JPH07160552A - Bit map file access system - Google Patents

Abstract

PURPOSE:To improve processing efficiency of file access control by decreasing probability of generating the competition of access by distributing continuous bits to respective records in a relative file with the record of a bit map file as an exclusive control unit. CONSTITUTION:A bit map file access system 1 is composed of a file access means 5 defining the relative file for performing access with a relative record number in the file as a key as processing object, bit map file 2 of relative file structure for performing exclusive control by the unit of a records, bit sequential number 3 for accessing the bit information of the bit map file 2, bit access deciding means 7 for deciding which bits of which records a relative bit in one record and the bit sequential number 3 desired to be accessed are correspondent to, and area 6 able to be accessed from plural processes while storing the number of records in the bit map file 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system having a file exclusive control function for each record and an access method to a relative organization file using a relative record number in a file as a key, and more particularly to a bitmap file access system. .

[0002]

2. Description of the Related Art Conventionally, as described in Japanese Patent Application No. 63-158641, Japanese Patent Laid-Open No. 63-158641, when bit information stored in a file is accessed, a bit serial number is continuously arranged in the file. , Processing based on bit information was executed.

Therefore, normally logically consecutive bits were contained in a single record.

[0004]

In the above-mentioned conventional technique, when adjacent bit information is accessed from a plurality of processes, for example, in an online transaction processing system, consecutive serial numbers are added to transmitted and received telegrams, and the serial numbers are bit-serialized. In the case of management using a map file, there is a problem that logically consecutive bits are accommodated in a single record, which causes a decrease in processing efficiency due to exclusive control.

[0005]

[Means for Solving the Problems] File access means for processing a relative organization file which has a file exclusive control function for each record and uses the relative record number in the file as a key, and a plurality of records having a relative key A bit map file having a relative organization file structure in which a unit of exclusive control processed by the file access means corresponds to one record, and a bit access for determining which bit of which record corresponds to the bit sequence number to be accessed It comprises a determining means and an area which stores information on the number of records in the bitmap file and which can be accessed by a plurality of processes.

When the file access means bit accesses the serial number X, the bit access determining means uses the number K of records of the bitmap file stored in the area accessible by a plurality of processes as the bit serial number X to be accessed. A step of obtaining a quotient Y and a remainder M when divided, a step of associating a relative key of a record of the bitmap file with the remainder M, and requesting the file access means to read the corresponding record; Of the relative bit in the record of the selected record
There is a step of accessing the Y-th bit information as the bit corresponding to the bit information to be accessed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the flow of processing for accessing bit information according to the present invention, and shows the configuration of a bitmap file access system 1 having a file exclusive control function for each record.

Bitmap file access system 1
Is a file access means 5 for processing a relative organization file that is accessed using the relative record number in the file, and there are K records having a relative key 4 starting from 0, and the file access means 5 is exclusive. Bit map file 2 having a relative organization file structure in which the unit of control corresponds to one record, bit access determining means 7 for determining which relative bit of which record the bit sequence number 3 to be accessed corresponds to, and bitmap file 2 And an area 6 which stores information on the number K of records and is accessible from a plurality of processes.

The number of records in the bitmap file K
Is obtained from the bitmap file 2 via the file access means 5 before accessing the bit information, and stored in the area 6 by the bit access determination means 7. In this way, the number of records K is first obtained and stored in the area 6 at first, and thereafter, the bit information of the bitmap file 2 can be accessed using the value of the area 6 as the number of records.

FIG. 2 is a flowchart of the algorithm of the bit access determining means 7, and the case of accessing the bit serial number X will be described with reference to FIG.

First, the bit access determining means 7 divides the bit serial number X to be accessed by the number K of records of the bitmap file 2 stored in the area 6 accessible by a plurality of processes, and the quotient Y and the remainder M. Is calculated (step 21).

Then, the relative key 4 of the record of the bit map file 2 is made to correspond to the remainder M, and the file access means 5 is requested to read the corresponding record (step 22). Since the Yth bit of the relative bit in the record of the record read here corresponds to the bit information to be accessed, the bitmap file access requesting means 8 is requested to access the information of the Yth bit (step 23).

In FIG. 3, a case where the number of records K is 10 and the bit sequence number to be accessed is 12 will be specifically described as an example.

First, the bit access determining means 7 acquires the number of records from the area 6, and then divides the accessed bit serial number = 12 by the number of records = 10. Here, since the quotient is 1 and the remainder is 2, the file access means 5 reads the record of the relative key = 2 from the bitmap file 2. Further, the first relative bit (the hatched portion in FIG. 3) of the read record is the access target (the first is the 0th bit).

By thus defining the access to the bitmap file, in the case of the access of the bit sequence number = 11, the record having the relative key = 1 different from the record having the bit sequence number = 12 is accessed by the same process. Therefore, even when adjacent bits are accessed from multiple processes, it is possible to avoid the situation where both access the same record and conflict.

In this way, when a logically continuous bit string is distributed and arranged in a record, which is an exclusive control unit, as described with reference to FIG. 2, continuous bits are accessed from a plurality of processes (for example, In the online transaction processing system, it is possible to reduce record access conflicts which occur when a serial number is added to a transmitted / received electronic message and the serial number is managed using a bitmap file.

[0018]

As described above, the present invention is based on a relative organization file in which records of a bitmap file are used as exclusive control units, and the probability of access conflict occurring by dispersing consecutive bits in each record is increased. It is possible to reduce the number and improve the processing efficiency by controlling the file access.

[Brief description of drawings]

FIG. 1 is a block diagram showing a flow of processing for accessing bit information of the present invention.

FIG. 2 is a flowchart of bit access determining means of the present invention.

FIG. 3 is a block diagram showing a specific example of access to bit information of the present invention.

[Explanation of symbols]

 1 Bitmap file access system 2 Bitmap file 3 Bit serial number 4 Relative key 5 File access means 6 Record number storage area 7 Bit access decision means 8 Bitmap file access request means 21, 22, 23 steps

Claims (2)

[Claims] 1. A file access means for processing a relative organization file which has a file exclusive control function for each record and is accessed by using a relative record number in the file as a key, and a plurality of records having a relative key are present. A bit map file having a relative organization file structure in which the unit of exclusive control processed by the file access means corresponds to one record, and a bit access determination means for determining which relative bit of which record corresponds to the bit sequence number to be accessed. A bitmap file access system including an area that stores information on the number of records of the bitmap file and that can be accessed by a plurality of processes. 2. When the file access means accesses the bit sequence number X, the bit access determination means records a bit map file in which the bit sequence number X to be accessed is stored in an area accessible from a plurality of processes. A step of obtaining a quotient Y and a remainder M when divided by a number K; a step of requesting the file access means to read a corresponding record by associating a relative key of a record of the bitmap file with the remainder M; The bit map file according to claim 1, further comprising a step of accessing the information of the Y-th bit, assuming that the Y-th bit of the relative bit in the record of the record read corresponds to the bit information of the access target. Access system.