JPH04145548A - File controlling system - Google Patents

Abstract

PURPOSE:To hold the data required for restoring in-file record management table (FAT) areas even when data destruction occurs in an FAT area by adding data for restoring FAT areas to the leading edge of a data record. CONSTITUTION:When a record R6 is further written in a file A, the record R6 is written in the record storing area 14 of the data area corresponding to a FAT number '9' and the '9' is added as the in-FAT relative record information 12 of the record R5 which is the last record before writing the record R6. In addition, 'FF' is added as the in-FAT relative record information 12 of the record R6. Moreover, the '9' which is the in-FAT relative record information 12 of the record R5 is stored in the in-FAT relative record information storing area 13 of the record storing area 14 of the record R5. Therefore, even when the FAT area is destroyed, the data in the FAT area can be restored automatically by referring to the FAT data which are the pointers indicating next records at the leading edge of each record.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a file control method, and particularly to a file control method for filing code data.

[Conventional technology]

Conventionally, in this type of file, indirect access using an in-file record management table (hereinafter referred to as FAT) area has been performed as a method for efficiently using the code data area.

FIG. 2 is a diagram showing a data file structure of a conventional file control method.

The file in Figure 2 consists of a directory area where information such as file names is stored, a FAT area where information for managing each record in the file is stored, and a data area where records are stored. records R1 to R6 of file A and record F1 of file B.
~F4 are stored.

In Fig. 2, records R1-R4 of the file are stored in the record storage area 14 corresponding to FAT number 11 rOJ~``3'', and R5, R, correspond to FAT number 11 18'', r9''. It is stored in the record storage area 14 of the data area. In order to manage the above-mentioned records, FAT internal core record information 12 is stored in the FAT area. That is, the FAT internal core record information 12, for example, the FAT number "0"
”, the FAT number “1” indicating the storage position of the next record R2 is stored, and the area corresponding to the FAT number “1” stores the FAT number “1” indicating the storage position of the next record R3. The number "2" is stored.

[Problem to be solved by the invention]

In the conventional file control method described above, all records existing in the data area are managed by index data in the FAT, so physical/logical factors such as hardware failure and software runaway may cause the FAT area to become When data is destroyed, the relationship between the index data in the FAT area and the data records in the data area becomes incorrect, making it impossible to obtain the necessary index data in the FAT area and making it impossible to access the data in the file. There was a point.

An object of the present invention is to retain data used for restoring the FAT area even if index data in the FAT area is destroyed due to physical/logical factors such as hardware failure or software runaway. The goal is to provide a file control method that can

[Means to solve the problem]

The file control method of the present invention is a personal computer file format in which a data area consisting of code data, an in-file record management table area for managing index information of the data area, and information including a file name are stored. (A) a final record number extraction means for extracting the last record number of the file; (B) no record has been written to the corresponding data area and it is in an unused state; , empty record management table number extraction means for extracting a file record management table number in the in-file record management table area; (C) an unused file record management table number extracted by the empty record management table number extraction means; (D) data writing means for writing a new record in a data area; (D) writing the unused file record management table number for the last record before writing a new record in the data area indicated by the unused file record management table number; (E) In-file record management table number storage means for storing the unused file record management table number at the beginning of the record to which the unused file record management table number has been assigned. , and even if the in-file food management table area is destroyed, the in-file record management table area can be restored by referring to the in-file record management table data, which is the pointer at the beginning of each record that indicates the next record. It is configured to allow automatic data recovery.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

The file control method of the present invention includes a final record number extraction means for extracting the last record number of a file, and a file in an in-file record management table area that is unused because no record has been written to the corresponding data area. empty record management table number extraction means for extracting a record management table number; data writing means for writing a new record into a data area indicated by an unused file record management table number extracted by the empty record management table number extraction means; an in-file record management table number assigning means for assigning an unused file record management table number to the last record before writing a new record to the data area indicated by the unused file record management table number, and the unused file. It is comprised of in-file record management table number storage means for storing the unused file record management table number at the head of a record to which a record management table number has been assigned.

Next, the operation will be explained.

FIG. 1 shows the file structure of one embodiment of the present invention.
FIG. 1(a) shows a state in which records R1 to R5 have been written in file A, and FIG. 1(b) shows a state in which record R6 has been further written in file A.

The file shown in Figure 1 consists of a directory area that stores information such as file names, a FAT area that stores information for managing each record in the file, and a data area that is a collection of records. ing.

In Figure 1(a), the records in file A are NRI
~R5 is stored, but as in the case of FIG.
R5 is stored in the record storage area 14 corresponding to R5.
is stored in the record storage area 14 corresponding to FAT number 11 "8". In order to manage the above-mentioned records, the FAT area stores 12 FAT home office core record information, but the FAT number "7",
"FF" is stored in the location "8". This rF
FJ indicates that the record is the last record of file A to which the record belongs.

Then, before each record stored in the record storage area 14, FAT internal core record information is stored.
An internal core record information storage area 13 is provided, and FAT internal core record information corresponding to each record is stored here. However, FAT number r7J
, r8J are the last records of files A and B, respectively, so nothing is stored therein.

Now, suppose that Re (as a record of file A) is further written in the state shown in FIG. 1(a).

First, the last record number extracting means searches for a record to which "FF" is added in the FAT internal record information 12, and extracts the last record Rf5 of file A. Next, the empty record management table number extraction means extracts the FAT internal core record information 12 in the FAT area.
The location of the FAT number 11 that is not given is detected, and the data writing means writes R8 to the record storage area 14 of the data area corresponding to this FAT number "9" in FIG.
Write as shown in b). Then, by the in-file record management table number assigning means, R,!, which was the last record before writing R6, is used. "9" is assigned to the FAT internal core record information 12 of , and rFFJ is assigned to the FAT internal core record information 12 of the FAT number 11 in which R8 is written. In addition, record storage area 1 of R5
4 FAT internal information storage area 13, in-file record management table number storage means, R6
The FAT internal core record information 12 of "9" is stored.

In this way, by adding the FAT area recovery data to the beginning of the data record, even if the in-file record management table area is destroyed, the in-file pointer that is at the beginning of each record and indicates the next record can be saved. By referring to the record management table data, the data in the record management table area within the file can be automatically restored.

〔Effect of the invention〕

As explained above, the present invention adds FAT area recovery data to the beginning of a data record, thereby preventing data corruption in the FAT area due to physical/logical factors such as hardware failure or software runaway. Even in such a case, data for restoring the FAT area can be retained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the data file structure of the file control method of the present invention, and FIG. 2 is a diagram showing the data file structure of the conventional file control method. 11...FAT number, 12...FAT
Internal affairs record information 3... FAT internal affairs records information storage area 4... Record storage area. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Claims] As a file format for a personal computer, a data area consisting of code data, an in-file record management table area for managing index information of the data area,
In a file control method comprising: (A) a final record number extracting means for extracting the last record number of the file; (B) a record in the corresponding data area; an empty record management table number extracting means for extracting a file record management table number in the in-file record management table area which is not written and is in an unused state; (D) data writing means for writing a new record in the data area indicated by the unused file record management table number; (D) for the last record before writing a new record in the data area indicated by the unused file record management table number; (E) in-file record management table number assigning means for assigning the unused file record management table number to the beginning of the record to which the unused file record management table number has been assigned; An in-file record management table number storing means is provided, and even if the in-file record management table area is destroyed, the in-file record management table data, which is a pointer at the beginning of each record and indicating the next record, is referenced. A file control method characterized in that data in an in-file record management table area can be automatically restored by automatically restoring data in a record management table area within a file.