Abstract:
A method of converting between a uniform resource locator and a dynamically compressed uniform resource locator involving parsing the components of the uniform resource locator, generating a token that uniquely identifies the combination of a path and a static query string parameter of the uniform resource locator, caching the token, the path, and the static query string parameter, and appending a dynamic query string parameter of the uniform resource locator to the token to form a compressed uniform resource locator.

Description:
BACKGROUND 
   Generally, a uniform resource locator (URL) is an address for a resource on a network. For example, URLs are utilized by web browsers to locate resource on the Internet. A URL specifies the protocol to be used in accessing a particular resource, and the IP address or domain name where the resource is located. 
   In an exemplary implementation, a web service (e.g., mail application) is provided on a first network device. The means of navigation amongst various pieces of the web service (e.g., received massages, sent messages and the like) is provided by URLs. Accordingly, the first network device (e.g., server device) transmits content (e.g., response) across a communication channel to a second network device (e.g., client device) according to a specified URL. The first network device also receives content (e.g., request) across the communication channel from the second network device. In one implementation the content is encoded in an HTTP command that includes one or more URLs (e.g., links). 
   A URL is composed of a pathname and one or more query string parameters. In the case of an application, the application may be implemented as a hierarchy of Java Server Pages (JSP), servelets, applets, common gateway interfaces, HyperText Markup Language (HTML) pages or the like. The JSPs, servelets, applets, common gateway interfaces, HTML pages or the like of the application can be organizes as a hierarchy. The hierarchy can have arbitrary depth and is organized to reflect device classes of ever increasing specificity. The deeper one goes in the hierarchy the more specific the JSP, servelet, applet, common gateway interface, HTML page or the like is to a particular device, class of devices, type of application or the like. Accordingly, the URLs of a given response can grow in size and number. Depending upon how specific the link becomes, the path and/or query string parameters can become very long. Thus, for any given response from a web application, the URLs can become a significant fraction of the total response. 
   SUMMARY 
   In general, in one aspect, the invention relates to a method of converting between a uniform resource locator and a dynamically compressed uniform resource locator comprising parsing the components of the uniform resource locator, generating a token that uniquely identifies the combination of a path and a static query string parameter of the uniform resource locator, caching the token, the path, and the static query string parameter, and appending a dynamic query string parameter of the uniform resource locator to the token to form a compressed uniform resource locator. 
   In general, in one aspect, the invention relates to a computer-readable medium containing instructions which when executed cause a network device to implement a method comprising receiving content containing a uniform resource locator, parsing the components of the uniform resource locator, determining whether a compression object corresponding to the uniform resource locator has previously been cached, generating a token that uniquely identifies the combination of a path and a static query string parameter of the uniform resource locator if the compression object has not previously been cached, caching the compression object if the compression object has not previously been cached, retrieving the token from the compression object if the compression object has previously been cached, appending a dynamic query string parameter of the uniform resource locator to the token to form a compressed uniform resource locator, encoding the compressed uniform resource locator in a response, and sending the response. 
   In general, in one aspect, the invention relates to a compressed uniform resource locator comprising a token, wherein a path and a static query string parameter of a uniform resource locator is uniquely identified, and a dynamic query string parameter, of the uniform resource locator, appended to the token. 
   In general, in one aspect, the invention relates to A network system having a plurality of nodes, comprising a token, wherein a path and a static query string parameter of a uniform resource locator is uniquely identified, and a dynamic query string parameter, of the uniform resource locator, appended to the token, wherein the token is located on any one of the plurality of nodes, and wherein the dynamic query string parameter is located on any one of the plurality of nodes. 
   Other aspects of the invention will be apparent from the following description and the appended claims. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  shows a data diagram of a uniform resource locator and a corresponding dynamic compression thereof, in accordance with one embodiment of the invention. 
       FIG. 2  shows a method of dynamically compressing a uniform resource locator, in accordance with one embodiment of the invention. 
       FIG. 3  shows a data diagram of a dynamic uniform resource locator compression table, in accordance with one embodiment of the invention. 
       FIG. 4  shows a method of reconstructing a uniform resource locator from a dynamically compressed uniform resource locator, in accordance with one embodiment of the invention. 
       FIG. 5  shows a block diagram of a network for implementing embodiments of the invention. 
       FIGS. 6A and 6B  show a method of dynamically compressing a uniform resource locator and reconstructing the uniform resource locator there from, in accordance with one embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   Specific embodiments of the invention will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency. 
   In the following detailed description of one or more embodiments of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid obscuring the invention. 
     FIG. 1  shows a data diagram of a uniform resource locator (URL)  140  and a corresponding dynamic compression  160  thereof, in accordance with one embodiment of the invention. The URL  140  is composed of a path  110  and one or more query string parameters  120 ,  130 . The URL  140  can have an arbitrary number of query string parameters  120 ,  130 , wherein each parameter can be of arbitrary length. 
   There are two types of query string parameters, static query string parameters  120  and dynamic query string parameters  130 . Static query string parameters  120  are those query string parameters of a given URL  140  that are not modified by a requesting device. Dynamic query string parameters  130  are those query string parameters of a given URL  140  that are modified by a requesting device. For example, a requesting device may specify a value of a named dynamic query string parameter. 
   The URL  140  is compressed by reducing the path  110  and static query string parameters  120  into a token  150 . The dynamic query string parameters  130  are appended to the token  150  to form the compressed URL  160 . The token  150  is a unique identifier associated with the combination of the particular path  110  and static query string parameters  120 . 
   Similarly, The URL  140  can be reconstructed from the compressed URL  160  by determining the path  110  and the static query string parameters  120  from the token  150  in the compressed URL. The dynamic query string parameters  130  are appended to the determined path  110  and static query string parameters  120  to reconstruct the URL  140 . 
     FIG. 2  shows a method of dynamically compressing a uniform resource locator (URL), in accordance with one embodiment of the invention. As depicted in  FIG. 2 , the path, static query string parameters and dynamic query string parameters of a particular URL are identified at  210 . The path of the URL denotes a request for a particular resource (e.g., JSP, servelet, applet, common gateway interface, HTML page or the like). The static type parameters of a URL, from a requesting network device (e.g., client device), will have the same name and value as was originally provided by a responding network device (e.g., web server). The dynamic type parameters of a URL, from the requesting device, may have a value specified that was not contained in the content originally sent by the responding network device. Because the path and static parameters in a response and a subsequent request thereto are the same, the path and static parameters need not be sent. 
   At  220 , a token that uniquely identifies the combination of the particular path and static query string parameters is generated. At  230 , the path, static query string parameters and token are cached as a compression object. In one implementation, the token, path and static query string parameters are cached locally in a dynamic URL compression table (e.g., in the web server). At  240 , the dynamic query string parameters are appended to the token to generate a compressed URL. 
   Additionally, the invention may be implemented on a distributed system having a plurality of nodes, where each portion of the invention (e.g., the token, the dynamic query string parameter, etc.) may be located on a different node within the distributed system. In one embodiment of the invention, the node corresponds to a computer system. Alternatively, the node may correspond to a processor with associated physical memory. 
     FIG. 3  shows a data diagram of a dynamic uniform resource locator (URL) compression table  300 , in accordance with one embodiment of the invention. The dynamic URL compression table  300  includes one or more compression objects (e.g., records)  310 . Each compression object  310  includes a token  320 , a path  330  and one or more static query string parameters  340 . A particular token  320  uniquely identifies a particular combination of path  330  and one or more query string parameter  340 . As will be described in more detail below (e.g., with respect to  FIGS. 5 and 6 ), each compression object  310  may also include a session identifier  350  and a dispatch reference  360 . 
     FIG. 4  shows a method of reconstructing a uniform resource locator (URL) from a dynamically compressed URL, in accordance with one embodiment of the invention. The token and dynamic query string parameters of a particular compressed URL are identified, at  410 . At  420 , the token is utilized to search a dynamic URL compression table. The compression object containing the matching token includes corresponding path and static query string parameters. At  430 , the reconstructed URL is generated by appending the dynamic query string parameters to the path and static query string parameters of the corresponding compression object. 
     FIG. 5  shows a block diagram of a network for implementing embodiments of the invention. The exemplary network includes a plurality of network devices  510 - 540  communicatively coupled by one or more communication channels  550 ,  560 . In one implementation, a network device  510  is a client device, a network device  520  is a web server, and network devices  530 - 540  each provide one or more resources (e.g., web applications). 
   Each network device (e.g., for example the web server  520 ) includes a bus  522  for communication information and instructions. One or more processors  524  are coupled to the bus  522  for processing information and instructions. One or more memory units  526  are also coupled to the bus  522  for storing information and instructions for the processor  524 . The memory unit  526  may include volatile memory (e.g., random access memory, static RAM, dynamic RAM, and the like), non-volatile memory (e.g., read only memory, programmable ROM, flash memory, EPROM, EEPROM, and the like), mass data storage (e.g., hard disk, optical disk, floppy disk, and the like), and the like. Optionally, the network device may include one or more peripheral devices (e.g., display, keyboard, pointing device, speaker, and the like)  529  coupled to the bus  522 . The network device also includes one or more network interfaces  528  coupled to the bus  522 . The network interface  528  provides for communicating with other network devices across a communication channel. 
   Certain processes and steps of embodiments of the invention are realized as a series of instructions (e.g., code) that reside on a computer-readable medium, such as the memory unit  526 , and are executed by the processor  524  of the network device (e.g., web server  520 ). When executed, the instructions cause the processor  524  to provide a dynamic uniform resource locator (URL) compression schema. 
   Upon connection (e.g., session binding) of the client device (e.g., wireless device)  510  to the web server  520 , the client device  510  sends a first request for content (e.g., HTML web page) to the web server  520 . The web server  520  generates a first response to the client device  510  that contains one or more URLs (e.g., links). In the course of generating the response, the dynamic URL compression schema of the web server  520  dynamically compresses the one or more URLs. 
   Each URL is compressed by identifying the path, static query string parameters and dynamic query string parameters. The web server  520  checks a dynamic URL compression table to determine if the particular combination of the path and static query string parameters (e.g., compression object) is already cached. If the particular combination of path and static query string parameters is cached, the web server  520  uses the associated token for dynamically compressing the particular URL. If the particular combination of path and static query string parameters is not cached, the web server  520  generates a unique token representing the particular combination of path and static query string parameters (e.g., compression object) and caches the token, path and static query string parameters in the dynamic URL compression table. The web server  520  appends the particular dynamic query string parameters to the associated token to form the compressed URL. Each such compressed URL is then sent as part of the content encoded in the first response sent to the client device  510 . 
   Each compression object cached in the dynamic URL compression table may also include a session identifier and/or a dispatcher reference. If the session is a cookie session, the session identifier is encoded in the cookie that accompanies the set of URLs of the response. If the session is a cookie-less session, the session identifier is encoded in each compressed URL of the response. The session identifier provides for client aware and/or device aware navigation. The dispatcher reference identifies the particular JSP, servelet, applet, common gateway interface, HTML page or the like to be used for dispatching the request of a particular resource represented by the URL. In an optional feature, a cache defeating value may also be encoded in each compressed URL of the response. 
   In one embodiment of the invention, a dynamic URL compression table is maintained for each user. Thus, the associated paths, static parameters and tokens (e.g., each compression object for a particular user) are cached in a separate dynamic URL compression table according to the user. Maintaining dynamic URL compression tables on a per user basis provides a measure of security that prevents a particular user&#39;s session from being exposed to other users. 
   Upon selection of a link (e.g., compressed URL in response) the client device  510  sends a second request containing a compressed URL selected from the first response. It is appreciated that one or more dynamic parameters of the selected compressed URL may be modified by the client device. However, the path and static query string parameters represented by the token of the selected compressed URL remain unchanged. 
   The dynamic URL compression schema of the web server  520  receives the compressed URL composed of the token and dynamic query string parameters. The token and session identifier of the compressed URL are utilized to determine the corresponding path and static query string parameters (e.g., compression object) from the dynamic URL compression table. The dynamic parameters are appended to the corresponding path and static query string parameters to form the reconstructed URL. The web server  520  is thereafter able to determine the requested resource from which to obtain the requested content represented. 
   If a dispatcher reference is part of the compression object, the corresponding dispatcher reference is utilized to determine the appropriate JSP, servelets applet, common gateway interface, HTML page or the like for handling the particular request for content represented by the URL. 
   Referring now to  FIGS. 6A and 6B , a computer implemented method of dynamically compressing a uniform resource locator (URL) and reconstructing the URL there from, in accordance with one embodiment of the invention, is shown. As depicted in  FIG. 6A , a dynamic URL compression schema compresses one or more URLs contained in content to be sent as a response (e.g., HTTP response). 
   At  605 , the dynamic URL compression schema receives content to be encoded as a response. The content includes one or more URLs. At  610 , each URL is parsed to determined the path, static query string parameters and dynamic query string parameters thereof. 
   At  615 , a dynamic URL compression table is searched to determine whether the particular combination of the path and static query string parameters (e.g., compression object), of each URL, is cached. If the particular combination of path and static query string parameters is cached, the associated token is retrieved, at  620 . If the particular combination of path and static query string parameters is not cached, a token uniquely identifying the combination is generated, at  625 . At  630 , the generated token and associated path and static query string parameters are cached. 
   At  635 , the corresponding dynamic query string parameters are appended to the corresponding token to generate each compressed URL. Each compressed URL corresponds to a particular URL of the content to be encoded in the response. 
   In a cookie session, the response is generated to include a cookie and the plurality of compressed URLs. The session identifier is encoded in the cookie of the response. In a cookie-less session, the response is generated to include a plurality of compressed URLs. The session identifier is encoded in each of the compressed URL of the response. The session identifier may be cached at  630 , along with the corresponding token, path and static query string parameters. If a dispatcher reference is utilized, the dispatcher reference may also be cached at  630 . 
   At  640 , the compressed URLs are encoded in the response. At  645 , the response is sent to a client device (e.g., in response to a request). Thus, the compressed URLs are sent as part of the content being sent by the web server in place of the URL. 
   As depicted in  FIG. 6B , the dynamic URL compression schema reconstructs a URL from a compressed URL contained in a request. At  655 , the dynamic URL compression schema receives a request containing a compressed URL from the second device (e.g., client device). The request may further include a cookie. A session identifier may optionally be encoded in the compressed URL or the cookie. At  660 , the compressed URL is parsed to determine a token and one or more dynamic query string parameters. 
   At  665 , the token is utilized to search the dynamic URL compression table. The compression object (e.g., record) having the matching token contains the corresponding path and static query string parameters. If the dynamic URL compression table also contains a session identifier, the session identifier of the request is utilized in addition to the token to match to a corresponding compression object in the dynamic URL compression table. 
   At  670 , the dynamic string parameters contained in the compressed URL are appended to the corresponding path and static query string parameters to generate a reconstructed URL. At  675 , the reconstructed URL is then dispatched for processing by an appropriate JSP. If the dynamic URL compression table also includes a dispatcher reference in the matching compression object, the corresponding dispatcher reference is utilized to dispatch the reconstructed URL to the appropriate JSP, servelet, applet, common gateway interface, HTML pages or the like. 
   Embodiments of the present invention provide for compressing URLs and reconstructing URLs from the compressed URLs. The compressed URLs of reduced size may be utilized in limited bandwidth applications, such as wireless application, to minimize the impact of URLs on the functionality of such applications. Accordingly, embodiments of the present invention reduce the overall bandwidth required for requests and responses in a network. Embodiments of the present invention also provide for generating client aware URLs. Accordingly, embodiments of the present invention enable navigating between java server pages of applications. 
   While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.