JPH08123712A - File management system - Google Patents

Abstract

PURPOSE: To smoothly execute the operation of data blocks shared by plural files while effectively utilizing a storage medium. CONSTITUTION: Each of files A, B is constituted of a set of optional data blocks out of data blocks A0 , A1 ,... stored in a storage medium 41 and respective corresponding file management tables 31A, 31B manage respective files A, B. The file management table 31 stores the destinations of constituted data blocks stored in the medium 41 in a data block destination information storing area and stores the number of data blocks shared by the other file in a data block shared count value storing area 39. On the other hand, the destinations of the other similar table to be linked are stored in a file management table destination information storing area 35 and the number of shared data blocks is stored in a shared data block count value storing area 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file management system for managing a plurality of files created by a document processing apparatus such as a computer, and more specifically, copying a part of data constituting a file to a new file management system. The present invention relates to a file management system suitable for creating a file.

[0002]

2. Description of the Related Art A file created by a computer or the like may have completely independent constituent contents, but files associated with each other may be created. For example, it is assumed that a certain document file is created and another document file that is a partial revision thereof is newly created. In this case, it is often the case that a considerable part of the previous document file is copied or the content is partially corrected after copying. Therefore,
When managing related files, rather than storing them separately on a storage device, store the portion of the common part by clearly indicating that the contents are stored in one of the files. It has been conventionally practiced to reduce the total storage capacity by omitting.

FIG. 15 shows in principle the file management system proposed in Japanese Patent Laid-Open No. 63-27936. First to configure single or multiple files
Nth data block 11-1, 11-2, ..., 11
-N is composed of a data block body 12 and a reference counter storage area 13, respectively. A reference counter for managing the total number of files that commonly use each data block is stored in each reference counter storage area 13. For example, if the count value of the reference counter for the first data block 11-1 is "1", it is only used for one file. On the other hand, the second data block 1
If the count value of the reference counter 1-2 is “2”,
It means that they are jointly used as a data block that composes two files. The same applies hereinafter.

For example, a file A is composed of first, second and Mth data blocks 11-1, 11-2 and 11-M, and a file B is second, Mth and Nth data block 11 respectively. -2, 11-M, 11-N, and if no other file exists, the above-mentioned count value is taken. A file management table 1 corresponding to each of the files A and B
4A and 14B are prepared, and pointer information indicating at which address in the storage device each data block forming the file is stored is stored in these. For example, in the file A, the first and the second which compose it are
And the Mth data blocks 11-1, 11-2, 11
The pointer information 15-1, 15-2, and 15-M of -M are stored in order.

In the proposed file management system, when a new file is created, the corresponding file management table 14 is created and the pointer information 15 is written in each file.

FIG. 16 shows the principle of a file management system using a virtual copy file proposed in Japanese Patent Laid-Open No. 2-257340. Here, the first
~ Nth data block 21-1, 21-2, ... 21
-N is prepared, and the file management table 22A corresponding to the file A is prepared primitively.
In the file management table 22A, pointer information 15-
1, 15-2, 15-M are stored in the first, second and Mth data blocks 21-1, respectively.
21-2, 21-M are used.

According to this proposal, when the file B related to the file A is created, the file management table 22A of the file A is copied. And data block 1
5, a virtual copy file identification code 23A indicating that the data block 15 has been copied to both file management tables 22A and 22B to indicate that 5 has been copied.
Add 23B. Assuming that the file B is composed of the Mth, second and Nth data blocks 21-M, 21-2, 21-N as in the previous proposal shown in FIG. 15, the file management table 22B stores Is the second M
And Nth pointer information 15-M, 15-2, 15-
N is stored in this order.

In this latter proposal, the file B is modified. In this case, the virtual copy file identification code 23B is checked, and if this indicates a virtual copy file, there is a possibility that the same data block exists in the original file A, and this can be arbitrarily corrected. Can not. Therefore, in this case, the file management table 22A of the original file A is checked to see if the data block 21 to be corrected exists. When it exists, the data block 21 is newly acquired and the data block 21 is corrected. Along with this, file B
That is, the pointer information 15 of the corresponding data block in the file management table 22B is changed to the pointer information indicating the newly acquired data block 21.

[0009]

Among these, in the file management system proposed by the former, each data block 11-
1, 11-2, ... 11-N is the data block body 12
And the reference counter storage area 13. That is, it is necessary to add the reference counter storage area 13 in addition to the data block body 12 as the content of data. The data block body 12 is normally set in page units (usually 512 byte units) in consideration of the efficiency of data transfer by a computer or the like. Therefore, the reference counter storage area 13 externally added to this also has one page removed. Allocating such a relatively large capacity storage area only for storing the count value of the reference counter in each of the data blocks 11-1, 11-2, ... 11-N promotes effective use of the memory. Not possible, and each data block 11-1, 1
There is also a problem that it becomes inefficient when transferring 1-2, ... 11-N.

On the other hand, in the latter file management system,
When a file is modified, the virtual copy file identification code 23 of the file is checked, and if this indicates a virtual copy file, the file management table 22 of the original file is searched and the same data block 21 exists. You need to check if. That is,
Once the virtual copy file identification code 23 is added, the file management table 2 of the copy source file is changed every time the file is changed until the file is deleted.
It is necessary to search 2 and work efficiency is poor. Further, when the modified virtual copy file is further copied, the relationship between the new copy destination and the copy source can be associated with this virtual copy file identification code 23, but the file management table 22 of the first file There is a problem that you can't get to and can't refer to it.

SUMMARY OF THE INVENTION An object of the present invention is to provide a file management system capable of smoothly operating a data block shared by a plurality of files while effectively utilizing a storage medium.

[0012]

According to a first aspect of the present invention, there is provided (a) a storage medium such as a magnetic disk, an optical disk, a magnetic tape, or a semiconductor memory for storing respective data blocks as a data portion constituting a file. ,
(B) Stores area information that specifies the storage area on the storage medium for each of the data blocks that are prepared for each file and that compose them, and shared information that indicates the shared relationship between those data blocks and other files. Change the contents of the shared file management table and the contents of the file management table of the file according to the processing of the file (c) and the file management table of the file having the same data block as the processed data block of the file. The file management system is provided with a file management table content changing means for changing the contents according to the above.

That is, according to the first aspect of the invention, each data block as a data portion forming a file is stored in the storage medium, and the file management table is set for each file. The file management table stores area information that specifies where on the storage medium each data block making up a file is stored, and shared information that represents the sharing relationship between these data blocks and other files. It has become so. When a file is copied or the contents are changed, the contents of its own file management table are changed, and the contents of the file management table of other files in a shared relationship also change. I am going to change it accordingly. In such a file management system, since each data block itself does not have additional information indicating a sharing relationship or the like, the storage medium can be effectively used. In addition, since the sharing relationship is shown in the file management table of each file, the data block shared by a plurality of files can be smoothly operated based on this.

According to the second aspect of the invention, (a) a magnetic disk, an optical disk, a magnetic tape for storing each data block as a data portion forming a file,
A storage medium such as a semiconductor memory, and (b) area information that specifies a storage area on the storage medium for each of the data blocks that are prepared for each file and that compose them, and the sharing of those data blocks with other files. The presence / absence and sharing information indicating the number of other shared files when shared, and link information for linking with the file when there is a file copy relationship with other files are stored. File management table, and (c) the file management table of the file according to the processing of the file, and the contents of the file management table of the file having the same data block as the processed data block of the file using the link information. File management table contents change procedure to search and change these according to the change of sharing relationship It is provided with a door in the file management system.

That is, according to the second aspect of the invention, each data block as a data portion forming a file is stored on the storage medium, and the file management table is set for each file. In the file management table, together with area information that specifies where on the storage medium each data block making up a file is stored, whether these data blocks are shared with other files and when they are shared Stores shared information indicating the number of other files shared, and link information for linking with other files when there is a file copy relationship with other files. Therefore, since the data block itself does not have additional information indicating the sharing relationship or the like, the storage medium can be effectively used. In addition, when a file is copied or the contents are changed, not only can the sharing status be checked in data block units, but there is a sharing relationship or a data copy relationship in file management table units. Whether or not the file management table of the file exists can be determined using the file management table, so that the operation of the data block shared by a plurality of files can be smoothly performed.

According to a third aspect of the invention, (a) a magnetic disk, an optical disk, a magnetic tape for storing each data block as a data portion forming a file,
A storage medium such as a semiconductor memory, and (b) area information that specifies a storage area on the storage medium for each of the data blocks that are prepared for each file and that compose them, and the sharing of those data blocks with other files. Share information and other files that indicate the presence or absence and, if shared, the number of other files shared and the total number of other files shared for each data block that composes its own file. File management table that stores link information for linking with the file when there is a file and file copy relationship, and (c) When copying a file, the contents of each data block of the file management table of the file And link information between the file management tables of these files. A file management table contents changing means at the time of copying for resetting the sharing information of these file management tables and all the file management tables linked to them and having a sharing relationship in the data block depending on the occurrence of the block sharing relationship, ( D) When changing the contents of a file, check the shared information to see if the data block that changes the contents of the file has a shared relationship with another file. If it does not have a shared relationship, the contents of that data block Process on the storage medium, the process is terminated, and if there is a shared relationship, the changed contents of the data block are newly stored in another area on this storage medium, and While changing the area information that specifies the storage area for the data block to the information that specifies the changed data block, A file management table content changing means at the time of data block content change for resetting shared information of another file management table having a data block having a shared relationship with its own file management table and its data block (E) When deleting a file, check whether the total number of shared information in the file management table of the file to be deleted is zero, and if it is zero, store all data blocks of the file to be deleted. The file management table of the file is deleted by releasing it from the medium, and if it is not zero, the file management table of another file that has a shared relationship with each data block that constitutes the file to be deleted is searched from the link information and shared. It is linked to the file management table of the file to be resolved and deleted. The shared information and the link information are reset when the link relationship of the file management table is canceled, and the data blocks forming the file to be deleted that are not in a shared relationship with the data blocks of other files are released from the storage medium. Then, the file management system is provided with a file management table processing means at the time of file deletion for deleting the file management table of the file.

That is, according to the third aspect of the invention, each data block as a data portion constituting a file is stored on the storage medium, and the file management table is set for each file. In the file management table, together with area information that specifies where on the storage medium each data block making up a file is stored, whether these data blocks are shared with other files and when they are shared Stores shared information indicating the number of other files shared, and link information for linking with other files when there is a file copy relationship with other files. Further, in accordance with the processing contents of the file, the file management table contents changing means for changing the contents of the file management table when copying the file and the contents of the file management table when the contents of the data block are changed The file management table contents changing means for changing the contents of the data block and the file management table processing means for deleting the files for processing the file management table when deleting the files are provided, so that various file operations can be performed smoothly. It can be carried out.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

FIG. 1 shows the relationship between the file management table and the data block on the storage medium for file A which does not have a data block shared by other files. The file management table 31A includes a header information storage area 32 and _0th to 4th data block management array areas 33 _{0 to} 3 3 corresponding to respective data blocks.
It is composed of 3 ₄ . This is because the file A of this embodiment is composed of a total of 5 data blocks. For example, if the file A is composed of a total of 4 data blocks, the 0th to 3rd data block management array areas 33 _{0 to} 33 ₃ .

FIG. 2 shows the structure of the header information storage area. The header information storage area 32 includes a file management table destination information storage area 35, a shared data block count value storage area 36, and another information storage area 37.
It consists of Here, the file management table destination information storage area 35 is the destination information (pointer) of the file management table of the file sharing the data block.
Is an area for storing. If the shared data block does not exist, "0" is stored, and if it exists, the address on the storage medium is stored.
In the example shown in FIG. 1, since the file A does not have a data block having a shared relationship with other files, "0" is stored.

Shared data block count value storage area 3
An area 6 stores the total number of data blocks shared with other files. Zeroth fourth data block management arrangement region 33 _{0-33 4} shown in FIG. 1, when the identification information indicates that they share some data blocks, the total number of shared data block count value It will be stored in the storage area 36. In the example shown in FIG. 1, since the file A does not have a data block having a shared relationship with other files, “0” is also stored here as the count value.

FIG. 3 shows the structure of each data block management array area. The data block management array area 33 is the data block destination information storage area 3
8 and a data block shared count value storage area 39. Here, the data block destination information storage area 38 is an area for storing the destination information (pointer) of the corresponding data block on the storage medium. For example, in FIG. 1, in the 0th data block management array area 33 ₀ ,
The destination information “a ₀ ” is stored, which indicates the destination information (address) on the storage medium 41 that stores the data block. From here, for example, a data block A ₀ is stored in an area of 512 bytes,
This is designated in the 0th data block management array area 33 ₀ .

In FIG. 3, the data block shared count value storage area 39 shows a value in which the data block is shared with another file. When the data block is not shared as shown in FIG. 1, the count value is not shared. Will be stored as "0". In the file management table 31A of the file A shown in FIG. 1, the data block A ₀ specified by the _{0th to 4th} data block management array areas 33 _{0 to} 334.
Since to A ₄ are not both shared with other file, these data blocks share count value storage area 39 are both at "0", the value of the shared data block count value storage area 36 as their sum (See FIG. 2) is also “0”. As described above, in the file management system of the present embodiment, if the shared data block count value storage area 36 in the header information storage area 32 is checked, other files and data blocks can be checked without checking the file management table 31 of other files. It is possible to determine whether or not they are sharing. Therefore, the operation is simplified for a file that does not share a data block with another file (hereinafter referred to as a normal file).

FIG. 4 shows the relationship between the file management table and the data blocks of the file B obtained by copying the file A. When creating a file B that shares a data block with the file A, the corresponding data block management array area 33 _{0 in} the file management table 31A of the file A is created without newly creating the data blocks that make up each file. Copy only 33 ₄ . The data block shared count value storage area 39 of each of the file management tables 31A and 31B is stored.
Since the data block is shared, “0” is changed to “1”. In addition, the file management table 31
In the shared data block count value storage area 36 in the header information storage area 32 of A, “5” is stored as the total value of the shared data blocks. The same applies to the shared data block count value storage area 36 of the file management table 31B.

Further, it is assumed that the file management table 31A stores the destination information f _A on the storage medium as the head address, and the file management table 31B stores the destination information f _B on the storage medium as the head address. Then, the destination information f _B is stored in the file management table destination information storage area 35 in the header information storage area 32 of the file management table 31A. Further, the destination information f _A is stored in the file management table destination information storage area 35 in the header information storage area 32 of the file management table 31B.

FIG. 5 shows an example when the file B is changed. The file B described in FIG. 4 is a copy of the file A, and the file A
Is the same in content. Actually, by modifying this, the target file will be created. Figure 5
In the example shown in (4), the fourth data block management array area 33 ₄ of the file B is changed to the data block B ₄ . The destination information on the storage medium 41 is
Along with this has been changed from _{"a 4""b4"} .
Further, since the data block A ₄ is no longer in the sharing relationship, the count value of the data block shared count value storage area 39 of the fourth data block management array area 33 ₄ of the file management table 31A is “0”. If the data block B ₄ is newly created, it has no shared relationship with other files at this time, so the data block sharing count of the fourth data block management array area 33 ₄ of the file management table 31B. Similarly, the count value of the value storage area 39 becomes "0". Also, along with these changes, the file management tables 31
The value of the shared data block count value storage area 36 in the header information storage areas 32 of A and 31B is "4".

FIG. 6 shows the file A as explained in FIG.
And the relationship between the file management table and the data block for file B when file A is deleted under the condition that file B exists. File B
Since the count value of each data block management arrangement region 33 _{0-33 4} data blocks share count value storage area 39 of no longer sharing relationship, all "0". The value of the shared data block count value storage area 36 in the header information storage area 32 changes from "4" to "0". This indicates that the data block is not shared with other files. The file management table destination information storage area 35 will also be changed to "0" because there is no other file management table 31 sharing the data block.

FIG. 7 shows the configuration of the main part of an information processing apparatus such as a computer that realizes the file management system of this embodiment. This information processing device is a CPU (central processing unit) that performs a central function for performing various controls.
It is equipped with 51. The CPU 51 is connected to each unit in the device via a bus 52 such as a data bus. Of these, the work memory 53 is a random access memory that temporarily stores data and programs required for various controls. The file management table 31 for each file in this embodiment is also arranged in this work memory 53 during work. The disk controller 54 uses the magnetic disk 5
5 is an apparatus for controlling input / output. The magnetic disk 55 stores the various programs described above, and also stores various files and a file management table 31.

The input circuit 56 is a circuit for inputting data, and in the present embodiment, a keyboard 58 to which a mouse 57 as a pointing device is connected is connected to this. The display control circuit 51 is used to display visual data on the CRT 61. CRT61
Besides, other displays such as a liquid crystal display may be used. The print control circuit 62 is a circuit for performing control when the printer 63 prints various data such as created files. The communication control circuit 64 performs communication control for receiving a file created by another similar information processing apparatus via the communication cable 65 and for transmitting the created file. A file created by another device may be input from another input device such as a floppy disk or magnetic tape (not shown).

FIG. 8 corresponds to FIG. 4 and shows the control contents when a file copy operation is performed. When the operator specifies a file and gives an instruction to copy the file (step S101; Y), the CPU 51 creates the format of the file management table of the copy destination and copies the corresponding data block management array area 33 of the copy source to this ( Step S102). Next, the data block shared count value storage areas 39 of all linked file management tables 31 are each incremented by "1" (step S103). That is, in the example shown in FIG. 4, since the file A is a normal file, the count value “0” is incremented to “1” for each of the copy source and copy destination data blocks, and the copy destination data block is shared. The count value storage area 39 is also set to "1". This is the case when two files are linked.

FIG. 9 shows the case where the file A is copied to create the file B, and the file B is further copied to create the file C, that is, the case where three files are linked. Here, considering the case where the file C is copied from the file B, the data block shared count value storage areas 39 of all the linked file management tables 31 are counted up by "1" (step S102). Files A, B,
The data block shared count value storage area 39 for all the file management tables 31 of C is incremented by "1". Also in the case where the file B and the file C are separately copied from the file A as shown in FIG. 10, the data block shared count value storage areas 39 of the files A, B, and C that are similarly linked are respectively stored. Only "1" will be counted up. 9 and 10 show the case where three files are linked, the same process can be performed when four or more files are linked.

In the next step S104, as the count value of the data block shared count value storage area 39 of each file management table 31 is changed,
The count value of the shared data block count value storage area 36 is changed to the total value of the count values of the data block shared count value storage area 39 for each file (file management table 31 of all linked files).

In the final step S105, the destination information is stored in the file management table destination information storage area 35 of the corresponding file management table 31. The destination information may be changed. For example, in the case of the link relationship shown in FIG. 9, when the file B is copied from the file A, the respective file management tables 31A and 31B
The destination information stored in the destination information storage area 35 of the file management table is as shown in FIG. File B
When the file C is copied from, the destination information f _C of the file management table 31C of the file _C is added to the file management table destination information storage area 35 of the file B. Further, the destination information f _B of the file management table 31B of the file _B is stored in the file management table destination information storage area 35 of the file C. In this way, the destination information f _A and f _C indicating the file management tables 31A and 31B of the files in the respective branch directions are stored in the file management table destination information storage area 35 of the file B branched in both directions. become. The same applies when the branch is made in three directions or more, and these relationships are stored.

In the example shown in FIG. 10, file A is copied from file B, and file A is copied from file C. Thus, the file management table the destination information storage area 35 in the file management table 31A of the file A, so that the file management table 31B of the respective branch direction file, address information f _B indicating a 31C, f _C is stored . At this time, the destination information f _A is stored in both the file management table destination information storage areas 35 of the files B and C.

FIG. 11 corresponds to FIG. 5 and shows the control contents when the file is changed.
When the operator intends to change a data block in a certain file (step S201; Y), the corresponding data block management array area 33 is accessed (step S202) and the data block shared count value storage area 39 It is checked whether the count value is "0" (step S203). If the count value is "0", the data block is not shared with other files. Therefore, it is ok to change the content. Therefore, the destination information about the data block written in the data block destination information storage area 38 is obtained (step S204), and the content of the data block is changed to the desired one (step S20).
5). After that, the CPU 51 checks whether the processing of the data block (the same data block or another data block) is completed (step S206), and if not completed, the process returns to step S202 and the same data block is processed. Perform processing. When the processing is completed (step S206; Y), the work for the data block change processing is completed (END).

If the count value of the data block shared count value storage area 39 of the corresponding data block is other than "0" in step S203 (N), the contents of the data block cannot be processed arbitrarily. . Therefore, the procedure for sharing the data block is executed (step S207). This will be described next.

FIG. 12 shows concretely the processing when the data block shown in step S207 of FIG. 11 is shared. First, the CPU 51 reads the data block destination information storage area 38 and acquires the destination information about the data block to be processed (step S
301), and subsequently, the destination information of the file management table 31 is acquired from the file management table destination information storage area 35 in the header information storage area 32 (step S30).
2). Then, the file management table 31 of the link destination stored in the location indicated by the destination information is searched, and the count value of the data block shared count value storage area 39 of the corresponding data block and the shared data block count value storage area 36. The count value of each is subtracted by "1" (step S303). This is because, since the sharing relationship of the corresponding data block disappears, the corresponding two count values for the file management table 31 of the other party are subtracted by "1". In the example shown in FIG. 5, in comparison with FIG. 4, the file management table 31
The count value of the header information of A and the count value of the corresponding data block are each decremented by "1".

After that, the contents of the data block are changed or created (step S304). If this data block modifies the previous data block (step S305; Y), the data block is acquired on the storage medium 41 separately from the previous data block. Then, the corrected contents are stored in this. In the example shown in FIG. 5, the data block B ₄ is created, and its contents are stored here. Further, the destination information indicating the data block B ₄ is stored in the data block destination information storage area 38 of the fourth data block management array area 33 ₄ of the corresponding file management table 31B, and the data block shared count value storage area 39 is stored. The count value is set to "0" (step S306). After that, the count value of the shared data block count value storage area 36 of the own file management table 31B is decremented by "1" (step S307). This means that the count value in the data block shared count value storage area 39 is set to "1" in step S306.
This is due to the subtraction.

On the other hand, if the created data block is not adopted in step S305 (N),
Since the data block is excluded from the corresponding file, the corresponding data block management array area 33 is cleared (step S308). In the example shown in FIG. 5, when the created data block B ₄ is not used for the file B, the fourth data block management array area 3
You will clear 3 ₄ .

In the description of FIG. 12, the description when three or more file management tables 31 are linked is omitted. In such a case, each file management table 31
The file management table destination information storage area 35 in the header information storage area 32 is set to the link shape as described above. Therefore, by using this, it is possible to trace back to the link destination in order, correct the count value of the corresponding data block shared count value storage area 39, and change the information stored in these header information storage areas 32.

FIG. 13 shows the flow of processing when deleting a file. When a file is specified and its deletion is instructed (step S401; Y),
The count value of the shared data block count value storage area 36 of the file is read (step S40).
2). When this is "0", it means that all the data blocks forming the file to be deleted are not shared by other files (step S403; Y).
That is, this file is a regular file. In this case, by deleting these data blocks from the storage medium 41 (step S404) and deleting the file management table 31 of the file (step S405), the file is substantially deleted.

If the count value of the shared data block count value storage area 36 is not "0" in step S402 (N), it is deleted from all the file management tables 31 linked to the file management table 31 of the file to be deleted. The count value corresponding to each data block of the file to be processed is associated and subtracted (step S406). And step S4
In step 04, only the data block unique to the file is deleted from the data blocks of the file to be deleted. This is the data block shared count value storage area 39.
It is realized by releasing only the data block whose count value is “0” from the storage medium 41.
After this, the file management table 31 of the file to be deleted
Is deleted and the process ends (end).

FIG. 14 partially embodies the processing contents of the linked file management table shown in step S406 of FIG. First, the variable n stored in a predetermined area of the work memory 53 (FIG. 7) is set to "1" (step S501), and the file management table destination information storage area 35 of the file management table 31 of the file to be deleted is set. The contents of the first (n = 1) file management table 31 of the file directly linked to the file to be deleted indicated by the stored destination information are read (step S502). Then, this is collated with the file management table 31 of the file to be deleted, and if there is a data block common to both,
The count values in the data block shared count value storage area 39 are respectively subtracted by "1", and the count values in the shared data block count value storage area 36 of the file management tables 31 and 31 of these pairs are similarly subtracted. (Step S503).

After that, the variable n is incremented by "1" (step S504), and whether the count value of the shared data block count value storage area 36 of the file management table 31 of the file to be deleted is decremented to "0". It is determined (step S505). This is because if the count value becomes "0" in the processing of step S503, the file to be deleted has a shared relationship with other files at this point, and therefore the subsequent processing is required. Because there is no. Therefore, if this count value becomes "0" (step S505; Y), the process ends at this point (end).

In other cases (step S505;
N), it is checked whether processing of all tables of files directly linked to the file to be deleted is completed (step S506), and when processing of the updated nth file management table exists (N), Step S
Proceeding to 502, similar processing is performed. In this way, when the processing of all the tables of the files directly linked to the files to be deleted is completed (step S506; Y),
The same processing as described in step S503 is performed for other file management tables linked via these directly linked files (step S507).
In this way, when the adjustment of all the file management tables 31 that share the same data block as each data block of the file to be deleted is completed, the processes of steps S404 and S405 of FIG. 13 are performed to specify the specified file. Will be substantially completed.

In the above-described embodiment, the description has been made on the premise that each data block of the file is composed of an equal data amount of 512 bytes, for example. Of course, the data amount of each data block may have different values or different ratios. When the data amount of the data block differs depending on the file management table 31, it is sufficient to store the information related to this in the other information storage area 37 shown in FIG. 2, for example.

Further, in the embodiment, the storage medium in which the data blocks are stored is shown in the figure as an area having continuous addresses, but the present invention is not limited to this, and the area may be divided or a plurality of storage media may be provided. In addition, these storage areas may be straddled. The same applies to the area in which the file management table is stored.

[0048]

As described above, according to the first aspect of the invention, each data block as a data portion forming a file is stored on the storage medium, and the file management table is set for each file. I am trying. Since such data block itself does not have additional information indicating a sharing relationship or the like, the storage medium can be effectively used. In addition, in the file management table, together with area information that specifies where on the storage medium the respective data blocks that make up the file are stored,
Shared information indicating a shared relationship between these data blocks and other files is stored. Therefore, when the file management table of another file is changed when the file is copied or the contents are changed, the operation of the data block shared by a plurality of files is smoothly performed by using the shared information. be able to.

According to the second aspect of the invention, each data block as a data portion forming a file is stored on the storage medium, and the file management table is set for each file. Since such data block itself does not have additional information indicating a sharing relationship or the like, the storage medium can be effectively used. In addition, in the file management table, together with area information that specifies where on the storage medium each data block making up a file is stored, whether these data blocks and other files are shared and shared. In this case, shared information indicating the number of other shared files and link information for linking with other files when the file has a copy relationship with other files are stored. Therefore, when a file is copied or the contents are changed, not only can the sharing status be checked in data block units, but there is also a sharing relationship between data blocks in file management table units, or other copy relationships. Whether or not the file management table of the file exists can be determined using the file management table, so that the operation of the data block shared by a plurality of files can be smoothly performed.

Further, according to the invention of claim 3, the same effect as that of the invention of claim 2 can be obtained, and the contents of the file management table at the time of copying the file are changed according to the processing contents of the file. File management table contents changing means for copying, file management table contents changing means for changing data block contents when changing data block contents, and file management table when deleting files Since the file management table processing means at the time of file deletion for performing the above processing is provided, various operations of the file can be smoothly performed by using the shared information and link information shown in the file management table of the self or related files. it can.

For example, when changing the contents of a data block, the means for changing the contents of the file management table is such that the data block to be changed is not in a shared relationship with the data blocks of other files in the shared information shown in the file management table of its own file If it is determined, the change process can be immediately performed without referring to the file management tables of other files. Further, the file deletion table management means for deleting a file checks whether or not the total number of sharing of each data block in the sharing information of the file management table of the file to be deleted is zero, If it is zero, it is clear that there is no shared relationship with the data block of any file. Therefore, it is possible to release all the data blocks of the file to be deleted from the storage medium and delete the file management table of that file. Files can be deleted.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a relationship between a file management table for a normal file A and a data block on a storage medium in a file management system of this embodiment.

FIG. 2 is an explanatory diagram showing the configuration of a header information storage area of the file management table of this embodiment.

FIG. 3 is an explanatory diagram showing the configuration of each data block management array area of the file management table of this embodiment.

FIG. 4 is an explanatory diagram showing a relationship between a file management table and a data block of a file B obtained by copying the file A in the present embodiment.

FIG. 5 is an explanatory diagram showing an example of a case where a file B after copying is changed in this embodiment.

FIG. 6 is an explanatory diagram showing a relationship between a file management table and a data block for a file B when one of the linked files A is deleted in the present embodiment.

FIG. 7 is a block diagram showing a configuration of a main part of an information processing apparatus such as a computer that realizes the file management system of this embodiment.

FIG. 8 is a flowchart showing the control contents when a file copy operation is performed in this embodiment.

FIG. 9 is an explanatory diagram showing a case where file A is copied to create file B, and this file B is further copied to create file C.

FIG. 10 is an explanatory diagram showing a case where a file A is copied and a file B and a file C are created separately.

FIG. 11 is a flowchart showing the control contents when a file is changed in this embodiment.

FIG. 12 is a flowchart specifically showing the processing when the data block shown in step S207 of FIG. 11 is shared.

FIG. 13 is a flowchart showing the flow of processing when deleting a file in this embodiment.

FIG. 14 is a flowchart partially embodying the processing contents of the linked file management table shown in step S406 of FIG.

FIG. 15 is one of the conventionally proposed file management systems.
It is the block diagram which showed the one in principle.

FIG. 16 is a block diagram showing the principle of another conventionally proposed file management system.

[Explanation of symbols]

31 ... File management table, 32 ... Header information storage area, 33 ... Data block management array area, 35 ... File management table destination information storage area, 36 ... Shared data block count value storage area, 38 ... Data block destination information storage area, 39 ... Data block shared count value storage area, 41 ... Storage medium, 51 ... CPU, 53 ... Working memory, 55 ... Magnetic disk, 58 ... Keyboard, 59
… Mouse, A, B… Data block

Claims (3)

[Claims] 1. A storage medium for storing each data block as a data portion forming a file, and an area for specifying a storage area on the storage medium for each of the data blocks prepared for each file and forming the files. A file management table that stores information and the shared information that indicates the sharing relationship between those data blocks and other files, the file management table for that file according to the processing of the file, and the data block that is processed for that file And a file management table content changing means for changing the contents of the file management table of a file having the same data block as the sharing relationship. 2. A storage medium for storing each data block as a data portion constituting a file, and a region for specifying a storage region on the storage medium for each of the data blocks prepared for each file and constituting them. Shared information that indicates whether information, those data blocks, and other files are shared and, if shared, the number of other files that are shared, and when there is a file copy relationship with other files A file management table storing link information for linking with the file, a file management table for the file according to the processing of the file, and the same data block as the processed data block of the file using the link information. Search and share the contents of the file management table for files with data blocks File management system characterized by comprising a file management table changing means for changing them in accordance with the change of the engagement. 3. A storage medium for storing each data block as a data portion constituting a file, and an area for specifying a storage area on the storage medium for each of the data blocks prepared for each file and constituting them. Information, whether or not those data blocks are shared with other files, and if shared, the number of other files that are shared and other shared information about each data block that makes up your file. A file management table that stores shared information that indicates the total number of files, and link information for linking with other files when there is a file copy relationship with other files, and when copying files Copy the contents of each data block of the file management table of the file The link information is set between the file management tables of the files, and the shared information of these file management tables and all the file management tables linked with them and having a shared relationship in the data block according to the occurrence of the shared relationship of the data blocks. The file management table contents changing means at the time of copying for resetting the file, and when changing the contents of the file, the shared information is checked to see if the data block that changes the contents of the file has a shared relationship with other files. When the data block is not in the sharing relationship, the processing is ended by merely changing the content of the data block on the storage medium, and when the data block is in the sharing relationship, the data block is changed to another area on the storage medium. Content is newly stored and the storage area for that data block in its own file management table is specified. Change the shared area information to the information that identifies the changed data block, and resolve the shared information of the shared information of its own file management table and other file management tables that have data blocks that have a shared relationship with that data block. The file management table contents changing means when changing the contents of the data block, and when deleting the file, check whether the total number in the shared information of the file management table of the file to be deleted is zero. , If it is zero, all the data blocks of the file to be deleted are released from the storage medium and the file management table of the file is deleted, and if it is not zero, each data block forming the file to be deleted is shared with each other. Search the file management table of other files in Resolving the relationship and resetting the link information of the file management table linked to the file management table of the file to be deleted, the shared information and the link information are reset, and other files in the data blocks that compose the file to be deleted File management table processing means for releasing a file management table of the file by releasing those not having a shared relationship with the data block from the storage medium.