JPS63158641A - Idle file control system - Google Patents

Abstract

PURPOSE:To shorten a program processing time, and to make a control efficient by obtaining the idle record of a data file with the aid of a bit information stored in a bit map file. CONSTITUTION:When a bit 24 is 1, a corresponding record 27 is in the course of being used, and when the bit 24' is '0', the corresponding record 27' is the idle record. When a program to use the data file 25 obtains the idle record from the file 25, it searches the bit information 23 of the bit map file 21, and when the 0-bit 24' is obtained, the record 27, which has the same record correspondence number as the said bit correspondence number, is obtained as the idle record. Afterwards, when the obtained record is used, the bit 24' concerned is made to be '1'. Besides, when the record 27, which is used by the program to use the file 25, is made to be the idle record, the bit 24, the record 27 corresponds to, is made to '0'.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a file free space management method, particularly to a file free space management method in a computer system equipped with a one-disk file device.

[Common technology]

Generally, the basic operating system of a general-purpose computer/minicomputer manages three types of file management methods: sequential organization, relative organization, and indexed sequential organization. It is well known that of these, relative organization files that can be accessed by record number have the highest access efficiency.

[Conventional technology]

In conventional file space management methods, information on whether a record is in use or unused is stored in the record, and when a program obtains a free record, it reads the records in the file one after another and makes a determination.

[Problem that the invention seeks to solve]

The above-mentioned conventional file free management method has the disadvantage that the program processing time becomes long and efficiency deteriorates because records of a file are sequentially read and determined in order to obtain free files.

[Means for solving problems]

The file free space management method of the present invention includes the steps of searching for the θ bit of a bitmap file that stores bit information, and searching for a record of a relative format data file at the same record relative position as the above O bit bit position. a step of setting the O bit of the bitmap file to 1; and a step of setting the use record of the data file as a free record;
The method includes the step of setting one bit of the bitmap file at the same bit relative position as the record relative position of the used record to 0.

〔Example〕

Next, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a flowchart showing one embodiment of the present invention, and FIG.
The figure is a flowchart showing an embodiment of converting usage records of the present invention, and FIG. 3 is a file configuration diagram of the embodiment.

The file free space management method of the present invention includes step 11 of searching for 21 O bits 24' of a bitmap file storing bit information 23, and a relative organization format at the same record relative position as the bit relative position of bit 24'. A step 12 in which the record 27' of the data file 25 is set as a used record, a step 13 in which the O bit 24' of 21 in the bitmap file is set to 1, and a step 14 in which the used record 27 in the data file 25 is set as an empty record. and 2 of the bitmap file at the same bit relative position as the record relative position of the usage record 27 above.
and step 15 of setting one bit 24 of 1 to O.

Next, the present invention will be explained in detail.

Each bit 23 of the bit information 23 stored in 21 of the bitmap file indicates the status of the record 27 having the record relative number 26 of the data file 25, which corresponds one-to-one with the bit relative number 22. . When bit 24 is 1, the corresponding record 27 is in use; when bit 24' is O, the corresponding record 2 is in use.
7' is an empty record. When a program that uses the data file 25 obtains a free record from the data file 25, it searches for the bit information 23 of 21 in the bitmap file, and when the O pit 24' is obtained, the record relative number is the same as that bit relative number. Record 27 with
′ is obtained as an empty record.

Thereafter, when using the obtained record, the corresponding bit information 23 bit 24' is set to 1.

Further, when the program using the data file 25 makes the record 27 of the data file 25 that it was using an empty record, the bit 24 of the corresponding bit information 23 of the record 27 is set to 0.

〔Effect of the invention〕

The file free space management method of the present invention obtains free records in a data file using bit information stored in a bitmap file, so the program processing time is short.
This has the effect of improving efficiency.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing one embodiment of the present invention, and FIG.
The figure is a flowchart showing an embodiment of converting usage records of the present invention, and FIG. 3 is a file configuration diagram of the embodiment. 11... step of searching for the O bit of the bitmap file, 12... step of setting the record of the data file at the same record relative position as the bit relative position of the bit as the record to be used, 13・・・・・・
... Step of setting the O bit of the bitmap file to 1, 14 ... Step of making the used record of the data file a free record, 15 ... ... The same bit as the record relative position of the used record Step 21 of setting 1 bit of the bitmap file at a relative position to 0...22 of the bitmap file
...Number indicating bit relative number, 23...
・Bit information, 24.24'...Bit, 25
・・・・・・Relative organization format data file, 26...
...Number indicating relative record number, 27.27'.
... Record death. 7″... Agent Patent Attorney Shin Uchihara, 3 Soge 1 million 2 times

Claims (1)

[Claims] A first step of searching for a 0 bit in a bitmap file that stores bit information, and a second step of searching for a 0 bit in a bitmap file that stores bit information, and a second step in which a record of a data file in a relative organization format at the same record relative position as the bit relative position of the 0 bit is used as a record. a third step of setting the 0 bit of the bitmap file to 1; and a fourth step of setting the used record of the data file to a free record, the bit relative position being the same as the record relative position of the used record. and a fifth step of setting one bit of the bitmap file to 0.