ESubtreeMap类分析

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ESubtreeMap类说明:
 class ESubtreeMap: public LogEvent {
  EMetaBlob metablob;
  map<dirfrag_t, vector<dirfrag_t>> subtrees;
  set<dirfrag_t> ambiguous_subtrees;
  uint64_t expire_pos;
  uint64_t event_seq;
 }:
 
ESubtreeMap类方法：
ESubtreeMap::replay(mds)
|__若expire_pos有效且大于当前MDLog中journaler的expire pos 
  |__设置MDLog的journaler expire pos值，即：mds->mdlog->journaler->set_expire_pos(expire_pos)
|__若MDCache是subtrees
  |__遍历subtrees
    |__从MDCache中得到subtree_root对应的CDir
    |__检查subtree root对应的CDir是否是subtree
    |__遍历subtree_root下面的所有dirfrags
      |__在MDCache中执行get_force_dirfrag操作，即：mds->mdcache->get_force_dirfrag()
    |__在MDCache中得到subtree_root的subtree bound，即：mds->mdcache->get_subtree_bound()
    |__遍历subtree_root下面的所有dirfrags
      |__从subtree bound数组中删除dirfrags
    |__若ambiguous_subtrees数组中包含subtree_root
      |__检查MDCache中是否在ambiguous中包含subtree_root，即：mds->mdcache->have_ambiguous_import()
    |__若ambiguous_subtrees数组中不包含subtree_root
      |__检查MDCache中是否在ambiguous中包含subtree_root，即：mds->mdcache->have_ambiguous_import()
  |__从MDCache中得到subtrees，即：mds->mdcache->list_subtrees()
  |__遍历MDCache中的subtrees
    |__检查MDCache着那个的subtrees是否在ESubtreeMap类的subtrees集合中
|__执行EMetaBlob::replay操作
|__遍历subtrees数组
  |__从MDCache中得到subtree_root对应的CDir
  |__检查subtree_root是否在ambiguous_subtrees数组中
    |__在MDCache中添加ambiguous信息，即：mds->mdcache->add_ambiguous_import()
    |__在MDCache中调整subtree auth，即：mds->mdcache->adjust_bounded_subtree_auth()
  |__subtree_root不再ambiguous_subtrees数组中
    |__在MDCache中调整subtree auth，即：mds->mdcache->adjust_bounded_subtree_auth()
|__在MDCache中执行recalc auth bits，即：mds->mdcache->recalc_auth_bits()

转载于:https://my.oschina.net/linuxhunter/blog/716075