JP2006309400A - Program and device for managing file - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To speed up software processing associated with a cluster chain. <P>SOLUTION: The cluster number of file data is recorded on the cluster chain information field of a file cluster chain item. Accordingly, when the file data is recorded over a plurality of clusters (when the cluster chain is generated) and the processing required for the analysis of the cluster chain is performed, the cluster chain information is acquired by analyzing a field value in the cluster chain information field of the file cluster chain item. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a file management program and a file management apparatus for recording file data based on a FAT file system.

Conventionally, as a file management program, for example, a file system mounted on a Microsoft operating system (Windows (registered trademark) or MS-DOS (registered trademark)), that is, a FAT file system is known (for example, a patent). Reference 1).
In such a file management program, generally, when the size of an area used for recording file data is smaller than the size of one cluster area, the file data is stored in one cluster area. In addition, if the size of the area is larger than the size of one cluster, a new cluster area following the cluster area storing the file data up to the middle is secured, and the file data continues in the secured cluster area. Is stored. When a new cluster area is secured, the link state of the cluster number of the newly secured cluster area is recorded in the FAT as a cluster chain.
JP-A-6-309207

However, in the above conventional file management program, since file data is managed by FAT, there are severe restrictions on hardware performance due to demands for low power consumption and miniaturization, for example. When applied to an embedded device, the analysis processing of the cluster chain of file data may take a lot of time.
An object of the present invention is to solve the above-mentioned unsolved problems of the prior art, and a file management program and a file management apparatus capable of speeding up software (firmware) processing relating to a cluster chain It is an issue to provide.

  In order to solve the above problems, a file management program according to the present invention is a file management program for recording each file data using a cluster chain based on the FAT file system, wherein a cluster storing the file data is recorded. A computer is caused to execute a recording function of recording the indicated cluster chain information in a file cluster chain item for recording the cluster chain information.

Further, an information acquisition function for acquiring the cluster chain information from the file cluster chain item may be executed by a computer.
The file management apparatus of the present invention is a file management apparatus for recording each file data using a cluster chain based on the FAT file system, and includes cluster chain information indicating a cluster storing the directory item. Recording means for recording in a file cluster chain item for recording the cluster chain information is provided.

Furthermore, information acquisition means for acquiring the cluster chain information from the file cluster chain item may be provided.
According to such a configuration, when file data is recorded across a plurality of cluster areas (when there is a cluster chain), when performing processing that requires analysis of the cluster chain, the file cluster chain By analyzing the field value of the item, the cluster chain information can be acquired. Therefore, for example, it is possible to increase the speed (improvement) of software (firmware) processing related to the cluster chain, compared to a method of acquiring cluster chain information by referring to the FAT.

Hereinafter, as an embodiment of a file management program of the present invention, an example applied to a portable terminal including an imaging unit such as a CCD camera capable of generating image data will be described with reference to the drawings.
That is, in the portable terminal 1, when image data is generated by the imaging unit, file data of the image data is stored. At this time, if the file data is stored in a plurality of clusters, the field value indicating the cluster number of the cluster is recorded in the cluster chain information field of the file cluster chain item (the item newly provided in the present invention). . And in this portable terminal 1, when executing processing that requires analysis of the cluster chain, by analyzing the file cluster chain item corresponding to the file to be processed without analyzing the FAT, The said process can be performed efficiently.

<Configuration of mobile terminal>
FIG. 1 is a block diagram illustrating an internal configuration of the mobile terminal according to the present embodiment. As shown in FIG. 1, a portable terminal 1 includes an imaging unit 2, a character input unit 3, a memory card unit 4, a display unit 5, an I / F (Interface) 6, a CPU (Central Processing Unit) 7, a RAM (Random Access memory 8 and ROM (read only memory) 9 are included. The portable terminal 1 is connected to each other by a bus 10 except for the imaging unit 2, the character input unit 3, the memory card unit 4, and the display unit 5.

The imaging unit 2 is arranged in the upper part of the plan view on the back side and includes a CCD camera (not shown). Then, when a predetermined operation is performed, the imaging unit 2 generates image data of the subject with the CCD camera and outputs the image data to the CPU 7 via the I / F 6.
The character input unit 3 includes a keyboard (not shown) capable of inputting an arbitrary character string. Then, the character input unit 3 outputs information on the character string input from the keyboard to the CPU 7 via the I / F 6.

Furthermore, the memory card unit 4 is arranged at the left end in a plan view and is configured to be detachable from a nonvolatile memory card (not shown) that can retain data even when power supply is stopped. Then, when a file storage command (described later) is output from the CPU 7, the memory card unit 4 records a file (described later) generated by the CPU 7 on the memory card.
Further, when a directory item recording command (described later) is output from the CPU 7, the memory card unit 4 records the field value generated by the CPU 7 in the cluster chain information field of the file cluster chain item, as will be described later. The directory item of the file name generated by the CPU 7 is recorded on the memory card. Further, when a directory item read command (described later) is output from the CPU 7 via the I / F 6, the memory card unit 4 reads the directory item of the file name of the file specified by the directory item read command from the memory card. To the CPU 7 via the I / F 6.

Furthermore, the display unit 5 is arranged in a central portion in plan view on the front side, and includes a display device (not shown) that can display an arbitrary image. Then, when the processing result is output from the CPU 7 via the I / F 6, the display unit 5 displays the output processing result on the display device.
In addition, the I / F 6 converts the data exchanged between the units 2 to 5 included in the mobile terminal 1 or between the units 2 to 5 and the CPU 7 into a format that can be read by the receiving side 2 to 5 and 7. To do.

Further, the CPU 7 reads out various programs such as a basic control program (OS: Operating System) and application programs recorded in the ROM 9, executes the read-out various programs, and each unit 2 included in the mobile terminal 1. Control ~ 9.
Further, when the image data is output from the imaging unit 2, the CPU 7 generates file data of the output image data. Further, the CPU 7 receives information on the character string from the character input unit 3 as the file path of the directory in which the generated file data (hereinafter also referred to as “newly generated file data”) is recorded and the file name of the newly generated file data. Is input to the memory card unit 4 via the I / F 6 and at the same time a write process (the file storage command) is recorded to the memory card. (To be described later). Then, when the write process is executed, the CPU 7 determines whether the file data is stored in a plurality of clusters. When stored in multiple clusters, a field value indicating the cluster number of the cluster is recorded in the cluster chain information field of the file cluster chain item, and a directory item recording command for recording the directory item of the file name is issued. After outputting to the memory card unit 4 via the I / F 6, this calculation process is terminated. If the file data is large and the field value is filled in all the cluster chain information fields of the file cluster chain item during the write process, the file cluster chain item subsequent to the file cluster chain item is changed. Reserve and continue writing field values to the reserved file cluster chain item.

Specifically, as shown in FIG. 2, the file cluster chain item includes an index field, a cluster chain information field, a reservation field, an attribute field, and a checksum field.
In the index field, a file cluster chain item number (a number indicating the number of the file cluster chain item) expressed in hexadecimal is set. In the last file cluster chain item, a bit (bit 6) indicating the end of the file cluster chain item is set. Therefore, this bit can be used as a check flag for the internal processing of the firmware, and safety can be improved.

  In the cluster chain information field, a hexadecimal representation of the cluster number of the cluster following the cluster (first cluster) indicated by the field value of the first cluster number field of the subdirectory identification item is set. The area of the cluster chain information field is 4 bytes (32 bits) for FAT32, 2 bytes (16 bits) for FAT16, 3 bytes (24 bits for FAT12, Note: 2 fields information is included (12 bits × 2) The number of cluster chain information fields (number of clusters recordable in the directory item) is 6 for FAT32, 13 for FAT16, and 16 for FAT12 (2 information in 8 fields). To do.

In the reserved field, the same field as the long file name item of the FAT file system (directory item representing the long file name during the VFAT operation) is set.
Information (for example, “0x0F & 0x20”) indicating that this directory item is a cluster chain item is set in the attribute field. The field value “0x0F” is set in the attribute field of the long file name item.

In the checksum field, a numerical value “0x00” that does not match the checksum of the directory item representing the short file name is set. In the checksum field of the long file name item, a numerical value that matches the checksum is normally set.
Therefore, in an operating environment in which VFAT is not installed, this directory item is ignored by the lower 4 bits “0x0F” of the attribute field. In this embodiment, an example in which “0x0F & 0x20” is set in the attribute field is shown, but the present invention is not limited to this, and other information indicating a file cluster chain item may be used.

Similarly, even in an operating environment equipped with VFAT, this directory item is ignored due to the field value of the checksum field (the field value “0x00” that does not match the checksum of the directory item representing the short file name). Is done.
Further, the CPU 7 inputs character string information from the character input unit 3 as the file path of the file to be processed in order to execute processing that requires analysis of the cluster chain on the file data recorded on the memory card. Then, a reading process (described later) is executed. When the read process is executed, the CPU 7 outputs a directory item read command to the memory card unit 4 via the I / F 6 to read the file item and the file cluster chain item corresponding to the file. Further, the CPU 7 reads out the field value of the cluster chain information field from the read file cluster chain item, executes the processing, displays the processing result on the display unit 5, and then ends the reading processing. . When all the field values of the cluster chain information field of the file cluster chain item have been read during the reading process, the file cluster chain item following the file cluster chain item is read and read. Continue reading the field value of the file cluster chain item.

Further, the RAM 8 forms a work area for developing various programs executed by the CPU 7 and a memory area for recording data used when the various programs are executed. When the read request is output from the CPU 7, the RAM 8 outputs data corresponding to the read request from the data recorded in the RAM 8 to the CPU 7.
The ROM 9 records various programs and data executed by the CPU 7. Then, when a read request is output from the CPU 7, the ROM 9 outputs a program corresponding to the read request from the programs and data recorded in the ROM 9 to the CPU 7.

<Operation of mobile terminal>
Next, the writing process executed by the CPU 7 will be described with reference to the flowchart of FIG. This writing process is executed when character string information is input from the character input unit 3 as a combination of the file path of the directory for storing the newly generated file data and the file name of the newly generated file data. When this calculation process is executed, first, in step S101, according to the FAT file system standard, the file item of the newly generated file data and the long file name based on the input character string information Generate item (if long file name is specified). Then, a command for recording the directory item in the cluster corresponding to the directory is output to the memory card unit 4.

Next, in step S102, when the newly generated file data is stored in a plurality of clusters, the cluster number of the cluster is assigned to the cluster chain information field of the file cluster chain item in the same cluster as the long file name item. Set to.
Specifically, in the cluster chain information field, the cluster number recorded in the buffer when the newly generated file is recorded is recorded from the head of the directory item. In addition, “all FF” is recorded in the cluster chain information field after the field in which the cluster number corresponding to the end of the cluster chain is recorded so that the end of the cluster chain becomes clear. At this time, the arrangement format of each field is set according to the format type (FAT12, FAT16, FAT32) of the file system.

  In step S103, field values are set in the reserved field, attribute field, and checksum field of the file cluster chain item stored in the same cluster as the long file name item. Specifically, the same field value as the long file name item is set in the reserved field. In the attribute field, “0x0F & 0x20” is set. Then, “0x00” is set in the checksum field.

  Next, the process proceeds to step S104, and it is determined whether or not the file cluster chain item continues. Specifically, it is determined whether or not the file data has a long cluster chain and the subsequent cluster number cannot be recorded in one file cluster chain item. If one file cluster chain item cannot be recorded, the process proceeds to step S105, and if it can be recorded, the process proceeds to step S106.

  In step S105, the field value of the index field of the file cluster chain item in the same cluster as the long file name item is set, and after creating a new file cluster chain item, the process proceeds to step S102. At this time, if the file cluster chain item in the same cluster is recorded at the head of the sector area, that is, if there is no free area in which a new file cluster chain item can be recorded, it is generated in the next sector. To do. Further, when the next sector is the last sector of the cluster area, a cluster allocation process for securing and generating a new cluster area is performed.

Note that the newly generated file cluster chain item may be recorded, for example, every time it is generated, or may be recorded collectively at the end, and this file system is implemented. Set according to the product specifications.
On the other hand, in step S106, a field value and bit 6 are set in the index field of the file cluster chain item in the same cluster as the long file name item.

Next, the process proceeds to step S107, and a command for recording the field value set in steps S102 to S106 in each field of the file cluster chain item (hereinafter also referred to as “directory item recording command”) is a memory card unit. 4 is output.
In step S108, normal file system processing is executed in accordance with the FAT file system standard, and the calculation processing is terminated.

  Next, the reading process executed by the CPU 7 will be described with reference to the flowchart of FIG. In this reading process, character string information is input from the character input unit 3 as the file path of the file to be processed in order to execute processing that requires analysis of the cluster chain on the file data recorded on the memory card. In step S201, a file item corresponding to the character string to which information is input from the character input unit 3 is read out and output to the CPU 7 (hereinafter referred to as “directory item read”). Command ”) is output to the memory card unit 4 via the I / F 6.

In step S202, the field value “0x2F” of the attribute field of the file cluster chain item in the same cluster as the long file name item or the file cluster chain item specified in step S205 described later is confirmed.
Next, the process proceeds to step S203, and field values are obtained in order from the file cluster chain item in the same cluster as the long file name item or from the first cluster chain information field of the cluster chain item specified in step S205 described later. To do. In this case, valid cluster chain information is before the field in which “all FF” is recorded. Further, since the fields of the file cluster chain item have different formats depending on the format type of the file system, the cluster chain information is acquired from each cluster chain information field with reference to the format type.

  In step S204, it is determined whether the file cluster chain item continues. Specifically, it is determined whether or not the bit (bit 6) indicating the end of the file cluster chain item is recorded in the index field of the file cluster chain item stored in the same cluster as the long file name item. To do. If the bit indicating the end of the file cluster chain item is not recorded (Yes), the process proceeds to step S205. If the bit is recorded (No), the process proceeds to step S206.

  In step S205, a file cluster chain item subsequent to the file cluster chain item in the same cluster as the long file name item is specified, and then the process proceeds to step S202. At this time, if the file cluster chain item in the same cluster is recorded at the head of the sector area, it is specified from the next sector. If the sector is the last sector of the cluster area, the sector is identified from the next cluster.

  On the other hand, in step S206, normal file system processing is executed in accordance with the FAT file system standard, the processing result is output to the display unit via the I / F 6, and the calculation processing is terminated. At this time, if cluster chain information is required, the field value acquired in the above flow is referred to and no FAT scanning process is performed.

<Specific operation of mobile terminal>
Next, the operation of the mobile terminal 1 of the present embodiment will be described in detail based on a specific situation.
<File generation>
First, it is assumed that the image data of the subject is generated by the CCD camera of the imaging unit 2. Then, as shown in FIG. 1, the generated image data is output to the CPU 7 by the imaging unit 2, and file data of the image data is generated by the CPU 7.

  Next, the user uses the keyboard of the character input unit 3 as a combination of the file path of the directory (directory in the memory card) in which the generated file data (newly generated file data) is recorded and the file name of the newly generated file data. Suppose you entered a string from. Then, the CPU 7 outputs a file storage command to the memory card unit 4 via the I / F 6. Then, the memory card unit 4 stores the generated newly generated file data in the directory (the newly generated file is stored in a plurality of clusters and a cluster chain is generated).

  At the same time, a writing process is executed by the CPU 7. As shown in FIG. 3, first, in step S101, the newly generated file data is updated based on the input character string information in accordance with the FAT file system standard. A file item and a long file name item (when a long file name is specified) are generated. Then, the memory card unit 4 records the file item and the long file item in the cluster corresponding to the directory.

  In step S102, the cluster number information field of the file cluster chain item in which the cluster number of the cluster storing the newly generated file data is stored in the same cluster as the long file name item as shown in FIG. Set to In step S103, the same field value as the long file name item is set in the reserved field of the file cluster chain item, “0x0F & 0x20” is set in the attribute field, and “0x00” is set in the checksum field. Then, the determination in step S104 is “No”, and in step S106, the field value and bit 7 are set in the index field of the file cluster chain item.

FIG. 5 shows a state when the newly generated file data is recorded in a cluster chain of cluster numbers 10 → 11 → 12 → 13 → 14 → 15 → 16 → 17 → 18 → 19.
In step S107, a directory item recording command is output to the memory card unit 4 via the I / F 6, and the field values set in steps S102 to S106 by the memory card unit 4 are stored in the file cluster chain items. In step S108, normal file system processing is executed.

<File processing>
In addition, after the above flow is executed and the file data is recorded in the memory card, the file data recorded in the memory card is subject to processing in order to execute processing that requires cluster chain analysis. It is assumed that the user inputs character string information from the character input unit 3 as the file path of the file. Then, the reading process is executed by the CPU 7, and as shown in FIG. 4, first, in step S201, a directory item read command is output to the memory card unit 4 via the I / F 6. Then, the memory card unit 4 reads out the file item corresponding to the file path (file) designated by the user from the memory card and outputs it to the CPU 7.

  In step S202, it is confirmed that the field value of the attribute field of the file cluster chain item stored in the same cluster as the long file name item is “0x2F”. In step S203, the file cluster chain item Effective field values are acquired in order from the first cluster chain information field. That is, the cluster chain information of the file data is acquired without FAT scanning.

  Here, it is assumed that bit 7 is recorded in the index field of the file cluster chain item. Then, the determination in step S204 is “No”. In step S206, normal file system processing is executed according to the FAT file system standard, and the output processing result is output to the display unit via the I / F 6. . Then, the display unit 5 displays the output processing result image data on the display device.

  As described above, in the portable terminal 1 of the present embodiment, the cluster number of the file data is recorded in the cluster chain information field of the file cluster chain item. Therefore, when file data is recorded across multiple clusters (when a cluster chain is generated), when performing processing that requires analysis of the cluster chain, the cluster chain information of the file cluster chain item By analyzing the field value of the field, the cluster chain information can be acquired. Therefore, for example, it is possible to increase the speed of the software (firmware) processing related to the cluster chain as compared with the method of acquiring the cluster chain information by referring to the FAT.

  Further, directory items other than the file cluster chain item are set according to the FAT file system standard. Therefore, the file generated by the portable terminal 1 can be properly recognized even by a personal computer equipped with the FAT file system, and the file can be handled as it is by those personal computers. In other words, the conventional file system can be implemented based on the conventional FAT file system without significantly modifying or changing the conventional file system, and the processes required for introduction can be minimized. Furthermore, it is recognized normally on the conventional FAT file system and VFAT file system, and compatibility can be maintained.

As described above, step S106 in FIG. 3 constitutes the recording function described in the claims, and similarly, step S201 in FIG. 4 constitutes the information acquisition function, and the memory card unit 4, CPU 7, FIG. Step S106 constitutes a recording means, and the memory card unit 4 and CPU 7 in FIG. 1 and step S201 in FIG. 4 constitute an information acquisition means.
Note that the file management program and the file management apparatus of the present invention are not limited to the contents of the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

It is a block diagram which shows the internal structure of the portable terminal in embodiment. It is explanatory drawing for demonstrating a file cluster chain item. It is a flowchart of a writing process. It is a flowchart of a reading process. It is explanatory drawing for demonstrating operation | movement of a portable terminal.

Explanation of symbols

1 is a portable terminal, 2 is an imaging unit, 3 is a character input unit, 4 is a memory card unit, 5 is a display unit, 6 is an I / F, 7 is a CPU, 8 is a RAM, 9 is a ROM, 10 is a bus

Claims (4)

A file management program for recording each file data using a cluster chain based on the FAT file system,
A file management program for causing a computer to execute a recording function of recording cluster chain information indicating a cluster storing the file data in a file cluster chain item for recording the cluster chain information.   The file management program according to claim 1, which causes a computer to execute an information acquisition function for acquiring the cluster chain information from the file cluster chain item. A file management device for recording each file data using a cluster chain based on the FAT file system,
A file management apparatus comprising: recording means for recording cluster chain information indicating a cluster storing the directory item in a file cluster chain item for recording the cluster chain information.   4. The file management apparatus according to claim 3, further comprising information acquisition means for acquiring the cluster chain information from the file cluster chain item.

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