Fix concat issue & fix schema doc

mindspore/ccsrc/minddata/dataset/engine/ir/datasetops/dataset_node.cc

@@ -233,7 +233,7 @@ std::shared_ptr<DatasetNode> DatasetNode::SetNumWorkers(int32_t num_workers) {
   return shared_from_this();
 }
 
-DatasetNode::DatasetNode() : cache_(nullptr), parent_(nullptr), children_({}) {
+DatasetNode::DatasetNode() : cache_(nullptr), parent_({}), children_({}) {
   // Fetch some default value from config manager
   std::shared_ptr<ConfigManager> cfg = GlobalContext::config_manager();
   num_workers_ = cfg->num_parallel_workers();
@@ -294,30 +294,33 @@ void DatasetNode::PrintNode(std::ostream &out, int *level) const {
 // Add a node as a child, node's parent needs to be nullptr
 // this function will allow child to be a nullptr, in which case it will simply skip
 void DatasetNode::AddChild(std::shared_ptr<DatasetNode> child) {
-  if (child != nullptr && child->parent_ == nullptr) {
+  if (child != nullptr && !child->parent_.size()) {
     children_.push_back(child);
-    child->parent_ = this;
+    child->parent_.push_back(this);
   } else if (child != nullptr) {
-    MS_LOG(WARNING) << "DatasetNode::AddChild() Fail" + child->Name() + "'s parent isn't a nullptr.";
+    MS_LOG(WARNING) << "DatasetNode::AddChild() failed: " + child->Name() + "'s parent isn't a nullptr.";
+    children_.push_back(child);
+    child->parent_.push_back(this);
   }
 }
 
 // Remove this node from its parent. Add the child of this node to its parent.
 // for now, this remove is limited to node with a single child or no child
 Status DatasetNode::Remove() {
-  CHECK_FAIL_RETURN_UNEXPECTED(parent_ != nullptr, "Cannot remove root or a node without parent.");
+  CHECK_FAIL_RETURN_UNEXPECTED(parent_.size() != 0, "Cannot remove root or a node without parent.");
   CHECK_FAIL_RETURN_UNEXPECTED(children_.size() < 2, "Cannot remove node with more than 1 child.");
   if (children_.empty()) {  // I am a leaf node, remove me from my parent's children list
-    parent_->children_.erase(std::remove(parent_->children_.begin(), parent_->children_.end(), shared_from_this()),
-                             parent_->children_.end());  // removal using "erase remove idiom"
-  } else {  // replace my position in my parent's children list with my single child
-    auto itr = std::find(parent_->children_.begin(), parent_->children_.end(), shared_from_this());
-    CHECK_FAIL_RETURN_UNEXPECTED(itr != parent_->children_.end(), "I am not in my parent's children list.");
+    parent_[0]->children_.erase(
+      std::remove(parent_[0]->children_.begin(), parent_[0]->children_.end(), shared_from_this()),
+      parent_[0]->children_.end());  // removal using "erase remove idiom"
+  } else {                           // replace my position in my parent's children list with my single child
+    auto itr = std::find(parent_[0]->children_.begin(), parent_[0]->children_.end(), shared_from_this());
+    CHECK_FAIL_RETURN_UNEXPECTED(itr != parent_[0]->children_.end(), "I am not in my parent's children list.");
     children_[0]->parent_ = parent_;  // set my single child's parent ptr to my parent
     *itr = std::move(children_[0]);   // replace me in my parent's children list with my single child
     children_.clear();                //  release my single child from my children list
   }
-  parent_ = nullptr;
+  parent_[0] = nullptr;
   return Status::OK();
 }
 

mindspore/ccsrc/minddata/dataset/engine/ir/datasetops/dataset_node.h

@@ -183,6 +183,10 @@ class DatasetNode : public std::enable_shared_from_this<DatasetNode> {
   /// \return Child nodes
   const std::vector<std::shared_ptr<DatasetNode>> Children() const { return children_; }
 
+  /// \brief Getter function for parents nodes
+  /// \return Parent nodes
+  const std::vector<DatasetNode *> Parent() const { return parent_; }
+
   /// \brief Establish the parent-child relationship between this node and its child.
   void AddChild(std::shared_ptr<DatasetNode> child);
 
@@ -233,7 +237,7 @@ class DatasetNode : public std::enable_shared_from_this<DatasetNode> {
 
  protected:
   std::vector<std::shared_ptr<DatasetNode>> children_;
-  DatasetNode *parent_;
+  std::vector<DatasetNode *> parent_;
   std::shared_ptr<DatasetCache> cache_;
   int64_t dataset_size_ = -1;
   int32_t num_workers_;

mindspore/ccsrc/minddata/dataset/engine/ir/datasetops/root_node.cc

@@ -52,7 +52,7 @@ Status RootNode::ValidateParams() {
     MS_LOG(ERROR) << err_msg;
     RETURN_STATUS_SYNTAX_ERROR(err_msg);
   }
-  if (parent_ != nullptr) {
+  if (parent_.size() != 0) {
     std::string err_msg = "Internal error: root node should not have a parent";
     MS_LOG(ERROR) << err_msg;
     RETURN_STATUS_SYNTAX_ERROR(err_msg);

mindspore/ccsrc/minddata/dataset/engine/tree_adapter.cc

@@ -96,6 +96,10 @@ Status TreeAdapter::PostPass(std::shared_ptr<DatasetNode> ir) {
 }
 
 Status TreeAdapter::BuildExecutionTree(std::shared_ptr<DatasetNode> ir, std::shared_ptr<DatasetOp> *op) {
+  // Check if pipeline is valid or not
+  CHECK_FAIL_RETURN_UNEXPECTED(ir->Parent().size() <= 1,
+                               "The data pipeline is not a tree (i.e. one node has two consumers)");
+
   // Build the DatasetOp ExecutionTree from the optimized IR tree
   std::vector<std::shared_ptr<DatasetOp>> ops = ir->Build();
   RETURN_IF_NOT_OK(ir->BuildStatus());  // remove me after changing return val of Build()

mindspore/dataset/engine/datasets.py

@@ -4511,7 +4511,7 @@ class Schema:
         Parse the columns and add it to self.
 
         Args:
-            columns (Union[dict, list[dict]]): Dataset attribute information, decoded from schema file.
+            columns (Union[dict, list[dict], tuple[dict]]): Dataset attribute information, decoded from schema file.
 
                 - list[dict], 'name' and 'type' must be in keys, 'shape' optional.
 
@@ -4519,7 +4519,6 @@ class Schema:
 
         Raises:
             RuntimeError: If failed to parse columns.
-            RuntimeError: If unknown items in columns.
             RuntimeError: If column's name field is missing.
             RuntimeError: If column's type field is missing.
 

tests/ut/cpp/dataset/c_api_dataset_ops_test.cc

@@ -415,6 +415,35 @@ TEST_F(MindDataTestPipeline, TestConcatFail4) {
   EXPECT_EQ(iter, nullptr);
 }
 
+TEST_F(MindDataTestPipeline, TestConcatFail5) {
+  MS_LOG(INFO) << "Doing MindDataTestPipeline-TestConcatFail5.";
+  // This case is expected to fail because the dataset concat itself which causes ProjectNode has two parent nodes
+
+  // Create an ImageFolder Dataset
+  std::string folder_path = datasets_root_path_ + "/testPK/data/";
+  std::shared_ptr<Dataset> ds1 = ImageFolder(folder_path, true, RandomSampler(false, 10));
+  EXPECT_NE(ds1, nullptr);
+
+  std::shared_ptr<Dataset> ds2 = ImageFolder(folder_path, true, RandomSampler(false, 10));
+  EXPECT_NE(ds2, nullptr);
+
+  // Create a Project operation on ds
+  ds1 = ds1->Project({"image"});
+  EXPECT_NE(ds1, nullptr);
+  ds2 = ds2->Project({"image"});
+  EXPECT_NE(ds2, nullptr);
+
+  // Create a Concat operation on the ds
+  // Input dataset is the dataset itself
+  ds1 = ds1 + ds1 + ds2;
+  EXPECT_NE(ds1, nullptr);
+
+  // Create an iterator over the result of the above dataset
+  std::shared_ptr<Iterator> iter = ds1->CreateIterator();
+  // Expect failure: The data pipeline is not a tree
+  EXPECT_EQ(iter, nullptr);
+}
+
 TEST_F(MindDataTestPipeline, TestConcatSuccess) {
   MS_LOG(INFO) << "Doing MindDataTestPipeline-TestConcatSuccess.";