| 摘要 |
Some embodiments provide systems and methods for validating cached content based on changes in the content instead of an expiration interval. One method involves caching content and a first checksum in response to a first request for that content. The caching produces a cached instance of the content representative of a form of the content at the time of caching. The first checksum identifies the cached instance. In response to receiving a second request for the content, the method submits a request for a second checksum representing a current instance of the content and a request for the current instance. Upon receiving the second checksum, the method serves the cached instance of the content when the first checksum matches the second checksum and serves the current instance of the content upon completion of the transfer of the current instance when the first checksum does not match the second checksum. |
