Dependencies

- Added TDB::gc code to remove dangling dependencies.

src/TDB.cpp

@@ -569,6 +569,7 @@ int TDB::commit ()
 // Scans the pending tasks for any that are completed or deleted, and if so,
 // moves them to the completed.data file.  Returns a count of tasks moved.
 // Now reverts expired waiting tasks to pending.
+// Now cleans up dangling dependencies.
 int TDB::gc ()
 {
   Timer t ("TDB::gc");
@@ -589,6 +590,27 @@ int TDB::gc ()
   std::vector <Task> ignore;
   loadPending (ignore, filter);
 
+  // Search for dangling dependencies.  These are dependencies whose uuid cannot
+  // be converted to an id by TDB.
+  std::vector <std::string> deps;
+  foreach (task, mPending)
+  {
+    if (task->has ("depends"))
+    {
+      deps.clear ();
+      task->getDependencies (deps);
+      foreach (dep, deps)
+        if (id (*dep) == 0)
+        {
+          task->removeDependency (*dep);
+          context.debug ("GC: Removed dangling dependency "
+                          + *dep
+                          + " from "
+                          + task->get ("uuid"));
+        }
+    }
+  }
+
   // Now move completed and deleted tasks from the pending list to the
   // completed list.  Isn't garbage collection easy?
   std::vector <Task> still_pending;

src/Task.cpp

@@ -495,16 +495,8 @@ void Task::addDependency (int id)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-void Task::removeDependency (int id)
+void Task::removeDependency (const std::string& uuid)
 {
-  std::string uuid = context.tdb.uuid (id);
-  if (uuid == "")
-  {
-    std::stringstream s;
-    s << "Could not find a UUID for id " << id << ".";
-    throw s.str ();
-  }
-
   std::vector <std::string> deps;
   split (deps, get ("depends"), ',');
 
@@ -519,6 +511,20 @@ void Task::removeDependency (int id)
   }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+void Task::removeDependency (int id)
+{
+  std::string uuid = context.tdb.uuid (id);
+  if (uuid != "")
+    removeDependency (uuid);
+  else
+  {
+    std::stringstream s;
+    s << "Could not find a UUID for id " << id << ".";
+    throw s.str ();
+  }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 void Task::getDependencies (std::vector <int>& all) const
 {

src/Task.h

@@ -75,6 +75,7 @@ public:
 
   void addDependency (int);
   void removeDependency (int);
+  void removeDependency (const std::string&);
   void getDependencies (std::vector <int>&) const;
   void getDependencies (std::vector <std::string>&) const;