Document a few things, break out the subdirectory decorator even though it isn't used currently

apps/cli/executables/delivery/delivery/deliverer.py

@@ -11,15 +11,6 @@ from .destinations.sharedweb import SharedWebDestination
 from .destinations.fetchfile import FetchFileGenerator
 
 
-# class SubdirectoryDecorator(DestinationDecorator):
-#     def __init__(self, underlying: Destination, subdirectory: str):
-#         super().__init__(underlying)
-#         self.subdirectory = subdirectory
-#
-#     def add_file(self, relative_path: str, file: pathlib.Path):
-#         self.underlying.add_file(self.subdirectory + "/" + relative_path, file)
-
-
 class DestinationBuilder:
     """
     To facilitate building a stack of destination and its decorators.

apps/cli/executables/delivery/delivery/destinations/checksum.py

@@ -32,6 +32,11 @@ class ChecksumDecorator(DestinationDecorator):
 
     @staticmethod
     def hash_file(file: pathlib.Path):
+        """
+        Hash the supplied file
+        :param file: file to hash
+        :return: string in SHA1SUMS format (hexdigest)
+        """
         # You would expect performance to be worse than calling a C program here, but in my own testing I found
         # that the ensuing block is somewhat *faster* than calling "shasum" directly. I was able to hash a 1 GB
         # random file in 1.2 seconds with the following code, versus 1.8 seconds with shasum. This is across about 10

apps/cli/executables/delivery/delivery/destinations/subdirectory.py

+import pathlib
+
+from .interfaces import DestinationDecorator, Destination
+
+
+class SubdirectoryDecorator(DestinationDecorator):
+    """
+    A wrapper for making it easy to descend to subdirectories during delivery.
+    """
+
+    def __init__(self, underlying: Destination, subdirectory: str):
+        super().__init__(underlying)
+        self.subdirectory = subdirectory
+
+    def add_file(self, file: pathlib.Path, relative_path: str):
+        self.underlying.add_file(file, self.subdirectory + "/" + relative_path)

apps/cli/executables/delivery/delivery/destinations/tar.py

@@ -25,6 +25,14 @@ class TarArchiver(DestinationDecorator):
         self.archive.add(file, relative_path)
 
     def ensure_archive_created(self, relative_path: str):
+        """
+        This method guarantees that we have an open archive for writing.
+        If we do have an archive open, nothing happens; if we do not,
+        the archive is opened with a name derived from the supplied relative_path.
+
+        :param relative_path: path to the first file going into the archive
+        """
+
         # if we don't have the archive property yet, we must create the archive now
         if not self.archive:
             # the filename we generate will be the path to the first thing we're delivering with ".tar" appended