JP5241418B2 - COMMUNICATION SYSTEM AND COMMUNICATION METHOD, CLIENT DEVICE AND ITS CONTROL METHOD - Google Patents

Description

  The present invention relates to a communication system and a communication method, and a client apparatus and a control method thereof, and more particularly, to a communication system and a communication method for handling updated content data, and a client apparatus and a control method thereof.

  In recent years, network environments such as the Internet have become widespread, and huge amounts of data exist in a distributed manner on the network. In order to efficiently collect a huge amount of data existing on this network, it is effective to acquire update information of these data that exist in a distributed manner. As a method for acquiring update information, for example, a method is known in which a computer connected to a network polls a computer holding data on the network to inquire whether there is update information and acquires update information. ing.

  At this time, if the polling interval is shortened, update information can be acquired with higher accuracy. However, particularly when there is a lot of data that is updated at an interval much longer than the polling interval, traffic in the network is wasted. If the polling interval is too long, for example, the accuracy of the update information acquired for data that is updated multiple times within the polling interval is low.

  As a polling interval control method for improving the accuracy of update information, Patent Literature 1 describes a technique for controlling a polling interval based on an access history for data collection. That is, according to Patent Document 1, the date and time when data that has been updated is accessed is stored as an access history based on a communication result for collecting data. Then, the regularity regarding the date and time when the data is updated is analyzed based on the access history, and the polling interval is controlled based on the analysis result.

  Patent Document 2 describes a technique for controlling a polling interval based on information on the latest update date and time among update information of collected data. That is, according to Patent Document 2, when the latest update date / time information is included in the collected data, the latest update date / time is extracted and stored. The regularity related to the date and time when the information is updated is analyzed based on the accumulated update date and time, and the polling interval is controlled based on the analysis result.

JP 09-034812 A Japanese Patent Laid-Open No. 10-049553

  According to the methods described in Patent Document 1 and Patent Document 2 described above, the information stored to control the polling interval is the access date or the latest update date. Therefore, when the collected data is updated at an interval shorter than the polling interval, there is a problem that the polling interval corresponding to the update date of the collected data cannot be controlled.

  For example, if the collection data is updated at a timing that is exactly half of the initial polling interval, the accumulated update information becomes the polling interval (double the data update interval). Cannot be controlled according to

  Further, according to the methods described in Patent Document 1 and Patent Document 2, in order to analyze the regularity regarding the update date and time, it is necessary to perform polling a plurality of times and accumulate the access date and time and update date and time. Therefore, there is a problem that the polling interval corresponding to the update date / time of the collected data cannot be controlled until the access date / time and the update date / time are accumulated in an amount necessary for analysis after performing polling a certain number of times.

  Therefore, an object of the present invention is to provide a communication system and a communication method capable of adaptively controlling the timing of acquiring update information of data existing on a network, an information processing apparatus, and a control method thereof. is there.

In order to solve the above-described problem, a first invention is a communication system in which a server device and a client device are communicably connected via a network, and the server device is connected to the client via the network. Content data management means for managing an update history of content data accessed by the apparatus; and generation means for generating status information indicating an update status of the content data based on the update history managed by the content data management means; And the client device requests the status information from the server device, and the requesting device should make the request next based on the status information acquired by the request from the requesting device. Determining means for determining the timing; and the required timing at the timing determined by the determining means. And control means for causing the request to the means, the generation unit of the server device, in response to the request, generates the update history as the state information, the determination unit of the client device, the update The timing is determined based on an update date and time interval included in the history, and the request unit of the client device performs the request by adding an information acquisition date and time indicating the date and time when the status information was acquired last time, and the server device The generation unit generates an update history indicating an update date and time after the information acquisition date as the status information, and the generation unit of the server device generates the status information in response to the request. And a first interval and a second interval longer than the first interval or any one of them are set and added to the state information, and the clock is The determination unit of the client device may be configured such that an interval between the timing at which the request is made by the request unit and the timing at which the next request should be determined based on the state information is shorter than the first interval. Determines again the timing at which the next request should be made based on the result obtained by adding the first interval to the time indicated by the timing at which the request is made by the request means, and the interval from the timing at which the next request should be made Is longer than the second interval, the second timing is added to the time indicated by the timing at which the request is made by the requesting means, and the timing at which the next request should be made is determined again. This is a featured communication system.

In the second invention, the client device and the server device having content data management means for managing the update history of the content data accessed by the client device via the network are connected to be communicable via the network. In the communication method of the communication system, the client device transmits a request for status information indicating the update status of the content data managed by the content data management means to the server device. And a generation step in which the server device generates status information indicating the update status of content data based on the update history managed by the content data management means in response to the request from the client device; In response to the request from the client device, a device A transmission step of transmitting the state information generated in the generation step to the client device via the network; and the client device transmits the request from the server device in response to the request transmitted in the request transmission step. And determining the timing for transmitting the request for the status information in the request transmission step based on the status information, and the server device stores the update history in response to the request. Generated as status information, the client device determines the timing based on an update date and time interval included in the update history, and the client device adds an information acquisition date and time indicating the date and time when the status information was previously acquired. The server device makes an update after the information acquisition date and time in the update history. An update history indicating time is generated as the state information, and the server device generates the state information in response to the request, and a first interval and a second interval longer than the first interval or these Either one of them is set and added to the status information, and the client device has a timing when the request is made by the request means and a timing when the request is to be made next determined based on the status information. When the interval is shorter than the first interval, the timing at which the next request should be made is determined again based on the result obtained by adding the first interval to the time indicated by the timing at which the request is made by the request means. In the case where the interval from the timing at which the next request is to be made is longer than the second interval, the second interval is added to the time indicated by the timing at which the request is made by the request means. The communication method is characterized in that the next timing for making a request is determined again based on the above .

According to a third aspect of the present invention, there is provided a client device that accesses, via a network, a server device that manages a content data update history, and the update state of the content data managed by the server device is indicated. Requesting means for requesting status information to be indicated to the server device, and acquiring the status information generated by the server device in response to a request by the requesting device, and the requesting device should then make the request Determining means for determining timing; and control means for causing the requesting means to make the request at the timing determined by the determining means, wherein the determining means performs the status information in the server device in response to the request. The timing is determined based on an update date and time interval included in the update history generated as described above, and the requesting unit acquires the status information last time. The determination unit performs the request by adding an information acquisition date and time indicating the received date and time, and the determination unit generates the status information in the server device in response to the request, based on the information acquisition date and time transmitted together with the request. The timing is determined using an update history indicating an update date and time after the information acquisition date in the update history, and the determination unit includes the status information generated by the server device in response to the request. , Based on the first interval for the request added to the state information and / or the second interval longer than the first interval, the timing at which the request is made by the request means, When the interval with the timing at which the next request is to be determined, which is determined based on the state information, is shorter than the first interval, the first interval is set to the time when the request is made by the request means. Based on the result added to the time indicated by the timing, the next timing for making the request is determined again, and the second interval when the interval from the next timing for making the request is longer than the second interval. The client device is characterized in that the timing at which the next request is made is determined again based on the result obtained by adding to the time indicated by the timing at which the request is made by the request means .

According to a fourth aspect of the present invention, there is provided a client device control method for accessing content data managed together with an update history to a server device via a network, wherein the content data managed by the server device is updated. A requesting step for requesting status information indicating a status to the server device, and the requesting step makes the request next based on the status information generated by the server device in response to the request by the requesting step. And a control step for causing the requesting step to make the request at the timing determined by the determining step. In the determining step, the server device responds to the request with the state. The timing based on an interval of update dates and times included in the update history generated as information In the request step, the request is made by adding an information acquisition date and time indicating the date and time when the status information was acquired last time. In the determination step, the status information is generated as the status information in the server device in response to the request. Further, the timing is determined using an update history indicating an update date and time later than the information acquisition date and time among the update histories based on the information acquisition date and time transmitted together with the request, and in the determination step, according to the request And the status information generated by the server device and the first interval for the request added to the status information and / or the second interval longer than the first interval. The interval between the timing at which the request is made in the request step and the timing at which the next request is determined based on the state information is based on the first request. If it is shorter than the interval, the timing at which the next request should be made is determined again based on the result obtained by adding the first interval to the time indicated by the timing at which the request was made in the request step, and the request is made next. If the interval with the power timing is longer than the second time interval, the timing at which the next request should be made is determined based on the result of adding the second time interval to the time indicated by the timing at which the request is made in the request step. It is a control method characterized by determining again .

  Since the present invention has the above-described configuration, it is possible to adaptively control the timing for acquiring update information of data existing on the network.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an exemplary configuration of a communication system applicable to the present invention. A computer 101 on the user side is connected to the Internet 100. On the computer 101 on the user side as a client device, browser software 110 described later and an information acquisition program 111 for performing processing on the computer 101 side in the embodiment of the present invention operate. Note that a plurality of client apparatuses 101 may be connected to the Internet 100.

  A server device 102 is connected to the Internet 100. In the example of FIG. 1, one server device 102 is shown connected to the Internet 100, but a plurality of server devices 102 may be connected to the Internet 100. In this way, the server apparatus 102 and the computer 101 are connected via the Internet 100 so that they can communicate with each other.

  The server apparatus 102 includes a computer having a communication function with the Internet 100 and a storage medium such as a hard disk connected to or built in the computer. In the server apparatus 102, a content management unit 120, a content database 121, and an information database 122 are configured by a program operating on a computer and a predetermined area on a storage medium.

  The server device 102 can publish resource metadata as content data to the Internet 100 in accordance with the rules of RSS. The resource data is multimedia information such as still image data, moving image data, and audio data, and is reproduced using the browser software 110 of the computer 101. RSS is an abbreviation for RDF Site Summary or Really Simple Syndication, and the name varies depending on the version. In the following description, it is assumed that RSS is an RDF Site Summary of version RSS 1.0. Note that RDF is an abbreviation for Resource Description Framework, and is a framework for expressing metadata of data.

  RSS is one of the standards for efficiently distributing resource titles, summary, and headline information such as URI information targeted by the summary on the Internet 100, and is described using XML. Note that XML is an abbreviation for Extensible Markup Language, and can be defined for each data using a start tag <> and an end tag </>. The RSS data is stored in the content database 121 in the server apparatus 102 and is given a unique URI (Universal Resource Identifier) and managed by the content management unit 120. That is, the server apparatus 102 manages RSS data as content data. A service that provides data using RSS is generally called an RSS feed.

  The information provided by the RSS feed will be schematically described. In RSS, RSS data has at least a channel element and an item element. In the channel element, RSS basic information is described. The channel element includes the title of the channel, the URI of the Web site to be summarized by RSS, the outline of the channel, and the table of contents of the resource described in the item element in the channel element. The resource table of contents includes a URI for each resource.

  In the item element, the title, URI, and summary of the resource are described for each resource described in the item element in the channel element. The URI for each resource described in the item element is basically the same value as the URI for each resource described in the item element in the channel element.

  The user receives an RSS feed service using application software called an RSS reader, and accesses RSS data using a URI provided by the RSS feed service. Then, according to the description of the channel element and item element of the RSS data, the RSS reader displays a title and a summary for the resource described in the item element, and also shows a URI for the resource. A user can quickly find desired resource information based on RSS data obtained by an RSS feed using an RSS reader without actually accessing the website.

  In the following, unless otherwise specified, content data refers to RSS data provided by an RSS feed. In addition, it is assumed that the browser software 110 operating on the user computer 101 is an RSS reader.

  In the server apparatus 102, the information database 122 stores update information of content data stored in the content database 121. The update information stored in the information database 122 is generated by the content management unit 120. The update information of the content data is stored in the information database 122. The content management unit 120 and the information database 122 correspond to content data management means, and the content management unit 120 corresponds to generation means.

  As an example, for each resource described in the item element of content data, that is, RSS data, when the information indicated by the URI of the resource is updated, the content management unit 120 updates the resource summary and the like accordingly, Update RSS data. The update information of the RSS data is stored in the information database 122 by the content management unit 120, and the management information in the information database 122 is updated.

  In the example of FIG. 1, the content database 121 is shown to be directly connected to the server apparatus 102, but this is not limited to this example. That is, the content database 121 may be connected to another server device connected to the Internet 100. The content database 121, the information database 122, and the content management unit 120 can also be distributed on the Internet 100 in a distributed manner.

  FIG. 2 shows an exemplary configuration of the computer 101 on the user side. In FIG. 2, a CPU 210, a RAM 211 and a ROM 212, and a graphics controller 213 are connected to a bus 201. The CPU 210 as the request unit, the determination unit, the adjustment unit, and the control unit starts up the system using the RAM 211 as a work memory based on a program stored in the ROM 212 in advance. The CPU 210 reads program data recorded in advance on a hard disk 222 to be described later, expands the program data in the RAM 211, and controls each unit of the computer 101 based on the program data expanded on the RAM 211.

  The graphics controller 213 is connected to the display device 214, converts the display control signal output from the CPU 210 into a signal that can be displayed by the display device 214, and outputs the signal to the display device 214. The display device 214 uses, for example, an LCD (Liquid Crystal Display) as a display element.

  An input interface (I / F) 220, a hard disk 222, a drive device 223, and a communication interface (I / F) 224 are further connected to the bus 201. The input interface 220 is connected to a keyboard 221A and a pointing device 221B. A mouse or a touch pad can be applied to the pointing device 221B. Signals output from the keyboard 221 </ b> A and the pointing device 221 </ b> B are passed to the CPU 210 via the input interface 220.

  The hard disk 222 is used as a hard disk drive (HDD) including a hard disk body that is a recording medium itself and a drive device for driving the hard disk. The hard disk 222 records the above-described program for operating the CPU 210, and can store various data generated by the computer 101 and input to the computer 101.

  The drive device 223 can be loaded with a recordable type recording medium such as a DVD (Digital Versatile Disc) or a CD (Compact Disc), and reads / writes data from / to the loaded recording medium. Of course, a read-only DVD or CD-ROM may be loaded into the drive device 223. However, the present invention is not limited to this, and the drive device 223 may be equipped with a rewritable nonvolatile memory, and data may be read from and written to the nonvolatile memory. Further, the drive device 223 may be compatible with a flexible disk.

  The communication I / F 224 is for connecting to an external network using a predetermined protocol. In the example of FIG. 2, the communication I / F 224 corresponds to TCP / IP (Transmission Control Protocol / Internet Protocol) and controls connection with the Internet 100. The CPU 210 can communicate with other devices connected on the Internet 100 via the communication I / F 224.

  In such a configuration, the browser 110 and the information acquisition program 111 described above are operated by the CPU 210 based on program data recorded in advance on the hard disk 222. Here, the browser 110 and the information acquisition program 111 are described as being independent software, but these may be realized as separate functions within a single software. Further, the information acquisition program 111 may be resident on the RAM 211 and executed in the background with respect to the execution of other programs.

  The information acquisition program 111 can access the data indicated by the link information registered in advance using a protocol such as HTTP and acquire the status information of the data. Then, the obtained state information is analyzed, and when the update of the data is permitted, it can be displayed on the display device 214 and notified to the user, for example. Not limited to this, the information acquisition program 111 may automatically register update information of data obtained as a result of analyzing the state information in a database or the like.

  FIG. 3 is a flowchart schematically showing acquisition processing of an example of data state information according to the embodiment of the present invention. In step S10, the user computer 101 sends a request to the server apparatus 102 having the content data specified by the pre-registered link information by polling, and status information indicating the status of the content data is requested. (Required). The link information registered in advance is a URI for receiving, for example, RSS feed update information.

  In step S <b> 11, the server apparatus 102 generates status information in response to the request, and returns the status information of the requested content data to the computer 101. As the status information of the content data, update history information indicating the update history of the content data can be used.

  The state information returned from the server apparatus 102 is received by the computer 101. The computer 101 determines whether the corresponding content data has been updated based on the received status information (step S12). For example, the computer 101 can determine whether content data has been updated based on the current time and the received status information. If it is determined that the content data has been updated, the process proceeds to step S13. Also, if it is the first request for the status information of the content data, the process proceeds to step S13.

  In step S13, the user is notified that the content data has been updated by, for example, a predetermined display on the display device 214 of the computer 101. However, the present invention is not limited to this, and the computer 101 may automatically register the database. When an update notification is made to the user, the process proceeds to step S14.

  In step S14, the received state information is analyzed in the computer 101, and a polling interval for next requesting the state information of the content data is obtained. Then, the process proceeds to step S15, and the status information acquisition scheduled date and time, which is the date and time indicating the next request timing for the status information of the content data, is obtained from the obtained polling interval.

  On the other hand, if it is determined in step S12 described above that the content data has not been updated, the process proceeds to step S16. In step S16, the polling interval is set to a predetermined fixed value in the computer 101. Not limited to this, a value designated by the user for the computer 101 may be used as the polling interval. When the polling interval is set, the date and time when status information is scheduled to be acquired next time is obtained based on the set polling interval. The status information acquisition scheduled date and time is determined by the date and time when the status information thus obtained is scheduled to be acquired next time.

  When the state information acquisition scheduled date / time determined in step S15 or step S16 is reached as described above, the computer 101 performs the processing from step S10 again to update the status information acquisition scheduled date / time.

  FIG. 4 shows an example of the management structure of the update history in the server apparatus 102. The update history of the content data is associated with the data management information 400 for identifying each content data managed by the server apparatus 102 and the data update information 401 indicating the update date and time of the content data managed by the data management information 400 Configured. The data management information 400 and the data update information 401 are generated by the content management unit 120 and stored in the information database 122.

  The data management information 400 is formed by associating a unique ID for each piece of content data managed by the server apparatus 102 with identification information for identifying the content data managed on the server apparatus 102 on the client (computer 101) side. . ID is an abbreviation for Identification. For example, the URI of the content data can be used as the identification information. The data update information 401 is formed by associating an ID with the update date / time of the content data corresponding to the ID, and is added each time the content data is updated.

  The server apparatus 102 can obtain the update history of the content data corresponding to the identification information by searching the data update information 401 using the ID as a key.

  Although illustration is omitted, the data management information 400 may include the content data itself in addition to the identification information for identifying the content data. The file path information may be included. Still other attribute information relating to the content data can be included in the data management information 400.

  FIG. 5 shows an example of link management information 500 held on the computer 101 side. The link management information 500 is generated for each content data by the CPU 210 based on information input to the computer 101 by the user, for example. Here, it is assumed that one link management information 500 corresponds to one RSS feed. The CPU 210 and the link management information 500 constitute content data information management means.

  In the example of FIG. 5, the link management information 500 includes a management ID 501, a name 502, link information 503 indicating content data, link information 504 indicating status information of the content data, information acquisition date / time 505, and status information acquisition scheduled date / time 506. Consists of. The management ID 501 is a unique ID for each link management information 500 for the computer 101 to identify the link management information 500. For example, serial numbers can be generated in the order of generation of the link management information 500 and used as the management ID 501. The name 502 is information for the user to identify the link management information 500.

  The link information 503 is a URI of content data corresponding to the link management information 500, and is, for example, a URI of an RSS feed corresponding to the link management information 500. The link information 504 is a URI of state information generated for the content data indicated by the link information 503 in the server apparatus 102. Taking FIG. 4 as an example, the URI of the data management information 400 can be used as the link information 504.

  The information acquisition date and time 505 is information indicating the latest date and time when the status information indicated by the link information 504 registered in the link management information 500 is acquired. Further, the status information acquisition scheduled date and time 506 indicates the status information acquisition scheduled date and time obtained in step S15 or step S16 in the flowchart of FIG. 3 described above.

  As an example, the user registers the URI of the RSS feed that he / she wants to receive in the link management information 500 as link information 503. At the same time, the user registers the URI of the status information of the content data in the link management information 500 as the link information 504. It is assumed that the URI of the status information of the content data is transmitted from the server apparatus 102 to the computer 101 when receiving an RSS feed service, for example.

  In addition, a name for identifying the link management information 500 is given to the link management information 500 and registered in the link management information 500. The management ID 501 is automatically set in the computer 101. The link management information 500 generated in this way is stored in the hard disk 222 of the computer 101, for example. The user repeats the registration operation for the link management information 500 for each RSS feed to receive the service.

  In the example of FIG. 5, link information 503 indicating content data and link information 504 indicating content data status information are respectively registered in the link management information 500. It is not limited. For example, when the data management information 400 includes content data, the link information 503 indicating the content data can be omitted.

  As described above, according to this embodiment, using the status information generated based on the history of updates made to the content data on the server device 102 side, the polling interval for obtaining the status information next is obtained. ing. Therefore, for example, even when the content data is updated at an interval shorter than the previously obtained polling interval, the computer 101 can know the timing at which the content data was updated. Therefore, even if the next update of the content data is performed at an interval shorter than the previous polling interval, the timing for obtaining the next state information can be obtained appropriately.

  Further, according to this embodiment, the computer 101 determines whether or not the content data held by the server apparatus 102 has been updated using the state information generated by the server apparatus 102 based on the update history of the content data. ing. Therefore, the computer 101 repeatedly accesses the server device 102 to obtain the timing for acquiring the next state information without storing the access history for the content data and the update date / time of the content data on the computer 101 side. be able to.

  The acquisition process of an example of the data state information according to the embodiment of the present invention will be described more specifically with reference to FIGS. FIG. 6 is a flowchart illustrating an example of processing on the computer 101 side. FIG. 7 is a flowchart showing an example of processing performed on the server apparatus 102 side in response to the processing according to the flowchart of FIG. FIG. 8 schematically shows an example of state information transmitted from the server apparatus 102 to the computer 101.

  In FIG. 6, in step S20, the CPU 210 acquires the number of link management information 500 registered in the computer 101, and initializes a loop variable to zero. In step S <b> 21, the CPU 210 compares the loop variable and the registered number of link management information 500. As a result of the comparison, if the loop variable is smaller than the registered number, the process proceeds to step S22.

  In step S22, the link management information 500 corresponding to the loop variable is acquired by the CPU 210 as a processing target. The process proceeds to step S23, and the status information acquisition scheduled date and time 506 in the link management information 500 acquired in step S22 is compared with the processing date and time, that is, the current date and time. If the status information acquisition scheduled date and time 506 indicates the past from the processing date and time, or if the status information acquisition scheduled date and time 506 matches the processing date and time, the process proceeds to step S24. On the other hand, if the status information acquisition scheduled date and time 506 indicates the future from the processing date and time, the process proceeds to step S30 described later.

  In step S24, the link information 504 indicating the status information of the content data in the processing target link management information 500 is referred to, and a request is made for the URI indicated by the link information 504. In response to the received request, the server apparatus 102 that has received this request performs the process illustrated in FIG.

  With reference to FIG. 7, the server apparatus 102 identifies the data management information 400 based on the request (step S40). For example, if the data identification information included in the data management information 400 is a URI, the data management information 400 having data identification information that matches the requested URI is searched. In the next step S41, the server apparatus 102 acquires the data update information 401 associated with the identified data management information 400. Then, state information is generated based on the acquired data update information 401 (step S42), and the generated state information is returned to the computer 101 that is the transmission source of the request.

  Note that the server apparatus 102 may generate state information each time content data is updated. The generated state information is held in the server apparatus 102 as a file. In this case, the server apparatus 102 refers to this file when status information is requested from the computer 101 in step S24 in the flowchart of FIG.

  FIG. 8 shows an exemplary configuration of status information transmitted from the server apparatus 102 to the computer 101. In the example of FIG. 8, the state information is described using XML. A tag <UPDATE> and a tag </ UPDATE> indicate that this data relates to the update date / time of the content data. In addition, information indicating the update date and time in the data update information 401 is listed in a portion between the tag <DATE> and the tag </ DATE>.

  In the example of FIG. 8, after the content data corresponding to this state information is registered in the server apparatus 102, the first update date and time is assumed to be 0:00 on January 1, 2007, and four times in a 25-hour cycle after registration. It shows that an update is taking place.

  In the example of FIG. 8, the state information is described using XML. However, this is not limited to this example, and the update history may be described in another format as the state information. The update history information and other information may be combined into status information, or it may be possible to embed the update history information in content data. The format of the update date and time, the XML tag name, etc. are examples, and other formats and other tag names may be used.

  The description returns to the flowchart of FIG. 6, and the computer 101 receives the status information returned from the server apparatus 102 (step S24). When the computer 101 acquires content data status information, the process proceeds to step S25. In step S25, based on the acquired status information and the information acquisition date and time 505 in the link management information 500 to be processed, the content data corresponding to the status information between the date and time indicated by the information acquisition date and time 505 and the processing date and time. It is determined whether or not updating has been performed.

  If it is determined that the content data has not been updated, the process proceeds to step S29. In step S29, in the computer 101, the polling interval is set to a predetermined fixed value. Not limited to this, a value designated by the user for the computer 101 may be used as the polling interval. When the polling interval is set, the state information acquisition scheduled date and time is determined based on the set polling interval. And a process transfers to step S30 mentioned later.

  On the other hand, if it is determined in step S25 that the content data has been updated, the process proceeds to step S26. In step S26, the user is notified that the content data has been updated by, for example, a predetermined display on the display device 214 of the computer 101. However, the present invention is not limited to this, and the computer 101 may automatically register the database. When the user is notified of the update, the process proceeds to step S27.

  In step S27, the received state information is analyzed in the computer 101, and a polling interval for next requesting the state information of the content data is obtained. When the polling interval is obtained, the process proceeds to step S28. In step S28, the status information acquisition scheduled date and time, which is the date and time indicating the next timing for requesting the status information of the content data, is determined from the determined polling interval. For example, the latest update date and time indicating the latest update date and time made for the content data is obtained from the status information, and the time indicated by the polling interval obtained in step S27 is added to the latest update date and time. Find the acquisition date and time. The obtained status information acquisition scheduled date and time is stored in the RAM 211, for example.

  If the state information acquisition scheduled date and time is obtained in step S28, the process proceeds to step S30, and the loop variable is incremented. Then, the process returns to step S21, and the same process is performed on the next link management information 500. The status information acquisition scheduled date and time obtained by this processing is sequentially stored in the RAM 211, for example.

  If the loop variable becomes a value equal to or greater than the number registered in the link management information 500 in step S21 described above, the process proceeds to step S31. In step S31, the status information acquisition scheduled date and time indicating the date and time closest to the processing date and time is selected from the status information acquisition scheduled date and time acquired in step S28. The selected status information acquisition scheduled date and time is determined as a new status information acquisition scheduled date and time 506 in the link management information 500. Then, the process proceeds to step S32, and the timer of the computer 101 is set so that the process from step S20 described above is started at this new state information acquisition scheduled date and time 506.

  As an example, it is assumed that the link information corresponding to the state information illustrated in FIG. 8 described above is registered in the computer 101 after 4 o'clock on January 5, 2007, which is the latest update date and time of the state information. . The computer 101 can acquire the status information by the first access to the server device 102 regarding the status information. In this acquired state information, the update date and time of the corresponding content data is described as a history. Therefore, the computer 101 can calculate the content data update cycle based on the acquired state information. Therefore, the computer 101 can adaptively set the next access time to the server apparatus 102.

  As the update cycle, for example, an average value of update intervals obtained from the update history can be used. In this case, the date and time obtained by adding the value of the update cycle to the latest update date and time described in the update history can be used as the status information acquisition scheduled date and time 506.

  As another method for calculating the update cycle, linear approximation based on the update history and pattern comparison can be considered. Further, the update cycle may be obtained from the difference between the latest update date and time and the update date and time by the update immediately before the latest update. In this case, it is conceivable to use the date and time when the difference is added to the latest update date and time as the status information acquisition scheduled date and time 506.

  The computer 101 can determine whether the corresponding content data has been updated based on the status information acquired as described above. Based on the determination result, the content data existing on the Internet 100 can be efficiently collected by selectively accessing the updated content data.

  In the above description, the content data is described as an RSS feed. However, this is not limited to this example. For example, each resource described as an item element in RSS data can be handled as content data. In this case, the server apparatus 102 has data management information 400 and data update information 401 for the item element. Similarly, in the link management information 500 held by the computer 101, for example, data link information 503 is a URI of a resource described as an item element.

  Also, there are cases where RSS tags can be expanded, as in RSS 2.0. In this case, the update history can be acquired by acquiring the RSS data itself by expanding and setting the update history in the RSS data.

  Furthermore, in the above description, the computer 101 has been described as selecting one status information acquisition scheduled date and time for a plurality of registered link management information 500, but this is not limited to this example. In other words, the status information acquisition scheduled date and time can be determined for each of the plurality of link management information 500. For example, a timer is set for each of the status information acquisition scheduled dates and times determined each time the processing from step S24 to step S28 or step S29 is performed. In this way, the computer 101 can set a polling interval for each content data.

<First Modification>
Next, a first modification of the embodiment of the present invention will be described. In the first modification, when requesting content data status information from the computer 101 to the server device 102, the computer 101 requests information indicating the date and time when the content data status information was previously acquired from the server device 102. Send with.

  An example of data status information acquisition processing according to the first modification will be described with reference to FIGS. FIG. 9 shows a configuration of an example of management information that the computer 101 side has to manage link information according to the first modification. FIG. 10 is a flowchart illustrating an example of processing on the computer 101 side. FIG. 11 is a flowchart illustrating an example of processing performed on the server apparatus 102 side in response to the processing according to the flowchart of FIG.

  As illustrated in FIG. 9, in the first modified example, management information update information 510 indicating the update date and time of the link management information 500 with respect to the link management information 500 similar to that described in FIG. 5. Are associated and configured.

  An example of processing on the computer 101 side will be described with reference to FIG. The process illustrated in FIG. 10 corresponds to the processes in steps S24 to S29 in the flowchart of FIG. 6 described above. Hereinafter, the processing on the computer 101 side according to the first modification is considered to be obtained by replacing the processing in steps S24 to S29 in the flowchart of FIG. 6 described above with the processing in steps S100 to S109 in the flowchart of FIG. The

  Prior to the processing according to the flowchart of FIG. 10, the computer 101 performs the processing of steps S20 to S23 in the flowchart of FIG. First, initialization of a loop variable and the number of registered link management information 500 are acquired (step S20). Further, link management information 500 is acquired (step S22), and the status information acquisition scheduled date and time 506 in the acquired link management information 500 is compared with the processing date and time (step S23). If it is determined that the status information acquisition scheduled date and time 506 indicates the past of the processing date and time, or if the status information acquisition scheduled date and time 506 match, the process proceeds to step S100 in FIG.

  In step S100, the computer 101 acquires the information acquisition date and time 505 in the link management information 500 acquired in step S22 of FIG. 6 described above. That is, in step S100, the computer 101 acquires information indicating the date and time when the request for the status information was last performed for the content data for which the status information is requested.

  The computer 101 confirms the information acquisition date and time 505, and if it is determined that the status information has been acquired in the past for the content data, the process proceeds to step S102. In step S102, the link information 504 in the link management information 500 acquired in step S22 of FIG. 6 is referred to, and an information state is requested for the URI indicated by the link information 504. At this time, the information acquisition date and time 505 acquired in step S100 is added to the request and transmitted to the server apparatus 102.

  On the other hand, if it is determined in step S101 that state information has not been acquired in the past for the content data, the process proceeds to step S103. In step S103, the link information 504 in the link management information 500 acquired in step S22 of FIG. 6 is referred to, and an information state is requested for the URI indicated by the link information 504. At this time, the information acquisition date 505 is not added.

  In response to the status information request from the computer 101 in step S102 or step S103, the server apparatus 102 performs a process whose example is shown in FIG. That is, the server apparatus 102 identifies the data management information 400 based on the request (step S120). If the data identification information included in the data management information 400 is a URI, the data management information 400 having the data identification information that matches the requested URI is searched. In the next step S121, the server apparatus 102 acquires the data update information 401 associated with the identified data management information 400.

  Then, in the next step S122, it is determined whether or not the information acquisition date and time 505 is added to the status information request transmitted from the computer 101. If it is determined that the information acquisition date 505 is not added, the process proceeds to step S123. In step S123, state information is generated using all the data update information 401 acquired in step S121. The generated state information is returned to the computer 101 that is the transmission source of the request.

  On the other hand, if it is determined in step S122 that the information acquisition date and time 505 is added to the request for status information, the process proceeds to step S124. In step S124, status information is generated using data update information indicating a date and time later than the information acquisition date and time 505 added to the request from the data update information 401 acquired in step S121. The generated state information is returned to the computer 101 that is the transmission source of the request.

  Returning to the flowchart of FIG. 10, the computer 101 receives the state information returned from the server apparatus 102. Based on the acquired status information and the information acquisition date and time 505 of the link management information 500, the content data corresponding to the status information is updated between the date and time indicated by the information acquisition date and time 505 and the processing date and time. It is determined whether or not (step S104).

  If it is determined that the content data has not been updated, the process proceeds to step S109. For example, if the acquired status information does not include information indicating the date and time when the data was updated, it can be determined that the content data has not been updated. In step S109, the polling interval is set to a predetermined fixed value in the computer 101. Not limited to this, a value designated by the user for the computer 101 may be used as the polling interval. When the polling interval is set, the state information acquisition scheduled date and time is determined based on the set polling interval. Then, the process exits a series of processes according to the flowchart of FIG. 10 and proceeds to step S30 of FIG.

  On the other hand, if it is determined in step S104 that the content data has been updated, the process proceeds to step S106. In step S106, the user is notified that the content data has been updated by, for example, a predetermined display on the display device 214 of the computer 101. However, the present invention is not limited to this, and the computer 101 may automatically register the database. When an update notification is made to the user, the process proceeds to step S107.

  In step S107, the received state information is analyzed in the computer 101, and a polling interval for next requesting the state information of the content data is obtained. Then, the process proceeds to step S108, and the status information acquisition scheduled date and time, which is the date and time indicating the next request timing for the status information of the content data, is obtained from the obtained polling interval. The obtained status information acquisition scheduled date and time is stored in the RAM 211, for example. Then, the process exits a series of processes according to the flowchart of FIG. 10 and proceeds to step S30 of FIG.

  As described above, in the first modification, when the computer 101 requests status information for certain content data, the computer 101 requests the information acquisition date 505 indicating the date and time when the status information was previously acquired for the content data. Append. On the server device 102 side, status information is generated based on data update information that is newer than the information acquisition date 505 based on the information acquisition date 505 added to the request. Therefore, the data size of the status information transmitted from the server apparatus 102 is reduced, and the load on the traffic on the Internet 100 can be reduced.

<Second Modification>
Next, a second modification of this embodiment will be described with reference to FIGS. This second modification is an example in which the server apparatus 102 obtains an average update interval of content data based on the update history information of the content data, and generates state information using this average update interval.

  FIG. 12 is a flowchart illustrating an example of processing when the server apparatus 102 generates state information according to the second modification. The server apparatus 102 identifies the data management information 400 based on the request from the computer 101 in step S24 of FIG. 6 (step S50). If the data identification information included in the data management information 400 is a URI, the data management information 400 having the data identification information that matches the requested URI is searched. In the next step S51, the server apparatus 102 acquires the data update information 401 associated with the identified data management information 400.

  In the next step S52, an average value of intervals at which the content data is updated based on the acquired data update information 401 is obtained. Then, state information is generated using information indicating the obtained average update interval. The generated state information is returned by the server apparatus 102 to the computer 101 that is the transmission source of the request.

  FIG. 13 shows an example of state information generated according to the flowchart of FIG. In the example of FIG. 13, the state information is described using XML. A tag <UPDATE> and a tag </ UPDATE> indicate that this data relates to content data update information. In addition, information indicating the latest update date and time of the corresponding content data on the server apparatus 102 is described in a portion between the tag <LAST_UPDATE> and the tag </ LAST_UPDATE>. Furthermore, information indicating the average update interval of the content data is described in a portion between the tag <AVERAGE> and the tag </ AVERAGE>.

  In the example of FIG. 13, the content data corresponding to this state information was updated on the server device 102 at 4:00 on January 5, 2007, and the content is averaged at intervals of 25 hours. It shows that the data has been updated.

  As an example, it is assumed that the link information corresponding to the state information illustrated in FIG. 13 described above is registered in the computer 101 after 4 o'clock on January 5, 2007, which is the latest update date. The computer 101 can acquire this status information by the first access from the computer 101 to the server apparatus 102. In the acquired state information, information indicating the latest update date and time of the corresponding content data and information indicating the average update interval are described.

  The computer 101 can use the average update interval described in the state information as the content data update cycle. The date and time obtained by adding the value of the update cycle to the latest update date and time described in the status information is used as the status information acquisition scheduled date and time 506. The update cycle of the content data can be calculated based on the acquired state information. Therefore, the computer 101 can adaptively set the next access time to the server apparatus 102.

<Third Modification>
Next, a third modification of this embodiment will be described with reference to FIGS. In the third modification, the server apparatus 102 obtains information indicating the latest update date and time, the update count, and the date and time indicating the base point of the update count for the content data, and generates status information using these pieces of information. It is.

  FIG. 14 is a flowchart illustrating an example of processing when the server apparatus 102 generates state information according to the third modification. The server apparatus 102 identifies the data management information 400 based on the request from the computer 101 in step S24 of FIG. 6 (step S60). For example, if the data identification information included in the data management information 400 is a URI, the data management information 400 having data identification information that matches the requested URI is searched. In the next step S61, the server apparatus 102 acquires the data update information 401 associated with the identified data management information 400.

  In next step S62, based on the acquired data update information 401, information indicating the latest update date and time, the number of updates, and the date and time serving as a base point for counting the number of updates is obtained for the content data. Then, state information is generated using information indicating the latest update date and time, the update count, and the update date and time of the content data. The generated state information is returned by the server apparatus 102 to the computer 101 that is the transmission source of the request.

  FIG. 15 shows an example of state information generated according to the flowchart of FIG. In the example of FIG. 15, the state information is described using XML. A tag <UPDATE> and a tag </ UPDATE> indicate that this data relates to content data update information. In addition, information indicating the latest update date and time of the corresponding content data is described in a portion between the tag <LAST_UPDATE> and the tag </ LAST_UPDATE>. Furthermore, information indicating the date and time serving as a base point of the number of updates is described in a portion between the tag <BASE> and the tag </ BASE>. Furthermore, information indicating the number of updates is described in a portion between the tag <COUNT> and the tag </ COUNT>.

  In the example of FIG. 15, the latest update date and time of the content data corresponding to this state information is 4:00 on January 5, 2007, and the base point of the update count is 0:00 on January 1, 2007. ing. Therefore, it is indicated that the content data has been updated four times between the date and time of the update count and the latest update date and time.

  As an example, it is assumed that the link information corresponding to the state information illustrated in FIG. 15 described above is registered in the computer 101 after 4 o'clock on January 5, 2007, which is the latest update date. The computer 101 can acquire this status information by the first access from the computer 101 to the server apparatus 102. In the acquired status information, information indicating the latest update date and time, the update count, and the date and time of the update count of the corresponding content data is described.

  The computer 101 divides the difference between the latest update date and time of the content data described in the status information and the date and time of the update count by the update count, and the latest update date and the date and time of the update count Find the average update interval between. Considering this average update interval as an update cycle, the date and time obtained by adding the value of this update cycle to the latest update date and time described in the status information can be used as the status information acquisition scheduled date and time 506. Therefore, the computer 101 can adaptively set the next access time to the server apparatus 102.

<Fourth Modification>
Next, a fourth modification of this embodiment will be described with reference to FIGS. In the fourth modification example, in the server apparatus 102, information indicating the latest update date and time and information indicating the update date and time performed one time before the update based on the latest update date and time are obtained for the content data. This is an example in which state information is generated using these pieces of information.

  FIG. 16 is a flowchart showing an example of processing when the server apparatus 102 generates state information according to the fourth modification. The server apparatus 102 identifies the data management information 400 based on the request from the computer 101 in step S24 of FIG. 6 (step S70). If the data identification information included in the data management information 400 is a URI, the data management information 400 having the data identification information that matches the requested URI is searched. In the next step S <b> 71, the server apparatus 102 acquires the data update information 401 associated with the identified data management information 400.

  In the next step S72, based on the acquired data update information 401, information indicating the latest update date and time for the content data and the update date and time of the update performed one time before the update by the latest update date and time are displayed. Ask for information to show. Then, status information is generated using information indicating the latest update date and time of the content data and information indicating the update date and time of the update performed once before the update based on the latest update date and time. The generated state information is returned by the server apparatus 102 to the computer 101 that is the transmission source of the request.

  FIG. 17 shows an example of state information generated according to the flowchart of FIG. In the example of FIG. 17, the state information is described using XML. A tag <UPDATE> and a tag </ UPDATE> indicate that this data relates to content data update information. In addition, information indicating the latest update date and time of the corresponding content data is described in a portion between the tag <LAST_UPDATE> and the tag </ LAST_UPDATE>. Furthermore, information indicating the update date and time of the update performed one time before the update with the latest update date and time is described in a portion between the tag <PREV_UPDATE> and the tag </ PREV_UPDATE>.

  In the example of FIG. 17, the latest update date and time of the content data corresponding to this status information is 4 o'clock on January 5, 2007, and the update one time before the update by the latest update date and time is 2007. It was shown that it took place at 3:00 on January 4th. Thereby, it can be seen that the latest update for the content was performed 25 hours after the update one time before the latest update.

  As an example, it is assumed that the link information corresponding to the state information illustrated in FIG. 17 described above is registered in the computer 101 after 4 o'clock on January 5, 2007, which is the latest update date. The computer 101 can acquire this status information by the first access from the computer 101 to the server apparatus 102. In the acquired state information, information indicating the latest update date and time of the corresponding content data and information indicating the update date and time immediately before the latest update date and time are described.

  Based on the acquired status information, the computer 101 obtains a difference between the latest update date and time and the update date and time by the update immediately before the latest update, and the date and time when this difference is added to the latest update date and time Used as the information acquisition scheduled date and time 506. As described above, the computer 101 can adaptively set the next access time to the server apparatus 102.

<Fifth Modification>
Next, a fifth modification of this embodiment will be described with reference to FIGS. In the fifth modification, the server device 102 obtains a date and time when the content data is predicted to be updated next (referred to as a predicted update date and time), information indicating the predicted update date and time, and the latest content data. It is an example which produces | generates status information using the information which shows update date.

  FIG. 18 is a flowchart illustrating an example of processing when the server apparatus 102 generates state information according to the fifth modification. The server apparatus 102 identifies the data management information 400 based on the request from the computer 101 in step S24 of FIG. 6 (step S80). If the data identification information included in the data management information 400 is a URI, the data management information 400 having the data identification information that matches the requested URI is searched. In the next step S <b> 81, the server apparatus 102 acquires the data update information 401 associated with the identified data management information 400.

  In the next step S <b> 82, the server apparatus 102 obtains a predicted update date and time based on the acquired data update information 401. As an example, the server apparatus 102 may obtain the average value of the update intervals from the acquired data update information 401, and the date and time obtained by adding the average value of the update intervals to the latest update date and time may be used as the predicted update date and time. The predicted update date and time may be obtained from the data update information 401 using linear approximation.

  Not limited to this, an update pattern of content data can be obtained from the data update information 401, and a predicted update date and time can be obtained based on the obtained update pattern. In this case, it is conceivable to obtain the predicted update date and time by comparing the obtained update pattern with a pattern prepared in advance. Further, the latest update date and time may be compared with the update date and time of the update performed one time before the update based on the latest update date and time, and the predicted update date and time may be obtained based on these differences.

  The server apparatus 102 generates state information using information indicating the obtained predicted update date and time and information indicating the latest update date and time of the content data (step S83). The generated state information is returned by the server apparatus 102 to the computer 101 that is the transmission source of the request.

  FIG. 19 shows an example of state information generated according to the flowchart of FIG. In the example of FIG. 19, the state information is described using XML. A tag <UPDATE> and a tag </ UPDATE> indicate that this data relates to content data update information. In addition, information indicating the latest update date and time of the corresponding content data is described in a portion between the tag <LAST_UPDATE> and the tag </ LAST_UPDATE>. Further, information indicating the predicted update date and time is described in a portion sandwiched between the tag <PREDICTION_DATE> and the tag </ PREDICTION_UPDATE>.

  In the example of FIG. 19, the latest update date and time of the content data corresponding to this state information is 4 o'clock on January 5, 2007, and the next update is performed at 5 o'clock on January 6, 2007. It has been shown to be predicted.

  As an example, it is assumed that the link information corresponding to the state information illustrated in FIG. 19 described above is registered in the computer 101 after 4 o'clock on January 5, 2007, which is the latest update date. The computer 101 can acquire this status information by the first access from the computer 101 to the server apparatus 102. The acquired state information describes information indicating the predicted update date and time when the corresponding content data is predicted to be updated next. Therefore, the computer 101 can appropriately set the next access time to the server apparatus 102.

<Sixth Modification>
Next, a sixth modification of this embodiment will be described. In the sixth modified example, in the server apparatus 102, as the polling interval, the first interval and the second interval longer than the first interval or one of them is determined in advance. The first interval indicates the shortest interval for polling, and the second interval indicates the longest interval for polling. In the following description, the first interval is the shortest interval and the second interval is the longest interval. The server apparatus 102 adds information indicating the shortest polling interval or the longest polling interval to the status information generated in response to the request from the computer 101 and returns it to the computer 101.

  The computer 101 obtains a polling interval based on the status information acquired from the server apparatus 102, and resets the shortest interval to the polling interval if the obtained polling interval is shorter than the shortest interval added to the status information. Similarly, if the polling interval obtained based on the state information is longer than the longest interval added to the state information, the longest interval is reset as the polling interval. The polling interval can be set even when the content data update interval is extremely short or extremely long.

  FIG. 20 is a flowchart showing an example of processing on the computer 101 side according to the sixth modification. The process illustrated in FIG. 20 corresponds to the processes in steps S24 to S29 in the flowchart of FIG. 6 described above. In the following, the processing on the computer 101 side in the sixth modification is obtained by replacing the processing in steps S24 to S29 according to the flowchart of FIG. 6 described above with the processing in steps S130 to S139 according to the flowchart of FIG. I will look down.

  Prior to the processing according to the flowchart of FIG. 20, the computer 101 performs the processing of steps S20 to S23 in the flowchart of FIG. 6 described above. First, initialization of a loop variable and the number of registered link management information 500 are acquired (step S20). Further, link management information 500 is acquired (step S22), and the status information acquisition scheduled date and time 506 in the acquired link management information 500 is compared with the processing date and time (step S23). If it is determined that the status information acquisition scheduled date and time 506 indicates the past of the processing date and time, or if the status information acquisition scheduled date and time 506 match, the process proceeds to step S130 in FIG.

  In step S130, the computer 101 refers to the link information 504 indicating the status information of the content data in the link management information 500 acquired in step S22 described above. Then, a request is made for the URI indicated by the link information 504. In response to this request, the server apparatus 102 generates state information by the processing described with reference to FIG. Then, the shortest polling interval and the longest polling interval or any one of these information is added to the generated status information and transmitted to the computer 101 which is the transmission source of the request.

  FIG. 21 shows an example of state information transmitted from the server apparatus 102 to the computer 101 in the sixth modification. A tag <UPDATE> and a tag </ UPDATE> indicate that information regarding update information of content data is described in a portion sandwiched between these tags. Information indicating the update date and time in the data update information 401 is listed in a portion between the tag <DATE> and the tag </ DATE>. A tag <POLLING> and a tag </ POLLING> are added to the tag <UPDATE> and the tag </ UPDATE>. The tag <POLLING> and the tag </ POLLING> indicate that information regarding polling is described in a portion sandwiched between these tags. Information indicating the longest polling interval is described in a portion sandwiched between the tags <MAX> and </ MAX>. Information indicating the shortest polling interval is described in a portion sandwiched between the tags <MIN> and </ MIN>.

  In the example of FIG. 21, after the content data corresponding to this state information is registered in the server apparatus 102, the first update date and time is set to 2:00 on January 3, 2007, and three times in a 25-hour cycle after registration. It shows that an update is taking place. It is also shown that the longest polling interval and the shortest polling interval are 48 hours and 10 minutes, respectively.

  Upon receiving the status information returned from the server apparatus 102, the computer 101 shifts the process to step S131. In step S131, based on the acquired status information and the information acquisition date and time 505 of the link management information 500, the content data corresponding to the status information is updated between the date and time indicated by the information acquisition date and time 505 and the processing date and time. It is determined whether it has been done.

  If it is determined that the content data has not been updated, the process proceeds to step S139, and the computer 101 sets the polling interval to a predetermined fixed value. Not limited to this, a value designated by the user for the computer 101 may be used as the polling interval. When the polling interval is set, the state information acquisition scheduled date and time is determined based on the set polling interval. Then, the process exits the series of processes shown in FIG. 20 and proceeds to step S30 in FIG.

  On the other hand, if it is determined in step S131 that the content data has been updated, the process proceeds to step S132. In step S132, the user is notified that the content data has been updated by, for example, a predetermined display on the display device 214 of the computer 101. However, the present invention is not limited to this, and the computer 101 may automatically register the database. When an update notification is made to the user, the process proceeds to step S133.

  In step S133, the received state information is analyzed in the computer 101, and a polling interval for next requesting the state information of the content data is obtained. Then, the process proceeds to step S134, and the shortest polling interval added to the received status information is compared with the polling interval obtained in step S133. As a result of the comparison, if it is determined that the polling interval obtained in step S133 is shorter than the minimum polling interval added to the status information, the process proceeds to step S136. In step S136, the polling interval is reset to the minimum polling interval added to the status information. When the polling interval is set, the process proceeds to step S138 described later.

  On the other hand, if it is determined in step S134 that the polling interval obtained in step S133 is longer than the minimum polling interval added to the status information, the process proceeds to step S135. In step S135, the longest polling interval added to the status information is compared with the polling interval obtained in step S133. As a result of the comparison, if it is determined that the polling interval obtained in step S133 is longer than the longest polling interval added to the status information, the process proceeds to step S137. In step S137, the polling interval is reset to the longest polling interval added to the status information. When the polling interval is set, the process proceeds to step S138.

  In step S138, the status information acquisition scheduled date and time, which is the date and time indicating the next timing for requesting the status information of the content data, is obtained from the polling interval obtained in the processing of steps S134 to S137. For example, the status information acquisition scheduled date and time can be obtained by adding the date and time indicated by the polling interval to the date and time when the status information was acquired last time. The obtained status information acquisition scheduled date and time is stored in the RAM 211, for example. Then, the process exits a series of processes according to the flowchart of FIG. 20, and proceeds to step S30 of FIG.

  This sixth modification can be implemented in combination with the above-described embodiment and the first to fifth modifications of the embodiment.

<Seventh Modification>
Next, a seventh modification of this embodiment will be described with reference to FIGS. This seventh modification is an example in which the time information possessed by the computer 101 and the time information possessed by the server apparatus 102 are compared, and the polling interval is adjusted according to the time information of these differences.

  If the time difference between the computer 101 side and the server device 102 side is not taken into consideration, the time when the content data is actually updated on the server device 102 side and the date and time managed by the link management information 500 on the computer 101 side Conflicts may occur between the two. For example, when the time on the server device 102 side is later than the time on the computer 101 side, even if the polling interval is controlled based on the status information, the content data is not updated on the server device 102 side when the polling is performed. This can happen.

  FIG. 22 is a flowchart illustrating an example of processing when the server apparatus 102 generates state information according to the seventh modification. When the computer 101 requests status information from the server apparatus 102 in step S24 of FIG. 6, the computer 101 adds time information indicating the time on the computer 101 side to the request. For example, information indicated by a clock of the computer 101 can be used as the time information.

  When the server apparatus 102 receives a request for status information added with time information on the computer 101 side transmitted from the computer 101, the server apparatus 102 extracts the time information on the computer 101 side from the received request. Then, the extracted time information is compared with the time information indicating the time on the server apparatus 102 side, and a difference is calculated (step S90).

  In the next step S91, the server apparatus 102 identifies the data management information 400 based on the request from the computer 101. If the data identification information included in the data management information 400 is a URI, the data management information 400 having the data identification information that matches the requested URI is searched. In the next step S92, the server apparatus 102 acquires the data update information 401 associated with the identified data management information 400.

  The server apparatus 102 generates state information from the data update information 401 acquired in step S92 and the difference time information indicating the time difference between the computer 101 side and the server apparatus 102 side calculated in step S90 ( Step S93). The generated state information is returned from the server apparatus 102 to the computer 101 that is the transmission source of the request.

  FIG. 23 shows an example of state information generated according to the flowchart of FIG. In the example of FIG. 23, the state information is described using XML. A tag <UPDATE> and a tag </ UPDATE> indicate that this data relates to content data update information. In addition, information indicating the update date and time in the data update information 401 is listed in a portion between the tag <DATE> and the tag </ DATE>. A tag <DIFFERENCE_TIME> and a tag </ DIFFERENCE_TIME> are added to the tag <UPDATE> and the tag </ UPDATE>. Difference time information is described in a portion sandwiched between the tag <DIFFERENCE_TIME> and the tag </ DIFFERENCE_TIME>.

  In the example of FIG. 23, after the content data corresponding to this state information is registered in the server apparatus 102, the first update date and time is assumed to be 0:00 on January 1, 2007, and four times in a 25-hour cycle after registration. It shows that an update is taking place. Further, it is shown that there is a time difference of 9 hours between the time on the computer 101 side and the time on the server device 102 side. The computer 101 that has received the status information can adjust the status information acquisition scheduled date and time obtained by analyzing the status information based on the difference time information.

  In the seventh modified example, the time between the computer 101 and the server apparatus 102 is adjusted by transmitting the difference time information when returning the status information from the server apparatus 102 in response to the request from the computer 101. Like to do. This is not limited to this example. For example, the computer 101 may obtain difference time information for each server apparatus 102 indicated by the link information 504 by using NTP (Network Time Protocol).

  Further, this seventh modification can be implemented in combination with the above-described embodiment and the first to sixth modifications of the embodiment.

<Eighth Modification>
Next, an eighth modification of the present embodiment will be described with reference to FIGS. The above-described embodiment and the first to seventh modifications of the embodiment are based on the assumption that the server apparatus 102 always manages the same information and transmits the same information to a plurality of clients (computers 101) that perform polling. It is said.

  On the other hand, in the eighth modification, it is assumed that a plurality of clients calculate the polling interval and the next polling time based on the state information transmitted from the server apparatus 102. Then, according to the calculated polling interval and time, the concentration of access to the server apparatus 102 that occurs when the plurality of clients perform polling at the same time is avoided.

  FIG. 25 shows an example of the management structure of the update history according to the eighth modification. The system according to the eighth modification has data management information 600 for identifying each piece of content data managed by the server apparatus 102, and data update information 610 associated with the data management information 600 by ID information. The data management information 600 includes a management ID 601, a name, link information as identification information for identifying content data, link information indicating status information of the content data, information acquisition date and time, and status information acquisition scheduled date and time.

  On the other hand, in the data update information 610, an ID 611, an update date and time 612 of content data corresponding to the ID 611, and a polling count 613 are associated. The ID 611 corresponds to the management ID 601 in the data management information 600. Data update information 610 is added each time the content data is updated. The polling count 613 indicates the number of accesses from the client for polling since the content data was updated. That is, the polling count 613 is the number of status information requests made from the client to the server apparatus 102. When there is an access for polling from the computers 101, 101,..., The server apparatus 102 increments the polling count 613 by 1 for the data update information 610 corresponding to the latest content data that has been updated.

  Although illustration is omitted, in addition to identification information for identifying content data in the data management information 600, the content data itself may be included, or information such as a path to the content data may be included. It can also be included. Generation and deletion of the data management information 600 and the data update information 610 are performed in the server apparatus 102.

  FIG. 26 is a flowchart schematically showing acquisition processing of an example of data state information according to the eighth modification of the embodiment of the present invention. In step S150, when a predetermined date and time is reached in the user computer 101, a request is transmitted to the server apparatus 102 having content data specified by link information registered in advance by polling. Thereby, status information indicating the status of the content data is requested.

  Upon receiving this request, the server apparatus 102 adds 1 to the polling count 613 of the data update information 610 corresponding to the requested latest content data (step S151). Then, in the next step S152, the status information of the content data requested is returned to the computer 101 that made the request. This state information includes the number of polls 613 as described with reference to FIG.

  The computer 101 determines whether the corresponding content data has been updated based on the received status information (step S153). If it is determined that the content data has been updated, the process proceeds to step S154. Also, if it is the first request for the status information of the content data, the process proceeds to step S154.

  In step S154, the user is notified that the content data has been updated by, for example, a predetermined display on the display device 214 of the computer 101. However, the present invention is not limited to this, and the computer 101 may automatically register the database. When an update notification is made to the user, the process proceeds to step S155.

  In step S155, the received state information is analyzed in the computer 101, and a polling interval for next requesting the state information of the content data is obtained. In the next step S156, the polling interval for the next polling is adjusted based on the polling interval obtained in step S155 and the number of polls included in the status information returned from the server apparatus 102 in step S152. Details of this next polling interval adjustment process will be described later.

  When the next polling interval is adjusted in step S156, the process proceeds to step S157. In step S157, a scheduled status information acquisition date is obtained from the adjusted polling interval, which is the date and time indicating the timing of the next request for the content data.

  On the other hand, if it is determined in step S153 described above that the content data has not been updated, the process proceeds to step S158. In step S158, the polling interval is set to a predetermined fixed value in the computer 101. Not limited to this, a value designated by the user for the computer 101 may be used as the polling interval. When the polling interval is set, the date and time when status information is scheduled to be acquired next time is obtained based on the set polling interval. The status information acquisition scheduled date and time is determined by the date and time when the status information thus obtained is scheduled to be acquired next time.

  When the state information acquisition scheduled date / time determined in step S157 or step S158 is reached as described above, the computer 101 performs the processing from step S150 again to update the status information acquisition scheduled date / time.

  FIG. 27 is a flowchart illustrating an example of the polling interval adjustment process performed in the computer 101 (client) described in step S156 described above. First, in step S170, the predicted content update interval T is acquired. The predicted content update interval T is the polling interval obtained in step S155 described above.

  In the next step S171, the predicted polling count C predicted during the predicted content update interval T is obtained. The predicted polling count C holds, for example, the update history of content data confirmed in the past in the computer 101 and the polling count performed within each update interval, and the average of the polling count within each update interval. It can be obtained as a value. Not limited to this, the predicted polling count C may be the polling count from the previous update until the latest update of the content data is performed.

  Further, in the next step S172, the number N of polling times for the latest content data, that is, the number of clients that have polled the latest content data by the computer 101 is acquired. This can be acquired based on the polling count 613 included in the state information returned from the server apparatus 102 in step S152.

In the next step S173, assuming that there is an access of the predicted polling count C times in the predicted content update interval T described above, the time interval when polling is equally performed in the predicted content update interval T according to the following equation (1) Get U.
Time interval U = predicted content update interval T / predicted polling count C (1)

In the next step S174, it is determined whether or not the polling count N for the latest content data exceeds the predicted polling count C. If it is determined that it has not exceeded, the process proceeds to step S175, and the polling interval adjustment amount A is calculated from the number N of polling times and the time interval U obtained in step S173 by the following equation (2). Ask for. For example, the adjustment amount A is added to the polling interval obtained in step S155.
Adjustment amount A = Time interval U × Number of polling times N (2)

  On the other hand, if it is determined in step S174 that the polling count N has already exceeded the predicted polling count C, the process proceeds to step S176. In step S176, the polling count N is divided by the predicted polling count C, and the remainder R is replaced with the polling count N. In other words, the remainder R is used as the new polling count N. Then, the process proceeds to step S175, and the adjustment amount A is calculated by equation (2) using the polling count N replaced with the remainder R.

  In this way, the adjustment amount A of the polling interval for each computer 101 is obtained. In each of the computers 101, 101,..., The adjustment amount A is obtained based on the polling count N of the computer 101 for the latest content data. Therefore, for example, even if the predicted content update interval T is the same in each of the computers 101, 101,..., The actual polling time is uniformly distributed within the predicted content update interval T, and Concentration of access can be suppressed.

  In the above description, the adjustment interval A is obtained using the predicted content update interval T as it is, but this is not limited to this example. For example, a part of the polling interval obtained in step S155 can be used as the predicted content update interval T.

  FIG. 28 shows an example of the state information transmitted from the server apparatus 102 to the computer 101 (client) in the eighth modification. A tag <UPDATE> and a tag </ UPDATE> indicate that information regarding update information of content data is described in a portion sandwiched between these tags. Information indicating the update date and time 612 in the data update information 610 is described in a portion between the tag <DATE ACCESS = xxxx> and the tag </ DATE>. Note that “xxxx” in the tag <DATE ACCESS = xxxx> indicates the number of polls 613. That is, “ACCESS = xxxx” that is an attribute of the tag <DATE ACCESS = xxxx> is the number of requests (polling count 613) from the computers 101, 101,... Between the update indicated by the tag. ).

  In the example of FIG. 28, it can be seen that data is updated four times in a 25-hour cycle after registration. Further, the requests from the computers 101, 101,... Are 1200 times before the first update, 1228 times between the first and second updates, and 1312 times between the second and third updates. It can be seen that there were 1280 times between the third and fourth updates. Further, it can be seen that the polling from a certain computer 101 is the 625th request after the fourth update.

  With reference to the example of the status information in FIG. 28, a case is considered in which the content data corresponding to the status information is registered in the computer 101 after 4 o'clock on January 05, 2007. In this case, the state information can be acquired by the first access to the server apparatus 102 based on the determination in step S153 of FIG. Therefore, the computer 101 can appropriately set the next access time to the server apparatus 102.

  Moreover, it can be predicted from the polling results regarding the past four updates that there is an average of 1255 polls between the update of the content data. Therefore, it can be calculated from the formula (1) that it is only necessary to disperse polling every approximately 71 seconds (25 hours / 1255 times). Therefore, the adjustment amount A can be calculated as 12 hours 19 minutes 35 seconds from the equation (3) (71 seconds × 625 times). Therefore, the next scheduled polling time from the computer 101 is 17:19:35 on January 06, 2007.

  Note that the processing described with reference to FIG. 6 can be applied to the processing on the computer 101 side in the eighth modification. In this case, a polling interval adjustment process in step S156 in the flowchart in FIG. 26 is performed between step S14 and step S15 in FIG.

  The eighth modification can be implemented in combination with the seventh modification described above.

<Ninth Modification>
Next, a ninth modification of the present embodiment will be described with reference to FIG. The ninth modification is an example in which the polling interval by the computer 101 is determined from the server device 102 side.

  FIG. 29 is a flowchart showing an example of processing when the server apparatus 102 generates state information according to the ninth modification. In step S180, the server apparatus 102 identifies the data management information 600 based on the request from the computer 101 in step S24 of FIG. 6 described above. In the next step S181, 1 is added to the number of polls 613 for the latest requested content data in the data update information 610 associated with the identified data management information 600.

  When the polling count 613 is updated in step S181, the process proceeds to step S182, and the update date and time 612 is acquired from the data update information 610 associated with the data management information 600 identified in step S180. In the next step S183, the update interval of the content data is predicted from the acquired update date 612 using linear approximation or the like.

  As a method for obtaining the update interval, in addition to a method using linear approximation, a method for obtaining an update pattern from the update date and time 612 and predicting an update from a matching pattern can be considered. Further, the method for obtaining the update interval may be a method of simply comparing only the last update date and time and the current update date and time.

  In the next step S184, the adjustment amount A is calculated based on the update interval obtained in step S183 and the polling count 613 updated in step S181. The calculation method of the adjustment amount A here is the same as the method described with reference to FIG. For example, the update interval obtained in step S183 is set as the predicted content update interval T, and the expected polling count C is obtained based on the polling count 613 corresponding to the update date 612 other than the latest. Also, the polling count 613 corresponding to the latest update date and time 612 is set as the polling count N. Based on these, the above-described equation (2) is calculated to calculate the adjustment amount A.

  When the adjustment amount A is calculated, the process proceeds to step S185, and the predicted update date and time is obtained based on the update interval obtained in step S183 and the adjustment amount A obtained in step S184. For example, the date and time when the adjustment amount A is added to the latest update date and time 612 in the data update information 610 is set as the predicted update date and time. The server apparatus 102 generates status information based on the calculated predicted update date and time and the latest update date and time 612. This state information can have a structure as described with reference to FIG. The generated state information is returned from the server apparatus 102 to the computer 101 that is the transmission source of the request.

  The computer 101 can acquire this status information by the first access from the computer 101 to the server apparatus 102. The acquired status information describes information indicating the predicted update date and time when the corresponding content data is predicted to be updated next. Therefore, the computer 101 can appropriately set the next access time to the server apparatus 102.

  As described above, according to the ninth modification, the polling interval of the computer 101 can be determined based on the adjustment amount A obtained on the server apparatus 102 side.

  According to the ninth modification, the predicted update date / time uses the adjustment amount A obtained based on the remainder R when the polling count N added in response to the request from the computer 101 is divided by the predicted polling count C. Generated. Therefore, for example, even if the predicted content update interval T is the same in each of the computers 101, 101,..., The actual polling time is uniformly distributed within the predicted content update interval T, and Concentration of access can be suppressed.

  Note that the ninth modification can be implemented in combination with the seventh modification described above.

  In the above-described embodiment and each modified example, when the computer 101 has a plurality of link management information 500, a priority order is set for each link management information 500 for the process of acquiring the state information. be able to. More specifically, prior to performing the processing of step S20 in FIG. 6 described above, as illustrated in step S95 of FIG. 24, the link management information 500 is sorted in descending order by the information acquisition date and time 505, that is, the current Set the order so that it becomes the past order. The processes in and after step S21 in FIG. 6 are sequentially performed on the plurality of link management information 500 in the order set in step S95.

  Further, in the above description, the present invention is described as corresponding to the RSS feed and acquiring the update information of the RSS feed, but this is not limited to this example. That is, the present invention is also suitable for use when acquiring update information of other data distributed on the Internet.

  As a specific example, the present invention can be applied when acquiring update information of a Web site on the Internet. In this case, data of various levels of the website, such as the website itself, each web page constituting the website, image data and text data displayed in the web page, and the like can be acquired.

<Other embodiments>
In the above-described embodiment and each modified example of the embodiment, the server apparatus 102 and the computer 101 have been described as being configured from a single device, but this is not limited to this example. For example, functions equivalent to those of the computer 101 and the server apparatus 102 according to the present invention may be realized by a system composed of a plurality of devices.

  Furthermore, in order to implement the above-described embodiments with a computer, the computer program itself supplied to the computer also implements the present invention. That is, the computer program itself for realizing the functions of the above-described embodiments is also one aspect of the present invention.

  The computer program for realizing the above-described embodiment may be in any form as long as it can be read by a computer. For example, it can be composed of object code, a program executed by an interpreter, script data supplied to the OS, but is not limited thereto.

  A computer program for realizing the above-described embodiment is supplied to a computer via a storage medium or wired / wireless communication. Examples of the storage medium for supplying the program include a magnetic storage medium such as a flexible disk, a hard disk, and a magnetic tape, an optical / magneto-optical storage medium such as an MO, CD, and DVD, and a nonvolatile semiconductor memory.

  As a computer program supply method using wired / wireless communication, there is a method of using a server on a computer network. In this case, a data file (program file) that can be a computer program forming the present invention is stored in the server. The program file may be an executable format or a source code.

  Then, the program file is supplied by downloading to a client computer that has accessed the server. In this case, the program file can be divided into a plurality of segment files, and the segment files can be distributed and arranged on different servers.

  That is, a server apparatus that provides a client computer with a program file for realizing each of the above-described embodiments is also one aspect of the present invention.

  In addition, a storage medium that encrypts and stores a computer program for realizing each of the above-described embodiments is distributed, and key information for decryption is supplied to a user who satisfies a predetermined condition, and the computer has the computer. May be allowed to install. The key information can be supplied by being downloaded from a homepage via the Internet, for example.

  In addition, the computer program for realizing each of the above-described embodiments may use an OS function already running on the computer.

  Further, a part of the computer program for realizing the above-described embodiment may be configured by firmware such as an expansion board attached to the computer, or may be executed by a CPU provided in the expansion board. Good.

It is a basic diagram which shows the structure of an example of the system applicable to this invention. It is a block diagram which shows the structure of an example of the user side computer. It is a flowchart which shows roughly the acquisition process of an example of the data status information by embodiment. It is a basic diagram which shows the management structure of an example of the update log | history in a server apparatus by embodiment. It is a basic diagram which shows the link management information of an example which the computer side has by embodiment. It is a flowchart which shows a process of an example of the computer side which acquires state information by embodiment. It is a flowchart which shows an example process performed by the server apparatus side corresponding to the process by the computer side by embodiment. It is a basic diagram which shows roughly the example status information transmitted to the computer from a server apparatus by embodiment. It is a basic diagram which shows the structure of an example of the management information which the computer side has in order to manage link information by the 1st modification of embodiment. It is a flowchart which shows a process of an example of the computer side which acquires state information by the 1st modification. It is a flowchart which shows the process of an example performed by the server apparatus side corresponding to the process by the side of a computer by the 1st modification. It is a flowchart which shows an example process when a server apparatus produces | generates status information by the 2nd modification of embodiment. It is a basic diagram which shows the example status information produced | generated by the 2nd modification. It is a flowchart which shows an example process when a server apparatus produces | generates status information by the 3rd modification of embodiment. It is a basic diagram which shows the example status information produced | generated by the 3rd modification. It is a flowchart which shows an example process when a server apparatus produces | generates status information by the 4th modification of embodiment. It is a basic diagram which shows the example status information produced | generated by the 4th modification. It is a flowchart which shows an example process when a server apparatus produces | generates status information by the 5th modification of embodiment. It is a basic diagram which shows the example status information produced | generated by the 5th modification. It is a flowchart which shows the process of an example of the computer side by the 6th modification of embodiment. It is a basic diagram which shows the structure of an example of the status information transmitted with respect to a computer from a server apparatus in a 6th modification. It is a flowchart which shows an example of a process at the time of a server apparatus producing | generating status information by the 7th modification of embodiment. It is a basic diagram which shows the example status information produced | generated by the 7th modification. It is a flowchart for demonstrating setting a priority for every link management information with respect to the process which acquires state information. It is a basic diagram which shows the management structure of an example of the update history which concerns on the 8th modification of embodiment of this invention. It is a flowchart which shows roughly the acquisition process of an example of the data status information by the 8th modification of embodiment of this invention. It is a flowchart of an example which shows the adjustment process of the polling interval performed in a client. In the 8th modification of embodiment of this invention, it is a basic diagram which shows the structure of an example of the status information transmitted with respect to a client from a server apparatus. It is a flowchart which shows an example process when a server apparatus produces | generates status information by the 9th modification of embodiment of this invention.

Explanation of symbols

100 Internet 101 Computer 102 Server 400 Data management information 401 Data update information 500 Link management information 504 Link information 505 indicating status information of content data Information acquisition date 506 Status information acquisition scheduled date

Claims (24)

A communication system in which a server device and a client device are communicably connected via a network,
The server device is
Content data management means for managing an update history of content data accessed by the client device via the network;
Generating means for generating status information indicating an update status of the content data based on the update history managed by the content data management means;
The client device is
Requesting means for requesting the status information to the server device;
A determination unit that determines a timing at which the request unit should make the request next based on the state information acquired by the request of the request unit;
Control means for causing the request means to make the request at the timing determined by the determination means ,
The generation unit of the server device generates the update history as the state information in response to the request,
The determination unit of the client device determines the timing based on an update date and time interval included in the update history,
The request unit of the client device performs the request by adding an information acquisition date and time indicating the date and time when the status information was acquired last time,
The generation unit of the server device generates, as the state information, an update history indicating an update date and time after the information acquisition date and time among the update history,
The generation unit of the server device generates the state information in response to the request, and sets a first interval and a second interval longer than the first interval or any one of them, Attached to the status information,
The determination unit of the client device is configured such that an interval between the timing at which the request is performed by the request unit and the timing at which the request is to be performed next determined based on the state information is shorter than the first interval. Determines again the timing at which the next request should be made based on the result of adding the first interval to the time indicated by the timing at which the request is made by the request means, When the interval is longer than the second interval, the timing at which the next request is to be made is determined again based on the result of adding the second interval to the time indicated by the timing at which the request is made by the request means. A communication system characterized by the above. In response to the request, the generation unit of the server device obtains an average value of the update interval of the content data based on the update history and obtains the latest update date and time of the content data. An average value and the latest update date and time are generated as the state information,
The communication system according to claim 1, wherein the determination unit of the client device determines the timing based on a result of adding an average value of the update intervals to the latest update date and time. In response to the request, the generation means of the server device is a base date and time for counting the number of updates of the content data based on the update history, and an update count at which the content data is updated from the base date and time. And obtaining the latest update date and time of the content data, generating the base date and time, the number of updates and the latest update date and time as the status information,
The determination unit of the client device obtains an average value of the update interval from the base date and time, the number of updates, and the latest update date and time, and results of adding the average value of the update interval to the latest update date and time The communication system according to claim 1, wherein the timing is determined based on: In response to the request, the generation means of the server device updates the content data with the latest update date and time and the update performed once before the update with the latest update date and time. A date and time, and the obtained latest update date and time and the update date and time of the update performed once before are generated as the state information,
The determining unit of the client device obtains a difference between the latest update date and time and an update date and time of the update performed once before, and determines the timing based on a result of adding the difference to the latest update date and time. The communication system according to claim 1. In response to the request, the generation unit of the server device obtains a predicted update date and time predicted to update the content data next based on the update history, and generates the calculated predicted update date and time as the state information. And
The communication system according to claim 1, wherein the determination unit of the client device determines the predicted update date and time as the timing. The content data management means of the server device associates the update history with the update date and time when the content data was updated and the number of requests made until the next update from the update. Manage
The generation unit of the server device generates the update history including the number of requests corresponding to the request as the state information in response to the request,
The client device is
An adjustment means for adjusting the timing determined by the determination means based on the number of requests included in the state information;
The communication system according to claim 1, wherein the control unit of the client device causes the request unit to make the request at a timing adjusted by the adjustment unit. The adjustment unit of the client device predicts a time interval of the request from the update date and time and the number of requests included in the update history, and determines the predicted time interval and the number of requests corresponding to the request. The communication system according to claim 6 , wherein the adjustment is performed based on the communication. The content data management means of the server device associates the update history with the update date and time when the content data was updated and the number of requests made until the next update from the update. Manage
In response to the request, the generation unit of the server device predicts an update interval of the content data based on the update history including the number of requests from the update performed immediately before the request to the request, Obtaining the predicted update date and time of the content data based on the update interval and the number of requests, generating the calculated predicted update date and time as the status information,
The communication system according to claim 1, wherein the determination unit of the client device determines the predicted update date and time as the timing. The generation means of the server device includes:
The time interval of the request is predicted from the update date and time and the number of requests included in the update history, and the predicted time interval and the number of requests from update to request performed immediately before the request The communication system according to claim 8 , wherein the predicted update date and time is obtained based on: The request unit of the client device performs the request by adding time information indicating a time on the client device side,
The generation unit of the server device generates the state information in response to the request, and obtains time information of a difference between time information indicating time on the client device side and time information indicating time on the server device side. Added to the status information,
The control means of the client device uses the time information of the difference added to the status information to adjust the timing for making the next request determined based on the status information. The communication system according to any one of claims 1 to 9 . The content data is metadata describing an outline of resource data accessed by the client device via the network,
Said server device, by the content data management means, one of claims 1 to 10, characterized in that updating of the update history corresponding to the content data and the content data in accordance with the updating of the resource data The communication system according to claim 1. A communication method of a communication system in which a client device and a server device having content data management means for managing an update history of content data accessed by the client device via a network are connected via the network. There,
A request sending step in which the client device sends a request for status information indicating a status of updating content data managed by the content data management means to the server device;
A generating step in which the server device generates status information indicating a status of updating content data based on the update history managed by the content data management unit in response to the request from the client device;
A transmission step in which the server device transmits the state information generated in the generation step to the client device via the network in response to the request from the client device;
Determination that the client device determines the timing for transmitting the status information request in the request transmission step, based on the status information transmitted from the server device in response to the request transmitted in the request transmission step. and a step,
The server device generates the update history as the state information in response to the request,
The client device determines the timing based on an update date and time interval included in the update history,
The client device performs the request by adding an information acquisition date and time indicating the date and time when the status information was acquired last time,
The server device generates, as the state information, an update history indicating an update date and time after the information acquisition date and time among the update history,
The server device generates the state information in response to the request, and sets the first interval and / or the second interval longer than the first interval and adds the state information to the state information. And
When the interval between the timing at which the request is made by the requesting unit and the timing at which the request is to be performed next determined based on the state information is shorter than the first interval, the client device 1 is determined again based on the result obtained by adding the interval of 1 to the time indicated by the timing at which the request is made by the requesting means, and the interval from the timing at which the request is to be made is determined again. When the interval is longer than 2, the second timing is added to the time indicated by the timing at which the request is made by the request means, and the timing at which the next request is to be made is determined again. Communication method. A client device that accesses a server device that manages the update history of content data via a network,
Request means for requesting the server device for status information indicating a status of updating content data managed by the server device;
Determining means for obtaining the status information generated by the server device in response to a request by the request means, and determining when the request means should make the request next;
Control means for causing the request means to make the request at the timing determined by the determination means ,
The determining means includes
In response to the request, the server device determines the timing based on an update date and time interval included in the update history generated as the status information,
The request means performs the request by adding an information acquisition date and time indicating the date and time when the status information was acquired last time,
The determining means includes
Using an update history that is generated as the status information in the server device in response to the request and that indicates an update date and time later than the information acquisition date and time of the update history based on the information acquisition date and time transmitted with the request Determine the timing,
The determining means includes
In response to the request, the state information generated by the server device, a first interval for the request added to the state information, and a second interval longer than the first interval, or any of these Based on either
When the interval between the timing at which the request is made by the request means and the timing at which the request is to be performed next determined based on the state information is shorter than the first interval, the first interval is set as the first interval. Based on the result added to the time indicated by the timing at which the request is made by the requesting means, the timing at which the next request is to be made is determined again, and the interval from the timing at which the next request is made is longer than the second interval. In this case, the client apparatus determines again the timing at which the next request should be made based on the result of adding the second interval to the time indicated by the timing at which the request is made by the request means . The determining means includes
Using the average value of the update intervals of the content data and the latest update date and time of the content data, which are generated as the status information in the server device in response to the request, the update interval The client apparatus according to claim 13 , wherein the timing is determined based on a result obtained by adding average values. The determining means includes
The base date and time for counting the number of updates of the content data generated as the status information in the server device in response to the request, the number of times the content data has been updated from the base date and time, Using the latest update date and time of the content data, an average value of the update interval of the content data is obtained from the base date and time, the number of updates, and the latest update date and time, and the average value of the update interval is calculated The client device according to claim 13 , wherein the timing is determined based on a result added to the update date and time. The determining means includes
Using the latest update date and time of the content data generated as the status information in the server device in response to the request, and the update date and time of the update performed once before the update by the latest update date and time And calculating the difference between the latest update date and time and the update date and time of the update performed once before, and determining the timing based on a result of adding the difference to the latest update date and time. Item 14. The client device according to Item 13 . The determining means includes
The client apparatus according to claim 13 , wherein a predicted update date and time generated as the state information from the server apparatus in response to the request and predicted to update the content data next is determined as the timing. . The timing determined by the determining means is generated as the status information in the server device in response to the request, the update date and time when the content data is updated, and the next update is performed from the update An update history that is associated with the number of requests that have been requested so far, and further adjusts based on the number of requests,
The client device according to claim 13 , wherein the control unit causes the request unit to make the request at a timing when the timing is adjusted by the adjustment unit. The adjusting means includes
The request time for predicting the time interval of the request from the update date and time and the number of requests included in the update history, and causing the server device to generate the status information. 19. The client apparatus according to claim 18 , wherein the adjustment is performed based on the number of requests from the update immediately before the request made by the means to the request. The request means performs the request by adding time information indicating the current time,
Using time information indicating the difference between the time information indicating the current time and the time information indicating the time on the server device side, which is added to the state information generated by the server device in response to the request. the client device according to any one of claims 13 to claim 19, characterized in that to adjust the timing for the request to the next which is determined based on the state information. The content data is metadata describing an outline of resource data accessed via the network,
The update of the content data in response to the resource data updated by the server device is performed, according to claim 13 in which update history of the content data has been made in response to the update of the resource data is characterized in that it is managed The client device according to any one of claims 20 to 20 . A method for controlling a client device that accesses content data managed together with an update history to a server device via a network,
A requesting step of requesting the server device for status information indicating a status of updating content data managed by the server device;
A determination step of determining when the request step should make the request next based on the status information generated by the server device in response to the request by the request step;
A control step for causing the requesting step to perform the request at the timing determined by the determining step ,
In the determination step,
In response to the request, the server device determines the timing based on an update date and time interval included in the update history generated as the status information,
In the request step, the request is made by adding an information acquisition date and time indicating the date and time when the status information was acquired last time,
In the determination step,
Using an update history that is generated as the status information in the server device in response to the request and that indicates an update date and time later than the information acquisition date and time of the update history based on the information acquisition date and time transmitted with the request Determine the timing,
In the determination step,
In response to the request, the state information generated by the server device, a first interval for the request added to the state information, and a second interval longer than the first interval, or any of these Based on either
When the interval between the timing at which the request is made in the requesting step and the timing at which the next request should be made determined based on the state information is shorter than the first interval, the first interval is set as the first interval. Based on the result added to the time indicated by the timing at which the request is made in the request step, the timing at which the next request is made is determined again, and the interval from the timing at which the next request is made is longer than the second interval. In this case, the control method is characterized in that , based on the result of adding the second interval to the time indicated by the timing at which the request is made in the request step, the timing at which the next request should be made is determined again . The program for functioning a computer as a server apparatus in any one of Claims 1 thru | or 11 . A program for causing a computer to function as the client device according to any one of claims 1 to 11 and claims 13 to 21 .

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