mindrecord support read file list

mindspore/ccsrc/dataset/api/de_pipeline.cc

@@ -408,8 +408,13 @@ Status DEPipeline::ParseMindRecordOp(const py::dict &args, std::shared_ptr<Datas
   }
 
   std::shared_ptr<MindRecordOp::Builder> builder = std::make_shared<MindRecordOp::Builder>();
-  (void)builder->SetDatasetFile(ToString(args["dataset_file"]));
-
+  bool load_dataset = ToBool(args["load_dataset"]);
+  if (load_dataset == true) {
+    (void)builder->SetDatasetFile({ToString(args["dataset_file"])});
+  } else {
+    (void)builder->SetDatasetFile(ToStringVector(args["dataset_file"]));
+  }
+  (void)builder->SetLoadDataset(load_dataset);
   std::vector<std::string> in_col_names;
   if (!args["columns_list"].is_none()) {
     in_col_names = ToStringVector(args["columns_list"]);

mindspore/ccsrc/dataset/api/python_bindings.cc

@@ -151,16 +151,17 @@ void bindDatasetOps(py::module *m) {
     });
 
   (void)py::class_<MindRecordOp, DatasetOp, std::shared_ptr<MindRecordOp>>(*m, "MindRecordOp")
-    .def_static("get_num_rows", [](const std::string &path, const py::object &sampler) {
-      int64_t count = 0;
-      std::shared_ptr<mindrecord::ShardOperator> op;
-      if (py::hasattr(sampler, "_create_for_minddataset")) {
-        auto create = sampler.attr("_create_for_minddataset");
-        op = create().cast<std::shared_ptr<mindrecord::ShardOperator>>();
-      }
-      THROW_IF_ERROR(MindRecordOp::CountTotalRows(path, op, &count));
-      return count;
-    });
+    .def_static("get_num_rows",
+                [](const std::vector<std::string> &paths, bool load_dataset, const py::object &sampler) {
+                  int64_t count = 0;
+                  std::shared_ptr<mindrecord::ShardOperator> op;
+                  if (py::hasattr(sampler, "_create_for_minddataset")) {
+                    auto create = sampler.attr("_create_for_minddataset");
+                    op = create().cast<std::shared_ptr<mindrecord::ShardOperator>>();
+                  }
+                  THROW_IF_ERROR(MindRecordOp::CountTotalRows(paths, load_dataset, op, &count));
+                  return count;
+                });
 
   (void)py::class_<ManifestOp, DatasetOp, std::shared_ptr<ManifestOp>>(*m, "ManifestOp")
     .def_static("get_num_rows_and_classes",

mindspore/ccsrc/dataset/engine/datasetops/source/mindrecord_op.cc

@@ -40,7 +40,7 @@ using mindrecord::ShardOperator;
 using mindrecord::ShardReader;
 
 // Builder constructor.  Creates the builder object.
-MindRecordOp::Builder::Builder() : build_dataset_file_("") {
+MindRecordOp::Builder::Builder() : build_dataset_file_({}) {
   // Some arguments to the MindRecordOp constructor have a default argument that is taken
   // from the client config.
   // The user may choose to change these values for the construction of the StorageOp by
@@ -63,9 +63,9 @@ Status MindRecordOp::Builder::Build(std::shared_ptr<MindRecordOp> *ptr) {
                   "Building a MindRecordOp that has not provided a file.");
   }
 
-  new_mind_record_op = std::make_shared<MindRecordOp>(build_num_mind_record_workers_, build_rows_per_buffer_,
-                                                      build_dataset_file_, build_op_connector_queue_size_,
-                                                      build_columns_to_load_, build_operators_, build_block_reader_);
+  new_mind_record_op = std::make_shared<MindRecordOp>(
+    build_num_mind_record_workers_, build_rows_per_buffer_, build_dataset_file_, build_load_dataset_,
+    build_op_connector_queue_size_, build_columns_to_load_, build_operators_, build_block_reader_);
 
   RETURN_IF_NOT_OK(new_mind_record_op->Init());
 
@@ -76,12 +76,14 @@ Status MindRecordOp::Builder::Build(std::shared_ptr<MindRecordOp> *ptr) {
 Status MindRecordOp::Builder::SanityCheck() const { return Status::OK(); }
 
 // Constructor of the MindRecordOp.
-MindRecordOp::MindRecordOp(int32_t num_mind_record_workers, int32_t rows_per_buffer, std::string dataset_file,
-                           int32_t op_connector_queue_size, const std::vector<std::string> &columns_to_load,
+MindRecordOp::MindRecordOp(int32_t num_mind_record_workers, int32_t rows_per_buffer,
+                           std::vector<std::string> dataset_file, bool load_dataset, int32_t op_connector_queue_size,
+                           const std::vector<std::string> &columns_to_load,
                            const std::vector<std::shared_ptr<ShardOperator>> &operators, const bool &block_reader)
     : ParallelOp(num_mind_record_workers, op_connector_queue_size),
       rows_per_buffer_(rows_per_buffer),
       dataset_file_(dataset_file),
+      load_dataset_(load_dataset),
       columns_to_load_(columns_to_load),
       operators_(operators),
       num_mind_record_workers_(num_mind_record_workers),
@@ -101,9 +103,10 @@ MindRecordOp::MindRecordOp(int32_t num_mind_record_workers, int32_t rows_per_buf
 // Private helper method to encapsulate some common construction/reset tasks
 Status MindRecordOp::Init() {
   shard_reader_ = std::make_unique<ShardReader>();
-  auto rc = shard_reader_->Open(dataset_file_, num_mind_record_workers_, columns_to_load_, operators_, block_reader_);
+  auto rc = shard_reader_->Open(dataset_file_, load_dataset_, num_mind_record_workers_, columns_to_load_, operators_,
+                                block_reader_);
 
-  CHECK_FAIL_RETURN_UNEXPECTED(rc != MSRStatus::FAILED,
+  CHECK_FAIL_RETURN_UNEXPECTED(rc == MSRStatus::SUCCESS,
                                "MindRecordOp init failed. Error message: " + ErrnoToMessage(rc));
 
   data_schema_ = std::make_unique<DataSchema>();
@@ -201,8 +204,12 @@ void MindRecordOp::Print(std::ostream &out, bool show_all) const {
     // Call the super class for displaying any common detailed info
     ParallelOp::Print(out, show_all);
     // Then show any custom derived-internal stuff
-    out << "\n1 Dataset file : " << dataset_file_ << "\nNumber of rows : " << num_rows_
-        << "\nRows per buffer : " << rows_per_buffer_ << "\nNumber of buffers : " << buffers_needed_
+    out << "\n Dataset file : ";
+    for (auto &file : dataset_file_) {
+      out << file << " ";
+    }
+    out << "\nNumber of rows : " << num_rows_ << "\nRows per buffer : " << rows_per_buffer_
+        << "\nNumber of buffers : " << buffers_needed_
         << "\nNumber of ShardReader workers : " << num_mind_record_workers_ << "\n\n";
   }
 }
@@ -668,10 +675,10 @@ Status MindRecordOp::LaunchThreadAndInitOp() {
   return Status::OK();
 }
 
-Status MindRecordOp::CountTotalRows(const std::string dataset_path, const std::shared_ptr<ShardOperator> &op,
-                                    int64_t *count) {
+Status MindRecordOp::CountTotalRows(const std::vector<std::string> dataset_path, bool load_dataset,
+                                    const std::shared_ptr<ShardOperator> &op, int64_t *count) {
   std::unique_ptr<ShardReader> shard_reader = std::make_unique<ShardReader>();
-  MSRStatus rc = shard_reader->CountTotalRows(dataset_path, op, count);
+  MSRStatus rc = shard_reader->CountTotalRows(dataset_path, load_dataset, op, count);
   if (rc == MSRStatus::FAILED) {
     RETURN_STATUS_UNEXPECTED("MindRecordOp count total rows failed.");
   }

mindspore/ccsrc/dataset/engine/datasetops/source/mindrecord_op.h

@@ -77,8 +77,8 @@ class MindRecordOp : public ParallelOp {
       return *this;
     }
 
-    Builder &SetDatasetFile(const std::string &file) {
-      build_dataset_file_ = file;
+    Builder &SetDatasetFile(const std::vector<std::string> &files) {
+      build_dataset_file_ = files;
       return *this;
     }
 
@@ -97,6 +97,11 @@ class MindRecordOp : public ParallelOp {
       return *this;
     }
 
+    Builder &SetLoadDataset(bool load_dataset) {
+      build_load_dataset_ = load_dataset;
+      return *this;
+    }
+
     Status SanityCheck() const;
 
     static int32_t num_mind_record_workers() { return kDefaultMindRecordWorkers; }
@@ -109,7 +114,8 @@ class MindRecordOp : public ParallelOp {
     int32_t builder_num_workers_;
     int32_t build_rows_per_buffer_;
     int32_t build_op_connector_queue_size_;
-    std::string build_dataset_file_;
+    std::vector<std::string> build_dataset_file_;
+    bool build_load_dataset_;
     std::vector<std::string> build_columns_to_load_;
     std::vector<std::shared_ptr<ShardOperator>> build_operators_;
     bool build_block_reader_;
@@ -119,12 +125,12 @@ class MindRecordOp : public ParallelOp {
   // @note The builder class should be used to call it
   // @param num_mind_record_workers - The number of workers for the op (run by ShardReader)
   // @param rows_per_buffer - The requested number of rows per buffer
-  // @param dataset_file - A shard file
+  // @param dataset_file - dataset files
   // @param op_connector_queue_size - The output connector queue size
   // @param columns_to_load - The list of columns to use (column name)
   // @param operators - ShardOperators for Shuffle, Category, Sample
-  MindRecordOp(int32_t num_mind_record_workers, int32_t rows_per_buffer, std::string dataset_file,
-               int32_t op_connector_queue_size, const std::vector<std::string> &columns_to_load,
+  MindRecordOp(int32_t num_mind_record_workers, int32_t rows_per_buffer, std::vector<std::string> dataset_file,
+               bool load_dataset, int32_t op_connector_queue_size, const std::vector<std::string> &columns_to_load,
                const std::vector<std::shared_ptr<ShardOperator>> &operators, const bool &block_reader);
 
   // Destructor
@@ -169,21 +175,22 @@ class MindRecordOp : public ParallelOp {
   // Getter method
   int32_t num_rows() const { return num_rows_; }
 
-  // Getter method
-  static Status CountTotalRows(const std::string dataset_path, const std::shared_ptr<ShardOperator> &op,
-                               int64_t *count);
+  static Status CountTotalRows(const std::vector<std::string> dataset_path, bool load_dataset,
+                               const std::shared_ptr<ShardOperator> &op, int64_t *count);
 
   // Getter method
   int32_t rows_per_buffer() const { return rows_per_buffer_; }
 
   // Getter method
-  std::string dataset_file() const { return dataset_file_; }
+  std::vector<std::string> dataset_file() const { return dataset_file_; }
 
   // Getter method
   std::vector<std::string> columns_to_load() const { return columns_to_load_; }
 
   bool block_reader() const { return block_reader_; }
 
+  bool load_dataset() const { return load_dataset_; }
+
   Status Init();
 
   Status SetColumnsBlob();
@@ -246,7 +253,8 @@ class MindRecordOp : public ParallelOp {
   Status FetchBlockBuffer(const int32_t &buffer_id);
 
   int32_t rows_per_buffer_;                                // The number of requested rows per buffer.
-  std::string dataset_file_;                               // A dataset file
+  std::vector<std::string> dataset_file_;                  // dataset files
+  bool load_dataset_;                                      // load dataset from single file or not
   std::vector<std::string> columns_to_load_;               // Columns to load from dataset
   std::vector<std::shared_ptr<ShardOperator>> operators_;  // ShardOperators to use
   int32_t num_mind_record_workers_;                        // number of workers to be spawned by ShardReader

mindspore/ccsrc/mindrecord/common/shard_error.cc

@@ -170,6 +170,9 @@ std::string ErrnoToMessage(MSRStatus status) {
     case IO_FAILED:
       return "io operate failed";
       break;
+    case MATCH_HEADER_FAILED:
+      return "match header failed";
+      break;
     default:
       return "invalid error no";
   }

mindspore/ccsrc/mindrecord/common/shard_pybind.cc

@@ -84,7 +84,8 @@ void BindShardWriter(py::module *m) {
 void BindShardReader(const py::module *m) {
   (void)py::class_<ShardReader, std::shared_ptr<ShardReader>>(*m, "ShardReader", py::module_local())
     .def(py::init<>())
-    .def("open", (MSRStatus(ShardReader::*)(const std::string &, const int &, const std::vector<std::string> &,
+    .def("open", (MSRStatus(ShardReader::*)(const std::vector<std::string> &, bool, const int &,
+                                            const std::vector<std::string> &,
                                             const std::vector<std::shared_ptr<ShardOperator>> &)) &
                    ShardReader::OpenPy)
     .def("launch", &ShardReader::Launch)
@@ -106,7 +107,8 @@ void BindShardIndexGenerator(const py::module *m) {
 void BindShardSegment(py::module *m) {
   (void)py::class_<ShardSegment>(*m, "ShardSegment", py::module_local())
     .def(py::init<>())
-    .def("open", (MSRStatus(ShardSegment::*)(const std::string &, const int &, const std::vector<std::string> &,
+    .def("open", (MSRStatus(ShardSegment::*)(const std::vector<std::string> &, bool, const int &,
+                                             const std::vector<std::string> &,
                                              const std::vector<std::shared_ptr<ShardOperator>> &)) &
                    ShardSegment::OpenPy)
     .def("get_category_fields",

mindspore/ccsrc/mindrecord/include/shard_error.h

@@ -72,7 +72,8 @@ enum MSRStatus {
   ILLEGAL_PARAMETERS,
   GET_PAGE_BY_GROUP_ID_FAILED,
   GET_SYSTEM_STATE_FAILED,
-  IO_FAILED
+  IO_FAILED,
+  MATCH_HEADER_FAILED
 };
 
 // convert error no to string message

mindspore/ccsrc/mindrecord/include/shard_header.h

@@ -35,10 +35,11 @@ class ShardHeader {
  public:
   ShardHeader();
 
-  MSRStatus Build(const std::string &file_path);
-
   ~ShardHeader() = default;
 
+  MSRStatus BuildDataset(const std::vector<std::string> &file_paths, bool load_dataset = true);
+
+  static std::pair<MSRStatus, json> BuildSingleHeader(const std::string &file_path);
   /// \brief add the schema and save it
   /// \param[in] schema the schema needs to be added
   /// \return the last schema's id
@@ -126,7 +127,7 @@ class ShardHeader {
   MSRStatus FileToPages(const std::string dump_file_name);
 
  private:
-  MSRStatus InitializeHeader(const std::vector<json> &headers);
+  MSRStatus InitializeHeader(const std::vector<json> &headers, bool load_dataset);
 
   /// \brief get the headers from all the shard data
   /// \param[in] the shard data real path
@@ -137,9 +138,9 @@ class ShardHeader {
   MSRStatus ValidateField(const std::vector<std::string> &field_name, json schema, const uint64_t &schema_id);
 
   /// \brief check the binary file status
-  MSRStatus CheckFileStatus(const std::string &path);
+  static MSRStatus CheckFileStatus(const std::string &path);
 
-  std::pair<MSRStatus, json> ValidateHeader(const std::string &path);
+  static std::pair<MSRStatus, json> ValidateHeader(const std::string &path);
 
   void ParseHeader(const json &header);
 
@@ -149,7 +150,7 @@ class ShardHeader {
 
   MSRStatus CheckIndexField(const std::string &field, const json &schema);
 
-  void ParsePage(const json &page);
+  void ParsePage(const json &page, int shard_index, bool load_dataset);
 
   MSRStatus ParseStatistics(const json &statistics);
 

mindspore/ccsrc/mindrecord/include/shard_reader.h

@@ -68,23 +68,25 @@ class ShardReader {
   virtual ~ShardReader();
 
   /// \brief open files and initialize reader, c++ API
-  /// \param[in] file_path the path of ONE file, any file in dataset is fine
+  /// \param[in] file_paths the path of ONE file, any file in dataset is fine or file list
+  /// \param[in] load_dataset load dataset from single file or not
   /// \param[in] n_consumer number of threads when reading
   /// \param[in] selected_columns column list to be populated
   /// \param[in] operators operators applied to data, operator type is shuffle, sample or category
   /// \param[in] block_reader block-reader mode if true, otherwise row-reader mode
   /// \return MSRStatus the status of MSRStatus
-  MSRStatus Open(const std::string &file_path, int n_consumer = 4,
+  MSRStatus Open(const std::vector<std::string> &file_paths, bool load_dataset, int n_consumer = 4,
                  const std::vector<std::string> &selected_columns = {},
                  const std::vector<std::shared_ptr<ShardOperator>> &operators = {}, const bool &block_reader = false);
 
   /// \brief open files and initialize reader, python API
-  /// \param[in] file_path the path of ONE file, any file in dataset is fine
+  /// \param[in] file_paths the path of ONE file, any file in dataset is fine or file list
+  /// \param[in] load_dataset load dataset from single file or not
   /// \param[in] n_consumer number of threads when reading
   /// \param[in] selected_columns column list to be populated
   /// \param[in] operators operators applied to data, operator type is shuffle, sample or category
   /// \return MSRStatus the status of MSRStatus
-  MSRStatus OpenPy(const std::string &file_path, const int &n_consumer = 4,
+  MSRStatus OpenPy(const std::vector<std::string> &file_paths, bool load_dataset, const int &n_consumer = 4,
                    const std::vector<std::string> &selected_columns = {},
                    const std::vector<std::shared_ptr<ShardOperator>> &operators = {});
 
@@ -114,11 +116,13 @@ class ShardReader {
   int GetShardCount() const;
 
   /// \brief get the number of rows in database
-  /// \param[in] file_path the path of ONE file, any file in dataset is fine
+  /// \param[in] file_paths the path of ONE file, any file in dataset is fine or file list
+  /// \param[in] load_dataset load dataset from single file or not
   /// \param[in] op smart pointer refer to ShardCategory or ShardSample object
   /// \param[out] count # of rows
   /// \return MSRStatus the status of MSRStatus
-  MSRStatus CountTotalRows(const std::string &file_path, const std::shared_ptr<ShardOperator> &op, int64_t *count);
+  MSRStatus CountTotalRows(const std::vector<std::string> &file_paths, bool load_dataset,
+                           const std::shared_ptr<ShardOperator> &op, int64_t *count);
 
   /// \brief shuffle task with incremental seed
   /// \return void
@@ -220,7 +224,7 @@ class ShardReader {
                                std::vector<std::vector<json>> &column_values);
 
   /// \brief initialize reader
-  MSRStatus Init(const std::string &file_path);
+  MSRStatus Init(const std::vector<std::string> &file_paths, bool load_dataset);
 
   /// \brief validate column list
   MSRStatus CheckColumnList(const std::vector<std::string> &selected_columns);
@@ -292,8 +296,9 @@ class ShardReader {
   void GetClassesInShard(sqlite3 *db, int shard_id, const std::string sql, std::set<std::string> &categories);
 
   /// \brief get number of classes
-  int64_t GetNumClasses(const std::string &file_path, const std::string &category_field);
+  int64_t GetNumClasses(const std::string &category_field);
 
+  std::pair<MSRStatus, std::vector<std::string>> GetMeta(const std::string &file_path, json &meta_data);
   /// \brief get exactly blob fields data by indices
   std::vector<uint8_t> ExtractBlobFieldBySelectColumns(std::vector<uint8_t> &blob_fields_bytes,
                                                        std::vector<uint32_t> &ordered_selected_columns_index);

mindspore/ccsrc/mindrecord/io/shard_index_generator.cc

@@ -36,9 +36,23 @@ ShardIndexGenerator::ShardIndexGenerator(const std::string &file_path, bool appe
       write_success_(true) {}
 
 MSRStatus ShardIndexGenerator::Build() {
+  auto ret = ShardHeader::BuildSingleHeader(file_path_);
+  if (ret.first != SUCCESS) {
+    return FAILED;
+  }
+  auto json_header = ret.second;
+
+  auto ret2 = GetParentDir(file_path_);
+  if (SUCCESS != ret2.first) {
+    return FAILED;
+  }
+  std::vector<std::string> real_addresses;
+  for (const auto &path : json_header["shard_addresses"]) {
+    std::string abs_path = ret2.second + string(path);
+    real_addresses.emplace_back(abs_path);
+  }
   ShardHeader header = ShardHeader();
-  if (header.Build(file_path_) != SUCCESS) {
-    MS_LOG(ERROR) << "Build shard schema failed.";
+  if (header.BuildDataset(real_addresses) == FAILED) {
     return FAILED;
   }
   shard_header_ = header;

mindspore/ccsrc/mindrecord/io/shard_reader.cc

@@ -47,20 +47,55 @@ ShardReader::ShardReader() {
   block_reader_ = false;
 }
 
-MSRStatus ShardReader::Init(const std::string &file_path) {
+std::pair<MSRStatus, std::vector<std::string>> ShardReader::GetMeta(const std::string &file_path, json &meta_data) {
   if (!IsLegalFile(file_path)) {
+    return {FAILED, {}};
+  }
+  auto ret = ShardHeader::BuildSingleHeader(file_path);
+  if (ret.first != SUCCESS) {
+    return {FAILED, {}};
+  }
+  auto header = ret.second;
+  meta_data = {{"header_size", header["header_size"]}, {"page_size", header["page_size"]},
+               {"version", header["version"]},         {"index_fields", header["index_fields"]},
+               {"schema", header["schema"]},           {"blob_fields", header["blob_fields"]}};
+  return {SUCCESS, header["shard_addresses"]};
+}
+
+MSRStatus ShardReader::Init(const std::vector<std::string> &file_paths, bool load_dataset) {
+  std::string file_path = file_paths[0];
+  json first_meta_data = json();
+  auto ret = GetMeta(file_path, first_meta_data);
+  if (ret.first != SUCCESS) {
     return FAILED;
   }
-  ShardHeader sh = ShardHeader();
-  if (sh.Build(file_path) == FAILED) {
+  if (file_paths.size() == 1 && load_dataset == true) {
+    auto ret2 = GetParentDir(file_path);
+    if (SUCCESS != ret2.first) {
+      return FAILED;
+    }
+    std::vector<std::string> real_addresses;
+    for (const auto &path : ret.second) {
+      std::string abs_path = ret2.second + string(path);
+      real_addresses.emplace_back(abs_path);
+    }
+    file_paths_ = real_addresses;
+  } else if (file_paths.size() >= 1 && load_dataset == false) {
+    file_paths_ = file_paths;
+  } else {
+    MS_LOG(ERROR) << "Error in parameter file_path or load_dataset.";
     return FAILED;
   }
-  shard_header_ = std::make_shared<ShardHeader>(sh);
-  header_size_ = shard_header_->GetHeaderSize();
-  page_size_ = shard_header_->GetPageSize();
-  file_paths_ = shard_header_->GetShardAddresses();
-
   for (const auto &file : file_paths_) {
+    json meta_data = json();
+    auto ret1 = GetMeta(file, meta_data);
+    if (ret1.first != SUCCESS) {
+      return FAILED;
+    }
+    if (meta_data != first_meta_data) {
+      MS_LOG(ERROR) << "Mindrecord files meta information is different.";
+      return FAILED;
+    }
     sqlite3 *db = nullptr;
     // sqlite3_open create a database if not found, use sqlite3_open_v2 instead of it
     int rc = sqlite3_open_v2(common::SafeCStr(file + ".db"), &db, SQLITE_OPEN_READONLY, nullptr);
@@ -91,7 +126,13 @@ MSRStatus ShardReader::Init(const std::string &file_path) {
     }
     database_paths_.push_back(db);
   }
-
+  ShardHeader sh = ShardHeader();
+  if (sh.BuildDataset(file_paths_, load_dataset) == FAILED) {
+    return FAILED;
+  }
+  shard_header_ = std::make_shared<ShardHeader>(sh);
+  header_size_ = shard_header_->GetHeaderSize();
+  page_size_ = shard_header_->GetPageSize();
   num_rows_ = 0;
   auto row_group_summary = ReadRowGroupSummary();
   for (const auto &rg : row_group_summary) {
@@ -248,7 +289,6 @@ MSRStatus ShardReader::ConvertLabelToJson(const std::vector<std::vector<std::str
         fs->close();
         return FAILED;
       }
-
       json label_json = json::from_msgpack(label_raw);
       json tmp;
       if (!columns.empty()) {
@@ -713,15 +753,9 @@ MSRStatus ShardReader::Finish() {
   return SUCCESS;
 }
 
-int64_t ShardReader::GetNumClasses(const std::string &file_path, const std::string &category_field) {
-  ShardHeader sh = ShardHeader();
-  if (sh.Build(file_path) == FAILED) {
-    return -1;
-  }
-  auto header = std::make_shared<ShardHeader>(sh);
-  auto file_paths = header->GetShardAddresses();
-  auto shard_count = file_paths.size();
-  auto index_fields = header->GetFields();
+int64_t ShardReader::GetNumClasses(const std::string &category_field) {
+  auto shard_count = file_paths_.size();
+  auto index_fields = shard_header_->GetFields();
 
   std::map<std::string, int64_t> map_schema_id_fields;
   for (auto &field : index_fields) {
@@ -742,7 +776,7 @@ int64_t ShardReader::GetNumClasses(const std::string &file_path, const std::stri
   std::set<std::string> categories;
   for (int x = 0; x < shard_count; x++) {
     sqlite3 *db = nullptr;
-    int rc = sqlite3_open_v2(common::SafeCStr(file_paths[x] + ".db"), &db, SQLITE_OPEN_READONLY, nullptr);
+    int rc = sqlite3_open_v2(common::SafeCStr(file_paths_[x] + ".db"), &db, SQLITE_OPEN_READONLY, nullptr);
     if (SQLITE_OK != rc) {
       MS_LOG(ERROR) << "Can't open database, error: " << sqlite3_errmsg(db);
       return -1;
@@ -756,16 +790,16 @@ int64_t ShardReader::GetNumClasses(const std::string &file_path, const std::stri
   return categories.size();
 }
 
-MSRStatus ShardReader::CountTotalRows(const std::string &file_path, const std::shared_ptr<ShardOperator> &op,
-                                      int64_t *count) {
-  if (Init(file_path) == FAILED) {
+MSRStatus ShardReader::CountTotalRows(const std::vector<std::string> &file_paths, bool load_dataset,
+                                      const std::shared_ptr<ShardOperator> &op, int64_t *count) {
+  if (SUCCESS != Init(file_paths, load_dataset)) {
     return FAILED;
   }
   int64_t num_samples = num_rows_;
   if (std::dynamic_pointer_cast<ShardCategory>(op)) {
     auto category_op = std::dynamic_pointer_cast<ShardCategory>(op);
     std::string category_field = category_op->GetCategoryField();
-    auto num_classes = GetNumClasses(file_path, category_field);
+    auto num_classes = GetNumClasses(category_field);
     num_samples = category_op->GetNumSamples(num_rows_, num_classes);
   } else if (std::dynamic_pointer_cast<ShardSample>(op)) {
     num_samples = op->GetNumSamples(num_rows_, 0);
@@ -779,12 +813,13 @@ MSRStatus ShardReader::CountTotalRows(const std::string &file_path, const std::s
   return SUCCESS;
 }
 
-MSRStatus ShardReader::Open(const std::string &file_path, int n_consumer,
+MSRStatus ShardReader::Open(const std::vector<std::string> &file_paths, bool load_dataset, int n_consumer,
                             const std::vector<std::string> &selected_columns,
                             const std::vector<std::shared_ptr<ShardOperator>> &operators, const bool &block_reader) {
   // Open file and set header by ShardReader
-  if (Init(file_path) == FAILED) {
-    return FAILED;
+  auto ret = Init(file_paths, load_dataset);
+  if (SUCCESS != ret) {
+    return ret;
   }
   auto thread_limit = GetMaxThreadNum();
   if (n_consumer > thread_limit) {
@@ -837,11 +872,11 @@ MSRStatus ShardReader::Open(const std::string &file_path, int n_consumer,
   return SUCCESS;
 }
 
-MSRStatus ShardReader::OpenPy(const std::string &file_path, const int &n_consumer,
+MSRStatus ShardReader::OpenPy(const std::vector<std::string> &file_paths, bool load_dataset, const int &n_consumer,
                               const std::vector<std::string> &selected_columns,
                               const std::vector<std::shared_ptr<ShardOperator>> &operators) {
   // Open file and set header by ShardReader
-  if (Init(file_path) == FAILED) {
+  if (SUCCESS != Init(file_paths, load_dataset)) {
     return FAILED;
   }
   // should remove blob field from selected_columns when call from python

mindspore/ccsrc/mindrecord/io/shard_writer.cc

@@ -174,12 +174,25 @@ MSRStatus ShardWriter::OpenForAppend(const std::string &path) {
   if (!IsLegalFile(path)) {
     return FAILED;
   }
-  ShardHeader sh = ShardHeader();
-  if (sh.Build(path) == FAILED) {
+  auto ret1 = ShardHeader::BuildSingleHeader(path);
+  if (ret1.first != SUCCESS) {
     return FAILED;
   }
-  shard_header_ = std::make_shared<ShardHeader>(sh);
-  auto paths = shard_header_->GetShardAddresses();
+  auto json_header = ret1.second;
+  auto ret2 = GetParentDir(path);
+  if (SUCCESS != ret2.first) {
+    return FAILED;
+  }
+  std::vector<std::string> real_addresses;
+  for (const auto &path : json_header["shard_addresses"]) {
+    std::string abs_path = ret2.second + string(path);
+    real_addresses.emplace_back(abs_path);
+  }
+  ShardHeader header = ShardHeader();
+  if (header.BuildDataset(real_addresses) == FAILED) {
+    return FAILED;
+  }
+  shard_header_ = std::make_shared<ShardHeader>(header);
   MSRStatus ret = SetHeaderSize(shard_header_->GetHeaderSize());
   if (ret == FAILED) {
     return FAILED;
@@ -188,7 +201,7 @@ MSRStatus ShardWriter::OpenForAppend(const std::string &path) {
   if (ret == FAILED) {
     return FAILED;
   }
-  ret = Open(paths, true);
+  ret = Open(json_header["shard_addresses"], true);
   if (ret == FAILED) {
     MS_LOG(ERROR) << "Open file failed";
     return FAILED;

mindspore/ccsrc/mindrecord/meta/shard_header.cc

@@ -35,8 +35,9 @@ namespace mindrecord {
 std::atomic<bool> thread_status(false);
 ShardHeader::ShardHeader() : shard_count_(0), header_size_(0), page_size_(0) { index_ = std::make_shared<Index>(); }
 
-MSRStatus ShardHeader::InitializeHeader(const std::vector<json> &headers) {
+MSRStatus ShardHeader::InitializeHeader(const std::vector<json> &headers, bool load_dataset) {
   shard_count_ = headers.size();
+  int shard_index = 0;
   bool first = true;
   for (const auto &header : headers) {
     if (first) {
@@ -54,7 +55,8 @@ MSRStatus ShardHeader::InitializeHeader(const std::vector<json> &headers) {
       header_size_ = header["header_size"].get<uint64_t>();
       page_size_ = header["page_size"].get<uint64_t>();
     }
-    ParsePage(header["page"]);
+    ParsePage(header["page"], shard_index, load_dataset);
+    shard_index++;
   }
   return SUCCESS;
 }
@@ -136,40 +138,39 @@ std::pair<MSRStatus, json> ShardHeader::ValidateHeader(const std::string &path)
   return {SUCCESS, json_header};
 }
 
-MSRStatus ShardHeader::Build(const std::string &file_path) {
+std::pair<MSRStatus, json> ShardHeader::BuildSingleHeader(const std::string &file_path) {
   auto ret = ValidateHeader(file_path);
   if (SUCCESS != ret.first) {
-    return FAILED;
-  }
-  json main_header = ret.second;
-  json addresses = main_header["shard_addresses"];
-  vector<string> real_addresses;
-  auto ret1 = GetParentDir(file_path);
-  if (SUCCESS != ret1.first) {
-    return FAILED;
+    return {FAILED, json()};
   }
-  std::string parent_dir = ret1.second;
+  json raw_header = ret.second;
+  json header = {{"shard_addresses", raw_header["shard_addresses"]},
+                 {"header_size", raw_header["header_size"]},
+                 {"page_size", raw_header["page_size"]},
+                 {"index_fields", raw_header["index_fields"]},
+                 {"blob_fields", raw_header["schema"][0]["blob_fields"]},
+                 {"schema", raw_header["schema"][0]["schema"]},
+                 {"version", raw_header["version"]}};
+  return {SUCCESS, header};
+}
 
-  for (const auto &addr : addresses) {
-    std::string absolute_path = parent_dir + string(addr);
-    real_addresses.emplace_back(absolute_path);
-  }
+MSRStatus ShardHeader::BuildDataset(const std::vector<std::string> &file_paths, bool load_dataset) {
   uint32_t thread_num = std::thread::hardware_concurrency();
   if (thread_num == 0) thread_num = kThreadNumber;
   uint32_t work_thread_num = 0;
-  uint32_t addr_count = real_addresses.size();
-  int group_num = ceil(addr_count * 1.0 / thread_num);
+  uint32_t shard_count = file_paths.size();
+  int group_num = ceil(shard_count * 1.0 / thread_num);
   std::vector<std::thread> thread_set(thread_num);
-  std::vector<json> headers(addr_count);
+  std::vector<json> headers(shard_count);
   for (uint32_t x = 0; x < thread_num; ++x) {
     int start_num = x * group_num;
-    int end_num = ((x + 1) * group_num > addr_count) ? addr_count : (x + 1) * group_num;
+    int end_num = ((x + 1) * group_num > shard_count) ? shard_count : (x + 1) * group_num;
     if (start_num >= end_num) {
       continue;
     }
 
     thread_set[x] =
-      std::thread(&ShardHeader::GetHeadersOneTask, this, start_num, end_num, std::ref(headers), real_addresses);
+      std::thread(&ShardHeader::GetHeadersOneTask, this, start_num, end_num, std::ref(headers), file_paths);
     work_thread_num++;
   }
 
@@ -180,7 +181,7 @@ MSRStatus ShardHeader::Build(const std::string &file_path) {
     thread_status = false;
     return FAILED;
   }
-  if (SUCCESS != InitializeHeader(headers)) {
+  if (SUCCESS != InitializeHeader(headers, load_dataset)) {
     return FAILED;
   }
   return SUCCESS;
@@ -247,7 +248,8 @@ MSRStatus ShardHeader::ParseIndexFields(const json &index_fields) {
   return SUCCESS;
 }
 
-void ShardHeader::ParsePage(const json &pages) {
+void ShardHeader::ParsePage(const json &pages, int shard_index, bool load_dataset) {
+  // set shard_index when load_dataset is false
   if (pages_.empty() && shard_count_ <= kMaxShardCount) {
     pages_.resize(shard_count_);
   }
@@ -267,7 +269,11 @@ void ShardHeader::ParsePage(const json &pages) {
 
     std::shared_ptr<Page> parsed_page = std::make_shared<Page>(page_id, shard_id, page_type, page_type_id, start_row_id,
                                                                end_row_id, row_group_ids, page_size);
-    pages_[shard_id].push_back(std::move(parsed_page));
+    if (load_dataset == true) {
+      pages_[shard_id].push_back(std::move(parsed_page));
+    } else {
+      pages_[shard_index].push_back(std::move(parsed_page));
+    }
   }
 }
 
@@ -709,7 +715,7 @@ MSRStatus ShardHeader::FileToPages(const std::string dump_file_name) {
 
   std::string line;
   while (std::getline(page_in_handle, line)) {
-    ParsePage(json::parse(line));
+    ParsePage(json::parse(line), -1, true);
   }
 
   page_in_handle.close();

mindspore/dataset/engine/datasets.py

@@ -2189,7 +2189,7 @@ class MindDataset(SourceDataset):
     A source dataset that reads from shard files and database.
 
     Args:
-        dataset_file (str): one of file names in dataset.
+        dataset_file (str, list[str]): One of file names or file list in dataset.
         columns_list (list[str], optional): List of columns to be read (default=None).
         num_parallel_workers (int, optional): The number of readers (default=None).
         shuffle (bool, optional): Whether or not to perform shuffle on the dataset
@@ -2214,6 +2214,10 @@ class MindDataset(SourceDataset):
                  shuffle=None, num_shards=None, shard_id=None,
                  block_reader=False, sampler=None):
         super().__init__(num_parallel_workers)
+        if isinstance(dataset_file, list):
+            self.load_dataset = False
+        else:
+            self.load_dataset = True
         self.dataset_file = dataset_file
         self.columns_list = columns_list
         self.global_shuffle = shuffle
@@ -2256,6 +2260,7 @@ class MindDataset(SourceDataset):
     def get_args(self):
         args = super().get_args()
         args["dataset_file"] = self.dataset_file
+        args["load_dataset"] = self.load_dataset
         args["columns_list"] = self.columns_list
         args["global_shuffle"] = self.global_shuffle
         args["partitions"] = self.partitions
@@ -2272,8 +2277,11 @@ class MindDataset(SourceDataset):
         Return:
             Number, number of batches.
         """
-
-        num_rows = MindRecordOp.get_num_rows(self.dataset_file, self.sampler)
+        if self.load_dataset:
+            dataset_file = [self.dataset_file]
+        else:
+            dataset_file = self.dataset_file
+        num_rows = MindRecordOp.get_num_rows(dataset_file, self.load_dataset, self.sampler)
         if self.partitions is not None and self.partitions[0] > 0:
             if num_rows % self.partitions[0] == 0:
                 num_rows = num_rows // self.partitions[0]

mindspore/dataset/engine/validators.py

@@ -529,8 +529,11 @@ def check_minddataset(method):
         dataset_file = param_dict.get('dataset_file')
         if dataset_file is None:
             raise ValueError("dataset_file is not provided.")
-        check_dataset_file(dataset_file)
-
+        if isinstance(dataset_file, list):
+            for f in dataset_file:
+                check_dataset_file(f)
+        else:
+            check_dataset_file(dataset_file)
         check_param_type(nreq_param_int, param_dict, int)
 
         check_param_type(nreq_param_list, param_dict, list)

mindspore/mindrecord/filereader.py

@@ -28,7 +28,7 @@ class FileReader:
     Class to read MindRecord File series.
 
     Args:
-       file_name (str): File name of MindRecord File.
+       file_name (str, list[str]): One of MindRecord File or file list.
        num_consumer(int, optional): Number of consumer threads which load data to memory (default=4).
            It should not be smaller than 1 or larger than the number of CPU.
        columns (list[str], optional): List of fields which correspond data would be read (default=None).
@@ -38,8 +38,11 @@ class FileReader:
         ParamValueError: If file_name, num_consumer or columns is invalid.
     """
     def __init__(self, file_name, num_consumer=4, columns=None, operator=None):
-        check_filename(file_name)
-        self._file_name = file_name
+        if isinstance(file_name, list):
+            for f in file_name:
+                check_filename(f)
+        else:
+            check_filename(file_name)
 
         if num_consumer is not None:
             if isinstance(num_consumer, int):

mindspore/mindrecord/mindpage.py

@@ -28,7 +28,7 @@ class MindPage:
     Class to read MindRecord File series in pagination.
 
     Args:
-        file_name (str): File name of MindRecord File.
+        file_name (str): One of MindRecord File or file list.
         num_consumer(int, optional): Number of consumer threads which load data to memory (default=4).
             It should not be smaller than 1 or larger than the number of CPU.
 
@@ -37,8 +37,11 @@ class MindPage:
         MRMInitSegmentError: If failed to initialize ShardSegment.
     """
     def __init__(self, file_name, num_consumer=4):
-        check_filename(file_name)
-        self._file_name = file_name
+        if isinstance(file_name, list):
+            for f in file_name:
+                check_filename(f)
+        else:
+            check_filename(file_name)
 
         if num_consumer is not None:
             if isinstance(num_consumer, int):

mindspore/mindrecord/shardreader.py

@@ -35,7 +35,7 @@ class ShardReader:
         Open file and prepare to read MindRecord File.
 
         Args:
-           file_name (str): File name of MindRecord File.
+           file_name (str, list[str]): File names of MindRecord File.
            num_consumer (int): Number of worker threads which load data in parallel. Default: 4.
            columns (list[str]): List of fields which correspond data would be read.
            operator(int): Reserved parameter for operators. Default: None.
@@ -48,7 +48,12 @@ class ShardReader:
         """
         columns = columns if columns else []
         operator = operator if operator else []
-        ret = self._reader.open(file_name, num_consumer, columns, operator)
+        if isinstance(file_name, list):
+            load_dataset = False
+        else:
+            load_dataset = True
+            file_name = [file_name]
+        ret = self._reader.open(file_name, load_dataset, num_consumer, columns, operator)
         if ret != ms.MSRStatus.SUCCESS:
             logger.error("Failed to open {}.".format(file_name))
             raise MRMOpenError

mindspore/mindrecord/shardsegment.py

@@ -40,7 +40,7 @@ class ShardSegment:
         Initialize the ShardSegment.
 
         Args:
-            file_name (str): File name of MindRecord File.
+            file_name (str, list[str]): File names of MindRecord File.
             num_consumer (int): Number of worker threads which load data in parallel. Default: 4.
             columns (list[str]): List of fields which correspond data would be read.
             operator(int): Reserved parameter for operators. Default: None.
@@ -53,7 +53,12 @@ class ShardSegment:
         """
         self._columns = columns if columns else []
         operator = operator if operator else []
-        ret = self._segment.open(file_name, num_consumer, self._columns, operator)
+        if isinstance(file_name, list):
+            load_dataset = False
+        else:
+            load_dataset = True
+            file_name = [file_name]
+        ret = self._segment.open(file_name, load_dataset, num_consumer, self._columns, operator)
         if ret != SUCCESS:
             logger.error("Failed to open {}.".format(file_name))
             raise MRMOpenError

tests/ut/cpp/dataset/mind_record_op_test.cc

@@ -62,7 +62,8 @@ TEST_F(MindDataTestMindRecordOp, TestMindRecordBasic) {
 
   std::shared_ptr<MindRecordOp> my_mindrecord_op;
   MindRecordOp::Builder builder;
-  builder.SetDatasetFile(mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0")
+  builder.SetDatasetFile({mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0"})
+      .SetLoadDataset(true)
       .SetRowsPerBuffer(3)
       .SetNumMindRecordWorkers(4)
       .SetColumnsToLoad(column_list);
@@ -132,7 +133,8 @@ TEST_F(MindDataTestMindRecordOp, TestMindRecordSample) {
 
   std::shared_ptr<MindRecordOp> my_mindrecord_op;
   MindRecordOp::Builder builder;
-  builder.SetDatasetFile(mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0")
+  builder.SetDatasetFile({mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0"})
+      .SetLoadDataset(true)
       .SetRowsPerBuffer(3)
       .SetNumMindRecordWorkers(4)
       .SetColumnsToLoad(column_list)
@@ -203,7 +205,8 @@ TEST_F(MindDataTestMindRecordOp, TestMindRecordShuffle) {
 
   std::shared_ptr<MindRecordOp> my_mindrecord_op;
   MindRecordOp::Builder builder;
-  builder.SetDatasetFile(mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0")
+  builder.SetDatasetFile({mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0"})
+      .SetLoadDataset(true)
       .SetRowsPerBuffer(3)
       .SetNumMindRecordWorkers(4)
       .SetColumnsToLoad(column_list)
@@ -277,7 +280,8 @@ TEST_F(MindDataTestMindRecordOp, TestMindRecordCategory) {
 
   std::shared_ptr<MindRecordOp> my_mindrecord_op;
   MindRecordOp::Builder builder;
-  builder.SetDatasetFile(mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0")
+  builder.SetDatasetFile({mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0"})
+      .SetLoadDataset(true)
       .SetRowsPerBuffer(3)
       .SetNumMindRecordWorkers(4)
       .SetColumnsToLoad(column_list)
@@ -345,7 +349,8 @@ TEST_F(MindDataTestMindRecordOp, TestMindRecordRepeat) {
 
   std::shared_ptr<MindRecordOp> my_mindrecord_op;
   MindRecordOp::Builder builder;
-  builder.SetDatasetFile(mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0")
+  builder.SetDatasetFile({mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0"})
+      .SetLoadDataset(true)
       .SetRowsPerBuffer(3)
       .SetNumMindRecordWorkers(4)
       .SetColumnsToLoad(column_list);
@@ -426,7 +431,8 @@ TEST_F(MindDataTestMindRecordOp, TestMindRecordBlockReaderRepeat) {
 
   std::shared_ptr<MindRecordOp> my_mindrecord_op;
   MindRecordOp::Builder builder;
-  builder.SetDatasetFile(mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0")
+  builder.SetDatasetFile({mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0"})
+      .SetLoadDataset(true)
       .SetRowsPerBuffer(3)
       .SetNumMindRecordWorkers(4)
       .SetBlockReader()
@@ -507,7 +513,8 @@ TEST_F(MindDataTestMindRecordOp, TestMindRecordInvalidColumnList) {
 
   std::shared_ptr<MindRecordOp> my_mindrecord_op;
   MindRecordOp::Builder builder;
-  builder.SetDatasetFile(mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0")
+  builder.SetDatasetFile({mindrecord_root_path_ + "/testMindDataSet/testImageNetData/imagenet.mindrecord0"})
+      .SetLoadDataset(true)
       .SetRowsPerBuffer(3)
       .SetNumMindRecordWorkers(4)
       .SetColumnsToLoad(column_list);

tests/ut/cpp/mindrecord/ut_shard_operator_test.cc

@@ -63,7 +63,7 @@ TEST_F(TestShardOperator, TestShardSampleBasic) {
   std::vector<std::shared_ptr<ShardOperator>> ops;
   ops.push_back(std::make_shared<ShardSample>(kSampleCount));
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -89,7 +89,7 @@ TEST_F(TestShardOperator, TestShardSampleWrongNumber) {
   ops.push_back(std::make_shared<ShardSample>(kNum, kDen));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -115,7 +115,7 @@ TEST_F(TestShardOperator, TestShardSampleRatio) {
   ops.push_back(std::make_shared<ShardSample>(kNum, kDen));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -144,7 +144,7 @@ TEST_F(TestShardOperator, TestShardSamplePartition) {
   ASSERT_TRUE(partitions.second == 2);
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -168,7 +168,7 @@ TEST_F(TestShardOperator, TestShardPkSamplerBasic) {
   ops.push_back(std::make_shared<ShardPkSample>("label", 2));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name},true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -193,7 +193,7 @@ TEST_F(TestShardOperator, TestShardPkSamplerNumClass) {
   ops.push_back(std::make_shared<ShardPkSample>("label", 2, 3, 0));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name},true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -223,7 +223,7 @@ TEST_F(TestShardOperator, TestShardCategory) {
   ops.push_back(std::make_shared<ShardCategory>(categories));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -254,7 +254,7 @@ TEST_F(TestShardOperator, TestShardShuffle) {
   ops.push_back(std::make_shared<ShardShuffle>(1));
 
   ShardReader dataset;
-  dataset.Open(file_name, 16, column_list, ops);
+  dataset.Open({file_name}, true, 16, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -279,7 +279,7 @@ TEST_F(TestShardOperator, TestShardSampleShuffle) {
   ops.push_back(std::make_shared<ShardShuffle>(1));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -306,7 +306,7 @@ TEST_F(TestShardOperator, TestShardShuffleSample) {
   ops.push_back(std::make_shared<ShardSample>(kSampleSize));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true,  4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -333,7 +333,7 @@ TEST_F(TestShardOperator, TestShardSampleShuffleSample) {
   ops.push_back(std::make_shared<ShardSample>(35));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -357,11 +357,11 @@ TEST_F(TestShardOperator, TestShardShuffleCompare) {
   ops.push_back(std::make_shared<ShardShuffle>(1));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true,  4, column_list, ops);
   dataset.Launch();
 
   ShardReader compare_dataset;
-  compare_dataset.Open(file_name, 4, column_list);
+  compare_dataset.Open({file_name},true, 4, column_list);
   compare_dataset.Launch();
 
   int i = 0;
@@ -396,7 +396,7 @@ TEST_F(TestShardOperator, TestShardCategoryShuffle1) {
   ops.push_back(std::make_shared<ShardShuffle>(21));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -430,7 +430,7 @@ TEST_F(TestShardOperator, TestShardCategoryShuffle2) {
   ops.push_back(std::make_shared<ShardCategory>(categories));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -464,7 +464,7 @@ TEST_F(TestShardOperator, TestShardCategorySample) {
   ops.push_back(std::make_shared<ShardCategory>(categories));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name},true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;
@@ -502,7 +502,7 @@ TEST_F(TestShardOperator, TestShardCategorySampleShuffle) {
   ops.push_back(std::make_shared<ShardShuffle>(100));
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   int i = 0;

tests/ut/cpp/mindrecord/ut_shard_reader_test.cc

@@ -55,7 +55,7 @@ TEST_F(TestShardReader, TestShardReaderGeneral) {
   auto column_list = std::vector<std::string>{"file_name"};
 
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list);
+  dataset.Open({file_name}, true, 4, column_list);
   dataset.Launch();
 
   while (true) {
@@ -78,7 +78,7 @@ TEST_F(TestShardReader, TestShardReaderSample) {
   std::vector<std::shared_ptr<ShardOperator>> ops;
   ops.push_back(std::make_shared<ShardSample>(17));
   ShardReader dataset;
-  dataset.Open(file_name, 4, column_list, ops);
+  dataset.Open({file_name}, true, 4, column_list, ops);
   dataset.Launch();
 
   while (true) {
@@ -103,7 +103,7 @@ TEST_F(TestShardReader, TestShardReaderBlock) {
   ops.push_back(std::make_shared<ShardSample>(3));
   ShardReader dataset;
   const bool kBlockReader = true;
-  dataset.Open(file_name, 4, column_list, ops, kBlockReader);
+  dataset.Open({file_name}, true, 4, column_list, ops, kBlockReader);
   dataset.Launch();
 
   while (true) {
@@ -123,7 +123,7 @@ TEST_F(TestShardReader, TestShardReaderEasy) {
   MS_LOG(INFO) << FormatInfo("Test read imageNet");
   std::string file_name = "./imagenet.shard01";
   ShardReader dataset;
-  dataset.Open(file_name);
+  dataset.Open({file_name}, true);
   dataset.Launch();
 
   while (true) {
@@ -143,7 +143,7 @@ TEST_F(TestShardReader, TestShardReaderColumnNotInIndex) {
   std::string file_name = "./imagenet.shard01";
   auto column_list = std::vector<std::string>{"label"};
   ShardReader dataset;
-  MSRStatus ret = dataset.Open(file_name, 4, column_list);
+  MSRStatus ret = dataset.Open({file_name}, true,  4, column_list);
   ASSERT_EQ(ret, SUCCESS);
   dataset.Launch();
 
@@ -164,7 +164,7 @@ TEST_F(TestShardReader, TestShardReaderColumnNotInSchema) {
   std::string file_name = "./imagenet.shard01";
   auto column_list = std::vector<std::string>{"file_namex"};
   ShardReader dataset;
-  MSRStatus ret = dataset.Open(file_name, 4, column_list);
+  MSRStatus ret = dataset.Open({file_name}, true, 4, column_list);
   ASSERT_EQ(ret, ILLEGAL_COLUMN_LIST);
 }
 
@@ -172,7 +172,7 @@ TEST_F(TestShardReader, TestShardVersion) {
   MS_LOG(INFO) << FormatInfo("Test shard version");
   std::string file_name = "./imagenet.shard01";
   ShardReader dataset;
-  MSRStatus ret = dataset.Open(file_name, 4);
+  MSRStatus ret = dataset.Open({file_name}, true,  4);
   ASSERT_EQ(ret, SUCCESS);
   dataset.Launch();
 
@@ -195,7 +195,7 @@ TEST_F(TestShardReader, TestShardReaderDir) {
   auto column_list = std::vector<std::string>{"file_name"};
 
   ShardReader dataset;
-  MSRStatus ret = dataset.Open(file_name, 4, column_list);
+  MSRStatus ret = dataset.Open({file_name}, true,  4, column_list);
   ASSERT_EQ(ret, FAILED);
 }
 
@@ -205,7 +205,7 @@ TEST_F(TestShardReader, TestShardReaderConsumer) {
   auto column_list = std::vector<std::string>{"file_name"};
 
   ShardReader dataset;
-  dataset.Open(file_name, -481565535, column_list);
+  dataset.Open({file_name}, true,  -481565535, column_list);
   dataset.Launch();
 
   while (true) {

tests/ut/cpp/mindrecord/ut_shard_segment_test.cc

@@ -59,7 +59,7 @@ TEST_F(TestShardSegment, TestShardSegment) {
   std::string file_name = "./imagenet.shard01";
 
   ShardSegment dataset;
-  dataset.Open(file_name, 4);
+  dataset.Open({file_name}, true, 4);
 
   auto x = dataset.GetCategoryFields();
   for (const auto &fields : x.second) {
@@ -97,7 +97,7 @@ TEST_F(TestShardSegment, TestReadAtPageByNameOfCategoryName) {
   std::string file_name = "./imagenet.shard01";
 
   ShardSegment dataset;
-  dataset.Open(file_name, 4);
+  dataset.Open({file_name}, true, 4);
 
   auto x = dataset.GetCategoryFields();
   for (const auto &fields : x.second) {
@@ -121,7 +121,7 @@ TEST_F(TestShardSegment, TestReadAtPageByIdOfCategoryId) {
   std::string file_name = "./imagenet.shard01";
 
   ShardSegment dataset;
-  dataset.Open(file_name, 4);
+  dataset.Open({file_name}, true,  4);
 
   auto x = dataset.GetCategoryFields();
   for (const auto &fields : x.second) {
@@ -143,7 +143,7 @@ TEST_F(TestShardSegment, TestReadAtPageByIdOfPageNo) {
   std::string file_name = "./imagenet.shard01";
 
   ShardSegment dataset;
-  dataset.Open(file_name, 4);
+  dataset.Open({file_name}, true, 4);
 
   auto x = dataset.GetCategoryFields();
   for (const auto &fields : x.second) {
@@ -165,7 +165,7 @@ TEST_F(TestShardSegment, TestReadAtPageByIdOfPageRows) {
   std::string file_name = "./imagenet.shard01";
 
   ShardSegment dataset;
-  dataset.Open(file_name, 4);
+  dataset.Open({file_name}, true, 4);
 
   auto x = dataset.GetCategoryFields();
   for (const auto &fields : x.second) {

tests/ut/cpp/mindrecord/ut_shard_writer_test.cc

@@ -60,7 +60,7 @@ TEST_F(TestShardWriter, TestShardWriterOneSample) {
   std::string filename = "./OneSample.shard01";
 
   ShardReader dataset;
-  MSRStatus ret = dataset.Open(filename, 4);
+  MSRStatus ret = dataset.Open({filename}, true, 4);
   ASSERT_EQ(ret, SUCCESS);
   dataset.Launch();
 
@@ -756,7 +756,7 @@ TEST_F(TestShardWriter, TestShardReaderStringAndNumberColumnInIndex) {
   filename = "./imagenet.shard01";
   auto column_list = std::vector<std::string>{"label", "file_name", "data"};
   ShardReader dataset;
-  MSRStatus ret = dataset.Open(filename, 4, column_list);
+  MSRStatus ret = dataset.Open({filename}, true, 4, column_list);
   ASSERT_EQ(ret, SUCCESS);
   dataset.Launch();
 
@@ -842,7 +842,7 @@ TEST_F(TestShardWriter, TestShardNoBlob) {
   filename = "./imagenet.shard01";
   auto column_list = std::vector<std::string>{"label", "file_name"};
   ShardReader dataset;
-  MSRStatus ret = dataset.Open(filename, 4, column_list);
+  MSRStatus ret = dataset.Open({filename}, true, 4, column_list);
   ASSERT_EQ(ret, SUCCESS);
   dataset.Launch();
 
@@ -936,7 +936,7 @@ TEST_F(TestShardWriter, TestShardReaderStringAndNumberNotColumnInIndex) {
   filename = "./imagenet.shard01";
   auto column_list = std::vector<std::string>{"label", "data"};
   ShardReader dataset;
-  MSRStatus ret = dataset.Open(filename, 4, column_list);
+  MSRStatus ret = dataset.Open({filename}, true, 4, column_list);
   ASSERT_EQ(ret, SUCCESS);
   dataset.Launch();
 
@@ -1043,7 +1043,7 @@ TEST_F(TestShardWriter, TestShardWriter10Sample40Shard) {
 
   filename = "./TenSampleFortyShard.shard01";
   ShardReader dataset;
-  MSRStatus ret = dataset.Open(filename, 4);
+  MSRStatus ret = dataset.Open({filename}, true, 4);
   ASSERT_EQ(ret, SUCCESS);
   dataset.Launch();
 

tests/ut/python/dataset/test_minddataset.py

@@ -32,6 +32,8 @@ from mindspore.mindrecord import FileWriter
 
 FILES_NUM = 4
 CV_FILE_NAME = "../data/mindrecord/imagenet.mindrecord"
+CV1_FILE_NAME = "../data/mindrecord/imagenet1.mindrecord"
+CV2_FILE_NAME = "../data/mindrecord/imagenet2.mindrecord"
 CV_DIR_NAME = "../data/mindrecord/testImageNetData"
 NLP_FILE_NAME = "../data/mindrecord/aclImdb.mindrecord"
 NLP_FILE_POS = "../data/mindrecord/testAclImdbData/pos"
@@ -111,7 +113,6 @@ def test_cv_minddataset_writer_tutorial():
         os.remove("{}".format(x))
         os.remove("{}.db".format(x))
 
-
 def test_cv_minddataset_partition_tutorial(add_and_remove_cv_file):
     """tutorial for cv minddataset."""
     columns_list = ["data", "file_name", "label"]
@@ -247,6 +248,126 @@ def test_cv_minddataset_blockreader_some_field_not_in_index_tutorial(add_and_rem
     assert num_iter == 20
 
 
+def test_cv_minddataset_reader_file_list(add_and_remove_cv_file):
+    """tutorial for cv minderdataset."""
+    columns_list = ["data", "file_name", "label"]
+    num_readers = 4
+    data_set = ds.MindDataset([CV_FILE_NAME + str(x) for x in range(FILES_NUM)], columns_list, num_readers)
+    assert data_set.get_dataset_size() == 10
+    num_iter = 0
+    for item in data_set.create_dict_iterator():
+        logger.info("-------------- cv reader basic: {} ------------------------".format(num_iter))
+        logger.info("-------------- len(item[data]): {} ------------------------".format(len(item["data"])))
+        logger.info("-------------- item[data]: {} -----------------------------".format(item["data"]))
+        logger.info("-------------- item[file_name]: {} ------------------------".format(item["file_name"]))
+        logger.info("-------------- item[label]: {} ----------------------------".format(item["label"]))
+        num_iter += 1
+    assert num_iter == 10
+
+def test_cv_minddataset_reader_one_partition(add_and_remove_cv_file):
+    """tutorial for cv minderdataset."""
+    columns_list = ["data", "file_name", "label"]
+    num_readers = 4
+    data_set = ds.MindDataset([CV_FILE_NAME + "0"], columns_list, num_readers)
+    assert data_set.get_dataset_size() < 10
+    num_iter = 0
+    for item in data_set.create_dict_iterator():
+        logger.info("-------------- cv reader basic: {} ------------------------".format(num_iter))
+        logger.info("-------------- len(item[data]): {} ------------------------".format(len(item["data"])))
+        logger.info("-------------- item[data]: {} -----------------------------".format(item["data"]))
+        logger.info("-------------- item[file_name]: {} ------------------------".format(item["file_name"]))
+        logger.info("-------------- item[label]: {} ----------------------------".format(item["label"]))
+        num_iter += 1
+    assert num_iter < 10
+
+def test_cv_minddataset_reader_two_dataset(add_and_remove_cv_file):
+    """tutorial for cv minderdataset."""
+    if os.path.exists(CV1_FILE_NAME):
+        os.remove(CV1_FILE_NAME)
+    if os.path.exists("{}.db".format(CV1_FILE_NAME)):
+        os.remove("{}.db".format(CV1_FILE_NAME))
+    if os.path.exists(CV2_FILE_NAME):
+        os.remove(CV2_FILE_NAME)
+    if os.path.exists("{}.db".format(CV2_FILE_NAME)):
+        os.remove("{}.db".format(CV2_FILE_NAME))
+    writer = FileWriter(CV1_FILE_NAME, 1)
+    data = get_data(CV_DIR_NAME)
+    cv_schema_json = {"id": {"type": "int32"},
+                      "file_name": {"type": "string"},
+                      "label": {"type": "int32"},
+                      "data": {"type": "bytes"}}
+    writer.add_schema(cv_schema_json, "CV1_schema")
+    writer.add_index(["file_name", "label"])
+    writer.write_raw_data(data)
+    writer.commit()
+
+    writer = FileWriter(CV2_FILE_NAME, 1)
+    data = get_data(CV_DIR_NAME)
+    cv_schema_json = {"id": {"type": "int32"},
+                      "file_name": {"type": "string"},
+                      "label": {"type": "int32"},
+                      "data": {"type": "bytes"}}
+    writer.add_schema(cv_schema_json, "CV2_schema")
+    writer.add_index(["file_name", "label"])
+    writer.write_raw_data(data)
+    writer.commit()
+    columns_list = ["data", "file_name", "label"]
+    num_readers = 4
+    data_set = ds.MindDataset([CV_FILE_NAME + str(x) for x in range(FILES_NUM)] + [CV1_FILE_NAME, CV2_FILE_NAME], columns_list, num_readers)
+    assert data_set.get_dataset_size() == 30
+    num_iter = 0
+    for item in data_set.create_dict_iterator():
+        logger.info("-------------- cv reader basic: {} ------------------------".format(num_iter))
+        logger.info("-------------- len(item[data]): {} ------------------------".format(len(item["data"])))
+        logger.info("-------------- item[data]: {} -----------------------------".format(item["data"]))
+        logger.info("-------------- item[file_name]: {} ------------------------".format(item["file_name"]))
+        logger.info("-------------- item[label]: {} ----------------------------".format(item["label"]))
+        num_iter += 1
+    assert num_iter == 30
+    if os.path.exists(CV1_FILE_NAME):
+        os.remove(CV1_FILE_NAME)
+    if os.path.exists("{}.db".format(CV1_FILE_NAME)):
+        os.remove("{}.db".format(CV1_FILE_NAME))
+    if os.path.exists(CV2_FILE_NAME):
+        os.remove(CV2_FILE_NAME)
+    if os.path.exists("{}.db".format(CV2_FILE_NAME)):
+        os.remove("{}.db".format(CV2_FILE_NAME))
+        
+def test_cv_minddataset_reader_two_dataset_partition(add_and_remove_cv_file):
+    paths = ["{}{}".format(CV1_FILE_NAME, str(x).rjust(1, '0'))
+             for x in range(FILES_NUM)]
+    for x in paths:
+        os.remove("{}".format(x)) if os.path.exists("{}".format(x)) else None
+        os.remove("{}.db".format(x)) if os.path.exists("{}.db".format(x)) else None
+    writer = FileWriter(CV1_FILE_NAME, FILES_NUM)
+    data = get_data(CV_DIR_NAME)
+    cv_schema_json = {"id": {"type": "int32"},
+                      "file_name": {"type": "string"},
+                      "label": {"type": "int32"},
+                      "data": {"type": "bytes"}}
+    writer.add_schema(cv_schema_json, "CV1_schema")
+    writer.add_index(["file_name", "label"])
+    writer.write_raw_data(data)
+    writer.commit()
+
+    columns_list = ["data", "file_name", "label"]
+    num_readers = 4
+    data_set = ds.MindDataset([CV_FILE_NAME + str(x) for x in range(2)] + [CV1_FILE_NAME + str(x) for x in range(2, 4)], columns_list, num_readers)
+    assert data_set.get_dataset_size() < 20
+    num_iter = 0
+    for item in data_set.create_dict_iterator():
+        logger.info("-------------- cv reader basic: {} ------------------------".format(num_iter))
+        logger.info("-------------- len(item[data]): {} ------------------------".format(len(item["data"])))
+        logger.info("-------------- item[data]: {} -----------------------------".format(item["data"]))
+        logger.info("-------------- item[file_name]: {} ------------------------".format(item["file_name"]))
+        logger.info("-------------- item[label]: {} ----------------------------".format(item["label"]))
+        num_iter += 1
+    assert num_iter < 20
+    for x in paths:
+        os.remove("{}".format(x))
+        os.remove("{}.db".format(x))
+
+
 def test_cv_minddataset_reader_basic_tutorial(add_and_remove_cv_file):
     """tutorial for cv minderdataset."""
     columns_list = ["data", "file_name", "label"]

tests/ut/python/dataset/test_minddataset_exception.py

@@ -22,6 +22,7 @@ import mindspore.dataset as ds
 from mindspore.mindrecord import FileWriter
 
 CV_FILE_NAME = "./imagenet.mindrecord"
+CV1_FILE_NAME = "./imagenet1.mindrecord"
 
 
 def create_cv_mindrecord(files_num):
@@ -37,6 +38,31 @@ def create_cv_mindrecord(files_num):
     writer.commit()
 
 
+def create_diff_schema_cv_mindrecord(files_num):
+    """tutorial for cv dataset writer."""
+    os.remove(CV1_FILE_NAME) if os.path.exists(CV1_FILE_NAME) else None
+    os.remove("{}.db".format(CV1_FILE_NAME)) if os.path.exists("{}.db".format(CV1_FILE_NAME)) else None
+    writer = FileWriter(CV1_FILE_NAME, files_num)
+    cv_schema_json = {"file_name_1": {"type": "string"}, "label": {"type": "int32"}, "data": {"type": "bytes"}}
+    data = [{"file_name_1": "001.jpg", "label": 43, "data": bytes('0xffsafdafda', encoding='utf-8')}]
+    writer.add_schema(cv_schema_json, "img_schema")
+    writer.add_index(["file_name_1", "label"])
+    writer.write_raw_data(data)
+    writer.commit()
+
+def create_diff_page_size_cv_mindrecord(files_num):
+    """tutorial for cv dataset writer."""
+    os.remove(CV1_FILE_NAME) if os.path.exists(CV1_FILE_NAME) else None
+    os.remove("{}.db".format(CV1_FILE_NAME)) if os.path.exists("{}.db".format(CV1_FILE_NAME)) else None
+    writer = FileWriter(CV1_FILE_NAME, files_num)
+    writer.set_page_size(1<< 26) #64MB
+    cv_schema_json = {"file_name": {"type": "string"}, "label": {"type": "int32"}, "data": {"type": "bytes"}}
+    data = [{"file_name": "001.jpg", "label": 43, "data": bytes('0xffsafdafda', encoding='utf-8')}]
+    writer.add_schema(cv_schema_json, "img_schema")
+    writer.add_index(["file_name", "label"])
+    writer.write_raw_data(data)
+    writer.commit()
+
 def test_cv_lack_json():
     """tutorial for cv minderdataset."""
     create_cv_mindrecord(1)
@@ -111,3 +137,34 @@ def test_cv_minddataset_pk_sample_exclusive_shuffle():
     os.remove(CV_FILE_NAME)
     os.remove("{}.db".format(CV_FILE_NAME))
 
+def test_cv_minddataset_reader_different_schema():
+    create_cv_mindrecord(1)
+    create_diff_schema_cv_mindrecord(1)
+    columns_list = ["data", "label"]
+    num_readers = 4
+    with pytest.raises(Exception, match="MindRecordOp init failed"):
+        data_set = ds.MindDataset([CV_FILE_NAME, CV1_FILE_NAME], columns_list,
+                num_readers)
+        num_iter = 0
+        for item in data_set.create_dict_iterator():
+            num_iter += 1
+    os.remove(CV_FILE_NAME)
+    os.remove("{}.db".format(CV_FILE_NAME))
+    os.remove(CV1_FILE_NAME)
+    os.remove("{}.db".format(CV1_FILE_NAME))
+
+def test_cv_minddataset_reader_different_page_size():
+    create_cv_mindrecord(1)
+    create_diff_page_size_cv_mindrecord(1)
+    columns_list = ["data", "label"]
+    num_readers = 4
+    with pytest.raises(Exception, match="MindRecordOp init failed"):
+        data_set = ds.MindDataset([CV_FILE_NAME, CV1_FILE_NAME], columns_list,
+                num_readers)
+        num_iter = 0
+        for item in data_set.create_dict_iterator():
+            num_iter += 1
+    os.remove(CV_FILE_NAME)
+    os.remove("{}.db".format(CV_FILE_NAME))
+    os.remove(CV1_FILE_NAME)
+    os.remove("{}.db".format(CV1_FILE_NAME))

tests/ut/python/mindrecord/test_mindrecord_base.py

@@ -202,6 +202,16 @@ def test_cv_file_reader_tutorial():
     assert count == 10
     reader.close()
 
+def test_cv_file_reader_file_list():
+    """tutorial for cv file partial reader."""
+    reader = FileReader([CV_FILE_NAME + str(x) for x in range(FILES_NUM)])
+    count = 0
+    for index, x in enumerate(reader.get_next()):
+        assert len(x) == 3
+        count = count + 1
+        logger.info("#item{}: {}".format(index, x))
+    assert count == 10
+
 def test_cv_file_reader_partial_tutorial():
     """tutorial for cv file partial reader."""
     reader = FileReader(CV_FILE_NAME + "0")