Add simple benachmark for string builder
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#include "../conversion/stringbuilder.h"
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#include "../conversion/stringconversion.h"
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#include "../chrono/datetime.h"
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#include <vector>
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#include <iostream>
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#include <sstream>
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using namespace std;
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using namespace ConversionUtilities;
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using namespace ChronoUtilities;
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int main()
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{
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cout << "Benchmarking string builder vs. stringstream" << endl;
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constexpr unsigned int iterations = 500000;
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constexpr unsigned int iterations2 = 50;
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vector<string> v1, v2;
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v1.reserve(iterations);
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v2.reserve(iterations);
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DateTime t1 = DateTime::now();
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for(unsigned int r = 0; r < iterations2; ++r) {
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for(unsigned int i = 0; i < iterations; ++i) {
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stringstream ss;
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v1.emplace_back("left. " + numberToString(i + 1) + "; right: " + numberToString(i + 2) + "; top: " + numberToString(i + 3) + "; bottom: " + numberToString(i + 4) + ';');
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}
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v1.clear();
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}
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DateTime t2 = DateTime::now();
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cout << "plus operator: " << (t2 - t1).toString(TimeSpanOutputFormat::Normal, true) << endl;
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t1 = DateTime::now();
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for(unsigned int r = 0; r < iterations2; ++r) {
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for(unsigned int i = 0; i < iterations; ++i) {
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stringstream ss;
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ss << "left: " << (i + 1) << "; right: " << (i + 2) << "; top: " << (i + 3) << "; bottom: " << (i + 4) << ';';
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v1.emplace_back(ss.str());
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}
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v1.clear();
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}
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t2 = DateTime::now();
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const TimeSpan diff1 = t2 - t1;
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cout << "stringstream: " << diff1.toString(TimeSpanOutputFormat::Normal, true) << endl;
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t1 = DateTime::now();
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for(unsigned int r = 0; r < iterations2; ++r) {
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for(unsigned int i = 0; i < iterations; ++i) {
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v2.emplace_back("left. " % numberToString(i + 1) % "; right: " % numberToString(i + 2) % "; top: " % numberToString(i + 3) % "; bottom: " % numberToString(i + 4) + ';');
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}
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v2.clear();
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}
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t2 = DateTime::now();
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const TimeSpan diff2 = t2 - t1;
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cout << "string builder: " << diff2.toString(TimeSpanOutputFormat::Normal, true) << endl;
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v1.swap(v2);
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cout << "diff (stringstream minus string builder): " << (diff1 - diff2).toString(TimeSpanOutputFormat::Normal, true) << endl;
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cout << "factor (stringstream / string builder): " << (static_cast<double>(diff1.totalTicks()) / diff2.totalTicks()) << endl;
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return 0;
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}
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# Simple/stupid benchmarking
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Compares the string builder and numberToString() function as provided by c++utilities
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with std::stringstream (without reserving stringstream buffer).
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The string builder is actually just a fancy syntax for std::string::reserve()
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making its use more convenient.
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## Compile and run
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eg.
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```
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g++ -O3 stringbuilder-bench.cpp -o stringbuilder-bench-O3 -Wl,-rpath /lib/path -L /lib/path -lc++utilities
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./stringbuilder-bench-O3
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```
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## Results on my machine
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Results with -03:
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```
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plus operator: 00:00:17
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stringstream: 00:00:16
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string builder: 00:00:07
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diff (stringstream minus string builder): 00:00:09
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factor (stringstream / string builder): 2.28571
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```
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However, with -O0 4 times *slower*:
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```
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plus operator: 00:00:29
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stringstream: 00:00:16
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string builder: 00:01:04
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diff (stringstream minus string builder): - 00:35:22
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factor (stringstream / string builder): 0.25
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```
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Still 1.45 times faster than stringstream with -O2:
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```
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plus operator: 00:00:21
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stringstream: 00:00:16
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string builder: 00:00:11
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diff (stringstream minus string builder): 00:00:05
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factor (stringstream / string builder): 1.45455
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```
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So this basic tests show that string builder is up to 2 times faster when using full optimization
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and still 1.4 times faster when using -O2 (default under Arch Linux). However, this templating
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stuff completely relies on optimization (as expected). Results with clang++ where similar.
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