JPH0496149A - File compression processing method - Google Patents

Abstract

PURPOSE:To surely execute the compression of a file without obstructing other processing by starting automatically a file compression processing, and also, executing its processing as a task whose priority is the lowest, at the time of down-loading a data file. CONSTITUTION:From a data base 12 of a host device 10, a prescribed data file is read out, down-loaded to a split sequence organizing file 30 at a pre scribed timing, and also, after down-loading is finished, a file compression processing of the split sequence organizing file 30 is executed as a task whose priority is the lowest. That is, taking advantage of down-loading of the data file, the file compression processing is actuated, and also, the processing is actuated as a task whose priority is the lowest, therefore, in the case other processing is requested, the file compression processing is interrupted, and as a result, the processing is advanced by utilizing an idle time of the device. In such a way, the file compression processing can be executed surely and automatically without obstructing other processing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a file compression processing method for compressing a data file stored in a divided sequential file format at a predetermined timing in an information processing apparatus.

(Prior Art) Among the data files that an information processing device holds in a storage device, there are some in which a wasted area is generated every time an update or other processing is performed. In order to remove the useless parts, file compression processing is performed.

FIG. 2 shows a block diagram of a conventional general system to which the method of the present invention is applied.

The system shown in the figure consists of a higher-level device 10 and a lower-level device 20 connected via a communication line 11.

A database 12 is connected to the host device 1o. The lower device 20 is provided with a processor 22 , a keyboard 23 , a magnetic disk device 24 , and an interface (I/F) 25 connected via a path line 21 .

The processor 22 is a circuit for controlling the operation of the lower-order device 20. The key fob 23 includes various keys operated by an operator to control the lower-level device 20. The interface 25 is a circuit that controls data exchange with the host device 10 via the communication line 11. The magnetic disk device 24 is provided with a divided sequential file 30 for storing data files used by the lower device 20.

In this figure, there are provided a compression source file 31 that is directly accessed by the processor 22 during operation, and a compression destination file 32 that is transcribed during data file compression work. The compression source file 31 is an active file, and the compression destination file 32 is a temporary file created only during compression processing.

For example, in a counter terminal of a financial institution or a printer for outputting distributed data, screen data, form data, etc. are stored in the division order organization file 30, and an operator operates the keyboard 23 to input various data. Then, the variable data obtained at that time and the divided sequential organization file 30
The screen data or form data stored in the image data are combined and displayed on the display 26 or printed out on the printer 27.

The screen data, form data, etc. used in this way are partially or significantly changed for various reasons.

In this case, the updated screen data and form data stored in the database 12 of the higher-level device 10 are transferred to the lower-level device 20 at a predetermined timing and stored in the division order organization file 30.

FIG. 3 shows the structure of a divided sequential file and an explanatory diagram of its compression processing operation.

As shown in the upper part of the figure, the division sequential organization file is composed of a directory part (2) and a substance part (2). The write start address, data length, etc. of predetermined data files A, B, and C are stored in the directory section (2). The entity part ■ contains data files A and B defined in the directory part ■.

C is stored.

For example, if data files A, B, and C are different screen data, initially these screen data are
The files are written sequentially from the beginning of the divided sequential file without any gaps. However, when part of the screen data is rewritten due to updating or the like, a new data file is written (downloaded) from the next part of the most recently written data file in this divided sequential file. Then, the pointer indicating the write start address of the corresponding data file in the directory section (3) is rewritten.

Split sequential files are used in this way, in practice:
Whenever new screen data is downloaded as a result of updating the screen data, an empty area is created in the middle.

In other words, in the figure, the hatched data file part■
An empty area without hatching occurs between , ■, and ■. If a lot of free space like this occurs, there will be a large waste of this divided sequential file, and if a new update is required, there will be a shortage of free space after the most recently written data file, and the download will be delayed. may become impossible.

Therefore, in order to make effective use of files, file compression processing is executed in response to an operator's instruction or the like. To do this, as shown in the figure, the data in the file 31 with the compression source file name "AAAAA" is sequentially read and written into the file 32 with the compression source file name "AAAAAW". In this case, fill up the free space, convert and update all the pointers in the directory part ■, and start from the beginning of the real part ■.
Enable data files ■, ■, ■ to be written.

(Problems to be Solved by the Invention) However, the above file compression process requires a longer time than other processes. Therefore, if the operator starts file pressure line processing at an appropriate timing,
Each time, the operation of the device stops for a long time. Therefore, for example, in a system where files are updated when the device is powered on, if file compression processing is forcibly executed every time a file is updated, it will take a considerable amount of time before the device starts operating. The problem was that it required .

In addition, in a system that performs file compression processing when performing periodic maintenance and inspection work, if such file compression processing is neglected due to a work error,
When updating a file, the file becomes full and cannot be updated. This poses a major problem in the operation of the device.

The present invention has been made with attention to the above points, and it is possible to reliably and automatically execute file compression processing at a predetermined timing without causing any operational failure and without interfering with other processing. The purpose is to provide a file compression processing method.

(Means for Solving the Problems) A first method of the present invention reads a predetermined data file from a database of a host device, downloads it to a division sequential organization file at a predetermined timing, and after the download is completed, the The present invention is characterized in that file compression processing of the divided sequential file is executed as a low priority task.

In addition, in the second method, after completing the compression process of the split sequential file by reading the data of the compression source file that is currently in operation and writing it to a temporary compression destination file, the compression source file name and the compression source file are When exchanging names,
Change one of the file names to the third file name, then change the other file name to the desired file name in order, until the temporary compression destination file is replaced with the actual file. This method is characterized in that, for each process of changing a file name, a file rewriting flag is set to identify the process.

(Function) In the method of the present invention, file compression processing is started when a data file is downloaded. still,
This file compression process is started as a task with the lowest priority. Therefore, if other processing is requested, the file compression processing will be interrupted, and as a result, the processing will proceed using the available time of the device.

In addition, after the compression process is completed, the file name of the compression destination file must be changed to the file name of the compression source file that is currently in operation. Set the file rewriting flag to recognize the change process. This makes it possible to perform file compression processing over a long period of time using free time, and even if work is interrupted at any point during file name rewriting, file name rewriting can be continued from the point of interruption.

(Example) Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 is a flowchart showing the file compression processing operation of the present invention.

The method of the invention is carried out in a device such as that already shown in FIG. That is, a predetermined data file is read from the database 12 of the host device 10, downloaded to the division sequential organization file 30 at a predetermined timing, and compression processing is executed to eliminate the free space created by the download.

First, when the power of the apparatus is turned on, a file oven process is performed to start the operation of the apparatus (step Sl). This file oven treatment is related to the second method of the present invention and will be described in detail later. Substantially, after this step S1 is completed, the compression source file 31 in the magnetic disk device 24 as shown in FIG. 2 is opened as an active file.

Next, it is determined whether download is necessary or not (step S2). If downloading is not necessary, the device simply proceeds to normal processing.

On the other hand, if downloading is necessary, the file is updated by downloading in step S3.

This is done by the higher-level device 10 shown in FIG. 2 reading a predetermined data file from the database 12 and
This is done by transferring the data file to be updated and storing the data file to be updated in the corresponding compression source file 31.

In step S2 above, when determining whether downloading is necessary, the version numbers of screen data, form data, etc. held in the terminal and the versions of these data held in the host device 10 are used. A match is made with the number.

If the version numbers match, it is determined that downloading is not necessary; if they do not match, it is determined that downloading is necessary. Such a determination is executed immediately after the power is turned on or the like.

The specific procedure for downloading is as already explained in FIG.

Thereafter, file compression processing is started (step S4).

That is, in the present invention, when a download is executed, file compression processing is automatically started. In this case, the file compression processing program is started as a task with the lowest priority when compared with the various other processes of the lower-level device 20 shown in FIG.

Therefore, for example, when an operator performs a deposit/withdrawal process using the keyboard 23 shown in FIG. Continued. By setting such conditions, file compression processing is automatically and unconditionally executed, and is automatically completed without interfering with any other processing. Therefore, if there is a new download request after that, a situation in which the free space of the divided sequential file becomes insufficient is prevented.

This file compression process is performed on the actual compression source file 31 and the temporary compression destination file 32 shown in FIG.
However, if the power is cut off or a new download is executed, the file compression process may be interrupted and become invalid. In such a case, after the file is updated by downloading, the file compression process will be started again.

Returning to FIG. 1, the explanation of the operation of the file compression process will be continued.

When the file compression process is started, first, the pointer etc. of the direct section (■) shown in Fig. 3 are initialized (
Step S5). Then, compress source file “AAAAAA”
One block of data is read from "31" (step S6). Next, the data is stored in the compressed file "AAA".
One block is written to AAW”32 (step S7)
.

After that, the pointer is updated (step S8), and it is determined whether or not the compression has ended (step S9). Then, the processes from step S6 to step S9 are repeated, and when all the compression processes are completed, the file The compression completion flag is turned on (step 5IO).

When file compression is completed according to the procedure shown in FIG. 1, the apparatus switches the compressed destination file 32 (FIG. 2) to a new active file and starts processing. At this point, the existing compression source file disappears.

Now, the second invention will be explained.

When the compression process as described above is completed, it is necessary to exchange the file name previously assigned to the compression source file with the file name of the compression destination file.

The reason why such file name exchange is necessary is that the system itself executes various processes based on the file name of the compression source file. Further, the program for compression processing operates by specifying the names of the compression source file and the compression destination file.

As explained earlier, even if the operation is interrupted for some reason during the file compression process and the compression process becomes invalid, there is still enough free space in the compression source file 31 to allow new downloads. There will be no inconvenience if you leave it as long as it exists. That is, the compression process may be executed again at the time of the next download.

However, the compression source file 31 and the compression destination file 3
If a failure or the like occurs during the process of rewriting the name of file 2 and the process is interrupted, in the worst case, both files may become unusable.

The second invention was made to solve this problem.

In this case, in the second method of the present invention, the process of changing the file name is divided, and for each changing process, a file rewriting flag is set to identify that process. If a failure occurs, the rewriting process can be continued from the state specified by the file rewriting flag.

When the entire apparatus is operating normally, it is not allowed that the name of the compression source file and the name of the compression destination file are the same even at some point in time. For this purpose, file names are rewritten using the following procedure.

In the embodiment, it is assumed that the file name is changed when the device is powered off. When powering down a device normally, post-processing of the operation of each part of the device is typically performed. This post-processing includes file name change processing. Therefore, when the device is powered on and a download is performed, compression processing is executed, and the name of the compressed file is rewritten when the device is powered off. If there are no frequent downloads while the device is operating,
Such a method can be said to be most suitable for automating compression processing.

FIG. 4 shows a flowchart illustrating the setting operation of such a file rewriting flag.

As described above, this process is executed when an instruction to turn off the power to the lower-order device 20 shown in FIG. 2 is input.

That is, first, it is determined whether the file compression completion flag is on (step Sl). If the file compression completion flag is not on, even if file compression processing has been in progress up to that point, it will be ignored. If the file compression completion flag is on, the file rewriting flag is set to "1" (step S2). Here, the file name of the compression source file is changed from "AAAAAA" to the third file name "AAAAAR" (step S3
).

Next, the file rewriting flag is set to "2" (step S4). This time, change the compression source file name to “AAAAAW
” to “AAAA” (step S5). Then, the file rewriting flag is set to “3” (step S6).

Next, change the file name of the compression source file that had been changed from “AAAAAR” to “AAAAAW”.
” (step S7).

Thereafter, the file rewriting flag is set to "0" and the file compression completion flag is turned off (step SS).

By performing the above processing, the exchange of file names between the compression source file and the compression destination file is completed.

Thereafter, the power is automatically turned off (step S9). As a result, when the device is newly activated, the processing will be executed based on the divided sequential file after the compression processing is completed.

Since the process shown in FIG. 4 is executed immediately before the device is powered off, there is no problem even if the name of the file currently in operation disappears. Furthermore, since the file names are exchanged after one file name is changed to the third file name, problems such as the same file name being given twice do not occur.

If the device is powered off normally, the rewriting of the file name is completed in this way, but if a failure occurs during this time, the file name may not be rewritten at all, or the file name may not be rewritten in the middle of rewriting. It is possible that the process may end in this state.

Therefore, in the file open process (step S1) shown in FIG. 1, the file status is returned to a normal status.

That is, first, the compression source file and the compression destination file are opened, and depending on the status of the file names, the interrupted rewriting of the file name is completed normally.

FIG. 5 shows an explanatory diagram of the processing operation for recovering the file name change processing. The figure corresponds to the process in FIG. 4, and the operation progresses in the vertical direction.

That is, the file compression completion flag is initially off, turns on when file compression is executed, and turns off again when rewriting of the file name is completed.

While the file name is being rewritten in these processes, the file rewriting flags are set to 1.
2.3. It will be rewritten as O.

In this case, the compression source file name changes from “AAAAAA” to “
It is rewritten as "AAAAAR", "AAAAAW". Further, the compression source file name is rewritten from "AAAAAAW" to "AAAAA".

File open processing (step Sl) shown in Figure 1
In , the file rewriting flag, the opened compression source file name, and the compression source file name are referred to. As a result, for example, if the file rewriting flag is "1", the compression source file name is "AAAAAA", and the compression source file name is "AAAAAAW", step S shown in FIG.
3 has been completed, and it is determined that step S4 has not yet been executed, steps S3 to S8 are executed,
It will be recovered.

If you do the above, the file compression process will start when the data file is downloaded, and once the file compression process is finished, the file name will be rewritten when the power is turned off. Even if the process is interrupted for some reason, the file name rewriting process will be completed normally after the next device is powered on, and the process can be started using the new compressed file.

The present invention is not limited to the above embodiments.

In the above example, the compression source file name is first changed to the third file name, and then the compression source file name is changed to the compression source file name, and then the compression source file name compression is changed to the file name. ing.

However, the compression source file name is changed to -dan, 3rd
There is no problem even if you change the file name to the one before exchanging the names.

Furthermore, the way the file is named, the format of the file rewriting flag, etc. may be freely changed depending on the purpose.

(Effects of the Invention) According to the file compression processing method of the present invention explained above,
When downloading a data file from the database of a host device, file compression processing is automatically started and is executed as a task with the lowest priority. Therefore, files can be reliably compressed without interfering with other processes, reducing the burden on the operator and preventing failures in updating files. In addition, when exchanging the file names of the compression source file and the compression destination file after file compression is completed, a file rewriting flag is set to identify the process for each file name change process, so there is no possibility of any failure. Even if the file renaming process is interrupted due to an error or a forced power cut, recovery is possible, and file destruction due to operational errors caused by automatic file compression can be prevented. can.

[Brief explanation of the drawing]

FIG. 1 is an operational flowchart explaining the file compression processing method of the present invention, FIG. 2 is a system block diagram to which the method of the present invention is applied, FIG. The figure is a flowchart of the file rewriting flag setting operation, and FIG. 5 is an explanatory diagram of the file name change process recovery operation. 10... Upper device, 12... Database, 20.
...Lower device, 30...Divided sequential organization file, 31.
...Compression source file, 32...Compression destination file. Patent applicant Oki Electric Industry Co., Ltd.

Claims (1)

[Claims] 1. Read a predetermined data file from the database of the host device and download it to the division order organization file at a predetermined timing, and after the download is completed, the division order organization is executed as the task with the lowest priority. A file compression processing method characterized by executing file compression processing on a file. 2. When the compression source file name and the compression destination file name are exchanged after completing the compression process of the split sequential file by reading the data of the compression source file that is currently in operation and writing it to a temporary compression destination file. , one of the third
After that, change the file name to the desired file name, and then change the file name to the desired file name in order. Until the temporary compression destination file is replaced with the actual file, each file name change process. A file compression processing method characterized in that a file rewriting flag is set to identify the process.