DirectedGraphAnalysis: Create new base class for graph analyses.

Also move typing imports into TYPE_CHECKING block.

Signed-off-by: Chris PeBenito <pebenito@ieee.org>

setools/dta.py

@@ -20,6 +20,7 @@ except ImportError:
 from .descriptors import EdgeAttrDict, EdgeAttrList
 from .mixins import NetworkXGraphEdge
 from .policyrep import AnyTERule, SELinuxPolicy, TERuletype, Type
+from .query import DirectedGraphAnalysis
 
 __all__ = ['DomainTransitionAnalysis', 'DomainTransition', 'DomainEntrypoint', 'DTAPath']
 
@@ -56,7 +57,7 @@ DTAPath = Iterable[DomainTransition]
 RuleHash = DefaultDict[Type, List[AnyTERule]]
 
 
-class DomainTransitionAnalysis:
+class DomainTransitionAnalysis(DirectedGraphAnalysis):
 
     """Domain transition analysis."""
 

setools/infoflow.py

@@ -18,13 +18,14 @@ from .descriptors import EdgeAttrIntMax, EdgeAttrList
 from .mixins import NetworkXGraphEdge
 from .permmap import PermissionMap
 from .policyrep import AVRule, SELinuxPolicy, TERuletype, Type
+from .query import DirectedGraphAnalysis
 
 __all__ = ['InfoFlowAnalysis']
 
 InfoFlowPath = Iterable['InfoFlowStep']
 
 
-class InfoFlowAnalysis:
+class InfoFlowAnalysis(DirectedGraphAnalysis):
 
     """Information flow analysis."""
 

setools/query.py

@@ -4,21 +4,24 @@
 # SPDX-License-Identifier: LGPL-2.1-only
 #
 from abc import ABC, abstractmethod
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
     from logging import Logger
     from typing import Iterable
-
+    from networkx import DiGraph
     from .policyrep import SELinuxPolicy
 
 
 class PolicyQuery(ABC):
 
-    """Abstract base class for SELinux policy queries."""
+    """Abstract base class for all SELinux policy analyses."""
 
-    log: Logger
-    policy: SELinuxPolicy
+    log: "Logger"
+    policy: "SELinuxPolicy"
 
-    def __init__(self, policy: SELinuxPolicy, **kwargs) -> None:
-        self.policy = policy
+    def __init__(self, policy: "SELinuxPolicy", **kwargs) -> None:
+        self.policy: "SELinuxPolicy" = policy
 
         # keys are sorted in reverse order so regex settings
         # are set before the criteria, e.g. name_regex
@@ -33,9 +36,16 @@ class PolicyQuery(ABC):
             setattr(self, name, kwargs[name])
 
     @abstractmethod
-    def results(self) -> Iterable:
+    def results(self) -> "Iterable":
         """
         Generator which returns the matches for the query.  This method
         should be overridden by subclasses.
         """
         pass
+
+
+class DirectedGraphAnalysis(PolicyQuery):
+
+    """Abstract base class for graph-basded SELinux policy analysis."""
+
+    G: "DiGraph"