Porting rosapi package. (#388)

Porting rosapi package.

Signed-off-by: Juan Ignacio Ubeira <jubeira@ekumenlabs.com>

rosapi/package.xml

@@ -22,7 +22,13 @@
   <buildtool_depend>rosidl_default_generators</buildtool_depend>
 
   <exec_depend>rclpy</exec_depend>
+  <exec_depend>rcl_interfaces</exec_depend>
   <exec_depend>rosbridge_library</exec_depend>
+  <exec_depend>ros2node</exec_depend>
+  <exec_depend>ros2param</exec_depend>
+  <exec_depend>ros2pkg</exec_depend>
+  <exec_depend>ros2service</exec_depend>
+  <exec_depend>ros2topic</exec_depend>
   <!--
   <exec_depend>rosnode</exec_depend>
   <exec_depend>rosgraph</exec_depend>

rosapi/src/rosapi/glob_helper.py

@@ -1,36 +1,36 @@
 #!/usr/bin/env python
 
-import rospy
+from collections import namedtuple
 import fnmatch
+from rcl_interfaces.msg import ParameterType
 
-topics_glob = []
-services_glob = []
-params_glob = []
+Globs = namedtuple('Globs', ['topics', 'services', 'params'])
 
 
-def get_globs():
+def get_globs(node):
 
-    global topics_glob
-    global services_glob
-    global params_glob
-
-    def get_param(param_name):
-        param = rospy.get_param(param_name, '')
+    def get_param(parameter_name):
+        parameter_value = node.get_parameter(parameter_name).get_parameter_value()
+        if parameter_value.type == ParameterType.PARAMETER_STRING:
+            parameter_value = parameter_value.string_value
+        else:
+            parameter_value = ''
         # strips array delimiters in case of an array style value
         return [
             element.strip().strip("'")
-            for element in param.strip('[').strip(']').split(',')
+            for element in parameter_value.strip('[').strip(']').split(',')
             if len(element.strip().strip("'")) > 0]
 
-    topics_glob = get_param('~topics_glob')
-    services_glob = get_param('~services_glob')
-    params_glob = get_param('~params_glob')
+    topics_glob = get_param('/topics_glob')
+    services_glob = get_param('/services_glob')
+    params_glob = get_param('/params_glob')
+    return Globs(topics_glob, services_glob, params_glob)
 
 
 def filter_globs(globs, full_list):
     # If the globs are empty (weren't defined in the params), return the full list
     if globs is not None and len(globs) > 0:
-        return filter(lambda x: any_match(x, globs), full_list)
+        return list(filter(lambda x: any_match(x, globs), full_list))
     else:
         return full_list
 

rosapi/src/rosapi/objectutils.py

@@ -95,7 +95,7 @@ def get_service_response_typedef_recursive(servicetype):
 
 def _get_typedef(instance):
     """ Gets a typedef dict for the specified instance """
-    if instance is None or not hasattr(instance, "__slots__") or not hasattr(instance, "_slot_types"):
+    if instance is None or not hasattr(instance, "__slots__") or not hasattr(instance, "_fields_and_field_types"):
         return None
 
     fieldnames = []
@@ -108,7 +108,7 @@ def _get_typedef(instance):
         fieldnames.append(name)
 
         # Pull out the type and determine whether it's an array
-        field_type = instance._slot_types[i]
+        field_type = instance._fields_and_field_types[name[1:]]  # Remove trailing underscore.
         arraylen = -1
         if field_type[-1:]==']':
             if field_type[-2:-1]=='[':

rosapi/src/rosapi/params.py

@@ -31,19 +31,40 @@
 # POSSIBILITY OF SUCH DAMAGE.
 
 import fnmatch
-import rospy
-import threading
-
 from json import loads, dumps
+import threading
 
+from rcl_interfaces.msg import Parameter, ParameterType, ParameterValue
+from rcl_interfaces.srv import ListParameters
+import rclpy
+from ros2node.api import get_absolute_node_name
+from ros2param.api import call_get_parameters, call_set_parameters, get_parameter_value
 
 """ Methods to interact with the param server.  Values have to be passed
 as JSON in order to facilitate dynamically typed SRV messages """
 
-# rospy parameter server isn't thread-safe
+# Ensure thread safety for setting / getting parameters.
 param_server_lock = threading.RLock()
+_node = None
+
+_parameter_type_mapping = ['', 'bool_value', 'integer_value', 'double_value', 'string_value', 'byte_array_value'
+                           'bool_array_value', 'integer_array_value', 'double_array_value', 'string_array_value']
+
+
+def init():
+    """
+    Initializes params module with a rclpy.node.Node for further use.
+    This function has to be called before any other for the module to work.
+    """
+    global _node
+    # TODO(@jubeira): remove this node; use rosapi node with MultiThreadedExecutor or
+    # async / await to prevent the service calls from blocking.
+    _node = rclpy.create_node('rosapi_params')
+
+
+def set_param(node_name, name, value, params_glob):
+    """ Sets a parameter in a given node """
 
-def set_param(name, value, params_glob):
     if params_glob and not any(fnmatch.fnmatch(str(name), glob) for glob in params_glob):
         # If the glob list is not empty and there are no glob matches,
         # stop the attempt to set the parameter.
@@ -55,48 +76,139 @@ def set_param(name, value, params_glob):
         d = loads(value)
     except ValueError:
         raise Exception("Due to the type flexibility of the ROS parameter server, the value argument to set_param must be a JSON-formatted string.")
+
+    node_name = get_absolute_node_name(node_name)
     with param_server_lock:
-        rospy.set_param(name, d)
-
-
-def get_param(name, default, params_glob):
+        _set_param(node_name, name, value)
+
+
+def _set_param(node_name, name, value, parameter_type=None):
+    """
+    Internal helper function for set_param.
+    Attempts to set the given parameter in the target node with the desired value,
+    deducing the parameter type if it's not specified.
+    parameter_type allows forcing a type for the given value; this is useful to delete parameters.
+    """
+    parameter = Parameter()
+    parameter.name = name
+    if parameter_type is None:
+        parameter.value = get_parameter_value(string_value=value)
+    else:
+        parameter.value = ParameterValue()
+        parameter.value.type = parameter_type
+        if parameter_type != ParameterType.PARAMETER_NOT_SET:
+            setattr(parameter.value, _parameter_type_mapping[parameter_type])
+
+    try:
+        # call_get_parameters will fail if node does not exist.
+        call_set_parameters(node=_node, node_name=node_name, parameters=[parameter])
+    except:
+        pass
+
+
+def get_param(node_name, name, default, params_glob):
+    """ Gets a parameter from a given node """
+
     if params_glob and not any(fnmatch.fnmatch(str(name), glob) for glob in params_glob):
         # If the glob list is not empty and there are no glob matches,
         # stop the attempt to get the parameter.
         return
     # If the glob list is empty (i.e. false) or the parameter matches
     # one of the glob strings, continue to get the parameter.
-    d = None
     if default is not "":
         try:
-            d = loads(default)
+            default = loads(default)
         except ValueError:
-            d = default
+            pass  # Keep default without modifications.
+
+    node_name = get_absolute_node_name(node_name)
     with param_server_lock:
-        value = rospy.get_param(name, d)
+        try:
+            # call_get_parameters will fail if node does not exist.
+            response = call_get_parameters(
+                node=_node, node_name=node_name,
+                parameter_names=[name])
+            pvalue = response.values[0]
+            # if type is 0 (parameter not set), the next line will raise an exception
+            # and return value shall go to default.
+            value = getattr(pvalue, _parameter_type_mapping[pvalue.type])
+        except:
+            # If either the node or the parameter does not exist, return default.
+            value = default
+
     return dumps(value)
 
-def has_param(name, params_glob):
+
+def has_param(node_name, name, params_glob):
+    """ Checks whether a given node has a parameter or not """
+
     if params_glob and not any(fnmatch.fnmatch(str(name), glob) for glob in params_glob):
         # If the glob list is not empty and there are no glob matches,
         # stop the attempt to set the parameter.
         return False
     # If the glob list is empty (i.e. false) or the parameter matches
     # one of the glob strings, check whether the parameter exists.
+    node_name = get_absolute_node_name(node_name)
     with param_server_lock:
-        return rospy.has_param(name)
+        try:
+            response = call_get_parameters(
+                node=_node, node_name=node_name,
+                parameter_names=[name])
+        except:
+            return False
+
+    return response.values[0].type > 0 and response.values[0].type < len(_parameter_type_mapping)
+
+
+def delete_param(node_name, name, params_glob):
+    """ Deletes a parameter in a given node """
 
-def delete_param(name, params_glob):
     if params_glob and not any(fnmatch.fnmatch(str(name), glob) for glob in params_glob):
         # If the glob list is not empty and there are no glob matches,
         # stop the attempt to delete the parameter.
         return
     # If the glob list is empty (i.e. false) or the parameter matches
     # one of the glob strings, continue to delete the parameter.
-    if has_param(name, params_glob):
+    node_name = get_absolute_node_name(node_name)
+    if has_param(node_name, name, params_glob):
         with param_server_lock:
-            rospy.delete_param(name)
+            _set_param(node_name, name, None, ParameterType.PARAMETER_NOT_SET)
+
+
+def get_param_names(node_name, params_glob):
+    """ Gets list of parameter names for a given node """
+
+    node_name = get_absolute_node_name(node_name)
+
+    with param_server_lock:
+        if params_glob:
+            # If there is a parameter glob, filter by it.
+            return list(filter(
+                lambda x: any(fnmatch.fnmatch(str(x), glob) for glob in params_glob),
+                _get_param_names(node_name)))
+        else:
+            # If there is no parameter glob, don't filter.
+            return _get_param_names(node_name)
+
 
+def _get_param_names(node_name):
+    client = _node.create_client(ListParameters, '{}/list_parameters'.format(node_name))
+
+    ready = client.wait_for_service(timeout_sec=5.0)
+    if not ready:
+        raise RuntimeError('Wait for list_parameters service timed out')
+
+    request = ListParameters.Request()
+    future = client.call_async(request)
+    rclpy.spin_until_future_complete(_node, future)
+    response = future.result()
+    if response is not None:
+        return response.result.names
+    else:
+        return []
+
+
+# TODO(@jubeira): functions to be ported below.
 def search_param(name, params_glob):
     if params_glob and not any(fnmatch.fnmatch(str(name), glob) for glob in params_glob):
         # If the glob list is not empty and there are no glob matches,
@@ -105,13 +217,3 @@ def search_param(name, params_glob):
     # If the glob list is empty (i.e. false) or the parameter matches
     # one of the glob strings, continue to find the parameter.
     return rospy.search_param(name)
-
-def get_param_names(params_glob):
-    with param_server_lock:
-        if params_glob:
-            # If there is a parameter glob, filter by it.
-            return filter(lambda x: any(fnmatch.fnmatch(str(x), glob) for glob in params_glob), rospy.get_param_names())
-        else:
-            # If there is no parameter glob, don't filter.
-            return rospy.get_param_names()
-