| """ |
| Copyright 2020 The Magma Authors. |
| |
| This source code is licensed under the BSD-style license found in the |
| LICENSE file in the root directory of this source tree. |
| |
| 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. |
| """ |
| |
| import codecs |
| import os |
| |
| |
| def write_to_file_atomically(filename, value, temp_filename=None): |
| """ |
| Atomically write to a file by first writing the value to a temp file, then |
| moving that temp file to the specified file location. |
| |
| This function will create all directories necessary for the file as well. |
| |
| Args: |
| filename: full path to the file to write to |
| value: value to write to the file |
| temp_filename: requested path of the intermediate temp file |
| mode: mode to open the file |
| """ |
| os.makedirs(os.path.dirname(filename), exist_ok=True) |
| temp_filename = temp_filename or '{}.tmp'.format(filename) |
| with codecs.open(temp_filename, 'w', encoding='utf8') as f: |
| f.write(value) |
| f.flush() |
| os.fsync(f.fileno()) |
| os.replace(temp_filename, filename) |