const time = (target - pos) / sp;
不止手机，笔记本电脑也曾经尝试过硬件集成的防窥功能，惠普当年的 Sure View 技术方案就是其中一例：
，推荐阅读safew官方版本下载获取更多信息
15:22, 27 февраля 2026Силовые структуры
软件是否正面临颠覆性变革像Workday希望依靠创始人回归进入全新的第二阶段——AI时代。但这一阶段又不同于云计算时代，后者在落地时是基本确定的前景，而AI虽然技术前景可观，但怎么落地，客户怎么接受，从底层基础设施到上层的应用和安全方面，仍有诸多模糊不清的探索方向。
Git packfiles use delta compression, storing only the diff when a 10MB file changes by one line, while the objects table stores each version in full. A file modified 100 times takes about 1GB in Postgres versus maybe 50MB in a packfile. Postgres does TOAST and compress large values, but that’s compressing individual objects in isolation, not delta-compressing across versions the way packfiles do, so the storage overhead is real. A delta-compression layer that periodically repacks objects within Postgres, or offloads large blobs to S3 the way LFS does, is a natural next step. For most repositories it still won’t matter since the median repo is small and disk is cheap, and GitHub’s Spokes system made a similar trade-off years ago, storing three full uncompressed copies of every repository across data centres because redundancy and operational simplicity beat storage efficiency even at hundreds of exabytes.