Fix remote pull

Summary:
- Extracted TypedValue reconstruction into utils (will need that soon)
- Added more error handling in RemotePull

Reviewers: teon.banek, msantl

Reviewed By: teon.banek

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D1183

src/distributed/remote_produce_rpc_server.hpp

@@ -12,6 +12,7 @@
 #include "distributed/plan_consumer.hpp"
 #include "distributed/remote_pull_produce_rpc_messages.hpp"
 #include "query/context.hpp"
+#include "query/exceptions.hpp"
 #include "query/frontend/semantic/symbol_table.hpp"
 #include "query/interpret/frame.hpp"
 #include "query/parameters.hpp"
@@ -47,16 +48,30 @@ class RemoteProduceRpcServer {
     /** Returns a vector of typed values (one for each `pull_symbol`), and a
      * `bool` indicating if the pull was successful (or the cursor is
      * exhausted). */
-    std::pair<std::vector<query::TypedValue>, bool> Pull() {
+    std::pair<std::vector<query::TypedValue>, RemotePullState> Pull() {
+      RemotePullState state = RemotePullState::CURSOR_IN_PROGRESS;
       std::vector<query::TypedValue> results;
-      auto success = cursor_->Pull(frame_, context_);
+      try {
-      if (success) {
+        if (cursor_->Pull(frame_, context_)) {
           results.reserve(pull_symbols_.size());
           for (const auto &symbol : pull_symbols_) {
             results.emplace_back(std::move(frame_[symbol]));
           }
+        } else {
+          state = RemotePullState::CURSOR_EXHAUSTED;
         }
-      return std::make_pair(std::move(results), success);
+      } catch (const mvcc::SerializationError &) {
+        state = RemotePullState::SERIALIZATION_ERROR;
+      } catch (const LockTimeoutException &) {
+        state = RemotePullState::LOCK_TIMEOUT_ERROR;
+      } catch (const RecordDeletedError &) {
+        state = RemotePullState::UPDATE_DELETED_ERROR;
+      } catch (const query::ReconstructionException &) {
+        state = RemotePullState::RECONSTRUCTION_ERROR;
+      } catch (const query::QueryRuntimeException &) {
+        state = RemotePullState::QUERY_ERROR;
+      }
+      return std::make_pair(std::move(results), state);
     }
 
    private:
@@ -123,17 +138,13 @@ class RemoteProduceRpcServer {
     auto &ongoing_produce = GetOngoingProduce(req);
 
     RemotePullResData result{db_.WorkerId(), req.send_old, req.send_new};
-
     result.state_and_frames.pull_state = RemotePullState::CURSOR_IN_PROGRESS;
 
     for (int i = 0; i < req.batch_size; ++i) {
-      // TODO exception handling (Serialization errors)
-      // when full CRUD. Maybe put it in OngoingProduce::Pull
       auto pull_result = ongoing_produce.Pull();
-      if (!pull_result.second) {
+      result.state_and_frames.pull_state = pull_result.second;
-        result.state_and_frames.pull_state = RemotePullState::CURSOR_EXHAUSTED;
+      if (pull_result.second != RemotePullState::CURSOR_IN_PROGRESS)
         break;
-      }
       result.state_and_frames.frames.emplace_back(std::move(pull_result.first));
     }
 

src/distributed/remote_pull_produce_rpc_messages.hpp

@@ -26,8 +26,11 @@ constexpr int kDefaultBatchSize = 20;
 enum class RemotePullState {
   CURSOR_EXHAUSTED,
   CURSOR_IN_PROGRESS,
-  SERIALIZATION_ERROR  // future-proofing for full CRUD
+  SERIALIZATION_ERROR,
-                       // TODO in full CRUD other errors
+  LOCK_TIMEOUT_ERROR,
+  UPDATE_DELETED_ERROR,
+  RECONSTRUCTION_ERROR,
+  QUERY_ERROR
 };
 
 const std::string kRemotePullProduceRpcName = "RemotePullProduceRpc";

src/query/common.cpp

@@ -180,4 +180,37 @@ std::string ParseParameter(const std::string &s) {
   }
   return out;
 }
+
+void ReconstructTypedValue(TypedValue &value) {
+  using Type = TypedValue::Type;
+  switch (value.type()) {
+    case Type::Vertex:
+      if (!value.ValueVertex().Reconstruct()) throw ReconstructionException();
+      break;
+    case Type::Edge:
+      if (!value.ValueEdge().Reconstruct()) throw ReconstructionException();
+      break;
+    case Type::List:
+      for (TypedValue &inner_value : value.Value<std::vector<TypedValue>>())
+        ReconstructTypedValue(inner_value);
+      break;
+    case Type::Map:
+      for (auto &kv : value.Value<std::map<std::string, TypedValue>>())
+        ReconstructTypedValue(kv.second);
+      break;
+    case Type::Path:
+      for (auto &vertex : value.ValuePath().vertices()) {
+        if (!vertex.Reconstruct()) throw ReconstructionException();
+      }
+      for (auto &edge : value.ValuePath().edges()) {
+        if (!edge.Reconstruct()) throw ReconstructionException();
+      }
+    case Type::Null:
+    case Type::Bool:
+    case Type::Int:
+    case Type::Double:
+    case Type::String:
+      break;
+  }
+}
 }  // namespace query

src/query/common.hpp

@@ -3,6 +3,8 @@
 #include <cstdint>
 #include <string>
 
+#include "query/typed_value.hpp"
+
 namespace query {
 
 // These are the functions for parsing literals and parameter names from
@@ -23,4 +25,12 @@ std::string ParseParameter(const std::string &s);
  * by some previous part of execution.
  */
 enum class GraphView { AS_IS, OLD, NEW };
+
+/**
+ * Helper function for recursively reconstructing all the accessors in the
+ * given TypedValue.
+ *
+ * @returns - If the reconstruction succeeded.
+ */
+void ReconstructTypedValue(TypedValue &value);
 }

src/query/exceptions.hpp

@@ -99,4 +99,12 @@ class HintedAbortError : public utils::BasicException {
             "--query-execution-time-sec flag") {}
 };
 
+class ReconstructionException : public QueryException {
+ public:
+  ReconstructionException()
+      : QueryException(
+            "Record invalid after WITH clause. Most likely deleted by a "
+            "preceeding DELETE.") {}
+};
+
 }  // namespace query

src/query/plan/operator.cpp

@@ -19,6 +19,7 @@
 #include "query/frontend/semantic/symbol_table.hpp"
 #include "query/interpret/eval.hpp"
 #include "query/path.hpp"
+#include "utils/exceptions.hpp"
 
 // macro for the default implementation of LogicalOperator::Accept
 // that accepts the visitor and visits it's input_ operator
@@ -1618,47 +1619,6 @@ void ExpandUniquenessFilter<TAccessor>::ExpandUniquenessFilterCursor::Reset() {
 template class ExpandUniquenessFilter<VertexAccessor>;
 template class ExpandUniquenessFilter<EdgeAccessor>;
 
-namespace {
-
-/**
- * Helper function for recursively reconstructing all the accessors in the
- * given TypedValue.
- */
-void ReconstructTypedValue(TypedValue &value) {
-  const static std::string vertex_error_msg =
-      "Vertex invalid after WITH clause, (most likely deleted by a "
-      "preceeding DELETE clause)";
-  const static std::string edge_error_msg =
-      "Edge invalid after WITH clause, (most likely deleted by a "
-      "preceeding DELETE clause)";
-  switch (value.type()) {
-    case TypedValue::Type::Vertex:
-      if (!value.Value<VertexAccessor>().Reconstruct())
-        throw QueryRuntimeException(vertex_error_msg);
-      break;
-    case TypedValue::Type::Edge:
-      if (!value.Value<EdgeAccessor>().Reconstruct())
-        throw QueryRuntimeException(edge_error_msg);
-      break;
-    case TypedValue::Type::List:
-      for (TypedValue &inner_value : value.Value<std::vector<TypedValue>>())
-        ReconstructTypedValue(inner_value);
-      break;
-    case TypedValue::Type::Map:
-      for (auto &kv : value.Value<std::map<std::string, TypedValue>>())
-        ReconstructTypedValue(kv.second);
-      break;
-    case TypedValue::Type::Path:
-      for (auto &vertex : value.ValuePath().vertices())
-        if (vertex.Reconstruct()) throw QueryRuntimeException(vertex_error_msg);
-      for (auto &edge : value.ValuePath().edges())
-        if (edge.Reconstruct()) throw QueryRuntimeException(edge_error_msg);
-    default:
-      break;
-  }
-}
-}  // namespace
-
 Accumulate::Accumulate(const std::shared_ptr<LogicalOperator> &input,
                        const std::vector<Symbol> &symbols, bool advance_command)
     : input_(input), symbols_(symbols), advance_command_(advance_command) {}
@@ -1690,7 +1650,7 @@ bool Accumulate::AccumulateCursor::Pull(Frame &frame, Context &context) {
     if (self_.advance_command_) {
       db_.AdvanceCommand();
       for (auto &row : cache_)
-        for (auto &col : row) ReconstructTypedValue(col);
+        for (auto &col : row) query::ReconstructTypedValue(col);
     }
   }
 
@@ -2633,7 +2593,20 @@ bool PullRemote::PullRemoteCursor::Pull(Frame &frame, Context &context) {
           EndRemotePull();
           throw mvcc::SerializationError(
               "Serialization error occured during PullRemote !");
-          break;
+        case distributed::RemotePullState::LOCK_TIMEOUT_ERROR:
+          EndRemotePull();
+          throw LockTimeoutException(
+              "LockTimeout error occured during PullRemote !");
+        case distributed::RemotePullState::UPDATE_DELETED_ERROR:
+          EndRemotePull();
+          throw RecordDeletedError();
+        case distributed::RemotePullState::RECONSTRUCTION_ERROR:
+          EndRemotePull();
+          throw query::ReconstructionException();
+        case distributed::RemotePullState::QUERY_ERROR:
+          EndRemotePull();
+          throw QueryRuntimeException(
+              "Query runtime error occurred duing PullRemote !");
       }
     }
 

tests/unit/query_plan_create_set_remove_delete.cpp

@@ -452,7 +452,7 @@ TEST(QueryPlan, DeleteAdvance) {
       n.op_, std::vector<Expression *>{n_get}, false);
   auto advance = std::make_shared<Accumulate>(
       delete_op, std::vector<Symbol>{n.sym_}, true);
-  EXPECT_THROW(PullAll(advance, dba, symbol_table), QueryRuntimeException);
+  EXPECT_THROW(PullAll(advance, dba, symbol_table), ReconstructionException);
 }
 
 TEST(QueryPlan, SetProperty) {