commonprefix() compares character-by-character (/..a../..b..),
sdcardfs : https://www.xda-developers.com/diving-into-sdcardfs-how-googles-fuse-replacement-will-reduce-io-overhead/
。业内人士推荐PDF资料作为进阶阅读
突出“两个联系” 发挥代表作用
在谈到小米的应对策略时，卢伟冰称小米产品覆盖了手机、平板、电视、汽车等品类，内存使用量和使用面是非常大的，小米也和全球五大内存生产商保持了非常好的合作关系，从供应角度来讲，小米目前没有面临任何的缺货现象。
both of these approaches use NFAs under the hood, which means O(m * n) matching. our approach is fundamentally different: we encode lookaround information directly in the automaton via derivatives, which gives us O(n) matching with a small constant. the trade-off is that we restrict lookarounds to a normalized form (?<=R1)R2(?=R3) where R1/R2/R3 themselves don’t contain lookarounds. the oracle-based approaches support more general nesting, but pay for it in the matching loop. one open question i have is how they handle memory for the oracle table - if you read a gigabyte of text, do you keep a gigabyte-sized table in memory for each lookaround in the pattern?