sysrap/tests/stamp_test.cc

0001 // ./stamp_test.sh
0002
0003 #include <chrono>
0004 #include <iostream>
0005 #include <iomanip>
0006
0007 #include "stamp.h"
0008 #include "NP.hh"
0009
0010
0011 /**
0012 test_reverse
0013 -------------
0014
0015 1. creates uint64_t timestamp t0 using stamp::Now
0016 2. uses that integer to create std::chrono::time_point and gets the count
0017 3. asserts that they match
0018
0019 Success of this test means can safely store time stamps at uint64_t values
0020
0021 **/
0022
0023 void test_reverse()
0024 {
0025     std::cout << std::endl << "test_reverse " << std::endl ;
0026     uint64_t t0 = stamp::Now();
0027
0028     using Clock = std::chrono::system_clock;
0029     using Unit  = std::chrono::microseconds  ;
0030
0031     std::chrono::time_point<Clock> t0_{Unit{t0}} ;
0032     uint64_t t1 = std::chrono::duration_cast<Unit>(t0_.time_since_epoch()).count() ;
0033
0034     std::cout << "t0: " << t0 <<  std::endl ;
0035     std::cout << "t1: " << t1 <<  std::endl ;
0036
0037     assert( t0 == t1 ) ;
0038 }
0039
0040
0041 /**
0042 test_performance
0043 ----------------
0044
0045 1. creates an array able to hold 25 million uint64_t values
0046 2. fills the array with timestamps
0047 3. saves the array to filepath $FOLD/tt.npy
0048
0049 On old laptop: counting and stamp recording to 25M takes roughly 1s (1M us)
0050 so 25 stamp records takes ~1us
0051 (microsecond, 10-6 second, one millionth of a second)
0052
0053 **/
0054
0055 void test_performance()
0056 {
0057     static const int N = 1000000*25 ;
0058     const char* ttpath = "$FOLD/tt.npy" ;
0059
0060     std::cout << std::endl << "test_performance : N " << N  << " : save stamps to ttpath " << ttpath << std::endl ;
0061
0062     NP* t = NP::Make<uint64_t>(N) ;
0063     uint64_t* tt = t->values<uint64_t>();
0064     for(int i=0 ; i < N ; i++) tt[i] = stamp::Now();
0065
0066     t->set_meta<std::string>("IDENTITY", U::GetEnv("IDENTITY", "no-IDENTITY") );
0067     t->save(ttpath);
0068 }
0069
0070 /**
0071 test_format
0072 -------------
0073
0074 1. create timestamp uint64_t
0075 2. exercise stamp::Format using that timestamp and other values
0076
0077 **/
0078
0079
0080 void test_format()
0081 {
0082     std::cout << std::endl << "test_format" << std::endl ;
0083     uint64_t t0 = stamp::Now();
0084     std::cout << t0 << " : " << stamp::Format(t0) << " " << stamp::Format() << std::endl ;
0085
0086     std::cout << "stamp::Format()             " << stamp::Format() << std::endl;
0087     std::cout << "stamp::Format(stamp::Now()) " << stamp::Format(stamp::Now()) << std::endl;
0088     std::cout << "stamp::Format(0)            " << stamp::Format(0) << std::endl;
0089     std::cout << "stamp::Format(1)            " << stamp::Format(1) << std::endl;
0090     std::cout << "stamp::Format(1000)         " << stamp::Format(1000) << std::endl;
0091     std::cout << "stamp::Format(1000000)      " << stamp::Format(1000000) << std::endl;
0092     std::cout << "NOTE TIMEZONE LOCALIZATION OF THE ASSUMED UTC STAMPS" << std::endl ;
0093
0094     for(int i=0 ; i < 10 ; i++)
0095     {
0096         uint64_t t = stamp::Now();
0097         std::cout << std::setw(5) << i << " : " << stamp::Format(t) << std::setw(9) << (t - t0) << std::endl ;
0098     }
0099 }
0100
0101
0102 int main()
0103 {
0104     test_reverse();
0105     test_performance();
0106     test_format();
0107     return 0 ;
0108 }
0109