Patent Abstract:
Disclosed is an apparatus for producing a resource descriptor for a particular resource having an associated URI, including a controller forming one or more candidate signatures for the particular resource wherein said controller identifies one of said candidate signatures having a predetermined level of correspondence to the particular resource as a signature for the particular resource; and a concatenator for merging the signature with the URI to produce the resource descriptor. A method, and computer program product having executable instructions for implementing the method, includes forming one or more candidate signatures for the particular resource wherein one of said candidate signatures having a predetermined level of correspondence to the particular resource is identified as a signature for the particular resource; and concatenating the signature with the URI to produce the resource descriptor.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     The present application is related to application Ser. No. ______ (2831P) entitled “Apparatus, Method and Computer Program Product for Resource Locator Using Queries” and filed on even date herewith. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to producing references to resources distributed over multiple locations, and more specifically to creating a generalized resource locator for accessing a particular resource and/or related resources potentially distributed across multiple locations across multiple computing systems on a network.  
       BACKGROUND OF THE INVENTION  
       [0003]     The use of a uniform resource locator (URL) by a web browser to locate and retrieve a particular document that is stored in a particular location on one of thousands of computer systems all connected to a network is well-known. The use of a URL in this instance is satisfactory for documents that are located where they are expected.  
         [0004]     However, if a document is moved, deleted or modified, the URL may become inappropriate for the document. The URL may be inappropriate because the document no longer resides at the location specified, or the document that resides at the location specified is not the one that was available when the URL was specified.  
         [0005]     In some instances, the document specified not only resides at the specified location, but in one or more other locations besides the specified location. Sometimes, it is advantageous to find these documents in the alternate locations.  
         [0006]     Accordingly, what is needed is a system and method for better management of documents distributed over multiple computers on a network.  
       SUMMARY OF THE INVENTION  
       [0007]     Disclosed is an apparatus for producing a resource descriptor for a particular resource having an associated URI, including a controller forming one or more candidate signatures for the particular resource wherein said controller identifies one of said candidate signatures having a predetermined level of correspondence to the particular resource as a signature for the particular resource; and a concatenator for merging the signature with the URI to produce the resource descriptor. A method, and computer program product having executable instructions for implementing the method, includes forming one or more candidate signatures for the particular resource wherein one of said candidate signatures having a predetermined level of correspondence to the particular resource is identified as a signature for the particular resource; and concatenating the signature with the URI to produce the resource descriptor.  
         [0008]     The apparatus, method and computer program product generate a signature for a particular resource that permits accessing of the resource, and copies of the resource, even when a URL for the resource is inappropriate (e.g., the resource has moved or has not been updated). 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a schematic block diagram for a preferred embodiment of a resource access apparatus;  
         [0010]      FIG. 2  is a schematic flow diagram for a preferred embodiment of a resource access process; and  
         [0011]      FIG. 3  is a schematic flow diagram for a preferred embodiment of a resource identifier creation process. 
     
    
     DETAILED DESCRIPTION  
       [0012]     The present invention relates to managing references to resources distributed over multiple locations. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein.  
         [0013]      FIG. 1  is a schematic block diagram for a preferred embodiment of a resource access apparatus  100  that uses a resource descriptor  105  having both a uniform resource identifier (URI)  110  and a signature  115 . Descriptor  105  is a reference to a specific resource  120   1  of a plurality of references  120   n  distributed over multiple locations, typically over multiple networked computers. URI  110  and signature  115  are written into a memory  125  coupled to a controller  130  that interacts with an access process  135 , in cooperation with a search engine  140 , for accessing one or more resources  120 . As used herein, resource refers to any directly addressable object, datum, file, or portion thereof. Memory includes typical memory formats (e.g., volatile or non-volatile semiconductor storage, magnetic storage, magneto-optic storage) as well as other storage formats such as, for example, a database, web page link in an hyper-text markup language (HTML) file.  
         [0014]     URI  110  may be any direct reference resource address, such as for example an address using a uniform resource locator (URL), a universal naming convention (UNC), or a directory-file structure (DFS) name. Signature  115  is a reference identity qualifier that has several potential uses. One use is to ensure that a resource located by a URI is in fact the desired document. A signature is generated from the located resource and compared to signature  115  supplied by resource descriptor  105 . Matching signatures (to within a tolerance) confirms that the located resource is the intended resource. For instance, if signature  115  is chosen to be a search query, the document located by the URI is consistent with signature  115 , if a search based on signature  115  returns the located document as the top (N) results in the result set.  
         [0015]     Additionally, signature  115  is used to locate the proper resource and closely related documents, and may be used even when URI finds the desired resource. In this use, signature  115  is actually a query that is reasonably guaranteed to return the desired resource as the top (or top N) entries in a related or qualified search result list of resources. When URI  110  locates a candidate resource, signature  115  qualifies the candidate resource when the located resource is returned in the search result list. Further, signature  115  may be used to find other copies of the desired resource as well as other resources similar to the desired resource. When URI  110  does not locate a candidate resource, signature  115  locates one or more candidate resources.  
         [0016]     Controller  130  is a microprocessor, microcontroller or the like that operates according to instructions specified by access process  135 , using the information stored in memory  125  to extract the resource descriptor  105  (or portions thereof) to locate and/or retrieve a desired resource and/or one or more qualified candidate resources.  
         [0017]     Access process  135  is a sequence of steps for confirming location, locating, accessing, retrieving, using, transferring, copying, deleting, modifying, etc., a particular resource  120   1 . Access process  135  may be implemented in a browser, file system, or other application or routine of a computing system.  
         [0018]     The use of search engines and of indexing engines on computing systems, intranets, extranets, networks, wide-area-networks, and other collections of computing systems is well-known. A usefulness of the preferred embodiment of the present invention is improved when a search engine is available and resources  120  are fully-indexed and reasonable efforts are made to maintain the indices. However, other signature systems may be used in other implementations, including systems for dynamic generation of signatures or signature-related information.  
         [0019]      FIG. 2  is a schematic flow diagram for a preferred embodiment of a resource access process  200 . Apparatus  100  shown in  FIG. 1  implements process  200  to access a resource using a resource descriptor. In typical operation, resource descriptor  105  is used in all places where reference to a particular resource is needed, for example, e-mails to colleagues, references to a hypertext document, and as document links in a document database.  
         [0020]     Process  200 , at step  205 , parses resource descriptor  105  into URI  110  and signature  115 . Next at step  210 , process  200  initiates operation of access process  135 . Process  200  first uses URI  110  to initiate an access of the desired resource  120   1 .  
         [0021]     At step  215 , process  200  determines whether a candidate resource is located from step  210 . When a candidate resource is found, process  200  may perform an optional test at step  220  to determine whether the candidate resource is qualified by signature  115 . An example of a qualification is whether signature  115  matches the candidate resource closely enough, or in the case of a query signature, whether the candidate resource is sufficiently close on a search score.  
         [0022]     When the candidate resource is qualified at step  220 , process  200  executes step  225  and returns the candidate resource. Step  225  may, in some implementations, not actually return the candidate resource, but return a URI for the candidate resource. In other implementations, the candidate resource may be operated on by some other process after being located at step  225 .  
         [0023]     If no candidate resource is found, or if a located candidate resource is not qualified, process  200  executes step  230  to use signature  115  to locate one or more qualified candidate resources. When signature  115  is a query, the query is applied to the applicable search engines.  
         [0024]     When the qualified candidate resource(s) are located at step  230 , process  200  executes step  235  to return the candidate resource(s). Step  235  may, in some implementations, not actually return the candidate resource(s), but return one or more URIs for the candidate resource(s). In other implementations, the candidate resource may be operated on by some other process after being located at step  235 . Providing search engine  140  with “fuzzy” searching capability permits location of similar resources to a specific intended URI.  
         [0025]      FIG. 3  is a schematic flow diagram for a preferred embodiment of a resource identifier creation process  300 . Process  300  begins at step  305  with an initial query (which in some cases is null or blank) or includes some specific initial value or set of values depending upon the implementation. Whatever the initial query at step  305 , process  300  next (step  310 ) selects a keyword to be used with the current value of the query. In the preferred embodiment, the existence of a full index of the resource set improves the value of the present invention. Step  310  selects a keyword from the index.  
         [0026]     Each keyword may be chosen in multiple ways. An “efficient” (e.g., a small) search query may be generated by first selecting keywords whose corresponding index entry is contained by the least number of resources. A search query that is a good signature of a particular resource is achieved by examining statistics of the resource. Keywords that are referenced a maximum number of times are selected first.  
         [0027]     Process  300  at step  315  merges or adds the keyword from step  310  to the current state of the query to produce a new query. The fitness of the new query as a signature is tested next at step  320 . Process  300  conducts a search using the query obtained from step  315  and examines a size of the result set. If the size is less than a predetermined size N, then the query from step  315  is satisfactory and the query/signature generation process concludes at step  325 .  
         [0028]     However, if at step  320  the search result size is greater than N, process  300  returns to step  310  to select a new keyword. Process  300  repeats step  310  through step  320  until the search result size is less than N.  
         [0029]     The following is an example of the preferred embodiment for use with a web-based magazine. A current issue is located at http://www.wbmagazine.com/issues/current/index.html. A subscriber of the magazine bookmarks the URI as indicated above and has easy access to the current issue of the magazine.  
         [0030]     The magazine provides users with access to articles and information contained in previous issues. Back issues of the magazine are kept at http://www.wbmagazine.com/issues/yyyy_mm_dd/index.html, with yyyy_mm_dd representing the publication date of any particular back issue. When a next issue is published, the content under http://www.wbmagazine.com/issues/current/index.html is moved to the appropriate location in the http://www.wbmagazine.com/issues/yyyy_mm_dd/index.html format.  
         [0031]     A reader is interested in a particular article regarding “java beans” in the current issue: http://www.wbmagazine.com/issues/current/features/javabeans.html. The reader bookmarks the location, without appreciating that when the next issue is published, the bookmark will be invalid. Failure of the bookmark leads the reader to attempt to search for the article, with the reader attempting to formulate an effective query to locate the java beans article. Unfortunately, it can be that there are a great many of articles regarding “java beans” as that may be a popular topic for the magazine. The search results may produce interesting articles, but the reader may need to expend considerable effort to find the desired article, if it is to be found at all.  
         [0032]     When the reader bookmarks a descriptor for the article instead of the URI, the problem is avoided. One possible presentation of the descriptor would be http://www.wbmagazine.com/issues/current/featuures/javabeans.html?query=“jb_signature” with the descriptor being a servlet request, though other implementations are possible. Using the descriptor to access the bookmarked issue, the web site will first attempt to use the URI to access the resource. If the article has moved, the servlet conducts a search on the site servers to locate the resource. Instead of an error page, the servlet returns a list of N candidate resources that the reader may choose from.  
         [0033]     When a candidate resource is found with the URI, the servlet qualifies the candidate resource to determine whether the resource is consistent with the signature. The servlet may again present a list of alternate candidate resources when the URI is not qualified. In some instances, even when the URI is qualified, the servlet may return a list of additional candidate resources similar to the resource at the URI.  
         [0034]     One of the preferred implementations of the present invention is as a routine in an operating system made up of programming steps or instructions resident in memory  125 ,  FIG. 1 , during computer operations. Until required by the computer system, the program instructions may be stored in another readable medium, e.g. in a disk drive, or in a removable memory, such as an optical disk for use in a CD ROM computer input or in a floppy disk for use in a floppy disk drive computer input. Further, the program instructions may be stored in the memory of another computer prior to use in the system of the present invention and transmitted over a LAN or a WAN, such as the Internet, when required by the user of the present invention. One skilled in the art should appreciate that the processes controlling the present invention are capable of being distributed in the form of computer readable media in a variety of forms.  
         [0035]     Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.

Technology Classification (CPC): 8