JP2844885B2 - Library type file directory extension method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a directory extension method for library-type files.

[Conventional technology]

Conventionally, description information of a sub file, which is a data group of a library type file, is stored in one of directory blocks obtained by dividing a directory area into a plurality.

The storage method is randomly determined by the hash (HASH) method based on the subfile name and the number of directory blocks.
Direct access was possible. When the directory block storing the sub-file description information is full of the sub-file description information, it is stored in the directory overflow area.

The subfile description information stored in the directory overflow area is stored in order from the top of the directory overflow area.

[Problems to be solved by the invention]

 The conventional technique described above has the following problems.

When a subfile having subfile description information is accessed in the directory overflow area, the overflow area 26 must be searched in order from the beginning in the search for the subfile description information, and there is a disadvantage that access efficiency is poor.

In addition, simply expanding the directory area has the disadvantage that the entire directory area needs to be reconfigured because the number of directory blocks changes and the hashing method changes when accessing the sub-file description information.

[Means for solving the problem]

According to a first directory extension method of a library type file of the present invention, a directory area storing a plurality of directory blocks including sub-file description information of a sub-file which is a data group having the same attribute is provided. An extended directory area capable of storing a plurality of directory blocks including sub-file description information of the sub-file, an overflow directory area capable of storing at least one of the sub-file description information, and data of a plurality of sub-files In a library type file including a data area for storing a group, when the sub-file is created, the sub-file is created using a hash method based on a sub-file name of the sub-file and the number of directory blocks in the directory area. No A directory block in the directory area for storing the file description information is determined, and it is determined whether the sub-file description information of the sub-file can be stored in the directory block. Determining whether the extension directory area exists in the library file;
If it is determined that the file exists, the extension for storing the subfile description information of the subfile using a hash method based on the subfile name of the subfile and the number of directory blocks in the extension directory area is used. Directory block checking means for determining a directory block in a directory area and determining whether sub-file description information of the sub-file can be stored in the directory block; and If it is determined that the description information can be stored in a directory block in the directory area, the sub file description information of the sub file is stored in a directory block in the directory area, and the sub file description of the sub file is stored. Emotion Is stored in the directory block in the extended directory area, the sub-file description information of the sub-file is stored in the directory block in the extended directory area, and the sub-file description of the sub file is stored. When it is determined that the information cannot be stored in the directory block in the extended directory area, the sub-file description information registering means for storing the sub-file description information of the sub-file in the overflow area is provided. Features.

According to a second library-type file directory extension method of the present invention, in the first library-type file directory extension method, it is determined whether or not the extension directory area can be created in the library file, and it is determined that the extension directory area can be created. In this case, there is provided a directory area extension means for creating the extension directory area in the library file, and the directory block check means, when it is determined that the extension directory area does not exist in the library file, The extension directory area is created in the library file by directory area extension means, and the sub-file is created using a hash method based on the sub-file name of the sub-file and the number of directory blocks in the created extension directory area. Determining the directory block of the extension directory region for storing the sub-file description information, the sub-file description information registration means,
When the directory block checking means determines to store the sub-file information of the sub-file in a directory block in the extension directory created by the directory area expanding means, the sub-file description information of the sub-file is It is stored in a directory block in the extended directory area.

According to a third library-type file directory extension method of the present invention, in the second library-type file directory extension method, when the sub-file is referred to, a sub-file name of the sub-file and a directory block in the directory area are referred to. When the directory block in the directory area is specified by using the hash method based on the number and the sub-block description information of the sub-file is stored in the directory block, and it is determined that the sub-file description information is not stored in the directory block. Specifies a directory block in the extended directory area using a hash method based on a subfile name of the subfile and the number of directory blocks in the extended directory area, and stores the subfile in the directory block. Subfile description information is Directory block retrieving means for judging whether or not the sub-file is stored, and when the directory block retrieving means determines that the sub-file description information of the sub-file is stored in a directory block in the directory area, The sub-file description information of the sub-file is read, and if it is determined that the sub-file description information of the sub-file is stored in a directory block in the extended directory area, the sub-file of the sub-file is read from the directory block. Subfile description information searching means for reading description information.

〔Example〕

 The present invention will be described in detail with reference to the drawings.

1 and 2 are block diagrams showing the configuration of an embodiment of the present invention, and FIG. 3 is a flowchart showing the processing of the directory extension means of FIG.

With reference to FIG. 2, a library type file used in this embodiment will be described.

The library type file 7 includes subfile description information 23 of a subfile forming a data group having the same attribute, a directory area 22 for storing the subfile description information 23, and subdirectory description information A directory block 24 in which 23 is stored; a directory overflow area 26 in which the directory block 24 overflows and the sub-file description information 24 is stored when the extended directory area 28 cannot be secured;
A data area 27 for storing data of the subfile, a data management block area (hereinafter referred to as "BAM area") 25 for managing the data area 27 of the file, and an extended directory that is extended when the directory block 24 overflows And a library type file 7 composed of an area 28.

Next, the present embodiment configured as described above will be described with reference to FIGS.

To create a new subfile of library type file 7,
This is performed by registering the sub file description information 23 of the sub file in the directory block 24 which is the directory area 22. The sub file is referred to by the sub file description information 23 registered in the directory block 24.
It is possible by finding. This subfile description information
In the registration of 23, since the registration is to the directory block 24 having a finite size, the directory block 24
You may not be able to register.

In this embodiment, a registration method and a search method when registration in the directory block 24 is not possible will be described.

The directory block 24 determined at random by the hash method based on the number of directory blocks 23 and the subfile name in which the subfile description information 23 is referred to from the file description information 21 on the directory can be registered in the directory block 23. When it is determined by the directory block checking means 1 that it cannot be stored, whether or not the secondary directory area, which is the extended directory area 28, already exists, and if not, the directory area expanding means 2 By the third
As shown in the figure, first, the number of expansion requests previously defined in the file description information 21 on the disk is compared with the number of expansions that have been performed so far, and if expansion is still possible, expansion processing is performed. If there is, the subfile description information 23 is registered in the directory overflow area 26.

If it can be extended, the extension process creates a secondary directory area from the directory extension size of the file description information 21 existing on the disk defined in advance,
The number of directory blocks 24 constituting the secondary directory area and the number of expansions are obtained and described in the file description information on the disk. Then, the sub-file name and the extended directory area are again
The directory block 23 to be registered is determined by the hash method using the number of the directory blocks 24 constituting the block 28. Even when the extended directory area 28 exists, the process returns to the directory block checking means 1 described above and repeats the above processing to determine a directory block that can be registered (steps 31 to 37).

When a registerable directory block is found as described above, the subfile description information 23 is registered by the subfile description information registration means 3 to create a subfile.

In referring to the subfile, first, the subfile name and the number of directory blocks in the directory area 22 that existed when the file was created are referred to from the file description information 21 on the disk, and the number of directory blocks is referred to by the hash method. The directory block search unit 4 searches for a directory block 24 in which information is considered to exist.

Next, the sub-file description information search means 5 obtains the sub-file description information obtained by the directory block search means 4.
The directory block 24 in which 23 is supposed to exist is searched to find a desired subfile. If the target sub-file description information 23 does not exist in the directory block 24, the extended directory area search means 6 refers to the file description information 21 on the disc to determine whether or not the extended directory area 28 exists. If not, the process ends.

If it exists, the directory block searching means 4 refers to the number of directory blocks 24 constituting the extended directory area 28 from the file description information 21 on the disk again, The directory block 24 where the sub-file description information 23 is considered to exist by the hash method is found by the name.

Then, the sub-file description information search means 5 searches the directory block 24 obtained by the directory block search means 4 to find a target sub-file. If the target subfile is not found, the directory block search means 4 and the subfile description information search means 5 are executed again until the next extended directory area 28 does not exist. If not, the processing is terminated. .

As described above, registering the sub-file description information 23 in the directory block 24 is because, when referring to the sub-file, random access can be performed using a hash method for each directory area unit of the directory area 22 and the extended directory area 28, so that the access efficiency is improved. Is improved.

〔The invention's effect〕

As described above, in the present invention, the directory extension method of the library type file is set as described above,
The directory area can be expanded without deteriorating the performance of subfile search.

[Brief description of the drawings]

FIGS. 1 and 2 are block diagrams showing the configuration of an embodiment of the present invention, and FIG. 3 is a flow chart showing the processing of the directory extension means of FIG. 1 ... directory block checking means, 2 ... directory expansion means, 3 ... sub-file description information registration means, 4 ... directory block search means, 5 ... sub-file description information search means, 6 ... expansion directory search means. , 7: Library type file, 21: File description information, 22: Directory area, 23: Subfile description information, 24: Directory block, 25: BAM
Area 26 Overflow directory area 27 Data area 28 Extended directory area

Claims (3)

(57) [Claims] 1. A directory area for storing a plurality of directory blocks including sub-file description information of a sub-file, which is a data group having the same attribute, and includes the sub-file description information of the sub-file like the directory area. Library including an extended directory area capable of storing a plurality of directory blocks, an overflow directory area capable of storing at least one of the sub-file description information, and a data area storing a data group of a plurality of sub-files In the type file, when the subfile is created, the subfile description information of the subfile is stored using a hash method based on the subfile name of the subfile and the number of directory blocks in the directory area. The directory A directory block in the area is determined, and it is determined whether the sub file description information of the sub file can be stored in the directory block. If it is determined that the sub file description information cannot be stored, the extended directory area is stored in the library file. Is determined, and if determined to be present, the sub-file description information of the sub-file using a hash method based on the sub-file name of the sub-file and the number of directory blocks in the extended directory area. Directory block checking means for determining a directory block in the extension directory area for storing the sub file description information of the sub file in the directory block, and the directory block checking means Is the subfile If it is determined that the sub-file description information can be stored in the directory block in the directory area, the sub-file description information of the sub-file is stored in the directory block in the directory area, and the If it is determined that the subfile description information can be stored in a directory block in the extended directory area, the subfile description information of the subfile is stored in a directory block in the extended directory area, and the subfile If it is determined that the sub-file description information cannot be stored in the directory block in the extended directory area, the sub-file description information registration means for storing the sub-file description information of the sub-file in the overflow area Specially equipped Directory extension system of library-type file to be. 2. A directory area extension means for judging whether the extension directory area can be created in the library file and, when judging that the extension directory area can be created, creating the extension directory area in the library file. If the directory block check means determines that the extension directory area does not exist in the library file, the directory area extension means creates the extension directory area in the library file by the directory area extension means, and Determining a directory block in the extended directory area for storing sub-file description information of the sub-file using a hash method based on the sub-file name and the number of directory blocks in the created extended directory area; Savoff File description information registering means, when the directory block checking means determines to store the sub-file information of the sub-file in a directory block in the extension directory created by the directory area expanding means, 2. The directory extension method for a library type file according to claim 1, wherein the sub-file description information is stored in a directory block in the extension directory area. 3. When referring to the sub-file, a directory block in the directory area is specified by using a hash method based on a sub-file name of the sub-file and the number of directory blocks in the directory area, and It is determined whether the sub-file description information of the sub-file is stored in the directory block. If it is determined that the sub-file description information is not stored in the directory block, the sub-file name of the sub-file and the number of directory blocks in the extended directory area are determined. Directory block searching means for specifying a directory block in the extended directory area using a hash method based on the directory block to determine whether or not subdirectory description information of the subfile is stored in the directory block; By means of If it is determined that the subfile description information of the file is stored in the directory block in the directory area, the subfile description information of the subfile is read from the directory block, and the subfile description information of the subfile is read. A sub-file description information search unit that reads sub-file description information of the sub-file from the directory block when it is determined that the sub-file is stored in a directory block in the extended directory area. Item 2. A directory extension method for a library type file according to item 2.