JP2009020723A - Server device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a server-based computing system capable of reducing development cost by avoiding an immoderate design change of a window control program or the like, and accelerating a transmission speed of screen data while maintaining compatibility and interoperability. <P>SOLUTION: This server device transmitting screen information corresponding to a service request from a client device through a network to the client device has: a means distinguishing the kind of a drawing instruction configuring the service request; a means transmitting a display command corresponding to the drawing instruction to the client device when the distinguished kind of the drawing instruction is a drawing instruction allowing drawing update by the display command; a means generating image data according to the drawing instruction when the kind is a drawing instruction not allowing the drawing update by the display command; and a means temporarily storing the generated image data in a frame buffer for displaying them in the client device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  According to the present invention, a client device that makes a service request to a server device that operates an application program and a server device that operates an application program based on a service request from the client device can be connected to each other via a network. The present invention relates to a configured server-based computing system.

  2. Description of the Related Art A server-based computing system (thin client system) that transmits a screen of a server device in real time via a network, displays the screen on a remote client device, and operates the server device remotely as the network speed increases. It is spreading. For example, VNC (Virtual Network Computing) that enables a remote machine desktop to be used from a local machine is an example of the server-based computing system.

  A server-based computing system is a system in which a client device (also referred to as a thin client device) and a server device can be connected to each other via a network, and when a client device makes a service request to the server device. The server device operates data management and an application program based on a service request from the client device (see, for example, Patent Document 1).

  The server device creates display data for the client device and sends it to the client device. In the client device, operation information such as a user's key and mouse device is sent to the server device via the network, and the display data for the client device created on the server device side is received and displayed. The client device only needs to include an input device such as a network device, a display device, a mouse device, or a keyboard. Since no data is stored in the client device, storage such as a hard disk is unnecessary, and an application program is executed. Therefore, the processing load required for the client device is light.

FIG. 1 is a diagram illustrating a configuration of a server-based computing system.
As shown in FIG. 1, the server-based computing system sends input information from an input device such as a keyboard and a mouse to the server device 20 from the client device 10, and the server device 20 executes processing based on the input information. Then, the updated screen information (coordinates, size and image) is sent to the client device 10. The client device 10 reflects the screen information on the display device.

FIG. 2 is a diagram for explaining the outline of the server-based computing system.
As shown in FIG. 2, the client device 10 and the server device 20 are connected to each other via a network (communication network) to form a server-based computing system. When the client device 10 performs wireless communication, the client device 10 communicates with the server device 20 via the relay device 30 and the network.

  In such a server-based computing system, for example, when image data is transferred from the server device 20 to the client device 10, the bandwidth that can be used for image transfer is transmitted by transmitting the updated image data with low image quality. Has been disclosed, and the real-time property of screen transfer is improved, and high-quality image data is transmitted again after low-quality image data is transmitted, thereby making image quality degradation inconspicuous ( For example, see Patent Document 2.)

JP 2005-228227 A JP 2006-246153 A

However, the server-based computing system as described above has the following problems.
FIG. 3 is a diagram for explaining acquisition of conventional image data.

  The conventional server-based computing system as described above is basically the same as the display method in realizing a normal network computer. That is, somewhere in the flow when the server device 20 operates (the expression “HOOK” is often used), display data for the client device 10 is created based on the captured data, and the network The created display data is transmitted to the client apparatus 10 via

  More specifically, as shown in FIG. 3, first, the application program 31 running on the server device 10 issues a drawing command for drawing a screen to the window control program 32. The window control program 32 issues a drawing command to the client device display device driver 33. The client device display device driver 33 converts the data into pixel data, stores the data in the client device frame buffer 34, and the data is displayed on a monitor device or the like.

In the flow as described above, there are mainly the following three methods that the server apparatus 10 which is a conventional network computer performs HOOK.
The first system is a system called HOOK for an API (Application Program Interface) between the application program 31 and the window control program 32, which is called API HOOK.

  In the first method, the drawing command issued by the application program 31 to the window control program 32 is transferred to the network as it is, and the processing result screen is displayed by causing the client device 20 to have the same function as the window control program 32. become.

  However, in this first method, since the window control program 32 is highly dependent on the computing environment, if the environment is different between the client device 20 and the server device 10, the interoperability between the two is impossible. There was a problem. Furthermore, since the drawing command in the API layer cannot be compressed, a huge amount of data is transmitted to the network, which causes a problem of reducing the system performance.

The second method is a method for HOOK the window control program 32.
In the case of the second method, the window control program 32 is independently developed or the existing window control program 32 is improved, the drawing command received from the application program 31 is controlled, and it is transmitted to the client device 10 via the network. It will be.

  However, this second method has a high development cost for the window control program 32, and when a new library or the like appears in the application program 31, it is necessary to improve the window control program 32 each time. It has been difficult to take measures and the development cost has increased. In addition, similar to API HOOK, pixel data is difficult to handle in this layer, and there is a problem that it is difficult to compress data.

The third method is a method in which the client device frame buffer 34 storing pixel data to be drawn is HOOKed and screen pixel data is transmitted.
In the case of the third method, the pixel data is transmitted regardless of the environment, so the compatibility problem between the environments is considerably reduced.

  However, in the case of the third method, it is necessary to transmit all the pixel data in the update area even with a very simple drawing command. Since the pixel data has a huge amount of data compared to the rendering command, there is a problem that the network load increases even if compression is applied. Further, since the load of the compression process itself is high, there is a problem that the performance of the server device 10 is thereby lowered.

  The present invention has been made in view of the above problems, and avoids undue design changes of the application program 31 and the window control program 32, thereby reducing development costs and maintaining interoperability and compatibility. It is an object of the present invention to provide a server-based computing system capable of increasing the transmission speed of screen data by controlling both a rendering command with a small amount of data and pixel data with high interoperability.

The present invention employs the following configuration in order to solve the above problems.
That is, according to one aspect of the present invention, the server device of the present invention is a server device that transmits screen information corresponding to the service request to the client device based on a service request from the client device via a network. When the drawing command type discriminating unit discriminates the type of the drawing command that constitutes the service request, and the drawing command type discriminated by the drawing command type discriminating unit is a drawing command that can be updated by a display command. A display command transmission means for transmitting a display command corresponding to the drawing command to the client device, and a type of the drawing command determined by the drawing command type determining means is a drawing command that cannot be updated by a display command. Image data generation means for generating image data in accordance with the drawing command, and the image data generation Characterized in that it comprises an image data storing means for temporarily stored in the frame buffer for displaying the image data generated by the means by said client device.

  The server device of the present invention preferably further comprises image data transmission means for transmitting image data temporarily stored in the image data storage means to the client device.

  In the server device of the present invention, the drawing command type determination unit may be configured based on a table storing a correspondence relationship between the client device and the drawing command and information indicating whether drawing update is possible or not. It is desirable to determine the types of drawing commands that make up the service request.

In the server device of the present invention, it is preferable that the image data generation unit generates image data by executing arbitrary compression processing.
According to another aspect of the present invention, the program of the present invention is a server device computer that transmits screen information corresponding to the service request to the client device based on a service request from the client device via a network. If the drawing command type discriminating means for discriminating the type of drawing command constituting the service request, the drawing command type discriminated by the drawing command type discriminating means is a drawing command that can be updated by a display command, A display command transmission means for transmitting a display command corresponding to a drawing command to the client device; and if the type of the drawing command determined by the drawing command type determining means is a drawing command that cannot be updated by a display command, the drawing command Image data generation means for generating image data according to a command, said image data generation Is a program for functioning as the image data storage means for temporarily stored in the frame buffer for displaying the image data generated by the stage at the client device.

  According to the present invention, by avoiding an undue design change of the application program 31 and the window control program 32, the development cost is reduced, and while maintaining the interoperability and compatibility, the rendering command and the interoperability with a small amount of data are maintained. By controlling both of the high pixel data, the screen data transmission speed can be increased.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, an outline of an embodiment of the present invention will be described.
The server device 20 to which the present invention is applied is a server device 20 that transmits screen information corresponding to the service request to the client device 10 based on a service request from the client device 10 via a network. The server device 20 includes a device driver that determines the type of drawing command, generates a display command or pixel data according to the type, and transmits the display command or pixel data to the client device 10.

FIG. 4 is a diagram illustrating an outline of a hardware configuration of the client device 10.
In FIG. 4, a client device 10 includes a CPU (Central Processing Unit) 302, an input device 303 for inputting various data and signals, a display device 304 for displaying images and other information, In addition to a program for executing processing executed in the client device 10, an image to be displayed on the ROM 305, RAM 306, and display device 304 in which a control program for controlling and executing each function of the client device 10 is temporarily stored. A frame buffer RAM 307 for storing, a communication I / F 308 for connecting to a network such as a wireless LAN or a cellular phone network, an external storage device 309 for recording various information including image data and communication data, and an auxiliary storage device 310 are provided. It is configured to be connected to the bus 301, and the CPU 302 Are your.

FIG. 5 is a diagram illustrating an outline of a hardware configuration of the server device 20.
In FIG. 5, the server device 20 executes a process executed by the CPU 202, an input device 203 for inputting various data and signals, a display device 204 for displaying images and other information, and the server device 20. In addition to the program, a ROM 205 storing a control program for controlling and executing each function of the server device 20 and table data, a RAM 206 storing a frame buffer (client device frame buffer 34) for the client device 10, and the like. , A VRAM 207 for temporarily storing an image to be displayed on the display device 204, a communication I / F 208 for connection to a network such as a LAN, an external storage device for recording various information including image data and communication data 209 and auxiliary storage device 210 are connected to the bus 201. Is, CPU 202 is controlling these units.

Next, the present invention will be described more specifically. The present invention is realized as a server process executed in the server device 20.
FIG. 6 is a diagram for explaining the outline of the present invention.

  In FIG. 6, an application program 31 and a window control program 32 provided in the server device 20 to which the present invention is applied are the same as the conventional application program 31 and the window control program 32.

  The server device 20 to which the present invention is applied further includes a device driver 60. The device driver 60 includes a device-window I / F (interface) 61 that is an interface with the window control program 32 and a main module 62.

  The device-window I / F 61 is the same as an interface for a normal video driver. Usually, the interface with the window control program 32 is device-independent, and the difference between OSs is quite small, so interoperability between systems can be expected.

  An example of a drawing command with the window control program 32 is shown below. These drawing commands are provided in common to all systems at least for basic ones even if there are some differences in the window control program 32.

PolyFillRect: A drawing command that fills a rectangular area with a single color
PolyFillArc: Arc drawing command
PaintWindowBackground: A drawing command that paints the background of a window

CopyWindow: a drawing command for copying a window to another area on the screen. The main module 62 has a function of transmitting image data and a drawing command to the client device 10 in addition to image data processing described later with reference to FIG. An interaction function with the compression circuit 35 is realized.

  The client device frame buffer 34 stores screen data converted into pixel data. The pixel data stored here is compressed by the compression circuit 35 and then sent to the client device 10 via the network. The compression circuit 35 may be realized by software, and the compression function mounting method itself may be anything.

Here, before explaining the flow of screen data processing to which the present invention is applied, some prerequisite technologies will be described.
Screen data is mainly classified into two types: Display Command Update (screen update by display command) and Pixel Data Update (screen update by pixel data). The former “screen update by display command” is intercepted from the interface portion with the window control program 32, and transmits drawing vector data together with a drawing command. The pixelization process is executed by the client device 10.

FIG. 7 is a diagram illustrating an example of screen update by a display command.
As the screen update by the display command, for example, COPY: a display command for copying an image of a certain area to another area (FIG. 7A), SFILL: a display command for filling a rectangle with a single color (FIG. 7) (B)), PFILL: There is a display command (FIG. 7 (C)) for painting a rectangular area with a fixed pattern. However, if it can be handled by an interface with the window control program 32 in essence, This is not the case.

  In the latter “screen update by pixel data”, a rectangle in the update area is cut out from the pixel data stored in the frame buffer 34 for the client device, and compression processing is performed by the compression circuit 35 using a certain algorithm. The compressed pixel data is transmitted to 10. In this case, the client device 10 expands the received data and displays the pixel data on the screen.

FIG. 8 is a diagram for explaining the flow of drawing data.
In FIG. 8, first, the window control program 31 issues a drawing command to the main module 62 via the device-window I / F 61 provided in the device driver 60.

  If this drawing command is not a Display Command Update (screen update by display command) but a Pixel Data Update drawing command (drawing command 1 in FIG. 8), the drawing command (drawing command 1) ), And the generated image data is temporarily stored in the client device frame buffer 34. This drawing command includes an update area (coordinates, width, height). Then, the main module 62 cuts out the image data in the update area from the client device frame buffer 34 and passes it to the compression circuit 35. Thereafter, the compressed image data is received from the compression circuit 35, and the compressed image data is transmitted to the client device 10.

  On the other hand, when the drawing command issued by the window control program 31 is not a Pixel Data Update (screen update by pixel data) but a Display Command Update (screen update by display command) drawing command (drawing command 2 in FIG. 8). The display command corresponding to the drawing command (drawing command 2) is transmitted to the client device 10.

Next, the present invention will be described more specifically. The present invention is realized as a server process executed in the server device 20.
FIG. 9 is a flowchart showing the flow of screen data processing executed in the server device 20, FIG. 10 is a diagram showing an example of a table group for determining command transmission, and FIG. FIG. 10 is an example of a client device table in which a client device ID uniquely assigned to each client device 10 for identifying the client device 10 and a client device name indicating the type of the client device 10 are associated with each other. FIG. 10B is an example of a drawing command table in which a drawing command ID uniquely assigned to identify a drawing command is associated with the drawing command. FIG. 10C illustrates a drawing command ID and a client device. A command transmission permission / inhibition test in which a combination of the ID and information indicating whether transmission by a display command is possible (command transmission is possible?) Is associated. It is an example of a bull.

  First, in step S901 of FIG. 9, the main module 62 included in the device driver 60 of the server apparatus 20 receives a drawing command from the window control program 32. In step S902, the received drawing command is displayed as a Display Command Update (display command). It is determined whether or not the drawing command (drawing command 2) is possible.

  Whether or not the drawing command is a drawing command (drawing command 2) capable of Display Command Update (screen update by a display command) is determined by referring to a table group as shown in FIG. For example, when the drawing command is “PolyFillArc (arc drawing command)” for the personal computer (PC) as the client device 10, the client device “PC” from the client device table in FIG. With reference to ID “0”, the drawing command ID “1” of “PolyFillArc” is referred to from the drawing command table of FIG. Then, by referring to “FALSE” corresponding to the combination of the drawing command ID “1” and the client device ID “0” from the command transmission availability table of FIG. Can be determined.

Returning to the description of FIG.
In step S902, when it is determined that the drawing command (drawing command 2) is not possible (Display command update) (step S902: NO), that is, the pixel data update (screen update by pixel data) drawing command. If it is determined that it is (rendering command 1), in step S903, image data is generated according to the rendering command (rendering command 1), and the generated image data is temporarily stored in the client apparatus frame buffer 34. In step S904, the image data in the update area is cut out from the client device frame buffer 34 and transferred to the compression circuit 35.

  Thereafter, in step S905, the image data compressed by the compression circuit 35 is received. In step S906, the compressed image data is transmitted to the client device 10, and the process returns to step S901 to wait for the next drawing command.

  On the other hand, if it is determined in step S902 that the drawing command (drawing command 2) is capable of Display Command Update (screen update by display command) (step S902: YES), the subroutine “command distribution process” is executed in step S907. Execute.

FIG. 11 is a flowchart showing the flow of the subroutine “command distribution process”.
First, in step S1101, window drawing information is confirmed. In step S1102, it is determined whether the background of the window is a single color.

  If it is determined that the background of the window is a single color (step S1102: YES), in step S1103, the display command “SFILL” (see FIG. 7B) is transmitted to the client device 10, and the step of FIG. The process returns to S901 and waits for the next drawing command.

  On the other hand, if it is determined that the background of the window is not a single color (step S1102: NO), it is determined in step S1104 whether the background of the window is a single pattern.

  If it is determined that the background of the window is a single pattern (step S1104: YES), in step S1105, the display command “PFILL” (see FIG. 7C) is transmitted to the client device 10. Returning to step S901 in FIG. 9, the next drawing command is awaited.

  On the other hand, if it is determined that the background of the window is not a single pattern (step S1104: NO), the corresponding display command does not exist, so the process proceeds to step S903 in FIG.

  In order to realize such a flow, the conventional window control program 32 had to be improved or created from scratch in the prior art, so interoperability between different platforms and development costs. However, the present invention uses the unified device-window I / F 61 as an interface with the existing window control program 32, and thus improves the existing window control program 32 as described above. Realization of distribution.

  As described above, the server device 20 to which the present invention is applied does not modify the existing window control program 32, and performs Display Command Update (screen update by display command) and Pixel Data Update (screen by pixel data). Update) can be used appropriately, so that it is possible to achieve all of improvement in performance of the entire server-based computing system, reduction in development cost, and improvement in interoperability between systems.

  As described above, the embodiments of the present invention have been described with reference to the drawings. However, in the above-described embodiments of the present invention, a hardware, a DSP (Digital Signal Processor) board or a CPU board is used as one function of the server device. It can be realized by firmware or software.

  Further, the server device to which the present invention is applied is not limited to the above-described embodiment as long as the function is executed, and even a single device or a system composed of a plurality of devices is integrated. Needless to say, the apparatus may be a system that performs processing via a network such as a LAN or a WAN.

  It can also be realized by a system including a CPU, ROM or RAM memory connected to a bus, an input device, an output device, an external recording device, a medium driving device, and a network connection device. That is, the ROM, RAM memory, external recording device, and portable recording medium in which the software program for realizing the system of the above-described embodiment is recorded are supplied to the server device, and the computer of the server device reads the program. Needless to say, it can also be achieved through implementation.

  In this case, the program itself read from the portable recording medium or the like realizes the novel function of the present invention, and the portable recording medium or the like on which the program is recorded constitutes the present invention.

  Examples of portable recording media for supplying the program include flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, DVD-ROMs, DVD-RAMs, magnetic tapes, and nonvolatile memory cards. Various recording media recorded via a network connection device (in other words, a communication line) such as a ROM card, electronic mail or personal computer communication can be used.

  The computer (information processing apparatus) executes the program read out on the memory, thereby realizing the functions of the above-described embodiment, and an OS running on the computer based on the instructions of the program. Performs part or all of the actual processing, and the functions of the above-described embodiments are also realized by the processing.

  Furthermore, a program read from a portable recording medium or a program (data) provided by a program (data) provider is stored in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. After being written, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing based on the instructions of the program, and the functions of the above-described embodiments are also realized by the processing. obtain.

  That is, the present invention is not limited to the embodiment described above, and can take various configurations or shapes without departing from the gist of the present invention.

It is a figure which shows the structure of a server base computing system. It is a figure for demonstrating the outline | summary of a server base computing system. It is a figure for demonstrating acquisition of the conventional image data. 2 is a diagram showing an outline of a hardware configuration of a client device 10. FIG. 2 is a diagram illustrating an outline of a hardware configuration of a server device 20. FIG. It is a figure for demonstrating the outline | summary of this invention. It is a figure which shows the example of the screen update by a display command. It is a figure for demonstrating the flow of drawing data. 4 is a flowchart showing a flow of screen data processing executed in the server device 20. It is a figure which shows the example of the table group for discriminating command transmission. It is a flowchart which shows the flow of a subroutine "command distribution process."

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Client apparatus 20 Server apparatus 30 Relay apparatus 31 Application program 32 Window control program 33 Client apparatus display device driver 34 Client apparatus frame buffer 35 Compression circuit 60 Device driver 61 Device-window I / F (interface)
62 Main module 201 Bus 202 CPU
203 Input device 204 Display device 205 ROM
206 RAM
207 Frame buffer RAM
208 Communication I / F
209 External storage device 210 Auxiliary storage device 301 Bus 302 CPU
303 Input device 304 Display device 305 ROM
306 RAM
307 Frame buffer RAM
308 Communication I / F
309 External storage device 310 Auxiliary storage device

Claims (5)

Based on a service request from a client device via a network, the server device transmits screen information corresponding to the service request to the client device,
A drawing command type discriminating means for discriminating types of drawing commands constituting the service request;
A display command transmission unit that transmits a display command corresponding to the drawing command to the client device when the type of the drawing command determined by the drawing command type determination unit is a drawing command that can be updated by a display command;
If the drawing command type determined by the drawing command type determining means is a drawing command that cannot be updated by a display command, image data generating means for generating image data according to the drawing command;
Image data storage means for temporarily storing image data generated by the image data generation means in a frame buffer for displaying on the client device;
A server device comprising: further,
Image data transmission means for transmitting image data temporarily stored in the image data storage means to the client device;
The server device according to claim 1, comprising:   The drawing command type discriminating unit is configured such that the type of drawing command constituting the service request is based on a table storing a correspondence relationship between the client device and the drawing command and information indicating whether drawing update is possible or not. The server device according to claim 1, wherein the server device is discriminated.   The server apparatus according to claim 1, wherein the image data generation unit generates image data by executing an arbitrary compression process. Based on a service request from a client device via a network, a computer of a server device that transmits screen information corresponding to the service request to the client device.
A drawing command type discriminating means for discriminating types of drawing commands constituting the service request;
A display command transmission unit that transmits a display command corresponding to the drawing command to the client device when the type of the drawing command determined by the drawing command type determination unit is a drawing command that can be updated by a display command;
Image data generating means for generating image data in accordance with the drawing command when the type of the drawing command determined by the drawing command type determining means is a drawing command that cannot be updated by a display command;
Image data storage means for temporarily storing the image data generated by the image data generation means in a frame buffer for displaying on the client device;
Program to function as.