[MXNET-128] added load from buffer functions

cpp-package/include/mxnet-cpp/ndarray.h

@@ -398,6 +398,32 @@ class NDArray {
   */
   static std::vector<NDArray> LoadToList(const std::string &file_name);
   /*!
+  * \brief Load NDArrays from buffer.
+  * \param buffer Pointer to buffer. (ie contents of param file)
+  * \param size Size of buffer
+  * \param array_list a list of NDArrays returned, do not fill the list if
+  * nullptr is given.
+  * \param array_map a map from names to NDArrays returned, do not fill the map
+  * if nullptr is given or no names is stored in binary file.
+  */
+  static void LoadFromBuffer(const void *buffer, size_t size,
+                   std::vector<NDArray> *array_list = nullptr,
+                   std::map<std::string, NDArray> *array_map = nullptr);
+  /*!
+  * \brief Load map of NDArrays from buffer.
+  * \param buffer Pointer to buffer. (ie contents of param file)
+  * \param size Size of buffer
+  * \return a list of NDArrays.
+  */
+  static std::map<std::string, NDArray> LoadFromBufferToMap(const void *buffer, size_t size);
+  /*!
+  * \brief Load list of NDArrays from buffer.
+  * \param buffer Pointer to buffer. (ie contents of param file)
+  * \param size Size of buffer
+  * \return a map from names to NDArrays.
+  */
+  static std::vector<NDArray> LoadFromBufferToList(const void *buffer, size_t size);
+  /*!
   * \brief save a map of string->NDArray to binary file.
   * \param file_name name of the binary file.
   * \param array_map a map from names to NDArrays.

cpp-package/include/mxnet-cpp/ndarray.hpp

@@ -255,6 +255,7 @@ inline void NDArray::Load(const std::string &file_name,
                          &out_names),
            0);
   if (array_list != nullptr) {
+    array_list->reserve(out_size);
     for (mx_uint i = 0; i < out_size; ++i) {
       array_list->push_back(NDArray(out_arr[i]));
     }
@@ -291,6 +292,60 @@ inline std::vector<NDArray> NDArray::LoadToList(const std::string &file_name) {
   CHECK_EQ(MXNDArrayLoad(file_name.c_str(), &out_size, &out_arr, &out_name_size,
                          &out_names),
            0);
+  array_list.reserve(out_size);
+  for (mx_uint i = 0; i < out_size; ++i) {
+    array_list.push_back(NDArray(out_arr[i]));
+  }
+  return array_list;
+}
+inline void NDArray::LoadFromBuffer(const void *buffer, size_t size,
+                          std::vector<NDArray> *array_list,
+                          std::map<std::string, NDArray> *array_map) {
+  mx_uint out_size, out_name_size;
+  NDArrayHandle *out_arr;
+  const char **out_names;
+  CHECK_EQ(MXNDArrayLoadFromBuffer(buffer, size, &out_size, &out_arr, &out_name_size,
+                         &out_names),
+           0);
+  if (array_list != nullptr) {
+    array_list->reserve(out_size);
+    for (mx_uint i = 0; i < out_size; ++i) {
+      array_list->push_back(NDArray(out_arr[i]));
+    }
+  }
+  if (array_map != nullptr && out_name_size > 0) {
+    CHECK_EQ(out_name_size, out_size);
+    for (mx_uint i = 0; i < out_size; ++i) {
+      (*array_map)[out_names[i]] = NDArray(out_arr[i]);
+    }
+  }
+}
+inline std::map<std::string, NDArray> NDArray::LoadFromBufferToMap(
+    const void *buffer, size_t size) {
+  std::map<std::string, NDArray> array_map;
+  mx_uint out_size, out_name_size;
+  NDArrayHandle *out_arr;
+  const char **out_names;
+  CHECK_EQ(MXNDArrayLoadFromBuffer(buffer, size, &out_size, &out_arr, &out_name_size,
+                         &out_names),
+           0);
+  if (out_name_size > 0) {
+    CHECK_EQ(out_name_size, out_size);
+    for (mx_uint i = 0; i < out_size; ++i) {
+      array_map[out_names[i]] = NDArray(out_arr[i]);
+    }
+  }
+  return array_map;
+}
+inline std::vector<NDArray> NDArray::LoadFromBufferToList(const void *buffer, size_t size) {
+  std::vector<NDArray> array_list;
+  mx_uint out_size, out_name_size;
+  NDArrayHandle *out_arr;
+  const char **out_names;
+  CHECK_EQ(MXNDArrayLoadFromBuffer(buffer, size, &out_size, &out_arr, &out_name_size,
+                         &out_names),
+           0);
+  array_list.reserve(out_size);
   for (mx_uint i = 0; i < out_size; ++i) {
     array_list.push_back(NDArray(out_arr[i]));
   }