Encapsulate some general utility in utils

... but either way works.

Change-Id: I56b7689270e528a1d2099ff96030ce660e588c94
Related-Change-Id: Ic108f5c38f700ac4c7bcf8315bf4c55306951361

3 files changed, 49 insertions, 25 deletions

diff --git a/swift/common/db_replicator.py b/swift/common/db_replicator.py
index 0ef17094f..689db0e99 100644
--- a/swift/common/db_replicator.py
+++ b/swift/common/db_replicator.py
@@ -33,7 +33,7 @@ from swift.common.direct_client import quote
 from swift.common.utils import get_logger, whataremyips, storage_directory, \
     renamer, mkdirs, lock_parent_directory, config_true_value, \
     unlink_older_than, dump_recon_cache, rsync_module_interpolation, \
-    json, Timestamp, list_from_csv
+    json, Timestamp, parse_overrides
 from swift.common import ring
 from swift.common.ring.utils import is_local_device
 from swift.common.http import HTTP_NOT_FOUND, HTTP_INSUFFICIENT_STORAGE
@@ -47,20 +47,6 @@ from swift.common.swob import Response, HTTPNotFound, HTTPNoContent, \
 DEBUG_TIMINGS_THRESHOLD = 10
 
 
-def parse_overrides(daemon_kwargs):
-    devices = list_from_csv(daemon_kwargs.get('devices', ''))
-    if not devices:
-        devices = Everything()
-
-    partitions = [
-        int(part) for part in
-        list_from_csv(daemon_kwargs.get('partitions', ''))]
-    if not partitions:
-        partitions = Everything()
-
-    return devices, partitions
-
-
 def quarantine_db(object_file, server_type):
     """
     In the case that a corrupt file is found, move it to a quarantined area to
@@ -149,15 +135,6 @@ def roundrobin_datadirs(datadirs):
                 its.remove(it)
 
 
-class Everything(object):
-    """
-    A container that contains everything. If "e" is an instance of
-    Everything, then "x in e" is true for all x.
-    """
-    def __contains__(self, element):
-        return True
-
-
 class ReplConnection(BufferedHTTPConnection):
     """
     Helper to simplify REPLICATEing to a remote server.
@@ -679,7 +656,8 @@ class Replicator(Daemon):
 
     def run_once(self, *args, **kwargs):
         """Run a replication pass once."""
-        devices_to_replicate, partitions_to_replicate = parse_overrides(kwargs)
+        devices_to_replicate, partitions_to_replicate = parse_overrides(
+            **kwargs)
 
         self._zero_stats()
         dirs = []
diff --git a/swift/common/utils.py b/swift/common/utils.py
index 8209e7189..c0a837c4f 100644
--- a/swift/common/utils.py
+++ b/swift/common/utils.py
@@ -3416,6 +3416,15 @@ def get_valid_utf8_str(str_or_unicode):
     return valid_unicode_str.encode('utf-8')
 
 
+class Everything(object):
+    """
+    A container that contains everything. If "e" is an instance of
+    Everything, then "x in e" is true for all x.
+    """
+    def __contains__(self, element):
+        return True
+
+
 def list_from_csv(comma_separated_str):
     """
     Splits the str given and returns a properly stripped list of the comma
@@ -3426,6 +3435,27 @@ def list_from_csv(comma_separated_str):
     return []
 
 
+def parse_overrides(devices='', partitions='', **kwargs):
+    """
+    Given daemon kwargs parse out device and partition overrides or Everything.
+
+    :returns: a tuple of (devices, partitions) which an used like containers to
+              check if a given partition (integer) or device (string) is "in"
+              the collection on which we should act.
+    """
+    devices = list_from_csv(devices)
+    if not devices:
+        devices = Everything()
+
+    partitions = [
+        int(part) for part in
+        list_from_csv(partitions)]
+    if not partitions:
+        partitions = Everything()
+
+    return devices, partitions
+
+
 def csv_append(csv_string, item):
     """
     Appends an item to a comma-separated string.
diff --git a/test/unit/common/test_utils.py b/test/unit/common/test_utils.py
index 9fb543f51..c6359a69a 100644
--- a/test/unit/common/test_utils.py
+++ b/test/unit/common/test_utils.py
@@ -3518,6 +3518,22 @@ cluster_dfw1 = http://dfw1.host/v1/
             utils.get_hmac('GET', '/path', 1, 'abc'),
             'b17f6ff8da0e251737aa9e3ee69a881e3e092e2f')
 
+    def test_parse_overrides(self):
+        devices, partitions = utils.parse_overrides(devices='sdb1,sdb2')
+        self.assertIn('sdb1', devices)
+        self.assertIn('sdb2', devices)
+        self.assertNotIn('sdb3', devices)
+        self.assertIn(1, partitions)
+        self.assertIn('1', partitions)  # matches because of Everything
+        self.assertIn(None, partitions)  # matches because of Everything
+        devices, partitions = utils.parse_overrides(partitions='1,2,3')
+        self.assertIn('sdb1', devices)
+        self.assertIn('1', devices)  # matches because of Everything
+        self.assertIn(None, devices)  # matches because of Everything
+        self.assertIn(1, partitions)
+        self.assertNotIn('1', partitions)
+        self.assertNotIn(None, partitions)
+
     def test_get_policy_index(self):
         # Account has no information about a policy
         req = Request.blank(