Changed context to dynamically load nodes as they're signalled

context.go

@@ -3,6 +3,7 @@ package graphvent
 import (
   badger "github.com/dgraph-io/badger/v3"
   "fmt"
+  "errors"
   "runtime"
 )
 
@@ -86,21 +87,38 @@ func (ctx *Context) RegisterExtension(ext_type ExtType, load_fn ExtensionLoadFun
   return nil
 }
 
-// Route a Signal to dest. Currently only local context routing is supported
-func (ctx *Context) Send(source NodeID, dest NodeID, signal Signal) error {
-  target, exists := ctx.Nodes[dest]
+var NodeNotFoundError = errors.New("Node not found in DB")
+
+func (ctx *Context) GetNode(id NodeID) (*Node, error) {
+  target, exists := ctx.Nodes[id]
   if exists == false {
-    return fmt.Errorf("%s does not exist, cannot signal it", dest)
+    var err error
+    target, err = LoadNode(ctx, id)
+    if err != nil {
+      return nil, err
+    }
   }
-  select {
-  case target.MsgChan <- Msg{source, signal}:
-  default:
-    buf := make([]byte, 4096)
-    n := runtime.Stack(buf, false)
-    stack_str := string(buf[:n])
-    return fmt.Errorf("SIGNAL_OVERFLOW: %s - %s", dest, stack_str)
+  return target, nil
+}
+
+// Route a Signal to dest. Currently only local context routing is supported
+func (ctx *Context) Send(source NodeID, dest NodeID, signal Signal) error {
+  target, err := ctx.GetNode(dest)
+  if err == nil {
+    select {
+    case target.MsgChan <- Msg{source, signal}:
+    default:
+      buf := make([]byte, 4096)
+      n := runtime.Stack(buf, false)
+      stack_str := string(buf[:n])
+      return fmt.Errorf("SIGNAL_OVERFLOW: %s - %s", dest, stack_str)
+    }
+    return nil
+  } else if errors.Is(err, NodeNotFoundError) {
+    // TODO: Handle finding nodes in other contexts
+    return err
   }
-  return nil
+  return err
 }
 
 // Create a new Context with the base library content added

gql_test.go

@@ -34,7 +34,7 @@ func TestGQLDB(t * testing.T) {
   err = ctx.Send(gql.ID, gql.ID, StopSignal)
   fatalErr(t, err)
 
-  (*GraphTester)(t).WaitForStatus(ctx, listener_ext.Chan, "stopped", 100*time.Millisecond, "Didn't receive stopped on listener")
+  (*GraphTester)(t).WaitForStatus(ctx, listener_ext, "stopped", 100*time.Millisecond, "Didn't receive stopped on listener")
 
   ser1, err := gql.Serialize()
   ser2, err := u1.Serialize()
@@ -49,7 +49,7 @@ func TestGQLDB(t * testing.T) {
   fatalErr(t, err)
   err = ctx.Send(gql_loaded.ID, gql_loaded.ID, StopSignal)
   fatalErr(t, err)
-  (*GraphTester)(t).WaitForStatus(ctx, listener_ext.Chan, "stopped", 100*time.Millisecond, "Didn't receive stopped on update_channel_2")
+  (*GraphTester)(t).WaitForStatus(ctx, listener_ext, "stopped", 100*time.Millisecond, "Didn't receive stopped on update_channel_2")
 
 }
 

graph_test.go

@@ -13,11 +13,11 @@ import (
 type GraphTester testing.T
 const listner_timeout = 50 * time.Millisecond
 
-func (t * GraphTester) WaitForStatus(ctx * Context, listener chan Signal, status string, timeout time.Duration, str string) Signal {
+func (t * GraphTester) WaitForStatus(ctx * Context, listener *ListenerExt, status string, timeout time.Duration, str string) Signal {
   timeout_channel := time.After(timeout)
   for true {
     select {
-    case signal := <- listener:
+    case signal := <- listener.Chan:
       if signal == nil {
         ctx.Log.Logf("test", "SIGNAL_CHANNEL_CLOSED: %s", listener)
         t.Fatal(str)
@@ -25,6 +25,8 @@ func (t * GraphTester) WaitForStatus(ctx * Context, listener chan Signal, status
       if signal.Type() == "status" {
         sig, ok := signal.(StatusSignal)
         if ok == true {
+
+
           ctx.Log.Logf("test", "Status received: %s", sig.Status)
           if sig.Status == status {
             return signal
@@ -42,10 +44,10 @@ func (t * GraphTester) WaitForStatus(ctx * Context, listener chan Signal, status
   return nil
 }
 
-func (t * GraphTester) CheckForNone(listener chan Signal, str string) {
+func (t * GraphTester) CheckForNone(listener *ListenerExt, str string) {
   timeout := time.After(listner_timeout)
   select {
-  case sig := <- listener:
+  case sig := <- listener.Chan:
     pprof.Lookup("goroutine").WriteTo(os.Stdout, 1)
     t.Fatal(fmt.Sprintf("%s : %+v", str, sig))
   case <-timeout:

lockable_test.go

@@ -4,10 +4,35 @@ import (
   "testing"
 )
 
-func TestLockableLink(t *testing.T) {
+const TestLockableType = NodeType("TEST_LOCKABLE")
+func lockableTestContext(t *testing.T) *Context {
   ctx := logTestContext(t, []string{"lockable", "signal"})
-  LockableType := NodeType("TEST_LOCKABLE")
-  err := ctx.RegisterNodeType(LockableType, []ExtType{LockableExtType})
+
+  err := ctx.RegisterNodeType(TestLockableType, []ExtType{ACLExtType, LockableExtType, ListenerExtType})
   fatalErr(t, err)
+
+  return ctx
+}
+
+
+var link_policy = NewAllNodesPolicy([]string{"link", "status"})
+
+func Test(t *testing.T) {
+  ctx := lockableTestContext(t)
+
+  l1_listener := NewListenerExt(10)
+  l1 := NewNode(ctx, RandID(), TestLockableType, nil,
+                 l1_listener,
+                 NewACLExt(&link_policy),
+                 NewLockableExt(nil, nil, nil, nil),
+               )
+  l2_listener := NewListenerExt(10)
+  l2 := NewNode(ctx, RandID(), TestLockableType, nil,
+                 l2_listener,
+                 NewACLExt(&link_policy),
+                 NewLockableExt(nil, nil, nil, nil),
+               )
+
+  ctx.Send(l1.ID, l2.ID, NewLinkSignal("start", l1.ID))
 }
 

node.go

@@ -2,6 +2,7 @@ package graphvent
 
 import (
   "time"
+  "errors"
   "reflect"
   "github.com/google/uuid"
   badger "github.com/dgraph-io/badger/v3"
@@ -458,14 +459,7 @@ func WriteNode(ctx *Context, node *Node) error {
 }
 
 func LoadNode(ctx * Context, id NodeID) (*Node, error) {
-  ctx.Log.Logf("db", "LOOKING_FOR_NODE: %s", id)
-  node, exists := ctx.Nodes[id]
-  if exists == true {
-    ctx.Log.Logf("db", "NODE_ALREADY_LOADED: %s", id)
-    return node,nil
-  }
   ctx.Log.Logf("db", "LOADING_NODE: %s", id)
-
   var bytes []byte
   err := ctx.DB.View(func(txn *badger.Txn) error {
     item, err := txn.Get(id.Serialize())
@@ -478,7 +472,9 @@ func LoadNode(ctx * Context, id NodeID) (*Node, error) {
       return nil
     })
   })
-  if err != nil {
+  if errors.Is(err, badger.ErrKeyNotFound) {
+    return nil, NodeNotFoundError
+  }else if err != nil {
     return nil, err
   }
 
@@ -494,7 +490,7 @@ func LoadNode(ctx * Context, id NodeID) (*Node, error) {
   }
 
   next_signal, timeout_chan := SoonestSignal(node_db.QueuedSignals)
-  node = &Node{
+  node := &Node{
     ID: id,
     Type: node_type.Type,
     Extensions: map[ExtType]Extension{},