Patent Publication Number: US-9846649-B1

Title: Providing files with cacheable portions

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of and claims benefit of priority to U.S. patent application Ser. No. 13/035,721, filed Feb. 25, 2011, entitled “PROVIDING FILES WITH CACHEABLE PORTIONS,” which is hereby incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Client computing devices may request files, such as web pages, from one or more servers over a network. A client computing device that receives pages or other files from a server may locally store or cache the received files. The cached copies of the files may be presented for display again in the future from cache memory without sending a second request to the server, and without receiving the files from the server a second time. For example, a client computing device may receive from a server a page, such as a HyperText Markup Language (“HTML”) page, that include references to one or more image files or other files that are to be presented for display. The client computing device may then request the one or more image files from the appropriate server and present the image files for display, along with other content of the page. The client computing device may additionally store the one or more image files in a data store local to or accessible to the client computing device. These locally stored cached copies of the one or more image files may then be presented for display as part of a subsequently requested page that includes references to the same image files, provided that certain conditions are met. In this manner, the number of file requests to the server in order to display the subsequently requested page is less than if the client computing device requested the previously received images files a second time, rather than retrieve locally cached copies of the image files. However, if a subsequently requested file differs from a previously received file, the client computing device typically must receive the subsequently requested file in full. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  depicts an illustrative operating environment in which a client computing device may request one or more files from a file server, and may store portions of one or more of the received files in a cache data store. 
         FIG. 2A  is a block diagram illustrating a client computing device within the operating environment of  FIG. 1  requesting a first file from a file server, and storing a shared portion of the first file in a cache data store. 
         FIG. 2B  is a block diagram illustrating a client computing device within the operating environment of  FIG. 1  requesting a second file from the file server, and presenting the second file for display based on a modified second file received from the file server and the shared portion previously stored in the cache data store. 
         FIG. 3  depicts a general architecture of a file server for determining shared portions of files, and for sending files to a client computing device. 
         FIG. 4  is an illustrative user interface generated by the file server that includes shared portions of a page to be stored in the cache data store. 
         FIG. 5  is an illustrative user interface generated in part by the file server that includes shared portions of a page retrieved from the cache data store by the client computing device. 
         FIG. 6  is a flow diagram of an illustrative method implemented by the file server to modify a file to identify shared portions. 
     
    
    
     DETAILED DESCRIPTION 
     Generally described, aspects of the present disclosure relate to systems and methods for enabling a portion of a page or other file received from a server to be stored or cached by a client computing device, such that the client computing device may incorporate the stored portion into a subsequently received page or other file. As discussed above, existing systems may enable a client computing device to store a cache copy of an entire file, such as an HTML page or an image referenced in an HTML page. However, in order to optimize the delivery of an initial page or other file to a client computing device, developers often attempt to include as many elements as possible into a single file, such as by including inline code segments in an HTML file, rather than referencing smaller separate files that could potentially be separately cached by the client computing device. One reason that a developer may construct pages as a single file rather than as a smaller file that references other files is that a single file construction may require fewer Transmission Control Protocol (“TCP”) or Internet Protocol (“IP”) connections in order to deliver the total page content on the initial page load. A drawback to such an approach when used with existing systems, however, is that these inline elements can typically not be cached by the client computing device to be reused for subsequent page loads. Accordingly, subsequently requested pages that have elements or portions in common with a page previously received by the client computing device must typically be received in full (including the common or shared portions) as a result of each request. Aspects of the present disclosure enable a page or other file to be constructed in a manner that minimizes connection requests to a server, while also enabling one or more portions of the file to be separately stored as cache copies by the client computing device, such that the one or more portions may be reused by the client computing device by incorporating the portions into a subsequently requested page. 
     In certain embodiments, a file server as disclosed herein may receive a first request from a client system for a first file. In response to the first request, the file server may send to the client system the first file. The first file sent to the client system may include a cache identifier identifying a shared portion of content of the first file, where the shared portion of content is included in both the first file and at least one other file accessible via the file server. The file server may then receive a request from the client system for a second file that includes the shared portion of content that was included in the first file. The file server may then determine whether the client system has stored the shared portion of content of the first file. If the file server determines that the client system has not stored the shared portion of content, the file server may send the second file to the client system, where the second file sent to the client system includes the shared portion of content. If instead the file server determines that the client system has stored the shared portion of content, the file server may then send to the client system a modified second file that includes the cache identifier, but does not include the shared portion of content. The client system may then determine the full content of the second file based on the modified second file and the previously stored shared portion of content. 
     In some embodiments, the cache identifier may be added by a developer or creator of the file. In other embodiments, the cache identifier may be added to the first and/or second file automatically as a result of the file server determining shared portions of content that appear in two or more files stored in a file data store associated with the file server. For example, the file server may automatically determine a shared portion of content by comparing content of the first file and the second file, and optionally additional files. The file server may then automatically add the cache identifier to the first file, the second file, and/or other files that include the shared portion of content. 
     A “file” as used herein may refer to content of a variety of types, including content that may be streamed to a client computing device and/or assembled in response to a user request. A page, which may be one example of a file, may include text and/or code of various types, such as JavaScript, HTML, Cascading Style Sheets (“CSS”), etc. While an example of a file as a page may be used herein, it will be appreciated that a file may include, but is not limited to, audio data, video data, text data, and/or other forms of data or content. For example, a portion of streaming video content, such as an advertisement portion of a video feed, may be stored as a shared portion in a cache data store, such that the advertisement or other shared portion may be incorporated in a subsequently requested video file or stream without being received a second time from a server. 
       FIG. 1  depicts an illustrative operating environment  100  in which a client computing device  102  may request one or more files from a file server  120 , and then may store or “cache” portions of one or more of the received files in the cache data store  112 . The depicted environment  100  includes a client computing device  102  and a file server  120  communicatively connected by a network  108 , such as the Internet. Those skilled in the art will recognize that the client computing device  102  may be any of a number of computing devices that are capable of communicating over a network including, but not limited to, a laptop, personal computer, tablet computer, electronic book reader, personal digital assistant (PDA), hybrid PDA/mobile phone, mobile phone, and the like. In some embodiments, the client computing device  102  may include computer hardware and software components similar to those described below with respect to the file server  120 . 
     As further illustrated in  FIG. 1 , the file server  120  includes or communicates with a file data store  122 . The file data store  122  may include files of one or more types, including, but not limited to, pages (which may include code and other text to be interpreted or executed by a computing device, such as the client computing device  102 ), video files, audio files, etc., as discussed above. Those skilled in the art will appreciate that the file data store  122  may be local to the file server  120 , may be remote to the file server  120 , and/or may be a network-based service itself. As illustrated, the client computing device  102  includes or communicates with a cache data store  112 . The cache data store  112  may include shared portions of one or more files that have been received by the client computing device  102  from the file server  120 , and may include cache identifier information identifying each stored shared portion. Those skilled in the art will appreciate that the network  108  may be any wired network, wireless network or combination thereof. In addition, the network  108  may be a personal area network, local area network, wide area network, cable network, satellite network, cellular telephone network, etc., or combination thereof. Protocols and components for communicating via the Internet or any of the other aforementioned types of communication networks are well known to those skilled in the art of computer communications and, thus, need not be described in more detail herein. 
       FIG. 2A  is a block diagram illustrating the client computing device  102  within the operating environment  100  of  FIG. 1  requesting a first file from the file server  120  and storing a shared portion of the first file in the cache data store  112 . For purposes of this example, the “first file” refers to a file that is requested and received by the client computing device  102  prior to any shared portions of the file being stored in the cache data store  112 . As illustrated, the client computing device  102  sends a first file request to the file server  120 . The first file request may be, for illustrative purposes, a request for a page. The page may include code, such as HTML code, as well as other text. The client computing device  102  may send the first file request, for example, as a result of a page request generated by a web browser installed on the client computing device  102 . Once the file server  120  receives the first file request, the file server  120  may retrieve the first requested file from the file data store  122 . The file server  120  may then send the first requested file to the client computing device  102 . The first file sent to the client computing device  102  may include a cache identifier associated with a “shared portion” of the first file, which may be a portion of the first file that the file server  120  has determined is also included in one or more additional files stored in the file data store  122 . The presence of the cache identifier may indicate to the client computing device that the shared portion should be stored or cached by the client computing device  102 . The file server  120  may have made the determination that a shared portion is included in the first file based on comparing the content of files in the file data store  122 , as discussed below with reference to  FIG. 6 . In other embodiments, the cache identifier may have been added to the first file by an author or creator of the first file, an operator associated with the file server  120 , or another individual or entity associated with the file server  120  and/or the first file. An example of the manner in which a cache identifier may identify a shared portion of a file is discussed below with reference to  FIGS. 4 and 5 . 
     When the client computing device  102  receives the first file from the file server  120 , the client computing device  102  may present the first file. For example, if the first file is a page, video, or other file that may be displayed, the client computing device may present the first file for display. If the first file includes audio data, the client computing device may cause playback of the audio data. If the first file is a page that includes references to additional files, such as an image, a file containing additional code, a video, etc., the client computing device  102  may request the additional files from the file server  120  and/or one or more additional servers (not illustrated). The content of the page, optionally including additional files that are associated with or referenced by the page, may be presented for display, for example, as a user interface displayed via a navigation interface such as a web browser installed on the client computing device  102 . The client computing device  102  may store in the cache data store  112  the shared portion (or multiple shared portions) that are identified in the first file, as indicated by one or more cache identifiers or other indicators present in the first file. 
     The shared portion may be caused to be stored or cached in a data store, such as the cache data store  112 , by software operating on the client computing device, such as a web browser. For example, in some embodiments, a browser configured to identify and store shared portions of a file may have been previously installed on the client computing device  102 . Alternatively, a browser plug-in or other add-on software associated with a browser may be installed on the client computing device  102  in order to identify and store shared portions of a file. In other embodiments, code, such as JavaScript, included in the first page received from the file server  120  (or in an additional file received from the file server  120 ) may be executed by the client computing device  102  in order to determine shared portions of the first file and store the shared portions in a data store local to or accessible to the client computing device  102 . The information stored in the cache data store may include, for example, each shared portion in the first file, along with a cache identifier identifying each shared portion. In some embodiments, additional information associated with each shared portion may be stored in the cache data store  112 , such as an expiration day and/or expiration time associated with the shared portion. 
       FIG. 2B  is a block diagram illustrating the client computing device  102  within the operating environment  100  of  FIG. 1  requesting a second file from the file server  120 , and presenting the second file for display based on a modified second file received from the file server  120  and the shared portion previously stored in the cache data store  112 . For purposes of this example, the “second file” refers to a file that is requested and received by the client computing device  102  after at least one shared portion in the second file has been received by the client computing device  102  and stored in the cache data store  112 . For example, a given shared portion may be included in both the first file previously received by the client computing device  102  and the second file being requested. As illustrated, the blocks depicted in  FIG. 2B  occur after the blocks in  FIG. 2A  have occurred, although other files (not illustrated) may have been received by the client computing device  102  in between the first file described above with respect to  FIG. 2A  being received and the second file described below with respect to  FIG. 2B  being received. 
     As illustrated in  FIG. 2B , the client computing device  102  sends a second file request to the file server  120 . The second file request may be, for illustrative purposes, a request for a page after the client computing device has already received the first page from the file server  120 , as discussed above with reference to  FIG. 2A . Once the file server  120  receives the second file request, the file server  120  may retrieve the second requested file from the file data store  122 . The file server  120  may then determine whether the second requested file includes any shared portions that have been previously sent to and stored by the client computing device  102 . In some embodiments, the file server  120  may make such a determination, in part, by determining whether the second file retrieved from the file data store  122  includes any cache identifiers, and whether any of the shared portions associated with these cache identifiers have been previously sent to the client computing device  102 . In some embodiments, the file server may additionally determine whether the client computing device  102  is capable of recognizing and storing shared portions of files (not illustrated). For example, the file server  120  may receive information from the client computing device  102  indicating the capability of the client computing device  102  to store and retrieve shared portions (such as by indicating to the file server  120  version information of a browser operating on the client computing device  102 ). The client computing device  102  may additionally or alternatively send information to the file server  120  identifying each cache identifier for which the client computing device  102  has stored a corresponding shared portion in the cache data store  112  (which the client computing device  102  may store in one or more data stores as a “cookie” or other data file associated with a user&#39;s browsing history). In other embodiments, the file server  120  may assume that if a given shared portion and cache identifier were previously sent to the client computing device  102 , then the client computing device  102  has stored the shared portion and is capable of retrieving the shared portion from a local data store, such as the cache data store  112 , or from another data source other than the file server  120 . 
     If the file server  120  determines that the client computing device  102  has not previously cached or stored any portions of the second file, the file server may send the second file to the client computing device  102  (not illustrated). If instead the file server  120  determines one or more shared portions of the second file that have been previously cached or stored by the client computing device  102 , the file server  120  may create a modified second file. As will be discussed below with respect to  FIGS. 4 and 5 , the file server  120  may create the modified second file by including all of the content of the retrieved second file other than the shared portions that have been previously cached or stored by the client computing device  102 . The file server  120  may, in some embodiments, include in the modified second file the cache identifier corresponding to each previously cached shared portion in place of the shared portion itself, as will be discussed below. If the second file includes one or more previously cached shared portions and one or more shared portions that have not yet been cached by the client computing device  102 , the file server  120  may include, in the modified second file, the shared portion(s) that have not been previously cached, while not including the shared portion(s) that have been previously cached. Accordingly, the modified second file, and/or one or more additional files subsequently sent to the client computing device  102 , may include cache identifiers identifying previously cached content while also including additional shared portions of content to be cached or stored by the client computing device  102  (as well as corresponding cache identifiers). As will be appreciated, it is not necessary that the file server  120  actually store the modified second file. For example, in some embodiments, the modified second file may be sent to the client computing device  102  as it is constructed by the file server  120 . 
     As illustrated, the file server  120  may send the modified second file to the client computing device  102 . The modified second file may include cache identifiers identifying one or more shared portions previously sent to the client computing device  102  as part of a previously sent file (in this example, as part of the first file discussed above with reference to  FIG. 2A ). When the client computing device  102  receives the modified second file from the file server  120 , the client computing device  102  may retrieve from the cache data store  112  the shared portions corresponding to the cache identifiers included in the modified second file. The client computing device  102  may then determine the content of the second file by inserting the shared portions into the modified second file at the locations of the corresponding cache identifiers in the modified second file. Accordingly, the client computing device  102  may effectively recreate the full content of the second file that is stored in the file data store  122  based on the smaller, modified second file received from the file server  120  in combination with stored portions of one or more previously received files. The client computing device  102  may then present the content of the second file (as determined from the content of the modified second file and the retrieved shared portions) for display, playback, etc., as appropriate for the given file type. 
       FIG. 3  depicts a general architecture of the file server  120  illustrated in  FIG. 1 . The embodiment of file server  120  depicted in  FIG. 3  includes an arrangement of computer hardware and software components that may be used to implement aspects of the present disclosure. Those skilled in the art will appreciate that the file server  120  may include many more (or fewer) components than those shown in  FIG. 3 . It is not necessary, however, that all of these generally conventional components be shown in order to provide an enabling disclosure. As illustrated in  FIG. 3 , the file server  120  includes a network interface  306 , a processing unit  304 , an input/output device interface  320 , and a computer readable medium drive  307 , all of which may communicate with one another by way of a communication bus. As illustrated, the file server  120  is optionally associated with, or in communication with, a display  302 , and an input device  324 . The network interface  306  may provide the file server  120  with connectivity to one or more networks or computing systems. The processing unit  304  may thus receive information and instructions from other computing systems or services via a network. The processing unit  304  may also communicate to and from memory  310  and further provide output information for an optional display  302  via the input/output device interface  320 . The input/output device interface  320  may accept input from the optional input device  324 , such as a keyboard, mouse, digital pen, touch screen, or gestures recorded via motion capture. 
     The memory  310  contains computer program instructions that the processing unit  304  executes in order to implement one or more embodiments of the present disclosure. The memory  310  generally includes RAM, ROM and/or other persistent or non-transitory memory. The memory  310  may store an operating system  314  that provides computer program instructions for use by the processing unit  304  in the general administration and operation of the file server  120 . The memory  310  may further include other information for implementing aspects of the present disclosure. For example, in one embodiment, the memory  310  includes a user interface module  312  that facilitates generation of user interfaces (such as by providing instructions therefor) for display upon a computing device. For example, a user interface may be displayed via a navigation interface such as a web browser installed on the computing device. In addition, memory  310  may include or communicate with an auxiliary file data store  122 , discussed above. 
     In addition to the user interface module  312 , the memory  310  may include a caching module  325  that may be executed by the processing unit  304 . In one embodiment, the caching module  325  may be used to implement various aspects of the present disclosure, such as comparing one or more files to identify shared portions that may be cached by a client computing device, as described further below. In certain embodiments of the present disclosure, the client computing device  102  may include several components that operate similarly to the components illustrated as part of the file server  120 , including a user interface module, processing unit, computer readable medium drive, etc. 
       FIG. 4  is an illustrative user interface  400  generated by the file server  120  that includes shared portions  402 ,  404  and  406  to be stored by the client computing device  102  in the cache data store  112 . Illustrative user interface  400  may be presented for display, for example, on a browser operating on the client computing device  102 . User interface  400  may be considered to display the content of a first page, such as an HTML page, received from the file server  120 , as discussed above with reference to  FIG. 2A . The user interface  400  may include content determined by the client computing device  102  by interpreting and/or executing script or code within the first received page. The user interface  400  includes text content  401 , reading in part “Brand-X 4 GB Flash Memory Card.” For purposes of example, text content  401  may be considered unique to the first page (which is displayed in user interface  400 ), and was not designated as a shared portion to be separately stored for cache purposes in the cache data store  112 . In contrast, each of the content portions  402 ,  404  and  406  may have been, for purposes of example, designated in the received file as a shared portion by a cache identifier marking each of the content portions  402 ,  404  and  406 . For example, the text and/or code that caused the client computing device  102  to display the “Browse categories” content portion  404  may have been marked in the page received from the file server  120  as a shared portion to be separately cached in the cache data store  112  along with a cache identifier identifying the content portion  404 . For illustrative purposes, the first page received from the file server  120  may have included text or code similar to the following, which may indicate to the client computing device  102  that shared portion  406  should be stored in the cache data store  112 :
         &lt;CACHEABLE ACTION=save NAME=Footer EXPIRES=2011/03/01&gt;   © 2001-2011, Retailer.xyz, or its affiliates   &lt;/CACHEABLE&gt;       

     As a result of the above illustrative partial content of the first page received from the file server  120 , the client computing device  102  may store the shared text portion  406 , “© 2001-2011, Retailer.xyz, or its affiliates,” in the cache data store  112 , along with a cache identifier “Footer” that identifies the shared text portion  406 . The “Footer” cache identifier and associated illustrative HTML tags above may have been previously added automatically by the file server  120  to the first page, such as by the methods described below with reference to  FIG. 6 , or by an author or creator associated with the first page. The cache identifier may have been added, for example, because the text “© 2001-2011, Retailer.xyz, or its affiliates” may be included in a large number of different pages or other files stored in the file data store  122  associated with or accessible by the file server  120 . Similarly, the content portions  402  and  404  may be included in one or more additional pages or files stored in the file data store  122 . 
       FIG. 5  is an illustrative user interface  500  generated in part by the file server  120  that includes shared portions  502 ,  504  and  506  retrieved from the cache data store  112  by the client computing device  102 . Illustrative user interface  500  may be presented for display, for example, on a browser operating on the client computing device  102 . User interface  500  may be considered to display the content of a second or subsequent page, such as an HTML page, received from the file server  120 , as discussed above with reference to  FIG. 2B . For example, the second page, which is displayed in user interface  500 , may have been received by the client computing device  102  after the shared content portions  402 ,  404  and  406  discussed above with reference to user interface  400  have been stored in the cache data store  112 . As illustrated, content portions  502 ,  504  and  506  of user interface  500  are identical to content portions  402 ,  404  and  406 , respectively, of user interface  400 . Accordingly, the file server  120  may have sent to the client computing device a modified second page, rather than the second page stored in file data store  122 . The modified second page may have included the content displayed in content portion  501 , but not included the content displayed in content portions  502 ,  504  and  506 . For example, instead of sending the content portion  506 , which is identical to the content portion  406  previously stored by the client computing device  102 , the file server  120  may have included in the modified second page text or code similar to the following, which may indicate to the client computing device  102  that the shared portion previously identified with the cache identifier “Footer” should be retrieved from cache data store  112  and displayed: “&lt;CACHEABLE ACTION=retrieve NAME=Footer&gt;&lt;/CACHEABLE&gt;.” In response to receiving the modified second page, the client computing device may have retrieved the text “© 2001-2011, Retailer.xyz, or its affiliates” from the cache data store  112  based on the “Footer” cache identifier in the modified second page. The client computing device may then have caused display of the modified second page in user interface  500 , including shared portions  502 ,  504  and  506  retrieved from the cache data store  112 . 
       FIG. 6  is a flow diagram of an illustrative method  600  implemented by the file server  120  to modify a file to identify shared portions in the file. The illustrative method  600  may be implemented at least in part by the caching module  325 . While the method  600  is illustrated using the example of a single file (designated as “file X”) being compared to other files, in some embodiments, the illustrated method may be implemented by the file server  120  for each file in file data store  122 , or for a subset of the files. For example, in some embodiments, the file server  120  may modify each file in file data store  122  to identify shared portions on a periodic basis, such as nightly, weekly, etc. In other embodiments, the file server  120  may modify one or more files in file data store  122  to identify shared portions in response to a triggering event, such as the content of a file being changed or a new file being stored in the file data store  122 . In other embodiments, the illustrated method  600  may be implemented for file X in response to a client computing device, such as the client computing device  102 , requesting file X from the file server  120 . As discussed above, in some embodiments, instead of or in addition to the file server  102  modifying files to identify shared portions as illustrated in method  600 , shared portions may be explicitly marked or indicated by an author or creator of each file. 
     The method  600  begins at block  602 , then proceeds to block  604 , where the file server  120  retrieves file X from file data store  122  or another data store. File X may be any file stored in the file data store  122 , or in another data store, that the file server  120  will compare to other files to determine whether any common content or shared portions are present in the file X. At block  606 , the file server  120  determines whether there are additional files to compare to file X (for example, files that should be compared to file X, but which have not yet been compared to file X during the current implementation of illustrative method  600 ). If the file server  120  determines at block  606  that there are no additional files to compare to file X, the method ends at block  620 . If instead the file server  120  determines at block  606  that there are one or more additional files to compare to file X, the file server  120  proceeds to block  608 , where the file server retrieves from file data store  122  the next file to be compared to file X. 
     Once the file server  120  has retrieved the next file, the file server  120  proceeds to block  610 . At block  610 , the file server  120  compares the content of file X and the content of the retrieved file to determine shared portions, if any. File X and the retrieved file may be compared, for example, according to known document comparison techniques. The result of the comparison at block  610 , in some embodiments, may be one or more portions of content (such as text content, audio content, video content, etc.) that were determined by the file server  120  to be included in both file X and the retrieved file. The illustrative method  600  then proceeds to block  612 , where the file server  120  determines whether to mark or tag any shared portions that were determined at block  610 . As used herein, “marking” a shared portion may generally refer to storing some indication that a certain portion of a file is a shared portion that may be separately cached by a client computing device when the file is received by the client computing device from file server  120 . In some embodiments, the file server  120  may mark every shared portion determined at block  610 . In other embodiments, only shared portions of a certain length or size (such as a predetermined minimum number of characters, words, lines, bytes, etc.) may be marked by the file server  120 . In some embodiments, the file server  120  may only mark shared portions if the shared portions occur in at least a certain number of files stored in file data store  122 , in which case the file server may increase a counter for a given shared portion of content for each retrieved file that is found by the file server  120  to include the shared portion (not illustrated in method  600 ). In other embodiments, the file server  120  may only mark shared portions of content that are included in frequently requested files or pages, or may generally consider the relative number of client requests for a given file when determining whether to mark a shared portion that is included in the file. 
     If the file server  120  determines at block  612  not to mark any shared portions (or if no shared portions were determined at block  610 ), the method proceeds to block  606  to determine whether there are additional file to compare to file X. Alternatively, if the file server  120  determines at block  612  that the file server  120  should mark one or more shared portions, the method  600  proceeds to block  614 . At block  614 , the file server  120  may modify file X and/or the retrieved file to include a cache identifier or other indication of a cacheable portion for each shared portion to be marked. In some embodiments, the cache identifier may include unique identification information that is automatically generated by the file server  120 . For example, the cache identifier may include a unique number or letter sequence for each shared portion, such that each time the file server marks the same shared portion in different files, the file server uses the same unique cache identifier. For example, the file server  120  may include in the file data store  122 , or another data store, cache association information associating each cache identifier that the file server  122  has marked in any file, along with an associated shared portion of content for each cache identifier. When the file server  120  determines that a shared portion found in file X has already been marked in one or more other files, the file server may retrieve the appropriate cache identifier from the cache association information stored in file data store  122  and include it in file X. If the file server  120  determines that the given shared portion found in file X has not been marked in any files previously, the file server  120  may create a new cache identifier that has not been used previously. The file server  120  may then add this new cache identifier to file X and update the stored cache association information to include the new cache identifier and the associated shared portion. 
     For illustrative purposes, consider that the shared portion determined at block  610  is the text “Frequently used text.” At block  614 , the file server  614  may modify this portion of text in file X and/or the retrieved file to read “&lt;CACHEABLE NAME=P123&gt; Frequently used text &lt;/CACHEABLE&gt;,” where the cache identifier “P123” has been automatically generated by the file server  120 . In other embodiments, marking file X may include removing the shared portion itself from file X, and replacing the shared portion with the corresponding cache identifier. In such embodiments, the file server  120  may place the shared portion back into the file X when the file X is requested by a client computing device that has not yet cached or stored the given shared portion. Once the file server  120  has modified file X and/or the retrieved file to include any cache identifiers, the method  600  proceeds to block  606  to determine whether there are additional files to compare to file X. 
     The above methods discussed throughout the present disclosure may result in smaller files being sent from the file server  120  to the client computing device  102 , because previously cached shared portions may be sent only once, rather than being sent again for subsequent file requests. The above methods may additionally or alternatively result in decreasing the number of connections or requests from the client computing device  102  to the file server  120 , because content may be included in a single file, where the same content might otherwise be split into multiple files in order to take advantage of the existing full file caching of other systems. As will be appreciated, enabling caching of portions of a file and other aspects of the present disclosure may be implemented for a variety of file types. For example, a news video file or content stream may include a frequently used introduction portion or stock footage that is shared between multiple files or feeds, and which may be treated as a shared portion as discussed herein. As another example, streaming audio data, such as a radio program, may include advertisements that are reused and may be separately cached according to aspects of the present disclosure. Accordingly, many types of content accessible over a network may benefit from aspects of the present disclosure. 
     It is to be understood that not necessarily all objects or advantages may be achieved in accordance with any particular embodiment described herein. Thus, for example, those skilled in the art will recognize that certain embodiments may be configured to operate in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. 
     All of the processes, including but not limited calculation processes, described herein may be embodied in, and fully automated via, software code modules executed by one or more general purpose computers or processors. The code modules may be stored in any type of computer-readable medium or other computer storage device. Some or all the methods may alternatively be embodied in specialized computer hardware. In addition, the components referred to herein may be implemented in hardware, software, firmware or a combination thereof. 
     Conditional language such as, among others, “can,” “could,” “might” or “may,” unless specifically stated otherwise, are otherwise understood within the context as used in general to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. 
     Any process descriptions, elements or blocks in the flow diagrams described herein and/or depicted in the attached figures should be understood as potentially representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or elements in the process. Alternate implementations are included within the scope of the embodiments described herein in which elements or functions may be deleted, executed out of order from that shown, or discussed, including substantially concurrently or in reverse order, depending on the functionality involved as would be understood by those skilled in the art. 
     It should be emphasized that many variations and modifications may be made to the above-described embodiments, the elements of which are to be understood as being among other acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.