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a/pyforge/flyway/graph.py |
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b/pyforge/flyway/graph.py |
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class MigrationGraph(object):
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class MigrationGraph(object):
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def __init__(self, migrations):
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def __init__(self, migrations):
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self._build_graph(migrations)
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self._build_graph(migrations)
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def reset(self):
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for n in self._nodes: n.reset()
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def _build_graph(self, migrations):
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def _build_graph(self, migrations):
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'''Build a graph where the nodes are possible migration states and the
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'''Build a graph where the nodes are possible migration states and the
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edges are transitions between states allowed by migrations.
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edges are transitions between states allowed by migrations.
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'''
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'''
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class Node(object):
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class Node(object):
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def __init__(self, state):
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def __init__(self, state):
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self.state = state
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self.state = state
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self.succs = [] # list of (state, migrationstep)
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self.reset()
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def reset(self):
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self.visited = False
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self.visited = False
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self.pred = None # (state, migrationstep)
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self.distance = 1e9 # effectively inf
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self.distance = 1e9 # effectively inf
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self.pred = None # (state, migrationstep)
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self.succs = [] # list of (state, migrationstep)
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def visit(self, nodes):
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def visit(self, nodes):
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'''The 'visit' step of Dijkstra's shortest-path algorithm'''
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'''The 'visit' step of Dijkstra's shortest-path algorithm'''
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self.visited = True
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self.visited = True
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new_dist = self.distance + 1
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new_dist = self.distance + 1
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