JPH10260875A - File management system and file managing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the storage capacity of a storage device from being occupied by unnecessary files and also to save the labor and time of user's file management. SOLUTION: A file managing part 22 records the final access time of each file which is stored in a storage device 21 on a file management table. A data arranging part 23 successively reads the final access time of each file from the file management table and calculates an elapse time from the final access time to the present time. An object to be eliminated is decided in accordance with the elapse time, and the file is partially or entirely eliminated. Or, similarly partial elimination or the elimination of entire data is performed by preliminarily using the processing of file data and a profile that designates the time.

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 used for a personal computer having a large-capacity storage device such as a magnetic disk drive or a magneto-optical disk drive, and more particularly to deleting unnecessary files from a storage device. The present invention relates to a file management system and a file management method characterized by the method of performing the above.

[0002]

2. Description of the Related Art In recent years, computerization has advanced, and the amount of electronic data created has increased. These data are stored as files in a large-capacity storage device such as a magnetic disk device or a magneto-optical disk device.

[0003] Although the capacity of the storage device is increasing year by year, the user needs to add the storage device in accordance with the increasing data amount. If the storage device is not added, the user must delete the data. However, it is extremely difficult to find only unnecessary ones from a huge number of files.

[0004] This is not just a matter of the number of files. For example, some application software used by users automatically creates or reads files without notifying the user, and the user cannot delete files without permission. is there.

[0005]

As described above, conventionally, it is extremely difficult to find only unnecessary files from a huge number of files, and depending on application software, a user deletes files without permission. I couldn't do that. For this reason, there is a problem that the storage capacity of the storage device is occupied by unnecessary files, and new files cannot be added.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to prevent unnecessary files from occupying the storage capacity of a storage device, and to save file management by a user. It is an object to provide a system and a file management method.

[0007]

[Means for Solving the Problems]

(1) A file management system according to the present invention includes: a file storage unit that stores a plurality of files; a file management unit that manages the last access time of each of the files stored in the file storage unit; Elapsed time calculating means for calculating an elapsed time from the last access time to the current time managed by the managing means,
Based on the elapsed time obtained by the elapsed time calculation means, a file to be deleted is determined among the files, and data of the file is partially deleted, or all data of the file is deleted. And a data deleting means for deleting.

The data deleting means compares the elapsed time with a preset time, and if the elapsed time is within the set time, partially deletes the data of the file. When the set time is exceeded, all data of the file is deleted.

Further, the data deletion means determines the data format of the file and partially deletes the data of the file by a method according to the data format. For example, when the data format of a file is an image format, pixels constituting the image data are thinned out at predetermined intervals. In the case of the moving image format, frames constituting the moving image data are thinned out at predetermined intervals. In the case of the mixed image / text format, the image data portion is thinned out.
In the case of the stereo sound format, the stereo data portion is thinned out to obtain monaural data.

According to such a configuration, a file to be deleted is determined based on the elapsed time from the last access time of the file to the current time, and the data of the file is partially deleted by a method according to the data format of the file. Either the data is deleted (decimated), or all the data is deleted (file is deleted). Thus, it is possible to prevent the unnecessary file from filling the storage capacity.

(2) The file management system according to the present invention further comprises: a file storage unit storing a plurality of files;
File management means for managing a file data process and a profile specifying the time for each file stored in the file storage means; and a file management means for managing the file at a specified time of the profile managed by the file management means. And a data deletion means for judging a file to be deleted and partially deleting data of the file or deleting all data of the file.

[0012] The specified time of the profile includes a first time for partially deleting data of a file and a second time for deleting all data, and the data deleting means sets the time at the first time. The data of the file is partially deleted, and all data of the file is deleted at the second time.

Further, the data deleting means determines the data format of the file, and partially deletes the data of the file by a method according to the data format. For example, when the data format of a file is an image format, pixels constituting the image data are thinned out at predetermined intervals. In the case of the moving image format, frames constituting the moving image data are thinned out at predetermined intervals. In the case of the mixed image / text format, the image data portion is thinned out.
In the case of the stereo sound format, the stereo data portion is thinned out to obtain monaural data.

An access frequency managing means for managing a history of the number of accesses for each file, and the first time and the second time based on the history of the number of accesses managed by the access frequency managing means. The profile is created by further including a profile creation unit that estimates a time and creates a profile describing those times.

According to such a configuration, a file to be deleted is determined at a designated time based on the profile, and the data of the file is partially deleted (thinning out) by a method according to the data format of the file. Or all the data is deleted (file deletion).
Thus, it is possible to prevent the unnecessary file from filling the storage capacity.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, in order to facilitate understanding, a file deleting method according to the present invention will be described with reference to FIG. The conventional problem is caused by storing all files that are no longer used as they are. That is, unnecessary files consume a large amount of valuable storage capacity.

Therefore, unnecessary files are automatically deleted. The feature of the present invention is not to simply delete the file, but to gradually reduce the data amount as shown in the conceptual diagram of FIG. By doing so, you can prevent the data in the file from being suddenly lost,
For example, in the case of a bitmap file, the data size of the file can be reduced and the free space can be secured by thinning out data from a detailed image to a rough image.

The start of thinning is determined according to the elapsed time from the last access time of the file to the current time.
When the thinned data is accessed again, the last access time is updated, and further thinning for the file is not performed until the recalculated elapsed time exceeds a predetermined value. Further, the file itself is deleted after another predetermined period has elapsed.

As another method, there is a method of using a profile in which file data processing and its time are designated. By referring to this profile, when the thinning time comes, the data of the corresponding file is thinned according to the file format, and when the deletion time comes,
Delete the file itself.

The files to be thinned out are various data files excluding application software.
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a hardware configuration of a file management system according to one embodiment of the present invention. The process of the present invention is executed by the CPU 11 reading a code on the ROM 12. A file read / write request from outside is received via the I / O 16. Data written from the outside is stored as a file in a large-capacity storage device 14 such as a magnetic disk device or a magneto-optical disk device. This storage device 14
Contains a file, a file management table described later,
Various data required for the processing of the present invention, such as a free block list, is stored. The memory 13 is used as a work area for the thinning process. The timer 15 measures the current time and generates an interrupt signal at regular intervals and at a specified time.

FIG. 2 is a block diagram showing a functional configuration of the present system. The processing of each function is performed by the CPU 11 executing the code on the ROM 12 shown in FIG. Data handled by this system is stored as a file on the storage device 21. In this storage device 21, in addition to an area 21a for storing various files (including profiles), a file management table, a free block list, a time table, a file organization time interval, a file existence time, a thinning start time, an access history management Various areas 21b to 21h for storing tables are provided.

The file management section 22 receives a file read / write request or a file delete request, and creates a file, transfers data, and deletes the file. Data reduction unit 2
Reference numeral 3 includes a processing start determination unit 24 and a thinning processing unit 25. The processing start determining unit 24 calculates the elapsed time from the last access to the file from the last access time and the current time for each file, and determines whether to thin out the file from this value. When it is determined by the process start determination unit 24 to thin out, the thinning-out processing unit 25 reads out the data of the file from the storage device 21 to perform the thinning-out process, and stores the thinned-out data in the storage device 21 again. When the processing start determination unit 24 determines that the file should be deleted, the thinning processing unit 25 deletes all data of the file.

The R / W processing unit 26 receives a read /
The write request is received and transmitted to the file management unit 22, and the current time is acquired from the timer 27 and set as the last access time in the file management table. Further, the memory 28 is provided with a work area 28a when the thinning processing unit 25 performs the thinning processing.

FIG. 4 shows the structure of the file management table. The file management table is for managing files on the storage device 21 and includes files such as “file name”, “format”, “in use flag”, “last access time”, “size”, and “storage address”. Become.

There are two types of file management tables, (a) a method that does not use a profile and (b) a method that uses a profile, depending on the processing start determination method. The profile (see FIG. 6) is a file in which data processing of the file and its time are designated.
In the file management table of the method (b), an area “profile” for storing a profile name corresponding to each file is added.

The "file name" is an area for storing a name for distinguishing a file when the file is created. The “in use flag” is an area for storing a flag for performing exclusive control of a file. If the busy flag is set, the R / W processing unit 26
Sends a request to access this file to the file management unit 22.
Do not send to. The “last access time” is an area for recording the time at which the R / W request was made. "Size"
This area stores the size of a file in bytes.
The “storage address” is an area in which the addresses of the sectors of the storage device 21 storing the data of the file are sequentially recorded from the top of the file.

For example, in the case of file1, the data format is an image format, and the last access request was made in 19
It is January 29, 1997, the size is 2000 bytes, and the block addresses of the storage device 21 are “100” and “1”.
01 "," 102 ", and" 103 ".

The profile corresponding to file1 is file1. It is stored on the storage device 21 under the profile name prf. FIG. 5 shows the structure of the free block list. The free block list stores addresses of unused blocks on the storage device 21 as a list. In the example of FIG. 5, “113”, “104”, and “105” are stored as addresses of unused blocks.

FIG. 6 shows the structure of a profile. In the profile, a file thinning time and a deletion time are described. In the example of FIG. 6, a profile corresponding to file1 is shown, and 00:00:00 on April 1, 1999.
Minute, 00:00 on June 1, 1999, 00:00 on August 1, 1999, and 00:00 on October 1, 1999.
It is described that a thinning process is performed at 00:00 on December 1, 1999, and a deletion process is performed at 00:00 on January 1, 2000.

FIG. 7 shows the structure of the time table. In the time table, scheduled times of processing for each file obtained from the profile are sequentially stored. In the example of FIG.
It is shown that file1 is thinned out at 00:00 on April 1, 1999.

Next, the processing of the file management unit 22 will be described. (File Write Processing) The file management unit 22
When a file write request is received via the processing unit 26, it is checked whether the received file name exists in the file management table.

If the received file name does not exist in the file management table, the file management unit 22 stores the received file name in a new tuple (table row) of the file management table, and deletes from the free block list the data size. Allocate a block (delete from the free block list). Then, the data received from the R / W processing unit 26 is transferred to the assigned block,
The address of this block is recorded in the “storage address” area of the file management table.

If the received file name exists in the file management table, the file management unit 22 adds the R / W processing unit 2 to the block of the storage device 21 at the storage address.
6 is transferred. If the received data does not fit in the block at the storage address (when the file size increases), allocate the increased data to a block from the free block list, transfer the data to that block, and transfer the data to that block. Add the address to the "storage address" area.

If the addresses of blocks to which the received data has not been written are in the "storage address" area (when the file size is reduced), those block addresses are added to the free block list. The file format is determined by the file management unit 22 when writing to this file.
/ W processing unit 26 to set.

(File Read Processing) File Management Unit 2
Upon receiving a file read request via the R / W processing unit 26, the 2 searches for the received file name from the file management table, reads data from the block at the storage address, and transfers the data to the R / W processing unit 26. .

(File Deletion Processing) File Management Unit 22
Receives a file deletion request via the R / W processing unit 26, searches the received file name from the file management table, deletes the file name, adds the block at the storage address to the free block list,
Clear that tuple.

Next, the processing of the processing start determination section 24 of the data reduction section 23 will be described. Here, the respective processing operations will be described separately for (a) a method not using a profile and (b) a method using a profile.

(A) Method not using a profile FIG. 8 shows a flow of the processing start determining unit 24 in a method not using a profile. The processing start determination unit 24 is started by the timer 27 at a file organization time interval (present on the storage device 21).

After startup, the processing start determining unit 24 first selects a file from the top of the file management table (step A11). The processing start determination unit 24 reads the last access time of the file and also reads the current time from the timer 27 to obtain the elapsed time from the last access time of the file to the current time (step A1).
2).

Here, the processing start determination unit 24 reads out the file existence time (existing on the storage device 21) and the thinning start time (existing on the storage device 21) (step A13). The file existence time is a time limit for keeping the file, and is, for example, one year. The thinning start time is an interval time at which thinning is performed, and is, for example, two months. These times are set in advance, but may be arbitrarily set by the user each time.

When the file existence time and the thinning start time are read, the processing start determination unit 24 first compares the elapsed time with the file existence time (existing on the storage device 21), and calculates the elapsed time from the file existence time. If the file is long (Yes in step A14), it is determined that the file is unnecessary, and the file name is passed to the thinning processing unit 25 to notify that it is deleted (step A15). Upon receiving the notification, the thinning processing unit 25 deletes all data of the file.

On the other hand, if the elapsed time is shorter than the file existence time and longer than the thinning start time (Yes in step A16), the processing start determining unit 24 determines that thinning is to be performed, and the file management table Is set to "1", the file name is passed to the thinning processing unit 25, and the data of the file is thinned (step A17).

When the deletion or thinning process is completed as described above, the thinning processing unit 25 notifies the processing start determination unit 24 of that. Upon receiving this notification, the processing start determination unit 24 moves to the next tuple in the file management table and checks for the existence of the file. If a file exists (Yes in step A18), the file is selected and the same processing as described above is performed. If there is no file (No in step A18), the processing ends.

(B) Method of Using Profile When the file management unit 22 creates a profile, it notifies the processing start determination unit 24 of the creation of the profile. In addition,
A method of creating a profile will be described later with reference to FIGS.

After receiving the profile creation notification, the process start determining unit 24 reads the profile from the storage device 21 and records the start time of the thinning process or the deletion process in the time table. The time table exists on the storage device 21. In addition, the time tables are sorted in order of earliest start time.

FIG. 9 shows the flow of the processing start determination section 24 in this method. The timer 27 notifies the processing start determination unit 24 of the event when the start time comes. Upon receiving the event (step B11), the processing start determination unit 24 acquires the file name of the file to be processed and the processing content (thinning / deletion) with reference to the time table (step B12).

In the case of the thinning processing (No in step B13), the processing is executed by the thinning processing section 25 (step B14). In the case of the deletion process (Yes in step B13)
s), the file name of the profile corresponding to the target file name is acquired from the file management table, and a profile deletion request is transmitted to the file management unit 22 to delete the profile. A deletion request is transmitted to the file management unit 22 to delete the file (step B15). After performing the thinning process or the deletion process at the designated time in this way, the processed content is deleted from the time table (step B16).

Next, the processing of the thinning processing section 25 will be described. FIG. 10 shows a flow of the file thinning process in the thinning processing unit 25. The thinning processing unit 25 starts processing by receiving the thinning target file name transmitted by the processing start determination unit 24.

First, the thinning processing section 25 searches the received file name on the file management table to obtain the data format of the file (step C11). In the example of FIG. 4, the data format of a file whose file name is indicated by file2 is a moving image. The thinning processing unit 25
A thinning method is selected according to the data format of this file (step C12).

After selecting the thinning method, the thinning processing unit 25
Issues a read request for this file name to the file management unit 22, and reads the file data from the storage device 21 to the work area 28a of the memory 28 (step C1).
3). The thinning-out section 25 executes thinning-out processing on the read data by the thinning-out method selected previously (step C14). When the thinning processing is completed, the thinning processing unit 25 issues a write request to the file management unit 22 with the file name, and stores the thinned data in the storage device 21 again (step C15).

Here, a specific example of the thinning process according to the data format of the file is shown in FIGS. When the data format of the file is an image (bitmap image) format, pixels constituting the image data are thinned out at predetermined intervals. In this case, as shown in FIG. 11, pixel data is thinned out at regular intervals in the X-axis and Y-axis directions to reduce the data size. Although there are various methods for thinning pixels, the present invention is not limited to these methods.

When the data format of the file is a moving image format, as shown in FIG. 12, the images (called frames) arranged on the time axis are thinned out at predetermined intervals to reduce the number of frames to reduce the data size. I do. Also in this case, there are various methods for thinning out the frame, but the present invention is not limited to these methods.

When the data format of the file is a mixed image / text format, the data size is reduced by deleting the image data portion as shown in FIG. However, this method is performed only once, and cannot be thinned out in several times as in the case of the image data or the moving image data described above.

When the data format of the file is a stereo audio format, as shown in FIG. 14, the data of the difference between the left and right audio signals, that is, the stereo data portion is deleted to make the data monaural, thereby reducing the data size. . However,
This method is also performed only once, and cannot be thinned out in several times as in the case of the image data or the moving image data described above.

Next, a method of creating a profile will be described. The profile is a file in which data processing of the file and its time are designated (present on the storage device 21). Although this profile can be created by the user, it is assumed here that the profile is created automatically by the system. In this case, the user can edit what the system has created. The creation of the profile is performed by the file management unit 22. The file management unit 22 shown in FIG.
The thinning start time and the deletion time of the file are predicted with reference to the access history management table (present on the storage device 21) as shown in FIG.

More specifically, first, the number of file accesses is counted every predetermined period from the file creation date, and this is recorded in the access history management table.
This access history management table exists on the storage device 21. In the example of FIG. 15, the number of accesses for six months is recorded. From the history of the past six months of the number of accesses, a day when the number of accesses becomes “0” is predicted, and that day is set as the thinning start time.

For example, in file1, "100", "9"
The number of times of access has decreased, such as “0”, “80”, “70”, “60”, “50”. This is graphed as shown in FIG. 16, and the day when the access count becomes “0” can be approximately obtained by the first-order approximation method.

After the thinning start time is obtained in this way, the thinning time may be set at predetermined intervals. As for the deletion time, as shown in FIG. 17, assuming that the period from the file creation time to the thinning start time is T, the time obtained by adding the period of T from the thinning start time is the deletion time. In addition, the period to be added to the thinning start time may be variously changed according to, for example, the length of the T.

When the thinning start time and the deletion time of a file are predicted by such a method, the file management unit 2
2 describes these times in a profile and stores them in the storage device 21.

As described above, in the method that does not use the profile, the file to be deleted is determined based on the elapsed time from the last access time, and the data is thinned out stepwise by a method according to the data format of the file. , To reduce the data size. If a certain period has elapsed, the file itself is deleted. This allows
It is possible to prevent the storage capacity of the storage device 21 from becoming full of unnecessary files, and to thin out the files in stages, so that the contents of the files can be confirmed to some extent on the way.

In the method using a profile,
The file to be deleted is determined at the designated time based on the profile, and the data size is reduced by thinning out the data in a stepwise manner according to the data format of the file. At another designated time, the file itself is deleted. Thus, as described above, it is possible to prevent the storage capacity of the storage device 21 from being filled with unnecessary files. Further, since the file is thinned out step by step, the contents of the file can be confirmed to some extent on the way. it can.

Note that the method described in the above-described embodiment includes, as programs that can be executed by a computer, for example, a magnetic disk (floppy disk, hard disk, etc.), an optical disk (CD-ROM,
It is also possible to write the data on a recording medium such as a DVD or a semiconductor memory and apply it to various devices, or to transmit it via a communication medium and apply it to various devices. A computer that realizes the present apparatus reads the program recorded on the recording medium, and executes the above-described processing by controlling the operation of the program.

[0064]

As described above, according to the present invention, partial deletion (thinning) or all data deletion (file deletion) of a file is performed according to the elapsed time from the last access time of the file to the current time. Thus, it is possible to prevent the unnecessary file from occupying the storage capacity of the storage device, and it is possible to save the user from having to manage the file.

Also, by partially deleting (thinning out) a file or deleting all data (deleting a file) by using a profile in which file data processing and its time are designated in advance, the unnecessary file This can prevent the storage capacity of the storage device from being occupied, and can save the user from having to manage the file.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a hardware configuration of a file management system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a functional configuration of the file management system.

FIG. 3 is a view for explaining the principle of file deletion realized by the present invention.

FIG. 4 is an exemplary view showing the configuration of a file management table in the embodiment.

FIG. 5 is an exemplary view showing a configuration of a free block list in the embodiment.

FIG. 6 is a view showing a configuration of a profile in the embodiment.

FIG. 7 is an exemplary view showing the configuration of a time table in the embodiment.

FIG. 8 is an exemplary flowchart showing the operation of the processing start determination unit in a method not using a profile in the embodiment.

FIG. 9 is an exemplary flowchart illustrating the operation of a processing start determination unit in a method using a profile according to the embodiment;

FIG. 10 is an exemplary flowchart illustrating the operation of a file thinning process in the thinning processing unit according to the embodiment;

FIG. 11 is an exemplary view showing a specific example (in the case of an image format) of thinning processing according to the data format of a file in the embodiment.

FIG. 12 is an exemplary view showing a specific example (in the case of a moving image format) of a thinning process according to a data format of a file in the embodiment.

FIG. 13 is an exemplary view showing a specific example (in the case of a mixed image / text format) of thinning processing according to the data format of a file in the embodiment.

FIG. 14 is an exemplary view showing a specific example (stereo audio format) of the thinning processing according to the file data format in the embodiment.

FIG. 15 is an exemplary view showing the configuration of an access history management table in the embodiment.

FIG. 16 is an exemplary view for explaining a method of estimating a thinning start time described in a profile in the embodiment.

FIG. 17 is an exemplary view for explaining a method of predicting a deletion time described in a profile in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... CPU 12 ... ROM 13 ... Memory 14 ... Storage device 15 ... Timer 16 ... I / O 21 ... Storage device 22 ... File management part 23 ... Data arrangement part 24 ... Processing start determination part 25 ... Thinning-out processing part 26 ... R / W processing unit 27: Timer 28: Memory

Claims (21)

[Claims] 1. A file storage means for storing a plurality of files, a file management means for managing a last access time for each of the files stored in the file storage means, and a file management means for managing the last access time. Elapsed time calculating means for calculating an elapsed time from the last access time to the current time; and determining a file to be deleted among the files based on the elapsed time obtained by the elapsed time calculating means. A file management system comprising: data deletion means for partially deleting data of a file or for deleting all data of the file. 2. The data deletion means compares the elapsed time with a preset time, and if the elapsed time is within the set time, partially deletes data of the file. 2. The file management system according to claim 1, wherein when the time exceeds the set time, all data of the file is deleted. 3. The file management system according to claim 1, wherein said data deletion means determines the data format of the file and partially deletes the data of the file by a method according to the data format. . 4. The file management system according to claim 3, wherein said data deleting means, when the data format of the file is an image format, thins out pixels constituting the image data at predetermined intervals. 5. The file management system according to claim 3, wherein said data deleting means, when the data format of the file is a moving image format, thins out each frame constituting the moving image data at a predetermined interval. 6. The file management system according to claim 3, wherein said data deletion means thins out image data portions when the data format of the file is a mixed image / text format. 7. The file management system according to claim 3, wherein said data deleting means, when the data format of the file is a stereo sound format, decimates the stereo data portion to obtain monaural data. 8. A file storage means for storing a plurality of files, a file management means for managing a file data processing and a profile designating the time of the file data for each of the files stored in the file storage means. At the specified time of the profile managed by the file management means, a file to be deleted is determined among the above files, and data of the file is partially deleted or all data of the file is deleted. A file management system comprising a data deleting unit. 9. The specified time of the profile includes a first time at which data of a file is partially deleted and a second time at which all data is deleted, wherein the data deleting means is configured to execute the first time. 9. The file management system according to claim 8, wherein data of the file is partially deleted, and all data of the file is deleted at the second time. 10. The file management system according to claim 8, wherein said data deletion means judges the data format of the file and partially deletes the data of the file by a method according to the data format. . 11. The file management system according to claim 10, wherein when the data format of the file is an image format, the data deletion unit thins out each pixel constituting the image data at a predetermined interval. 12. The file management system according to claim 10, wherein, when the data format of the file is a moving image format, the data deleting unit thins out each frame constituting the moving image data at a predetermined interval. 13. The file management system according to claim 10, wherein said data deleting means thins out image data portions when the data format of the file is a mixed image / text format. 14. The file management system according to claim 10, wherein when the data format of the file is a stereo audio format, the data deleting means thins out the stereo data portion to obtain monaural data. 15. An access frequency management means for managing a history of the number of accesses for each file, and the first time and the second time based on the history of the number of accesses managed by the access frequency management means. 9. The file management system according to claim 8, further comprising: a profile creation unit that estimates a time and creates a profile describing those times. 16. A file management method for a storage device storing a plurality of files, comprising: a file management table in which the last access time of each file on the storage device is recorded. The last access time of each file is sequentially read, the elapsed time from the last access time to the current time is obtained, and a file to be deleted among the files is determined based on the elapsed time. A file management method characterized by partially deleting data or deleting all data of the file. 17. Comparing the elapsed time with a preset time, if the elapsed time is within the set time, partially delete data of the file; and the elapsed time exceeds the set time. 17. The file management method according to claim 16, wherein in that case, all data of the file is deleted. 18. The file management method according to claim 16, wherein the data format of the file is determined, and the data of the file is partially deleted by a method according to the data format. 19. A file management method for a storage device storing a plurality of files, comprising: a profile specifying file data processing and time for each file on the storage device; A file management method comprising: judging a file to be deleted from each of the above files at a time, and partially deleting data of the file, or deleting all data of the file. 20. The specified time of the profile includes a first time at which data of a file is partially deleted and a second time at which all data is deleted, and the data of the file is stored at the first time. 20. The file management method according to claim 19, wherein the file is partially deleted, and all data of the file is deleted at the second time. 21. The file management method according to claim 19, wherein the data format of the file is determined, and the data of the file is partially deleted by a method according to the data format.