JPH064368A - File access device - Google Patents

Abstract

PURPOSE:To provide the file access device of which completeness of a data file is guaranteed. CONSTITUTION:When the data amount of a file demanding the write from a work processing job 1 exceeds the capacity of the data file, an output processing part 4 divides the file records it in an external storage medium 8 as plural data files, prepares an index file storing the file names of the plural data files and file history information concerning the respective data files and asks a file access processing part 5 to record it in the external storage medium 8. When the file requested to read is divided into plural data files and recorded, by referring to the index file, an input processing part 3 verifies whether the file history information of the respective data files is coincident with the file history information of respective data files stored in the file access processing part 5 or not and when they are coincident with each other, the data files are read out of the external storage medium 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file access device for accessing a file in the form of a storage medium, and more particularly to a file access device for dividing a large capacity file into a plurality of data files for storage or reading. It is about.

[0002]

2. Description of the Related Art Conventionally, when it is desired to store a file that exceeds a physical capacity limit per data file on an external storage medium, a file access process is performed in order to expand the capacity limit per file. It was necessary to modify the program, the program to obtain the backup, and the program to recover from the backup file. On the other hand, conventionally, an index file is provided,
A file access device has been proposed which stores data exceeding the physical limit of one file by referring to the index file when accessing the file.

[0003]

However, such a conventional file access device has the following problems.

That is, in general, a backup file is often created by backing up a part or all of the data files of the external storage medium for maintenance of the external storage medium of the computer system. If any of the multiple data file groups is old or changed to a new data file by recovery from this backup file, especially if it is stored in a file divided into multiple data files. , The contents of the original data are changed, and the accuracy of the data cannot be guaranteed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a file access device capable of guaranteeing the integrity of a data file.

[0006]

In order to achieve the above object, the present invention is a file access device for accessing a file in response to a request for writing or reading the file, and a data access device having a predetermined capacity or less. When an external storage medium for storing a data file and first file history information regarding each data file stored in the external storage medium are stored, and a request for writing or updating the data file to the external storage medium is made. Control of writing or updating the requested data file to the external storage medium, rewriting and managing the first file history information relating to the stored data file, and requesting reading of the data file. File access processing means for controlling the reading of the data file,
When the amount of data of a file requested to be written exceeds the capacity of the data file, the file access processing means is configured to divide the file and record it as a plurality of data files in the external storage medium. As a management information for the file, an index file that stores each data file name of a plurality of data files obtained by dividing the file and the second file history information regarding each data file is created and created. Output processing means for recording the index file in the external storage medium, data file operating means for requesting the file access processing means to write or update the data file in the external storage medium, and a read request were made. File that is recorded by dividing the file into multiple data files first If there is, refer to the index file for the file and refer to the second file history information of each data file forming the file and the corresponding data file stored by the file access processing means. File access processing means for verifying whether or not the first file history information of the above is matched, and if the first and second file history information is matched, the data file is read from the external storage medium. There is provided a file access device characterized by having an input processing means for requesting to.

[0007]

According to the present invention, the file access device is constructed as described above, and when the data amount of the file requested to be written is larger than the capacity of the data file, a plurality of data are accessed.
Data files are divided and stored sequentially. When the capacity of one data file reaches the capacity limit, the data file is closed, and the data file name and file history information of the data file (file creation date, file update date, file creation time, file update count, The index file storing the capacity is generated and stored in the external storage medium. Also, when reading a file that is divided and stored in a plurality of data files, the second file history information of the file is read from the index file that stores the file name of the file and stored in the file access means. The first file history information and the second file history information of the file in question are compared, and if they match, the reading of the file is continued. Therefore, even if the data file in the external storage medium is updated by the data file operating means for processing related to backup, etc., the accuracy of the contents of the data file divided into a plurality of files. Can be verified and data defects can be prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a functional block diagram showing the configuration of a file access device according to the present invention. In the figure, 1 is a job processing job, 2 is a large-capacity data access processing unit, 3
Is an input processing unit, 4 is an output processing unit, 5 is a file access processing unit, 6 is a file save / recovery processing unit, 7 is a backup file, 8 is an external storage medium, 9 is an index file group, and 10 is a data file group. .

The large-capacity data access processing unit 2 comprises an input processing unit 3 and an output processing unit 4, and when a large-volume data access request is issued from the job processing job 1, an external storage medium is sent via the file access processing unit 5. 8 index files 9 and data files 10 are accessed. The file access processing unit 5 stores the first file history information (file creation date, file update date, file creation time, file update count, capacity) regarding the data files in the data file group 10 and also manages them. I am doing it. In addition, the file save recovery processing unit 6
Is for writing or reading all or some of the data files to the backup file 7 according to a command from the file access processing unit 5 which receives a backup or a backup file recovery request from the job processing job 1. .

Next, the index file group 9 and the data file group 10 in the external storage medium 8 will be described.
Here, FIG. 2 is a diagram showing the configurations of the index file group 9 and the data file group 10. The index file group 9 includes index files 9-1, 9-2, ...
.., each index file 9-1, 9-
2, the next index file name 21-1, its file history information, data file name 22-11, ...
, 22-1n and their file history information are stored. Further, the data file group 10 includes the data files 10-11, ..., 10-1n, 10-21 ,.
..., 10-2m, .... In this embodiment, the file information of the next index file name 21-1 is written with the file history information about the index file 9-2, that is, the file creation date, the file update date, the file creation time, the file update count, and the like. There is. The file history information of the data file name 22-11 stores the file history information of the data file 10-11 having the data file name. Similarly, the file information of the data file 10-1n having the data file name is stored in the data file name 22-1n. Since the same applies to other index files, description of the other index files will be omitted.

Next, the data access processing of this embodiment will be described. Here, FIG. 3 is a flowchart showing the processing of the input processing unit 3 which performs the input processing of the file to the job processing job 1. In addition, here, the large-capacity data is
The data has a capacity that cannot be stored in one data file 10-11.

First, the input processing unit 3 determines whether or not there is a file open request (step 301). If Yes in step 301,
The file access processing unit 5 is requested to open the index file, and the file access processing unit 5 opens the index file designated by the index file group 9. Subsequently, the file access processing unit 5 selects the data specified by the opened index file.
File history information of file name (file creation date, file update date, file creation time, file update count,
The capacity is obtained and handed to the input processing unit 3. Further, the file history information corresponding to the specified data file name managed by the file access processing unit 5 itself is handed to the input processing unit 3.

The input processing unit 3 checks whether the file history information managed by the file access processing unit 5 and the file history information stored in the index file match (step 303). Step 3
If No in 03, that is, if they do not match, an error is reported to the job processing job 1 (step 305) and the processing is terminated. On the other hand, in step 303, Yes (Ye
s), that is, if they match, the file access processing unit 5 is used to request the opening of the data file. Therefore, the file access processing unit 5 opens a predetermined data file.

When it is judged No in step 301, it is judged whether or not there is a next file input request (step 306). If it is determined in step 306 that there is a file input request, the data specified by the file access processing unit 5 is input.
A request for taking out the record of the data file is requested, and the file access processing unit 5 takes out a record from a predetermined data file of the data file group 10 based on the request and passes it to the job processing job 1 (step 307). On the other hand, if it is judged No in step 306, it is judged whether or not there is a file close request (step 308). In step 308, yes (Y
If it is determined to be es), the file access processing unit 5 is requested to close the index file and the data file that are currently open, and the processing is ended.

FIG. 4 is a flow chart showing the processing of the output processing unit 4 which performs the output processing of the file from the job processing job 1. First, the output processing unit 4 determines whether or not there is a file open request (step 401). If it is determined in step 401 that there is a file open request, the file access processing unit 5 is requested to open the index file,
The file access processing unit 5 opens the designated index file (step 402). Then, the data file is opened using the file access processing unit 5 (step 403).

When it is judged No in step 401, it is judged whether or not there is a file output request (step 404). If YES in step 404, it is checked whether or not the capacity of the opened data file is the limit (step 405). If the limit is not reached, the data is written in the data file (step 409). On the other hand, if the limit is reached, the file access processing unit 5 is requested to close the data file (step 406). The file access processing unit 5 closes the opened data file and
In the index file, the file history information corresponding to the data file name of the data file is rewritten, and the file history information regarding the data file managed by the file access processing unit 5 itself is also rewritten. The output processing unit 4 generates the next data file name (step 407) and requests the file access processing unit 5 to open the data file corresponding to the next data file name (step 407). 408). afterwards,
The file access processing unit 5 writes data to the data file.
Data is written (step 409).

If the answer is NO in step 404, it is determined whether there is a file close request (step 410). When it is determined as Yes in step 410, the file access processing unit 5
On the other hand, the file access processing unit 5 is requested to close the currently opened data file, and the file access processing unit 5 closes the predetermined file (step 411). Finally, in the index file, the file access processing unit is requested to rewrite the file history information corresponding to the data file name of the data file closed in step 411 (step 412). Even in such a case, the file access processing unit 5 itself also processes the data of the closed data file.
Rewrite the file history information corresponding to the file name. Then, the output processing unit 4 uses the file access processing unit 5 to close the index file (step 409) and ends the processing. Note that step 406
Even if it is determined to be No, the processing ends.

[0019]

As described above, according to the present invention, it is possible to prevent the contents of a file stored by being divided into a plurality of data files from being replaced and to guarantee the integrity of the file. The excellent effect that it can be obtained can be obtained.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of a file access device according to the present invention.

FIG. 2 is a diagram showing a configuration of an index file group and a data file group in an external storage medium.

FIG. 3 is a flowchart showing an input process for a job processing job.

FIG. 4 is a flowchart showing an output process from a job processing job.

[Explanation of symbols]

 1 Job processing job 2 Large-capacity data access processing unit 3 Input processing unit 4 Output processing unit 5 File access processing unit 6 File save / recovery processing unit 7 Backup file 8 External storage medium 9 Index file group 10 Data file group

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keio Enomoto 1 Horiyamashita, Hadano City, Kanagawa Prefecture Hitachi Computer Engineering Co., Ltd. (72) Inventor Yu Osawa 1 Horiyamashita, Hadano City, Kanagawa Prefecture Tate Manufacturing Kanagawa Factory

Claims (1)

[Claims] 1. A file access device for accessing a file in response to a request to write or read the file, the external storage medium storing a data file having a predetermined limit capacity or less, and the external storage medium stored in the external storage medium. The first file history information about each data file stored therein is stored, and when the writing or updating of the data file to the external storage medium is requested, the requested data file is stored in the external storage medium. A file that controls writing or updating, rewrites and manages the first file history information relating to the stored data file, and controls reading of the data file when requested to read the data file. The access processing means and the amount of data of the file requested to be written determine the size of the data file. In this case, the file access processing means is requested to divide the file into a plurality of data files and record the plurality of data files on the external storage medium. An output processing means for creating an index file storing each data file name of the data file and second file history information relating to each data file, and recording the created index file in the external storage medium; and the file access processing means. To the external storage medium to request writing or updating of the data file
If the data file operation means and the file requested to be read are the files that have been previously recorded by dividing them into multiple data files, refer to the index file for that file and It is verified whether or not the second file history information of each of the constituent data files and the first file history information of the corresponding data file stored by the file access processing means match, and the first file history information is stored. The file access device further comprises input processing means for requesting the file access processing means to read the data file from the external storage medium when the second file history information matches.