Abstract:
Embodiments include retrieving data of a web page from a remote system in response to a request for the web page. It is determined that the web page is indicated in a data structure that indicates web pages not to be cached in a cache of a web browser on a data processing system. The data structure and the cache of the web browser are distinct from each other. The web page is presented with the web browser using the data retrieved from the remote system. The data of the web page is prevented from being cached in the cache of the web browser in accordance with said determining that the web page is indicated in the data structure that indicates web pages not to be cached in the cache of the web browser on the data processing system.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates generally to an improved data processing system and in particular to a method and apparatus for processing data. Still more particularly, the present invention relates to a method, apparatus, and computer instructions for managing the caching of data by a browser on a client. 
     2. Description of Related Art 
     The Internet, also referred to as an “internetwork”, is a set of computer networks, possibly dissimilar, joined together by means of gateways that handle data transfer and the conversion of messages from a protocol of the sending network to a protocol used by the receiving network. When capitalized, the term “Internet” refers to the collection of networks and gateways that use the TCP/IP suite of protocols. 
     The Internet has become a cultural fixture as a source of both information and entertainment. Many businesses are creating Internet sites as an integral part of their marketing efforts, informing consumers of the products or services offered by the business or providing other information seeking to engender brand loyalty. Many federal, state, and local government agencies are also employing Internet sites for informational purposes, particularly agencies which must interact with virtually all segments of society such as the Internal Revenue Service and secretaries of state. Providing informational guides and/or searchable databases of online public records may reduce operating costs. Further, the Internet is becoming increasingly popular as a medium for commercial transactions. 
     Currently, the most commonly employed method of transferring data over the Internet is to employ the World Wide Web environment, also called simply “the Web”. Other Internet resources exist for transferring information, such as File Transfer Protocol (FTP) and Gopher, but have not achieved the popularity of the Web. In the Web environment, servers and clients effect data transaction using the Hypertext Transfer Protocol (HTTP), a known protocol for handling the transfer of various data files (e.g., text, still graphic images, audio, motion video, etc.). The information in various data files is formatted for presentation to a user by a standard page description language, the Hypertext Markup Language (HTML). In addition to basic presentation formatting, HTML allows developers to specify “links” to other Web resources identified by a Uniform Resource Locator (URL). A URL is a special syntax identifier defining a communications path to specific information. Each logical block of information accessible to a client, called a “page” or a “Web page”, is identified by a URL. The URL provides a universal, consistent method for finding and accessing this information, not necessarily for the user, but mostly for the user&#39;s Web “browser”. A browser is a program capable of submitting a request for information identified by an identifier, such as, for example, a URL. A user may enter a domain name through a graphical user interface (GUI) for the browser to access a source of content. The domain name is automatically converted to the Internet Protocol (IP) address by a domain name system (DNS), which is a service that translates the symbolic name entered by the user into an IP address by looking up the domain name in a database. 
     Some of the features that provide a dynamic and adaptive nature for Web browsers used in surfing or browsing the Internet also are features that have high security concerns for individuals concerned about personal privacy. These features include cookies and page caching. 
     For example, when the user visits a credit card Website to view personal data, cookies and cached Web pages concerning the user&#39;s visit may be cached onto the hard drive of the computer being used. Subsequent visits to other Websites may encounter fraudulent or mischievous sites that may wish to view or steal personal data from the user&#39;s hard drive. 
     Some solutions for this issue include Web designers designing sites to prevent cookie or page caching to occur on the client computer. An example is a Java application that displays personal data in the application itself and not on the Web browser. Further, third-party plug-ins that flush all cookies and cache at set intervals also have been used. Additionally, one may manually set purge requests in the Web browser. One problem with programs providing for purging of sensitive data at set intervals or with the user manually purging data from the browser cache is that all of the data is purged. In some cases, such an event is undesirable. Further, in between events in which the browser cache is purged, a visit to a malicious Website may still result in the theft of personal or confidential data. 
     Therefore, it would be advantageous to have an improved method, apparatus, and computer instructions for managing the caching of data by a browser on a data processing system. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method, apparatus, and computer instructions for managing caching of data by a browser. A request is received to retrieve a Web page. The request includes location information for the Web page. A determination is made as to whether a match is present in a data structure for the location information. In response to a match being present, the caching of data for the Web page is prevented or cached on a temporary basis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the present invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a pictorial representation of a data processing system in which the present invention may be implemented in accordance with a preferred embodiment of the present invention; 
         FIG. 2  is a block diagram of a data processing system in which the present invention may be implemented; 
         FIG. 3  is a diagram illustrating components used in managing the caching of data by a browser in accordance with a preferred embodiment of the present invention; 
         FIGS. 4A and 4B  are diagrams illustrating a graphical user interface for managing the caching of data by a browser in accordance with a preferred embodiment of the present invention; 
         FIG. 5  is a flowchart of the process for defining URL and domain names in accordance with a preferred embodiment of the present invention; and 
         FIG. 6  is a flowchart of a process for managing caching of data by a browser in accordance with a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference now to the figures and in particular with reference to  FIG. 1 , a pictorial representation of a data processing system in which the present invention may be implemented is depicted in accordance with a preferred embodiment of the present invention. A computer  100  is depicted which includes system unit  102 , video display terminal  104 , keyboard  106 , storage devices  108 , which may include floppy drives and other types of permanent and removable storage media, and mouse  110 . Additional input devices may be included with personal computer  100 , such as, for example, a joystick, touchpad, touch screen, trackball, microphone, and the like. Computer  100  can be implemented using any suitable computer, such as an IBM eServer computer or IntelliStation computer, which are products of International Business Machines Corporation, located in Armonk, N.Y. Although the depicted representation shows a computer, other embodiments of the present invention may be implemented in other types of data processing systems, such as a network computer. Computer  100  also preferably includes a graphical user interface (GUI) that may be implemented by means of systems software residing in computer readable media in operation within computer  100 . 
     With reference now to  FIG. 2 , a block diagram of a data processing system is shown in which the present invention may be implemented. Data processing system  200  is an example of a computer, such as computer  100  in  FIG. 1 , in which code or instructions implementing the processes of the present invention may be located. Data processing system  200  employs a peripheral component interconnect (PCI) local bus architecture. Although the depicted example employs a PCI bus, other bus architectures such as Accelerated Graphics Port (AGP) and Industry Standard Architecture (ISA) may be used. Processor  202  and main memory  204  are connected to PCI local bus  206  through PCI bridge  208 . PCI bridge  208  also may include an integrated memory controller and cache memory for processor  202 . Additional connections to PCI local bus  206  may be made through direct component interconnection or through add-in connectors. In the depicted example, local area network (LAN) adapter  210 , small computer system interface SCSI host bus adapter  212 , and expansion bus interface  214  are connected to PCI local bus  206  by direct component connection. In contrast, audio adapter  216 , graphics adapter  218 , and audio/video adapter  219  are connected to PCI local bus  206  by add-in boards inserted into expansion slots. Expansion bus interface  214  provides a connection for a keyboard and mouse adapter  220 , modem  222 , and additional memory  224 . SCSI host bus adapter  212  provides a connection for hard disk drive  226 , tape drive  228 , and CD-ROM drive  230 . Typical PCI local bus implementations will support three or four PCI expansion slots or add-in connectors. 
     An operating system runs on processor  202  and is used to coordinate and provide control of various components within data processing system  200  in  FIG. 2 . The operating system may be a commercially available operating system such as Windows XP, which is available from Microsoft Corporation. An object oriented programming system such as Java may run in conjunction with the operating system and provides calls to the operating system from Java programs or applications executing on data processing system  200 . “Java” is a trademark of Sun Microsystems, Inc. Instructions for the operating system, the object-oriented programming system, and applications or programs are located on storage devices, such as hard disk drive  226 , and may be loaded into main memory  204  for execution by processor  202 . 
     Those of ordinary skill in the art will appreciate that the hardware in  FIG. 2  may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash read-only memory (ROM), equivalent nonvolatile memory, or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in  FIG. 2 . Also, the processes of the present invention may be applied to a multiprocessor data processing system. 
     For example, data processing system  200 , if optionally configured as a network computer, may not include SCSI host bus adapter  212 , hard disk drive  226 , tape drive  228 , and CD-ROM  230 . In that case, the computer, to be properly called a client computer, includes some type of network communication interface, such as LAN adapter  210 , modem  222 , or the like. As another example, data processing system  200  may be a stand-alone system configured to be bootable without relying on some type of network communication interface, whether or not data processing system  200  comprises some type of network communication interface. As a further example, data processing system  200  may be a personal digital assistant (PDA), which is configured with ROM and/or flash ROM to provide non-volatile memory for storing operating system files and/or user-generated data. 
     The depicted example in  FIG. 2  and above-described examples are not meant to imply architectural limitations. For example, data processing system  200  also may be a notebook computer or hand held computer in addition to taking the form of a PDA. Data processing system  200  also may be a kiosk or a Web appliance. 
     The processes of the present invention are performed by processor  202  using computer implemented instructions, which may be located in a memory such as, for example, main memory  204 , memory  224 , or in one or more peripheral devices  226 - 230 . 
     The present invention provides an improved method, apparatus, and computer instructions for selectively caching data by a browser. A browser is an application used to navigate or view information or data in a distributed database, such as the Internet or the World Wide Web. The mechanism of the present invention provides for selectively caching data for Web pages based on a URL or domain name for the Web page in the illustrative examples. The user may enter URLs or domain names that are stored as a list such that any references to links matching the URLs or domain names result in the Web page being displayed, but all cookies and cached pages are flushed or cleared from the data processing system without any caching occurring. 
     Depending on the options selected, if a match between a domain name or a particular URL and those in the list occurs, caching of data associated with a retrieved Web page is prevented. If a match does not occur, then caching occurs normally for the browser. 
     With reference now to  FIG. 3 , a diagram illustrating components used in managing the caching of data by a browser is depicted in accordance with a preferred embodiment of the present invention. In this illustrative example, browser  300  may retrieve Web pages, such as Web page  302 , from various Websites on the Internet. Typically, browser  300  caches information within cache  304 . This information includes previously retrieved Web pages, which may be stored in Web pages  306  and cookies received from various Websites which may be stored in cookies  308 . Web page  302  is, for example, an HTML file which is displayed by browser  300  and is saved in cache  304  as a cache file. This cache file is typically named with a randomly generated unique identifier. For example, a file named MCFIHTML may be stored in cache  304  as cache3F266B4100113BA6.htm. This type of naming convention avoids conflict with other files that may have the same name. As a result, selectively flushing files by viewing the file names in cache  304  is difficult because of the naming convention. 
     Currently, a user may flush Web pages and cookies from cache  304  through selecting an Internet option provided through browser  300 . Additionally, a user also may set browser  300  to prevent any caching of Web pages and acceptance of cookies in cache  304 . The mechanism of the present invention adds additional features with respect to caching of data by browser  300 . Specifically, the mechanism of the present invention allows for selective caching of data in cache  304  based on a domain name or URL for a retrieved Web page, such as Web page  302 . 
     This selective caching process may be implemented in caching plug-in  310  in the illustrative examples. A plug-in is a program that is associated with browser  300  to provide for additional functionality. Typically, this additional functionality provides for audio, graphic, or video features. The mechanism of the present invention implements a selective caching process within caching plug-in  310  to control the manner in which data is cached in cache  304 . 
     In the illustrative examples, caching plug-in  310  may prevent caching of data for any Web page. Additionally, an option for preventing caching of data based on specific URLs and domain names also may be set through caching plug-in  310 . If a no cache option is selected, all caching of data within cache  304  is prevented when browser  300  retrieves Web pages. A selection of a URL match results in caching plug-in  310  preventing the caching of data within cache  304  if the URL for a retrieved Web page matches a URL within URL list  312 . A selection to prevent caching based on domains results in caching plug-in  310  preventing the caching of data in cache  304  in response to the domain for Web page  302  matching a domain within domain list  314 . Thereafter, Web page  302  is displayed on the screen for browser  300 , but not saved to the disk with such a match. Instead, the data is cleared. 
     URL list  312  and domain list  314  may be maintained by caching plug-in  310  in a fashion similar to the manner in which browser  300  maintains a list of bookmarks. In the illustrative examples, the cookies and cache pages are sent to a “/dev/null” and thus flushed from the data processing system, rather than being cached or stored anywhere within the data processing system. This particular option causes the file to be presented on browser  300 , but the actual file is written into a “/dev/null”, which is a name used to refer to a “black hole” in operating systems. For example, instead of the file cache3F266B4100113BA6.htm being written into the standard cache directory, in cache  304 , browser  300  writes the file to an alternative directory, rather than the standard cache directory. This type of file writing occurs when a URL or domain for a Web page is identified as being on URL list  312  or domain list  314 . 
     Of course, other mechanisms may be used. One other mechanism is an “erase the next to last cache” mechanism, which causes the file to be named to a common cache name, rather than using a unique name. For example, instead of using the name cache3F266B4100113BA6.htm, a common cache name, such as delete_next.htm may be used. This name is used for every file. As a result, the next Web page from a URL or domain name on URL list  312  or domain name  314  is saved using delete_next.htm, causing the previously cached file to be erased. 
     Another option involves writing and then erasing the file for the Web page. When a do-not-cache URL or domain is detected, the Web page is displayed onto the browser. In this illustrative example, the file to be cached is saved as cache_short_life.htm. Then, after this file is written to the disk, the file is erased as the next action. This feature may be used in the instance in which a browser will not display or pull down Web pages unless the browser also can write to the cache. This mechanism allows the browser to write to the cache. With this mechanism, after this write-display by the browser finishes, the mechanism of the present invention erases the file in this particular embodiment. 
     In this manner, a user may save cached information for a site visited before and after the visit to the sensitive site. The user does not have to clear the entire cache to clear sensitive information from the disk cache. Further, this mechanism also avoids having a user to identify locations in which cookies and pages are cached and attempt to delete that information by trying to identify cookies or data associated with Web pages from a sensitive Website. 
     Turning now to  FIGS. 4A and 4B , diagrams illustrating a graphical user interface for managing the caching of data by a browser is depicted in accordance with a preferred embodiment of the present invention. In  FIG. 4A , browser window  400  is illustrated in which menu  402  is displayed in response to a selected user input, such as a right-click to a pointing device with pointer  404  being located within browser window  400 . 
     Menu  402  includes the following options: “No cache”  406 , “Always match”  408 , “Any match”  410 , and “Add”  412 . “No cache”  406  results in preventing any data from being cached in response to the retrieval of Web pages from different Websites. A selection of “Always match”  408  means that if content is requested from a URL that exactly matches a URL listed in a URL list, then the content will be displayed, but data is not cached in the data processing system. Instead, the data is cleared from the data processing system. 
     A selection of “Any match”  410  results in a Web page being retrieved from a URL containing a match to a domain name listed within a domain list being displayed, but the data is not saved or cached. Instead, the data is cleared from the data processing system after the Web page is displayed on the browser screen. 
     In this manner, a user may selectively prevent caching of data from Websites that are considered to be sensitive. The user may identify these Websites by selecting “Add”  412 . A selection of this option allows the user to enter domain names and URLs for sensitive Websites or Web pages that should not be cached. 
     In  FIG. 4B , browser window  400  provides an option for entering URL and domain name information into lists for selectively caching data through window  414 . This window is presented in response to a selection of “Add”  412  from menu  402 , in  FIG. 4A . In this illustrative example, a domain name or URL may be entered within text field  416 . The user may add the domain name or URL to a URL list or domain list based on the selection of controls  418  and  420  respectively. 
     When the user is ready to add the entry, the user may select “Okay” button  422 . If the user desires to cancel the entry, a selection of “Cancel” button  424  may be made from window  414 . If control  418  is selected, the URL is entered into a URL list, such as URL list  312  in  FIG. 3 . The selection of control  420  results in the domain name entered into text field  416  being saved in a domain list, such as domain list  314  in  FIG. 3 . 
     With reference now to  FIG. 5 , a flowchart of the process for defining URL and domain names is depicted in accordance with a preferred embodiment of the present invention. The process illustrated in  FIG. 5  may be implemented in a plug-in, such as caching plug-in  310  in  FIG. 3 . 
     The process begins by receiving a user input to define an entry in a list (step  500 ). This user input may be, for example, a selection of “Add”  412  in menu  402  in  FIG. 4A . In response to receiving this user input, a window is displayed (step  502 ). This window provides an interface for a user to enter information for entry in a list. The window may be implemented using a window, such as window  414  in  FIG. 4B . 
     Thereafter, user input is received (step  504 ). In step  504 , the user input is a selection of a button indicating that entry into the window has been completed. A determination is made as to whether the user input is to save information from the window (step  506 ). In the illustrative example in  FIG. 4B , the user input is to save data if “Okay” button  422  is selected. The user input is to cancel the operation or not save data if “Cancel” button  424  in  FIG. 4B  is selected. If data is to be saved, a determination is made as to whether all of the fields have been completed (step  508 ). If all of the fields have been completed, a determination is made as to whether the user has entered a URL for the entry (step  510 ). 
     If the user has not entered a URL, then the data is a domain name and the domain name is saved in a domain list (step  512 ) with the process terminating thereafter. Referring back to step  510 , if the information entered by the user is a URL, then the URL is saved in a URL list (step  514 ) with the process terminating thereafter. 
     With reference again to step  506 , if the user has decided not to save the data entered into the window, the process terminates. This termination of the process occurs without saving any data that may have been entered into the window. Turning back to step  508 , if all of the fields have not been completed, a prompt to complete entry of the fields is made (step  516 ) with the process then returning to step  502  as described above. 
     With reference now to  FIG. 6 , a flowchart of a process for managing caching of data by a browser is depicted in accordance with a preferred embodiment of the present invention. The process illustrated in  FIG. 6  may be implemented in a plug-in, such as caching plug-in  310  in  FIG. 3 . 
     The process begins by receiving a user input requesting a Web page (step  600 ). This request may be through a selection of a link or by a user entering a URL into an address field in the browser. A determination is made as to whether the user has selected an always match option (step  602 ). An always match option is one in which an exact match between the URL for the requested Web page and an entry in a URL list is required. 
     If the user has selected an always match option, a determination is made as to whether the URL for the Web page has a match with an entry in the URL list (step  604 ). If a match is present, the Web page is retrieved and caching is prevented with this retrieval (step  606 ). Thereafter, the Web page is presented (step  608 ). 
     With reference again to step  604 , if the URL does not match, then the Web page is retrieved (step  610 ) with the process then proceeding to step  608  as described above. In this case, caching of information for the Web page is not prevented. 
     With reference again to step  602 , if an always match option has not been selected, a determination is made as to whether an any match option has been selected (step  612 ). If an any match option has been selected, a determination is made as to whether the domain name in the URL for the Web page matches an entry within a domain list (step  614 ). If a match is present, the process proceeds to step  606  as described above. Otherwise, the process retrieves the Web page without preventing caching of information as described in step  610 . 
     With reference again to step  612 , if an any match option has not been selected, a determination is made as to whether a no cache option has been selected (step  616 ). If a no cache option has been selected, the process proceeds to step  606  as described above. Otherwise, the process proceeds to step  610  to retrieve the Web page with normal caching occurring. 
     Caching may be prevented in a number of different ways depending on the particular implementation. In the illustrative examples, caching is prevented by directing data for the Web page to a “/dev/null” causing the data to be flushed from the data processing system. In this illustrative embodiment, the data is not stored for the Web page. Instead, data is sent to the graphics adapter or other adapters for presentation to the user. Otherwise, data is not saved to the hard disk or stored in a buffer or memory for later use. As a result, if the user selects a different Web page and wishes to return to the previous Web page, all information has to be retrieved from the Website. In an alternative embodiment, data may be temporarily cached in a memory in which this data is flushed as soon as the user retrieves another Web page. 
     Thus, the present invention provides an improved method, apparatus, and computer instructions for managing the caching of data associated with Web pages. The mechanism of the present invention allows a user to enter URLs or domain names that are stored by a browser or plug-in associated with the browser. As a result, any reference or selection of Web pages matching the URLs or domain names will result in those Web pages being displayed on the browser screen. However, all cookies, cached pages, and other information associated with these entries are flushed from the data processing system and not saved within a browser cache or any other cache in the data processing system. 
     In the illustrative examples, the caching control allows for the prevention of any caching to occur. The other additional options include requiring an exact match to a URL or requiring a match to a domain name. Further, the mechanism of the present invention also may be applied to a match to any text that is entered. For example, if the user enters “ABC”, then any URL containing the string “ABC” will initiate a process to prevent caching of data for that page. As a result, the user may enter a stream that may be part of a URL or part of a domain name and prevent caching of data for any Web pages containing that string in the URL. 
     Thus, the user may save cached information for non-sensitive sites, while information for sensitive sites is cleared from the data processing system. This mechanism avoids the user having to clear the cache of all information. Further, this mechanism avoids a user having to manually search folders for information associated with a sensitive site and having to manually delete files containing sensitive data. 
     It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media, such as a floppy disk, a hard disk drive, a RAM, CD-ROMs, DVD-ROMs, and transmission-type media, such as digital and analog communications links, wired or wireless communications links using transmission forms, such as, for example, radio frequency and light wave transmissions. The computer readable media may take the form of coded formats that are decoded for actual use in a particular data processing system. 
     The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.