JPH0969058A - Computer system and file management method used in the system - Google Patents

Abstract

(57) Abstract: To reduce the power consumption of a computer system such as a portable electronic information device by reducing the time taken to decompress compressed data each time the data is used. A data management unit 300 checks whether a decompressed file corresponding to a read-requested file name exists in a data storage unit 400. When the decompressed file exists, decompression processing of the compressed file is not performed,
The decompressed file is read from the data storage unit 400.
On the other hand, when the decompressed file does not exist, the data decompression unit 200 decompresses the compressed file. Then, the decompressed file is stored in the data storage unit 400 in association with the compressed file. Therefore, for a compressed file that has once been requested to be read, the decompressed file corresponding to the compressed file will exist in the file storage device from the next read request, and the decompressed file can be immediately read without performing decompression processing. It will be possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer system for managing file input / output to / from a file storage device capable of storing a plurality of files and a file management method used in the system.

[0002]

2. Description of the Related Art Generally, data permanently owned by a computer system is stored in a nonvolatile storage medium such as a disk in logical units called files. Software that allocates a logical data unit called a file to each storage portion of a physical nonvolatile storage medium is called a file system.

Data managed as files include text, still images, moving images, voices, and the like. Also, some data may be a combination of multiple media such as images and sounds. Of the media, image and audio data in particular require a large storage capacity, and a huge amount of data will occupy the storage capacity. Therefore, it is necessary to compress the data to save the storage capacity.
Research and development have been conducted on compression methods such as PEG and audio ADPCM.

In recent years, it has become possible to carry electronic devices such as sub-notebook personal computers and electronic notebooks and use electronic information at any time and place. For example, in a sub-notebook computer, the minutes of meetings and personal schedules created in the office are stored as data files in a built-in storage medium, and electronic information can be viewed and edited when you are in the train or at home. Can be utilized. In this way, since portable information devices are supposed to be carried around,
Due to size and weight restrictions, it is not possible to mount many storage media like information devices used in a stationary manner in an office or the like, and there is a problem that the storage capacity is limited. For this reason, especially in portable information devices, it is necessary to compress the data and store it as a compressed file in order to save the storage capacity.

Further, in the portable information equipment, it is necessary to suppress the consumption of the battery in order to prolong the operating time. In electronic information devices, compressed files have been stored in the past, and data has been used through programs such as applications that can handle compressed files. When receiving a data use request from the user, the program temporarily expands the compressed file and provides it. In this case, the data is not only temporarily expanded in the storage space but saved in the storage medium, and it takes time to expand each time the compressed file is used, which consumes power. was there.

[0006]

As described above, in the conventional computer system, the compressed file is used to save the storage capacity of the storage medium, but it is expanded every time the compressed file is used. Processing was required. Therefore, the portable electronic information device has a drawback that it consumes a lot of power.

The present invention has been made in view of the above circumstances, and a computer capable of reducing the time taken to decompress compressed data each time a compressed file is used and reducing power consumption. The purpose is to provide a system and a file management method.

[0008]

According to the present invention, in a computer system for managing file input / output to / from a file storage device capable of storing a plurality of files, a compressed file stored in the file storage device is expanded. Decompressing means for decompressing the decompressed file decompressed by the decompressing means, and storing the decompressed file decompressed by the decompressing means in the file storage device in association with the compressed file. It is checked whether the file exists in the storage device, and if it exists, the decompressed file is read from the file storage device and given to the request source of the file read request, and if it does not exist, the compressed file corresponding to the request is decompressed. File management that causes the means to decompress and provides the decompressed decompressed file to the request source Characterized by comprising a stage.

In this computer system, when a file read request is issued from a user program or the like,
It is checked whether the decompressed file corresponding to the request exists in the file storage device. When the decompressed file exists, the decompressed file is not decompressed, and the decompressed file is read from the file storage device and sent to the data request source. On the other hand, if the decompressed file does not exist,
The decompression means decompresses the compressed file. And
The decompressed file is stored in the file storage device in association with the compressed file. Therefore, for a compressed file that has been read once, the decompressed file corresponding to the compressed file will exist in the file storage device from the next read request, and the decompressed file can be immediately read without performing decompression processing. It will be possible.

In a portable electronic information device or the like, since the capacity of a storage medium usable as a file storage device is limited, all data used in the electronic information device is stored in the file storage device as a compressed file. There are many cases. However, according to this system configuration,
Since the decompression process is necessary only when the compressed file is first used, the average time required for the decompression process of the compressed file can be reduced. Therefore, it is possible to provide a computer system suitable for realizing a portable electronic information device in which the storage capacity of the storage medium is small and power consumption is required to be reduced.

Further, in the computer system in which the compressed file and the decompressed file are stored in association with each other in this way, only the compressed file is updated by the user program or the like, and the old decompressed file corresponding to the pre-updated compressed file is stored in the file. It is conceivable that a situation may occur in which the device is left behind. Therefore, when the decompressed file is read and used, it is checked whether the compressed file is a newer file than the decompressed file by comparing the creation date and time of the decompressed file and the corresponding compressed file. It is preferable that the decompressed file is read and given to the request source only when the file is not newly created than the decompressed file, that is, when the compressed file has not been updated.

Further, in the computer system in which the compressed file and the decompressed file are stored in association with each other in this manner, a large amount of storage capacity is occupied by the storage of the decompressed file. It is preferable to provide a file erasing means for automatically erasing the decompressed file from the file storage device. Even if the decompressed file is erased, the decompressed file can be restored from the corresponding compressed file in the file storage device, so that it has little influence on the user. Therefore, it is possible to efficiently secure the free space in the file storage device.

The selection of the decompressed file to be deleted is
It is desirable to select the file to be deleted in accordance with the priority of the decompressed file in consideration of the magnitude of the effect of the file deletion on the user. Here, the priority of a file is an index indicating how much the deletion of the file affects the user. As a method of assigning this priority, it is preferable to increase the priority of a decompressed file that has been referred to recently, or to increase the priority of a decompressed file that has been referred many times, according to the reference history of the decompressed file.

Further, for each compressed file stored in the file storage device, information indicating whether or not to store the decompressed file is registered in advance, and only for the compressed file or the like that needs to be referred many times, The decompression file may be saved.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the basic configuration of a computer system according to the first embodiment of the present invention. This computer system includes a CPU, a memory, an auxiliary storage device,
And a general computer having hardware resources such as various I / O devices. The file management function of this computer system is used for electronic information in which the capacity of the auxiliary storage device for storing files is relatively small. Since it is suitable for a device, a case where the computer system is a portable electronic information device such as a PDA or a sub-notebook computer will be described below as an example.

As shown in FIG. 1, in the electronic information device of the first embodiment, the data utilization unit 100 includes a data utilization request acceptance unit 10 that receives a file operation request from the user program 1 and the like, and a data utilization request. Request acceptance section 1
The request analysis unit 20 analyzes the contents of the file operation request received by the 0, and the data output unit 30 receives and outputs the data file sent from the data management unit 300.

The operation related to the file may be requested not only by the user program 1 but also by an OS level command issued in response to a key input operation by the user. In either case, the operation is viewed from the data use unit 100. And will be required by other programs. Therefore, here, the request from the user is also treated as the request from the program 1.

The data decompression unit 200 includes a data management unit 30.
Upon receiving a data decompression request from 0, the compressed data file in the data storage unit 400 is decompressed. The data management unit 300
It is checked whether or not the decompressed data file of the data file that has received the usage request exists in the data storage unit 400, and if the decompressed data file exists, it is sent to the data use unit 100, and if the decompressed data file does not exist, the data decompression is performed. A data decompression request is issued to the unit 200, and the data file decompressed by the data decompression unit 200 is sent to the data utilization unit 100.

Here, the data utilization unit 100, the data decompression unit 200, and the data management unit 300 are realized by being incorporated into the operating system as the file management unit thereof, or operated on the operating system. It is realized as a program.

The data storage unit 400 is a non-volatile auxiliary storage device for storing the data used in this electronic information device as a file, and is composed of a hard disk, a flash memory card, or the like. In the data storage unit 400, a compressed data file and a decompressed file obtained by decompressing the compressed data file are stored in association with each other.

Next, a procedure for using the data file in the electronic information device of FIG. 1 will be described. FIG. 2 is a display example of data items. The user can use the contents by selecting the data item to be used from the items displayed on the screen of the electronic information device. The data of each item displayed on the screen is stored as a compressed file in the data storage unit 400. These compressed files are
It is downloaded from an information source such as a host computer to an electronic information device via a telephone line, a digital network, or a medium such as radio waves or light.

FIG. 3 is a data display example, which corresponds to the case where the data item “today's weather forecast” is selected. FIG. 4 is a flowchart showing a procedure of file management processing in the electronic information device of FIG.

When a data usage request such as a file read from the user program 1 is issued, the request is accepted by the data usage request acceptance unit 10 (step 4-1). The data use request acceptance unit 10 sends the received request to the request analysis unit 20, and the content of the request is analyzed there (step 4-2). When the request content is a read request for the compressed data file, the request analysis unit 20 requests the data management unit 300 to read the corresponding data file. If the request content is not a data file read request, the request analysis unit 20 performs file operation processing such as writing according to the request.

The data management unit 3 which has received the data read request
00 checks whether or not there is an expanded data file corresponding to the requested compressed data file in the data storage unit 400 (step 4-3). The presence of the decompressed data file can be confirmed by the data file name. For example, the compressed data file name has an extension indicating the compression format added after the file name of the decompressed data file. FIG. 5 shows an example of the data file name.
When a read request for the text data file with the file name “text” is made, the data management unit 300 checks whether or not the decompressed data file with the file name “text” exists in the data storage unit 400.

When the decompressed data file "text" exists, the data management unit 300 reads the decompressed data file "text" from the data storage unit 400 and sends it to the data use unit 100 (step 4-7). As a result, the decompressed data file "text" is given to the user program 1 (step 4-8).

When the decompressed data file "text" does not exist, the data management unit 300 issues a data decompression request to the data decompression unit 200. Upon receiving the data decompression request from the data management unit 300, the data decompression unit 200 searches for the compressed data file "text.gz" having the file name specified by the data read request and decompresses it (step 4-4). In this case, the data decompression unit 200 determines the data compression format from the extension of the data file name and decompresses the compressed data according to the compression format. The data decompression unit 200 sends the decompression data file to the data management unit 300.

The data management unit 300 is a data storage unit 400.
If there is enough free space to store the decompressed data file, the decompressed data file is stored as the "text" (steps 4-5 and 4-6). And the data management unit 3
00 sends the decompressed data file "text" to the data use unit 100 (step 4-7).

The data utilization unit 100 is a data management unit 300.
The decompressed data file "text" received from the above is output to the data output unit 30 and given to the user program 1 (step 4-8).

On the other hand, when there is no free space for storing the decompressed data file in the data storage section 400, the decompressed data file is provided only to the user program 1 and is not saved.

As described above, in the electronic information device of the first embodiment, when the decompressed data file does not exist, the data decompressing unit 200 decompresses the compressed data file, and the data storage unit 400 is associated with the compressed file. Stored in. Therefore, for a compressed data file that has been requested to be read once, a decompressed data file corresponding to the compressed data file will exist in the data storage unit 400 from the next read request, and the decompressing process will be immediately performed. Can be read out.

In the above example, the data decompression unit 20
0 stores the decompressed data file if the data storage unit 400 has a storage capacity enough to store the decompressed data file, but this is not the case. For example, whether or not to store the decompressed data file may be determined depending on the type of the data file.

For example, for a data file such as an article in a newspaper, which has a low probability of being used once if used once,
It is not always necessary to store the decompressed data file. Therefore, the user decides in advance for each compressed file whether to store the expanded data file according to the type of data,
The information may be registered in a table or the like in the data management unit 300, and at the time of reading the compressed file, the registration information may be used to decide whether or not to store the decompressed data file. The procedure of the file management process in this case is shown in FIG.

In the flowchart of FIG. 6, step 6-1 is added between steps 4-4 and 4-5 of the flowchart of FIG. In step 6-1 the data management unit 300 determines whether or not the data decompressed by the data decompression unit 200 needs to be stored as a decompression data file according to the information registered in the table. When it is necessary to store the data, the data management unit 300 stores the decompressed data file in the data storage unit 400, if there is enough storage capacity (steps 4-5 and 4-6). On the other hand, when there is no need to store the decompressed data file, or when there is not enough free space to store the decompressed data file, the data management unit 300 stores the decompressed data “te” in the data storage unit 400.
xt "is not stored and the decompressed data file is sent to the data use unit 100 (step 4-7).

By selectively storing the decompressed data file in this manner, the storage area of the data storage section 400 can be used efficiently. By the way, in the file management processing described with reference to FIGS. 4 and 6, the only condition for decompressing the compressed data is whether or not the decompressed data exists in the data storage unit 400. Is not used. Therefore, when only the compressed data file is updated by the user or the data administrator, the old decompressed data file remains in the data storage unit 400, and the user cannot refer to the updated data. May occur.

To prevent this, the condition for decompressing the compressed data file is not only whether or not the decompressed data file exists in the data storage section 400, but it may be provided separately. In this case, when the data read request is received, even if the decompressed data file associated with the compressed data file exists in the data storage unit 400, the decompressed data file is compared with the creation date and time of the compressed data file and compressed. If the data file is newer, it is preferable to provide a condition that a new decompressed data file is recreated from the compressed data file. FIG. 7 shows the procedure of the file management process in this case.

In the flowchart of FIG. 7, step 7-1 is added between steps 4-3 and 4-7 of the flowchart of FIG. That is, the data management unit 300 checks whether or not there is a decompressed data file corresponding to the requested compressed data file in the data storage unit 400 (step 4-3), and if there is, decompressed data file and compressed data file. The creation dates and times are compared (step 7-1). Normally, in a file system, file creation date / time information is saved as file management information such as a directory entry in the file creation / saving, so that the information may be referred to in step 7-1.

If the compressed data file is newer, the data management unit 300 issues a data expansion request to the data expansion unit 200. Upon receiving the request, the data decompression unit 200 decompresses the compressed data file (step 4-4). On the other hand, if the compressed data file is not newer than the decompressed data file, the decompressed data file is read and sent to the request source (steps 4-7 and 4-8).

Next, an electronic information device according to the second embodiment of the present invention will be described. In the example of the electronic information device of the first embodiment, if the storage capacity for storing the decompressed data file is insufficient, the decompressed data file will be created no matter how many times the request for using the data that only the compressed data file exists is received. Since it is not saved, decompression processing must be performed each time a read request for the compressed data file is issued. In such a case, when the storage capacity of the data storage unit 400 is insufficient, the decompressed data file may be deleted to make a free storage capacity. However, if the data is appropriately deleted, the user can use it. It is not possible to efficiently leave highly decompressed data.

To prevent this, when the decompressed data file is stored in the data storage unit 400 when the decompressed data file is registered in the data management unit 300 with priority,
If the storage capacity is insufficient, it is sufficient to delete the decompressed data files with lower priority in order to create the storage capacity.

As an example of how to give a priority to the decompressed data file, a method of increasing the priority of a recently used file or a method of increasing the priority of a file that has received a large number of read requests is preferable.

FIG. 8 shows the configuration of an electronic information device having such a function of automatically deleting a decompressed data file. As shown in the figure, in the electronic information device, the data use unit 100 includes a data use request receiving unit 10 that receives a data use request from the user program 1 and a data use request receiving unit 10 that receives the data use request. It comprises a request analysis unit 20 for analyzing the contents and a data output unit 30 for receiving and outputting the data sent from the data management unit 300.

The data decompression unit 200 includes a data management unit 30.
Upon receiving a data decompression request from 0, the compressed data file in the data storage unit 400 is decompressed. The data management unit 300
It is checked whether the decompressed data of the data file for which the usage request is received exists in the data storage unit 400, and if the decompressed data file exists, it is sent to the data use unit 100, and if the decompressed data file does not exist, the data decompression unit A data decompression request is issued to the data decompression unit 200, and the decompression unit 200 sends the decompressed data to the data utilization unit 100. Further, the data management unit 300 has a function of managing final read time information, read count information, and the like as information defining the priority of the decompressed data file. The data erasing unit 500 receives the decompression data erasing request from the data management unit 300 and erases the decompression data in the data storage unit 400.

FIG. 9 is a flowchart showing the procedure of the file management process executed by the electronic information device of FIG.
Here, steps 4-4 and 4 of the flowchart of FIG.
Step 9-1 between -5 and Steps 4-5 and 4-
Sup 9-2 is added between 6.

The data management unit 3 which has received the data read request
00 checks whether or not there is an expanded data file of the requested data in the data storage unit 400 (step 4-3). When the decompressed data file exists, the data management unit 300 reads the decompressed data file from the data storage unit 400 and sends it to the data use unit 100 (step 4-7).

On the other hand, when the decompressed data file does not exist, the data management unit 300 issues a data decompression request to the data decompression unit 200. Upon receiving the data decompression request from the data management unit 300, the data decompression unit 200 searches for a compressed data file and decompresses it (step 4-4). in this case,
The data decompression unit 200 determines the data compression format from the extension of the data file name and decompresses the compressed data according to each compression format. The data decompression unit 200 sends the decompression data file to the data management unit 300.

Upon receiving the decompressed data file, the data management unit 300 creates or updates the priority information (reading time, the number of times of reading, etc.) relating to the decompressed data file (step 9-1).

Next, the data management section 300 stores the decompressed data file in the data storage section 400, if there is enough storage capacity (steps 4-5 and 4-6). If there is not enough storage capacity to store the data, the data management unit 300 selects the decompressed data with the lowest priority in order, issues a decompression request for the decompressed data to the data erasing unit 500, and creates a free space for storage (step 9). -2).

As described above, in the electronic information device of the second embodiment, when the free space of the data storage unit 400 is insufficient, the decompressed data file is automatically deleted from the data storage unit 400. Even if the decompressed data file is erased, the decompressed data file can be restored from the compressed data file remaining in the data storage unit 400, so that the influence on the user is small. Further, as described above, by deleting the decompressed data file having the low priority first, the influence on the user can be further reduced. In addition,
Here, the case of handling a data file has been described, but a compressed program file can be handled similarly.

[0049]

As described above, according to the present invention, when reading a compressed file, the compressed file is decompressed and sent to the user program and the like.
The file is stored in the file storage device in association with the compressed file. Therefore, for a compressed file that is once requested to be read, a decompressed file corresponding to the compressed file will exist in the file storage device from the next read request, and the decompressed file can be immediately read without performing decompression processing. It will be possible. Therefore, the time required for decompressing the compressed data can be reduced, and the power consumption of the computer system can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a functional configuration of an electronic information device according to a first embodiment of the present invention.

FIG. 2 is a view showing a display example of data items in the electronic information device of the first embodiment.

FIG. 3 is a diagram showing a display example of data in the electronic information device of the first embodiment.

FIG. 4 is an exemplary flowchart showing a procedure of file management processing in the electronic information device of the first embodiment.

FIG. 5 is a diagram showing an example of file names of files managed by the electronic information device of the first embodiment.

FIG. 6 is a flowchart showing another procedure of file management processing in the electronic information device of the first embodiment.

FIG. 7 is a flowchart showing still another procedure of file management processing in the electronic information device of the first embodiment.

FIG. 8 is a block diagram showing a functional configuration of an electronic information device according to a second embodiment of the present invention.

FIG. 9 is an exemplary flowchart showing the procedure of a file management process in the electronic information device of the second embodiment.

[Explanation of symbols]

10 ... Data usage request acceptance unit, 20 ... Request analysis unit, 30
Data output unit, 100 data usage unit, 200 data expansion unit, 300 data management unit, 400 data storage unit, 500 data deletion unit.

Claims (4)

[Claims] 1. A computer system for managing file input / output to / from a file storage device capable of storing a plurality of files, and a decompression device for decompressing a compressed file stored in the file storage device, and the decompression device. Means for storing the decompressed file decompressed by the file in the file storage device in association with the compressed file, and whether the decompressed file corresponding to the request exists in the file storage device in response to the file read request. When it exists, the decompressed file is read from the file storage device and given to the request source of the file read request. When it does not exist, the decompressed file corresponding to the request is decompressed by the decompressing means, and the decompressed file is decompressed. And a file management means for giving the expanded file to the request source. And computer system. 2. A computer system for managing file input / output to / from a file storage device capable of storing a plurality of files, and a decompression device for decompressing a compressed file stored in the file storage device, and the decompression device. When the compressed file is decompressed by means of means for storing the decompressed decompressed file in the file storage device in association with the compressed file, a decompressed file corresponding to the request in response to a file read request is generated. Means for determining whether or not the file storage device exists, and when it is determined that the decompressed file exists,
Means for comparing the decompressed file and the corresponding date and time of creation of the compressed file to determine whether or not the compressed file is a newer file than the decompressed file; When the file is not a newly created file, means for reading the decompressed file from the file storage device and giving it to the request source of the file read request, and when the compressed file is a file newly created than the decompressed file, Alternatively, when there is no corresponding decompression file in the file storage device, the decompression means decompresses the requested compression file, and the decompression file is provided to the request source. Computer system to do. 3. A computer system for managing file input / output to / from a file storage device capable of storing a plurality of files, and a decompression device for decompressing a compressed file stored in the file storage device, and the decompression device. Means for associating the decompressed file decompressed by the compressed file with the compressed file and storing the decompressed file in the file storage device in response to a file read request, When it exists, the decompressed file is read from the file storage device and given to the request source of the file read request. When it does not exist, the decompressed file corresponding to the request is decompressed by the decompressing means, and the decompressed file is decompressed. Means for providing the requested file to the request source, and the free space of the file storage device. A file erasing unit that starts operation at the same time and erases a file from the file storage device, the file erasing unit selecting and erasing a decompression file to be erased from the decompression files stored in the file storage device. A computer system comprising: 4. A file management method for managing file input / output to / from a file storage device capable of storing a plurality of files, wherein in response to a file read request, a decompressed file corresponding to the request is the file storage device. If it is determined that the file exists, the decompressed file is read from the file storage device and given to the request source of the file read request, and when it is determined that the file does not exist, A file management method comprising decompressing a compressed file corresponding to a request, saving the decompressed decompressed file in the file storage device, and providing the decompressed file to the request source.