use hugepages without size specification

hugepages can now be used without specifiying the exact size during the
use_hugepages() call. we now parse /proc/meminfo to determine the number
of hugepages available.

examples/hugepages.cpp

@@ -7,44 +7,38 @@ using namespace std;
 using namespace std::chrono;
 using timer = std::chrono::high_resolution_clock;
 
-template<class tCsa>
-void do_something(const tCsa& csa)
+template<class t_cst>
+void do_something(const t_cst& cst)
 {
     uint64_t sum=0;
     auto start = timer::now();
-    for (size_t i=0; i<csa.size() and i<10000000; ++i) {
-        sum+=csa.lf[i];
+    for (size_t i=0; i<cst.csa.size() and i<50000000; ++i) {
+        sum+=cst.csa.lf[i];
     }
     auto stop = timer::now();
-    cout << "runtime in s: " << duration_cast<seconds>(stop-start).count() << endl;
-    cout <<"sum="<<sum<<endl;
+    cout << "runtime in seconds: " << duration_cast<seconds>(stop-start).count() << endl;
+    cout << "sum="<<sum<<endl;
 }
 
 int main(int argc, char** argv)
 {
     if (argc < 2) {
-        cout << "Usage: " << argv[0] << " file" << endl;
+        cout << "Usage: " << argv[0] << " file <use_hugepages>" << endl;
         cout << " (1) Creates a CST for a byte file. " << endl;
-        cout << " (2) Runs a benchmark with enabled/disabled 1GB=hugepages." << endl;
+        cout << " (2) Runs a benchmark with enabled/disabled hugepages." << endl;
         return 1;
     }
 
     if (argc==3) {
-        memory_manager::use_hugepages(500*1024*1024);
+        // memory_manager::use_hugepages(500ULL*1024ULL*1024ULL);
+        // use all available hugepages if nothing is specified
+        memory_manager::use_hugepages();
     }
 
-    memory_monitor::start();
-
-    csa_wt<> csa;
+    cst_sct3<> cst;
     auto start = timer::now();
-    construct(csa, argv[1], 1);
+    construct(cst, argv[1], 1);
     auto stop = timer::now();
-    cout << "construction in s: " << duration_cast<seconds>(stop-start).count() << endl;
-    do_something(csa); // before it is mapped
-
-    memory_monitor::stop();
-
-    std::ofstream ofs("cst-construction.json");
-    memory_monitor::write_memory_log<JSON>(ofs);
-    ofs.close();
+    cout << "construction time in seconds: " << duration_cast<seconds>(stop-start).count() << endl;
+    do_something(cst); // before it is mapped
 }