- From: Koen Holtman <koen@win.tue.nl>
- Date: Tue, 9 Jan 1996 19:54:36 +0100 (MET)
- To: mogul@pa.dec.com (Jeffrey Mogul)
- Cc: http-caching@pa.dec.com
Jeffrey Mogul: > >Koen writes: > The central point of your message, which seems to be that the 1.1 > draft does not define `cache' in a clear enough way, is better > addresed by Roy. > > For the record, I do think you have some point when you say that > browser authors can confuse caches with history buffers while > reading the 1.1 draft. But if we start calling history buffers > history caches, we will only add to that confusion. > >My opinions: > >(1) History buffers, whatever you want to call them, are different >enough from HTTP caches that we need to continue to make this explicit >in the specification. Agreed. I could even imagine that we would want to add a paragraph about the difference between caches and history mechanisms in Section 13 (Caching) of the 1.1 draft. >(2) Using the word "cache" to apply to both things seems to be >a recipe for confusion. On the principle that confusion is bad, >and that we ought to be able to agree on almost any term (even >a made-up word), I suggest that we use the term "history buffer" >unless someone else has a better suggestion. In particular, >let's avoid "history cache." > >(3) We need definitions of "cache" and "history buffer" to >put into the spec. I'm happy with Roy's definition of cache, >but in the absence of an equally concise definition of "history >buffer", I can see how some people could be confused. So I >invite people to try to write a definition of "history buffer" >for use in the spec, and (if necessary) minor tweaks to Roy's >definition of "cache" to address any possible confusion. OK, here is my try. cache A program's local store of HTTP response messages and the subsystem that controls its message storage, retrieval, and deletion. A cache stores cachable responses in order to reduce the response time and network bandwidth consumption on future, equivalent HTTP requests. Any client or server may include a cache, though a cache cannot be used by a server while it is acting as a tunnel. Though a cache located in a user agent may share memory with a history buffer, its message storage, retrieval, and deletion subsystem is usually different from the control subsystem of a history buffer. history buffer A user agent's local store containing entities retrieved earlier in a session, and the subsystem that controls its entity storage, retrieval, and deletion. User agent history mechanisms, such as "Back" buttons and history lists, preferably use, but are not limited to using, a history buffer to redisplay entities retrieved earlier. Though a history buffer may share memory with a cache, its entity storage, retrieval, and deletion subsystem is usually different from the control subsystem of a cache. >-Jeff Koen.
Received on Tuesday, 9 January 1996 19:17:38 UTC