param_server: implemented change_param_? functions

examples/autopilot_server/autopilot_server.cpp

@@ -3,7 +3,6 @@
 #include <thread>
 
 #include <mavsdk/mavsdk.h>
-#include <mavsdk/plugins/mavlink_passthrough/mavlink_passthrough.h>
 #include <mavsdk/plugins/telemetry/telemetry.h>
 #include <mavsdk/plugins/action/action.h>
 #include <mavsdk/plugins/param_server/param_server.h>
@@ -83,7 +82,8 @@ int main(int argc, char** argv)
         paramServer.provide_param_int("SYS_HITL", 0);
         paramServer.provide_param_int("MIS_TAKEOFF_ALT", 0);
         // Add a custom param
-        paramServer.provide_param_int("my_param", 1);
+        paramServer.provide_param_int("MY_PARAM", 1);
+        paramServer.change_param_int("MY_PARAM", 2);
 
         // Allow the vehicle to change modes, takeoff and arm
         actionServer.set_allowable_flight_modes({true, true, true});

src/mavsdk/core/mavlink_parameter_server.cpp

@@ -179,6 +179,71 @@ MavlinkParameterServer::retrieve_server_param_int(const std::string& name)
     return retrieve_server_param<int32_t>(name);
 }
 
+MavlinkParameterServer::Result
+MavlinkParameterServer::change_server_param(const std::string& name, const ParamValue& param_value)
+{
+    if (name.size() > PARAM_ID_LEN) {
+        LogErr() << "Error: param name too long";
+        return Result::ParamNameTooLong;
+    }
+    const auto param_opt = _param_cache.param_by_id(name, true);
+    if (!param_opt.has_value()) {
+        return Result::NotFound;
+    }
+    // This parameter exists, check its type
+    const auto& param = param_opt.value();
+    if (!param.value.is_same_type(param_value)) {
+        return Result::WrongType;
+    }
+
+    if (param_value.is<std::string>()) {
+        const auto s = param_value.get<std::string>();
+        if (s.size() > sizeof(mavlink_param_ext_set_t::param_value)) {
+            LogErr() << "Error: param value too long";
+            return Result::ParamValueTooLong;
+        }
+    }
+    std::lock_guard<std::mutex> lock(_all_params_mutex);
+    // then, to not change the public api behaviour, try updating its value.
+    switch (_param_cache.update_existing_param(name, param_value)) {
+        case MavlinkParameterCache::UpdateExistingParamResult::Ok:
+            return Result::Success;
+        case MavlinkParameterCache::UpdateExistingParamResult::MissingParam:
+            return Result::ParamNotFound;
+        case MavlinkParameterCache::UpdateExistingParamResult::WrongType:
+            return Result::WrongType;
+        default:
+            LogErr() << "Unknown update_existing_param result";
+            assert(false);
+    }
+
+    return Result::Unknown;
+}
+
+MavlinkParameterServer::Result
+MavlinkParameterServer::change_server_param_float(const std::string& name, float value)
+{
+    ParamValue param_value;
+    param_value.set(value);
+    return change_server_param(name, param_value);
+}
+
+MavlinkParameterServer::Result
+MavlinkParameterServer::change_server_param_int(const std::string& name, int32_t value)
+{
+    ParamValue param_value;
+    param_value.set(value);
+    return change_server_param(name, param_value);
+}
+
+MavlinkParameterServer::Result MavlinkParameterServer::change_server_param_custom(
+    const std::string& name, const std::string& value)
+{
+    ParamValue param_value;
+    param_value.set(value);
+    return change_server_param(name, param_value);
+}
+
 void MavlinkParameterServer::process_param_set_internally(
     const std::string& param_id, const ParamValue& value_to_set, bool extended)
 {

src/mavsdk/core/mavlink_parameter_server.h

@@ -55,6 +55,11 @@ class MavlinkParameterServer : public MavlinkParameterSubscription {
     std::pair<Result, int32_t> retrieve_server_param_int(const std::string& name);
     std::pair<Result, std::string> retrieve_server_param_custom(const std::string& name);
 
+    Result change_server_param(const std::string& name, const ParamValue& param_value);
+    Result change_server_param_float(const std::string& name, float value);
+    Result change_server_param_int(const std::string& name, int32_t value);
+    Result change_server_param_custom(const std::string& name, const std::string& value);
+
     void do_work();
 
     friend std::ostream& operator<<(std::ostream&, const Result&);

src/mavsdk/plugins/param_server/include/plugins/param_server/param_server.h

@@ -186,6 +186,17 @@ class ParamServer : public ServerPluginBase {
      */
     Result provide_param_int(std::string name, int32_t value) const;
 
+    /**
+     * @brief Change an int parameter internally.
+     *
+     * If the type is wrong, the result will be `WRONG_TYPE`.
+     *
+     * This function is blocking.
+     *
+     * @return Result of request.
+     */
+    Result change_param_int(std::string name, int32_t value) const;
+
     /**
      * @brief Retrieve a float parameter.
      *
@@ -208,6 +219,17 @@ class ParamServer : public ServerPluginBase {
      */
     Result provide_param_float(std::string name, float value) const;
 
+    /**
+     * @brief Change a float parameter internally.
+     *
+     * If the type is wrong, the result will be `WRONG_TYPE`.
+     *
+     * This function is blocking.
+     *
+     * @return Result of request.
+     */
+    Result change_param_float(std::string name, float value) const;
+
     /**
      * @brief Retrieve a custom parameter.
      *
@@ -230,6 +252,17 @@ class ParamServer : public ServerPluginBase {
      */
     Result provide_param_custom(std::string name, std::string value) const;
 
+    /**
+     * @brief Change a custom parameter internally.
+     *
+     * If the type is wrong, the result will be `WRONG_TYPE`.
+     *
+     * This function is blocking.
+     *
+     * @return Result of request.
+     */
+    Result change_param_custom(std::string name, std::string value) const;
+
     /**
      * @brief Retrieve all parameters.
      *

src/mavsdk/plugins/param_server/param_server.cpp

@@ -31,6 +31,11 @@ ParamServer::Result ParamServer::provide_param_int(std::string name, int32_t val
     return _impl->provide_param_int(name, value);
 }
 
+ParamServer::Result ParamServer::change_param_int(std::string name, int32_t value) const
+{
+    return _impl->change_param_int(name, value);
+}
+
 std::pair<ParamServer::Result, float> ParamServer::retrieve_param_float(std::string name) const
 {
     return _impl->retrieve_param_float(name);
@@ -41,6 +46,11 @@ ParamServer::Result ParamServer::provide_param_float(std::string name, float val
     return _impl->provide_param_float(name, value);
 }
 
+ParamServer::Result ParamServer::change_param_float(std::string name, float value) const
+{
+    return _impl->change_param_float(name, value);
+}
+
 std::pair<ParamServer::Result, std::string>
 ParamServer::retrieve_param_custom(std::string name) const
 {
@@ -52,6 +62,11 @@ ParamServer::Result ParamServer::provide_param_custom(std::string name, std::str
     return _impl->provide_param_custom(name, value);
 }
 
+ParamServer::Result ParamServer::change_param_custom(std::string name, std::string value) const
+{
+    return _impl->change_param_custom(name, value);
+}
+
 ParamServer::AllParams ParamServer::retrieve_all_params() const
 {
     return _impl->retrieve_all_params();

src/mavsdk/plugins/param_server/param_server_impl.cpp

@@ -39,6 +39,22 @@ ParamServer::Result ParamServerImpl::provide_param_int(std::string name, int32_t
     return ParamServer::Result::Success;
 }
 
+ParamServer::Result ParamServerImpl::change_param_int(std::string name, int32_t value)
+{
+    if (name.size() > 16) {
+        return ParamServer::Result::ParamNameTooLong;
+    }
+
+    const auto result =
+        _server_component_impl->mavlink_parameter_server().change_server_param_int(name, value);
+
+    if (result == MavlinkParameterServer::Result::Success) {
+        return ParamServer::Result::Success;
+    } else {
+        return ParamServer::Result::NotFound;
+    }
+}
+
 std::pair<ParamServer::Result, float> ParamServerImpl::retrieve_param_float(std::string name) const
 {
     const auto result =
@@ -60,6 +76,22 @@ ParamServer::Result ParamServerImpl::provide_param_float(std::string name, float
     return ParamServer::Result::Success;
 }
 
+ParamServer::Result ParamServerImpl::change_param_float(std::string name, float value)
+{
+    if (name.size() > 16) {
+        return ParamServer::Result::ParamNameTooLong;
+    }
+
+    const auto result =
+        _server_component_impl->mavlink_parameter_server().change_server_param_float(name, value);
+
+    if (result == MavlinkParameterServer::Result::Success) {
+        return ParamServer::Result::Success;
+    } else {
+        return ParamServer::Result::NotFound;
+    }
+}
+
 std::pair<ParamServer::Result, std::string>
 ParamServerImpl::retrieve_param_custom(std::string name) const
 {
@@ -83,6 +115,22 @@ ParamServerImpl::provide_param_custom(std::string name, const std::string& value
     return ParamServer::Result::Success;
 }
 
+ParamServer::Result ParamServerImpl::change_param_custom(std::string name, const std::string& value)
+{
+    if (name.size() > 16) {
+        return ParamServer::Result::ParamNameTooLong;
+    }
+
+    const auto result =
+        _server_component_impl->mavlink_parameter_server().change_server_param_custom(name, value);
+
+    if (result == MavlinkParameterServer::Result::Success) {
+        return ParamServer::Result::Success;
+    } else {
+        return ParamServer::Result::NotFound;
+    }
+}
+
 ParamServer::AllParams ParamServerImpl::retrieve_all_params() const
 {
     auto tmp = _server_component_impl->mavlink_parameter_server().retrieve_all_server_params();

src/mavsdk/plugins/param_server/param_server_impl.h

@@ -18,14 +18,20 @@ class ParamServerImpl : public ServerPluginImplBase {
 
     ParamServer::Result provide_param_int(std::string name, int32_t value);
 
+    ParamServer::Result change_param_int(std::string name, int32_t value);
+
     std::pair<ParamServer::Result, float> retrieve_param_float(std::string name) const;
 
     ParamServer::Result provide_param_float(std::string name, float value);
 
+    ParamServer::Result change_param_float(std::string name, float value);
+
     std::pair<ParamServer::Result, std::string> retrieve_param_custom(std::string name) const;
 
     ParamServer::Result provide_param_custom(std::string name, const std::string& value);
 
+    ParamServer::Result change_param_custom(std::string name, const std::string& value);
+
     ParamServer::AllParams retrieve_all_params() const;
 
     static ParamServer::Result