JP2016024487A - Information processing device, information processing method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processing device capable of obtaining the total value of file sizes at high speed when the total value of the file sizes is necessary while using an existing file system.SOLUTION: An information processing device that manages files for each directory includes: acquisition means that obtains the total value of file sizes of files in the directory; storage means that stores the obtained total value of file sizes in a directory entry of the directory; and reference means that refers to the total size of file sizes from the directory entry.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an information processing apparatus that manages files.

  An information processing apparatus such as a general personal computer or embedded device has a storage device, and can record, edit, copy, and delete electronic files. In a general file system, files are classified and managed for each directory (or folder). In the copy process, a directory may be copied to another storage location (another directory or another storage device). In that case, in order to determine whether or not the copy destination has sufficient free space, it is necessary to calculate the total value of the file sizes of the files in the copy source directory. By comparing the total value with the free capacity of the copy destination, it can be determined whether or not the copy process is possible.

  In many file systems such as a FAT (File Allocation Table) file system employed in an embedded device or the like, it is necessary to calculate the total value of the above-described file sizes every time copy processing is performed. Therefore, as the number of files in the copy source directory increases, the time for calculating the total file size increases. For this reason, in many file systems, the calculation of the total file size is a cause of a decrease in processing speed such as copy processing.

  Patent Document 1 discloses that a file information table storing a total value of file sizes for each directory is created in a storage device in order to prevent the processing speed from being lowered. The total file size stored in the file information table is calculated in advance. Accordingly, when the total value of the file sizes is necessary, it is only necessary to refer to the file information table, and it is possible to prevent the reduction in the processing speed.

JP 2004-21303 A

  In the technique disclosed in Patent Document 1, since it is necessary to newly create a file information table, it may be difficult to adopt it in an existing file system such as a FAT file system. In addition, the file information table may press the storage capacity in the storage device. The present invention has been made in view of the above problems, and provides an information processing apparatus that can easily and quickly refer to the total value of file sizes when the total value of file sizes is required. The purpose is to do.

  The present invention is an information processing apparatus that manages a file for each directory, an acquisition unit that acquires a total value of file sizes of files in the directory, and a total value of the acquired file sizes, Storage means for storing in the directory entry and reference means for referring to the total value of the file sizes from the directory entry are provided.

  According to the present invention, it is possible to provide an information processing apparatus that can easily and quickly refer to a total value of file sizes when the total value of file sizes is required.

The figure which shows the hardware constitutions of information processing apparatus. The figure which shows the structure of the FAT file system in an external storage device. The figure which shows the structure of the directory entry of a FAT file system. The figure which shows the state by which the total value of the file size of the file was memorize | stored in the directory entry 300. The figure which shows the flow which showed the specific process for memorize | storing a total value in the directory entry. The figure which shows the process in the case of creating a file in a directory in 1st embodiment. The figure which shows the process in the case of deleting the file in a directory in 1st embodiment. The figure which shows the process in the case of changing the file size of a file in 1st embodiment. The figure which shows the processing flow in the case of changing the file size of the file in a directory in 1st embodiment. The figure which shows the process in the case of adding a child directory in a parent directory in 2nd embodiment. The figure which shows the process in the case of deleting the child directory in a parent directory in 2nd embodiment. The figure which shows the process in the case of creating (adding) a file in a child directory in 3rd embodiment. The figure which shows the processing flow in the case of creating a file in a child directory in 3rd embodiment. The figure which shows the flow of the subroutine for updating a high-order directory entry in 3rd embodiment. The figure which shows the process in the case of deleting the file in a child directory in 3rd embodiment. The figure which shows the processing flow in the case of deleting the file in a child directory in 3rd embodiment. The figure which shows the process in the case of changing the file size of the file in a child directory in 3rd embodiment. The figure which shows the processing flow in the case of changing the file size of the file in a child directory in 3rd embodiment. The figure which shows the process in the case of creating (adding) a directory in a child directory in 3rd embodiment. The figure which shows the processing flow in the case of creating a file in a child directory in 3rd embodiment. It is a figure which shows the process in the case of deleting the directory in a child directory in 3rd embodiment. The figure which shows the processing flow in the case of deleting the directory in a child directory in 3rd embodiment.

(First embodiment)
FIG. 1 is a diagram illustrating a hardware configuration of a file management apparatus 100 (information processing apparatus) in the present embodiment.

  Each processing is executed in accordance with a processing procedure of a CPU (Central Processing Unit) 101 computer program. A ROM (Read Only Memory) 102 stores computer programs and data. A RAM (Random Access Memory) 103 temporarily stores computer programs, data used for processing, processing results, and the like.

  The external storage device 104 includes an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like. The external storage device 104 stores computer programs, data used for processing, processing results, and the like.

  The bus 105 is a communication path for transmitting and receiving data between the above-described units.

  The CPU 101 transmits and receives various data to and from the ROM 102, RAM 103, and external storage device 104 via the bus 105. Specifically, the CPU 101 reads out a computer program stored in the external storage device 104 or the ROM 102 and stores it in the RAM 103. Then, according to the processing procedure of the read computer program, predetermined data is read from the external storage device 104 and the like, and each processing is performed.

  Note that data and computer programs in the external storage device 104 are managed and stored for each directory as electronic files. As a file storage method, there are various file systems such as a FAT file system and an ext file system. Hereinafter, the structure of a FAT file system, which is one of the file systems, will be described.

  FIG. 2 is a diagram showing the structure of the FAT file system in the external storage device 104 according to this embodiment.

  The boot sector 201 stores partition information of the entire file system. The boot sector 201 stores information indicating the format, the size of a FAT area described later, the size of a data area described later, and the like.

  The FAT area 202 mainly stores information indicating the connection state between clusters. A cluster is a processing unit for reading and writing data in a FAT file system, and is a collection of a plurality of sectors that are storage units of a storage medium. The cluster indicating the actual data of the file is not always stored continuously in the external storage device 104. Therefore, when reading or writing a file, it is necessary to refer to the connection state between clusters based on information in the FAT area 202.

The data area 203 stores actual data and directory entries.
The actual data is data indicating the substance of information in the file. The directory entry is stored for each file and directory, and information indicating the file name and the data size of the file is stored. The structure of the directory entry will be described later. The above is the structure of the FAT file system.

  FIG. 3 is a diagram showing the structure of the directory entry 300 of the FAT file system in the present embodiment.

  The file / directory name 301 is information indicating a file name or a directory name. The attribute 302 is information indicating whether it is a file or a directory, and in the case of a file, it is read-only. A reserved area 303 indicates a reserved area of a file or a directory. The update time 304 is information indicating the update time of the file or directory. The update date 305 is information indicating the update date of the file or directory. Reference numeral 306 denotes the first cluster number 306 of the actual data indicating the first cluster number of the actual data of the file.

  The size area 307 indicates the file size when the directory entry 300 corresponds to a file. As a specific value, the number of bytes of the file size is stored. If the directory entry 300 corresponds to a directory, 0 is normally stored.

  In the present embodiment, when the directory entry 300 corresponds to a directory, the total size of the files in the directory is stored in the size area 307 of the directory entry 300. FIG. 4 is a diagram showing a state where the total value of the file sizes of the files is stored in the directory entry 300. As shown in FIG. 4, the size area 307 stores the size S1 of the file A and the size S2 of the file B. By storing the total value of the file size in the directory entry 300, even if the total value of the file size is required for copying or moving, it is not necessary to calculate the total value again. That is, since the total value of the file sizes can be acquired by referring to the size 307 of the directory entry 300, the processing speed when acquiring the total value of the file sizes can be improved. Therefore, it is possible to determine at high speed whether or not there is a free space necessary for copying or moving at the copy destination or destination. If it is determined that there is not enough free space, a system error is issued and copying or moving is stopped.

FIG. 5 is a flow showing a specific process for storing the total value in the directory entry 300.
In S501, the file management apparatus 100 calculates the total value of the file sizes of the files in each directory when creating a new file system or creating a new directory.

  In addition, when the total value of the file size of the file can be acquired from an external device or the like, it may be acquired from the external device. In S <b> 502, the total file size of the acquired or calculated files is stored in the size 307 of the directory entry 300. After the total value of the file size is stored by the above processing, the total value of the file size can be acquired by referring to the directory entry 300 when necessary.

  In the following, processing in the present embodiment when file creation / deletion, file size change, and the like are performed will be described.

(Create file)
Processing when the file management apparatus 100 creates a file in a predetermined directory will be described.

  FIG. 6A is a conceptual diagram showing processing when a file is created in a directory. Here, it is assumed that the file management apparatus 100 creates a file 402 of size S1 in the directory 401. The left part of FIG. 6A shows a state before the file is created and no file exists in the directory 401. Since no file exists in the directory 401, 0 is stored in the size area 307 of the directory entry 300. Here, when a new file is created in the directory, the value of the directory entry 300 is changed as in the right part. As illustrated, the file size S1 of the newly created file 402 is stored in the size area 307 of the directory entry 300. By such processing, the total value of the file sizes of the files in the directory is stored in the size area 307 of the directory entry 300.

  Next, a specific processing flow for creating a file in a directory in order to realize the above processing will be described.

  FIG. 6B is a diagram showing a processing flow when a file is created in a directory. Each process will be described with reference to FIG. 6A as an example.

  In step S <b> 501, the file management apparatus 100 acquires a total of 0 file sizes stored in the size area 307 of the directory entry 300 corresponding to the directory 401. In step S502, the file management apparatus 100 acquires the size S1 stored in the size area 307 of the directory entry 300 corresponding to the file 402 to be created. In step S503, the file management apparatus 100 adds the size S1 acquired in step S501 and the size 0 acquired in step S502. In step S504, the file management apparatus 100 stores the size S1 acquired in step S503 in the size area 307 of the directory entry 300 corresponding to the directory 401. The above is the file creation processing in the present embodiment. FIG. 6A shows a case where only one file is created, but even when a plurality of files are created, processing can be similarly performed according to the processing flow of FIG.

(Delete file)
Processing when the file management apparatus 100 deletes a file in a predetermined directory will be described. FIG. 7A is a conceptual diagram showing processing when a file in a directory is deleted.

  Here, it is assumed that the file management apparatus 100 deletes the file 602 in the directory 601. The left part of FIG. 7A shows a state before file deletion. In the size area 307 of the directory entry of the directory 601, the file size S1 is stored. Here, when a file in the directory is deleted, the value of the directory entry is changed as shown on the right side. As shown in the figure, since the file is deleted and no file exists in the directory, 0 is stored in the size 307 of the directory entry.

  Next, a specific processing flow for deleting a file in the directory in order to realize the above processing will be described.

  FIG. 7B is a diagram showing a processing flow when deleting a file in a directory. Each process will be described with reference to FIG. 7A as an example. In step S <b> 701, the file management apparatus 100 acquires the total file size S <b> 1 stored in the size area 307 of the directory entry 300 corresponding to the directory 601. In step S702, the file management apparatus 100 acquires the size S1 stored in the size area 307 of the directory entry 300 corresponding to the file 602 to be deleted. In step S703, the file management apparatus 100 subtracts the size S1 acquired in step S702 from the size S1 acquired in step S701. In this case, the size is 0. In step S704, the file management apparatus 100 stores the size 0 acquired in step S703 in the size area 307 of the directory entry 300 corresponding to the directory 601.

  The above is the file deletion process in the present embodiment. Although FIG. 7A shows a case where only one file is deleted, even when a plurality of files are deleted, processing can be similarly performed according to the processing flow of FIG.

(Change file size)
Processing when the file management apparatus 100 changes the file size of a file in a predetermined directory will be described. FIG. 8 is a conceptual diagram showing processing when changing the file size in the directory.

  Here, it is assumed that the file management apparatus 100 changes the file size of the file 802 in the directory 801. The left part of FIG. 8 shows a state before the file size is changed. In the size area 307 of the directory entry 300 of the directory 801, the file size S1 is stored. Here, when the file size of the file 802 in the directory is changed, the value of the directory entry 300 is changed as in the right part. As shown in the figure, since the file size of the file has been changed, the changed size S1 'is stored in the size area 307 of the directory entry 300.

  Next, a specific processing flow for changing the file size of a file in the directory in order to realize the above processing will be described.

  FIG. 9 is a diagram showing a processing flow when changing the file size of a file in the directory. Each process will be described with reference to FIG.

  (S901) In step S901, the file management apparatus 100 acquires the total S1 of file sizes stored in the size area 307 of the directory entry 300 corresponding to the directory 801. In step S902, the file management apparatus 100 acquires the size S1 from the size area 307 of the directory entry 300 corresponding to the file 802 before the size change. In step S903, the file management apparatus 100 acquires the size S1 'from the size area 307 of the directory entry 300 corresponding to the file 802 after the size change. In step S904, the file management apparatus 100 subtracts the size S1 acquired in step S902 from the size S1 'acquired in step S903. In step S905, the file management apparatus 100 adds the difference (S1'-S1) acquired in step S904 to the total file size S1 acquired in step S901. In step S906, the file management apparatus 100 stores the size S1 'acquired in step S905 in the size area 307 of the directory entry 300 corresponding to the directory 801.

  The above is the file deletion process in the present embodiment. Note that FIG. 8 shows a case where only one file size is changed. However, even when the file size of a plurality of files is changed, processing can be similarly performed according to the processing flow of FIG. It is.

  With the above processing, in the present embodiment, the total value of the file size can be reflected in the directory entry of the directory when creating, deleting, and changing the file. Therefore, when it becomes necessary to obtain the total value of the file sizes of the files included in the directory, there is no need to perform the total processing again, and the total value of the file sizes can be quickly determined by referring to the directory entry of the directory. Can be acquired. Further, since the directory entry is used, the method of the present embodiment can be easily implemented in a general file system.

(Second embodiment)
In the first embodiment, the processing when only a file exists in the directory has been described. In the present embodiment, a process when another directory exists in the directory will be described. Note that file creation, file deletion, and file size change processing are the same as those in the first embodiment, and thus description thereof is omitted here. In this embodiment, the upper hierarchy directory is a parent directory, and the lower hierarchy directory is a child directory.

(Add directory)
FIG. 10 is a diagram illustrating processing when a child directory is added to a parent directory in the present embodiment.

  The left part of FIG. 10 shows a state where a file 1002 of size S1 exists in the directory 1001. In the size area 307 of the directory entry 300 corresponding to the directory 1001, the total file size S1 is stored. Here, it is assumed that the file management apparatus 100 adds a directory 1003 having a total file size S2 to the directory 1001 as shown in the right part of FIG. In this embodiment, when the parent directory has a child directory, the total file size of the child directory is not added to the total file size of the parent directory. Therefore, even if the directory 1003 is added to the directory 1001, the total file size of the size area 307 of the directory entry 300 corresponding to the directory 1001 is not changed from S1.

(Delete directory)
FIG. 11 is a diagram showing processing when deleting a child directory in the parent directory in the present embodiment.

  The left part of FIG. 11 shows a state in which a directory 1101 has a file 1102 of size S1 and a directory 1103 having a total file size S2. The total file size S1 is stored in the size area 307 of the directory entry 300 corresponding to the directory 1101. Here, as shown in the right part of FIG. 11, it is assumed that the file management apparatus 100 deletes the directory 1103 under the directory 1101. However, in this embodiment, the total file size of the child directories is not added to the total file size of the parent directory, similar to the addition of the directory. Therefore, even if the directory 1103 is deleted from the directory 1101, the total file size of the directory 1101 is not changed from S1.

  When the processing in this embodiment is performed, the total value of the file sizes in the child directory is not reflected in the total value of the file sizes in the parent directory. Therefore, when a total value including the total value of the file sizes in the child directory is necessary, the total processing is sequentially required. However, since the total file size of the parent directory is not changed according to the addition / deletion of the child directory, the processing speed of the entire system can be improved when adding / deleting the child directory frequently. It becomes.

(Third embodiment)
In the second embodiment, the total file size of the parent directory is not reflected in the total file size of the parent directory. In this embodiment, the total value of the file sizes of the child directories is reflected in the total value of the file sizes of the parent directory. In this embodiment, the total value of the file sizes of the child directories is reflected up to the root directory that is the highest directory.

(Create file)
FIG. 12 is a diagram showing processing when a file is created (added) in a child directory in the present embodiment. The left part of FIG. 12 shows the state before file creation, and the right part of FIG. 12 shows the state after file creation. As shown in the figure, a child directory 1202 exists in the parent directory 1201 and a file 1203 exists in the child directory 1202 before file creation. In the size area 307 of the directory entry 300 of each of the parent directory 1201 and the child directory 1202, the file size S1 of the file 1203 is stored.

  After the file is created, a file 1204 is created in the child directory 1202 in addition to the file 1203. In the size area 307 of the directory entry 300 of each of the parent directory 1201 and the child directory 1202, the total value of the file size S1 of the file 1203 and the size S2 of the file 1204 is stored.

  Next, a processing flow when creating a file in a child directory in the present embodiment will be described. FIG. 13 is a diagram showing a processing flow when a file is created in a child directory in the present embodiment. Each process will be described with reference to FIG.

  In step S1301, the file management apparatus 100 acquires the total file size S1 stored in the size area 307 of the directory entry 300 corresponding to the child directory 1202. In step S1302, when the file 1204 is created in the child directory 1202, the file management apparatus 100 acquires a size S2 that is the file size of the file 1204. In step S1303, the file management apparatus 100 adds the size S1 acquired in step S1301 and the size S2 acquired in step S1302. In step S1304, the file management apparatus 100 stores the size (S1 + S2) acquired in step S1303 in the size area 307 of the directory entry 300 corresponding to the directory 1202. In step S1305, the file management apparatus 100 updates the directory entry 300 of the directory above the directory in which the directory entry 300 has been updated. However, the update in this step is executed using a subroutine. Specific processing of the subroutine will be described with reference to the flowchart of FIG.

  Next, specific processing of the subroutine in step S1305 will be described. FIG. 14 is a flowchart illustrating a subroutine for updating the upper directory entry 300. Each process will be described with reference to FIG. In the following subroutine, for convenience, the directory 1202 in which the total file size is updated in the immediately preceding step is set as the current directory (the directory in which the file management apparatus 100 updates the total file size at the current time).

  In step S1401, the file management apparatus 100 sets the directory updated immediately before starting the subroutine processing as the current directory. When this subroutine is started from the flow of FIG. 13, the directory 1202 becomes the current directory. In step S1402, the file management apparatus 100 determines whether or not the current directory is the root directory (the highest directory). If it is determined that the directory is the root directory, there is no upper directory to be updated, and the subroutine is terminated. If it is not determined that the directory is the root directory, the process advances to step S1403. In step S1403, the file management apparatus 100 updates the current directory to an upper directory. When this subroutine is started from the flow of FIG. 13, the directory 1201 that is one directory higher than the directory 1202 is set as the current directory. In step S1404, the file management apparatus 100 acquires a value stored in the size area 307 of the directory entry 300 corresponding to the current directory. When this subroutine is started from the flow of FIG. 13, the total file size S1 is acquired from the size area 307 of the directory entry 300 corresponding to the current directory 1201. In step S1405, the file management apparatus 100 acquires the total file size before the change of the directory one level lower than the current directory. When this subroutine is started from the flow of FIG. 13, the total value S1 of the file sizes before the change of the child directory 1202 of the current directory 1201 is acquired. It is assumed that the total file size S1 before update is stored in advance in a memory buffer or the like. In step S1406, the file management apparatus 100 acquires the total file size after the change of the directory one level lower than the current directory. When this subroutine is started from the flow of FIG. 13, the total value (S1 + S2) of the file size after the change of the child directory 1202 of the current directory 1201 is acquired. In step S1407, the file management apparatus 100 subtracts the total value of file sizes acquired in step S1405 from the total value of file sizes acquired in step S1406. When this subroutine is started from the flow of FIG. 13, the total file size value S1 acquired in step S1405 is subtracted from the total file size value (S1 + S2). In step S1408, the file management apparatus 100 adds the difference acquired in step S1407 and the file size acquired in step S1404. When this subroutine is started from the flow of FIG. 13, the difference S2 acquired in step S1407 and the file size S1 acquired in step S1404 are added. In step S1409, the file management apparatus 100 stores the value acquired by the addition in step S1408 in the size area 307 of the directory entry 300 corresponding to the current directory. When this subroutine is started from the flow of FIG. 13, the value (S1 + S2) acquired in step S1408 is stored in the size area 307 of the directory entry 300 corresponding to the current directory 1201. After the process of step S1409, the process returns to step S1402, and the above process is repeated until it is determined in step S1402 that the current directory is the root directory.

  By the above processing, the total value of the file sizes of the child directories can be reflected up to the root directory which is the highest directory.

  In step S1402 of FIG. 14, it is determined whether or not to end the subroutine based on the determination result of whether or not the current directory is the root directory. However, instead of the root directory, it may be determined whether or not to end the subroutine based on the determination result of whether or not the current directory is a directory specified in the file management apparatus 100.

(Delete file)
FIG. 15 is a diagram showing processing when deleting a file in a child directory in the present embodiment. The left part of FIG. 15 shows the state before file deletion, and the right part of FIG. 15 shows the state after file deletion. As illustrated, before the file is deleted, a child directory 1502 exists in the parent directory 1501, and a file 1503 and a file 1504 exist in the child directory 1502. In the size area 307 of the directory entry 300 of each of the parent directory 1501 and the child directory 1502, the total value of the file size S1 of the file 1503 and the file size S2 of the file 1504 is stored.

  After the file is deleted, the file 1504 is deleted from the child directory 1502, and only the file 1503 exists. Only the file size S1 of the file 1503 is stored in the size area 307 of the directory entry 300 of each of the parent directory 1501 and the child directory 1502.

  Next, a processing flow when deleting a file in the child directory in the present embodiment will be described. FIG. 16 is a diagram showing a processing flow when deleting a file in a child directory in the present embodiment. Each process will be described with reference to FIG.

  In step S1601, the file management apparatus 100 acquires the total file size (S1 + S2) stored in the size area 307 of the directory entry 300 corresponding to the child directory 1502. In step S1602, when the file 1504 is deleted from the child directory 1502, the file management apparatus 100 acquires the size S2 that is the file size of the file 1504. In step S1603, the file management apparatus 100 subtracts the file size S2 acquired in step S1602 from the total file size (S1 + S2) acquired in step S1601. In step S1604, the file management apparatus 100 stores the difference S1 acquired in step S1603 in the size area 307 of the directory entry 300 corresponding to the directory 1502. In step S1605, the file management apparatus 100 updates the directory entry 300 of the directory that is higher in the directory where the directory entry 300 is updated. The update in this step is executed using the subroutine shown in FIG.

(Change file size)
FIG. 17 is a diagram showing processing when the file size of a file in a child directory is changed in the present embodiment. The left part of FIG. 17 shows the state before changing the file size, and the right part of FIG. 17 shows the state after changing the file size. As illustrated, before the file size is changed, a child directory 1702 exists in the parent directory 1701 and a file 1703 exists in the child directory 1702. In the size area 307 of the directory entry 300 of each of the parent directory 1701 and the child directory 1702, the file size S1 of the file 1703 is stored.

  After the file size change, the file size S1 'of the file 1703 after the file size change is stored in the size area 307 of the directory entry 300 of each of the parent directory 1701 and the child directory 1702.

  Next, a processing flow when changing the file size of a file in a child directory in the present embodiment will be described. FIG. 18 is a diagram showing a processing flow when changing the file size of a file in the child directory in the present embodiment. Each process will be described with reference to FIG. In step S1801, the file management apparatus 100 acquires the total file size S1 stored in the size area 307 of the directory entry 300 corresponding to the child directory 1702. In step S1802, when changing the file size of the file 1703, the file management apparatus 100 acquires S1 that is the file size of the file 1703 before the file size change. In step S1803, the file management apparatus 100 acquires S1 'that is the file size of the file 1703 after the file size change. In step S1804, the file management apparatus 100 subtracts the file size S1 acquired in step S1803 from the file size S1 ′ acquired in step S1803 to acquire a difference value. In step S1805, the file management apparatus 100 adds the difference value acquired in step S1804 to the total file size S1 acquired in step S1801. In step S1806, the file management apparatus 100 stores the value acquired in step S1805 in the size area 307 of the directory entry 300 corresponding to the child directory 1702.

  (S1807) In step S1807, the file management apparatus 100 updates the directory entry 300 of the directory that is above the directory in which the directory entry 300 is updated. The update in this step is executed using the subroutine shown in FIG.

(Add directory)
FIG. 19 is a diagram showing processing when a directory is created (added) in a child directory in the present embodiment. The left part of FIG. 19 shows the state before directory creation, and the right part of FIG. 19 shows the state after directory creation. As shown in the figure, a child directory 1902 exists in the parent directory 1901 and a file 1903 exists in the child directory 1902 before directory creation. In the size area 307 of the directory entry 300 of each of the parent directory 1901 and the child directory 1902, the file size S1 of the file 1903 is stored.

  After the directory is created, a directory 1904 is created in addition to the file 1903 in the child directory 1902. In the size area 307 of the directory entry 300 of each of the parent directory 1901 and the child directory 1902, the total value of the file size S1 of the file 1903 and the size S2 of the directory 1904 is stored.

  Next, a processing flow when a directory is created in a child directory in the present embodiment will be described. FIG. 20 is a diagram showing a processing flow when a file is created in a child directory in the present embodiment. Each process will be described with reference to FIG. 19 using FIG. 19 as an example.

  In step S2001, the file management apparatus 100 acquires the total file size S1 stored in the size area 307 of the directory entry 300 corresponding to the child directory 1902. In step S2002, when the directory 1904 is created in the child directory 1902, the file management apparatus 100 acquires a size S2 that is the directory size of the directory 1904. In step S2003, the file management apparatus 100 adds the size S1 acquired in step S2001 and the size S2 acquired in step S2002. In step S2004, the file management apparatus 100 stores the size (S1 + S2) acquired in step S2003 in the size area 307 of the directory entry 300 corresponding to the directory 1902. In step S2005, the file management apparatus 100 updates the directory entry 300 of the directory above the directory in which the directory entry 300 is updated. The update in this step is performed using the subroutine shown in FIG.

(Delete directory)
FIG. 21 is a diagram showing processing when a directory in a child directory is deleted in the present embodiment. The left part of FIG. 21 shows the state before directory deletion, and the right part of FIG. 21 shows the state after directory deletion. As shown in the figure, before directory deletion, a child directory 2102 exists in the parent directory 2101, and a file 2103 and a directory 2104 exist in the child directory 2102. In the size area 307 of the directory entry 300 of each of the parent directory 2101 and the child directory 2102, the total value of the file size S1 of the file 2103 and the directory size S2 of the directory 2104 is stored.

  After the directory is deleted, the directory 2104 is deleted from the child directory 2102 and only the file 2103 exists. Only the file size S1 of the file 2103 is stored in the size area 307 of the directory entry 300 of each of the parent directory 2101 and the child directory 2102.

  Next, a processing flow for deleting a directory in a child directory in this embodiment will be described. FIG. 22 is a diagram showing a processing flow when a directory in a child directory is deleted in the present embodiment. Each process will be described with reference to FIG.

  In step S2201, the file management apparatus 100 acquires the total file size (S1 + S2) stored in the size area 307 of the directory entry 300 corresponding to the child directory 1502. In step S2202, when the directory 2104 is deleted from the child directory 1502, the file management apparatus 100 acquires a size S2 that is the directory size of the directory 2104. In step S2203, the file management apparatus 100 subtracts the directory size S2 acquired in step S2202 from the total file size (S1 + S2) acquired in step S2201. In step S2204, the file management apparatus 100 stores the difference S1 acquired in step S2203 in the size area 307 of the directory entry 300 corresponding to the directory 2102. In step S2205, the file management apparatus 100 updates the directory entry 300 of the directory above the directory in which the directory entry 300 has been updated. The update in this step is executed using the subroutine shown in FIG.

  Through the above processing, in this embodiment, the total value of the file sizes of the child directories can be reflected up to the root directory which is the highest directory. Therefore, when it is necessary to obtain the total value of the file sizes of all the files contained in the directory, there is no need to perform the total process again, and the total value of the file sizes can be obtained at high speed by referring to the directory entry of the directory. Can be obtained. Further, since the directory entry is used, the method of the present embodiment can be easily implemented in a general file system.

  In the present embodiment, the total value of the file sizes of the files is calculated based on the total value of the file sizes stored in the directory entry of the child directory. However, the file sizes of all the files may be summed and the total value may be stored in the directory entry of the root directory without referring to the directory entry of the child directory.

  In the above embodiment, the description has been made on the assumption of the structure of the FAT file system that is often used in embedded devices and the like. However, the present embodiment is not limited to the information processing apparatus using the FAT file system, and other file systems such as an ext file system can be used.

(Other embodiments)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

200 External Storage Device 201 Boot Sector 202 FAT Area 203 Data Area 300 Directory Entry 301 File / Directory Name

Claims (9)

An information processing apparatus that manages files for each directory,
Calculating means for calculating a total value of file sizes of files in the directory;
Storage means for storing the total value of the calculated file sizes in a directory entry of the directory;
Reference means for referring to the total value of the file sizes from the directory entry;
An information processing apparatus comprising:   The information processing apparatus according to claim 1, wherein the calculation unit calculates a total value of the file sizes when the directory is created.   Change means for changing a total value of the file sizes stored in the directory entry when creating a file in the directory, deleting a file from the directory, or changing the file size of the file in the directory. The information processing apparatus according to claim 1, further comprising:   The said change means changes the total value of the said file size memorize | stored in the said directory entry, when creating a subordinate directory in the said directory or deleting a subordinate directory from the said directory. Item 4. The information processing device according to Item 3.   The information processing apparatus according to claim 1, wherein the calculation unit adds the file sizes of the files in the directory and calculates a total value of the file sizes.   The calculation means calculates the total value of the file sizes by adding the values stored in the directory entries of the lower directories in the directory and the file sizes of the files in the directory. The information processing apparatus according to claim 1.   When copying or moving the directory, based on the total value of the file sizes referred to by the referring means from the directory entry of the directory, whether there is a free space necessary for copying or moving at the copy destination or destination The information processing apparatus according to claim 1, further comprising determination means for determining whether or not. An information processing method for managing files for each directory,
An obtaining step in which an obtaining unit obtains a total value of file sizes of files in the directory;
A storage step of storing, in a storage means, the total value of the acquired file sizes in a directory entry of the directory;
An information processing method comprising: a reference step of referring to the total value of the file sizes from the directory entry. Computer
An information processing apparatus that manages files for each directory,
Obtaining means for obtaining a total value of file sizes of the files in the directory;
Storage means for storing the total value of the acquired file sizes in a directory entry of the directory;
Reference means for referring to the total value of the file sizes from the directory entry;
A computer program that functions as an information processing apparatus.

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