JP2630103B2 - File space reservation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file space securing system, and more particularly to a file space securing system characterized by securing and relocating an extended space when a request for expanding a file space is made.

[0002]

2. Description of the Related Art The conventional file space securing method is based on the principle that, when a file space expansion request is made, a continuous space area larger than the requested size is searched for and used as an expansion space. When it cannot be secured, the necessary space is secured by dividing.

[0003]

As described above, the conventional file space securing method is based on the principle that the requested size is secured collectively irrespective of the area where the file requested to be extended is currently secured. Therefore, even if there is an unused space in the area adjacent to the current file, if the requested size is not satisfied, the area is not set as the expansion space. Therefore, there is a problem that if expansion is repeated, the file space is likely to be fragmented, and data input / output delay is likely to occur.

To solve this, the file space is relocated. This file relocation process is started by
It is left to the discretion of the user or the operation manager, and there is a possibility that the state in which the file device is fragmented may continue for a long time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a file space securing method capable of avoiding fragmentation of a file when a file space is expanded and reducing the delay of data input / output without performing relocation processing.

[0006]

According to the present invention, there is provided a file space securing system, comprising: a file device in which a file descriptor holding position and size information of a file space allocated to each file is stored together with the file; A descriptor table that stores the file space position and size information of the file that has been damaged, the expansion request size, a space management table that stores information on whether the space in the file device is in use or unused, and a file space. A relocation start table for storing information of a file for which data is to be relocated, and a file descriptor of a file requested to be expanded are read from the file device and necessary information is set in the descriptor table to secure a file space. The file extension means to be instructed and the file extension means Referring to the descriptor table and the space management table, when a file space is secured from a place adjacent to an area where a file is currently secured, and a file space is secured adjacently, a file is stored in the relocation start table. A space securing unit for registering information, and referring to the relocation start table at regular time intervals, the registered file is not in use, and the array of space descriptors indicating the position and size of the file space is not in ascending address order. A file relocation means for relocating data in the file space, and a work file device for temporarily saving a file when relocating data in the file space.

[0007]

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

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention.

The file space securing method of this embodiment is as follows.
As shown in FIG. 1, a file device 1 in which file descriptors 11 and 12 which are file management information are stored, a descriptor table 4 holding information of a file for which an extension request has been made, A file extension unit 2 that reads the file descriptor 11 of the file having the error from the file device 1 and sets necessary information in the descriptor table 4 to activate the space securing unit 3; A space securing means 3 for preferentially securing a file space from an area adjacent to the secured area, a space management table 5 for managing information on used / unused space of the file device 1,
A relocation activation table 6 in which file information for which data relocation in the file space is determined to be valid by the space securing means 3 is stored, and data of a file registered with reference to the relocation activation table 6 at regular time intervals. The system comprises a file relocation unit 7 for performing a relocation process, and a work file device 8 for temporarily saving data of a file related to the file relocation process.

FIG. 2 is an explanatory diagram showing the structure of the file descriptor 11 stored in the file device 1 and the relationship with the file space. The file descriptor 11 includes a file name 21, a file size 22, a file use flag 23 indicating a file use state, file attribute information 24 indicating file organization and the like, and a space indicating the position and size of each file space constituting the file. Descriptor (fs
1, fs2, fs3,...).

For example, in FIG. 2, the file name is "F
1 "file is a space descriptor fs1, fs2, f
Spaces FS1, on the file device 1 having a start address and a space size respectively indicated by s3.
FS2, FS3....

FIGS. 3A to 3C are format diagrams showing the structures of the descriptor table 4, the space management table 5, and the relocation activation table 6, respectively.

In the descriptor table 4, as shown in FIG. 3A, a file entry 30 is reserved for each file for which a file space expansion request has been made, and each file entry 30 has a file description on the file device 1. File descriptor pointer 31 indicating the position of child 11, file name 3
2, an extended request size 33 and a space descriptor sequence 34.

In the space management table 5, as shown in FIG. 3B, a device entry 35 is secured for each file device 1, and an unused space descriptor string 3 indicating an unused area is provided.
6 and a used space descriptor string 37 indicating a used area
A plurality of space descriptors indicating the position and size of each area are sorted in ascending order by the start address on the file device 1 and stored.

In the relocation start table 6, as shown in FIG. 3C, a start entry 38 is provided for a file for which file space relocation is determined to be valid, and a file name 39 and a file descriptor 11 are provided. And a file descriptor pointer 40 indicating the storage location of the file.

Next, the operation of this embodiment will be described with reference to FIGS.
This will be described with reference to the flowchart of FIG.

First, the file extension processing by the file extension means 2 will be described with reference to FIG.

The file expansion means 2 reads the file descriptor 11 relating to the file requested to be expanded from the file device 1 (step 41), secures the file entry 30 in the descriptor table 4, and reads the file descriptor 11 A file descriptor pointer 31, a file name 32, an extension request size 33, and a space descriptor sequence 34 are set from the information of the extension request and the input information of the extension request (step 42).

Next, the space securing means 3 is activated to make a space securing request for the expansion request size (step 4).
3). When the space securing by the space securing means 3 fails, the file extension requester is notified of the fact and the process is terminated (step 46). If the space is successfully reserved, the space descriptor column 34 in the file entry 30
Is added by the space securing means 3 to the new space descriptor string 3
4a replaces the space descriptor string 25 of the previously read file descriptor 11 (step 44), and writes the file descriptor 11 back to the file device 1 (step 4).
5). Thus, the process of expanding the file space ends.

Next, a description will be given, with reference to FIG. 5, of a process for securing a space for an extended request size by the space securing means 3.

The space securing means 3 includes a descriptor table 4
The file entry 30 for which the space reservation request has been made is acquired, and the space descriptor of the last entry of the space descriptor column 34 is set as the target descriptor (step 5)
1). Then, an area that can be combined with the area where the file space of the target descriptor is secured, that is, the space descriptor of the adjacent area is stored in the unused space descriptor string 3
6 is retrieved (step 52).

If there is an unused space descriptor which can be combined, the space descriptor is deleted from the unused space descriptor column 36 and inserted into the used space descriptor column 37 (step 53). The used space descriptor is added to the space descriptor column 34 in the file entry 30 of the descriptor table 4 (step 54). Step 5
Processes 3 and 54 are a series of common processes of adding an unused space descriptor to the space descriptor sequence of a file for which an expansion request has been made.

When a space descriptor that can be combined is secured, the relocation of the file space is effective. Therefore, the activation entry 38 is secured in the relocation activation table 6 to perform the relocation of the file space. , File name 39 and file descriptor pointer 40 in descriptor table 4
And register it (step 55).

Further, it is determined whether or not the secured file space satisfies the expansion request size by using "expansion request size 33-size of searched unused space descriptor" (step 56). If the file space can be secured, the space securing process ends. At this time, if there is an extra space, the space descriptor is divided, and the space descriptor corresponding to the divided extra space is returned to the unused space descriptor column 36. On the other hand, if the expansion request size cannot be secured and additional space is required, the process returns to step 52 to repeatedly search for an unused space descriptor that can be connected to the opposite side of the target descriptor.

If there is no unused space descriptor that can be combined with the target descriptor in the search in step 52, the target descriptor is set to the space descriptor set as the current target descriptor in the space descriptor column 34. Set to the previous step 5
The processing from step 2 is repeated (step 57).

If the target descriptor no longer exists in step 57, that is, if there is no unused space descriptor that can be combined with the space descriptor in the space descriptor string 34, the process proceeds to the next process. First, the space descriptor string 34 is sorted on the internal table in ascending order by the start address on the file device 1 (step 58), and the space descriptor string 34 is located in the range from the position indicated by the first space descriptor to the position indicated by the last space descriptor. Then, an unused space descriptor having a descriptor size equal to the extended request size 33 is searched from the unused space descriptor column 36 (step 59).

If there is a corresponding unused space descriptor, the process A is performed using the unused space descriptor as a space descriptor for expansion, and the space securing process is completed (step 60).

If there is no one having a size equal to the requested size, the unused space descriptors are sequentially searched from the one having the largest descriptor size within the same range (step 6).
1). If there is an unused space descriptor, a process A is performed in which the unused space descriptor is used as an extended space descriptor (step 62). Is determined (step 63), and if the file space for the expansion request size can be secured, the space securing process ends. If the extended request size cannot be secured, the processing from step 61 is repeated while an unused space descriptor exists within the above range.

If the expansion request size is still not satisfied, the search range of the unused space descriptor is changed to the device entry 3.
5 and search for unused space descriptors in order from the area closest to the first space descriptor and the last space descriptor to secure an extended request size (step 6).
4) The process A is performed using the reserved unused space descriptor as the space descriptor for the extension, and the process ends (step 65). On the other hand, if an unused space descriptor for the extension request size cannot be secured, a space securing failure is notified and the processing ends.

As described above, the process for securing the space for the requested expansion size by the space securing means 3 is performed preferentially from the area adjacent to the area where the file is currently secured, so that the file space is not subdivided due to the expansion. Can be

Next, a description will be given, with reference to FIG. 6, of a file relocation process performed by the file relocation means 7 after use of a file is completed.

The file relocation means 7 refers to the relocation activation table 6 at regular time intervals and monitors whether or not the activation entry 38 exists (steps 71 and 72).
When the start entry 38 exists, the file descriptor 11 is read from the file descriptor pointer 40 (step 73), and it is confirmed whether or not the file is currently used by referring to the file use flag 23 (step 74). . As a result, if the file is in use, the file relocation process is not performed, and the process for the next start entry is performed (step 82).

If the file is not in use, the file relocation process is started, the space descriptor string 25 is sorted by the start address on the file device 1, and a new space descriptor string 25a is generated (step 75). Then, the new space descriptor string 25a is compared with the previous space descriptor string 25, and if the space descriptors of both are the same including the arrangement, there is no need for rearrangement. A different first space descriptor is selected, and the following relocation processing is performed on the subsequent space descriptor strings (step 76).

First, the size of a file space represented by a space descriptor sequence after a different space descriptor is obtained, and a work file of that size is secured in the work file device 8 (step 77). Next, data is read from the area indicated by the different space descriptor using the old space descriptor sequence 25, copied to a work file, and transferred (step 78). When the transfer of all data is completed, the data is transferred again from the work file to the file of the file device 1 using the new space descriptor string 25a (step 79).

When the retransfer of the file is completed, the space descriptor column 25 of the file descriptor 11 is updated with the new space descriptor column 25a and written back (step 80), and the work file is deleted from the work file device 8 The relocation processing for this file ends (step 81).
After that, the relocation activation table 6 is positioned as the next activation entry (step 82), the same processing is performed from step 71, the execution is stopped as soon as the processing for all the activation entries is completed, and after a predetermined time elapses, step 71 is performed again. (Step 83).

As described above, the data of the expanded file is rearranged so as to be continuously stored in the area secured so as to be combined with the existing file space when the file is expanded. Note that this file relocation processing
Instead of reallocating the file space, within the allocated file space, the space descriptors are rearranged and joined on the table to ensure data continuity, and only for the necessary files. , Can be processed at high speed.

[0037]

As described above, according to the file space securing method of the present invention, when a file is extended, an area adjacent to the area where the file currently exists is preferentially secured as an extended space. The data in the enlarged area is automatically rearranged after the use of the file is completed, so that segmentation due to file expansion is unlikely to occur, and the continuity of data in the file is easily maintained. Therefore, there is almost no need to artificially relocate the file space, and there is an effect that there is almost no delay in data input / output.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a configuration of a file descriptor and a file space on a file device according to the embodiment.

FIG. 3 is a format diagram showing a configuration of a descriptor table, a space management table, and a relocation start table according to the embodiment.

FIG. 4 is a flowchart illustrating a processing procedure of a file extension unit according to the present embodiment.

FIG. 5 is a flowchart illustrating a processing procedure of a space securing unit according to the embodiment.

FIG. 6 is a flowchart illustrating a processing procedure of a file relocation unit according to the embodiment;

[Description of Signs] 1 File device 2 File expansion means 3 Space securing means 4 Descriptor table 5 Space management table 6 Relocation start table 7 File relocation means 8 Work file device 11 File descriptor 12 File

Claims (1)

(57) [Claims] 1. A file device in which a file descriptor holding the position and size information of a file space allocated to each file is stored together with the file, the position and size information of the file space of the file requested to be expanded, and A descriptor table for storing the extended request size, a space management table for storing information on whether the space in the file device is in use or unused, and a space table for storing information on a file to be relocated in the file space. An arrangement start-up table, file extension means for reading a file descriptor of a file requested to be extended from the file device, setting necessary information in the descriptor table, and instructing to secure a file space; And refer to the descriptor table and the space management table Space securing means for securing the file space preferentially from the area adjacent to the area where the file is currently secured and registering the file information in the relocation start table when securing the adjacent file space; A file for relocating data in the file space when the registered file is not in use and the array of space descriptors indicating the position and size of the file space is not in ascending address order by referring to the allocation start table at regular intervals. A file space securing method, comprising a relocation means and a work file device for temporarily saving a file when relocating data in the file space.