JP2537862B2 - Display data reading control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] When data is read from a file storage device to a data buffer and is displayed on the screen, if there is no display data for the next screen based on the screen movement operation on the data buffer, the file storage device I / O processing to read data is required.
In the present invention, in order to reduce the number of input / output processings that occur due to screen movement, the position of the next screen data on the data buffer is centered for each input / output processing.
Furthermore, it is designed to be compatible with the next screen movement.

[Industrial applications]

The present invention relates to a display data read control system in a data processing device, and more particularly to a data read control system from a file storage device to a data buffer accompanying a screen movement operation such as screen scrolling or page turning.

[Conventional technology]

FIG. 4 shows a schematic configuration of a conventional general data processing device to which the present invention is applied. In the figure, 1
Is a data processor, 2 is a main memory, 3 is a data buffer, 4
Is a file storage device, 5 is a data file, and 6 is a display device.

Here, the display capacity of the screen of the display device 6 is, for example, 20 lines (20 records), and the capacity of the data buffer 3 is the display device 6.
Is several times as large as the display capacity of the screen of, for example, 100 records, and the data file 5 stored in the file storage device 4 is significantly larger than the display capacity of the screen of the display device 6. Suppose

In such a case, in order for the user to access a wide range of the data file 5 via the display device 6, the user can perform screen scrolling operations such as scrolling up and down or moving to the previous page or the next page. It is necessary to sequentially switch the displayed data.

However, the data displayed on the display device 6 is read from the file storage device 4 into the data buffer 3 on a record-by-record basis and temporarily stored therein, so that the requested display data of the next screen is changed by the screen operation. If they do not exist, the input / output processing of reading the display data from the file storage device 4 into the data buffer 3 is performed.

FIG. 5 is a flow for explaining a conventional display data reading control system, and FIG. 6 is a specific example based on the flow.

According to this, when moving up the screen (for example, scrolling up), the record of the insufficient data is read and the data buffer is created so that the first line of the next screen becomes the minimum record of the data buffer 3.

When moving down the screen (scrolling down), the record of the insufficient data is read and the data buffer is created so that the last line of the next screen becomes the maximum record of the data buffer 3.

For example, in the example of FIG. 6, as shown in FIG. 6A, the records of record numbers 101 to 200 are stored in the current data buffer, and the record number is stored in the current screen.
Data for records 181 to 200 are displayed. If you scroll down the screen and display the data of the records with record numbers 200 to 219 on the next screen as shown in Figure (b), the contents of the data buffer will be the record number.
The record 219 is updated to be the maximum record on the next screen, that is, the last line (record numbers 101 to 119 are updated to record numbers 201 to 219).

[Problems to be solved by the invention]

In the conventional display data read control method, when the screen is moved beyond the record boundary of the data buffer, the data buffer is updated only by replenishing the insufficient data on the side where the screen is moved. There is. For this reason, if a screen move request is made on the next screen, the data buffer must be updated again.

As described above, in the conventional method, when the screen is continuously moved in the upward or downward direction, the data buffer is updated every time, and the number of input / output processing increases, which causes a problem of decreasing the processing speed. there were.

[Means for solving problems]

According to the present invention, when the display data necessary for moving the screen is not on the data buffer and the data buffer needs to be updated, the display data for the next screen is placed in the center of the data buffer. By replenishing new data from, it is possible to increase the possibility that the display data will be present in the data buffer when the re-screen movement occurs.

 FIG. 1 shows a principle explanatory diagram of the present invention.

In the figure, 3 is a data buffer having a storage capacity of 7 records, 5 is a data file, 6 is a display device having a display capacity of 3 records, and FIG. b) shows a state in which the screen is moved by scrolling up.

In the current state of FIG. 3A, the data buffer 3 stores the records of record numbers 8 to 14, of which the screen of the display device 6 has record numbers 10, 11,
Data for 12 records are displayed. Here, the data display of the records of record numbers 7, 8 and 9 is requested by the upward scroll, but the record of record number 7 does not exist in the data buffer 3.

In the state after scrolling in the figure (b), the data buffer 3 is moved from the data file 5 so that the records of the record numbers 7, 8 and 9 are centered in the logical record number array on the data buffer 5. Records with record numbers 5, 6 and 7 have been read.

In the data buffer 3 of FIG. 10A, the logical data array of all the stored data is the same as the physical data array, and the record number arrays are 8, 9, 10, 11, 12, 13, ,14
Has become. On the other hand, in the figure (b), the logical data array of all the data in the data buffer 3 is 5,6,7,8,9,10,11, but the physical data array is 8 as shown. , 9,
It becomes 10,11,5,6,7 and does not match. Therefore, the data buffer 3 is logically treated as an endless structure, the position of the leading data of the logical data array is managed, and the data 7, 8, 9 in the central part of the logical data array is easily read. I am trying to put it out.

[Action]

According to the present invention, when the screen is moved by scrolling up and down, the data (records) that does not exist in the data buffer among the display data required for the next screen is read from the data file. In contrast, in the present invention, new data is additionally read so that the display data of the next screen is logically centered on the data buffer.

Therefore, when the scroll operation is repeated, the probability that the display data exists in the data buffer increases, and the number of input / output processings for reading records and the total transfer record amount can be reduced.

〔Example〕

 FIG. 2 shows a functional configuration of one embodiment of the present invention.

In the figure, 1 is a data processing device, 2 is a main storage device, 3 is a data buffer, 4 is a file storage device, 5 is a data file, 6 is a display device, 7 is a key input device, 8 is a screen buffer, and 9 is a display. Control unit, 10 is command analysis unit, 11 is screen movement control unit, 1
2 is an input / output processing unit.

The data buffer 3 of the main storage device 2 includes an input / output processing unit.
Under the control of 12, data is read from the data file 5 of the file storage device 4 in record units.

The data displayed on the display device 6 is the data buffer 3
Is transferred to the screen buffer 8 and the screen is output by the display control unit 9.

A command for screen movement instructed from the key input device 7, for example, a cursor key input for instructing scrolling up and down, is analyzed by the command analysis unit 10, and information such as the moving direction and moving amount of the screen is displayed. It is passed to the screen movement control unit 11.

The screen movement control unit 11 calculates the range of the display data of the next screen (the range of record numbers) from the display data of the current screen, the moving direction and the movement amount of the screen, and if the range exists in the data buffer 3. For example, the screen buffer 8 is immediately updated to change the screen display.

However, if even a part of the display data of the next screen does not exist in the data buffer 3, the data is read from the data file 5 of the file storage device 4 and the data buffer 3 is updated. The control flow is shown in FIG.

In FIG. 3 ,: If all the display data of the next screen exists in the data buffer 3, the process ends, and if some of them do not exist in the data buffer 3, the step is executed.

: Calculate the data line located in the middle of the next screen and find the corresponding record number.

: A record number array in which the record number of the data line located in the middle of the next screen is located in the middle of the data buffer 3 is created, the number of the record that needs to be read is obtained from the file storage device 4, and is rewritten for that ( The position on the data buffer 3 is obtained.

: Request the input / output processing unit 12 to read the record of the required number from the file storage device 4 to the specified position of the data buffer 3.

In this way, the screen movement control unit 11 in FIG. 2 optimizes the display data of the next screen on the data buffer 3 to the central position every time it is necessary to read data from the file storage device 4. To do.

〔The invention's effect〕

According to the present invention, when the screen movement operation is repeated, the probability that the display data of the next screen exists in the data buffer is significantly increased. Therefore, the number of input / output processes for reading records from the data file into the data buffer can be reduced. The processing speed can be reduced and the processing speed can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of a display data reading control system according to the present invention, FIG. 2 is a functional block diagram of one embodiment of the present invention, and FIG. 3 is a control of main parts of a screen movement control unit in FIG. A flow chart, FIG. 4 is a schematic configuration diagram of a conventional data processing device, FIG. 5 is a flow chart of a conventional display data reading control system, and FIG. 6 is an explanatory diagram of screen movement by the conventional system. In Figure 1, 3: Data buffer 5: Data file 6: Display device

Claims (1)

(57) [Claims] 1. A file storage device (4) comprising a display device (6), a data buffer (3) having a storage capacity larger than the screen display capacity of the display device (6), and a file storage device (4). In the data processing device (1) that can read the data stored in () into the data buffer (3) in record units and display the data on the display device (6), a part of the data of the next screen specified by the screen movement or If not all exist in the data buffer (3), the file storage (4) to the data buffer (3)
The data to be read from the file storage device (4) to the data buffer (3) is the logical data of all the data in the data buffer (3) that is the result of reading the data. Has a data array that is ordered in the following, and the data that is to be displayed on the next screen is the data of the data array portion that is insufficient to allow the data to be positioned at the center of the logically ordered data array. Display data reading control method characterized by.