配置继承机制

时间:2010-06-29 10:47:50

标签: python inheritance recursion

我有以下结构:

config
  |-- groups
    |-- rootgroup
    |-- group1 (includes rootgroup)
    |-- group2 (includes group1)
    |-- group3 (includes rootgroup)
  |-- users
    |-- Fred (includes group3 and group2)

Fred的继承树看起来像:

    _Fred_
   v      v
group2  group3
   v      v
group1    v
   v     /
rootgroup

我需要一个算法来打印从树左下角开始的线性配置读取顺序(例如,它将是rootgroup - group1 - group2 - group3; group1覆盖rootgroup,group2覆盖group1等...)并找到递归链接(例如,如果rootgroup包括组2),此外它必须找到递归循环(... - &gt; group2 - &gt; group1 - &gt; rootgroup - &gt; group2 - &gt; ...)。< / p>

优先使用的语言是python,但任何语言都可以。

感谢。

1 个答案:

答案 0 :(得分:0)

在阅读了有向无环图(DAG)后,我提出了以下解决方案:

def getNodeDepsTree(self, node, back_path=None):
    """Return whole dependency tree for given node"""
    # List of current node dependencies
    node_deps = []

    if not back_path:
        back_path = []

    # Push current node into return path list
    back_path.append(node)

    # Get current node dependencies list
    deps = getNodeDeps(node)

    for dep in deps:
        # If dependency persist in list of visited nodes - it's a recursion
        if dep in back_path:
            pos = back_path.index(dep)
            self.log.error("Recursive link detected. '" + node
                    + "', contains a recursive link to '" + dep
                    + "'. Removing dependency. Recursive loop is:\n\t"
                    + '\n\t'.join(back_path[pos:]))
            continue
        # Recursively call self for child nodes
        node_deps.extend(self.getNodeDepsTree(dep, back_path))

    # Finally add current node as dependency
    node_deps.append(node)

    # Remove current node from list of visited nodes and return
    back_path.pop()

    return node_deps