feat(flow): add set remove and set_last

gnes/flow/__init__.py

@@ -33,6 +33,10 @@ class FlowTopologyError(ValueError):
     """Exception when the topology is ambiguous"""
 
 
+class FlowMissingNode(ValueError):
+    """Exception when the topology is ambiguous"""
+
+
 class FlowBuildLevelMismatch(ValueError):
     """Exception when required level is higher than the current build level"""
 
@@ -113,7 +117,7 @@ def __init__(self, with_frontend: bool = True, **kwargs):
         self._service_edges = {}
         self._service_name_counter = {k: 0 for k in Flow._service2parser.keys()}
         self._service_contexts = []
-        self._last_add_service = None
+        self._last_changed_service = []
         self._common_kwargs = kwargs
         self._frontend = None
         self._client = None
@@ -320,17 +324,153 @@ def add_router(self, *args, **kwargs) -> 'Flow':
         """Add a router to the current flow, a shortcut of :py:meth:`add(Service.Router)`"""
         return self.add(Service.Router, *args, **kwargs)
 
+    def set_last_service(self, name: str, copy_flow: bool = True) -> 'Flow':
+        """
+        Set a service as the last service in the flow, useful when modifying the flow.
+
+        :param name: the name of the existing service
+        :param copy_flow: when set to true, then always copy the current flow and do the modification on top of it then return, otherwise, do in-line modification
+        :return: a (new) flow object with modification
+        """
+        op_flow = copy.deepcopy(self) if copy_flow else self
+
+        if name not in op_flow._service_nodes:
+            raise FlowMissingNode('service_in: %s can not be found in this Flow' % name)
+
+        if op_flow._last_changed_service and name == op_flow._last_changed_service[-1]:
+            pass
+        else:
+            op_flow._last_changed_service.append(name)
+
+        # graph is now changed so we need to
+        # reset the build level to the lowest
+        op_flow._build_level = Flow.BuildLevel.EMPTY
+
+        return op_flow
+
+    def set(self, name: str, service_in: Union[str, Tuple[str], List[str], 'Service'] = None,
+            service_out: Union[str, Tuple[str], List[str], 'Service'] = None,
+            copy_flow: bool = True,
+            clear_old_attr: bool = False,
+            as_last_service: bool = False,
+            **kwargs) -> 'Flow':
+        """
+        Set the attribute of an existing service (added by :py:meth:`add`) in the flow.
+        For the attributes or kwargs that aren't given, they will remain unchanged as before.
+
+        :param name: the name of the existing service
+        :param service_in: the name of the service(s) that this service receives data from.
+                           One can also use 'Service.Frontend' to indicate the connection with the frontend.
+        :param service_out:  the name of the service(s) that this service sends data to.
+                           One can also use 'Service.Frontend' to indicate the connection with the frontend.
+        :param copy_flow: when set to true, then always copy the current flow and do the modification on top of it then return, otherwise, do in-line modification
+        :param clear_old_attr: remove old attribute value before setting the new one
+        :param as_last_service: whether setting the changed service as the last service in the graph
+        :param kwargs: other keyword-value arguments that the service CLI supports
+        :return: a (new) flow object with modification
+        """
+        op_flow = copy.deepcopy(self) if copy_flow else self
+
+        if name not in op_flow._service_nodes:
+            raise FlowMissingNode('service_in: %s can not be found in this Flow' % name)
+
+        node = op_flow._service_nodes[name]
+        service = node['service']
+
+        if service_in:
+            service_in = op_flow._parse_service_endpoints(op_flow, name, service_in, connect_to_last_service=True)
+
+            if clear_old_attr:
+                node['incomes'] = service_in
+                # remove all edges point to this service
+                for n in op_flow._service_nodes.values():
+                    if name in n['outgoings']:
+                        n['outgoings'].remove(name)
+            else:
+                node['incomes'] = node['incomes'].union(service_in)
+
+            # add it the new edge back
+            for s in service_in:
+                op_flow._service_nodes[s]['outgoings'].add(name)
+
+        if service_out:
+            service_out = op_flow._parse_service_endpoints(op_flow, name, service_out, connect_to_last_service=False)
+            node['outgoings'] = service_out
+            if clear_old_attr:
+                # remove all edges this service point to
+                for n in op_flow._service_nodes.values():
+                    if name in n['incomes']:
+                        n['incomes'].remove(name)
+            else:
+                node['outgoings'] = node['outgoings'].union(service_out)
+
+            for s in service_out:
+                op_flow._service_nodes[s]['incomes'].add(name)
+
+        if kwargs:
+            if not clear_old_attr:
+                node['kwargs'].update(kwargs)
+                kwargs = node['kwargs']
+            args, p_args = op_flow._get_parsed_args(op_flow, Flow._service2parser[service], kwargs)
+            node['args'] = args
+            node['parsed_args'] = p_args
+
+        if as_last_service:
+            op_flow.set_last_service(name, False)
+
+        # graph is now changed so we need to
+        # reset the build level to the lowest
+        op_flow._build_level = Flow.BuildLevel.EMPTY
+
+        return op_flow
+
+    def remove(self, name: str = None, copy_flow: bool = True) -> 'Flow':
+        """
+        Remove a service from the flow.
+
+        :param name: the name of the existing service
+        :param copy_flow: when set to true, then always copy the current flow and do the modification on top of it then return, otherwise, do in-line modification
+        :return: a (new) flow object with modification
+        """
+
+        op_flow = copy.deepcopy(self) if copy_flow else self
+
+        if name not in op_flow._service_nodes:
+            raise FlowMissingNode('service_in: %s can not be found in this Flow' % name)
+
+        op_flow._service_nodes.pop(name)
+
+        # remove all edges point to this service
+        for n in op_flow._service_nodes.values():
+            if name in n['outgoings']:
+                n['outgoings'].remove(name)
+            if name in n['incomes']:
+                n['incomes'].remove(name)
+
+        if op_flow._service_nodes:
+            op_flow._last_changed_service = [v for v in op_flow._last_changed_service if v != name]
+        else:
+            op_flow._last_changed_service = []
+
+        # graph is now changed so we need to
+        # reset the build level to the lowest
+        op_flow._build_level = Flow.BuildLevel.EMPTY
+
+        return op_flow
+
     def add(self, service: Union['Service', str],
             name: str = None,
             service_in: Union[str, Tuple[str], List[str], 'Service'] = None,
             service_out: Union[str, Tuple[str], List[str], 'Service'] = None,
             copy_flow: bool = True,
             **kwargs) -> 'Flow':
         """
-        Add a service to the current flow object and return the new modified flow object
+        Add a service to the current flow object and return the new modified flow object.
+        The attribute of the service can be later changed with :py:meth:`set` or deleted with :py:meth:`remove`
 
         :param service: a 'Service' enum or string, possible choices: Encoder, Router, Preprocessor, Indexer, Frontend
-        :param name: the name indentifier of the service, useful in 'service_in' and 'service_out'
+        :param name: the name identifier of the service, can be used in 'service_in',
+                    'service_out', :py:meth:`set` and :py:meth:`remove`.
         :param service_in: the name of the service(s) that this service receives data from.
                            One can also use 'Service.Frontend' to indicate the connection with the frontend.
         :param service_out:  the name of the service(s) that this service sends data to.
@@ -371,15 +511,16 @@ def add(self, service: Union['Service', str],
             'parsed_args': p_args,
             'args': args,
             'incomes': service_in,
-            'outgoings': service_out}
+            'outgoings': service_out,
+            'kwargs': kwargs}
 
         # direct all income services' output to the current service
         for s in service_in:
             op_flow._service_nodes[s]['outgoings'].add(name)
         for s in service_out:
             op_flow._service_nodes[s]['incomes'].add(name)
 
-        op_flow._last_add_service = name
+        op_flow.set_last_service(name, False)
 
         # graph is now changed so we need to
         # reset the build level to the lowest
@@ -395,16 +536,16 @@ def _parse_service_endpoints(op_flow, cur_service_name, service_endpoint, connec
         elif service_endpoint == Service.Frontend:
             service_endpoint = [op_flow._frontend]
         elif not service_endpoint:
-            if op_flow._last_add_service and connect_to_last_service:
-                service_endpoint = [op_flow._last_add_service]
+            if op_flow._last_changed_service and connect_to_last_service:
+                service_endpoint = [op_flow._last_changed_service[-1]]
             else:
                 service_endpoint = []
         if isinstance(service_endpoint, list) or isinstance(service_endpoint, tuple):
             for s in service_endpoint:
                 if s == cur_service_name:
                     raise FlowTopologyError('the income of a service can not be itself')
                 if s not in op_flow._service_nodes:
-                    raise FlowTopologyError('service_in: %s can not be found in this Flow' % s)
+                    raise FlowMissingNode('service_in: %s can not be found in this Flow' % s)
         else:
             raise ValueError('service_in=%s is not parsable' % service_endpoint)
         return set(service_endpoint)
@@ -444,11 +585,11 @@ def _build_graph(self, copy_flow: bool) -> 'Flow':
         if not op_flow._frontend:
             raise FlowImcompleteError('frontend does not exist, you may need to add_frontend()')
 
-        if not op_flow._last_add_service or not op_flow._service_nodes:
+        if not op_flow._last_changed_service or not op_flow._service_nodes:
             raise FlowTopologyError('flow is empty?')
 
         # close the loop
-        op_flow._service_nodes[op_flow._frontend]['incomes'].add(op_flow._last_add_service)
+        op_flow._service_nodes[op_flow._frontend]['incomes'].add(op_flow._last_changed_service[-1])
 
         # build all edges
         for k, v in op_flow._service_nodes.items():

tests/test_gnes_flow.py

@@ -176,3 +176,39 @@ def test_query_flow_plot(self):
                 .add(gfs.Router, name='scorer', yaml_path=os.path.join(self.dirname, 'yaml/flow-score.yml'))
                 .add(gfs.Indexer, name='doc_idx', yaml_path=os.path.join(self.dirname, 'yaml/flow-dictindex.yml')))
         print(flow.build(backend=None).to_url())
+
+    def test_flow_add_set(self):
+        f = (Flow(check_version=False, route_table=True)
+             .add(gfs.Preprocessor, name='prep', yaml_path='SentSplitPreprocessor', replicas=4)
+             .add(gfs.Encoder, yaml_path='PyTorchTransformers', replicas=3)
+             .add(gfs.Indexer, name='vec_idx', yaml_path='NumpyIndexer', replicas=2)
+             .add(gfs.Indexer, name='doc_idx', yaml_path='DictIndexer', service_in='prep', replicas=2)
+             .add(gfs.Router, name='sync_barrier', yaml_path='BaseReduceRouter',
+                  num_part=2, service_in=['vec_idx', 'doc_idx'])
+             .build(backend=None))
+
+        print(f.to_url())
+        print(f.set('prep', replicas=1).build(backend=None).to_url())
+        # make it as query flow
+
+        f1 = (f
+              .remove('sync_barrier')
+              .remove('doc_idx')
+              .set_last_service('vec_idx')
+              .add_router('scorer', yaml_path=os.path.join(self.dirname, 'yaml/flow-score.yml'))
+              .add_indexer('doc_idx', yaml_path='DictIndexer', replicas=2)
+              .build(backend=None))
+
+        print(f1.to_url())
+
+        # another way to convert f to an index flow
+
+        f2 = (f
+              .set_last_service('vec_idx')
+              .add_router('scorer', yaml_path=os.path.join(self.dirname, 'yaml/flow-score.yml'))
+              .set('doc_idx', service_in='scorer', yaml_path='DictIndexer', replicas=2, clear_old_attr=True)
+              .remove('sync_barrier')
+              .set_last_service('doc_idx')
+              .build(backend=None))
+
+        print(f2.to_url())