *
   * Redistribution and use in source and binary forms, with or without 
   * modification, are permitted provided that the following conditions are met:
   *
   *  1. Redistributions of source code must retain the above copyright notice, 
   *     this list of conditions and the following disclaimer.
   *  2. Redistributions in binary form must reproduce the above copyright notice,
   *     this list of conditions and the following disclaimer in the documentation
   *     and/or other materials provided with the distribution.
   *  3. The name of the author may not be used to endorse or promote products 
   *     derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
   * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
   * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 
   * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <iostream>
  #include <cstdlib>
  #include <cstring>
  
  #include "talk/base/time.h"
  
  namespace talk_base {
  
  #ifdef POSIX
  #include <sys/time.h>
  uint32 Time() {
    struct timeval tv;
    gettimeofday(&tv, 0);
    return tv.tv_sec * 1000 + tv.tv_usec / 1000;
  }
  #endif
  
  #ifdef WIN32
  #include <windows.h>
  uint32 Time() {
    return GetTickCount();
  }
  #endif
  
  uint32 StartTime() {
    // Close to program execution time
    static const uint32 g_start = Time();
    return g_start;
  }
  
  // Make sure someone calls it so that it gets initialized
  static uint32 ignore = StartTime();
  
  uint32 ElapsedTime() {
    return TimeDiff(Time(), StartTime());
  }
  
  bool TimeIsBetween(uint32 later, uint32 middle, uint32 earlier) {
    if (earlier <= later) {
      return ((earlier <= middle) && (middle <= later));
    } else {
      return !((later < middle) && (middle < earlier));
    }
  }
  
  int32 TimeDiff(uint32 later, uint32 earlier) {
    uint32 LAST = 0xFFFFFFFF;
    uint32 HALF = 0x80000000;
    if (TimeIsBetween(earlier + HALF, later, earlier)) {
      if (earlier <= later) {
        return static_cast<long>(later - earlier);
      } else {
        return static_cast<long>(later + (LAST - earlier) + 1);
      }
    } else {
      if (later <= earlier) {
        return -static_cast<long>(earlier - later);
      } else {
        return -static_cast<long>(earlier + (LAST - later) + 1);
      }
    }
  }
  
  } // namespace talk_base
  