JPH03219340A - Sequential organization file accessing system utilizing control file - Google Patents

Abstract

PURPOSE:To effectively utilize a file space by erasing record control information from a formed control file, updating the information or copying the information in another file. CONSTITUTION:A control file forming means 203 successively reads out records from a sequential organization file 301, decides whether each record is effective one or not based upon an instruction from a user's program 101 and registers record control information in a control file 302 and a control file referencing means 204 sequentially extracts only the effective records in a sequential organization file 301. A control file initializing preparation means 202 decides a requirement from a user program, transfers the control to the means 203 in the case of a formation requirement or transfers the control to the means 204 in the case of a transfer requirement and a control file service means 205 erases or updates the record control information or copies the information to another file. Consequently, processing can be executed in a saved file space.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sequential file access method, and particularly to a sequential file access method using a control file.

[Conventional technology]

Conventionally, when using only a portion of records in one sequential file as one file, or when using a sequential file excluding a portion of records as one file, III&! Extract only the records you need from a configuration file and copy them to another file,
This was done by either re-creating the sequential file and updating the file to make it compatible with the user program, or by checking the contents of the record on the user program side.

[Problem to be solved by the invention]

In the conventional technology described above, data in a sequential file is considered to be a collection of records, and when classifying the data according to certain conditions, if there are records that belong to two or more conditions, the same record is divided into multiple files. Therefore, there is a drawback that the total size of the multiple divided files may be larger than the size of one file containing the entire record.

In view of the above-mentioned points, an object of the present invention is to solve the problem when a sequential file is divided into a plurality of files as long as there is one real file storing all records and the number of classified control files consisting of record control information. An object of the present invention is to provide a sequential file access method using a control file that enables similar processing in a saved file space.

[Means to solve the problem]

The sequential file access method using the control file of the present invention sequentially reads records from a sequential file configured on a large-capacity storage medium and determines whether or not each record is valid based on instructions from the user program. A control file creation means that registers record control information for records in a control file, and sequentially extracts only valid records in the sequential file based on the record control information in the control file created by the control file creation means. A control file reference means that enables the user program to determine whether a request from a user program is to create or reference a control file, and if it is a creation request, control is passed to the control file creation means and if it is a reference request, control is passed to the control file creation means. It has a control file initialization preparation means for passing control to a reference means, and a control file service means that enables processing such as erasing, updating, or copying record control information of a created control file to another file.

[Effect]

In the sequential file access method using the control file of the present invention, the control file creation means sequentially reads records from a sequential file configured on a mass storage medium and determines whether the records are valid or not based on instructions from the user program. The record control information for each record is registered in the control file, and the control file reference means selects only valid records in the sequential file based on the record control information in the control file created by the control file creation means. The control file initialization preparation means determines whether the request from the user program is to create or reference a control file, and if it is a creation request, it passes control to the control file creation means and if it is a reference request. Control is passed to the control file reference means to enable the control file service means to perform processing such as erasing, updating, or copying the record control information of the created control file to another file.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a sequential file access method using a control file according to an embodiment of the present invention. The sequential file access method using a control file of this embodiment includes a user program 101, a service program 102, a control file initialization preparation means 202. Control file creation means 203. Control file reference means 204 and control file service means 205
data processing bag N201 containing
and a control file 302. In addition, in FIG. 1, the reference numeral 11 indicates the user program 101.
12 is a control file update request signal from the service program 102, 13, 14 and 15 are control file initialization preparation means 202, control file creation means 203 and control file creation means 203 in sequential file input/output processing. A processing request signal 16 is sent to the control file reference means 204 from the sequential file 3 from the data processing device 201.
01 and a physical input/output request signal to the control file 302, respectively.

FIG. 2 shows the contents of the control file 302, which is composed of a file label area and multiple record control information areas.

The file label area contains the control file 302.
Information indicating that the corresponding sequential file 301
Information etc. to ensure consistency with the data is stored. The record control information is composed of a record number, control information, and the record size of each record of the corresponding tit file 301, and there are 111 records equal to the number of records in the body of the tit file 301. The control information mainly includes skip (SKIP) information and end (IEND) information, and records existing in the sequential file 301 can be logically deleted by the control file creation means 2o3 and the control file service means 205, Performs control such as setting the logical end of file (EOF).

Referring to FIG. 3, the process when creating the control file 302 in the user program 101 is performed in step 2 of executing the sequential file oven (OPEN) command.
1, sequential file read (READ) command execution step 22, and sequential file EOF determination step 2
3, a valid record determination step 24, a 5KIP command execution step 25, an end determination step 26, and an E
ND command execution step 27, ll[wA formation rough aisle close CL OS E) command execution step 2
It consists of 8.

Referring to Figure 4, control file initialization! 1
! The processing in the preparation means 202 includes a sequential file orphan processing step 31, a control file presence/absence determination step 32, a control file initialization determination step 33, a control file initialization processing step 34, and a control file reference preparation processing step 3.
It consists of 5.

Referring to FIG. 5, the processing of the control file creation means 203 during the READEND command execution step 22) in the user program 101 includes a sequential file code reading step 41 and a control file record control B information writing step 42. Consisting of

Referring to FIG. 6, the processing of the control file creation means 203 when executing the 5KIP command (step 25) in the user program 101 consists of a step 51 of writing 5KIP information into record control information.

Referring to FIG. 7, the process of the control file creation means 203 when executing the END command (step 27) in the user program 101 is as follows:
It consists of an ND information writing step 61 and a remaining record number record control information writing step 62.

Referring to FIG. 8, control file reference means 2
04 includes a sequential file EOF determination step 71, a record control information 5KIP information determination step 72, a pointer update step 73, a sequential file code reading step 74, and a record control information EN
It consists of a D information determination step 75 and a next READ command execution order file EOF setting step 76.

Next, the operation of the M file access method using the control file of this embodiment configured as described above will be explained.

The basic processing flow of the sequential file access method using the control file of this embodiment is that the user program 101 sequentially accesses the sequential file 301 via the data processing device 201. If the file 302 exists in the process, the control file reference means 2o4, the control file creation means 203, or the control file service means 205 are activated depending on the processing content, and the sequential file 301 is controlled while controlling the control file 302. to access. Further, the control file service means 205 is directly activated by the service program 102 to update or copy the control file 302.

ill First, the process of creating the control file 302 will be explained in detail.

0P of the sequential file 301 in the user program 101
When the EN command is executed (step 21), the control file initialization preparation means 202 performs the same opening process as before for the sequential file 301 (step 31), and then determines whether the control file 302 exists or not. 32) If the control file 302 does not exist, the process ends. If there is a control file 302, the control file initialization preparation means 202 must determine whether the control file initialization instruction from the user program 101 is output mode (to be initialized) or input mode (to be initialized). Step 33), since it is necessary to initialize the control file 302 when creating it, initialization processing including oven processing of the control file 302 is performed (step 34).

Next, the user program 101 starts the sequential organization file 301
When the READEND command is executed (step 22), the control file is created - [203 reads the code from the sequential file 301 (step 41), record control information is created from the record number and record size of the read record, and the control file 3 is created.
02 (step 42).

Next, the user program 101 writes the sequential file 3
Step 23) Determine whether 01 is EOF or not.
, EOF, control is transferred to step 28, EOF
If not, it is determined based on the contents of the read record whether it is a valid record or not (step 24).

If the read record is not a valid record, the user program 101 executes the 5KIP command (step 25); if the read record is a valid record, the user program 101 does not execute the 5KIP command.

When the user program 101 executes the 5KIP command, the control file creation means 203 writes 5KIP information into the control information of the record control information written to the control file 302 in step 42, and virtually creates the corresponding record of the sequential file 301. (Step 51).

Next, the user program 101 determines whether or not to terminate the process (step 26). If not, return control to the steering knob 22, and if to terminate, press EN.
Execute the D command (step 27).

If the user program 101 executes the END command before reading all records of the sequential file 301, the control file creation means 203 adds END information to the control information of the record control information written to the control file 302 in step 22. After setting the virtual EOF of the sequential file 301 by writing (step 61), the remaining records of the sequential file 301 are internally read sequentially and record control information for that number is written in the control file 302. (
Step 62).

Finally, the user program 101 executes the sequential organization file 3
Execute the CLO3E command of 01 (step 28)
.

When the CLO3E command is executed by the user program 101, the user program creation means 203 performs the closing process of the sequential file 301 and also closes the control file 302.

The control file 302 is created in this way, but by using the control file service means 205 from the service program 102, the control file 302 that has already been created can be used for 5KIP9i information and E-mail.
ND! You can cancel the information, add a new one, or copy the control file 302 to create another control file 302.

+2) &, the process of setting the control file 302 to 11 and accessing the sequential file 301 as a virtual file will be described.

0P of the sequential file 301 in the user program 101
When the EN command is executed, the control file initialization preparation means 202 creates a sequential file 3 similar to the conventional one.
After performing the oven processing of 01 (step 31), the presence or absence of the control file 302 is determined in step 32.
), if there is no control file 302, the process ends as is; if there is a control file 302, the control file initialization instruction from the user program 101 is disabled. Step 33
The control file 302 is not initialized when referenced, so after confirming that the specified control file 302 corresponds to the sequential file 301, reference preparation processing including oven processing of the control file 302 is performed (step 35). ).

Next, the user program 101 uses the vi organization file 30
When the READ command 1 is executed, the control file reference means 204 determines that the sequential file 301 is EOF.
Step 7 1) , EOF
If it is IEO, the process ends, and if it is not IEO, the control file 3 corresponding to the requested record is created.
Check whether the control information is not SKIP information by referring to the record control information in 02 (step 7
2).

If SKIP information is set in the control information, the control file reference means 204 advances the current calendar and the pointer of the control file 302 by the number of codes in order to virtually delete the record without reading the record. (Step 73), and checks whether the record control information of the next record is SKIP information (Step 72). If the control information in the record control information is not SKIP information, the control file reference means 204 reads the record from the sequential file 301 and transfers the record to the user program 101 (step knob 74), and the control information is END information. (Step 7)
5), Control information is END! If it is not information, the process is terminated, and if it is END information, a virtual EOF is set so that the sequential file 301 will be in the EOF state when the next READ command from the user program 101 is executed. (Step 76), the process ends.

By performing the above processing, if the sequential organization file 301 as shown in FIG. 9(a) is manually created by converting the control file 302 as shown in FIG. 9(b) into 411,
Data records 2 and 5 are skipped, and EOF occurs after data record 6 is read.
) records will be read in the following order.

In this way, in this embodiment, the sequential file 301 can be used as a virtual separate file based on the record control type information of the external control file 302 without modifying the main body of the sequential file 301. If a plurality of types of control files 302 are prepared, it becomes possible to use the same number of files, thereby saving file space on the storage medium.

〔Effect of the invention〕

As explained above, the present invention provides control file initialization preparation means. By providing a control file creation means, a control file reference means, and a control file service means, a part of a sequential file on a mass storage medium can be referred to as one file by record control information of an external control file. You can refer to the file excluding that record as one file or use it virtually as a separate file, and by preparing multiple control/roll files, you can store one sequential file This has the effect of making it possible to use it evenly and making effective use of the file space on the storage medium.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a sequential file access method using a control file according to an embodiment of the present invention, FIG. 2 is a diagram showing the contents of the control file in FIG. 1, and FIG. A flowchart showing the process when creating a control file in the user program in Figure 1, and Figure 4 is a flowchart showing the process when creating a control file in the user program.
A flowchart showing the processing of the control file initialization preparation means in the figure.
A flowchart showing the processing of the control file creation means when executing a command, Figure 6 shows the 5KIP in the user program in Figure 3.
A flowchart showing the processing of the control file creation means when executing a command, FIG. 7 shows the E N in the user program in FIG.
D': 177) - A diagram showing the processing of the control file creation means during execution, Figure 8 is a flowchart showing the processing of the control file reference means in Figure 1, and Figures 9 (a) to (c) are the main FIG. 7 is a diagram illustrating an example of reading a sequential file using a control file according to the method of the embodiment. In the figure, 11... Sequential file access request signal, 12... Control file update request signal, 13.14.15.
Processing request signal, 16. Physical input/output request signal, 101. User program, 102. Service program, 20. Data processing device, 202. Control file initialization preparation means, 203.
Control file creation means, 204 Control file creation means, 205 Control file service means, 301 Sequential file, 302 Control file.

Claims (1)

[Claims] Records are sequentially read from a sequential file configured on a large-capacity storage medium, and it is determined whether or not the record is valid based on instructions from the user program, and record control information for each record is stored in a control file. control file creation means for registering; and control file reference means that makes it possible to sequentially retrieve only valid records in the sequential file based on record control information in the control file created by the control file creation means. and determining whether the request from the user program is to create or reference a control file, and if it is a creation request, control is passed to the control file creation means, and if it is a reference request, control is passed to the control file reference means. and a control file service means that enables processes such as erasing, updating, or copying record control information of a created control file to another file. Sequential file access method.