https://zhuanlan.zhihu.com/p/23645648
【学习】http://blog.topspeedsnail.com/?nsukey=z7XvFXAVXMyrJI1Izt1RKTxge0YvtcvuZmRFxElC%2BmP%2FX41UZ88tiGIijL%2F%2BrQ03E%2BctgbSA9rg4Lh8RHjXx3V6%2FFqujcZbYWGwr6m4zn0GCyWgbJrYMyr6wIKJCIh4R23BkQmE9ruDWR6HxT5N%2F9c0yEMUvg%2BYWx7sWzd0qeeMLva7sKwLGEn%2BPLGzHsASR