intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 39 insertions, 0 deletions

diff --git a/library/cpp/lwtrace/example1/lwtrace_example1.cpp b/library/cpp/lwtrace/example1/lwtrace_example1.cpp
new file mode 100644
index 0000000000..6b32c405ee
--- /dev/null
+++ b/library/cpp/lwtrace/example1/lwtrace_example1.cpp
@@ -0,0 +1,39 @@
+#include <library/cpp/lwtrace/all.h>
+
+#define LWTRACE_EXAMPLE_PROVIDER(PROBE, EVENT, GROUPS, TYPES, NAMES)          \
+    PROBE(IterationProbe, GROUPS(), TYPES(i32, double), NAMES("n", "result")) \
+    /**/
+
+LWTRACE_DECLARE_PROVIDER(LWTRACE_EXAMPLE_PROVIDER)
+LWTRACE_DEFINE_PROVIDER(LWTRACE_EXAMPLE_PROVIDER)
+
+void InitLWTrace() {
+    NLWTrace::StartLwtraceFromEnv();
+}
+
+long double Fact(int n) {
+    if (n < 0) {
+        ythrow yexception() << "N! is undefined for negative N (" << n << ")";
+    }
+    double result = 1;
+    for (; n > 1; --n) {
+        GLOBAL_LWPROBE(LWTRACE_EXAMPLE_PROVIDER, IterationProbe, n, result);
+        result *= n;
+    }
+    return result;
+}
+
+void FactorialCalculator() {
+    i32 n;
+    Cout << "Enter a number: ";
+    TString str;
+    Cin >> n;
+    double factN = Fact(n);
+    Cout << n << "! = " << factN << Endl << Endl;
+}
+
+int main() {
+    InitLWTrace();
+    FactorialCalculator();
+    return 0;
+}