sparql triple store and graph (nodes, mostly)

1 files changed, 65 insertions, 0 deletions

diff --git a/bsfs/graph/graph.py b/bsfs/graph/graph.py
new file mode 100644
index 0000000..06271f6
--- /dev/null
+++ b/bsfs/graph/graph.py
@@ -0,0 +1,65 @@
+"""
+
+Part of the BlackStar filesystem (bsfs) module.
+A copy of the license is provided with the project.
+Author: Matthias Baumgartner, 2022
+"""
+# imports
+import typing
+
+# bsfs imports
+from bsfs.schema import Schema
+from bsfs.triple_store import TripleStoreBase
+from bsfs.utils import URI, typename
+
+# inner-module imports
+from . import nodes
+
+# exports
+__all__: typing.Sequence[str] = (
+    'Graph',
+    )
+
+
+## code ##
+
+class Graph():
+    """
+    """
+    # link to the triple storage backend.
+    __backend: TripleStoreBase
+
+    # user uri.
+    __user: URI
+
+    def __init__(self, backend: TripleStoreBase, user: URI):
+        self.__backend = backend
+        self.__user = user
+
+    def __hash__(self) -> int:
+        return hash((type(self), self.__backend, self.__user))
+
+    def __eq__(self, other) -> bool:
+        return isinstance(other, type(self)) \
+           and self.__backend == other.__backend \
+           and self.__user == other.__user
+
+    def __repr__(self) -> str:
+        return f'{typename(self)}(backend={repr(self.__backend)}, user={self.__user})'
+
+    def __str__(self) -> str:
+        return f'{typename(self)}({str(self.__backend)}, {self.__user})'
+
+    @property
+    def schema(self) -> Schema:
+        """Return the store's local schema."""
+        return self.__backend.schema
+
+    def nodes(self, node_type: URI, guids: typing.Iterable[URI]) -> nodes.Nodes:
+        """
+        """
+        node_type = self.schema.node(node_type)
+        # NOTE: Nodes constructor materializes guids.
+        return nodes.Nodes(self.__backend, self.__user, node_type, guids)
+
+## EOF ##