Multi-tiered caching mechanism for the storage and retrieval of content multiple versions

Abstract

Systems and methods for improved performance in the storing and retrieving of objects. In one embodiment, the invention comprises a multi-tiered caching system implemented in a network transformation proxy. The proxy performs transformations on Web content received from a Web server and stores the transformed content in the caching system. The lowest tier of caches stores the content as cache objects, while higher tiers store references to lower tiers (such as the tier which stores the objects) as their cache objects. Cache entries are looked up using a plurality of keys. Each of the keys is used to look up an entry in a different tier of the cache.

1 - 33 . (canceled)  
   
   
       34 . A multi-tiered caching system for storing Web content, comprising: 
 a plurality of caches organized in (n+1) tiers;    wherein each entry in an nth tier cache comprises a content-name key and a reference object;    wherein said content-name key identifies said Web content;    wherein said reference object references a (n+1)th tier cache storing said Web content;    wherein each entry in said (n+1)th tier cache comprises a version cache key and a content object;    wherein said content object stores a version of said Web content; and    wherein said version cache key specifies said version.    
   
   
       35 . The multi-tiered caching system of  claim 34 , wherein said (n+1)th cache stores multiple versions of said Web content.  
   
   
       36 . The multi-tiered caching system of  claim 34 , wherein said Web content comprises a Web page and wherein said (n+1)th cache stores multiple versions of said Web page.  
   
   
       37 . The multi-tiered caching system of  claim 36 , wherein said multiple versions are generated by a network transformation proxy as a result of performing one or more transformations on said Web page.  
   
   
       38 . The multi-tiered caching system of  claim 34 , wherein said version cache key encapsulates a parameterized transformation performed on said Web content and wherein said version of said Web content results from said parameterized transformation.  
   
   
       39 . The multi-tiered caching system of  claim 34 , wherein said content-name key comprises a name for said Web content.  
   
   
       40 . The multi-tiered caching system of  claim 39 , wherein said Web content comprises a Web page and wherein said content-name key comprises a uniform resource locator (URL) corresponding to said Web page.  
   
   
       41 . The multi-tiered caching system of  claim 34 , further comprises a plurality of (n+1) tier caches, wherein each of said plurality of (n+1)th tier caches comprises multiple entries corresponding to multiple versions of a content object identified by a single content-name key stored in said nth tier cache.  
   
   
       42 . The multi-tiered caching system of  claim 34 , wherein said (n+1)th tier cache is configured to store shared information that is common to all entries of said (n+1)th tier cache.  
   
   
       43 . The multi-tiered caching system of  claim 34 , wherein all entries in a cache selected from said plurality of caches are manipulatible via a combined operation.  
   
   
       44 . A method for retrieving content from a multi-tiered caching system, comprising: 
 identifying at least two keys associated with said content, wherein said at least two keys comprise a first key and a second key, where said first key identifies a name of said content, wherein said second key specifies a version of said content, and wherein said first key and said second key reside in different tiers of said multi-tiered caching system;    utilizing said first key to locate a cache in which multiple versions of said content are stored; and    utilizing said second key to obtain said version of said content.    
   
   
       45 . The method of  claim 44 , wherein the step of utilizing said first key to locate a cache further comprises looking up a first object associated with said first key, wherein said cache is a (n+1)th tier cache, wherein said first object identifying said (n+1)th tier cache, wherein said second key resides in said (n+1)th tier cache, and wherein said first key and said first object reside in an nth tier cache.  
   
   
       46 . The method of  claim 44 , wherein said content comprises a Web page and wherein said first key comprises a uniform resource locator (URL) of said Web page.  
   
   
       47 . The method of  claim 46 , wherein said cache stores multiple versions of said Web page identified by said URL.  
   
   
       48 . The method of  claim 47 , wherein the step of utilizing said first key to locate a cache comprises: 
 looking up a first entry in an nth tier cache that stores said URL, wherein said first entry contains said first key and a corresponding first object, and wherein said first object comprises a reference to said cache, wherein said cache is a (n+1)th tier cache; and    locating said (n+1)th tier cache using said reference.    
   
   
       49 . The method of  claim 48 , wherein the step of utilizing said second key to obtain said version of said content comprises: 
 looking up a second entry in said (n+1)th tier cache that stores multiple versions of said Web page identified by said URL, wherein said second entry contains said second key and a corresponding second object, and wherein said second object comprises said version of said Web page; and    retrieving said version of said Web page.    
   
   
       50 . A software product embodied in a computer-readable medium carrying computer-executable instructions implementing a method of caching and retrieving content via a multi-tiered cache system, wherein said computer-executable instructions comprise: 
 code for performing one or more transformations on said content, said one or more transformations generating multiple versions of said content;    code for generating a plurality of keys associated with said transformations and said content;    code for storing said plurality of keys and said multiple versions of said content in said multi-tiered cache system; and    code for utilizing at least two keys to retrieve a portion of said content from said multi-tiered cache system, wherein said at least two keys comprise a first key and a second key, where said first key identifies a name of said content, wherein said second key specifies a version of said content, and wherein said first key and said second key reside in different tiers of said multi-tiered cache system.    
   
   
       51 . The software product of  claim 50 , wherein said computer-executable instructions further comprise: 
 code for looking up a first object associated with said first key in a first entry of an nth tier cache;    code for accessing a (n+1)th tier cache identified by said first object; and    code for looking up a second object associated with said second key in a second entry of said a (n+1)th tier cache.    
   
   
       52 . The software product of  claim 51 , wherein said portion of said content comprises a Web page, wherein said second object comprises a version of said Web page, and wherein said first key comprises a uniform resource locator (URL) of said Web page.  
   
   
       53 . The software product of  claim 51 , wherein said computer-executable instructions further comprise: 
 code for manipulating all entries in said (n+1)th tier cache via a combined operation.