Added constructor for EventManger that requires a single event with no children and a list of Resources ordered by dependency. Updated main and tests to match.

graph.go

@@ -2,6 +2,7 @@ package main
 
 import (
   "fmt"
+  "log"
   "errors"
   "sync"
   graphql "github.com/graph-gophers/graphql-go"
@@ -112,6 +113,10 @@ func (resource * BaseResource) Update() error {
     }
   }
 
+  if resource.lock_holder != nil {
+    resource.lock_holder.Update()
+  }
+
   return nil
 }
 
@@ -133,7 +138,7 @@ type Resource interface {
   AddParent(parent Resource) error
   Children() []Resource
   Parents() []Resource
-  Lock() error
+  Lock(event Event) error
   Unlock() error
 }
 
@@ -141,30 +146,30 @@ type BaseResource struct {
   BaseNode
   parents []Resource
   children []Resource
-  locked bool
+  lock_holder Event
   state_lock sync.Mutex
 }
 
 // Grab the state mutex and check the state, if unlocked continue to hold the mutex while doing the same for children
 // When the bottom of a tree is reached(no more children) go back up and set the lock state
-func (resource * BaseResource) Lock() error {
+func (resource * BaseResource) Lock(event Event) error {
   var err error = nil
   locked := false
 
   resource.state_lock.Lock()
-  if resource.locked == true {
+  if resource.lock_holder != nil {
     err = errors.New("Resource already locked")
   } else {
     all_children_locked := true
     for _, child := range resource.Children() {
-      err = child.Lock()
+      err = child.Lock(event)
       if err != nil {
         all_children_locked = false
         break
       }
     }
     if all_children_locked == true {
-      resource.locked = true
+      resource.lock_holder = event
       locked = true
     }
   }
@@ -183,7 +188,7 @@ func (resource * BaseResource) Unlock() error {
   unlocked := false
 
   resource.state_lock.Lock()
-  if resource.locked == false {
+  if resource.lock_holder == nil {
     err = errors.New("Resource already unlocked")
   } else {
     all_children_unlocked := true
@@ -195,7 +200,7 @@ func (resource * BaseResource) Unlock() error {
       }
     }
     if all_children_unlocked == true{
-      resource.locked = false
+      resource.lock_holder = nil
       unlocked = true
     }
   }
@@ -348,12 +353,26 @@ type EventManager struct {
   root_event Event
 }
 
-func NewEventManager() * EventManager {
-  state := &EventManager{
+// root_event's requirements must be in dag_nodes, and dag_nodes must be ordered by dependency(no children first)
+func NewEventManager(root_event Event, dag_nodes []Resource) * EventManager {
+
+  manager := &EventManager{
     dag_nodes: map[graphql.ID]Resource{},
     root_event: nil,
   }
-  return state;
+
+  // Construct the DAG
+  for _, resource := range dag_nodes {
+    err := manager.AddResource(resource)
+    if err != nil {
+      log.Printf("Failed to add %s to EventManager: %s", resource.ID(), err)
+      return nil
+    }
+  }
+
+  manager.AddEvent(nil, root_event)
+
+  return manager;
 }
 
 func (manager * EventManager) FindResource(id graphql.ID) Resource {
@@ -399,14 +418,10 @@ func (manager * EventManager) AddResource(resource Resource) error {
 // Add resources created by the event to the DAG
 // Add child to parent
 func (manager * EventManager) AddEvent(parent Event, child Event) error {
-  if manager.root_event.FindChild(child.ID()) != nil {
-    error_str := fmt.Sprintf("Event %s already exists in the event tree, can not add again", child.ID())
-    return errors.New(error_str)
-  }
-
-  if manager.root_event.FindChild(parent.ID()) == nil {
-    error_str := fmt.Sprintf("Event %s is not present in the event tree, cannot add %s as child", parent.ID(), child.ID())
-    return errors.New(error_str)
+  if child == nil {
+    return errors.New("Cannot add nil Event to EventManager")
+  } else if len(child.Children()) != 0 {
+    return errors.New("Adding events recursively not implemented")
   }
 
   for _, resource := range child.RequiredResources() {
@@ -425,7 +440,28 @@ func (manager * EventManager) AddEvent(parent Event, child Event) error {
     }
   }
 
-  parent.AddChild(child)
+  if manager.root_event == nil && parent != nil {
+    error_str := fmt.Sprintf("EventManager has no root, so can't add event to parent")
+    return errors.New(error_str)
+  } else if manager.root_event != nil && parent == nil {
+    // TODO
+    return errors.New("Replacing root event not implemented")
+  } else if manager.root_event == nil && parent == nil {
+    manager.root_event = child
+  } else {
+    if manager.root_event.FindChild(parent.ID()) == nil {
+      error_str := fmt.Sprintf("Event %s is not present in the event tree, cannot add %s as child", parent.ID(), child.ID())
+      return errors.New(error_str)
+    }
+
+    if manager.root_event.FindChild(child.ID()) != nil {
+      error_str := fmt.Sprintf("Event %s already exists in the event tree, can not add again", child.ID())
+      return errors.New(error_str)
+    }
+
+    parent.AddChild(child)
+  }
+
   return nil
 }
 

graph_test.go

@@ -50,9 +50,9 @@ func TestNewResourceAdd(t *testing.T) {
   description := "A resource for testing"
   children := []Resource{}
 
+  root_event := NewEvent("", "", []Resource{})
   test_resource := NewResource(name, description, children)
-  event_manager := NewEventManager()
-  event_manager.AddResource(test_resource)
+  event_manager := NewEventManager(root_event, []Resource{test_resource})
   res := event_manager.FindResource(test_resource.ID())
 
   if res == nil {
@@ -65,56 +65,48 @@ func TestNewResourceAdd(t *testing.T) {
 }
 
 func TestDoubleResourceAdd(t * testing.T) {
+  root_event := NewEvent("", "", []Resource{})
   test_resource := NewResource("", "", []Resource{})
-  event_manager := NewEventManager()
-  err_1 := event_manager.AddResource(test_resource)
-  err_2 := event_manager.AddResource(test_resource)
+  event_manager := NewEventManager(root_event, []Resource{test_resource})
+  err := event_manager.AddResource(test_resource)
 
-  if err_1 != nil {
-    t.Fatalf("First AddResource returned error %s", err_1)
-  }
-
-  if err_2 == nil {
+  if err == nil {
     t.Fatal("Second AddResource returned nil")
   }
 }
 
 func TestMissingResourceAdd(t * testing.T) {
+  root_event := NewEvent("", "", []Resource{})
   r1 := NewResource("r1", "", []Resource{})
   r2 := NewResource("r2", "", []Resource{r1})
 
-  event_manager := NewEventManager()
+  event_manager := NewEventManager(root_event, []Resource{})
   err := event_manager.AddResource(r2)
   if err == nil {
     t.Fatal("AddResource with missing child returned nil")
   }
 }
 
-func TestTieredResourceAdd(t * testing.T) {
+func TestTieredResource(t * testing.T) {
+  root_event := NewEvent("", "", []Resource{})
   r1 := NewResource("r1", "", []Resource{})
   r2 := NewResource("r2", "", []Resource{r1})
 
-  event_manager := NewEventManager()
-  err_1 := event_manager.AddResource(r1)
-  err_2 := event_manager.AddResource(r2)
-  if err_1 != nil || err_2 != nil {
-    t.Fatal("Failed adding tiered resource")
+  event_manager := NewEventManager(root_event, []Resource{r1, r2})
+  if event_manager == nil {
+    t.Fatal("Failed to create event manager with tiered resources")
   }
 }
 
 func TestResourceUpdate(t * testing.T) {
+  root_event := NewEvent("", "", []Resource{})
   r1 := NewResource("r1", "", []Resource{})
   r2 := NewResource("r2", "", []Resource{})
   r3 := NewResource("r3", "", []Resource{r1, r2})
   r4 := NewResource("r4", "", []Resource{r3})
 
-  event_manager := NewEventManager()
-  err_1 := event_manager.AddResource(r1)
-  err_2 := event_manager.AddResource(r2)
-  err_3 := event_manager.AddResource(r3)
-  err_4 := event_manager.AddResource(r4)
-
-  if err_1 != nil || err_2 != nil || err_3 != nil || err_4 != nil {
+  event_manager := NewEventManager(root_event, []Resource{r1, r2, r3, r4})
+  if event_manager == nil {
     t.Fatal("Failed to add initial tiered resources for test")
   }
 
@@ -145,41 +137,44 @@ func TestResourceUpdate(t * testing.T) {
   (*graph_tester)(t).CheckForNil(r4_l)
 }
 
+func TestAddEvent(t * testing.T) {
+
+}
+
 func TestLockResource(t * testing.T) {
+  root_event := NewEvent("", "", []Resource{})
   r1 := NewResource("r1", "", []Resource{})
   r2 := NewResource("r2", "", []Resource{})
   r3 := NewResource("r3", "", []Resource{r1, r2})
   r4 := NewResource("r3", "", []Resource{r1, r2})
 
-  event_manager := NewEventManager()
-  err_1 := event_manager.AddResource(r1)
-  err_2 := event_manager.AddResource(r2)
-  err_3 := event_manager.AddResource(r3)
-  err_4 := event_manager.AddResource(r4)
+  event_manager := NewEventManager(root_event, []Resource{r1, r2, r3, r4})
 
-  if err_1 != nil || err_2 != nil || err_3 != nil || err_4 != nil {
+  if event_manager == nil {
     t.Fatal("Failed to add initial tiered resources for test")
   }
 
   r1_l := r1.UpdateChannel()
+  rel := root_event.UpdateChannel()
 
-  err := r3.Lock()
+  err := r3.Lock(root_event)
   if err != nil {
     t.Fatal("Failed to lock r3")
   }
   (*graph_tester)(t).CheckForNil(r1_l)
+  (*graph_tester)(t).CheckForNil(rel)
 
-  err = r3.Lock()
+  err = r3.Lock(root_event)
   if err == nil {
     t.Fatal("Locked r3 after locking r3")
   }
 
-  err = r4.Lock()
+  err = r4.Lock(root_event)
   if err == nil {
     t.Fatal("Locked r4 after locking r3")
   }
 
-  err = r1.Lock()
+  err = r1.Lock(root_event)
   if err == nil {
     t.Fatal("Locked r1 after locking r3")
   }
@@ -189,16 +184,19 @@ func TestLockResource(t * testing.T) {
     t.Fatal("Failed to unlock r3")
   }
   (*graph_tester)(t).CheckForNil(r1_l)
+  (*graph_tester)(t).CheckForNil(rel)
 
-  err = r4.Lock()
+  err = r4.Lock(root_event)
   if err != nil {
     t.Fatal("Failed to lock r4 after unlocking r3")
   }
   (*graph_tester)(t).CheckForNil(r1_l)
+  (*graph_tester)(t).CheckForNil(rel)
 
   err = r4.Unlock()
   if err != nil {
     t.Fatal("Failed to unlock r4")
   }
   (*graph_tester)(t).CheckForNil(r1_l)
+  (*graph_tester)(t).CheckForNil(rel)
 }

main.go

@@ -5,7 +5,7 @@ import (
 )
 
 func fake_data() * EventManager {
-  event_manager := NewEventManager()
+  resources := []Resource{}
 
   teams := []*Team{}
   teams = append(teams, NewTeam("6659", "A", []string{"jimmy"}))
@@ -22,25 +22,20 @@ func fake_data() * EventManager {
   teams = append(teams, NewTeam("315",  "Z", []string{"emily"}))
 
   for _, team := range teams {
-    err := event_manager.AddResource(team)
-    if err != nil {
-      log.Print(err)
-    }
+    resources = append(resources, team)
   }
 
-
-  alliances := []Resource{}
   for i, team := range teams[:len(teams)-1] {
     for _, team2 := range teams[i+1:] {
       alliance := NewAlliance(team, team2)
-      alliances = append(alliances, alliance)
-      err := event_manager.AddResource(alliance)
-      if err != nil {
-        log.Print(err)
-      }
+      resources = append(resources, alliance)
     }
   }
 
+  root_event := NewEvent("root_event", "", []Resource{})
+
+  event_manager := NewEventManager(root_event, resources)
+
   return event_manager
 }