plugins: add log streaming

examples/CMakeLists.txt

@@ -25,6 +25,7 @@ add_subdirectory(geofence)
 add_subdirectory(gimbal)
 add_subdirectory(gimbal_device_tester)
 add_subdirectory(logfile_download)
+add_subdirectory(log_streaming)
 add_subdirectory(manual_control)
 add_subdirectory(mavshell)
 add_subdirectory(multiple_drones)

examples/log_streaming/CMakeLists.txt

@@ -0,0 +1,22 @@
+cmake_minimum_required(VERSION 3.10.2)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+project(log_streaming)
+
+add_executable(log_streaming
+    log_streaming.cpp
+)
+
+find_package(MAVSDK REQUIRED)
+
+target_link_libraries(log_streaming
+    MAVSDK::mavsdk
+)
+
+if(NOT MSVC)
+    add_compile_options(log_streaming PRIVATE -Wall -Wextra)
+else()
+    add_compile_options(log_streaming PRIVATE -WX -W2)
+endif()

examples/log_streaming/log_streaming.cpp

@@ -0,0 +1,130 @@
+//
+// Example how to stream ulog from PX4 with MAVSDK.
+//
+
+#include <mavsdk/mavsdk.h>
+#include <mavsdk/base64.h>
+#include <mavsdk/plugins/log_streaming/log_streaming.h>
+
+#include <chrono>
+#include <iostream>
+#include <thread>
+#include <fstream>
+#include <iomanip>
+#include <sstream>
+
+using namespace mavsdk;
+using std::chrono::seconds;
+using std::this_thread::sleep_for;
+
+void usage(const std::string& bin_name)
+{
+    std::cerr << "Usage : " << bin_name << " <connection_url> [--rm]\n"
+              << '\n'
+              << "Connection URL format should be :\n"
+              << " For TCP : tcp://[server_host][:server_port]\n"
+              << " For UDP : udp://[bind_host][:bind_port]\n"
+              << " For Serial : serial:///path/to/serial/dev[:baudrate]\n"
+              << "For example, to connect to the simulator use URL: udp://:14540" << std::endl;
+}
+
+int main(int argc, char** argv)
+{
+    if (argc > 2) {
+        usage(argv[0]);
+        return 1;
+    }
+
+    Mavsdk mavsdk{Mavsdk::Configuration{Mavsdk::ComponentType::GroundStation}};
+    ConnectionResult connection_result = mavsdk.add_any_connection(argv[1]);
+
+    if (connection_result != ConnectionResult::Success) {
+        std::cerr << "Connection failed: " << connection_result << std::endl;
+        return 1;
+    }
+
+    auto system = mavsdk.first_autopilot(3.0);
+    if (!system) {
+        std::cerr << "Timed out waiting for system\n";
+        return 1;
+    }
+
+    // Create file to log to.
+    // Get current time
+    auto now = std::chrono::system_clock::now();
+    auto in_time_t = std::chrono::system_clock::to_time_t(now);
+
+    // Convert time_t to tm struct
+    struct tm buf;
+    localtime_r(&in_time_t, &buf);
+
+    // Create a stringstream to hold the filename
+    std::stringstream ss;
+
+    // Format the time into the stringstream
+    ss << std::put_time(&buf, "%Y-%m-%d_%H-%M-%S") << ".ulg";
+
+    // Convert stringstream to string to use as filename
+    std::string filename = ss.str();
+
+    // Open the file
+    std::ofstream file(filename, std::ios::binary);
+
+    if (!file.is_open()) {
+        std::cerr << "Could not open file with name '" << ss.str() << "'";
+        return 1;
+    }
+
+    // Instantiate plugins.
+    auto log_streaming = LogStreaming{system.value()};
+
+    size_t bytes_written = 0;
+    size_t bytes_written_since_last = 0;
+    auto last_time = std::chrono::steady_clock::now();
+
+    log_streaming.subscribe_log_streaming_raw([&](LogStreaming::LogStreamingRaw raw) {
+        const auto bytes = mavsdk::base64_decode(raw.data);
+        file.write(reinterpret_cast<const char*>(bytes.data()), bytes.size());
+        bytes_written += bytes.size();
+        bytes_written_since_last += bytes.size();
+
+        auto now = std::chrono::steady_clock::now();
+        std::chrono::duration<double> elapsed = now - last_time;
+
+        if (elapsed.count() >= 1.0) {
+            // More than or equal to one second has passed
+            double seconds = elapsed.count();
+            double rate_kib_per_second = (bytes_written_since_last / 1024.0) / seconds;
+
+            std::cout << "Wrote " << std::setprecision(3) << bytes_written / 1024.0 / 1024.0
+                      << " MiB (" << rate_kib_per_second << " KiB/s)" << std::endl;
+
+            // Reset timer and counter
+            last_time = now;
+            bytes_written_since_last = 0;
+        }
+    });
+
+    auto result = log_streaming.start_log_streaming();
+    if (result != LogStreaming::Result::Success) {
+        std::cerr << "Log streaming start failed." << std::endl;
+        return 1;
+    }
+
+    for (unsigned i = 0; i < 10; ++i) {
+        std::this_thread::sleep_for(std::chrono::seconds(1));
+    }
+
+    result = log_streaming.stop_log_streaming();
+    if (result != LogStreaming::Result::Success) {
+        std::cerr << "Log streaming stop failed." << std::endl;
+        return 1;
+    }
+
+    // Give it time to wrap up all logging data
+    std::this_thread::sleep_for(std::chrono::seconds(3));
+
+    file.close();
+
+    return 0;
+}

src/mavsdk/core/CMakeLists.txt

@@ -14,6 +14,7 @@ configure_file(include/mavsdk/mavlink_include.h.in include/mavsdk/mavlink_includ
 
 target_sources(mavsdk
     PRIVATE
+    base64.cpp
     call_every_handler.cpp
     connection.cpp
     connection_result.cpp
@@ -150,6 +151,7 @@ install(TARGETS mavsdk
 
 install(FILES
     include/mavsdk/autopilot.h
+    include/mavsdk/base64.h
     include/mavsdk/connection_result.h
     include/mavsdk/deprecated.h
     include/mavsdk/handle.h

src/mavsdk/core/base64.cpp

@@ -0,0 +1,102 @@
+#include "base64.h"
+
+namespace mavsdk {
+
+static const std::string base64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                                        "abcdefghijklmnopqrstuvwxyz"
+                                        "0123456789+/";
+
+static inline bool is_base64(uint8_t c)
+{
+    return (isalnum(c) || (c == '+') || (c == '/'));
+}
+
+std::string base64_encode(std::vector<uint8_t>& raw)
+{
+    uint8_t* buf = raw.data();
+    size_t bufLen = raw.size();
+
+    std::string ret;
+    int i = 0;
+    int j = 0;
+    uint8_t char_array_3[3];
+    uint8_t char_array_4[4];
+
+    while (bufLen--) {
+        char_array_3[i++] = *(buf++);
+        if (i == 3) {
+            char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+            char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+            char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+            char_array_4[3] = char_array_3[2] & 0x3f;
+
+            for (i = 0; (i < 4); i++)
+                ret += base64_chars[char_array_4[i]];
+            i = 0;
+        }
+    }
+
+    if (i) {
+        for (j = i; j < 3; j++)
+            char_array_3[j] = '\0';
+
+        char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+        char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+        char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+        char_array_4[3] = char_array_3[2] & 0x3f;
+
+        for (j = 0; (j < i + 1); j++)
+            ret += base64_chars[char_array_4[j]];
+
+        while ((i++ < 3))
+            ret += '=';
+    }
+
+    return ret;
+}
+
+std::vector<uint8_t> base64_decode(std::string const& encoded_string)
+{
+    int in_len = encoded_string.size();
+    int i = 0;
+    int j = 0;
+    int in_ = 0;
+    uint8_t char_array_4[4], char_array_3[3];
+    std::vector<uint8_t> ret;
+
+    while (in_len-- && (encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
+        char_array_4[i++] = encoded_string[in_];
+        in_++;
+        if (i == 4) {
+            for (i = 0; i < 4; i++)
+                char_array_4[i] = base64_chars.find(char_array_4[i]);
+
+            char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
+            char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+            char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
+
+            for (i = 0; (i < 3); i++)
+                ret.push_back(char_array_3[i]);
+            i = 0;
+        }
+    }
+
+    if (i) {
+        for (j = i; j < 4; j++)
+            char_array_4[j] = 0;
+
+        for (j = 0; j < 4; j++)
+            char_array_4[j] = base64_chars.find(char_array_4[j]);
+
+        char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
+        char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+        char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
+
+        for (j = 0; (j < i - 1); j++)
+            ret.push_back(char_array_3[j]);
+    }
+
+    return ret;
+}
+
+} // namespace mavsdk

src/mavsdk/core/callback_list_impl.h

@@ -100,7 +100,7 @@ template<typename... Args> class CallbackListImpl {
     {
         std::lock_guard<std::mutex> remove_later_lock(_remove_later_mutex);
 
-        // We could probably just grab the lock here but it's safer not to
+        // We could probably just grab the lock here, but it's safer not to
         // acquire both locks to avoid deadlocks.
         if (_mutex.try_lock()) {
             if (_remove_all_later) {

src/mavsdk/core/include/mavsdk/base64.h

@@ -0,0 +1,12 @@
+#include <cstdint>
+#include <vector>
+#include <string>
+
+// Taken from https://stackoverflow.com/a/13935718/8548472
+
+namespace mavsdk {
+
+std::string base64_encode(std::vector<uint8_t>& raw);
+std::vector<uint8_t> base64_decode(const std::string& str);
+
+} // namespace mavsdk

src/mavsdk/core/log.cpp

@@ -25,6 +25,11 @@ namespace mavsdk {
 static std::mutex callback_mutex_{};
 static log::Callback callback_{nullptr};
 
+std::ostream& operator<<(std::ostream& os, std::byte b)
+{
+    return os << std::bitset<8>(std::to_integer<int>(b));
+}
+
 log::Callback& log::get_callback()
 {
     std::lock_guard<std::mutex> lock(callback_mutex_);

src/mavsdk/core/log.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <bitset>
+#include <cstddef>
 #include <mutex>
 #include <sstream>
 #include "log_callback.h"
@@ -30,6 +32,8 @@ namespace mavsdk {
 
 static std::mutex log_mutex_{};
 
+std::ostream& operator<<(std::ostream& os, std::byte b);
+
 enum class Color { Red, Green, Yellow, Blue, Gray, Reset };
 
 void set_color(Color color);

src/mavsdk/plugins/log_streaming/CMakeLists.txt

@@ -0,0 +1,15 @@
+target_sources(mavsdk
+    PRIVATE
+    log_streaming.cpp
+    log_streaming_impl.cpp
+)
+
+target_include_directories(mavsdk PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:include/mavsdk>
+    )
+
+install(FILES
+    include/plugins/log_streaming/log_streaming.h
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/mavsdk/plugins/log_streaming
+)