[wsrp-wsia] [I#97] Caching Mechanism

Topic: 
interface

Class:  Technical

Title: 
Caching Mechanism

Document Section: Interfaces/6.1

Description:

I am 
submitting the following proposition to the committee as a proposition for 
dealing with caching of the markup. This proposition deals with "Expires"-like 
methods of caching, along with "If-Modified-Since/ETags" type of caching. I 
believe it is simple enough to be included in the v1.0 spec.

 

Caching Proposal

[The 
proposal is described as edits to the spec]

 

6.1 Operations [getMarkup]

 

[instead of 
expires in markupResponse, add the following]

cacheControl: A data structure, defined in Section 11, 
which includes information which CAN be used by the Consumer to cache the markup. This structure 
includes:

    validUntil: The time at which the markup is valid. Until that time the Consumer CAN use 
its cache entry instead of calling getMarkup. 
After this time passes, the Consumer MAY continue to use this cache 
entry, but only after validating it with a getMarkup operation, using the validationTag below, if given.

    validationTag: 
The Consumer MUST store this tag along with the markup while the markup is valid. This 
enables the Producer to use this tag to invalidate the cache entry by sending an 
invalidationTagPrefix in the performInteraction operation. 
After the markup expires, the 
Consumer CAN send the validationTag in the markupResponse to indicate that it still has the markup but would like to 
validate it. The Producer returns a fault response [TBD] to indicate that 
the markup is still valid, otherwise if it returns markup , the Consumer 
MUST invalidate the old markup.

 

[add to 
markupContext the following 
field]

   validationTag: This field CAN be sent to indicate that the Consumer has cached 
markup (which was tagged by the Producer with this value) and wishes to check 
whether it is still valid. See validationTag in markupResponse for more 
information. 

 

6.1 
Operations [performInteraction]

[add the 
following field to interactionResponse]
    invalidationTagPrefix: If the Producer returned this 
value, the Consumer MUST expire all markup-s who's 
validationTag begins with this value. The Consumer MUST not call getMarkup with 
these invalidationTag-s to validate these 
expired markup-s.

 

[add these 
fields to the relevant places in section 11]

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Discussion: