Vote-/UTXO-layer and branch unit tests (#430)

* Feat: initial commit

* Feat: added setPreferred to TransactionMetadata

* Feat: added a Conflicting() method to the transactionMetadata

* Fix: fixed logic bug

* Feat: refactored fcob

* Refactor: refactored additional code

* Fix: fixed a bug in ForeachConsumers

* Refactor: cleaned up code

* Feat: implemented FCOB consensus into the valuetransfer dapp

* Refactor: refactored FCOB

* Docs: added some additional comments

* Docs: fixed comments

* add branch manager conflict test

* cleans failing test

* Refactor: commit before branch change

* Fix: fixed bug in AggregateBranches

* assert aggr. branch IDs

* expands branch conflict detection test

* add visualisation of branch graph of test

* Feat: added PayloadLiked Event

* Refactor: fixed some missing comments + added liked to marshal

* Feat: reworked the preferred and liked propagation

* Refactor: cleaned up some logic

* Refactor: simplified code

* Refactor: cleaned up more stuff :P

* Refactor: refactor

* Feat: moved test + refactored fcob

* adds more tests

* fixes liked state not getting updated correctly of conflict members

* adds additional liked/preferred propagation test

* Fix: fixed missing preferred propagation to aggregated branches

* Fix: fixed a few bugs in liked propagation

* adapt to new hive.go version

* upgrade hive.go

* Feat: started implementing a wallet

* Feat: extended wallet files

* remove weird test

* use mem db for tests

* more tests

* did someone say more tests?

* Fix: fixed bug in findDeepestCommonDescendants

* simply test

* adds additional test

* use store backed sequence

* add option to use in-memory database

* address review comments

* Fix: fixed missing events in branchmanaer

* Feat: propagate changes from branch to transaction

* Feat: started implementing confirmed propagation

* Fix: fixed unreachable code

* Refactor: refactored some code according to wolfgangs review

* Refactor: cleaned up the code according to DRY

* Refactor: refactored according to wollac

* Refactor: refactored according to wollac

* Refactor: refactored according to wollac

* Refactor: refactored the code to make it more readable

* Refactor: added some doc comments + cleaned up some more code

* fix weird duplicated code

* fixes shadow dec.

* check modified flags

Co-authored-by: Hans Moog <hm@mkjc.net>
Co-authored-by: Wolfgang Welz <welzwo@gmail.com>

dapps/valuetransfers/packages/branchmanager/branch.go

@@ -214,7 +214,6 @@ func (branch *Branch) setPreferred(preferred bool) (modified bool) {
 	branch.preferred = preferred
 	branch.SetModified()
 	modified = true
-
 	return
 }
 
@@ -246,8 +245,7 @@ func (branch *Branch) setLiked(liked bool) (modified bool) {
 	branch.liked = liked
 	branch.SetModified()
 	modified = true
-
-	return branch.liked
+	return
 }
 
 // Finalized returns true if the branch has been marked as finalized.

dapps/valuetransfers/packages/branchmanager/branchmanager.go

@@ -251,6 +251,8 @@ func (branchManager *BranchManager) BranchesConflicting(branchIds ...BranchID) (
 					}
 
 					if conflictMember.BranchID() == currentBranchID {
+						cachedConflictMember.Release()
+
 						continue
 					}
 
@@ -392,7 +394,7 @@ func (branchManager *BranchManager) setBranchPreferred(cachedBranch *CachedBranc
 	if !preferred {
 		if modified = branch.setPreferred(false); modified {
 			branchManager.Events.BranchUnpreferred.Trigger(cachedBranch)
-
+			branchManager.propagatePreferredChangesToAggregatedChildBranches(branch.ID())
 			branchManager.propagateDislikeToFutureCone(cachedBranch.Retain())
 		}
 
@@ -417,12 +419,63 @@ func (branchManager *BranchManager) setBranchPreferred(cachedBranch *CachedBranc
 	}
 
 	branchManager.Events.BranchPreferred.Trigger(cachedBranch)
-
+	branchManager.propagatePreferredChangesToAggregatedChildBranches(branch.ID())
 	err = branchManager.propagateLike(cachedBranch.Retain())
 
 	return
 }
 
+// propagatePreferredChangesToAggregatedChildBranches recursively updates the preferred flag of all descendants of the
+// given Branch.
+func (branchManager *BranchManager) propagatePreferredChangesToAggregatedChildBranches(parentBranchID BranchID) {
+	// initialize stack with children of the passed in parent Branch
+	branchStack := list.New()
+	branchManager.ChildBranches(parentBranchID).Consume(func(childBranchReference *ChildBranch) {
+		branchStack.PushBack(childBranchReference.ChildID())
+	})
+
+	// iterate through child branches and propagate changes
+	for branchStack.Len() >= 1 {
+		// retrieve first element from the stack
+		currentEntry := branchStack.Front()
+		currentChildBranchID := currentEntry.Value.(BranchID)
+		branchStack.Remove(currentEntry)
+
+		// load branch from storage
+		cachedAggregatedChildBranch := branchManager.Branch(currentChildBranchID)
+
+		// only process branches that could be loaded and that are aggregated branches
+		if aggregatedChildBranch := cachedAggregatedChildBranch.Unwrap(); aggregatedChildBranch != nil && aggregatedChildBranch.IsAggregated() {
+			// determine if all parents are liked
+			allParentsPreferred := true
+			for _, parentID := range aggregatedChildBranch.ParentBranches() {
+				if allParentsPreferred {
+					allParentsPreferred = allParentsPreferred && branchManager.Branch(parentID).Consume(func(parentBranch *Branch) {
+						allParentsPreferred = allParentsPreferred && parentBranch.Preferred()
+					})
+				}
+			}
+
+			// trigger events and check children if the branch was updated
+			if aggregatedChildBranch.setPreferred(allParentsPreferred) {
+				if allParentsPreferred {
+					branchManager.Events.BranchPreferred.Trigger(cachedAggregatedChildBranch)
+				} else {
+					branchManager.Events.BranchUnpreferred.Trigger(cachedAggregatedChildBranch)
+				}
+
+				// schedule checks for children if preferred flag was updated
+				branchManager.ChildBranches(currentChildBranchID).Consume(func(childBranchReference *ChildBranch) {
+					branchStack.PushBack(childBranchReference.ChildID())
+				})
+			}
+		}
+
+		// release the branch when we are done
+		cachedAggregatedChildBranch.Release()
+	}
+}
+
 func (branchManager *BranchManager) setBranchLiked(cachedBranch *CachedBranch, liked bool) (modified bool, err error) {
 	defer cachedBranch.Release()
 	branch := cachedBranch.Unwrap()
@@ -611,7 +664,7 @@ func (branchManager *BranchManager) determineAggregatedBranchDetails(deepestComm
 			continue
 		}
 
-		if branch.IsAggregated() {
+		if !branch.IsAggregated() {
 			aggregatedBranchConflictParents[branchID] = cachedBranch
 
 			continue
@@ -781,8 +834,6 @@ func (branchManager *BranchManager) findDeepestCommonDescendants(branches ...Bra
 					cachedAggregatedBranch.Release()
 
 					result[branchID] = cachedBranch
-
-					return nil
 				}
 			}