commit 10fdb77c9485445f9e981e6def7279e161acb107
parent 9ad005ae420aab43253df8611406cb18bc0a8657
Author: lash <dev@holbrook.no>
Date: Fri, 11 Mar 2022 12:01:56 +0000
Add change method
Diffstat:
5 files changed, 112 insertions(+), 5 deletions(-)
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,5 +1,6 @@
- 0.1.1
* Add optional, pluggable verifier to protect state transition
+ * Add change method for atomic simultaneous set and unset
- 0.1.0
* Release version bump
- 0.0.19:
diff --git a/shep/persist.py b/shep/persist.py
@@ -14,8 +14,8 @@ class PersistedState(State):
:type logger: object
"""
- def __init__(self, factory, bits, logger=None):
- super(PersistedState, self).__init__(bits, logger=logger)
+ def __init__(self, factory, bits, logger=None, verifier=None):
+ super(PersistedState, self).__init__(bits, logger=logger, verifier=verifier)
self.__store_factory = factory
self.__stores = {}
@@ -78,6 +78,26 @@ class PersistedState(State):
return to_state
+ def change(self, key, bits_set, bits_unset):
+ """Persist a new state for a key or key/content.
+
+ See shep.state.State.unset
+ """
+ from_state = self.state(key)
+ k_from = self.name(from_state)
+
+ to_state = super(PersistedState, self).change(key, bits_set, bits_unset)
+
+ k_to = self.name(to_state)
+ self.__ensure_store(k_to)
+
+ contents = self.__stores[k_from].get(key)
+ self.__stores[k_to].add(key, contents)
+ self.__stores[k_from].remove(key)
+
+ return to_state
+
+
def move(self, key, to_state):
"""Persist a new state for a key or key/content.
diff --git a/shep/state.py b/shep/state.py
@@ -332,7 +332,7 @@ class State:
if self.verifier != None:
r = self.verifier(self, from_state, to_state)
if r != None:
- raise StateTransitionInvalid('{} -> {}: {}'.format(from_state, to_state, r))
+ raise StateTransitionInvalid(r)
self.__add_state_list(to_state, key)
current_state_list.pop(idx)
@@ -367,7 +367,7 @@ class State:
return self.__move(key, current_state, to_state)
-
+
def unset(self, key, not_state):
"""Unset a single bit, moving to a pure or alias state.
@@ -404,6 +404,28 @@ class State:
return self.__move(key, current_state, to_state)
+ def change(self, key, sets, unsets):
+ current_state = self.__keys_reverse.get(key)
+ if current_state == None:
+ raise StateItemNotFound(key)
+ to_state = current_state | sets
+ to_state &= ~unsets & self.__limit
+
+ if sets == 0:
+ to_state = current_state & (~unsets)
+ if to_state == current_state:
+ raise ValueError('invalid change by unsets for state {}: {}'.format(key, unsets))
+
+ if to_state == getattr(self, self.base_state_name):
+ raise ValueError('State {} for {} cannot be reverted to {}'.format(current_state, key, self.base_state_name))
+
+ new_state = self.__reverse.get(to_state)
+ if new_state == None:
+ raise StateInvalid('resulting to state is unknown: {}'.format(to_state))
+
+ return self.__move(key, current_state, to_state)
+
+
def state(self, key):
"""Return the current numeric state for the given content key.
diff --git a/tests/test_file.py b/tests/test_file.py
@@ -73,7 +73,41 @@ class TestStateReport(unittest.TestCase):
with self.assertRaises(FileNotFoundError):
os.stat(fp)
-
+
+ def test_change(self):
+ self.states.alias('inky', self.states.FOO | self.states.BAR)
+ self.states.put('abcd', state=self.states.FOO, contents='foo')
+ self.states.change('abcd', self.states.BAR, 0)
+
+ fp = os.path.join(self.d, 'INKY', 'abcd')
+ f = open(fp, 'r')
+ v = f.read()
+ f.close()
+
+ fp = os.path.join(self.d, 'FOO', 'abcd')
+ with self.assertRaises(FileNotFoundError):
+ os.stat(fp)
+
+ fp = os.path.join(self.d, 'BAR', 'abcd')
+ with self.assertRaises(FileNotFoundError):
+ os.stat(fp)
+
+ self.states.change('abcd', 0, self.states.BAR)
+
+ fp = os.path.join(self.d, 'FOO', 'abcd')
+ f = open(fp, 'r')
+ v = f.read()
+ f.close()
+
+ fp = os.path.join(self.d, 'INKY', 'abcd')
+ with self.assertRaises(FileNotFoundError):
+ os.stat(fp)
+
+ fp = os.path.join(self.d, 'BAR', 'abcd')
+ with self.assertRaises(FileNotFoundError):
+ os.stat(fp)
+
+
def test_set(self):
self.states.alias('xyzzy', self.states.FOO | self.states.BAR)
self.states.put('abcd', state=self.states.FOO, contents='foo')
diff --git a/tests/test_state.py b/tests/test_state.py
@@ -106,5 +106,35 @@ class TestState(unittest.TestCase):
self.assertEqual(states.from_name('foo'), states.FOO)
+
+ def test_change(self):
+ states = State(3)
+ states.add('foo')
+ states.add('bar')
+ states.add('baz')
+ states.alias('inky', states.FOO | states.BAR)
+ states.alias('pinky', states.FOO | states.BAZ)
+ states.put('abcd')
+ states.next('abcd')
+ states.set('abcd', states.BAR)
+ states.change('abcd', states.BAZ, states.BAR)
+ self.assertEqual(states.state('abcd'), states.PINKY)
+
+
+ def test_change_onezero(self):
+ states = State(3)
+ states.add('foo')
+ states.add('bar')
+ states.add('baz')
+ states.alias('inky', states.FOO | states.BAR)
+ states.alias('pinky', states.FOO | states.BAZ)
+ states.put('abcd')
+ states.next('abcd')
+ states.change('abcd', states.BAR, 0)
+ self.assertEqual(states.state('abcd'), states.INKY)
+ states.change('abcd', 0, states.BAR)
+ self.assertEqual(states.state('abcd'), states.FOO)
+
+
if __name__ == '__main__':
unittest.main()
