zero copy for batch_get_tensor()

Signed-off-by: Cruz Zhao <CruzZhao@linux.alibaba.com>

Author: zxpdemonio

mooncake-integration/store/store_py.cpp

@@ -227,29 +227,18 @@ class MooncakeStorePyWrapper {
             py::gil_scoped_acquire acquire_gil;
             auto torch = torch_module();
 
+	    int i = 0;
             for (const auto &buffer_handle : buffer_handles) {
-                if (!buffer_handle) {
-                    results_list.append(py::none());
-                    continue;
-                }
-
-                auto total_length = buffer_handle->size();
-                if (total_length <= sizeof(TensorMetadata)) {
-                    LOG(ERROR) << "Invalid data format: insufficient data for "
-                                  "metadata";
-                    results_list.append(py::none());
-                    continue;
-                }
-
-                char *exported_data = new char[total_length];
-                if (!exported_data) {
-                    LOG(ERROR) << "Failed to allocate memory for tensor data";
+		uint64_t total_length = 0;
+                auto get_result = store_->get_allocated_internal(keys[i++], total_length);
+                if (!get_result) {
                     results_list.append(py::none());
                     continue;
                 }
 
-                memcpy(exported_data, buffer_handle->ptr(), total_length);
+		auto exported_data = *get_result;
 
+		// Copy metadata from buffer
                 TensorMetadata metadata;
                 memcpy(&metadata, exported_data, sizeof(TensorMetadata));