Make lifecycle impl get_current_state() const. (#2031)

clalancette · web-flow · commit 2d32d03ba3fc · 2022-10-24T17:14:12.000-04:00
We should only need to update the current state when it changes,
so we do that in the change_state method (which is not const).
Then we can just return the current_state_ object in
get_current_state, and then mark it as const.

Signed-off-by: Chris Lalancette &lt;clalancette@openrobotics.org&gt;
diff --git a/rclcpp_lifecycle/include/rclcpp_lifecycle/lifecycle_node.hpp b/rclcpp_lifecycle/include/rclcpp_lifecycle/lifecycle_node.hpp
@@ -839,7 +839,7 @@ class LifecycleNode : public node_interfaces::LifecycleNodeInterface,
    */
   RCLCPP_LIFECYCLE_PUBLIC
   const State &
-  get_current_state();
+  get_current_state() const;
 
   /// Return a list with the available states.
   /**
diff --git a/rclcpp_lifecycle/src/lifecycle_node.cpp b/rclcpp_lifecycle/src/lifecycle_node.cpp
@@ -535,7 +535,7 @@ LifecycleNode::register_on_error(
 }
 
 const State &
-LifecycleNode::get_current_state()
+LifecycleNode::get_current_state() const
 {
   return impl_->get_current_state();
 }
diff --git a/rclcpp_lifecycle/src/lifecycle_node_interface_impl.cpp b/rclcpp_lifecycle/src/lifecycle_node_interface_impl.cpp
@@ -182,6 +182,8 @@ LifecycleNode::LifecycleNodeInterfaceImpl::init(bool enable_communication_interf
         nullptr);
     }
   }
+
+  current_state_ = State(state_machine_.current_state);
 }
 
 bool
@@ -327,9 +329,8 @@ LifecycleNode::LifecycleNodeInterfaceImpl::on_get_transition_graph(
 }
 
 const State &
-LifecycleNode::LifecycleNodeInterfaceImpl::get_current_state()
+LifecycleNode::LifecycleNodeInterfaceImpl::get_current_state() const
 {
-  current_state_ = State(state_machine_.current_state);
   return current_state_;
 }
 
@@ -396,6 +397,9 @@ LifecycleNode::LifecycleNodeInterfaceImpl::change_state(
     return RCL_RET_ERROR;
   }
 
+  // Update the internal current_state_
+  current_state_ = State(state_machine_.current_state);
+
   auto get_label_for_return_code =
     [](node_interfaces::LifecycleNodeInterface::CallbackReturn cb_return_code) -> const char *{
       auto cb_id = static_cast<uint8_t>(cb_return_code);
@@ -421,6 +425,9 @@ LifecycleNode::LifecycleNodeInterfaceImpl::change_state(
     return RCL_RET_ERROR;
   }
 
+  // Update the internal current_state_
+  current_state_ = State(state_machine_.current_state);
+
   // error handling ?!
   // TODO(karsten1987): iterate over possible ret value
   if (cb_return_code == node_interfaces::LifecycleNodeInterface::CallbackReturn::ERROR) {
@@ -437,6 +444,10 @@ LifecycleNode::LifecycleNodeInterfaceImpl::change_state(
       return RCL_RET_ERROR;
     }
   }
+
+  // Update the internal current_state_
+  current_state_ = State(state_machine_.current_state);
+
   // This true holds in both cases where the actual callback
   // was successful or not, since at this point we have a valid transistion
   // to either a new primary state or error state
diff --git a/rclcpp_lifecycle/src/lifecycle_node_interface_impl.hpp b/rclcpp_lifecycle/src/lifecycle_node_interface_impl.hpp
@@ -65,7 +65,7 @@ class LifecycleNode::LifecycleNodeInterfaceImpl final
     std::function<node_interfaces::LifecycleNodeInterface::CallbackReturn(const State &)> & cb);
 
   const State &
-  get_current_state();
+  get_current_state() const;
 
   std::vector<State>
   get_available_states() const;

Original file line number	Diff line number	Diff line change
`@@ -535,7 +535,7 @@ LifecycleNode::register_on_error(`
`535`	`535`	`}`
`536`	`536`
`537`	`537`	`const State &`
`538`		`-LifecycleNode::get_current_state()`
	`538`	`+LifecycleNode::get_current_state() const`
`539`	`539`	`{`
`540`	`540`	`return impl_->get_current_state();`
`541`	`541`	`}`
Original file line number	Diff line number	Diff line change
`@@ -182,6 +182,8 @@ LifecycleNode::LifecycleNodeInterfaceImpl::init(bool enable_communication_interf`
`182`	`182`	`nullptr);`
`183`	`183`	`}`
`184`	`184`	`}`
	`185`	`+`
	`186`	`+ current_state_ = State(state_machine_.current_state);`
`185`	`187`	`}`
`186`	`188`
`187`	`189`	`bool`
`@@ -327,9 +329,8 @@ LifecycleNode::LifecycleNodeInterfaceImpl::on_get_transition_graph(`
`327`	`329`	`}`
`328`	`330`
`329`	`331`	`const State &`
`330`		`-LifecycleNode::LifecycleNodeInterfaceImpl::get_current_state()`
	`332`	`+LifecycleNode::LifecycleNodeInterfaceImpl::get_current_state() const`
`331`	`333`	`{`
`332`		`- current_state_ = State(state_machine_.current_state);`
`333`	`334`	`return current_state_;`
`334`	`335`	`}`
`335`	`336`
`@@ -396,6 +397,9 @@ LifecycleNode::LifecycleNodeInterfaceImpl::change_state(`
`396`	`397`	`return RCL_RET_ERROR;`
`397`	`398`	`}`
`398`	`399`
	`400`	`+ // Update the internal current_state_`
	`401`	`+ current_state_ = State(state_machine_.current_state);`
	`402`	`+`
`399`	`403`	`auto get_label_for_return_code =`
`400`	`404`	`[](node_interfaces::LifecycleNodeInterface::CallbackReturn cb_return_code) -> const char *{`
`401`	`405`	`auto cb_id = static_cast<uint8_t>(cb_return_code);`
`@@ -421,6 +425,9 @@ LifecycleNode::LifecycleNodeInterfaceImpl::change_state(`
`421`	`425`	`return RCL_RET_ERROR;`
`422`	`426`	`}`
`423`	`427`
	`428`	`+ // Update the internal current_state_`
	`429`	`+ current_state_ = State(state_machine_.current_state);`
	`430`	`+`
`424`	`431`	`// error handling ?!`
`425`	`432`	`// TODO(karsten1987): iterate over possible ret value`
`426`	`433`	`if (cb_return_code == node_interfaces::LifecycleNodeInterface::CallbackReturn::ERROR) {`
`@@ -437,6 +444,10 @@ LifecycleNode::LifecycleNodeInterfaceImpl::change_state(`
`437`	`444`	`return RCL_RET_ERROR;`
`438`	`445`	`}`
`439`	`446`	`}`
	`447`	`+`
	`448`	`+ // Update the internal current_state_`
	`449`	`+ current_state_ = State(state_machine_.current_state);`
	`450`	`+`
`440`	`451`	`// This true holds in both cases where the actual callback`
`441`	`452`	`// was successful or not, since at this point we have a valid transistion`
`442`	`453`	`// to either a new primary state or error state`