Defaults: add NodeSet's default folding axis (#401)

Add 'fold_axis' as a tunable of Defaults. If set, this is used by
NodeSet to disengage some nD folding. By default, nD folding is
tried on all axes.

A global Defaults is instantiated by the library, whose values can be
set in a config file. Below is an example of use to improve
compatiblity with Slurm:

/etc/clustershell/defaults.conf:

    [nodeset]
    fold_axis: -1

Once set, by default, the library will only fold node sets using the
last axis found.

Closes #401.

Change-Id: I41637c8e18567ae254dfb2118fe2e4420789f802

Author: thiell

lib/ClusterShell/Defaults.py

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2015-2017 Stephane Thiell <[email protected]>
+# Copyright (C) 2015-2019 Stephane Thiell <[email protected]>
 #
 # This file is part of ClusterShell.
 #
@@ -42,6 +42,7 @@
 #
 CFG_SECTION_TASK_DEFAULT = 'task.default'
 CFG_SECTION_TASK_INFO = 'task.info'
+CFG_SECTION_NODESET = 'nodeset'
 
 #
 # Functions
@@ -84,6 +85,20 @@ def config_paths(config_name):
                                         os.path.expanduser('~/.config')),
                          'clustershell', config_name)]
 
+def _converter_integer_tuple(value):
+    """ConfigParser converter for tuple of integers"""
+    # NOTE: compatible with ConfigParser 'converters' argument (Python 3.5+)
+    return tuple(int(x) for x in value.split(',') if x.strip())
+
+def _parser_get_integer_tuple(parser, section, option, **kwargs):
+    """
+    Compatible converter for parsing tuple of integers until we can use
+    converters from new ConfigParser (Python 3.5+).
+    """
+    return _converter_integer_tuple(
+        ConfigParser.get(parser, section, option, **kwargs))
+
+
 #
 # Classes
 #
@@ -93,7 +108,13 @@ class Defaults(object):
 
     The following attributes may be read at any time and also changed
     programmatically, for most of them **before** ClusterShell objects
-    are initialized (like Task):
+    (Task or NodeSet) are initialized.
+
+    NodeSet defaults:
+
+    * fold_axis (tuple of axis integers; default is empty tuple ``()``)
+
+    Task defaults:
 
     * stderr (boolean; default is ``False``)
     * stdin (boolean; default is ``True``)
@@ -181,12 +202,23 @@ class Defaults(object):
     #
     _TASK_INFO_PKEYS_BL = ['engine', 'print_debug']
 
+    #
+    # Default values for NodeSet
+    #
+    _NODESET = {"fold_axis" : ()}
+
+    #
+    # Datatype converters for NodeSet defaults
+    #
+    _NODESET_CONVERTERS = {"fold_axis" : _parser_get_integer_tuple}
+
     def __init__(self, filenames):
         """Initialize Defaults from config filenames"""
 
         self._task_default = self._TASK_DEFAULT.copy()
         self._task_info = self._TASK_INFO.copy()
         self._task_info_pkeys_bl = list(self._TASK_INFO_PKEYS_BL)
+        self._nodeset = self._NODESET.copy()
 
         config = ConfigParser()
         parsed = config.read(filenames)
@@ -212,22 +244,34 @@ def _parse_config(self, config):
             except (NoSectionError, NoOptionError):
                 pass
 
+        # NodeSet
+        for key, conv in self._NODESET_CONVERTERS.items():
+            try:
+                self._nodeset[key] = conv(config, CFG_SECTION_NODESET, key)
+            except (NoSectionError, NoOptionError):
+                pass
+
     def __getattr__(self, name):
         """Defaults attribute lookup"""
         if name in self._task_default:
             return self._task_default[name]
         elif name in self._task_info:
             return self._task_info[name]
+        elif name in self._nodeset:
+            return self._nodeset[name]
         raise AttributeError(name)
 
     def __setattr__(self, name, value):
         """Defaults attribute assignment"""
-        if name in ('_task_default', '_task_info', '_task_info_pkeys_bl'):
+        if name in ('_task_default', '_task_info', '_task_info_pkeys_bl',
+                    '_nodeset'):
             object.__setattr__(self, name, value)
         elif name in self._task_default:
             self._task_default[name] = value
         elif name in self._task_info:
             self._task_info[name] = value
+        elif name in self._nodeset:
+            self._nodeset[name] = value
         else:
             raise AttributeError(name)
 

lib/ClusterShell/NodeSet.py

@@ -60,7 +60,7 @@
 except NameError:
     basestring = str
 
-from ClusterShell.Defaults import config_paths
+from ClusterShell.Defaults import config_paths, DEFAULTS
 import ClusterShell.NodeUtils as NodeUtils
 
 # Import all RangeSet module public objects
@@ -137,6 +137,8 @@ def __init__(self, pattern=None, rangeset=None, copy_rangeset=True,
         self._length = 0
         self._patterns = {}
         self.fold_axis = fold_axis  #: iterable over nD 0-indexed axis
+        if self.fold_axis is None and DEFAULTS.fold_axis:
+            self.fold_axis = DEFAULTS.fold_axis  # non-empty tuple
         if pattern:
             self._add(pattern, rangeset, copy_rangeset)
         elif rangeset:

tests/DefaultsTest.py

@@ -23,6 +23,8 @@ def setUp(self):
 
     def test_000_initial(self):
         """test Defaults initial values"""
+        # nodeset
+        self.assertEqual(self.defaults.fold_axis, ())
         # task_default
         self.assertFalse(self.defaults.stderr)
         self.assertTrue(self.defaults.stdout_msgtree)
@@ -43,6 +45,9 @@ def test_000_initial(self):
 
     def test_001_setattr(self):
         """test Defaults setattr"""
+        # nodeset
+        self.defaults.fold_axis = (0, 2)
+        self.assertEqual(self.defaults.fold_axis, (0, 2))
         # task_default
         self.defaults.stderr = True
         self.assertTrue(self.defaults.stderr)
@@ -116,6 +121,8 @@ def setUp(self):
         self.defaults = None
 
     def _assert_default_values(self):
+        # nodeset
+        self.assertEqual(self.defaults.fold_axis, ())
         # task_default
         self.assertFalse(self.defaults.stderr)
         self.assertTrue(self.defaults.stdout_msgtree)
@@ -143,6 +150,9 @@ def test_000_empty(self):
     def test_001_defaults(self):
         """test Defaults config file (defaults)"""
         conf_test = make_temp_file(dedent("""
+            [nodeset]
+            fold_axis: 
+
             [task.default]
             stderr: false
             stdout_msgtree: true
@@ -165,6 +175,9 @@ def test_001_defaults(self):
     def test_002_changed(self):
         """test Defaults config file (changed)"""
         conf_test = make_temp_file(dedent("""
+            [nodeset]
+            fold_axis: -1
+
             [task.default]
             stderr: true
             stdout_msgtree: false
@@ -182,6 +195,9 @@ def test_002_changed(self):
             connect_timeout: 12.5
             command_timeout: 30.5""").encode('ascii'))
         self.defaults = Defaults(filenames=[conf_test.name])
+        # nodeset
+        self.assertEqual(self.defaults.fold_axis, (-1,))
+        # task_default
         self.assertTrue(self.defaults.stderr)
         self.assertFalse(self.defaults.stdout_msgtree)
         self.assertFalse(self.defaults.stderr_msgtree)

tests/NodeSetTest.py

@@ -570,6 +570,8 @@ def test_nd_fold_axis_errors(self):
         self.assertEqual(str(n1), "a[1,3]b2c0,a[1,3]b2c1,a2b[3-5]c1")
         n1.fold_axis = RangeSet("0-1") # ok
         self.assertEqual(str(n1), "a[1,3]b2c0,a[1,3]b2c1,a2b[3-5]c1")
+        n1.fold_axis = (0, 1) # ok
+        self.assertEqual(str(n1), "a[1,3]b2c0,a[1,3]b2c1,a2b[3-5]c1")
 
     def testSimpleNodeSetUpdates(self):
         """test NodeSet simple nodeset-based update()"""