Implement `minutely' option (issue #5)

README.rst

@@ -120,6 +120,11 @@ Please use the ``--dry-run`` option to test the effect of the specified rotation
    :widths: 30, 70
 
 
+   "``-M``, ``--minutely=COUNT``","In a literal sense this option sets the number of ""backups per minute"" to
+   preserve during rotation. For most use cases that doesn't make a lot of
+   sense :-) but you can combine the ``--minutely`` and ``--relaxed`` options to
+   preserve more than one backup per hour.  Refer to the usage of the ``-H``,
+   ``--hourly`` option for details about ``COUNT``."
    "``-H``, ``--hourly=COUNT``","Set the number of hourly backups to preserve during rotation:
 
    - If ``COUNT`` is a number it gives the number of hourly backups to preserve,
@@ -130,13 +135,13 @@ Please use the ``--dry-run`` option to test the effect of the specified rotation
      preserved.
    - By default no hourly backups are preserved."
    "``-d``, ``--daily=COUNT``","Set the number of daily backups to preserve during rotation. Refer to the
-   usage of the ``-H``, ``--hourly`` option for details."
+   usage of the ``-H``, ``--hourly`` option for details about ``COUNT``."
    "``-w``, ``--weekly=COUNT``","Set the number of weekly backups to preserve during rotation. Refer to the
-   usage of the ``-H``, ``--hourly`` option for details."
+   usage of the ``-H``, ``--hourly`` option for details about ``COUNT``."
    "``-m``, ``--monthly=COUNT``","Set the number of monthly backups to preserve during rotation. Refer to the
-   usage of the ``-H``, ``--hourly`` option for details."
+   usage of the ``-H``, ``--hourly`` option for details about ``COUNT``."
    "``-y``, ``--yearly=COUNT``","Set the number of yearly backups to preserve during rotation. Refer to the
-   usage of the ``-H``, ``--hourly`` option for details."
+   usage of the ``-H``, ``--hourly`` option for details about ``COUNT``."
    "``-I``, ``--include=PATTERN``","Only process backups that match the shell pattern given by ``PATTERN``. This
    argument can be repeated. Make sure to quote ``PATTERN`` so the shell doesn't
    expand the pattern before it's received by rotate-backups."

rotate_backups/__init__.py

@@ -41,7 +41,7 @@
 from verboselogs import VerboseLogger
 
 # Semi-standard module versioning.
-__version__ = '4.1'
+__version__ = '4.2'
 
 # Initialize a logger for this module.
 logger = VerboseLogger(__name__)
@@ -52,11 +52,14 @@
 LOCAL_CONFIG_FILE = '~/.rotate-backups.ini'
 """The pathname of the user specific configuration file (a string)."""
 
-ORDERED_FREQUENCIES = (('hourly', relativedelta(hours=1)),
-                       ('daily', relativedelta(days=1)),
-                       ('weekly', relativedelta(weeks=1)),
-                       ('monthly', relativedelta(months=1)),
-                       ('yearly', relativedelta(years=1)))
+ORDERED_FREQUENCIES = (
+    ('minutely', relativedelta(minutes=1)),
+    ('hourly', relativedelta(hours=1)),
+    ('daily', relativedelta(days=1)),
+    ('weekly', relativedelta(weeks=1)),
+    ('monthly', relativedelta(months=1)),
+    ('yearly', relativedelta(years=1)),
+)
 """
 A list of tuples with two values each:
 
@@ -314,8 +317,8 @@ def rotation_scheme(self):
         The rotation scheme to apply to backups (a dictionary).
 
         Each key in this dictionary defines a rotation frequency (one of the
-        strings 'hourly', 'daily', 'weekly', 'monthly' and 'yearly') and each
-        value defines a retention count:
+        strings 'minutely', 'hourly', 'daily', 'weekly', 'monthly' and
+        'yearly') and each value defines a retention count:
 
         - An integer value represents the number of backups to preserve in the
           given rotation frequency, starting from the most recent backup and
@@ -527,6 +530,7 @@ def group_backups(self, backups):
         """
         backups_by_frequency = dict((frequency, collections.defaultdict(list)) for frequency in SUPPORTED_FREQUENCIES)
         for b in backups:
+            backups_by_frequency['minutely'][(b.year, b.month, b.day, b.hour, b.minute)].append(b)
             backups_by_frequency['hourly'][(b.year, b.month, b.day, b.hour)].append(b)
             backups_by_frequency['daily'][(b.year, b.month, b.day)].append(b)
             backups_by_frequency['weekly'][(b.year, b.week)].append(b)

rotate_backups/cli.py

@@ -29,6 +29,14 @@
 
 Supported options:
 
+  -M, --minutely=COUNT
+
+    In a literal sense this option sets the number of "backups per minute" to
+    preserve during rotation. For most use cases that doesn't make a lot of
+    sense :-) but you can combine the --minutely and --relaxed options to
+    preserve more than one backup per hour.  Refer to the usage of the -H,
+    --hourly option for details about COUNT.
+
   -H, --hourly=COUNT
 
     Set the number of hourly backups to preserve during rotation:
@@ -44,22 +52,22 @@
   -d, --daily=COUNT
 
     Set the number of daily backups to preserve during rotation. Refer to the
-    usage of the -H, --hourly option for details.
+    usage of the -H, --hourly option for details about COUNT.
 
   -w, --weekly=COUNT
 
     Set the number of weekly backups to preserve during rotation. Refer to the
-    usage of the -H, --hourly option for details.
+    usage of the -H, --hourly option for details about COUNT.
 
   -m, --monthly=COUNT
 
     Set the number of monthly backups to preserve during rotation. Refer to the
-    usage of the -H, --hourly option for details.
+    usage of the -H, --hourly option for details about COUNT.
 
   -y, --yearly=COUNT
 
     Set the number of yearly backups to preserve during rotation. Refer to the
-    usage of the -H, --hourly option for details.
+    usage of the -H, --hourly option for details about COUNT.
 
   -I, --include=PATTERN
 
@@ -186,13 +194,16 @@ def main():
     selected_locations = []
     # Parse the command line arguments.
     try:
-        options, arguments = getopt.getopt(sys.argv[1:], 'H:d:w:m:y:I:x:jpri:c:r:unvqh', [
-            'hourly=', 'daily=', 'weekly=', 'monthly=', 'yearly=', 'include=',
-            'exclude=', 'parallel', 'prefer-recent', 'relaxed', 'ionice=',
-            'config=', 'use-sudo', 'dry-run', 'verbose', 'quiet', 'help',
+        options, arguments = getopt.getopt(sys.argv[1:], 'M:H:d:w:m:y:I:x:jpri:c:r:unvqh', [
+            'minutely=', 'hourly=', 'daily=', 'weekly=', 'monthly=', 'yearly=',
+            'include=', 'exclude=', 'parallel', 'prefer-recent', 'relaxed',
+            'ionice=', 'config=', 'use-sudo', 'dry-run', 'verbose', 'quiet',
+            'help',
         ])
         for option, value in options:
-            if option in ('-H', '--hourly'):
+            if option in ('-M', '--minutely'):
+                rotation_scheme['minutely'] = coerce_retention_period(value)
+            elif option in ('-H', '--hourly'):
                 rotation_scheme['hourly'] = coerce_retention_period(value)
             elif option in ('-d', '--daily'):
                 rotation_scheme['daily'] = coerce_retention_period(value)

rotate_backups/tests.py

@@ -360,6 +360,17 @@ def test_prefer_new(self):
             assert not os.path.exists(os.path.join(root, 'backup-2016-01-10_21-30-00'))
             assert os.path.exists(os.path.join(root, 'backup-2016-01-10_21-45-00'))
 
+    def test_minutely_rotation(self):
+        """Test rotation with multiple backups per hour."""
+        with TemporaryDirectory(prefix='rotate-backups-', suffix='-test-suite') as root:
+            os.mkdir(os.path.join(root, 'backup-2016-01-10_21-15-00'))
+            os.mkdir(os.path.join(root, 'backup-2016-01-10_21-30-00'))
+            os.mkdir(os.path.join(root, 'backup-2016-01-10_21-45-00'))
+            run_cli('--prefer-recent', '--relaxed', '--minutely=2', root)
+            assert not os.path.exists(os.path.join(root, 'backup-2016-01-10_21-15-00'))
+            assert os.path.exists(os.path.join(root, 'backup-2016-01-10_21-30-00'))
+            assert os.path.exists(os.path.join(root, 'backup-2016-01-10_21-45-00'))
+
     def create_sample_backup_set(self, root):
         """Create a sample backup set to be rotated."""
         for name in SAMPLE_BACKUP_SET: