1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
#
class Category:
def __init__(self, name, **args):
self.args = args
self.name = name
def equiv(self, other):
if self.name != other.name: return False
for key, value in self.args.iteritems():
if not other.args.has_key(key): return False
if value == None: continue
if other.args[key] == None: continue
if not other.args[key] == value: return False
return True
def intersect(self, other):
if self.name != other.name: return None
args = {}
for key in list(set(self.args.keys() + other.args.keys())):
if not self.args.has_key(key):
args[key] = other.args[key]
elif not other.args.has_key(key):
args[key] = self.args[key]
elif self.args[key] == None:
args[key] = other.args[key]
elif other.args[key] == None:
args[key] = self.args[key]
elif self.args[key] != other.args[key]:
return None
else: # self.args[key] == other.args[key]
args[key] = self.args[key]
return Category(self.name, **args)
def __str__(self):
string = self.name + "("
had = False
for key, val in self.args.iteritems():
if had:
string += ", "
had = True
if val == None:
string += "%%%s" % key
else:
string += "%s: %s" % (key, val)
return string + ")"
def __repr__(self):
return self.__str__()
def __hash__(self):
return hash((self.argstup(), self.name))
def __eq__(self, other):
return self.name == other.name and self.argstup() == other.argstup()
def argstup(self):
retval = []
keys = self.args.keys()
keys.sort()
for key in keys:
retval.append((key, self.args[key]))
return tuple(retval)
def filter(self, other):
if not other.name == self.name:
raise TypeError, "States must be the same class"
args = {}
for key, value in other.args.iteritems():
if value != None or not self.args.has_key(key):
args[key] = value
else:
args[key] = self.args[key]
return Category(self.name, **args)
def fill(self, info):
args = {}
for key, value in self.args.iteritems():
if value != None or not info.has_key(key):
args[key] = value
else:
args[key] = info[key]
return Category(self.name, **args)
def is_finite(self):
return not None in self.args.values()
class StateMachine:
def __init__(self):
self.holds = {}
self.deps = []
def assert_state(self, cat):
found = None
for dependency in self.get_applicable_deps(cat):
res = self.get_satisfied_states(cat, dependency)
if len(res) == 0:
return False
if found == None:
found = res
else:
found = self.intersect_list(found, res)
if found == None:
self.add_hold(cat)
return True
if len(found) == 0:
return False
for x in found:
self.add_hold(x)
return True
def intersect_list(self, cats1, cats2):
retval = set()
found = set()
for x in cats1:
for y in cats2:
if x == y: continue
inter = x.intersect(y)
if inter != None:
retval.add(inter)
found.add(x)
found.add(y)
if len(found) == 0:
return cats1 & cats2
return (retval | ((cats1 & cats2) - found))
def add_hold(self, cat):
if self.holds.has_key(cat):
self.holds[cat] = self.holds[cat] + 1
else:
self.holds[cat] = 1
def get_satisfied_states(self, dependents, dependencies):
retval = []
for key, val in self.holds.iteritems():
if dependencies.equiv(key) and val > 0:
retval.append(dependents.fill(key.args))
return set(retval)
def get_applicable_deps(self, cat):
retval = []
for (x, y) in self.deps:
if x.equiv(cat):
retval.append(y.fill(cat.filter(x).args))
return retval
if __name__ == "__main__":
sm = StateMachine()
sm.deps.append((Category("mounted", type="nfs"), Category("network_up")))
sm.deps.append((Category("mounted", uuid=None, devname=None, label=None), Category("found_disk", uuid=None, devname=None, label=None)))
sm.deps.append((Category("mounted", uuid=None, devname=None, label=None), Category("vol_conf", uuid=None, devname=None, label=None)))
sm.assert_state(Category("vol_conf", uuid=None, devname=None, label="myroot", type="ext3", mountpoint="/"))
sm.assert_state(Category("found_disk", uuid="d3adb3ef", devname="/dev/sda", label="myroot"))
sm.assert_state(Category("mounted", uuid=None, type="ext3", devname=None, label=None, mountpoint=None))
print sm.holds
|
