new: fully support parameterized db object (#70)

* new: fully support parameterized `db` object

* fix: `hosts`

* fix: docstring

* new: support `use_gpu` algorithm parameter

* new: `test_multiple_graph_sessions`

Author: aMahanna

README.md

@@ -166,13 +166,16 @@ import nx_arangodb as nxadb
 
 G = nxadb.Graph(name="MyGraph")
 
+# Option 1: Use Global Config
 nx.config.backends.arangodb.use_gpu = False
-
 nx.pagerank(G)
 nx.betweenness_centrality(G)
 # ...
-
 nx.config.backends.arangodb.use_gpu = True
+
+# Option 2: Use Local Config
+nx.pagerank(G, use_gpu=False)
+nx.betweenness_centrality(G, use_gpu=False)
 ```
 
 <p align="center">

_nx_arangodb/__init__.py

@@ -74,15 +74,7 @@ def get_info():
     for key in info_keys:
         del d[key]
 
-    d["default_config"] = {
-        "host": None,
-        "username": None,
-        "password": None,
-        "db_name": None,
-        "read_parallelism": None,
-        "read_batch_size": None,
-        "use_gpu": True,
-    }
+    d["default_config"] = {"use_gpu": True}
 
     return d
 

doc/algorithms/index.rst

@@ -43,14 +43,17 @@ You can also force-run algorithms on CPU even if ``nx-cugraph`` is installed:
 
    G = nxadb.Graph(name="MyGraph")
 
+   # Option 1: Use Global Config
    nx.config.backends.arangodb.use_gpu = False
-
    nx.pagerank(G)
    nx.betweenness_centrality(G)
    # ...
-
    nx.config.backends.arangodb.use_gpu = True
 
+   # Option 2: Use Local Config
+   nx.pagerank(G, use_gpu=False)
+   nx.betweenness_centrality(G, use_gpu=False)
+
 
 .. image:: ../_static/dispatch.png
    :align: center

doc/nx_arangodb.ipynb

@@ -236,9 +236,7 @@
       "outputs": [],
       "source": [
         "# 5. Run an algorithm (CPU)\n",
-        "nx.config.backends.arangodb.use_gpu = False # Optional\n",
-        "\n",
-        "res = nx.pagerank(G)"
+        "res = nx.pagerank(G, use_gpu=False)"
       ]
     },
     {
@@ -357,8 +355,6 @@
       "source": [
         "# 4. Run an algorithm (GPU)\n",
         "# See *Package Installation* to install nx-cugraph ^\n",
-        "nx.config.backends.arangodb.use_gpu = True\n",
-        "\n",
         "res = nx.pagerank(G)"
       ]
     },

nx_arangodb/classes/dict/adj.py

@@ -105,6 +105,8 @@ def adjlist_outer_dict_factory(
     db: StandardDatabase,
     graph: Graph,
     default_node_type: str,
+    read_parallelism: int,
+    read_batch_size: int,
     edge_type_key: str,
     edge_type_func: Callable[[str, str], str],
     graph_type: str,
@@ -115,6 +117,8 @@ def adjlist_outer_dict_factory(
         db,
         graph,
         default_node_type,
+        read_parallelism,
+        read_batch_size,
         edge_type_key,
         edge_type_func,
         graph_type,
@@ -1454,6 +1458,12 @@ class AdjListOuterDict(UserDict[str, AdjListInnerDict]):
     symmetrize_edges_if_directed : bool
         Whether to add the reverse edge if the graph is directed.
 
+    read_parallelism : int
+        The number of parallel threads to use for reading data in _fetch_all.
+
+    read_batch_size : int
+        The number of documents to read in each batch in _fetch_all.
+
     Example
     -------
     >>> g = nxadb.Graph(name="MyGraph")
@@ -1467,6 +1477,8 @@ def __init__(
         db: StandardDatabase,
         graph: Graph,
         default_node_type: str,
+        read_parallelism: int,
+        read_batch_size: int,
         edge_type_key: str,
         edge_type_func: Callable[[str, str], str],
         graph_type: str,
@@ -1489,6 +1501,8 @@ def __init__(
         self.edge_type_key = edge_type_key
         self.edge_type_func = edge_type_func
         self.default_node_type = default_node_type
+        self.read_parallelism = read_parallelism
+        self.read_batch_size = read_batch_size
         self.adjlist_inner_dict_factory = adjlist_inner_dict_factory(
             db,
             graph,
@@ -1853,6 +1867,8 @@ def _fetch_all(self) -> None:
             is_directed=True,
             is_multigraph=self.is_multigraph,
             symmetrize_edges_if_directed=self.symmetrize_edges_if_directed,
+            read_parallelism=self.read_parallelism,
+            read_batch_size=self.read_batch_size,
         )
 
         # Even if the Graph is undirected,

nx_arangodb/classes/dict/node.py

@@ -40,10 +40,20 @@
 
 
 def node_dict_factory(
-    db: StandardDatabase, graph: Graph, default_node_type: str
+    db: StandardDatabase,
+    graph: Graph,
+    default_node_type: str,
+    read_parallelism: int,
+    read_batch_size: int,
 ) -> Callable[..., NodeDict]:
     """Factory function for creating a NodeDict."""
-    return lambda: NodeDict(db, graph, default_node_type)
+    return lambda: NodeDict(
+        db,
+        graph,
+        default_node_type,
+        read_parallelism,
+        read_batch_size,
+    )
 
 
 def node_attr_dict_factory(
@@ -250,6 +260,12 @@ class NodeDict(UserDict[str, NodeAttrDict]):
     default_node_type : str
         The default node type for the graph.
 
+    read_parallelism : int
+        The number of parallel threads to use for reading data in _fetch_all.
+
+    read_batch_size : int
+        The number of documents to read in each batch in _fetch_all.
+
     Example
     -------
     >>> G = nxadb.Graph("MyGraph")
@@ -262,6 +278,8 @@ def __init__(
         db: StandardDatabase,
         graph: Graph,
         default_node_type: str,
+        read_parallelism: int,
+        read_batch_size: int,
         *args: Any,
         **kwargs: Any,
     ):
@@ -271,6 +289,9 @@ def __init__(
         self.db = db
         self.graph = graph
         self.default_node_type = default_node_type
+        self.read_parallelism = read_parallelism
+        self.read_batch_size = read_batch_size
+
         self.node_attr_dict_factory = node_attr_dict_factory(self.db, self.graph)
 
         self.FETCHED_ALL_DATA = False
@@ -472,6 +493,8 @@ def _fetch_all(self):
             is_directed=False,  # not used
             is_multigraph=False,  # not used
             symmetrize_edges_if_directed=False,  # not used
+            read_parallelism=self.read_parallelism,
+            read_batch_size=self.read_batch_size,
         )
 
         for node_id, node_data in node_dict.items():

nx_arangodb/classes/function.py

@@ -47,6 +47,8 @@ def get_arangodb_graph(
     is_directed: bool,
     is_multigraph: bool,
     symmetrize_edges_if_directed: bool,
+    read_parallelism: int,
+    read_batch_size: int,
 ) -> Tuple[
     NodeDict,
     GraphAdjDict | DiGraphAdjDict | MultiGraphAdjDict | MultiDiGraphAdjDict,
@@ -142,11 +144,10 @@ def get_arangodb_graph(
     if not load_adj_dict and not load_coo:
         metagraph["edgeCollections"] = {}
 
-    config = nx.config.backends.arangodb
-    assert config.db_name
-    assert config.host
-    assert config.username
-    assert config.password
+    hosts = adb_graph._conn._hosts
+    hosts = hosts.split(",") if type(hosts) is str else hosts
+    db_name = adb_graph._conn._db_name
+    username, password = adb_graph._conn._auth
 
     (
         node_dict,
@@ -157,20 +158,20 @@ def get_arangodb_graph(
         vertex_ids_to_index,
         edge_values,
     ) = NetworkXLoader.load_into_networkx(
-        config.db_name,
+        database=db_name,
         metagraph=metagraph,
-        hosts=[config.host],
-        username=config.username,
-        password=config.password,
+        hosts=hosts,
+        username=username,
+        password=password,
         load_adj_dict=load_adj_dict,
         load_coo=load_coo,
         load_all_vertex_attributes=load_all_vertex_attributes,
         load_all_edge_attributes=load_all_edge_attributes,
         is_directed=is_directed,
         is_multigraph=is_multigraph,
         symmetrize_edges_if_directed=symmetrize_edges_if_directed,
-        parallelism=config.read_parallelism,
-        batch_size=config.read_batch_size,
+        parallelism=read_parallelism,
+        batch_size=read_batch_size,
     )
 
     return (

nx_arangodb/classes/graph.py

@@ -214,11 +214,13 @@ def __init__(
         self.use_nxcg_cache = True
         self.nxcg_graph = None
 
+        self.edge_type_key = edge_type_key
+        self.read_parallelism = read_parallelism
+        self.read_batch_size = read_batch_size
+
         # Does not apply to undirected graphs
         self.symmetrize_edges = symmetrize_edges
 
-        self.edge_type_key = edge_type_key
-
         # TODO: Consider this
         # if not self.__graph_name:
         #     if incoming_graph_data is not None:
@@ -227,8 +229,8 @@ def __init__(
 
         self._loaded_incoming_graph_data = False
         if self.graph_exists_in_db:
-            self._set_factory_methods()
-            self.__set_arangodb_backend_config(read_parallelism, read_batch_size)
+            self._set_factory_methods(read_parallelism, read_batch_size)
+            self.__set_arangodb_backend_config()
 
             if overwrite_graph:
                 logger.info("Overwriting graph...")
@@ -284,7 +286,7 @@ def __init__(
     # Init helper methods #
     #######################
 
-    def _set_factory_methods(self) -> None:
+    def _set_factory_methods(self, read_parallelism: int, read_batch_size: int) -> None:
         """Set the factory methods for the graph, _node, and _adj dictionaries.
 
         The ArangoDB CRUD operations are handled by the modified dictionaries.
@@ -299,39 +301,29 @@ def _set_factory_methods(self) -> None:
         """
 
         base_args = (self.db, self.adb_graph)
+
         node_args = (*base_args, self.default_node_type)
-        adj_args = (
-            *node_args,
-            self.edge_type_key,
-            self.edge_type_func,
-            self.__class__.__name__,
+        node_args_with_read = (*node_args, read_parallelism, read_batch_size)
+
+        adj_args = (self.edge_type_key, self.edge_type_func, self.__class__.__name__)
+        adj_inner_args = (*node_args, *adj_args)
+        adj_outer_args = (
+            *node_args_with_read,
+            *adj_args,
+            self.symmetrize_edges,
         )
 
         self.graph_attr_dict_factory = graph_dict_factory(*base_args)
 
-        self.node_dict_factory = node_dict_factory(*node_args)
+        self.node_dict_factory = node_dict_factory(*node_args_with_read)
         self.node_attr_dict_factory = node_attr_dict_factory(*base_args)
 
         self.edge_attr_dict_factory = edge_attr_dict_factory(*base_args)
-        self.adjlist_inner_dict_factory = adjlist_inner_dict_factory(*adj_args)
-        self.adjlist_outer_dict_factory = adjlist_outer_dict_factory(
-            *adj_args, self.symmetrize_edges
-        )
-
-    def __set_arangodb_backend_config(
-        self, read_parallelism: int, read_batch_size: int
-    ) -> None:
-        if not all([self._host, self._username, self._password, self._db_name]):
-            m = "Must set all environment variables to use the ArangoDB Backend with an existing graph"  # noqa: E501
-            raise OSError(m)
+        self.adjlist_inner_dict_factory = adjlist_inner_dict_factory(*adj_inner_args)
+        self.adjlist_outer_dict_factory = adjlist_outer_dict_factory(*adj_outer_args)
 
+    def __set_arangodb_backend_config(self) -> None:
         config = nx.config.backends.arangodb
-        config.host = self._host
-        config.username = self._username
-        config.password = self._password
-        config.db_name = self._db_name
-        config.read_parallelism = read_parallelism
-        config.read_batch_size = read_batch_size
         config.use_gpu = True  # Only used by default if nx-cugraph is available
 
     def __set_edge_collections_attributes(self, attributes: set[str] | None) -> None:
@@ -345,7 +337,7 @@ def __set_edge_collections_attributes(self, attributes: set[str] | None) -> None
             self._edge_collections_attributes.add("_id")
 
     def __set_db(self, db: Any = None) -> None:
-        self._host = os.getenv("DATABASE_HOST")
+        self._hosts = os.getenv("DATABASE_HOST", "").split(",")
         self._username = os.getenv("DATABASE_USERNAME")
         self._password = os.getenv("DATABASE_PASSWORD")
         self._db_name = os.getenv("DATABASE_NAME")
@@ -355,17 +347,20 @@ def __set_db(self, db: Any = None) -> None:
                 m = "arango.database.StandardDatabase"
                 raise TypeError(m)
 
-            db.version()
+            db.version()  # make sure the connection is valid
             self.__db = db
+            self._db_name = db.name
+            self._hosts = db._conn._hosts
+            self._username, self._password = db._conn._auth
             return
 
-        if not all([self._host, self._username, self._password, self._db_name]):
+        if not all([self._hosts, self._username, self._password, self._db_name]):
             m = "Database environment variables not set. Can't connect to the database"
             logger.warning(m)
             self.__db = None
             return
 
-        self.__db = ArangoClient(hosts=self._host, request_timeout=None).db(
+        self.__db = ArangoClient(hosts=self._hosts, request_timeout=None).db(
             self._db_name, self._username, self._password, verify=True
         )
 

nx_arangodb/classes/multigraph.py

@@ -229,8 +229,8 @@ def __init__(
     # Init helper methods #
     #######################
 
-    def _set_factory_methods(self) -> None:
-        super()._set_factory_methods()
+    def _set_factory_methods(self, read_parallelism: int, read_batch_size: int) -> None:
+        super()._set_factory_methods(read_parallelism, read_batch_size)
         self.edge_key_dict_factory = edge_key_dict_factory(
             self.db,
             self.adb_graph,