[转]HTTP头的Expires与Cache-control
Posted by quentin 在 Friday, 29 October 20101.概念
Cache-control用于控制HTTP缓存(在HTTP/1.0中可能部分没实现,仅仅实现了Pragma: no-cache)
数据包中的格式:
Cache-Control: cache-directive
cache-directive可以为以下:
request时用到:
| "no-cache"
| "no-store"
| "max-age" "=" delta-seconds
| "max-stale" [ "=" delta-seconds ]
| "min-fresh" "=" delta-seconds
| "no-transform"
| "only-if-cached"
| "cache-extension"
response时用到: