Implement changing from and to vertices in relationships (#1221)

include/_mgp.hpp

@@ -255,6 +255,16 @@ inline mgp_edge *graph_create_edge(mgp_graph *graph, mgp_vertex *from, mgp_verte
   return MgInvoke<mgp_edge *>(mgp_graph_create_edge, graph, from, to, type, memory);
 }
 
+inline mgp_edge *graph_edge_set_from(struct mgp_graph *graph, struct mgp_edge *e, struct mgp_vertex *new_from,
+                                     mgp_memory *memory) {
+  return MgInvoke<mgp_edge *>(mgp_graph_edge_set_from, graph, e, new_from, memory);
+}
+
+inline mgp_edge *graph_edge_set_to(struct mgp_graph *graph, struct mgp_edge *e, struct mgp_vertex *new_to,
+                                   mgp_memory *memory) {
+  return MgInvoke<mgp_edge *>(mgp_graph_edge_set_to, graph, e, new_to, memory);
+}
+
 inline void graph_delete_edge(mgp_graph *graph, mgp_edge *edge) { MgInvokeVoid(mgp_graph_delete_edge, graph, edge); }
 
 inline mgp_vertex *graph_get_vertex_by_id(mgp_graph *g, mgp_vertex_id id, mgp_memory *memory) {

include/mg_procedure.h

@@ -888,6 +888,22 @@ enum mgp_error mgp_graph_detach_delete_vertex(struct mgp_graph *graph, struct mg
 enum mgp_error mgp_graph_create_edge(struct mgp_graph *graph, struct mgp_vertex *from, struct mgp_vertex *to,
                                      struct mgp_edge_type type, struct mgp_memory *memory, struct mgp_edge **result);
 
+/// Change edge from vertex
+/// Return mgp_error::MGP_ERROR_IMMUTABLE_OBJECT if `graph` is immutable.
+/// Return mgp_error::MGP_ERROR_UNABLE_TO_ALLOCATE if unable to allocate a mgp_edge.
+/// Return mgp_error::MGP_ERROR_DELETED_OBJECT if `from` or `to` has been deleted.
+/// Return mgp_error::MGP_ERROR_SERIALIZATION_ERROR if `from` or `to` has been modified by another transaction.
+enum mgp_error mgp_graph_edge_set_from(struct mgp_graph *graph, struct mgp_edge *e, struct mgp_vertex *new_from,
+                                       struct mgp_memory *memory, struct mgp_edge **result);
+
+/// Change edge to vertex
+/// Return mgp_error::MGP_ERROR_IMMUTABLE_OBJECT if `graph` is immutable.
+/// Return mgp_error::MGP_ERROR_UNABLE_TO_ALLOCATE if unable to allocate a mgp_edge.
+/// Return mgp_error::MGP_ERROR_DELETED_OBJECT if `from` or `to` has been deleted.
+/// Return mgp_error::MGP_ERROR_SERIALIZATION_ERROR if `from` or `to` has been modified by another transaction.
+enum mgp_error mgp_graph_edge_set_to(struct mgp_graph *graph, struct mgp_edge *e, struct mgp_vertex *new_to,
+                                     struct mgp_memory *memory, struct mgp_edge **result);
+
 /// Delete an edge from the graph.
 /// Return mgp_error::MGP_ERROR_IMMUTABLE_OBJECT if `graph` is immutable.
 /// Return mgp_error::MGP_ERROR_SERIALIZATION_ERROR if `edge`, its source or destination vertex has been modified by

include/mgp.hpp

@@ -256,6 +256,10 @@ class Graph {
   void DetachDeleteNode(const Node &node);
   /// @brief Creates a relationship of type `type` between nodes `from` and `to` and adds it to the graph.
   Relationship CreateRelationship(const Node &from, const Node &to, const std::string_view type);
+  /// @brief Changes a relationship from node.
+  void SetFrom(Relationship &relationship, const Node &new_from);
+  /// @brief Changes a relationship to node.
+  void SetTo(Relationship &relationship, const Node &new_to);
   /// @brief Deletes a relationship from the graph.
   void DeleteRelationship(const Relationship &relationship);
 
@@ -2009,6 +2013,18 @@ inline Relationship Graph::CreateRelationship(const Node &from, const Node &to,
   return relationship;
 }
 
+inline void Graph::SetFrom(Relationship &relationship, const Node &new_from) {
+  mgp_edge *edge = mgp::MemHandlerCallback(mgp::graph_edge_set_from, graph_, relationship.ptr_, new_from.ptr_);
+  relationship = Relationship(edge);
+  mgp::edge_destroy(edge);
+}
+
+inline void Graph::SetTo(Relationship &relationship, const Node &new_to) {
+  mgp_edge *edge = mgp::MemHandlerCallback(mgp::graph_edge_set_to, graph_, relationship.ptr_, new_to.ptr_);
+  relationship = Relationship(edge);
+  mgp::edge_destroy(edge);
+}
+
 inline void Graph::DeleteRelationship(const Relationship &relationship) {
   mgp::graph_delete_edge(graph_, relationship.ptr_);
 }

src/query/db_accessor.cpp

@@ -76,6 +76,24 @@ SubgraphDbAccessor::DetachRemoveVertex(  // NOLINT(readability-convert-member-fu
       "Vertex holds only partial information about edges. Cannot detach delete safely while using projected graph."};
 }
 
+storage::Result<EdgeAccessor> SubgraphDbAccessor::EdgeSetFrom(EdgeAccessor *edge, SubgraphVertexAccessor *new_from) {
+  VertexAccessor *new_from_impl = &new_from->impl_;
+  if (!this->graph_->ContainsVertex(*new_from_impl)) {
+    throw std::logic_error{"Projected graph must contain the new `from` vertex!"};
+  }
+  auto result = db_accessor_.EdgeSetFrom(edge, new_from_impl);
+  return result;
+}
+
+storage::Result<EdgeAccessor> SubgraphDbAccessor::EdgeSetTo(EdgeAccessor *edge, SubgraphVertexAccessor *new_to) {
+  VertexAccessor *new_to_impl = &new_to->impl_;
+  if (!this->graph_->ContainsVertex(*new_to_impl)) {
+    throw std::logic_error{"Projected graph must contain the new `to` vertex!"};
+  }
+  auto result = db_accessor_.EdgeSetTo(edge, new_to_impl);
+  return result;
+}
+
 storage::Result<std::optional<VertexAccessor>> SubgraphDbAccessor::RemoveVertex(
     SubgraphVertexAccessor *subgraphvertex_accessor) {
   VertexAccessor *vertex_accessor = &subgraphvertex_accessor->impl_;

src/query/db_accessor.hpp

@@ -380,6 +380,18 @@ class DbAccessor final {
     return EdgeAccessor(*maybe_edge);
   }
 
+  storage::Result<EdgeAccessor> EdgeSetFrom(EdgeAccessor *edge, VertexAccessor *new_from) {
+    auto changed_edge = accessor_->EdgeSetFrom(&edge->impl_, &new_from->impl_);
+    if (changed_edge.HasError()) return storage::Result<EdgeAccessor>(changed_edge.GetError());
+    return EdgeAccessor(*changed_edge);
+  }
+
+  storage::Result<EdgeAccessor> EdgeSetTo(EdgeAccessor *edge, VertexAccessor *new_to) {
+    auto changed_edge = accessor_->EdgeSetTo(&edge->impl_, &new_to->impl_);
+    if (changed_edge.HasError()) return storage::Result<EdgeAccessor>(changed_edge.GetError());
+    return EdgeAccessor(*changed_edge);
+  }
+
   storage::Result<std::optional<EdgeAccessor>> RemoveEdge(EdgeAccessor *edge) {
     auto res = accessor_->DeleteEdge(&edge->impl_);
     if (res.HasError()) {
@@ -549,6 +561,10 @@ class SubgraphDbAccessor final {
   storage::Result<EdgeAccessor> InsertEdge(SubgraphVertexAccessor *from, SubgraphVertexAccessor *to,
                                            const storage::EdgeTypeId &edge_type);
 
+  storage::Result<EdgeAccessor> EdgeSetFrom(EdgeAccessor *edge, SubgraphVertexAccessor *new_from);
+
+  storage::Result<EdgeAccessor> EdgeSetTo(EdgeAccessor *edge, SubgraphVertexAccessor *new_to);
+
   storage::Result<std::optional<std::pair<VertexAccessor, std::vector<EdgeAccessor>>>> DetachRemoveVertex(
       SubgraphVertexAccessor *vertex_accessor);
 

src/query/procedure/mg_procedure_impl.cpp

@@ -2721,6 +2721,83 @@ mgp_error mgp_graph_create_edge(mgp_graph *graph, mgp_vertex *from, mgp_vertex *
       result);
 }
 
+namespace {
+
+mgp_edge *EdgeSet(auto *e, auto *new_vertex, auto *memory, auto *graph, bool set_from) {
+  auto *ctx = graph->ctx;
+#ifdef MG_ENTERPRISE
+  if (memgraph::license::global_license_checker.IsEnterpriseValidFast() && ctx && ctx->auth_checker &&
+      !ctx->auth_checker->Has(e->impl, memgraph::query::AuthQuery::FineGrainedPrivilege::CREATE_DELETE)) {
+    throw AuthorizationException{"Insufficient permissions for changing an edge!"};
+  }
+#endif
+  if (!MgpGraphIsMutable(*graph)) {
+    throw ImmutableObjectException{"Cannot change the edge because the graph is immutable!"};
+  }
+
+  auto edge = std::visit(
+      memgraph::utils::Overloaded{
+          [&e, &new_vertex, &set_from](
+              memgraph::query::DbAccessor *accessor) -> memgraph::storage::Result<memgraph::query::EdgeAccessor> {
+            if (set_from) {
+              return accessor->EdgeSetFrom(&e->impl, &std::get<memgraph::query::VertexAccessor>(new_vertex->impl));
+            }
+            return accessor->EdgeSetTo(&e->impl, &std::get<memgraph::query::VertexAccessor>(new_vertex->impl));
+          },
+          [&e, &new_vertex, &set_from](memgraph::query::SubgraphDbAccessor *accessor)
+              -> memgraph::storage::Result<memgraph::query::EdgeAccessor> {
+            if (set_from) {
+              return accessor->EdgeSetFrom(&e->impl,
+                                           &std::get<memgraph::query::SubgraphVertexAccessor>(new_vertex->impl));
+            }
+            return accessor->EdgeSetTo(&e->impl, &std::get<memgraph::query::SubgraphVertexAccessor>(new_vertex->impl));
+          }},
+      graph->impl);
+
+  if (edge.HasError()) {
+    switch (edge.GetError()) {
+      case memgraph::storage::Error::NONEXISTENT_OBJECT:
+        LOG_FATAL("Query modules shouldn't have access to nonexistent objects when changing an edge!");
+      case memgraph::storage::Error::DELETED_OBJECT:
+        LOG_FATAL("The edge was already deleted.");
+      case memgraph::storage::Error::PROPERTIES_DISABLED:
+      case memgraph::storage::Error::VERTEX_HAS_EDGES:
+        LOG_FATAL("Unexpected error when removing an edge.");
+      case memgraph::storage::Error::SERIALIZATION_ERROR:
+        throw SerializationException{"Cannot serialize changing an edge."};
+    }
+  }
+
+  if (ctx->trigger_context_collector) {
+    ctx->trigger_context_collector->RegisterDeletedObject(e->impl);
+    ctx->trigger_context_collector->RegisterCreatedObject(*edge);
+  }
+
+  return std::visit(
+      memgraph::utils::Overloaded{
+          [&memory, &edge, &new_vertex](memgraph::query::DbAccessor *) -> mgp_edge * {
+            return NewRawMgpObject<mgp_edge>(memory->impl, edge.GetValue(), new_vertex->graph);
+          },
+          [&memory, &edge, &new_vertex](memgraph::query::SubgraphDbAccessor *db_impl) -> mgp_edge * {
+            const auto v_from = memgraph::query::SubgraphVertexAccessor(edge.GetValue().From(), db_impl->getGraph());
+            const auto v_to = memgraph::query::SubgraphVertexAccessor(edge.GetValue().To(), db_impl->getGraph());
+            return NewRawMgpObject<mgp_edge>(memory->impl, edge.GetValue(), v_from, v_to, new_vertex->graph);
+          }},
+      new_vertex->graph->impl);
+}
+
+}  // namespace
+
+mgp_error mgp_graph_edge_set_from(struct mgp_graph *graph, struct mgp_edge *e, struct mgp_vertex *new_from,
+                                  mgp_memory *memory, mgp_edge **result) {
+  return WrapExceptions([&]() -> mgp_edge * { return EdgeSet(e, new_from, memory, graph, true); }, result);
+}
+
+mgp_error mgp_graph_edge_set_to(struct mgp_graph *graph, struct mgp_edge *e, struct mgp_vertex *new_to,
+                                mgp_memory *memory, mgp_edge **result) {
+  return WrapExceptions([&]() -> mgp_edge * { return EdgeSet(e, new_to, memory, graph, false); }, result);
+}
+
 mgp_error mgp_graph_delete_edge(struct mgp_graph *graph, mgp_edge *edge) {
   return WrapExceptions([=] {
     auto *ctx = graph->ctx;

src/storage/v2/disk/storage.cpp

@@ -36,6 +36,7 @@
 #include "storage/v2/disk/rocksdb_storage.hpp"
 #include "storage/v2/disk/storage.hpp"
 #include "storage/v2/disk/unique_constraints.hpp"
+#include "storage/v2/edge_accessor.hpp"
 #include "storage/v2/edge_import_mode.hpp"
 #include "storage/v2/edge_ref.hpp"
 #include "storage/v2/id_types.hpp"
@@ -1366,6 +1367,16 @@ Result<std::optional<EdgeAccessor>> DiskStorage::DiskAccessor::DeleteEdge(EdgeAc
                                           &storage_->indices_, &storage_->constraints_, config_, true);
 }
 
+Result<EdgeAccessor> DiskStorage::DiskAccessor::EdgeSetFrom(EdgeAccessor * /*edge*/, VertexAccessor * /*new_from*/) {
+  MG_ASSERT(false, "EdgeSetFrom is currently only implemented for InMemory storage");
+  return Error::NONEXISTENT_OBJECT;
+}
+
+Result<EdgeAccessor> DiskStorage::DiskAccessor::EdgeSetTo(EdgeAccessor * /*edge*/, VertexAccessor * /*new_to*/) {
+  MG_ASSERT(false, "EdgeSetTo is currently only implemented for InMemory storage");
+  return Error::NONEXISTENT_OBJECT;
+}
+
 /// TODO: at which storage naming
 /// TODO: this method should also delete the old key
 bool DiskStorage::DiskAccessor::WriteVertexToDisk(const Vertex &vertex) {

src/storage/v2/disk/storage.hpp

@@ -184,6 +184,10 @@ class DiskStorage final : public Storage {
 
     Result<EdgeAccessor> CreateEdge(VertexAccessor *from, VertexAccessor *to, EdgeTypeId edge_type) override;
 
+    Result<EdgeAccessor> EdgeSetFrom(EdgeAccessor *edge, VertexAccessor *new_from) override;
+
+    Result<EdgeAccessor> EdgeSetTo(EdgeAccessor *edge, VertexAccessor *new_to) override;
+
     Result<std::optional<EdgeAccessor>> DeleteEdge(EdgeAccessor *edge) override;
 
     bool LabelIndexExists(LabelId label) const override {

src/storage/v2/inmemory/storage.cpp

@@ -496,12 +496,216 @@ Result<EdgeAccessor> InMemoryStorage::InMemoryAccessor::CreateEdgeEx(VertexAcces
                       &storage_->constraints_, config_);
 }
 
+Result<EdgeAccessor> InMemoryStorage::InMemoryAccessor::EdgeSetFrom(EdgeAccessor *edge, VertexAccessor *new_from) {
+  MG_ASSERT(edge->transaction_ == new_from->transaction_,
+            "EdgeAccessor must be from the same transaction as the new from vertex "
+            "accessor when deleting an edge!");
+  MG_ASSERT(edge->transaction_ == &transaction_,
+            "EdgeAccessor must be from the same transaction as the storage "
+            "accessor when changing an edge!");
+
+  auto *old_from_vertex = edge->from_vertex_;
+  auto *new_from_vertex = new_from->vertex_;
+  auto *to_vertex = edge->to_vertex_;
+
+  if (old_from_vertex->gid == new_from_vertex->gid) return *edge;
+
+  auto edge_ref = edge->edge_;
+  auto edge_type = edge->edge_type_;
+
+  std::unique_lock<utils::RWSpinLock> guard;
+  if (config_.properties_on_edges) {
+    auto *edge_ptr = edge_ref.ptr;
+    guard = std::unique_lock{edge_ptr->lock};
+
+    if (!PrepareForWrite(&transaction_, edge_ptr)) return Error::SERIALIZATION_ERROR;
+
+    if (edge_ptr->deleted) return Error::DELETED_OBJECT;
+  }
+
+  std::unique_lock<utils::RWSpinLock> guard_old_from(old_from_vertex->lock, std::defer_lock);
+  std::unique_lock<utils::RWSpinLock> guard_new_from(new_from_vertex->lock, std::defer_lock);
+  std::unique_lock<utils::RWSpinLock> guard_to(to_vertex->lock, std::defer_lock);
+
+  // lock in increasing gid order, if two vertices have the same gid need to only lock once
+  std::vector<memgraph::storage::Vertex *> vertices{old_from_vertex, new_from_vertex, to_vertex};
+  std::sort(vertices.begin(), vertices.end(), [](auto x, auto y) { return x->gid < y->gid; });
+  vertices.erase(std::unique(vertices.begin(), vertices.end(), [](auto x, auto y) { return x->gid == y->gid; }),
+                 vertices.end());
+
+  for (auto *vertex : vertices) {
+    if (vertex == old_from_vertex) {
+      guard_old_from.lock();
+    } else if (vertex == new_from_vertex) {
+      guard_new_from.lock();
+    } else if (vertex == to_vertex) {
+      guard_to.lock();
+    } else {
+      return Error::NONEXISTENT_OBJECT;
+    }
+  }
+
+  if (!PrepareForWrite(&transaction_, old_from_vertex)) return Error::SERIALIZATION_ERROR;
+  MG_ASSERT(!old_from_vertex->deleted, "Invalid database state!");
+
+  if (!PrepareForWrite(&transaction_, new_from_vertex)) return Error::SERIALIZATION_ERROR;
+  MG_ASSERT(!new_from_vertex->deleted, "Invalid database state!");
+
+  if (to_vertex != old_from_vertex && to_vertex != new_from_vertex) {
+    if (!PrepareForWrite(&transaction_, to_vertex)) return Error::SERIALIZATION_ERROR;
+    MG_ASSERT(!to_vertex->deleted, "Invalid database state!");
+  }
+
+  auto delete_edge_from_storage = [&edge_type, &edge_ref, this](auto *vertex, auto *edges) {
+    std::tuple<EdgeTypeId, Vertex *, EdgeRef> link(edge_type, vertex, edge_ref);
+    auto it = std::find(edges->begin(), edges->end(), link);
+    if (config_.properties_on_edges) {
+      MG_ASSERT(it != edges->end(), "Invalid database state!");
+    } else if (it == edges->end()) {
+      return false;
+    }
+    std::swap(*it, *edges->rbegin());
+    edges->pop_back();
+    return true;
+  };
+
+  auto op1 = delete_edge_from_storage(to_vertex, &old_from_vertex->out_edges);
+  auto op2 = delete_edge_from_storage(old_from_vertex, &to_vertex->in_edges);
+
+  if (config_.properties_on_edges) {
+    MG_ASSERT((op1 && op2), "Invalid database state!");
+  } else {
+    MG_ASSERT((op1 && op2) || (!op1 && !op2), "Invalid database state!");
+    if (!op1 && !op2) {
+      // The edge is already deleted.
+      return Error::DELETED_OBJECT;
+    }
+  }
+
+  CreateAndLinkDelta(&transaction_, old_from_vertex, Delta::AddOutEdgeTag(), edge_type, to_vertex, edge_ref);
+  CreateAndLinkDelta(&transaction_, to_vertex, Delta::AddInEdgeTag(), edge_type, old_from_vertex, edge_ref);
+
+  CreateAndLinkDelta(&transaction_, new_from_vertex, Delta::RemoveOutEdgeTag(), edge_type, to_vertex, edge_ref);
+  new_from_vertex->out_edges.emplace_back(edge_type, to_vertex, edge_ref);
+  CreateAndLinkDelta(&transaction_, to_vertex, Delta::RemoveInEdgeTag(), edge_type, new_from_vertex, edge_ref);
+  to_vertex->in_edges.emplace_back(edge_type, new_from_vertex, edge_ref);
+
+  transaction_.manyDeltasCache.Invalidate(new_from_vertex, edge_type, EdgeDirection::OUT);
+  transaction_.manyDeltasCache.Invalidate(old_from_vertex, edge_type, EdgeDirection::OUT);
+  transaction_.manyDeltasCache.Invalidate(to_vertex, edge_type, EdgeDirection::IN);
+
+  return EdgeAccessor(edge_ref, edge_type, new_from_vertex, to_vertex, &transaction_, &storage_->indices_,
+                      &storage_->constraints_, config_);
+}
+
+Result<EdgeAccessor> InMemoryStorage::InMemoryAccessor::EdgeSetTo(EdgeAccessor *edge, VertexAccessor *new_to) {
+  MG_ASSERT(edge->transaction_ == new_to->transaction_,
+            "EdgeAccessor must be from the same transaction as the new to vertex "
+            "accessor when deleting an edge!");
+  MG_ASSERT(edge->transaction_ == &transaction_,
+            "EdgeAccessor must be from the same transaction as the storage "
+            "accessor when deleting an edge!");
+
+  auto *from_vertex = edge->from_vertex_;
+  auto *old_to_vertex = edge->to_vertex_;
+  auto *new_to_vertex = new_to->vertex_;
+
+  if (old_to_vertex->gid == new_to_vertex->gid) return *edge;
+
+  auto &edge_ref = edge->edge_;
+  auto &edge_type = edge->edge_type_;
+
+  std::unique_lock<utils::RWSpinLock> guard;
+  if (config_.properties_on_edges) {
+    auto *edge_ptr = edge_ref.ptr;
+    guard = std::unique_lock{edge_ptr->lock};
+
+    if (!PrepareForWrite(&transaction_, edge_ptr)) return Error::SERIALIZATION_ERROR;
+
+    if (edge_ptr->deleted) return Error::DELETED_OBJECT;
+  }
+
+  std::unique_lock<utils::RWSpinLock> guard_from(from_vertex->lock, std::defer_lock);
+  std::unique_lock<utils::RWSpinLock> guard_old_to(old_to_vertex->lock, std::defer_lock);
+  std::unique_lock<utils::RWSpinLock> guard_new_to(new_to_vertex->lock, std::defer_lock);
+
+  // lock in increasing gid order, if two vertices have the same gid need to only lock once
+  std::vector<memgraph::storage::Vertex *> vertices{from_vertex, old_to_vertex, new_to_vertex};
+  std::sort(vertices.begin(), vertices.end(), [](auto x, auto y) { return x->gid < y->gid; });
+  vertices.erase(std::unique(vertices.begin(), vertices.end(), [](auto x, auto y) { return x->gid == y->gid; }),
+                 vertices.end());
+
+  for (auto *vertex : vertices) {
+    if (vertex == from_vertex) {
+      guard_from.lock();
+    } else if (vertex == old_to_vertex) {
+      guard_old_to.lock();
+    } else if (vertex == new_to_vertex) {
+      guard_new_to.lock();
+    } else {
+      return Error::NONEXISTENT_OBJECT;
+    }
+  }
+
+  if (!PrepareForWrite(&transaction_, old_to_vertex)) return Error::SERIALIZATION_ERROR;
+  MG_ASSERT(!old_to_vertex->deleted, "Invalid database state!");
+
+  if (!PrepareForWrite(&transaction_, new_to_vertex)) return Error::SERIALIZATION_ERROR;
+  MG_ASSERT(!new_to_vertex->deleted, "Invalid database state!");
+
+  if (from_vertex != old_to_vertex && from_vertex != new_to_vertex) {
+    if (!PrepareForWrite(&transaction_, from_vertex)) return Error::SERIALIZATION_ERROR;
+    MG_ASSERT(!from_vertex->deleted, "Invalid database state!");
+  }
+
+  auto delete_edge_from_storage = [&edge_type, &edge_ref, this](auto *vertex, auto *edges) {
+    std::tuple<EdgeTypeId, Vertex *, EdgeRef> link(edge_type, vertex, edge_ref);
+    auto it = std::find(edges->begin(), edges->end(), link);
+    if (config_.properties_on_edges) {
+      MG_ASSERT(it != edges->end(), "Invalid database state!");
+    } else if (it == edges->end()) {
+      return false;
+    }
+    std::swap(*it, *edges->rbegin());
+    edges->pop_back();
+    return true;
+  };
+
+  auto op1 = delete_edge_from_storage(old_to_vertex, &from_vertex->out_edges);
+  auto op2 = delete_edge_from_storage(from_vertex, &old_to_vertex->in_edges);
+
+  if (config_.properties_on_edges) {
+    MG_ASSERT((op1 && op2), "Invalid database state!");
+  } else {
+    MG_ASSERT((op1 && op2) || (!op1 && !op2), "Invalid database state!");
+    if (!op1 && !op2) {
+      // The edge is already deleted.
+      return Error::DELETED_OBJECT;
+    }
+  }
+
+  CreateAndLinkDelta(&transaction_, from_vertex, Delta::AddOutEdgeTag(), edge_type, old_to_vertex, edge_ref);
+  CreateAndLinkDelta(&transaction_, old_to_vertex, Delta::AddInEdgeTag(), edge_type, from_vertex, edge_ref);
+
+  CreateAndLinkDelta(&transaction_, from_vertex, Delta::RemoveOutEdgeTag(), edge_type, new_to_vertex, edge_ref);
+  from_vertex->out_edges.emplace_back(edge_type, new_to_vertex, edge_ref);
+  CreateAndLinkDelta(&transaction_, new_to_vertex, Delta::RemoveInEdgeTag(), edge_type, from_vertex, edge_ref);
+  new_to_vertex->in_edges.emplace_back(edge_type, from_vertex, edge_ref);
+
+  transaction_.manyDeltasCache.Invalidate(from_vertex, edge_type, EdgeDirection::OUT);
+  transaction_.manyDeltasCache.Invalidate(old_to_vertex, edge_type, EdgeDirection::IN);
+  transaction_.manyDeltasCache.Invalidate(new_to_vertex, edge_type, EdgeDirection::IN);
+
+  return EdgeAccessor(edge_ref, edge_type, from_vertex, new_to_vertex, &transaction_, &storage_->indices_,
+                      &storage_->constraints_, config_);
+}
+
 Result<std::optional<EdgeAccessor>> InMemoryStorage::InMemoryAccessor::DeleteEdge(EdgeAccessor *edge) {
   MG_ASSERT(edge->transaction_ == &transaction_,
             "EdgeAccessor must be from the same transaction as the storage "
             "accessor when deleting an edge!");
-  auto edge_ref = edge->edge_;
-  auto edge_type = edge->edge_type_;
+  auto &edge_ref = edge->edge_;
+  auto &edge_type = edge->edge_type_;
 
   std::unique_lock<utils::RWSpinLock> guard;
   if (config_.properties_on_edges) {

src/storage/v2/inmemory/storage.hpp

@@ -221,6 +221,10 @@ class InMemoryStorage final : public Storage {
     /// @throw std::bad_alloc
     Result<EdgeAccessor> CreateEdge(VertexAccessor *from, VertexAccessor *to, EdgeTypeId edge_type) override;
 
+    Result<EdgeAccessor> EdgeSetFrom(EdgeAccessor *edge, VertexAccessor *new_from) override;
+
+    Result<EdgeAccessor> EdgeSetTo(EdgeAccessor *edge, VertexAccessor *new_to) override;
+
     /// Accessor to the deleted edge if a deletion took place, std::nullopt otherwise
     /// @throw std::bad_alloc
     Result<std::optional<EdgeAccessor>> DeleteEdge(EdgeAccessor *edge) override;

src/storage/v2/storage.hpp

@@ -153,6 +153,10 @@ class Storage {
 
     virtual Result<EdgeAccessor> CreateEdge(VertexAccessor *from, VertexAccessor *to, EdgeTypeId edge_type) = 0;
 
+    virtual Result<EdgeAccessor> EdgeSetFrom(EdgeAccessor *edge, VertexAccessor *new_from) = 0;
+
+    virtual Result<EdgeAccessor> EdgeSetTo(EdgeAccessor *edge, VertexAccessor *new_to) = 0;
+
     virtual Result<std::optional<EdgeAccessor>> DeleteEdge(EdgeAccessor *edge) = 0;
 
     virtual bool LabelIndexExists(LabelId label) const = 0;

tests/e2e/CMakeLists.txt

@@ -64,6 +64,7 @@ add_subdirectory(batched_procedures)
 add_subdirectory(import_mode)
 add_subdirectory(concurrent_query_modules)
 add_subdirectory(set_properties)
+add_subdirectory(transaction_rollback)
 
 copy_e2e_python_files(pytest_runner pytest_runner.sh "")
 file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/memgraph-selfsigned.crt DESTINATION ${CMAKE_CURRENT_BINARY_DIR})

tests/e2e/transaction_rollback/CMakeLists.txt

@@ -0,0 +1,9 @@
+function(transaction_rollback_e2e_python_files FILE_NAME)
+    copy_e2e_python_files(transaction_abort ${FILE_NAME})
+endfunction()
+
+transaction_rollback_e2e_python_files(common.py)
+transaction_rollback_e2e_python_files(conftest.py)
+transaction_rollback_e2e_python_files(transaction.py)
+
+add_subdirectory(procedures)

tests/e2e/transaction_rollback/common.py

@@ -0,0 +1,25 @@
+# Copyright 2023 Memgraph Ltd.
+#
+# Use of this software is governed by the Business Source License
+# included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+# License, and you may not use this file except in compliance with the Business Source License.
+#
+# As of the Change Date specified in that file, in accordance with
+# the Business Source License, use of this software will be governed
+# by the Apache License, Version 2.0, included in the file
+# licenses/APL.txt.
+
+import typing
+
+import mgclient
+
+
+def execute_and_fetch_all(cursor: mgclient.Cursor, query: str, params: dict = {}) -> typing.List[tuple]:
+    cursor.execute(query, params)
+    return cursor.fetchall()
+
+
+def connect(**kwargs) -> mgclient.Connection:
+    connection = mgclient.connect(host="localhost", port=7687, **kwargs)
+    connection.autocommit = False
+    return connection

tests/e2e/transaction_rollback/conftest.py

@@ -0,0 +1,21 @@
+# Copyright 2023 Memgraph Ltd.
+#
+# Use of this software is governed by the Business Source License
+# included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+# License, and you may not use this file except in compliance with the Business Source License.
+#
+# As of the Change Date specified in that file, in accordance with
+# the Business Source License, use of this software will be governed
+# by the Apache License, Version 2.0, included in the file
+# licenses/APL.txt.
+
+import pytest
+from common import connect, execute_and_fetch_all
+
+
+@pytest.fixture(autouse=True)
+def connection():
+    connection = connect()
+    yield connection
+    cursor = connection.cursor()
+    execute_and_fetch_all(cursor, "MATCH (n) DETACH DELETE n")

tests/e2e/transaction_rollback/procedures/CMakeLists.txt

@@ -0,0 +1 @@
+add_query_module(transaction_rollback procedures.cpp)

tests/e2e/transaction_rollback/procedures/procedures.cpp

@@ -0,0 +1,76 @@
+// Copyright 2023 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "mg_procedure.h"
+
+#include "mgp.hpp"
+
+namespace {
+
+constexpr std::string_view ProcedureFrom = "set_from";
+constexpr std::string_view ProcedureTo = "set_to";
+
+void SetFrom(mgp_list *args, mgp_graph *memgraph_graph, mgp_result *result, mgp_memory *memory) {
+  mgp::MemoryDispatcherGuard guard(memory);
+  const auto arguments = mgp::List(args);
+  try {
+    auto rel = arguments[0].ValueRelationship();
+    auto new_from = arguments[0].ValueNode();
+    mgp::Graph graph{memgraph_graph};
+    graph.SetFrom(rel, new_from);
+  } catch (const std::exception &e) {
+    return;
+  }
+}
+
+void SetTo(mgp_list *args, mgp_graph *memgraph_graph, mgp_result *result, mgp_memory *memory) {
+  mgp::MemoryDispatcherGuard guard(memory);
+  const auto arguments = mgp::List(args);
+  try {
+    auto rel = arguments[0].ValueRelationship();
+    auto new_to = arguments[0].ValueNode();
+    mgp::Graph graph{memgraph_graph};
+    graph.SetTo(rel, new_to);
+  } catch (const std::exception &e) {
+    return;
+  }
+}
+
+}  // namespace
+
+// Each module needs to define mgp_init_module function.
+// Here you can register multiple functions/procedures your module supports.
+extern "C" int mgp_init_module(struct mgp_module *module, struct mgp_memory *memory) {
+  {
+    try {
+      mgp::MemoryDispatcherGuard guard(memory);
+
+      mgp::AddProcedure(
+          SetFrom, ProcedureFrom, mgp::ProcedureType::Write,
+          {mgp::Parameter("relationship", mgp::Type::Relationship), mgp::Parameter("node_from", mgp::Type::Node)}, {},
+          module, memory);
+      mgp::AddProcedure(
+          SetTo, ProcedureTo, mgp::ProcedureType::Write,
+          {mgp::Parameter("relationship", mgp::Type::Relationship), mgp::Parameter("node_to", mgp::Type::Node)}, {},
+          module, memory);
+
+    } catch (const std::exception &e) {
+      return 1;
+    }
+  }
+
+  return 0;
+}
+
+// This is an optional function if you need to release any resources before the
+// module is unloaded. You will probably need this if you acquired some
+// resources in mgp_init_module.
+extern "C" int mgp_shutdown_module() { return 0; }

tests/e2e/transaction_rollback/transaction.py

@@ -0,0 +1,58 @@
+# Copyright 2023 Memgraph Ltd.
+#
+# Use of this software is governed by the Business Source License
+# included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+# License, and you may not use this file except in compliance with the Business Source License.
+#
+# As of the Change Date specified in that file, in accordance with
+# the Business Source License, use of this software will be governed
+# by the Apache License, Version 2.0, included in the file
+# licenses/APL.txt.
+
+import sys
+
+import pytest
+from common import execute_and_fetch_all
+
+
+def test_change_from_rollback(connection):
+    cursor = connection.cursor()
+
+    execute_and_fetch_all(cursor, "MATCH (n) DETACH DELETE n;")
+    execute_and_fetch_all(cursor, "CREATE (n:Node1) CREATE (m:Node2) CREATE (k:Node3) CREATE (n)-[:Relationship]->(m);")
+    connection.commit()
+
+    execute_and_fetch_all(
+        cursor,
+        "MATCH (n:Node1)-[r:Relationship]->(m:Node2) MATCH (k:Node3) CALL transaction_rollback.set_from(r, k);",
+    )
+    connection.rollback()
+
+    result = list(execute_and_fetch_all(cursor, f"MATCH (n)-[r]->(m) RETURN n, r, m"))
+    assert len(result) == 1
+    node_from, rel, node_to = result[0]
+    assert list(node_from.labels)[0] == "Node1"
+    assert list(node_to.labels)[0] == "Node2"
+
+
+def test_change_to_rollback(connection):
+    cursor = connection.cursor()
+
+    execute_and_fetch_all(cursor, "MATCH (n) DETACH DELETE n;")
+    execute_and_fetch_all(cursor, "CREATE (n:Node1) CREATE (m:Node2) CREATE (k:Node3) CREATE (n)-[:Relationship]->(m);")
+    connection.commit()
+
+    execute_and_fetch_all(
+        cursor, "MATCH (n:Node1)-[r:Relationship]->(m:Node2) MATCH (k:Node3) CALL transaction_rollback.set_to(r, k);"
+    )
+    connection.rollback()
+
+    result = list(execute_and_fetch_all(cursor, f"MATCH (n)-[r]->(m) RETURN n, r, m"))
+    assert len(result) == 1
+    node_from, rel, node_to = result[0]
+    assert list(node_from.labels)[0] == "Node1"
+    assert list(node_to.labels)[0] == "Node2"
+
+
+if __name__ == "__main__":
+    sys.exit(pytest.main([__file__, "-rA"]))

tests/e2e/transaction_rollback/workloads.yaml

@@ -0,0 +1,19 @@
+args: &args
+  - "--bolt-port"
+  - "7687"
+  - "--log-level=TRACE"
+
+in_memory_cluster: &in_memory_cluster
+  cluster:
+    main:
+      args: *args
+      log_file: "transaction-rollback-e2e.log"
+      setup_queries: []
+      validation_queries: []
+
+workloads:
+  - name: "Transaction rollback"
+    binary: "tests/e2e/pytest_runner.sh"
+    proc: "tests/e2e/transaction_rollback/procedures/"
+    args: ["transaction_rollback/transaction.py"]
+    <<: *in_memory_cluster

tests/unit/cpp_api.cpp

@@ -690,6 +690,50 @@ TYPED_TEST(CppApiTestFixture, TestValueToString) {
       "{key: node_property, key2: node_property2})-[type: Loves2, id: 1, properties: {}]->(id: 4, properties: {})");
 }
 
+TYPED_TEST(CppApiTestFixture, TestRelationshipChangeFrom) {
+  if (std::is_same<TypeParam, memgraph::storage::DiskStorage>::value) {
+    return;
+  }
+
+  mgp_graph raw_graph = this->CreateGraph();
+  auto graph = mgp::Graph(&raw_graph);
+
+  auto node_1 = graph.CreateNode();
+  auto node_2 = graph.CreateNode();
+  auto node_3 = graph.CreateNode();
+
+  auto relationship = graph.CreateRelationship(node_1, node_2, "Edge");
+
+  ASSERT_EQ(relationship.From().Id(), node_1.Id());
+  graph.SetFrom(relationship, node_3);
+
+  ASSERT_EQ(std::string(relationship.Type()), "Edge");
+  ASSERT_EQ(relationship.From().Id(), node_3.Id());
+  ASSERT_EQ(relationship.To().Id(), node_2.Id());
+}
+
+TYPED_TEST(CppApiTestFixture, TestRelationshipChangeTo) {
+  if (std::is_same<TypeParam, memgraph::storage::DiskStorage>::value) {
+    return;
+  }
+
+  mgp_graph raw_graph = this->CreateGraph();
+  auto graph = mgp::Graph(&raw_graph);
+
+  auto node_1 = graph.CreateNode();
+  auto node_2 = graph.CreateNode();
+  auto node_3 = graph.CreateNode();
+
+  auto relationship = graph.CreateRelationship(node_1, node_2, "Edge");
+
+  ASSERT_EQ(relationship.To().Id(), node_2.Id());
+  graph.SetTo(relationship, node_3);
+
+  ASSERT_EQ(std::string(relationship.Type()), "Edge");
+  ASSERT_EQ(relationship.From().Id(), node_1.Id());
+  ASSERT_EQ(relationship.To().Id(), node_3.Id());
+}
+
 TYPED_TEST(CppApiTestFixture, TestInAndOutDegrees) {
   mgp_graph raw_graph = this->CreateGraph(memgraph::storage::View::NEW);
   auto graph = mgp::Graph(&raw_graph);