add BORG_USE_CHUNKS_ARCHIVE

borgmatic/borg/environment.py

@@ -79,6 +79,9 @@ def make_environment(config):
         os.set_inheritable(read_file_descriptor, True)
         environment['BORG_PASSPHRASE_FD'] = str(read_file_descriptor)
 
+    if 'use_chunks_archive' in config:
+        environment['BORG_USE_CHUNKS_ARCHIVE'] = 'yes' if config.get('use_chunks_archive') else 'no'
+
     for (
         option_name,
         environment_variable_name,

borgmatic/config/schema.yaml

@@ -389,6 +389,13 @@ properties:
             Path for Borg cache files. Defaults to
             $borg_base_directory/.cache/borg
         example: /path/to/base/cache
+    use_chunks_archive:
+        type: boolean
+        description: |
+            Enables or disables the use of chunks.archive.d for faster cache
+            resyncs in Borg. If true, value is set to "yes" (default) else
+            it's set to "no", reducing disk usage but slowing resyncs.
+        default: true
     borg_files_cache_ttl:
         type: integer
         description: |

tests/unit/borg/test_environment.py

@@ -170,3 +170,13 @@ def test_make_environment_with_integer_variable_value():
     environment = module.make_environment({'borg_files_cache_ttl': 40})
 
     assert environment.get('BORG_FILES_CACHE_TTL') == '40'
+
+
+def test_make_environment_with_use_chunks_archive_should_set_correct_environment_value():
+    flexmock(module.os).should_receive('environ').and_return({'USER': 'root'})
+
+    environment = module.make_environment({'use_chunks_archive': True})
+    assert environment.get('BORG_USE_CHUNKS_ARCHIVE') == 'yes'
+
+    environment = module.make_environment({'use_chunks_archive': False})
+    assert environment.get('BORG_USE_CHUNKS_ARCHIVE') == 'no'