使用 `Cache-Control: no-cache` 时缓存如何验证响应？
How do caches validate the response when using `Cache-Control: no-cache`?
no-cache
The no-cache request directive asks caches to validate the response with the origin server before reuse.
Cache-Control: no-cache
no-cache allows clients to request the most up-to-date response even if the cache has a fresh response.
我的理解是，当使用no-cache时，缓存会根据系统时间来验证响应的时间，如果不相同，客户端将请求最新的响应，对吗？
如果不是，那么在使用 Cache-Control: no-cache 时缓存如何验证响应？
感谢, quoting from Hypertext Transfer Protocol (HTTP/1.1): Caching:
Validation
When a cache has one or more stored responses for a requested URI,
but cannot serve any of them (e.g., because they are not fresh, or
one cannot be selected; see Section 4.1), it can use the conditional
request mechanism [RFC7232] in the forwarded request to give the next
inbound server an opportunity to select a valid stored response to
use, updating the stored metadata in the process, or to replace the
stored response(s) with a new response. This process is known as
"validating" or "revalidating" the stored response.
no-cacheThe
no-cacherequest directive asks caches to validate the response with the origin server before reuse.Cache-Control: no-cache
no-cacheallows clients to request the most up-to-date response even if the cache has a fresh response.
我的理解是，当使用no-cache时，缓存会根据系统时间来验证响应的时间，如果不相同，客户端将请求最新的响应，对吗？
如果不是，那么在使用 Cache-Control: no-cache 时缓存如何验证响应？
感谢
Validation
When a cache has one or more stored responses for a requested URI, but cannot serve any of them (e.g., because they are not fresh, or one cannot be selected; see Section 4.1), it can use the conditional request mechanism [RFC7232] in the forwarded request to give the next inbound server an opportunity to select a valid stored response to use, updating the stored metadata in the process, or to replace the stored response(s) with a new response. This process is known as "validating" or "revalidating" the stored response.