Added --compress option for 'bat pack' command

This compresses all packed Blend files. Other files, as well as already-
compressed Blend files, are left as-is.

blender_asset_tracer/pack/__init__.py

@@ -97,11 +97,14 @@ class Packer:
                  bfile: pathlib.Path,
                  project: pathlib.Path,
                  target: pathlib.Path,
-                 noop=False) -> None:
+                 *,
+                 noop=False,
+                 compress=False) -> None:
         self.blendfile = bfile
         self.project = project
         self.target = target
         self.noop = noop
+        self.compress = compress
         self._aborted = threading.Event()
         self._abort_lock = threading.RLock()
 
@@ -352,6 +355,9 @@ class Packer:
 
     def _create_file_transferer(self) -> transfer.FileTransferer:
         """Create a FileCopier(), can be overridden in a subclass."""
+
+        if self.compress:
+            return filesystem.CompressedFileCopier()
         return filesystem.FileCopier()
 
     def _start_file_transferrer(self):

blender_asset_tracer/pack/filesystem.py

@@ -22,6 +22,7 @@ import pathlib
 import shutil
 import typing
 
+from .. import compressor
 from . import transfer
 
 log = logging.getLogger(__name__)
@@ -81,9 +82,17 @@ class FileCopier(transfer.FileTransferer):
         if self.files_skipped:
             log.info('Skipped %d files', self.files_skipped)
 
+    def _move(self, srcpath: pathlib.Path, dstpath: pathlib.Path):
+        """Low-level file move"""
+        shutil.move(str(srcpath), str(dstpath))
+
+    def _copy(self, srcpath: pathlib.Path, dstpath: pathlib.Path):
+        """Low-level file copy"""
+        shutil.copy2(str(srcpath), str(dstpath))
+
     def move(self, srcpath: pathlib.Path, dstpath: pathlib.Path):
         s_stat = srcpath.stat()
-        shutil.move(str(srcpath), str(dstpath))
+        self._move(srcpath, dstpath)
 
         self.files_transferred += 1
         self.report_transferred(s_stat.st_size)
@@ -108,7 +117,7 @@ class FileCopier(transfer.FileTransferer):
                 return
 
         log.debug('Copying %s → %s', srcpath, dstpath)
-        shutil.copy2(str(srcpath), str(dstpath))
+        self._copy(srcpath, dstpath)
 
         self.already_copied.add((srcpath, dstpath))
         self.files_transferred += 1
@@ -176,3 +185,11 @@ class FileCopier(transfer.FileTransferer):
         self.already_copied.add((src, dst))
 
         return dst
+
+
+class CompressedFileCopier(FileCopier):
+    def _move(self, srcpath: pathlib.Path, dstpath: pathlib.Path):
+        compressor.move(srcpath, dstpath)
+
+    def _copy(self, srcpath: pathlib.Path, dstpath: pathlib.Path):
+        compressor.copy(srcpath, dstpath)