add more control from the command line options

Author: ahmedakef

main.cpp

@@ -11,27 +11,29 @@ namespace po = boost::program_options;
 using namespace std;
 bool continue_reading = true;
 
-void handle_printing(Summarizer *summarizer, int delay)
+void handle_printing(Summarizer *summarizer, int delay, int precision)
 {
-    printElements(vector<string>{"Average", "Min", "Median", "p95", "p99", "Max", "\n"});
+    printElements(vector<string>{"Average", "Min", "Median", "p95", "p99", "Max", "\n"}, precision);
     while (true)
     {
         cout << "\r";
-        summarizer->print_summery();
+        summarizer->print_summery(precision);
         this_thread::sleep_for(chrono::seconds(delay));
-        if (continue_reading == false){
-            cout<<endl;
+        if (continue_reading == false)
+        {
+            cout << endl;
             break;
         }
     }
 }
 
-void start(int delay) {
+void start(int delay, int precision)
+{
     int number;
     string line;
     Summarizer summarizer;
 
-    thread timer(handle_printing, &summarizer, delay);
+    thread timer(handle_printing, &summarizer, delay, precision);
 
     while (continue_reading)
     {
@@ -52,49 +54,60 @@ void start(int delay) {
     timer.join();
 }
 
-int main(int ac, char* av[])
+int main(int ac, char *av[])
 {
-    try {
+    int delay, precision;
+
+    try
+    {
         po::options_description desc("Allowed options");
         desc.add_options()
             ("help,h", "produce help message")
             ("file,f", po::value<string>(), "read input from a file")
-            ("delay,d", po::value<int>(), "delay time between re-calculating")
+            ("delay,d", po::value<int>(&delay)->default_value(1), "delay time between re-calculating")
+            ("precision,p", po::value<int>(&precision)->default_value(2), "control the precision parameter")
         ;
 
-        po::variables_map vm;        
-        po::store(po::parse_command_line(ac, av, desc), vm);
-        po::notify(vm); 
+        po::positional_options_description p;
+        p.add("file", 1);
+
+        po::variables_map vm;
+        po::store(po::command_line_parser(ac, av).
+                  options(desc).positional(p).run(), vm);
+        po::notify(vm);
 
-        if (vm.count("help")) {
+        if (vm.count("help"))
+        {
+            cout << "summarizer - Summarize a stream of numbers by printing some aggregation functions every specified interval\n";
+            cout << "Usage: summarizer [file_name] [options]\n";
             cout << desc << "\n";
             return 0;
         }
 
-        if (vm.count("file")) {
+        if (vm.count("file"))
+        {
             string file_name = vm["file"].as<string>();
             // close the stdin so when we open the file it take the lowest
             // available file descriptor which is 0
             close(0);
             int fd = open(file_name.c_str(), 0);
-            if (fd < 0) {
-                cout<<"cat: cannot open "<<file_name<<endl;
+            if (fd < 0)
+            {
+                cout << "cat: cannot open " << file_name << endl;
                 exit(1);
             }
-            
-        }
-        int delay = 1;
-        if (vm.count("delay")) {
-            delay = vm["delay"].as<int>();
         }
-        start(delay);
-    } catch(exception& e) {
+        start(delay, precision);
+    }
+    catch (exception &e)
+    {
         cerr << "Error: " << e.what() << "\n";
         return 1;
     }
-    catch(...) {
+    catch (...)
+    {
         cerr << "Exception of unknown type!\n";
     }
-    
+
     return 0;
 }

modules/summarizer.cpp

@@ -17,7 +17,7 @@ void Summarizer::add_number(double number)
     numbers.insert(number);
 }
 
-void Summarizer::print_summery()
+void Summarizer::print_summery(int precision)
 {
     double count = numbers.size();
     double average = sum / count;
@@ -37,5 +37,5 @@ void Summarizer::print_summery()
     // maximum exists at the end of the set: 0+50+45+4+1 = 100
     std::advance(it, 0.01 * count);
     double maximum = *it;
-    printElements(vector<double>{average, min, median, p95, p99, maximum});
+    printElements(vector<double>{average, min, median, p95, p99, maximum}, precision);
 }

modules/summarizer.hpp

@@ -11,7 +11,7 @@ class Summarizer
 public:
   Summarizer();
   void add_number(double number);
-  void print_summery();
+  void print_summery(int precision);
 };
 
 #endif

utils/utils.cpp

@@ -7,22 +7,22 @@
 using namespace std;
 
 template <typename T>
-void printElement(T t)
+void printElement(T t, int precision)
 {
-    cout << left << setw(10) << fixed << setprecision(2) << t;
+    cout << left << setw(10) << fixed << setprecision(precision) << t;
 }
 
 
 template<typename T> 
-void printElements(vector<T> elements)
+void printElements(vector<T> elements, int precision)
 {
     for( auto element : elements )
     {
-        printElement(element);
+        printElement(element, precision);
     }
 }
-template void printElements(vector<double> elements);
-template void printElements(vector<string> elements);
+template void printElements(vector<double> elements, int precision);
+template void printElements(vector<string> elements, int precision);
 
 
 

utils/utils.hpp

@@ -7,10 +7,10 @@
 using namespace std;
 
 template <typename T>
-void printElement(T t);
+void printElement(T t, int precision);
 
 template<typename T>
-void printElements(vector<T> elements);
+void printElements(vector<T> elements, int precision);
 
 bool is_number(const string &s);