replace std::unordered_map with robin_hood in find path executor

src/graph/executor/algo/BatchShortestPath.cpp

@@ -348,7 +348,7 @@ folly::Future<bool> BatchShortestPath::conjunctPath(size_t rowNum, bool oddStep)
     if (vertices.empty()) {
       return false;
     }
-    std::unordered_map<Value, Value> verticesMap;
+    robin_hood::unordered_flat_map<Value, Value, std::hash<Value>> verticesMap;
     for (auto& vertex : vertices) {
       verticesMap[vertex.getVertex().vid] = std::move(vertex);
     }

src/graph/executor/algo/BatchShortestPath.h

@@ -21,7 +21,10 @@ class BatchShortestPath final : public ShortestPathBase {
                                 DataSet* result) override;
 
   using CustomPath = Row;
-  using PathMap = std::unordered_map<DstVid, std::unordered_map<StartVid, std::vector<CustomPath>>>;
+  using PathMap = robin_hood::unordered_flat_map<
+      DstVid,
+      robin_hood::unordered_flat_map<StartVid, std::vector<CustomPath>, std::hash<StartVid>>,
+      std::hash<DstVid>>;
 
  private:
   size_t splitTask(const HashSet& startVids, const HashSet& endVids);

src/graph/executor/algo/MultiShortestPathExecutor.h

@@ -5,7 +5,10 @@
 #ifndef GRAPH_EXECUTOR_ALGO_MULTISHORTESTPATHEXECUTOR_H_
 #define GRAPH_EXECUTOR_ALGO_MULTISHORTESTPATHEXECUTOR_H_
 
+#include <robin_hood.h>
+
 #include "graph/executor/Executor.h"
+
 // MultiShortestPath has two inputs.  GetNeighbors(From) & GetNeighbors(To)
 // There are two Main functions
 // First : Get the next vid for GetNeighbors to expand
@@ -58,7 +61,10 @@ class MultiShortestPathExecutor final : public Executor {
 
  private:
   // key: dst, value: {key : src, value: paths}
-  using Interims = std::unordered_map<Value, std::unordered_map<Value, std::vector<Path>>>;
+  using Interims = robin_hood::unordered_flat_map<
+      Value,
+      robin_hood::unordered_flat_map<Value, std::vector<Path>, std::hash<Value>>,
+      std::hash<Value>>;
 
   void init();
   std::vector<Path> createPaths(const std::vector<Path>& paths, const Edge& edge);

src/graph/executor/algo/ProduceAllPathsExecutor.h

@@ -5,6 +5,8 @@
 #ifndef GRAPH_EXECUTOR_ALGO_PRODUCEALLPATHSEXECUTOR_H_
 #define GRAPH_EXECUTOR_ALGO_PRODUCEALLPATHSEXECUTOR_H_
 
+#include <robin_hood.h>
+
 #include "graph/executor/Executor.h"
 
 // ProduceAllPath has two inputs.  GetNeighbors(From) & GetNeighbors(To)
@@ -52,7 +54,7 @@ class ProduceAllPathsExecutor final : public Executor {
 
  private:
   // k: dst, v: paths to dst
-  using Interims = std::unordered_map<Value, std::vector<Path>>;
+  using Interims = robin_hood::unordered_flat_map<Value, std::vector<Path>, std::hash<Value>>;
 
   Status buildPath(bool reverse);
   folly::Future<Status> conjunctPath();

src/graph/executor/algo/SingleShortestPath.cpp

@@ -47,7 +47,7 @@ void SingleShortestPath::init(const HashSet& startVids, const HashSet& endVids,
   resultDs_.resize(rowSize);
   for (const auto& startVid : startVids) {
     for (const auto& endVid : endVids) {
-      std::unordered_map<Value, std::vector<Row>> steps;
+      robin_hood::unordered_flat_map<Value, std::vector<Row>, std::hash<Value>> steps;
       std::vector<Row> dummy;
       steps.emplace(endVid, std::move(dummy));
       HalfPath originRightPath({std::move(steps)});

src/graph/executor/algo/SingleShortestPath.h

@@ -21,7 +21,8 @@ class SingleShortestPath final : public ShortestPathBase {
                                 const HashSet& endVids,
                                 DataSet* result) override;
 
-  using HalfPath = std::vector<std::unordered_map<DstVid, std::vector<CustomStep>>>;
+  using HalfPath = std::vector<
+      robin_hood::unordered_flat_map<DstVid, std::vector<CustomStep>, std::hash<Value>>>;
 
  private:
   void init(const HashSet& startVids, const HashSet& endVids, size_t rowSize);

src/graph/executor/algo/SubgraphExecutor.cpp

@@ -27,7 +27,7 @@ folly::Future<Status> SubgraphExecutor::execute() {
   ResultBuilder builder;
   builder.value(iter->valuePtr());
 
-  std::unordered_map<Value, int64_t> currentVids;
+  robin_hood::unordered_flat_map<Value, int64_t, std::hash<Value>> currentVids;
   currentVids.reserve(gnSize);
   historyVids_.reserve(historyVids_.size() + gnSize);
   if (currentStep == 1) {

src/graph/executor/algo/SubgraphExecutor.h

@@ -5,6 +5,8 @@
 #ifndef GRAPH_EXECUTOR_ALGO_SUBGRAPHEXECUTOR_H_
 #define GRAPH_EXECUTOR_ALGO_SUBGRAPHEXECUTOR_H_
 
+#include <robin_hood.h>
+
 #include "graph/executor/Executor.h"
 
 // Subgraph receive result from GetNeighbors
@@ -45,7 +47,7 @@ class SubgraphExecutor : public Executor {
   folly::Future<Status> execute() override;
 
  private:
-  std::unordered_map<Value, int64_t> historyVids_;
+  robin_hood::unordered_flat_map<Value, int64_t, std::hash<Value>> historyVids_;
 };
 
 }  // namespace graph