From c26cf0efa7daa5116ca0f5d1cebdb750f9b459c7 Mon Sep 17 00:00:00 2001
From: Francesco Laurita <taganaka@gmail.com>
Date: Sun, 5 Jun 2016 23:34:03 -0700
Subject: [PATCH] Add support for Jitter measurement

---
 CMakeLists.txt |  2 +-
 README.md      |  4 +++-
 SpeedTest.cpp  | 22 ++++++++++++++++++++++
 SpeedTest.h    |  1 +
 main.cpp       |  3 ++-
 5 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b0d7500..89589a4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 2.6)
 project(SpeedTest)
 
 set (SpeedTest_VERSION_MAJOR 1)
-set (SpeedTest_VERSION_MINOR 0)
+set (SpeedTest_VERSION_MINOR 1)
 set (SpeedTest_SYSTEM_PROCESSOR ${CMAKE_SYSTEM_PROCESSOR})
 set (SpeedTest_SYSTEM ${CMAKE_SYSTEM})
 
diff --git a/README.md b/README.md
index 8af7500..557b3c7 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,9 @@ It supports the new (undocumented) raw TCP protocol for better accuracy.
 
 3. Aggressive multi-threading program in order to saturate your bandwidth quickly.
 
-4. Provide a URL to the speedtest.net share results image using option --share
+4. Test supported: Ping / Jitter / Download speed / Upload speed.
+
+5. Provide a URL to the speedtest.net share results image using option --share
 
 ## Installation
 
diff --git a/SpeedTest.cpp b/SpeedTest.cpp
index 245374d..6ee8e31 100644
--- a/SpeedTest.cpp
+++ b/SpeedTest.cpp
@@ -149,6 +149,27 @@ const double &SpeedTest::latency() {
     return mLatency;
 }
 
+const double SpeedTest::jitter(const ServerInfo &server, const int sample) {
+    auto client = SpeedTestClient(server);
+    double current_jitter = 0;
+    long previous_ms = -1;
+    if (client.connect()){
+        for (int i = 0; i < sample; i++){
+            long ms = 0;
+            if (client.ping(ms)){
+                if (previous_ms == -1) {
+                    previous_ms = ms;
+                } else {
+                    current_jitter += std::abs(previous_ms - ms);
+                }
+            }
+        }
+        client.close();
+    }
+
+    return std::floor(current_jitter / sample);
+}
+
 bool SpeedTest::share(const ServerInfo& server, std::string& image_url) {
     std::stringstream hash;
     hash << std::setprecision(0) << std::fixed << mLatency
@@ -415,3 +436,4 @@ ServerInfo SpeedTest::processServerXMLNode(xmlTextReaderPtr reader) {
     return ServerInfo();
 }
 
+
diff --git a/SpeedTest.h b/SpeedTest.h
index 9d25b8a..f3f6e12 100644
--- a/SpeedTest.h
+++ b/SpeedTest.h
@@ -67,6 +67,7 @@ class SpeedTest {
     const double &latency();
     const double downloadSpeed(const ServerInfo& server, const TestConfig& config);
     const double uploadSpeed(const ServerInfo& server, const TestConfig& config);
+    const double jitter(const ServerInfo& server, const int sample = 40);
     bool share(const ServerInfo& server, std::string& image_url);
 private:
     static CURL* curl_setup(CURL* curl = nullptr);
diff --git a/main.cpp b/main.cpp
index 8e7e3c6..e75310e 100644
--- a/main.cpp
+++ b/main.cpp
@@ -79,7 +79,8 @@ int main(const int argc, const char **argv) {
         << " by " << serverInfo.sponsor
         << " (" << serverInfo.distance << " km from you): "
         << sp.latency() << " ms" << std::endl;
-
+    std::cout << "Ping: " << sp.latency() << " ms." << std::endl;
+    std::cout << "Jitter: " << std::flush << sp.jitter(serverInfo) << " ms." << std::endl;
     if (latency_only)
         return EXIT_SUCCESS;