!1977 random walk in gnn node2vec

Merge pull request !1977 from JonathanY/randomwalk

example/graph_to_mindrecord/sns/mr_api.py

+# Copyright 2020 Huawei Technologies Co., Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+"""
+User-defined API for MindRecord GNN writer.
+"""
+social_data = [[348, 350], [348, 327], [348, 329], [348, 331], [348, 335],
+               [348, 336], [348, 337], [348, 338], [348, 340], [348, 341],
+               [348, 342], [348, 343], [348, 344], [348, 345], [348, 346],
+               [348, 347], [347, 351], [347, 327], [347, 329], [347, 331],
+               [347, 335], [347, 341], [347, 345], [347, 346], [346, 335],
+               [346, 340], [346, 339], [346, 349], [346, 353], [346, 354],
+               [346, 341], [346, 345], [345, 335], [345, 336], [345, 341],
+               [344, 338], [344, 342], [343, 332], [343, 338], [343, 342],
+               [342, 332], [340, 349], [334, 349], [333, 349], [330, 349],
+               [328, 349], [359, 349], [358, 352], [358, 349], [358, 354],
+               [358, 356], [357, 350], [357, 354], [357, 356], [356, 350],
+               [355, 352], [353, 350], [352, 349], [351, 349], [350, 349]]
+
+# profile:  (num_features, feature_data_types, feature_shapes)
+node_profile = (0, [], [])
+edge_profile = (0, [], [])
+
+
+def yield_nodes(task_id=0):
+    """
+    Generate node data
+
+    Yields:
+        data (dict): data row which is dict.
+    """
+    print("Node task is {}".format(task_id))
+    node_list = []
+    for edge in social_data:
+        src, dst = edge
+        if src not in node_list:
+            node_list.append(src)
+        if dst not in node_list:
+            node_list.append(dst)
+    node_list.sort()
+    print(node_list)
+    for node_id in node_list:
+        node = {'id': node_id, 'type': 1}
+        yield node
+
+
+def yield_edges(task_id=0):
+    """
+    Generate edge data
+
+    Yields:
+        data (dict): data row which is dict.
+    """
+    print("Edge task is {}".format(task_id))
+    line_count = 0
+    for undirected_edge in social_data:
+        line_count += 1
+        edge = {
+            'id': line_count,
+            'src_id': undirected_edge[0],
+            'dst_id': undirected_edge[1],
+            'type': 1}
+        yield edge
+        line_count += 1
+        edge = {
+            'id': line_count,
+            'src_id': undirected_edge[1],
+            'dst_id': undirected_edge[0],
+            'type': 1}
+        yield edge

example/graph_to_mindrecord/write_sns.sh

+#!/bin/bash
+MINDRECORD_PATH=/tmp/sns
+
+rm -f $MINDRECORD_PATH/*
+
+python writer.py --mindrecord_script sns \
+--mindrecord_file "$MINDRECORD_PATH/sns" \
+--mindrecord_partitions 1 \
+--mindrecord_header_size_by_bit 14 \
+--mindrecord_page_size_by_bit 15

mindspore/ccsrc/dataset/api/python_bindings.cc

@@ -656,9 +656,16 @@ void bindGraphData(py::module *m) {
            THROW_IF_ERROR(g.GetNodeFeature(node_list, feature_types, &out));
            return out.getRow();
          })
-    .def("graph_info", [](gnn::Graph &g) {
-      py::dict out;
-      THROW_IF_ERROR(g.GraphInfo(&out));
+    .def("graph_info",
+         [](gnn::Graph &g) {
+           py::dict out;
+           THROW_IF_ERROR(g.GraphInfo(&out));
+           return out;
+         })
+    .def("random_walk", [](gnn::Graph &g, std::vector<gnn::NodeIdType> node_list, std::vector<gnn::NodeType> meta_path,
+                           float step_home_param, float step_away_param, gnn::NodeIdType default_node) {
+      std::shared_ptr<Tensor> out;
+      THROW_IF_ERROR(g.RandomWalk(node_list, meta_path, step_home_param, step_away_param, default_node, &out));
       return out;
     });
 }

mindspore/ccsrc/dataset/engine/gnn/graph.cc

@@ -29,7 +29,7 @@ namespace dataset {
 namespace gnn {
 
 Graph::Graph(std::string dataset_file, int32_t num_workers)
-    : dataset_file_(dataset_file), num_workers_(num_workers), rnd_(GetRandomDevice()) {
+    : dataset_file_(dataset_file), num_workers_(num_workers), rnd_(GetRandomDevice()), random_walk_(this) {
   rnd_.seed(GetSeed());
   MS_LOG(INFO) << "num_workers:" << num_workers;
 }
@@ -240,8 +240,13 @@ Status Graph::GetNegSampledNeighbors(const std::vector<NodeIdType> &node_list, N
   return Status::OK();
 }
 
-Status Graph::RandomWalk(const std::vector<NodeIdType> &node_list, const std::vector<NodeType> &meta_path, float p,
-                         float q, NodeIdType default_node, std::shared_ptr<Tensor> *out) {
+Status Graph::RandomWalk(const std::vector<NodeIdType> &node_list, const std::vector<NodeType> &meta_path,
+                         float step_home_param, float step_away_param, NodeIdType default_node,
+                         std::shared_ptr<Tensor> *out) {
+  RETURN_IF_NOT_OK(random_walk_.Build(node_list, meta_path, step_home_param, step_away_param, default_node));
+  std::vector<std::vector<NodeIdType>> walks;
+  RETURN_IF_NOT_OK(random_walk_.SimulateWalk(&walks));
+  RETURN_IF_NOT_OK(CreateTensorByVector<NodeIdType>({walks}, DataType(DataType::DE_INT32), out));
   return Status::OK();
 }
 
@@ -386,6 +391,195 @@ Status Graph::GetNodeByNodeId(NodeIdType id, std::shared_ptr<Node> *node) {
   return Status::OK();
 }
 
+Graph::RandomWalkBase::RandomWalkBase(Graph *graph)
+    : graph_(graph), step_home_param_(1.0), step_away_param_(1.0), default_node_(-1), num_walks_(1), num_workers_(1) {}
+
+Status Graph::RandomWalkBase::Build(const std::vector<NodeIdType> &node_list, const std::vector<NodeType> &meta_path,
+                                    float step_home_param, float step_away_param, const NodeIdType default_node,
+                                    int32_t num_walks, int32_t num_workers) {
+  node_list_ = node_list;
+  if (meta_path.empty() || meta_path.size() > kMaxNumWalks) {
+    std::string err_msg = "Failed, meta path required between 1 and " + std::to_string(kMaxNumWalks) +
+                          ". The size of input path is " + std::to_string(meta_path.size());
+    RETURN_STATUS_UNEXPECTED(err_msg);
+  }
+  meta_path_ = meta_path;
+  if (step_home_param < kGnnEpsilon || step_away_param < kGnnEpsilon) {
+    std::string err_msg = "Failed, step_home_param and step_away_param required greater than " +
+                          std::to_string(kGnnEpsilon) + ". step_home_param: " + std::to_string(step_home_param) +
+                          ", step_away_param: " + std::to_string(step_away_param);
+    RETURN_STATUS_UNEXPECTED(err_msg);
+  }
+  step_home_param_ = step_home_param;
+  step_away_param_ = step_away_param;
+  default_node_ = default_node;
+  num_walks_ = num_walks;
+  num_workers_ = num_workers;
+  return Status::OK();
+}
+
+Status Graph::RandomWalkBase::Node2vecWalk(const NodeIdType &start_node, std::vector<NodeIdType> *walk_path) {
+  // Simulate a random walk starting from start node.
+  auto walk = std::vector<NodeIdType>(1, start_node);  // walk is an vector
+  // walk simulate
+  while (walk.size() - 1 < meta_path_.size()) {
+    // current nodE
+    auto cur_node_id = walk.back();
+    std::shared_ptr<Node> cur_node;
+    RETURN_IF_NOT_OK(graph_->GetNodeByNodeId(cur_node_id, &cur_node));
+
+    // current neighbors
+    std::vector<NodeIdType> cur_neighbors;
+    RETURN_IF_NOT_OK(cur_node->GetAllNeighbors(meta_path_[walk.size() - 1], &cur_neighbors, true));
+    std::sort(cur_neighbors.begin(), cur_neighbors.end());
+
+    // break if no neighbors
+    if (cur_neighbors.empty()) {
+      break;
+    }
+
+    // walk by the fist node, then by the previous 2 nodes
+    std::shared_ptr<StochasticIndex> stochastic_index;
+    if (walk.size() == 1) {
+      RETURN_IF_NOT_OK(GetNodeProbability(cur_node_id, meta_path_[0], &stochastic_index));
+    } else {
+      NodeIdType prev_node_id = walk[walk.size() - 2];
+      RETURN_IF_NOT_OK(GetEdgeProbability(prev_node_id, cur_node_id, walk.size() - 2, &stochastic_index));
+    }
+    NodeIdType next_node_id = cur_neighbors[WalkToNextNode(*stochastic_index)];
+    walk.push_back(next_node_id);
+  }
+
+  while (walk.size() - 1 < meta_path_.size()) {
+    walk.push_back(default_node_);
+  }
+
+  *walk_path = std::move(walk);
+  return Status::OK();
+}
+
+Status Graph::RandomWalkBase::SimulateWalk(std::vector<std::vector<NodeIdType>> *walks) {
+  // Repeatedly simulate random walks from each node
+  std::vector<uint32_t> permutation(node_list_.size());
+  std::iota(permutation.begin(), permutation.end(), 0);
+  for (int32_t i = 0; i < num_walks_; i++) {
+    unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
+    std::shuffle(permutation.begin(), permutation.end(), std::default_random_engine(seed));
+    for (const auto &i_perm : permutation) {
+      std::vector<NodeIdType> walk;
+      RETURN_IF_NOT_OK(Node2vecWalk(node_list_[i_perm], &walk));
+      walks->push_back(walk);
+    }
+  }
+  return Status::OK();
+}
+
+Status Graph::RandomWalkBase::GetNodeProbability(const NodeIdType &node_id, const NodeType &node_type,
+                                                 std::shared_ptr<StochasticIndex> *node_probability) {
+  // Generate alias nodes
+  std::shared_ptr<Node> node;
+  graph_->GetNodeByNodeId(node_id, &node);
+  std::vector<NodeIdType> neighbors;
+  RETURN_IF_NOT_OK(node->GetAllNeighbors(node_type, &neighbors, true));
+  std::sort(neighbors.begin(), neighbors.end());
+  auto non_normalized_probability = std::vector<float>(neighbors.size(), 1.0);
+  *node_probability =
+    std::make_shared<StochasticIndex>(GenerateProbability(Normalize<float>(non_normalized_probability)));
+  return Status::OK();
+}
+
+Status Graph::RandomWalkBase::GetEdgeProbability(const NodeIdType &src, const NodeIdType &dst, uint32_t meta_path_index,
+                                                 std::shared_ptr<StochasticIndex> *edge_probability) {
+  // Get the alias edge setup lists for a given edge.
+  std::shared_ptr<Node> src_node;
+  graph_->GetNodeByNodeId(src, &src_node);
+  std::vector<NodeIdType> src_neighbors;
+  RETURN_IF_NOT_OK(src_node->GetAllNeighbors(meta_path_[meta_path_index], &src_neighbors, true));
+
+  std::shared_ptr<Node> dst_node;
+  graph_->GetNodeByNodeId(dst, &dst_node);
+  std::vector<NodeIdType> dst_neighbors;
+  RETURN_IF_NOT_OK(dst_node->GetAllNeighbors(meta_path_[meta_path_index + 1], &dst_neighbors, true));
+
+  std::sort(dst_neighbors.begin(), dst_neighbors.end());
+  std::vector<float> non_normalized_probability;
+  for (const auto &dst_nbr : dst_neighbors) {
+    if (dst_nbr == src) {
+      non_normalized_probability.push_back(1.0 / step_home_param_);  // replace 1.0 with G[dst][dst_nbr]['weight']
+      continue;
+    }
+    auto it = std::find(src_neighbors.begin(), src_neighbors.end(), dst_nbr);
+    if (it != src_neighbors.end()) {
+      // stay close, this node connect both src and dst
+      non_normalized_probability.push_back(1.0);  // replace 1.0 with G[dst][dst_nbr]['weight']
+    } else {
+      // step far away
+      non_normalized_probability.push_back(1.0 / step_away_param_);  // replace 1.0 with G[dst][dst_nbr]['weight']
+    }
+  }
+
+  *edge_probability =
+    std::make_shared<StochasticIndex>(GenerateProbability(Normalize<float>(non_normalized_probability)));
+  return Status::OK();
+}
+
+StochasticIndex Graph::RandomWalkBase::GenerateProbability(const std::vector<float> &probability) {
+  uint32_t K = probability.size();
+  std::vector<int32_t> switch_to_large_index(K, 0);
+  std::vector<float> weight(K, .0);
+  std::vector<int32_t> smaller;
+  std::vector<int32_t> larger;
+  auto random_device = GetRandomDevice();
+  std::uniform_real_distribution<> distribution(-kGnnEpsilon, kGnnEpsilon);
+  float accumulate_threshold = 0.0;
+  for (uint32_t i = 0; i < K; i++) {
+    float threshold_one = distribution(random_device);
+    accumulate_threshold += threshold_one;
+    weight[i] = i < K - 1 ? probability[i] * K + threshold_one : probability[i] * K - accumulate_threshold;
+    weight[i] < 1.0 ? smaller.push_back(i) : larger.push_back(i);
+  }
+
+  while ((!smaller.empty()) && (!larger.empty())) {
+    uint32_t small = smaller.back();
+    smaller.pop_back();
+    uint32_t large = larger.back();
+    larger.pop_back();
+    switch_to_large_index[small] = large;
+    weight[large] = weight[large] + weight[small] - 1.0;
+    weight[large] < 1.0 ? smaller.push_back(large) : larger.push_back(large);
+  }
+  return StochasticIndex(switch_to_large_index, weight);
+}
+
+uint32_t Graph::RandomWalkBase::WalkToNextNode(const StochasticIndex &stochastic_index) {
+  auto switch_to_large_index = stochastic_index.first;
+  auto weight = stochastic_index.second;
+  const uint32_t size_of_index = switch_to_large_index.size();
+
+  auto random_device = GetRandomDevice();
+  std::uniform_real_distribution<> distribution(0.0, 1.0);
+
+  // Generate random integer between [0, K)
+  uint32_t random_idx = std::floor(distribution(random_device) * size_of_index);
+
+  if (distribution(random_device) < weight[random_idx]) {
+    return random_idx;
+  }
+  return switch_to_large_index[random_idx];
+}
+
+template <typename T>
+std::vector<float> Graph::RandomWalkBase::Normalize(const std::vector<T> &non_normalized_probability) {
+  float sum_probability =
+    1.0 * std::accumulate(non_normalized_probability.begin(), non_normalized_probability.end(), 0);
+  if (sum_probability < kGnnEpsilon) {
+    sum_probability = 1.0;
+  }
+  std::vector<float> normalized_probability;
+  std::transform(non_normalized_probability.begin(), non_normalized_probability.end(),
+                 std::back_inserter(normalized_probability), [&](T value) -> float { return value / sum_probability; });
+  return normalized_probability;
+}
 }  // namespace gnn
 }  // namespace dataset
 }  // namespace mindspore

mindspore/ccsrc/dataset/engine/gnn/graph.h

@@ -16,12 +16,14 @@
 #ifndef DATASET_ENGINE_GNN_GRAPH_H_
 #define DATASET_ENGINE_GNN_GRAPH_H_
 
+#include <algorithm>
 #include <memory>
 #include <string>
 #include <map>
 #include <unordered_map>
 #include <unordered_set>
 #include <vector>
+#include <utility>
 
 #include "dataset/core/tensor.h"
 #include "dataset/core/tensor_row.h"
@@ -35,6 +37,10 @@ namespace mindspore {
 namespace dataset {
 namespace gnn {
 
+const float kGnnEpsilon = 0.0001;
+const uint32_t kMaxNumWalks = 80;
+using StochasticIndex = std::pair<std::vector<int32_t>, std::vector<float>>;
+
 struct MetaInfo {
   std::vector<NodeType> node_type;
   std::vector<EdgeType> edge_type;
@@ -99,8 +105,17 @@ class Graph {
   Status GetNegSampledNeighbors(const std::vector<NodeIdType> &node_list, NodeIdType samples_num,
                                 NodeType neg_neighbor_type, std::shared_ptr<Tensor> *out);
 
-  Status RandomWalk(const std::vector<NodeIdType> &node_list, const std::vector<NodeType> &meta_path, float p, float q,
-                    NodeIdType default_node, std::shared_ptr<Tensor> *out);
+  // Node2vec random walk.
+  // @param std::vector<NodeIdType> node_list - List of nodes
+  // @param std::vector<NodeType> meta_path - node type of each step
+  // @param float step_home_param - return hyper parameter in node2vec algorithm
+  // @param float step_away_param - inout hyper parameter in node2vec algorithm
+  // @param NodeIdType default_node - default node id
+  // @param std::shared_ptr<Tensor> *out - Returned nodes id in walk path
+  // @return Status - The error code return
+  Status RandomWalk(const std::vector<NodeIdType> &node_list, const std::vector<NodeType> &meta_path,
+                    float step_home_param, float step_away_param, NodeIdType default_node,
+                    std::shared_ptr<Tensor> *out);
 
   // Get the feature of a node
   // @param std::shared_ptr<Tensor> nodes - List of nodes
@@ -131,6 +146,45 @@ class Graph {
   Status Init();
 
  private:
+  class RandomWalkBase {
+   public:
+    explicit RandomWalkBase(Graph *graph);
+
+    Status Build(const std::vector<NodeIdType> &node_list, const std::vector<NodeType> &meta_path,
+                 float step_home_param = 1.0, float step_away_param = 1.0, NodeIdType default_node = -1,
+                 int32_t num_walks = 1, int32_t num_workers = 1);
+
+    ~RandomWalkBase() = default;
+
+    Status SimulateWalk(std::vector<std::vector<NodeIdType>> *walks);
+
+   private:
+    Status Node2vecWalk(const NodeIdType &start_node, std::vector<NodeIdType> *walk_path);
+
+    Status GetNodeProbability(const NodeIdType &node_id, const NodeType &node_type,
+                              std::shared_ptr<StochasticIndex> *node_probability);
+
+    Status GetEdgeProbability(const NodeIdType &src, const NodeIdType &dst, uint32_t meta_path_index,
+                              std::shared_ptr<StochasticIndex> *edge_probability);
+
+    static StochasticIndex GenerateProbability(const std::vector<float> &probability);
+
+    static uint32_t WalkToNextNode(const StochasticIndex &stochastic_index);
+
+    template <typename T>
+    std::vector<float> Normalize(const std::vector<T> &non_normalized_probability);
+
+    Graph *graph_;
+    std::vector<NodeIdType> node_list_;
+    std::vector<NodeType> meta_path_;
+    float step_home_param_;  // Return hyper parameter. Default is 1.0
+    float step_away_param_;  // Inout hyper parameter. Default is 1.0
+    NodeIdType default_node_;
+
+    int32_t num_walks_;    // Number of walks per source. Default is 10
+    int32_t num_workers_;  // The number of worker threads. Default is 1
+  };
+
   // Load graph data from mindrecord file
   // @return Status - The error code return
   Status LoadNodeAndEdge();
@@ -175,6 +229,7 @@ class Graph {
   std::string dataset_file_;
   int32_t num_workers_;  // The number of worker threads
   std::mt19937 rnd_;
+  RandomWalkBase random_walk_;
 
   std::unordered_map<NodeType, std::vector<NodeIdType>> node_type_map_;
   std::unordered_map<NodeIdType, std::shared_ptr<Node>> node_id_map_;

mindspore/ccsrc/dataset/engine/gnn/local_node.cc

@@ -39,17 +39,25 @@ Status LocalNode::GetFeatures(FeatureType feature_type, std::shared_ptr<Feature>
   }
 }
 
-Status LocalNode::GetAllNeighbors(NodeType neighbor_type, std::vector<NodeIdType> *out_neighbors) {
+Status LocalNode::GetAllNeighbors(NodeType neighbor_type, std::vector<NodeIdType> *out_neighbors, bool exclude_itself) {
   std::vector<NodeIdType> neighbors;
   auto itr = neighbor_nodes_.find(neighbor_type);
   if (itr != neighbor_nodes_.end()) {
-    neighbors.resize(itr->second.size() + 1);
-    neighbors[0] = id_;
-    std::transform(itr->second.begin(), itr->second.end(), neighbors.begin() + 1,
-                   [](const std::shared_ptr<Node> node) { return node->id(); });
+    if (exclude_itself) {
+      neighbors.resize(itr->second.size());
+      std::transform(itr->second.begin(), itr->second.end(), neighbors.begin(),
+                     [](const std::shared_ptr<Node> node) { return node->id(); });
+    } else {
+      neighbors.resize(itr->second.size() + 1);
+      neighbors[0] = id_;
+      std::transform(itr->second.begin(), itr->second.end(), neighbors.begin() + 1,
+                     [](const std::shared_ptr<Node> node) { return node->id(); });
+    }
   } else {
     MS_LOG(DEBUG) << "No neighbors. node_id:" << id_ << " neighbor_type:" << neighbor_type;
-    neighbors.emplace_back(id_);
+    if (!exclude_itself) {
+      neighbors.emplace_back(id_);
+    }
   }
   *out_neighbors = std::move(neighbors);
   return Status::OK();

mindspore/ccsrc/dataset/engine/gnn/local_node.h

@@ -47,7 +47,8 @@ class LocalNode : public Node {
   // @param NodeType neighbor_type - type of neighbor
   // @param std::vector<NodeIdType> *out_neighbors - Returned neighbors id
   // @return Status - The error code return
-  Status GetAllNeighbors(NodeType neighbor_type, std::vector<NodeIdType> *out_neighbors) override;
+  Status GetAllNeighbors(NodeType neighbor_type, std::vector<NodeIdType> *out_neighbors,
+                         bool exclude_itself = false) override;
 
   // Get the sampled neighbors of a node
   // @param NodeType neighbor_type - type of neighbor

mindspore/ccsrc/dataset/engine/gnn/node.h

@@ -56,7 +56,8 @@ class Node {
   // @param NodeType neighbor_type - type of neighbor
   // @param std::vector<NodeIdType> *out_neighbors - Returned neighbors id
   // @return Status - The error code return
-  virtual Status GetAllNeighbors(NodeType neighbor_type, std::vector<NodeIdType> *out_neighbors) = 0;
+  virtual Status GetAllNeighbors(NodeType neighbor_type, std::vector<NodeIdType> *out_neighbors,
+                                 bool exclude_itself = false) = 0;
 
   // Get the sampled neighbors of a node
   // @param NodeType neighbor_type - type of neighbor

mindspore/dataset/engine/graphdata.py

@@ -22,7 +22,7 @@ from mindspore._c_dataengine import Tensor
 
 from .validators import check_gnn_graphdata, check_gnn_get_all_nodes, check_gnn_get_all_edges, \
     check_gnn_get_nodes_from_edges, check_gnn_get_all_neighbors, check_gnn_get_sampled_neighbors, \
-    check_gnn_get_neg_sampled_neighbors, check_gnn_get_node_feature
+    check_gnn_get_neg_sampled_neighbors, check_gnn_get_node_feature, check_gnn_random_walk
 
 
 class GraphData:
@@ -148,7 +148,8 @@ class GraphData:
             TypeError: If `neighbor_nums` is not list or ndarray.
             TypeError: If `neighbor_types` is not list or ndarray.
         """
-        return self._graph.get_sampled_neighbors(node_list, neighbor_nums, neighbor_types).as_array()
+        return self._graph.get_sampled_neighbors(
+            node_list, neighbor_nums, neighbor_types).as_array()
 
     @check_gnn_get_neg_sampled_neighbors
     def get_neg_sampled_neighbors(self, node_list, neg_neighbor_num, neg_neighbor_type):
@@ -174,7 +175,8 @@ class GraphData:
             TypeError: If `neg_neighbor_num` is not integer.
             TypeError: If `neg_neighbor_type` is not integer.
         """
-        return self._graph.get_neg_sampled_neighbors(node_list, neg_neighbor_num, neg_neighbor_type).as_array()
+        return self._graph.get_neg_sampled_neighbors(
+            node_list, neg_neighbor_num, neg_neighbor_type).as_array()
 
     @check_gnn_get_node_feature
     def get_node_feature(self, node_list, feature_types):
@@ -200,7 +202,10 @@ class GraphData:
         """
         if isinstance(node_list, list):
             node_list = np.array(node_list, dtype=np.int32)
-        return [t.as_array() for t in self._graph.get_node_feature(Tensor(node_list), feature_types)]
+        return [
+            t.as_array() for t in self._graph.get_node_feature(
+                Tensor(node_list),
+                feature_types)]
 
     def graph_info(self):
         """
@@ -212,3 +217,36 @@ class GraphData:
                 node_feature_type and edge_feature_type.
         """
         return self._graph.graph_info()
+
+    @check_gnn_random_walk
+    def random_walk(
+            self,
+            target_nodes,
+            meta_path,
+            step_home_param=1.0,
+            step_away_param=1.0,
+            default_node=-1):
+        """
+        Random walk in nodes.
+
+        Args:
+            target_nodes (list[int]): Start node list in random walk
+            meta_path (list[int]): node type for each walk step
+            step_home_param (float): return hyper parameter in node2vec algorithm
+            step_away_param (float): inout hyper parameter in node2vec algorithm
+            default_node (int): default node if no more neighbors found
+
+        Returns:
+            numpy.ndarray: array of nodes.
+
+        Examples:
+            >>> import mindspore.dataset as ds
+            >>> data_graph = ds.GraphData('dataset_file', 2)
+            >>> nodes = data_graph.random_walk([1,2], [1,2,1,2,1])
+
+        Raises:
+            TypeError: If `target_nodes` is not list or ndarray.
+            TypeError: If `meta_path` is not list or ndarray.
+        """
+        return self._graph.random_walk(target_nodes, meta_path, step_home_param, step_away_param,
+                                       default_node).as_array()

mindspore/dataset/engine/validators.py

@@ -1395,6 +1395,24 @@ def check_gnn_get_neg_sampled_neighbors(method):
     return new_method
 
 
+def check_gnn_random_walk(method):
+    """A wrapper that wrap a parameter checker to the GNN `random_walk` function."""
+
+    @wraps(method)
+    def new_method(*args, **kwargs):
+        param_dict = make_param_dict(method, args, kwargs)
+
+        # check node_list; required argument
+        check_gnn_list_or_ndarray(param_dict.get("target_nodes"), 'target_nodes')
+
+        # check meta_path; required argument
+        check_gnn_list_or_ndarray(param_dict.get("meta_path"), 'meta_path')
+
+        return method(*args, **kwargs)
+
+    return new_method
+
+
 def check_aligned_list(param, param_name, membor_type):
     """Check whether the structure of each member of the list is the same."""
 

tests/ut/cpp/dataset/gnn_graph_test.cc

@@ -27,6 +27,13 @@
 using namespace mindspore::dataset;
 using namespace mindspore::dataset::gnn;
 
+#define print_int_vec(_i, _str)                                           \
+  do {                                                                    \
+    std::stringstream ss;                                                 \
+    std::copy(_i.begin(), _i.end(), std::ostream_iterator<int>(ss, " ")); \
+    MS_LOG(INFO) << _str << " " << ss.str();                              \
+  } while (false)
+
 class MindDataTestGNNGraph : public UT::Common {
  protected:
   MindDataTestGNNGraph() = default;
@@ -195,3 +202,29 @@ TEST_F(MindDataTestGNNGraph, TestGetNegSampledNeighbors) {
   s = graph.GetNegSampledNeighbors(node_list, 3, 3, &neg_neighbors);
   EXPECT_TRUE(s.ToString().find("Invalid node type:3") != std::string::npos);
 }
+
+TEST_F(MindDataTestGNNGraph, TestRandomWalk) {
+  std::string path = "data/mindrecord/testGraphData/sns";
+  Graph graph(path, 1);
+  Status s = graph.Init();
+  EXPECT_TRUE(s.IsOk());
+
+  MetaInfo meta_info;
+  s = graph.GetMetaInfo(&meta_info);
+  EXPECT_TRUE(s.IsOk());
+
+  std::shared_ptr<Tensor> nodes;
+  s = graph.GetAllNodes(meta_info.node_type[0], &nodes);
+  EXPECT_TRUE(s.IsOk());
+  std::vector<NodeIdType> node_list;
+  for (auto itr = nodes->begin<NodeIdType>(); itr != nodes->end<NodeIdType>(); ++itr) {
+    node_list.push_back(*itr);
+  }
+
+  print_int_vec(node_list, "node list ");
+  std::vector<NodeType> meta_path(59, 1);
+  std::shared_ptr<Tensor> walk_path;
+  s = graph.RandomWalk(node_list, meta_path, 2.0, 0.5, -1, &walk_path);
+  EXPECT_TRUE(s.IsOk());
+  EXPECT_TRUE(walk_path->shape().ToString() == "<33,60>");
+}
\ No newline at end of file

tests/ut/python/dataset/test_graphdata.py

@@ -19,6 +19,7 @@ import mindspore.dataset as ds
 from mindspore import log as logger
 
 DATASET_FILE = "../data/mindrecord/testGraphData/testdata"
+SOCIAL_DATA_FILE = "../data/mindrecord/testGraphData/sns"
 
 
 def test_graphdata_getfullneighbor():
@@ -172,6 +173,17 @@ def test_graphdata_generatordataset():
     assert i == 40
 
 
+def test_graphdata_randomwalk():
+    g = ds.GraphData(SOCIAL_DATA_FILE, 1)
+    nodes = g.get_all_nodes(1)
+    print(len(nodes))
+    assert len(nodes) == 33
+
+    meta_path = [1 for _ in range(39)]
+    walks = g.random_walk(nodes, meta_path)
+    assert walks.shape == (33, 40)
+
+
 if __name__ == '__main__':
     test_graphdata_getfullneighbor()
     logger.info('test_graphdata_getfullneighbor Ended.\n')
@@ -185,3 +197,5 @@ if __name__ == '__main__':
     logger.info('test_graphdata_graphinfo Ended.\n')
     test_graphdata_generatordataset()
     logger.info('test_graphdata_generatordataset Ended.\n')
+    test_graphdata_randomwalk()
+    logger.info('test_graphdata_randomwalk Ended.\n')