[cli/core/downloader] Add support for filtering downloaded files by prefix

legendary/cli.py

@@ -205,7 +205,8 @@ class LegendaryCLI:
                                                           override_manifest=args.override_manifest,
                                                           override_old_manifest=args.override_old_manifest,
                                                           override_base_url=args.override_base_url,
-                                                          platform_override=args.platform_override)
+                                                          platform_override=args.platform_override,
+                                                          file_prefix_filter=args.file_prefix)
 
         # game is either up to date or hasn't changed, so we have nothing to do
         if not analysis.dl_size:
@@ -380,6 +381,8 @@ def main():
                                 help='Set download manager and worker processes\' loglevel to debug')
     install_parser.add_argument('--platform', dest='platform_override', action='store', metavar='<Platform>',
                                 type=str, help='Platform override for download (disables install)')
+    install_parser.add_argument('--prefix-filter', dest='file_prefix', action='store', metavar='<prefix>',
+                                type=str, help='Only fetch files whose path starts with <prefix> (case insensitive)')
 
     launch_parser.add_argument('--offline', dest='offline', action='store_true',
                                default=False, help='Skip login and launch game without online authentication')

legendary/core.py

@@ -307,9 +307,10 @@ class LegendaryCore:
 
     def prepare_download(self, game: Game, base_game: Game = None, base_path: str = '',
                          status_q: Queue = None, max_shm: int = 0, max_workers: int = 0,
-                         force: bool = False, disable_patching: bool = False, game_folder: str = '',
-                         override_manifest: str = '', override_old_manifest: str = '',
-                         override_base_url: str = '', platform_override: str = '',
+                         force: bool = False, disable_patching: bool = False,
+                         game_folder: str = '', override_manifest: str = '',
+                         override_old_manifest: str = '', override_base_url: str = '',
+                         platform_override: str = '', file_prefix_filter: str = ''
                          ) -> (DLManager, AnalysisResult, ManifestMeta):
 
         # load old manifest
@@ -418,7 +419,8 @@ class LegendaryCore:
         dlm = DLManager(install_path, base_url, resume_file=resume_file, status_q=status_q,
                         max_shared_memory=max_shm * 1024 * 1024, max_workers=max_workers)
         anlres = dlm.run_analysis(manifest=new_manifest, old_manifest=old_manifest,
-                                  patch=not disable_patching, resume=not force)
+                                  patch=not disable_patching, resume=not force,
+                                  file_prefix_filter=file_prefix_filter)
 
         prereq = None
         if new_manifest.meta.prereq_ids:

legendary/downloader/manager.py

@@ -242,7 +242,7 @@ class DLManager(Process):
         self.log.info('Writer result handler quitting...')
 
     def run_analysis(self, manifest: Manifest, old_manifest: Manifest = None,
-                     patch=True, resume=True) -> AnalysisResult:
+                     patch=True, resume=True, file_prefix_filter=None) -> AnalysisResult:
         """
         Run analysis on manifest and old manifest (if not None) and return a result
         with a summary resources required in order to install the provided manifest.
@@ -251,9 +251,13 @@ class DLManager(Process):
         :param old_manifest: Old manifest to patch from (if applicable)
         :param patch: Patch instead of redownloading the entire file
         :param resume: Continue based on resume file if it exists
+        :param file_prefix_filter: Only download files that start with this prefix
         :return: AnalysisResult
         """
 
+        if file_prefix_filter:
+            file_prefix_filter = file_prefix_filter.lower()
+
         analysis_res = AnalysisResult()
         analysis_res.install_size = sum(fm.file_size for fm in manifest.file_manifest_list.elements)
         analysis_res.biggest_chunk = max(c.window_size for c in manifest.chunk_data_list.elements)
@@ -276,6 +280,14 @@ class DLManager(Process):
             except Exception as e:
                 self.log.warning(f'Reading resume file failed: {e!r}, continuing as normal...')
 
+        # if prefix has been set: mark all files that are not to be downloaded as unchanged (not removed)
+        if file_prefix_filter:
+            files_to_skip = set(i for i in mc.added | mc.changed if not i.lower().startswith(file_prefix_filter))
+            self.log.info(f'Found {len(files_to_skip)} files to skip based on prefix.')
+            mc.added -= files_to_skip
+            mc.changed -= files_to_skip
+            mc.unchanged |= files_to_skip
+
         if mc.removed:
             analysis_res.removed = len(mc.removed)
             self.log.debug(f'{analysis_res.removed} removed files')