JP2010073013A - Data communication system and server device, and method and program for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that when a client terminal requests a server device to reproduce an image on the Web, if a cached image is in the client terminal, the cached image is reproduced, but the cached image may not match the image on the Web. <P>SOLUTION: A checksum of the cached image in the client terminal and a checksum of the image on the Web are compared with each other, and it is confirmed whether there is no change in the cached image. If there is no change in the cached image, the cached image is reproduced. If there is any change in the cached image, an image on the Web is obtained again. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for an information processing apparatus to receive and reproduce data via a network.

  Conventionally, when a client terminal acquires data from a server via a network, the cache data is generated once the data is acquired, and the cache data is used without acquiring the data from the server after the second time. There is something. Further, the creation date / time of cache data is compared with the creation date / time of data on the server, and when the cache data is not the latest data, there is one that re-acquires data from the server (for example, Patent Document 1). reference.).

When the personal computer (PC) is displaying a list of thumbnail images on the screen, if the pointer is hovered over one of the thumbnail images, a thumbnail image larger in size than the thumbnail image displayed in the list is displayed in a pop-up manner. There is something to do. Here, the thumbnail image of the pop-up display is cached and used for the next pop-up display. If there is no cache, the thumbnail image of the pop-up display is generated from the original image corresponding to the thumbnail image of the list display (for example, patent Reference 2).
JP 2006-040132 A JP 09-212397 A

  However, when the client terminal cache data is used instead of the server data as in Patent Document 1, if the client terminal data is changed, the data that does not match the server data is used. And there is a problem of causing confusion to the user. Data of the client terminal may be rewritten by editing processing by a user operation.

  In order to solve the above problems, the present invention provides a data communication system in which a server device and a client terminal can communicate via a network, wherein the server device downloads data to the client terminal, and the download Receiving a request for downloading data from the client terminal, generating means for generating a checksum of the generated data, storage means for storing the data in association with the generated checksum, and receiving the request from the client terminal Transmitting means for transmitting a checksum corresponding to the received data to the client terminal, wherein the client terminal stores storage data downloaded from the server device, and a checksum transmitted from the server device; , Stored in the storage means A comparison means for comparing the checksums of the received data, and if the checksums match as a result of the comparison, the data stored in the storage means is reproduced, and if the checksums do not match, the server And reproduction control means for controlling to download and reproduce new data from the apparatus.

  According to the present invention, when the client terminal requests the data of the server device, the client terminal is consistent with the data of the server device when the cache data of the client terminal is used instead of the data of the server device. Data can be used accurately.

(First embodiment)
Preferred embodiments of the present invention will be described below with reference to the drawings. However, the constituent elements described in this embodiment are merely examples, and are not intended to limit the scope of the present invention only to them.

  FIG. 1 is a diagram showing an example of the overall configuration of a data communication system 100 according to the present invention. An image management server apparatus 101 and a client terminal 102 are connected via a network 103. The image management server apparatus 101 is a Web server that stores multimedia information such as HTML documents, XML documents, and images, and transmits the information via a network 103 in response to a request from the client terminal 102. For example, the image management server apparatus 101 classifies a plurality of pieces of image data according to the attribute information (photographing date / time, tag, photographer, comment, etc.) and stores them in association with each folder. The client terminal 102 is a communication device such as a personal computer (PC) or a mobile phone. A web browser is installed on the client terminal 102, and a request can be made to the image management server device 101 via the network 103.

  In this embodiment, when the client terminal 102 makes a request to the image management server apparatus 101, a folder icon 303 managed by the image management server apparatus 101 is displayed on the Web browser display screen of the client terminal 102 as shown in FIG. Displayed above. When the cursor 301 is moved over the folder icon 303 in response to the user's operation of the pointing device 205, a reduction corresponding to the image data stored in the folder is displayed in the pop-up window 302 as shown in FIG. Display an image. In addition to the reduced image, a summary, a file name, and the like may be displayed. If the image data is a moving image, the moving image is reproduced in the pop-up window 302.

  In the present embodiment, a Web browser will be described as an example. However, data provided from the image management server apparatus 101 can be used, and can be similarly realized by other application program software having a function of displaying an image. .

  Next, information processing apparatuses that constitute the image management server apparatus 101 and the client terminal 102 will be described with reference to the block in FIG. The information processing apparatus is realized by a computer apparatus. As illustrated in FIG. 2, the information processing apparatus includes a CRT display 201, a VRAM 202, a BMU 203, a keyboard 204, a PD 205, a CPU 206, a ROM 207, a RAM 208, an HDD 209, an FDD 210, and a network I / F 211. A CRT (Cathode Ray Tube) display 201 displays, for example, a document being edited, a figure, an image, and other editing information, icons, messages, menus, and other user interface information. An image to be displayed on the CRT display 201 is drawn on the VRAM 202. The image data generated in the VRAM 202 is transferred to the CRT display 201 according to a predetermined rule, whereby an image is displayed on the CRT display 201. The BMU (bit move unit) 203 is, for example, data transfer between memories (for example, between the VRAM 202 and another memory) or data between the memory and each I / O device (for example, the network I / F 211). Control the transfer. The keyboard 204 has various keys for inputting documents and the like. A PD (pointing device) 205 is used, for example, to instruct icons, menus, and other contents displayed on the CRT display 201. The CPU 206 controls each device based on a control program stored in the ROM 207, HDD 209, or flexible disk. The ROM 207 stores various control programs and data.

  The RAM 208 has a work area for the CPU 206, a data save area for error processing, a control program load area, and the like. The HDD 209 stores each control program and content executed in the information processing apparatus. For example, the HDD 209 of the client terminal 102 stores an operating system (OS), a Web browser, an image file, electronic album data, an electronic album editing program, and the like. The FDD 210 controls access to a flexible disk represented by floppy (registered trademark) or the like. A network I / F 211 communicates with other information processing apparatuses, printers, and the like via a network. The CPU bus 212 includes an address bus, a data bus, and a control bus. The provision of the control program to the CPU 206 can be performed from the ROM 207, the HDD 209, and the FDD 210, or can be performed from another information processing apparatus or the like via the network via the network I / F 211.

  The procedure in which the client terminal 102 displays the image data stored in the image management server apparatus 101 on the screen will be described with reference to the flowchart shown in FIG.

  The client terminal 102 has already started the Web browser, the login authentication of the user of the client terminal 102 to the image management server apparatus 101 has been normally completed, and the image management server apparatus 101 is accessed via the network 103. Suppose that it is in a state. The client terminal 102 displays a list screen 300 of folders managed by the image management server apparatus 101 as shown in FIG. 3A on the screen of the Web browser according to the HTML document acquired from the image management server apparatus 101. Control.

  In step S400, the client terminal 102 acquires, from the image management server apparatus 101, a data ID for uniquely identifying image data to be displayed in a pop-up display by a user's selection operation. The data ID may be a file path to image data on the image management server apparatus 101.

  Specifically, in response to the user operating the pointing device, the pointer moves over the folder icon 303. Thereby, the data ID of the image data representing the folder corresponding to the icon 303 under the pointer is acquired. The HTML document acquired from the image management server apparatus 101 describes the data ID of the representative image of each folder, and the client terminal 102 reads the data ID of the representative image of the designated folder from the HTML document. Further, for example, the representative image data is the latest image data registered last in the folder.

  In step S401, the client terminal 102 confirms cache information management to be described later, and determines whether image data corresponding to the data ID acquired in step S400 is cached.

  If it is determined in step S401 that there is no cache of image data corresponding to the data ID acquired in step S400, the client terminal 102 downloads image data corresponding to the data ID from the image management server apparatus 101 in step S402. To do. Then, it is stored in the hard disk 209 of the client terminal 102. At this time, a new file path different from the file path stored in the cache information management table 500 is generated, and the newly downloaded image data is stored based on the new file path. Then, the corresponding record in the cache information management table 500 is updated with a new file path. Thereby, when the user has changed the existing image data, it can be prevented from being overwritten by the newly downloaded image data, and the new image data can be used as a cache image. In step S403, the client terminal 102 generates a checksum of the image data downloaded in step S402.

  In step S404, the client terminal 102 stores the data ID acquired in step S400, the file path to the image data downloaded in step S402 on the client terminal 102, and the checksum generated in step S403 in association with each other. . These are stored in a cache information management table 500 as shown in FIG. That is, when the image data having the data ID specified in step S400 is cached in the hard disk 209 of the client terminal 102, the corresponding record is stored in the cache information management table 500.

  In the example of the cache information management table 500 in FIG. 5, for each image data, a record in which the data ID 501, the checksum value 502, and the file path 503 to the image data cached in the client terminal 102 are associated is stored.

  In step S405, the client terminal 102 controls to display the image data downloaded in step S402 on a pop-up screen.

  If it is determined in step S401 that there is a cache of image data corresponding to the data ID acquired in step S400, the client terminal 102 reads the image data cached in the hard disk 209 based on the file path 503 in step S406. Then, a checksum of the read image data is generated and compared with the checksum stored in the cache information management table 500. If these checksums match as a result of the comparison between the checksums, it is determined that there is no change in the image data. If the checksums do not match as a result of the comparison, and if the image data cannot be read based on the file path stored in the cache information management table 500, it is determined that the image data has changed.

  If the result of determination in step S406 is that there is a change in the image data, the client terminal 102 executes the same processing as in steps S402 to S403 described above. If a record with the same data ID is already stored in the cache information management table 500, it is updated with a new file path and checksum.

  If the result of determination in step S406 is that there is no change in image data, the client terminal 102 acquires image data from the hard disk 209 in accordance with the file path stored in the cache information management table 500 in step S407.

  In step S408, the client terminal 102 controls to display the image data acquired in step S407 on a pop-up screen.

  As described above, in the present embodiment, the consistency between the cache data of the client terminal and the data of the server device is confirmed, and the cache data of the client terminal or the data of the server device is Playback control is performed so that either one is selectively played back.

(Second Embodiment)
In this embodiment, the client terminal 102 does not manage the image data acquired and cached from the image management server apparatus 101 as in the first embodiment, but the image provided by the image management server apparatus 101 to the client terminal 102. A case of managing data will be described. In the present embodiment, description of the same configuration as that of the first embodiment will be omitted, and a configuration unique to the present embodiment will be described in detail.

  A procedure in which the image management server apparatus 101 stores image data uploaded from the client terminal 102 will be described with reference to a flowchart shown in FIG.

  It is assumed that a Web browser has already been activated on the client terminal 102. Then, it is assumed that the image management server apparatus 101 has successfully completed login authentication for the user of the client terminal 102 and the image management server apparatus 101 is in an access state from the client terminal via the network 103. The client terminal 102 is assumed to display a screen for instructing uploading of image data in accordance with the HTML document acquired from the image management server apparatus 101.

  In step S <b> 601, the image management server apparatus 101 receives image data from the client terminal 102 via the network 103. Then, a data ID for uniquely identifying the image data is issued. Here, the client terminal 102 acquires the data ID issued by the image management server apparatus 101 and stores it in the second cache information management table described later in association with the file path of the image data to be uploaded.

  In step S602, the image management server apparatus 101 creates a checksum of the image data received in step S601.

  In step S603, the image management server apparatus 101 determines the file path on the image management server apparatus 101 to the image data received in step S601, the data ID of the received image data, and the checksum created in step S602. Associate and store. These are stored in the first cache information management table 700 as shown in FIG. In FIG. 7, a data ID 701, a file path 702 on the image management server apparatus 101, and a checksum 703 are stored for each image data.

  Next, a procedure for the client terminal 102 to display the image data stored in the image management server apparatus 101 on the screen will be described with reference to the flowchart shown in FIG.

  It is assumed that the Web browser has already been activated on the client terminal 102. Assume that the client terminal 102 has successfully completed login authentication of the user of the client terminal 102 with respect to the image management server apparatus 101 and is accessing the image management server apparatus 101 via the network 103. The client terminal 102 displays a list screen 300 of folders managed by the image management server apparatus 101 as shown in FIG. 3A on the screen of the Web browser according to the HTML document acquired from the image management server apparatus 101. Control.

  In step S800, the client terminal 102 acquires, from the image management server apparatus 101, a data ID for uniquely identifying image data and a checksum of the image data, which are targets of pop-up display, by a user's selection operation. Specifically, in response to the user operating the pointing device, the pointer moves over the folder icon 303. Thereby, the data ID and checksum of the image data representing the folder corresponding to the icon 303 under the pointer are acquired. The HTML document acquired from the image management server apparatus 101 describes the data ID and checksum of the representative image of each folder, and the client terminal 102 stores the data ID and checksum of the representative image of the designated folder. Read from HTML document.

  In step S801, the client terminal 102 checks the second cache information management table 900 as shown in FIG. 9, and determines whether image data corresponding to the data ID acquired in step S800 is stored. The second cache information management table 900 in FIG. 9 associates the data ID 901 with the file path 902 to the image data on the client terminal 102 for the image data stored in the hard disk 209 of the client terminal 102. Store.

  If it is determined in step S801 that image data corresponding to the data ID acquired in step S800 is not stored in the hard disk 209 of the client terminal 102, the process proceeds to step S802. In step S812, the client terminal 102 downloads image data corresponding to the data ID from the image management server apparatus 101. Then, it is determined whether or not the image data can be streamed. For example, prior to the download process, the client terminal 102 determines by receiving a notification from the image management server apparatus 101 that the image data to be downloaded is compatible with streaming playback.

  If the result of determination in step S812 is that streaming playback is not possible, image data corresponding to the data ID is downloaded from the image management server apparatus 101 and stored in the hard disk 209 of the client terminal 102 in step S802. Note that this may be displayed on the screen during the download process.

  In step S803, the client terminal 102 generates a checksum of the image data downloaded in step S802.

  In step S804, the client terminal 102 stores the data ID acquired in step S800 and the file path to the image data downloaded in step S802 on the client terminal 102 in the second cache information management table 900.

  In step S805, the client terminal 102 controls to display the image data downloaded in step S802 on a pop-up screen.

  If the result of determination in step S812 is that streaming playback is possible, in step S813 the client terminal 102 controls to reproduce the pop-up screen 302 while receiving image data from the image management server apparatus 101. Also, the image data is downloaded from the image management server apparatus 101 in the background, and the same processing as in steps S803 and 804 is executed. As a result, even if it takes time to download the image data, the image data can be reproduced on the pop-up screen in parallel therewith, so that it is possible to reduce the time required until the image data is displayed.

  If it is determined in step S801 that image data corresponding to the data ID acquired in step S400 is stored in the hard disk 209 of the client terminal 102, the process proceeds to step S806. In step S806, the client terminal 102 reads the corresponding image data from the hard disk 209 based on the file path stored in the second cache information management table 900. Then, a checksum of the read image data is generated and compared with the checksum acquired from the image management server apparatus 101 in step S800. If these checksums match as a result of the comparison, it is determined that there is no change in the image data. As a result of comparison, if these checksums do not match, and if the image data cannot be read from the hard disk 209 based on the file path stored in the second cache information management table 900, the image data is changed. Judge that there is.

  If it is determined in step S806 that there is a change in the image data, in step S802, the client terminal 102 downloads the image data corresponding to the data ID from the image management server apparatus 101 and stores it in the hard disk 209 of the client terminal 102. Remember. At this time, a new file path different from the file path stored in the second cache information management table 900 is generated, and the newly downloaded image data is stored based on the new file path. Then, the corresponding record in the second cache information management table 900 is updated with a new file path. Thereby, when the user has changed the existing image data, it can be prevented from being overwritten by the newly downloaded image data, and the new image data can be used as a cache image.

  If the result of determination in step S806 is that there is no change in image data, the client terminal 102 acquires image data from the hard disk 209 in accordance with the file path stored in the second cache information management table 900 in step S807.

  In step S808, the client terminal 102 controls to display the image data acquired in step S807 on a pop-up screen.

  As described above, in the first and second embodiments, after the client terminal uploads the image data to the server apparatus, when the client terminal accesses the server apparatus and reproduces the image data, it is already stored in the client terminal. Use the image data. As a result, the communication load between the server device and the client terminal can be reduced, and the time taken until the image data is reproduced on the client terminal can be reduced.

  Furthermore, in the first and second embodiments, it is confirmed whether the image data of the server device and the client terminal match, and if they match, the image data already stored in the client terminal is displayed and does not match The image data is reacquired. Thus, even when image data is edited by a user operation on the client terminal and no longer corresponds to the image data in the server device, the consistency of the image data to be displayed can be maintained.

  In addition, the objective of this invention is achieved by performing the following processes. That is, a storage medium storing a program code for realizing the functions of the above-described embodiments is supplied to a system or apparatus, and a program code (or CPU or MPU) of the system or apparatus is stored in the storage medium. Is a process of reading.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Moreover, the following can be used as a storage medium for supplying the program code. For example, floppy (registered trademark) disk, hard disk, magneto-optical disk, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM or the like. Alternatively, the program code may be downloaded via a network.

  Further, the present invention includes a case where the function of the above embodiment is realized by executing the program code read by the computer. In addition, an OS (operating system) running on the computer performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Cases are also included.

  Furthermore, the present invention includes a case where the functions of the above-described embodiment are realized by the following processing. That is, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

It is a block diagram which shows an example of a structure of the data communication system which concerns on one Embodiment of this invention. It is a block diagram which shows an example of a structure of the information processing apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows an example of the folder list screen which concerns on one Embodiment of this invention. It is a flowchart figure which shows an example of the procedure in which the client terminal concerning one Embodiment of this invention displays an image on a pop-up screen. It is a figure which shows an example of the cache information management table which concerns on one Embodiment of this invention. It is a flowchart figure which shows an example of the procedure in which the image management server apparatus which concerns on one Embodiment of an image receives upload of image data from a client terminal. It is a figure which shows an example of the cache information management table which concerns on one Embodiment of invention. It is a flowchart figure which shows an example of the procedure in which the client terminal concerning one Embodiment of this invention displays an image on a pop-up screen. It is a figure which shows an example of the cache information management table which concerns on one Embodiment of invention.

Explanation of symbols

101 Image management server device 102 Client terminal 103 Network

Claims (5)

A data communication system in which a server device and a client terminal communicate via a network,
The server device
Download means for downloading data to the client terminal;
Generating means for generating a checksum of the downloaded data;
Storage means for storing the data in association with the generated checksum;
Upon receiving a request for downloading data from the client terminal, the transmission terminal comprises a transmission means for transmitting a checksum corresponding to the requested data to the client terminal,
The client terminal is
Storage means for storing data downloaded from the server device;
Comparing means for comparing the checksum transmitted from the server device with the checksum of the data stored in the storage means;
As a result of the comparison, if the checksums match, the data stored in the storage means is reproduced, and if the checksums do not match, control is performed to download and reproduce new data from the server device. A data communication system comprising reproduction control means. The client terminal further comprises display control means for displaying on the screen a folder in which data held by the server device is classified,
The data communication system according to claim 1, wherein the request is performed when a mouse-over operation is performed on the folder. A server device that communicates with a client terminal via a network,
Download means for downloading data to the client terminal;
Generating means for generating a checksum of the downloaded data;
Storage means for storing the data in association with the generated checksum;
Upon receiving a request for downloading data from the client terminal, the transmission terminal comprises a transmission means for transmitting a checksum corresponding to the requested data to the client terminal,
The client terminal compares the checksum transmitted from the server device with a checksum of previously stored data, and if the checksums match as a result of the comparison, reproduces the previously stored data. The server device is characterized in that if the checksums do not match, control is performed so that new data is downloaded from the server device and played back. A method of controlling a server device that communicates with a client terminal via a network,
Downloading data to the client terminal;
Generating a checksum of the downloaded data;
Storing the data in association with the generated checksum;
Receiving a request for downloading data from the client terminal, and sending a checksum corresponding to the requested data to the client terminal,
The client terminal compares the checksum transmitted from the server device with a checksum of previously stored data, and if the checksums match as a result of the comparison, reproduces the previously stored data. A control method, wherein if the checksums do not match, control is performed so that new data is downloaded from the server device and played back. In a computer for realizing a server device that communicates with a client terminal via a network,
Downloading data to the client terminal;
Generating a checksum of the downloaded data;
Storing the data in association with the generated checksum;
When receiving a request for downloading data from the client terminal, a step of transmitting a checksum corresponding to the requested data to the client terminal is executed.
The client terminal compares the checksum transmitted from the server device with a checksum of previously stored data, and if the checksums match as a result of the comparison, reproduces the previously stored data. A program for controlling to download and reproduce new data from the server device if the checksums do not match.

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