#ifndef CXX_UTIL_STOPWATCH_H
#define CXX_UTIL_STOPWATCH_H

#include <sys/time.h>

namespace util {

class stopwatch
{
public:
    typedef long long usec_t;
    
    stopwatch() 
        : start_(now()) 
    {}
        
    usec_t elapsed() const 
    { 
        return now() - start_; 
    }

    usec_t reset()
    {
        usec_t t(now());
        usec_t r(t - start_);
        start_ = t;
        return r;
    }

private:
    static usec_t now()
    {
        timeval t;
        ::gettimeofday(&t, 0);
        return 1000000LL * t.tv_sec + t.tv_usec;
    }

private:
    usec_t start_;
};

} // namespace util

#endif // CXX_UTIL_STOPWATCH_H