JP2001043662A - Disk medium managing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten time required for a seek or the like and also to estimate the worst time of seek required for reading or writing of data by enabling the data to be continuously accessed as much as possible at the time of reading the data from a disk or writing the data to the disk. SOLUTION: At time of recording a data file on a disk, in a continuous arrangement mode, this method secures continuous areas having arbitrary sizes without performing the recording of data actually and manages even as to unsused parts with numbers of divisions and positional information in those areas. Recording orders of the positional information are recorded in orders to be read out from the disk for every division being used and unused divisions are recorded in the order of the increasing of sizes behind them. In the file in which the continuous areas are secured, since the recording positions on the desk are limited in the areas, an unnecessary seek due to that other data coexist in the same area at the time of reading the data from the disk is not generated and access time can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk medium management method for a disk device for recording and reproducing data, and more particularly to a method for securing a continuous area on a disk medium for one file in advance and using the area within the area. The present invention relates to a management method suitable for use in, for example, a video camera apparatus using a disk as a recording medium, which can manage the situation.

[0002]

2. Description of the Related Art When data is recorded on a disk, management information for managing where the recorded data is recorded on the disk is required. For this reason, MS-DOS and Wi-Fi are widely used to provide management methods.
JIS X0605- used in Windows etc.
1990, OSTA (Optical Storage Technology Associati) commonly used in FAT systems and DVDs
on) UDF, etc., and are called logical standards for disks. By using these logical standards, it is possible to determine, by the file name, where the data corresponding to the file is recorded on the disc. Also, since the directory concept is defined,
It is possible to express a hierarchical structure.

FIG. 15 is a schematic diagram showing the relationship between management information in MS-DOS and data on a disk. MS-
FA, a file management method used in DOS, etc.
In the T system, each directory has a management descriptor called a directory entry, and this descriptor manages files and directories existing in the directory.
32 bytes of information are recorded for each file or directory. In the 32 bytes, the file name, file name extension, file attribute, last edit time, last edit date,
The starting cluster and file size are recorded.

When a data file is managed, a starting cluster number and a file size at which data is actually recorded are recorded. Information on how the data is actually recorded on the disc is obtained by referring to the FAT. FAT means, for example, 16-bit information for each cluster on the disk, records the cluster number to be accessed next in this 16-bit information, and is the last cluster for forming a series of files. Contains information to indicate that it is the last (0
xFFFF). That is, the start position cluster number of the data recorded on the disk is known from the management descriptor, and the FAT is used to read the data from the disk.
It is only necessary to trace the cluster number to be read next and managed until 0xFFFF appears.

FIG. 16 is a schematic diagram showing management information in the UDF. To explain only the part that controls where the file is recorded on the disk,
In UDF, position information where data is recorded is recorded in a file entry (File Entry). The position information is performed in units of continuous recording, and when divided and recorded on the disc, management is performed for each division. For the management of the disk usage status, a space bitmap (Space Bitmap) shown in FIG. 9 described later may be used.

[0006]

When data is recorded on a disk medium, a program such as a program or an image, as shown in FIG.
File 1 of a unit of data (File
Even in the case of 1), the file 1-1 need not be continuously arranged on the disk, but may be divided into various locations on the disk.
(File1-1), File1-2 (File1-
2), it is possible to record such as file 1-3 (File 1-3). However, for example, when reading data from a disk, if it is said that data must be read within a certain period of time, or if data is read out and updated frequently, the time for extra seeks etc. will be reduced as much as possible. In some cases, it is preferable to arrange data continuously from the viewpoint of processing speed. Further, in a state where data can be written anywhere on the disk, it is difficult to estimate an access time for actually recording or reproducing data.

For example, when video data compressed by an MPEG encoder or the like is recorded on a disk, it is necessary to record the recorded data in consideration of the case where the recorded data is reproduced. That is, it is necessary to read out the video data arranged in time series from the disk within a predetermined time, decode the data with an MPEG decoder, and reproduce the video. If the processing is not completed within a predetermined time, the video stops in the reproduced image or the image becomes unnatural.
One solution to prevent this is to provide a buffer memory for temporarily storing an MPEG video stream read from a disk before performing MPEG decoding. By storing a certain amount of data in this buffer memory, the reading of data from the disk due to a loss of servo synchronization due to an external shock or a seek to read the recorded data that has been divided is temporarily stopped. Will be able to cope with the situation. However, the allowable time of reading interruption from this disk is determined according to the capacity of the buffer memory, but if a lot of memory has some effect, if reading interruption from the disk such as seek occurs continuously and frequently, There is a high possibility that the seamlessness in which the video is reproduced in time series cannot be achieved. Also, in order to extend the permissible time during which reading from the disk is interrupted, it is necessary to store more data in the buffer memory.For example, when performing playback, data must be stored for a certain period of time after starting playback. Since it has to be used to accumulate, video output cannot be obtained during that period, which is problematic.

When the data to be recorded on the disk is only video data, if the data is sequentially recorded from the beginning of the disk, the data is continuously recorded on the disk. Actually, it is conceivable that various types of data such as still images, audio, management information, and programs are mixed on the same disk. Under such an environment, different types of data such as still images and sounds may be arranged after the position of the video data already recorded on the disc. As a result, the video data is discontinuously arranged on the disk. When reproducing discontinuously arranged video data, continuous data cannot be read, and a seek occurs on the way, and the flow of data into the buffer memory temporarily stops. As described above, it is not preferable to arrange the data such that the seek frequently occurs during the reading.

Therefore, by providing a mechanism for securing an area in advance for data to be recorded and guaranteeing a continuous arrangement on the disk, a seek operation during reading due to the presence of other data in the same area is provided. It is conceivable to minimize the occurrence.

In order to realize this, it is necessary to secure a continuous area of a certain size in advance for data even when data is not actually recorded. In addition, it is necessary to know which part has already been used and which part has not been used in the continuously secured area.

In the above-mentioned conventional FAT system, if a continuous area for recording data is to be reserved in advance, the FA corresponding to the continuous area is required.
It is necessary to set T to a use state. As a result, since the continuous area is in use, there is no fear that the area is used for another file. However, since there is no information on which part is used and which part is not used in the continuously secured area, for example, a management file for recording the usage status is stored on the disk. It needs to be created separately above.

In the above-mentioned UDF of the prior art, if a continuous area for recording data is to be secured in advance, a file extent (File Exten
t) manages the continuously secured area and manages the space bitmap (Space Bitm) corresponding to the secured continuous area.
ap) must be set to use. As in the case of FAT, the secured continuous area is in use, so there is no need to worry about using that area for other files.
It is not possible to obtain information as to which part of the secured continuous area is used and which part is not used from the management information at the logical level.

As described above, in the conventional management method, it is possible to secure a continuous area in advance, but there is a problem that it is difficult to actually manage the use status in the continuous area. .

The present invention has been proposed in view of the above-mentioned problems, and it is possible to reserve a continuous area on a disk for one file in advance, and at the same time, manage the use status in the continuously secured area. The purpose is to provide a management method.

It is another object of the present invention to provide a disk device management method capable of writing data to a disk and predicting an access time for reading data from the disk to some extent because the area where data is arranged can be limited. .

[0016]

SUMMARY OF THE INVENTION The present invention provides means for solving such a problem, and the invention of each claim has the following features. 2. The disk medium management method according to claim 1, wherein in the disk medium management method for managing data recorded on the disk medium in a file format, one data file is recorded without actually recording the data. It is characterized in that a continuous area of an arbitrary size is secured on the upper side, and the use status in the continuous area is also managed.

According to a second aspect of the present invention, in the disk medium management method according to the first aspect, only a portion used as a use status is managed in the continuously secured area.

According to a third aspect of the present invention, in the disk medium management method according to the first aspect, only a part which is not used as a use status is managed in the continuously secured area.

According to a fourth aspect of the present invention, in the disk medium management method according to the first aspect, in the continuously secured area, both a part used and a part not used as a use status are managed.

According to a fifth aspect of the present invention, in the disk medium management method of the first aspect, it is possible to switch between securing a continuous area for one data file and not securing a continuous area. Features.

According to a sixth aspect of the present invention, there is provided the disk medium management method according to the first aspect, further comprising means for calculating a maximum seek time when seeking in the continuous area.

According to a seventh aspect of the present invention, there is provided the disk medium management method according to the first aspect, wherein a maximum allowable seek time for seeking in a continuous area to be secured is designated. A means for calculating a region on a disk medium satisfying the following.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk medium management method according to the present invention will be described with reference to the embodiments shown in FIGS. In the disk, logical addresses are sequentially assigned from 0 to the minimum unit of logical read / write for an area in which data can be actually written, excluding a parity and an alternative area when a disk has a defect. The address at this time is called a logical block number, and the size of this logical block is called a logical block size.
The disk usage status is managed for each logical block. Hereinafter, LBN means a logical block number, and unless otherwise specified, an area on a disk refers to an area in which data with a logical block number can be read and written. In this area, management information for managing a data file to be recorded and the like and actual data are recorded.

As the management information recorded in the disk area, a basic volume descriptor for storing basic information of the disk, a space bitmap for managing the use status of the disk, a directory descriptor for managing the directory, and a file description for managing the file A child is provided.

FIG. 4 shows an example of the contents of the basic volume descriptor. For example, the basic volume descriptor records the volume name, volume size, creation date and time, space bitmap of this disk, and a pointer to the root directory descriptor. Here, the pointer to the descriptor means the logical block number LBN in which the descriptor is recorded.

FIG. 9 shows a space bit map (Space Bitm).
The outline of ap) is shown below. The space bitmap gives 1-bit information to all logical blocks on the disk, and when the 1 bit is 0, the logical block is unused and when it is 1, it indicates that the logical block is used. Is to manage. Since each bit of the space bitmap has a one-to-one correspondence with a logical block number, it is possible to know which logical block is used or not used by a calculation formula.

FIG. 5 shows an example of the contents of the directory descriptor. For example, the directory descriptor manages the name of the directory, date and time information about when it was created, the number of file descriptors and directory descriptors of files stored under the defined directory, and their location information. You. Here, the position information means a logical block number in which the descriptor is recorded. Also, the position information exists in the number represented by the number of descriptors.

FIG. 6 shows an example of the contents of the file descriptor. The file descriptor includes the name of the file, date and time information of when the file was created, file size, continuous arrangement attribute, continuous area position information, and division information that manages where the file data is actually recorded on the disk. Record number and location information. The position information exists by the number represented by the number of divisions.

As an initial state, a basic volume descriptor, a space bitmap, and a directory descriptor for a root directory exist in the disk area.
For example, a description will be given of a normal process of writing a certain data on a disk and creating a file.

FIG. 2 shows a flow of processing when a data write request occurs. First, when a file creation request is generated in step 10, it is determined in step 11 whether the continuous arrangement mode is set. In this case, since the mode is the normal mode, an empty area on the disk is searched from the space bitmap based on the size of the data to be recorded in step 13, and the position to write the data is determined. At this time, if a continuous area for the size of the data to be recorded cannot be secured, a divided area on the disc is secured and used as a writing position. If there is no free space on the disc for the size of the data you want to write,
At step 16, error processing is performed.

After data is actually written at this position in step 14, a file descriptor shown in FIG. 6 for managing this file is written to the disk in step 15. This file descriptor records the name of the written data, the continuous arrangement attribute, the date and time of creation, and the position information on the disc. The position information indicates the starting logical block number of the division and the number of blocks as shown in FIG.
Expressed by byte information. At this time, b31, which is the most significant bit of the start logical block number, is set to Reserved, and usually has to be 0. Next, the space bitmap corresponding to the area in which the data is written is updated to the use state. Then, the logical block number in which the file descriptor is recorded is added to the directory descriptor including the written data. If a file is created under the root directory, a logical block number in which the file descriptor of the created file is recorded is added to a directory descriptor for managing the root directory.

FIG. 3 shows a flow of processing when a data read request occurs. First, when a file read request occurs in step 20, it is determined in step 21 whether the continuous arrangement mode is set.
In this case, since the mode is the normal mode, the file descriptor of the target data is searched from the file name specified in step 23. Since the location of the data on the disc can be known from the retrieved file descriptor, the data is read from the disc in step 24 based on the information.

In general, taking advantage of the random access property of a disc, it is not necessary that data of a single unit such as a program be continuously arranged on the disc, but recorded at various positions on the disc. No problem. In such a case, the head of the disk drive seeks the target address every time a non-contiguous portion is accessed, and a rotation wait or the like occurs. When reading data from the disk, first specify the target address and the data length to be read, but if the data to be read is scattered on the disk, issue a read command from the disk every time in non-contiguous parts. The need arises. From such a viewpoint, when it is desired to read data in as short a time as possible, it is important to arrange the data to be read continuously so as to minimize seek and rotation wait. Therefore, means for securing a continuous area as management information and managing the state thereof is provided. Further, since the recording position of the data to be written as a file can be limited to a continuous area where the area is secured, a more realistic access time can be guaranteed based on the worst access time in that area. .

When means for calculating the maximum seek time when seeking in the secured continuous area is used (claim 6),
The maximum seek time when the head of the disk drive seeks the target address can be obtained. The maximum seek time is the worst value of the seek time of the head of the disk drive within the secured area. For example, this information is written when a certain writing or reading is performed between two points physically farthest apart in the area, and the next writing or reading point is the end point while being at the starting point. Or the time during which reading is interrupted. Knowing this time has the merit that, for example, control when reading / writing data that requires real-time properties becomes easy.

When a maximum seek time for seeking in a continuous area to be secured is specified (claim 7), means for calculating an area on a disk medium satisfying the maximum seek time is used. By giving the maximum seek allowable time when the head of the disk drive seeks the target address, an area on the disk that satisfies the maximum seek allowable time can be obtained. By knowing the area that satisfies the maximum seek allowable time,
For example, there is an advantage that control when reading and writing data that requires real-time properties becomes easy. For example, assuming that the maximum seek allowable time is 0.5 seconds, the seek time immediately after the data division point on the disk is 0.5 seconds or less, regardless of the arrangement of a series of data in the area. Is guaranteed to be.

A description will be given of the file descriptor related to the continuous area reservation. The file descriptor has a continuous arrangement attribute indicating whether or not to secure a continuous area. FIG. 7 shows management information relating to the continuous arrangement attribute. Four types of modes are prepared for the continuous arrangement attribute. "Normal mode" in which continuous area is not secured, "Continuous allocation mode (use)" in which continuous area is secured and used parts in that area are managed, and unused areas in that area are secured in continuous area mode There are four “continuous placement modes (unused)” for managing and a “continuous placement mode (used / unused)” for securing a continuous area and managing both used and unused parts in the area. The information managed by the number of divisions in the file descriptor and the position information differs depending on the four modes.

FIG. 11 shows the relationship between management information and data on the disk in the "normal mode". In the case of the “normal mode”, the division number and the position information are used when the file is divided and recorded on the disc. The recording order of the position information must be recorded in the order of reading data from the disk in order to constitute one file. The free area in the figure is an empty area on the space bitmap, and means an area where another file can be recorded.

FIG. 12 shows the relationship between the management information and the data on the disk in the case of the "continuous arrangement mode (use)". In the “continuous arrangement mode (use)”, the use status in the continuously secured area is managed by the number of divisions and the position information. The number of divisions in this case manages the number of divisions of a portion already used in the area. The recording order of the position information needs to be recorded in the order of reading from the disk every division as in the “normal mode”. For the unused part, from the continuously secured area,
It is determined by subtracting the part used. The unused area in the figure means an area which is managed as a used block on the space bitmap and in which other files cannot be recorded.

FIG. 13 shows the relationship between the management information and the data on the disk in the case of the "continuous arrangement mode (unused)".
The “continuous arrangement mode (unused)” is the same as the “continuous arrangement mode (used)”, but the unused portion in the secured continuous area is managed based on the number of divisions and the position information. The recording order of the position information must be recorded in order from the largest empty space. For example, a file can be read by subtracting an unused portion from the continuous area and connecting the used portion from the previously recorded portion.

FIG. 14 shows the relationship between the management information and the data on the disk in the case of the "continuous arrangement mode (use unused)". In the “continuous arrangement mode (used / unused)”, it is assumed that management is performed on both used and unused portions in an area continuously secured by the number of divisions and the position information. It is necessary to record the position information in the order of reading from the disk for each used partition first, and then record the unused partitions in descending order of their size. In managing the used part and the unused part at the same time, it is impossible to distinguish whether the location information manages the used part or the unused part. Therefore, the discrimination is performed using the reserved most significant bit b31 of the start block number of the position information. When the most significant bit b31 is 0, it means that the used part is expressed, and when the most significant bit b31 is 1, it means that the position information of the unused part is managed. .

By using these functions according to the situation and the control program, a continuous area for recording a certain file is secured in advance, and at the same time, the information of the file is stored in the secured continuous area. It is possible to manage how it is actually recorded.

Here, consider a case where video data compressed by, for example, MPEG is recorded on a disk. Even when an MPEG video is considered as a stream, recording is started and stopped, and then additionally recorded, these data are not divided into two files, but are treated as one file when viewed from the file system. Shall be. Since the MPEG data recorded on the disk is data synchronized with time, in order to reproduce video data, it is necessary to read data from the disk within a certain fixed time, decode the data, and display it on a screen or the like. If data cannot be read from the disk within the fixed time, the video on the screen will stop. To prevent such a situation from occurring, a buffer memory for temporarily storing data read from the disk is prepared. By taking advantage of the fact that the speed of reading data from the disk and the speed of data flowing into the buffer memory is faster than the speed of flowing from the buffer memory to the MPEG decoder, there is no problem even if the flow of data from the disk stops to some extent. I have.

As described above, when the MPEG stream data to be read is scattered on the disk, the flow of data into the buffer memory stops for each non-consecutive portion. While the inflow of the data is stopped, the use of the data stored in the buffer memory prevents the output video or the like from stopping. However, if the data is scattered all over the disk, the time during which the flow of data into the buffer memory stops may increase, and the data stored in the buffer memory may be lost. Increasing the amount of buffer memory is also an effective measure to some extent, but this time requires time to store sufficient data in the buffer memory, which degrades the balance when considered as a system. In other words, a certain period of time after the user makes a reproduction request is a time for accumulating data in the buffer memory, and it takes time for video data to actually appear on a screen or the like.

In view of the above, when recording MPEG data on a disc, it is desirable to write the data as continuously as possible. The data to be recorded on the disc is this M
In the case of only PEG2 data, it is easy to record data continuously, but when recording a plurality of types of data such as still images, music data, texts, programs, etc. on one disk, these data are not recorded. There is no guarantee that data can be written continuously because they are mixed on the disk.

Therefore, in order to continuously write the MPEG data on the disk, a continuous area for recording the MPEG data is secured before actually recording the data. This prevents other types of data from being recorded in the continuous area reserved in advance, and
EG data can be continuously arranged on the disk.

Here, the processing steps will be described by taking as an example the case where this MPEG is actually recorded on a disk. FIG. 1 shows a flow of processing when a continuous area securing request is issued. First, when a continuous area reservation request is issued in step 1, a search is made in step 2 as to whether or not there is an area of a size to be continuously reserved using a space bit map. If not, error processing is performed in step 4. When an area that can be continuously secured is found, in step 3, the continuous attribute of the file descriptor for managing the file corresponding to the MPEG stream to be recorded is made valid. This indicates that this file is in a mode for securing a continuous area. Since the continuous attribute is valid, the position information (starting logical block number and block number) of the continuous area to be secured on the disk is recorded in the continuous area position information of the file descriptor. Then, the information of the space bitmap corresponding to the continuously secured area is updated. As a result, no data is actually written on the disk, but the area is used ostensibly, and other files cannot use this area. with this,
The area is secured.

Next, the step of updating the management information when the MPEG stream is actually recorded will be described. In actually recording the MPEG stream in the continuously secured area, the way of updating the file descriptor differs depending on the mode of the continuous attribute. For example, it is assumed that the size of the continuously secured area is an area in which video data for two hours can be recorded for easy understanding. First,
It is assumed that video data for 10 minutes is recorded in this area. On the disc, a 10-minute disc area of a 2-hour area is used. As the management information, when starting a new recording or reading data, it is necessary to manage where in the continuously secured area is used and where is not used.

FIG. 2 shows a processing flow when a data write request occurs. First, when a file creation request is generated in step 10, it is determined in step 11 whether the continuous arrangement mode is set. In this case, since the mode is the continuous arrangement mode, a free area in the area is searched from the number of divisions and the position information in the file descriptor based on the size of the data to be recorded in step 12, and the position to write the data is determined. At this time, if a continuous area corresponding to the size of the data to be recorded cannot be secured, a divided area within the already secured area is secured and used as a write position. If there is no free area for the size of the data to be written in the continuously secured area, step 16
Performs error processing.

In step 14, after data is actually written to this position, in step 15, a file descriptor for managing this file is written to the disk. This file descriptor records the name of the written data, the continuous arrangement attribute, the date and time of creation, and the position information on the disc. The number of divisions and the position information are handled differently depending on the continuous arrangement mode as follows.

When the continuous attribute of the file descriptor is "continuous arrangement mode (use)", the start logical block number of the recorded MPEG stream and the number of logical blocks are recorded in the position information in the file descriptor. The information on the free area in the continuous area is obtained by subtracting the position information of the used part from the continuous area position information in the internal processing of the microcomputer or the like.

When the continuous attribute of the file descriptor is "continuous allocation mode (unused)", the position information in the file descriptor records the free space of the continuously secured area. The position information must be recorded in the order of the free space in the descending order. In this case, in order to specify the position or order in which the MPEG stream is recorded,
It is also possible to manage it separately using a management file for managing the recording state of the MPEG stream.

When the continuous attribute of the file descriptor is “continuous allocation mode (use / unused)”, the position information in the file descriptor includes the starting logical block number of the recorded MPEG stream, the number of the logical blocks, and the continuous securing. The empty area of the set area is recorded. As the recording order of the position information, the used part is recorded first in the order for forming the MPEG stream, and then the position information relating to the empty part division is recorded in descending order. Whether to use the mode in the continuous arrangement mode is to select a mode suitable for control by the control microcomputer.

As described above, by treating the area continuously secured for recording the MPEG stream as one large file ostensibly, it is possible to prevent other types of data from being mixed in the same area. At the same time, it is possible to manage the status of use in the continuously secured area.

When the MPEG stream is sequentially recorded on the disk in the initial state, it is written continuously from the beginning in the continuous area secured in advance. However, if the user wants to delete a part of the previously recorded video from the disk, for example, the deleted part becomes wormy. This open portion is also a target of an area on the disk where new MPEG data can be recorded. Also in this case, the above-described continuous arrangement mode is effective. As already mentioned, MP
Even if a part of the EG stream is deleted, other files cannot use the empty area as long as it is within the continuously secured area. Also, since the management is also performed on the status of the used or unused portion in the secured continuous area, it is possible to easily cope with a new video recording.

Further, editing such as partial deletion is repeated,
For example, when the continuity of the recorded MPEG stream becomes low, the MPEG stream may be rearranged to restore the continuity. Even when performing this relocation, if it is known that only the MPEG stream is recorded in the continuously secured area, the relocation is performed in comparison with the case where other types of files are mixed. It can be done easily.

In the case where MPEG video data is recorded, an area continuously secured in advance becomes insufficient, and there may be a case where the area needs to be expanded. In such a case,
Expansion is possible only when an area that is continuous with the already secured area can be newly secured. Conversely, when the area is reduced, it is effective unless the area to be released is actually used.

This continuous arrangement attribute is not used only for data such as MPEG, but can also be used for management information for performing frequent reading and writing. Of course, reading data from the disk or writing data continuously can be performed faster. From this point of view, in management information in which reading and writing frequently occur, the higher the speed, the better the response of the entire system. Therefore, in order to prevent such management information from being divided and recorded on the disc, the continuous arrangement attribute can be used. For the area of the maximum size of the management information or the size expected in normal use in advance, enable the continuous allocation attribute of the file descriptor,
A continuous area corresponding to the assumed size is set in the continuous area position information. Subsequent management is the same as in the case of MPEG. As a result, even when the amount of management information increases with use, continuous arrangement on the disk is guaranteed, and it is possible to prevent an increase in the time for reading and writing to the disk due to the division of the management information. It becomes possible.

[0058]

As is apparent from the above description, the present invention has the following effects. According to the first aspect of the present invention, when recording one data file, a continuous area of an arbitrary size is secured on a disk medium without actually recording data, and at the same time, the use status in the continuous area is simultaneously determined. Because it is managed, data is not actually written on the disk, but that area is reserved for the defined file, and other files and directories other than this file can not use this area . Therefore,
For example, when reading data from a disk, data reading and updating do not occur in a complicated manner, and the time required for the disk drive head to perform unnecessary seeking can be reduced as much as possible, and the processing speed is also high. Can be read out. Further, as for a file in which a continuous area is secured, the recording position on the disc is limited to the area, so that the worst time for reading and writing data can be estimated, and the access time can be guaranteed. .

According to the second aspect of the present invention, in the continuously secured area, only the portion used as the use status is managed. Therefore, in managing one file, the continuous area is secured in advance. At the same time, it is possible to manage the used portion inside the area.

According to the third aspect of the present invention, in the continuously secured area of the first aspect, only the unused portion is managed as the use status. Therefore, in managing one file, the continuous area is secured in advance. At the same time, it is possible to manage the unused portion inside the area.

According to the fourth aspect of the present invention, in the continuously secured area according to the first aspect, since both the used portion and the unused portion are managed as the use status, one file is managed. In this case, it is possible to secure a continuous area in advance and simultaneously manage both a used part and an unused part in the area.

According to a fifth aspect of the present invention, in the disk medium management method of the first aspect, switching between securing a continuous area for one data file and not securing a continuous area is performed. By switching between securing a continuous area and not securing a continuous area, it is possible to give flexibility to the management method.

According to a sixth aspect of the present invention, in the disk medium management method according to the first aspect, means for calculating a maximum seek time for seeking in the secured continuous area is provided. You can get the maximum seek time when seeking an address, for example,
Control for reading and writing data that requires real-time properties is facilitated.

According to a seventh aspect of the present invention, in the disk medium management method according to the first aspect, when a maximum allowable seek time for seeking in a continuous area to be secured is specified,
By using the means for calculating the area on the disk medium that satisfies the maximum allowable seek time, by giving the maximum seek time when the disk drive seeks the target address, the area that satisfies the maximum allowable seek time can be obtained. For example, control when reading and writing data that requires real-time properties is facilitated.

[Brief description of the drawings]

FIG. 1 is a flowchart showing processing when a continuous securing request is issued.

FIG. 2 is a flowchart illustrating a process when a data write request occurs.

FIG. 3 is a flowchart illustrating a process when a data read request occurs.

FIG. 4 is a diagram showing a basic volume descriptor.

FIG. 5 is a diagram showing a directory descriptor.

FIG. 6 is a diagram showing a file descriptor.

FIG. 7 is a diagram showing details of a continuous arrangement attribute.

FIG. 8 is a diagram showing position information recorded in a file descriptor.

FIG. 9 is a diagram showing an outline of a space bitmap.

FIG. 10 is a diagram showing a state in which one file can be divided and recorded on a disk.

FIG. 11 is a diagram showing a state of a relationship between management information and data on a disk in a normal mode.

FIG. 12 is a diagram showing a state of a relationship between management information and data on a disk in a continuous arrangement mode (use).

FIG. 13 is a diagram showing a state of a relationship between management information and data on a disk in a continuous arrangement mode (unused).

FIG. 14 is a diagram showing a state of a relationship between management information and data on a disk in a continuous arrangement mode (unused).

FIG. 15 is a diagram showing an outline of a relationship between management information of a conventional FAT system and data on a disk.

FIG. 16 is a diagram showing an outline of management information in UDF according to the related art.

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Claims (7)

[Claims] 1. A disk medium management method for managing data recorded on a disk medium in a file format,
When recording one data file, a continuous area of an arbitrary size is secured on the disk medium without actually recording data, and the use state in the continuous area is managed. Disk media management method. 2. The disk medium management method according to claim 1, wherein only a portion used as a use status is managed in the secured continuous area. 3. The disk medium management method according to claim 1, wherein in the secured continuous area, only a part that is not used as a use status is managed. 4. The disk medium management method according to claim 1, wherein in the reserved continuous area, both a used portion and a unused portion are managed as a use status. 5. The disk medium management method according to claim 1, wherein it is possible to switch between securing the continuous area for one data file and not securing the continuous area. 6. The disk medium management method according to claim 1, further comprising means for calculating a maximum seek time for seeking in the secured continuous area. 7. In order to secure the continuous area, when a maximum allowable seek time for seeking in the continuous area to be secured is designated, an area on the disk medium satisfying the maximum allowable seek time is calculated. 2. The disk medium management method according to claim 1, further comprising means.