JPH0667947A - File data management system - Google Patents

Abstract

PURPOSE:To provide a file data management system which manages a file in the unit of bytes by individual user programs and simplifies an operation on a user-side. CONSTITUTION:In file data management system managing the file 2 by an operating system 1 in a sector unit, a file management information table 5 storing the number of write final sector effective bytes in a write sector 4i into which data is written as file management information into a byte area 15 is provided, and a control means 12 which writes the number of the write final sector effective bytes into the byte area 15 at the time of writing data into the file 2 and reads the number of the write final sector effective bytes in the byte area 15 at the time of reading data from the file 2 based on a system call for writing or reading the number of the write final sector effective bytes which a user issues is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file data management system in which a file is managed by an operating system in units of sectors composed of blocks of a plurality of bytes.

[0002]

2. Description of the Related Art In file management of an operating system, there is a method of managing (reading / writing) files in units of sectors (blocks of a plurality of bytes). FIG. 6 shows an example of this sector unit file management system. As shown in FIG. 6, the file 20 is managed by an operating system (hereinafter abbreviated as OS).

The file 20 has a plurality of sectors 4 each of which is composed of a block of a plurality of bytes as a substance of the file.
a to 4n are provided. Further, the file management information table 30 of the file 20 stores the total number of sectors of the file as management information of the file name and file size.

Since a block of a plurality of bytes is written or read in each of the sectors 4a to 4n, there are advantages that the management is simple and the processing speed is generally high.

[0005]

However, as shown in FIG. 7, when the data 22a is written in the sector 4a, the data 22a is further written in the middle of the sector 4b, and the data write-once process is performed from the continuation of the data 22a. As shown in 8, write-once write data 22b is written from the beginning of sector 4c. Therefore, a gap 23 (empty data) of file data is generated in the sector 4b.

Therefore, conventionally, the user side manages the position to be written next in byte units, and sends the management information to the file 20 to point to the position a of the sector 4b as shown in FIG. Then, the write-once data 22b is written from the position a so as to eliminate the above-mentioned gap 23 of the sector 2b.

However, when the user side manages the data in byte units, it is necessary for the user side to read the data for additional writing from the medium (file) and reflect it on the medium. Was difficult to operate.

A file 20 is stored for each user program.
Is provided, and the file 20 is multi-opened and file management is performed in byte units for each user program, so management is troublesome.

The present invention has been made in view of the above circumstances. An object of the present invention is to perform file management in byte units for each user program and to simplify file operation by the user. To provide a management method.

[0010]

In order to solve the above problems and achieve the object, the present invention has the following constitution. FIG. 1 shows the principle of the present invention. The present invention will be described with reference to FIG.

In the file data management system in which the operating system 1 manages the file 2 in units of sectors each consisting of a block of a plurality of bytes, file management information is stored in the file for each file 2, and all sectors 4a to 4n are stored. There is provided a file management information table 5 for storing in the byte area 15 the number of effective bytes in the last write sector in the last write sector 4i in which the data of the above is written.

There is provided a control means 12 for writing or reading the number of valid bytes of the last write sector for writing to the byte area 15 of the file management information table 5, and the control means 12 has the valid byte of the last write sector issued by the user. Based on a system call for writing or reading a number, write the last sector effective byte number to the byte area 15 when writing data to the file 2 and write the last byte area 15 when reading data from the file 2. It is configured to read the number of valid bytes in the sector.

The file 2 is, for example, a magnetic disk, a magnetic tape, an optical disk, a semiconductor file, or the like. As the operating system 1, for example, FM
There are S, OS / 360, OS / 370, CP / M, MS-DOS for microcomputers developed by Microsoft Corporation in the United States, and the like.

The system call issued by the user may be input from an input means such as a keyboard or a mouse. The file management information table 5 stores, for example, a file name, the number of sectors, the number of valid bytes in the last write sector, and the like.

The block of a plurality of bytes is read and written by one input / output operation and is composed of one or more records.
In this record format, all records in the file have the same length, a fixed-length record consisting of one block of one record, an unblocked record, and one block of multiple records, and a variable length in which each record has a variable length. There is an indefinite length record composed of one record and one block.

More preferably, the following is desirable. That is, the control means 12 writes data to a file, writes the write last sector effective byte number in the byte area, and executes a system call for writing or reading the write last sector effective byte number issued by the user. Obtain the number of sectors in the file and the number of valid bytes for the last write sector from the byte area, seek to the last sector for writing based on the number of sectors, read the data, and then point the number of valid bytes for the last write sector from the beginning of the read data. Is moved to write additional data.

Further, the operating system 1
Is provided with a data management section 11 for managing the file 2 and a task management section for managing tasks as the control means 12.

The data management unit 11 writes or reads the management information of the file management information table 5 of the file 2 to or from the main storage device 7, and the task management unit, based on the system call. 7 is configured to write or read the number of valid bytes of the last write sector.

The task is a unit to which a CPU (central processing unit) is allocated to realize multi-programming, and the task management section performs task generation / deletion, task synchronization, and mutual communication.

From the viewpoint of requesting a CPU, a task has three states: an executable state, an execution state, and a standby state. The ready state is a state in which the CPU can be used, the run state is a state in which the CPU is in use, and the standby state is a state in which the CPU cannot be used while waiting for the end of input / output operation. is there.

[0021]

According to the present invention, the file management information table 5 for storing in the byte area 15 the number of valid bytes of the last write sector in the last write sector 4i in which data of all the sectors 4a to 4n has been written, is provided. When the control means 12 writes the data to the file 2 based on the system call issued by the user, it writes the byte count of the last sector effective byte in the byte area 15, and when the data is read from the file 2, the byte area 15 is written. By reading the last sector effective byte number, it is possible to obtain the position within the sector at which data should be written next.

Therefore, even when the system manages files in sector units, the user can access the files in byte units, so that the operation on the user side is simplified, and data writing or reading is performed at the same time. Since the last sector effective byte number is set, the processing becomes quick.

Further, the control means 12 writes the data to the file, writes the number of valid bytes of the last sector to be written into the byte area, and the system call issued by the user causes the number of sectors of the file and the last sector of the file to be valid from the byte area. The number of bytes is obtained, the data is read by seeking to the write last sector based on the number of sectors, and the write-once data is written by moving the point from the beginning of the read data by the write last sector effective byte number. Thus, there is no gap in the final write sector.

[0024]

EXAMPLES Specific examples of the present invention will be described below. <Embodiment 1> FIG. 2 is a configuration block diagram of an embodiment 1 of an apparatus for realizing a file data management system according to the present invention. The device consists of a user side and an operating system side, and as will be described later in detail to the user side,
A system call issuing unit 7 is provided by which a user issues a system call for writing or reading the effective byte number of the last write sector.

The operating system side is constructed as follows. The operating system 1 systematically integrates various programs in order to improve the productivity of data processing, and includes a control program and a processing program. The control program has a data management function, a task management function, and the like, and the processing program includes a user program and the like.

Therefore, the operating system 1
A data management unit 11 that manages the file 2 and a task management unit 12a that manages tasks as control means are provided.

The data management unit 11 writes or reads the management information of the file management information table 5 of the file 2 into or from the main storage device 7. That is, a part of the file management information on the file 2 medium is read onto the main storage device 7 when the file 2 is opened in the write mode and written on the medium when the file 2 is closed for speeding up. It is supposed to be.

The task management section 12a is for performing task generation, task deletion, task synchronization, and mutual communication, and the main storage device 7 is based on a system call from the user.
Write or read the last sector valid byte number.

The task is a unit for allocating a CPU (central processing unit) to realize multi-programming. The file 2 is internally provided with a plurality of sectors 4a to 4n composed of blocks of a plurality of bytes, and data 22a, 22b, ... Corresponding to these sectors, respectively.
・ Is stored. The block of a plurality of bytes is read and written by one input / output operation and is composed of one or more records.

A file management information table 5 storing a file name and the number of file sectors as file management information is provided on the medium of the file 2, and this file management information table 5 further includes all the sectors 4a to 4n. The number of valid bytes in the last write sector in the last write sector 4i in which the data is written is stored in the byte area 15.

The task management section 12a writes or reads the number of valid bytes of the last write sector into the byte area 15 of the file management information table 5, and writes the data to the file 2 to write the last number of valid byte of the write sector. Bi is written in the byte area 15, the sector number i of the file 2 and the write last sector effective byte number Bi are obtained from the byte area 15 by the system call issued by the user, and the write last sector 4i is obtained based on the sector number i.
The data is read by seeking to, and the write-once data is written by moving the point from the beginning of the read data by the write last sector effective byte number Bi.

FIG. 3 is a flowchart showing the processing of the task management unit. A file data management system in the embodiment will be described with reference to the drawings. First, in task 1,
The data 22a to 22n are written to the file 2 in units of sectors 4a to 4n, and the write effective byte count Bi in the final write sector 4i of data is set in the byte count area 15 of the file management information table 5.

After that, when additional writing of data is performed, in task 2, a system call is issued on the user side to obtain the number of sectors of the file 2 and the number of write valid bytes Bi in the last write sector 4i. Issued in part 8.

After this, based on the number of sectors i of the file 2, seek to the write last sector 4i and write last sector 4i
Read the data of i. Then, when the pointer is moved from the beginning of the read data by the write end sector effective byte number Bi, the write start position a is reached. After that, write-once data is written. Furthermore, the data reflecting the write-once data is written on the medium.

As described above, according to the first embodiment, all sectors 4
The file management information table 5 for storing the effective number of write last sector bytes in the write last sector 4i in which the data of a to 4n is written is provided in the byte area 15, and the task management is performed based on the system call from the user. Part 1
Since the bytes are managed by 2a, it is possible to obtain the position a in the sector where the data writing should start next, and by writing the write-once write data from the position a, the gap 23 as in the conventional case does not occur.

Therefore, even when the operating system 1 manages files in sector units, the user can access files in byte units. In this way, the method of centrally managing the last sector effective byte number on the operating system side is such that a plurality of files 2 are multi-opened by a multi-program, as compared with a method in which the user side holds data for additional writing. If the file management information is present, inconsistency hardly occurs in the file management information.

Further, since it is unnecessary for the user to read the data for additional writing from the file medium and to reflect the data on the medium, the operation on the user side is simplified. Further, since the user can freely set information in the area 15 of the file management information table 5, it can be used for purposes other than the above.

<Second Embodiment> Next, a second embodiment of the present invention will be described. FIG. 4 is a configuration block diagram of the second embodiment. The second embodiment is different from the first embodiment in that the task management unit 12a is replaced by
The task management unit 12b is provided.

The task management unit 12b writes the write last sector effective byte number to the byte area 15 when writing the data to the file 2 based on the system call issued by the user, and the byte area when reading the data from the file 2. The number of valid bytes in the last write sector of 15 is read out.

The rest of the configuration is the same as that of the first embodiment, and the same parts will be described with the same reference numerals. Figure 5
Is a flowchart showing the processing of the task management unit 12b. The process of the second embodiment will be described with reference to the drawings.

In task 3, the file 2 is generated based on the system call issued from the system call issuing unit 8.
At the same time when writing the data to, the last sector effective byte number is written in the main storage device 7 to write it in the byte number area 15 of the file management information table 5.

Then, in the task 4, when the write last sector of the file 2 is read during the process of reading the data of the file 2, the last sector of the file 2 is read by the return value of the system call for reading the data. It can be seen that the number of effective bytes Bi is set.

As described above, according to the second embodiment, all sectors 4
The file management information table 5 for storing the effective byte count of the last write sector in the last write sector 4i in which the data of a to 4n is written is provided in the byte area 15, and the task management unit 12a issues the file issued by the user. When writing data to the file 2 based on the system call, the write last sector effective byte number is written to the byte area 15, and when reading data from the file 2, the write last sector effective byte number of the byte area 15 is read.

Therefore, it is possible to obtain the position in the sector where the data writing should be started next, and by writing the write-once write data from that position, the gap 23 is not generated.
As a result, the same effect as that of the first embodiment is achieved, and since the number of valid bytes of the last write sector is set at the same time when the data is written or read, the processing becomes faster than that of the first embodiment.

Although only one file management is shown in the first and second embodiments, the present invention can be applied to a plurality of file managements.

[0046]

According to the present invention, the file management information table is provided with a byte area for storing the number of effective bytes in the last write sector, and when the control means writes data in the file based on the system call issued by the user. By writing the valid last sector write byte count to the byte area and reading the write last sector valid byte count of the byte area when reading the data from the file, it is possible to obtain the position within the sector where the next data write should start. .

Therefore, even when the system manages the file in sector units, the user can access the file in byte units, and when the files are multi-opened, the file management information is less likely to be inconsistent. Further, it is unnecessary for the user side to read the data for additional writing from the medium and to reflect the data on the medium.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration block diagram of a first embodiment of the present invention.

FIG. 3 is a flowchart illustrating processing of a task management unit according to the first exemplary embodiment.

FIG. 4 is a configuration block diagram of a second embodiment.

FIG. 5 is a flowchart showing processing of a task management unit according to the second embodiment.

FIG. 6 is a diagram showing an example of a conventional file management system in sector units.

FIG. 7 is a diagram for explaining writing of data to a sector according to a conventional method.

FIG. 8 is a diagram for explaining writing of the write-once write data from the sector head according to the conventional method.

FIG. 9 is a diagram for explaining writing of write-once write data to a sector by byte management on the user side according to a conventional method.

[Explanation of symbols]

 1-Operating system 2--Files 4a-4n-Sectors 5--File management information table 7-Main memory 8-System call issuing unit 11-Data management unit 12a, 12b-Task management unit 15 ..Byte area 22a, 22b..Data 23..Gap Bi ... Number of effective bytes in last sector of writing a ... Additional data writing start position

Claims (3)

[Claims] 1. A file data management method in which a file (2) is managed by a sector unit consisting of a block of a plurality of bytes by an operating system (1), and file management information is stored in each file (2). And a file management information table (5) for storing, in the byte area (15), the number of valid bytes of the last write sector in the last write sector (4i) in which data of all the sectors (4a to 4n) is written. , Byte area (15) of file management information table (5)
And a control unit (12) for writing or reading the number of valid bytes of the last write sector to write to or reading the number of valid bytes of the last write sector issued by the user. Based on the system call, write the byte area (15) when writing data to the file (2), write the last sector effective byte number, and write the byte area (15) when reading data from the file (2). A file data management method characterized by reading the number of valid bytes in the last sector. 2. The control means (12) writes data to a file, writes a write last sector effective byte number in a byte area, and writes the sector number and write of the file from the byte area by the system call issued by the user. Get the number of valid bytes in the last sector, seek to the last sector to write based on the number of sectors, read the data, and move the point from the beginning of the read data by the number of valid bytes in the last write sector to write additional data. The file data management system according to claim 1, wherein 3. The operating system (1)
Is a data management unit (11) for managing the file (2)
And a task management unit for managing tasks as the control unit (12), wherein the data management unit (11) stores the management information of the file management information table (5) of the file (2) in the main storage device. (7) performs writing or reading, and the task management unit writes or reads the valid last sector write byte number in the main memory (7) based on the system call. Claim 1
Alternatively, the file data management method according to claim 2.