JPS63164087A - File management system - Google Patents

Abstract

PURPOSE:To shorten an access time for a file system that is often modified by providing a means to record an identification mark to identify the validity/ invalidity of a data stored in an information recording area, and executing the identification of a valid data. CONSTITUTION:In a direct-read-after-write type information recorder to record sequential information in an information recording medium, the means to record an identification mark to identify the validity/invalidity of a data recorded in an information storage area corresponding to the information recording area of the information recording medium is provided. Accordingly, the identification mark is such that one bit corresponds to a piece of data set including the object of processing and a processing, and a valid piece of it is represented by '1'. After the data is written for a determined number of sectors, one sector is read, whether it is a valid data or not is checked, if it is a valid data, an identification mark is made in '1' for it, but if it is invalid, the mark is made in '0'. After thus checking the data for the determined number of sectors, the identification marks are written. As a result, at the time of reading, selective readings in accordance with the validity/invalidity of the data can be executed, and the file access speed can be made maximal.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a file management system, and more particularly to a file management system that can shorten the access time of a file system that is frequently changed in a write-once information recording device such as an optical disk file.

Conventional technology For example, in conventional write-once optical disk file devices, the amount of recording increases when changes are made due to reasons such as not being able to be rewritten or the length of directory information that can be written at one time being fixed. There is a problem.

In write-once optical disk file devices having the above characteristics, a delete flag is usually set when certain data is deleted. However, since it is not possible to know whether the delete flag is set until the data is read, it is actually necessary to read the deleted data as well.

However, when the recorded contents are changed in large quantities, the amount of deleted data increases, resulting in a lot of unnecessary reading, which causes a problem in that the access speed decreases significantly.

Purpose The present invention has been made in view of the above circumstances, and its purpose is to solve the above-mentioned problems in conventional file management systems, and to write directory information in one go that cannot be rewritten as described above. The object of the present invention is to provide a file management method that can maximize access speed under constraints such as a fixed length.

Configuration The above-mentioned object of the present invention is to provide a write-once type information recording device that sequentially records information on an information recording medium, in which the information v! , a means for recording an identification mark to identify whether data recorded in the recording area is valid or invalid is provided, and upon access, the identification mark of the recording means is read out and analyzed, and only valid data is read out. This is achieved through a file management method.

Hereinafter, the configuration of the present invention will be explained in more detail based on examples.

Figure 2 is a diagram showing the format of the data set written to the optical disk, and the "processing target" indicates which data set it is for, and the "processing" includes ・addition (A) and deletion. There is (D).

For example, when data is written as "a" to "technique", it is recorded on the optical disk as shown in FIG.

Here, if the third data is changed to "o", the result will be as shown in FIG. In Figure 4, the fifth data set is blank, 2. DJ deletes the third data, and 2. AJ writes data "o" at that position. It is shown that.

Similarly, the third data is sequentially changed to "r force" and "ki".

. . . If the character is changed five times up to "ko", the result will be as shown in Fig. 5. However, this content is actually equivalent to that shown in FIG.

Therefore, an identification mark as shown in FIG. 7 is provided using a part of the recording area. This identification mark is 1
The bits correspond to one of the above-mentioned data sets, and valid bits are indicated by tl 1 j#. By referring to this identification mark and reading only the valid ones, here 1.2 and 4.16, it is possible to significantly shorten the access time.

How to record the above identification mark.

(1) A method of leaving a space at the beginning of the recording area in advance and writing there; (2) A method of writing data to a certain sector and then writing to the subsequent side. Further, the identification mark may be written when a certain number or more of data have been written, and thereafter, the identification mark may be written for each of that number.

After writing up to the above-mentioned certain number of sectors in FIG. 1(a),
A flowchart of the writing timing of the identification mark is shown, and a flowchart of the reading time is shown in FIG.

First, the operation shown in FIG. 1(a) is that after a certain number of sectors have been written, one sector is read (step 21), and it is checked whether or not it is valid data (step 22). Prepare to set the identification mark as "○N" (step 24), and if the data is not valid, perform a semi-ff& to set the identification mark as roFFJ (step 23), and complete all sectors of the fixed number of sectors. After the check is completed (step 25), an identification mark is written according to the results prepared in steps 23 and 24 (step 2).
6) It is a thing.

In addition, the reading operation shown in FIG. 1(b) is such that after starting reading the optical disc, the presence or absence of the identification mark is monitored (step 31), and if there is an identification mark, the reading operation is as shown in FIG. Validity of such data.

According to the invalid sra, only valid data is selectively read (step 32), and if there is no identification mark, all data is read as before (step 3).
3).

According to the above embodiment, by identifying valid data in a certain unit, it is possible to significantly shorten the access time for a file system that is frequently changed.

In the above embodiment, the validity/invalidity of data is checked for each unit and an identification mark is written.
After the second check, the identification mark includes the validity/invalidity of all data from the beginning. The second “
The size of each unit depends on the frequency of data changes, etc.
You can decide freely. Further, although not shown in the above embodiment, the identification mark may be written at the same time as the data change process.

Effects As described above, according to the present invention, in a write-once type information recording device that sequentially records information on an information recording medium, information is recorded in the information recording area corresponding to the information recording area of the information recording medium. A means for recording an identification mark to identify whether data is valid or invalid is provided, and when accessing, the identification mark of the recording means is read and analyzed to read only valid data, so the above-mentioned rewriting is not possible. This has the remarkable effect of realizing a file management system that can maximize access speed under constraints such as the length of directory information that can be written at one time.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are flowcharts showing the operation of an optical disk file device which is an embodiment of the present invention, FIG. 2 is a diagram showing the format of a data set written to an optical disk, and FIGS. FIG. 6 is a diagram showing an example of data written on an optical disk, and FIG. 7 is a diagram showing an example of an identification mark. 1-16: Data sets, 21-26. 31-33: Processing steps. Figure 1 (a) Figure 1 (b) Figure 2 Figure 3 Figure 2

Claims (1)

[Claims] (1) In a write-once information recording device that sequentially records information on an information recording medium, the validity of the data recorded in the information recording area of the information recording medium corresponds to the information recording area.
A file management system comprising means for recording an identification mark for identifying invalid data, and upon access, the identification mark of the recording means is read and analyzed to read only valid data.