Delete cache if the bundle operation did not succeed. (#204)

* Delete cache if the bundle operation did not succeed.
For bundle v2, only use cache if the previous bundling succeeded.

Signed-off-by: Zachary Michaels <zacmicha@amazon.com>

colcon_bundle/verb/_archive_generators.py

@@ -121,6 +121,13 @@ def generate_archive_v2(path_context: PathContext,
 
     logger.info('Archiving complete')
     print('Archiving complete!')
+    _mark_cache_valid(path_context)
+
+
+def _mark_cache_valid(path_context):
+    cache_valid_file = path_context.cache_valid_path()
+    with open(cache_valid_file, 'a'):
+        os.utime(cache_valid_file)
 
 
 def recursive_tar_in_path(tar_path, path):

colcon_bundle/verb/_path_context.py

@@ -1,5 +1,6 @@
 import os
 from pathlib import Path
+import shutil
 
 from colcon_bundle.verb import check_and_mark_bundle_tool, \
     check_and_mark_bundle_version, \
@@ -47,6 +48,11 @@ def __init__(self,
         self._bundle_cache = self._bundle_base
         if cache_version == 2:
             self._bundle_cache = os.path.join(self._bundle_base, 'cache')
+            if os.path.exists(self.cache_valid_path()):
+                os.remove(self.cache_valid_path())
+            elif os.path.exists(self._bundle_cache):
+                print('Cache is not valid. Clearing cache...')
+                shutil.rmtree(self._bundle_cache)
             os.makedirs(self._bundle_cache, exist_ok=True)
         self._install_base = install_base
 
@@ -125,3 +131,7 @@ def bundle_v2_output_path(self):  # noqa: D400
     def sources_tar_gz_path(self):  # noqa: D400
         """:return: File path for sources files tarball"""
         return os.path.join(self._bundle_base, 'sources.tar.gz')
+
+    def cache_valid_path(self):  # noqa: D400
+        """:return: File path for cache valid file."""
+        return os.path.join(self._bundle_cache, '.valid')