Implement context pointer for Graph

Author: jcmosc

Sources/ComputeCxx/Graph/AGGraph.cpp

@@ -79,6 +79,18 @@ AGGraphRef AGGraphContextGetGraph(AGUnownedGraphContextRef storage) {
     return graph_context->to_cf();
 }
 
+#pragma mark - User context
+
+const void *AGGraphGetContext(AGGraphRef graph) {
+    auto graph_context = AG::Graph::Context::from_cf(graph);
+    return graph_context->context();
+}
+
+void AGGraphSetContext(AGGraphRef graph, const void *context) {
+    auto graph_context = AG::Graph::Context::from_cf(graph);
+    graph_context->set_context(context);
+}
+
 #pragma mark - Attribute types
 
 uint32_t AGGraphInternAttributeType(AGUnownedGraphRef unowned_graph, AGTypeID type,

Sources/ComputeCxx/Graph/AGGraph.h

@@ -18,7 +18,7 @@ typedef struct AGGraphContextStorage *AGUnownedGraphContextRef AG_SWIFT_STRUCT;
 
 CF_EXPORT
 CF_REFINED_FOR_SWIFT
-CFTypeID AGGraphGetTypeID() AG_SWIFT_NAME(getter : AGGraphRef.typeID());
+CFTypeID AGGraphGetTypeID() CF_SWIFT_NAME(getter:AGGraphRef.typeID());
 
 // MARK: Graph Context
 
@@ -39,6 +39,17 @@ CF_REFINED_FOR_SWIFT
 AGGraphRef AGGraphContextGetGraph(AGUnownedGraphContextRef context)
     CF_SWIFT_NAME(getter:AGUnownedGraphContextRef.graph(self:));
 
+// MARK: User context
+
+CF_EXPORT
+CF_REFINED_FOR_SWIFT
+const void *_Nullable AGGraphGetContext(AGGraphRef graph) CF_SWIFT_NAME(getter:AGGraphRef.context(self:));
+
+CF_EXPORT
+CF_REFINED_FOR_SWIFT
+void AGGraphSetContext(AGGraphRef graph, const void *_Nullable context)
+    CF_SWIFT_NAME(setter:AGGraphRef.context(self:_:));
+
 // MARK: Attribute types
 
 CF_EXPORT

Sources/ComputeCxx/Graph/Context.cpp

@@ -7,11 +7,7 @@
 
 namespace AG {
 
-Graph::Context::Context(Graph *graph) {
-    _graph = graph;
-    _context_info = nullptr;
-    _unique_id = AGMakeUniqueID();
-
+Graph::Context::Context(Graph *graph) : _graph(graph), _unique_id(AGMakeUniqueID()) {
     Graph::retain(graph);
     graph->_contexts_by_id.insert(_unique_id, this);
 }

Sources/ComputeCxx/Graph/Context.h

@@ -14,7 +14,7 @@ namespace AG {
 class Graph::Context {
   private:
     Graph *_graph;
-    const void *_context_info;
+    const void *_context = nullptr;
     uint64_t _unique_id;
 
     bool _invalidated;
@@ -28,6 +28,9 @@ class Graph::Context {
 
     Graph &graph() const { return *_graph; };
 
+    const void *_Nullable context() const { return _context; };
+    void set_context(const void *_Nullable context) { _context = context; };
+
     bool invalidated() const { return _invalidated; };
     void set_invalidated(bool invalidated) { _invalidated = invalidated; };
 };

Tests/ComputeTests/Shared/Graph/GraphTests.swift

@@ -20,6 +20,22 @@ struct GraphTests {
         }
 
     }
+    
+    @Suite
+    struct ContextTests {
+        
+        @Test
+        func storesContextPointer() {
+            let graph = Graph()
+            #expect(graph.context == nil)
+            
+            withUnsafePointer(to: "Value") { pointer in
+                graph.context = UnsafeRawPointer(pointer)
+                #expect(graph.context == UnsafeRawPointer(pointer))
+            }
+        }
+        
+    }
 
     @Suite
     struct InternAttributeTypeTests {