Allow aborting a running BAT Pack operation

blender_cloud/flamenco/bat_interface.py

@@ -2,6 +2,7 @@
 
 import asyncio
 import logging
+import threading
 import typing
 import pathlib
 
@@ -14,6 +15,9 @@ import bpy
 
 log = logging.getLogger(__name__)
 
+_running_packer = None  # type: pack.Packer
+_packer_lock = threading.RLock()
+
 
 class BatProgress(progress.Callback):
     """Report progress of BAT Packing to the UI.
@@ -30,10 +34,20 @@ class BatProgress(progress.Callback):
 
     def txt(self, msg: str):
         """Set a text in a thread-safe way."""
+
         async def set_text():
             self.wm.flamenco_status_txt = msg
+
         asyncio.run_coroutine_threadsafe(set_text(), loop=self.loop)
 
+    def status(self, status: str):
+        """Set the flamenco_status property in a thread-safe way."""
+
+        async def set_status():
+            self.wm.flamenco_status = status
+
+        asyncio.run_coroutine_threadsafe(set_status(), loop=self.loop)
+
     def pack_start(self) -> None:
         self.txt('Starting BAT Pack operation')
 
@@ -45,6 +59,10 @@ class BatProgress(progress.Callback):
         else:
             self.txt('Pack of %s done' % output_blendfile.name)
 
+    def pack_aborted(self):
+        self.txt('Aborted')
+        self.status('ABORTED')
+
     def trace_blendfile(self, filename: pathlib.Path) -> None:
         """Called for every blendfile opened when tracing dependencies."""
         self.txt('Inspecting %s' % filename.name)
@@ -71,26 +89,29 @@ class BatProgress(progress.Callback):
         pass
 
 
-async def bat_copy(context,
-                   base_blendfile: pathlib.Path,
-                   project: pathlib.Path,
-                   target: pathlib.Path,
-                   exclusion_filter: str) -> typing.Tuple[pathlib.Path, typing.Set[pathlib.Path]]:
+async def copy(context,
+               base_blendfile: pathlib.Path,
+               project: pathlib.Path,
+               target: pathlib.Path,
+               exclusion_filter: str) -> typing.Tuple[pathlib.Path, typing.Set[pathlib.Path]]:
     """Use BAT🦇 to copy the given file and dependencies to the target location.
 
     :raises: FileTransferError if a file couldn't be transferred.
     :returns: the path of the packed blend file, and a set of missing sources.
     """
+    global _running_packer
 
     loop = asyncio.get_event_loop()
 
     wm = bpy.context.window_manager
 
     with pack.Packer(base_blendfile, project, target) as packer:
-        if exclusion_filter:
-            packer.exclude(*exclusion_filter.split())
+        with _packer_lock:
+            if exclusion_filter:
+                packer.exclude(*exclusion_filter.split())
 
-        packer.progress_cb = BatProgress(context)
+            packer.progress_cb = BatProgress(context)
+            _running_packer = packer
 
         log.debug('awaiting strategise')
         wm.flamenco_status = 'INVESTIGATING'
@@ -103,4 +124,21 @@ async def bat_copy(context,
         log.debug('done')
         wm.flamenco_status = 'DONE'
 
+    with _packer_lock:
+        _running_packer = None
+
     return packer.output_path, packer.missing_files
+
+
+def abort() -> None:
+    """Abort a running copy() call.
+
+    No-op when there is no running copy(). Can be called from any thread.
+    """
+
+    with _packer_lock:
+        if _running_packer is None:
+            log.debug('No running packer, ignoring call to bat_abort()')
+            return
+        log.info('Aborting running packer')
+        _running_packer.abort()