JPH0421041A - Dynamic converting system for file format - Google Patents

Abstract

PURPOSE:To execute the access at a high speed with respect to data of a variable length record file by converting dynamically a file format of the variable length record file and a file format of a fixed length record file. CONSTITUTION:A file allocating means 102 calls a file format converting means 201, based on an allocation request of a file, converts a variable length record file stored in a first data store means 301 to a file format of a fixed length record file and stores it in a second data store means 401, and executes an allocation of the fixed length record file. Subsequently, data of the fixed length record file stored in a second data store means 401 is read and written, the fixed length record file is converted to a file format of the variable length record file and stored in a first data store means 301, and the fixed length record file is released. In such a way, data of the variable length record file can be accessed at a high speed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a file access method, and in particular to a file for rapidly accessing data in a file storing variable-length records (hereinafter referred to as a variable-length record file). Concerning dynamic format conversion methods.

[Conventional technology]

Conventionally, this type of file access method consists of a file access means, a file allocation means, and a file allocation release means.If the file storing data is a variable-length record file, , the data access speed was lower than when accessing data in a file that stores fixed-length records (hereinafter referred to as a fixed-length record file). For this reason, when it is necessary to access data in a variable-length record file at high speed, a fixed-length record file with the same contents as the variable-length record file is prepared to access the data.

[Problem to be solved by the invention]

In the conventional file access method described above, when it is necessary to access data in a variable-length record file at high speed, it is necessary to prepare a fixed-length record file with the same contents as the variable-length record file and access the data. Therefore, before processing the file data, convert the variable-length record file to the fixed-length record file format, and after completing the file data processing, convert the fixed-length record file to the variable-length record file format. In addition to complicating file data processing, there is also the disadvantage that it is necessary to constantly manage whether or not the file being accessed is a fixed-length record file. When accessing and processing data, there is a drawback that the file format often does not match the data processing method, resulting in a decrease in processing efficiency.

In view of the above-mentioned points, an object of the present invention is to dynamically convert the file format of a variable-length record file and the file format of a fixed-length record file so that data in the variable-length record file can be accessed at high speed. The objective is to provide a dynamic conversion method for file formats.

[Means to solve the problem]

The file format dynamic conversion method of the present invention uses variable length records in the file access method.

A first data storage means for storing a variable length record file comprising a record length storage section for recording the record length of each variable length record and a file format recording section for recording that a variable length record is stored; fixed length records; , a second data storage means for storing a fixed-length record file comprising a file length recording section for recording the sum of record lengths of fixed-length records and a file format recording section for recording that fixed-length records are stored; The variable length record file stored in the first data storage means is converted into a file format of a fixed length record file, and the second
File format converting means for storing in the data storage means or converting a fixed length record file stored in the second data storage means into a file format of a variable length record file and storing it in the first data storage means; , a file access means for accessing data in the file;
File allocation from this file access means calls the file format conversion means based on a request, converts the variable length record file stored in the first data storage means into the file format of a fixed length record file, and a file allocation means for allocating a fixed length record file stored in a second data storage means; and a fixed length record file stored in the second data storage means based on a file read/write request from the file access means. File read/write means reads and writes data in a record file, and file allocation from the file access means is stored in the second data storage means by calling the file format conversion means based on a release request. and a file allocation/release means for converting a fixed length record file into a variable length record file file format, storing it in the first data storage means, and releasing the fixed length record file.

[Effect]

In the file format dynamic conversion method of the present invention, the first data storage means includes variable-length records, a record length storage section that records the record length of each variable-length record, and a file that records that the variable-length record is stored. A variable length record file consisting of a format recording section is stored, and the second data storage means stores a fixed length record, a file length certificate section for recording the total record length of the fixed length records, and a fixed length record. A fixed-length record file consisting of a file format recording section to be recorded is stored, and a file format converting means converts the variable-length record file stored in the first data storage means into the file format of the fixed-length record file to generate second data. A fixed-length record file stored in the storage means or a second data storage means is converted into a variable-length record file format, and the first
The file access means accesses the file data, and the file allocation means calls the file format conversion means based on a request from the file access means, and the first data storage means The variable-length record file stored in the storage device is converted into a fixed-length record file file format and stored in the second data storage means, the fixed-length record file is allocated, and the file read/write means reads the file from the file access means. The data of the fixed-length record file stored in the second data storage means is read and written based on a read/write request from the second data storage means, and the file allocation means handles the file allocation based on the release request from the file access means. A file format conversion means is called to convert the fixed length record file stored in the second data storage means into a file format of a variable length record file, and the file format is stored in the first data storage means, and the fixed length record file is released.

〔Example〕

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

FIG. 1 is a block diagram showing the configuration of a dynamic file format conversion method according to an embodiment of the present invention.

The dynamic file format conversion method of this embodiment includes a file access means 101, a file allocation means 102, a file allocation release means 103, a file read/write means 104, a file format conversion means 201, and a 1
Its main parts are composed of data storage means 301 and second data storage means 401.

The first data storage means 301 includes a file format recording unit 302 that records that variable length records are stored, a plurality of variable length records 303 to 306, and each variable length record 3.
A variable length record file consisting of a plurality of record length storage units 307 to 310 storing record lengths of 03 to 306 is stored. In addition, variable length records 303 to 30
At the end of 6, a new record symbol is recorded.

The second data storage means 401 includes a file format recording section 402 that records that fixed-length records are stored, a plurality of fixed-length records 403 to 405, and a fixed-length record 40.
A fixed length record file consisting of a file length recording section 406 that records the sum of record lengths 3 to 405 is stored.

The file access means 101 accesses data stored in a file, and requests the file allocation means 102 to allocate a file at the time it starts accessing the data of the file. In addition, file access means 1
01 requests the file allocation release means 103 to release the file at the time when access to the file data ends. Furthermore, the file access means 101 performs file read/write when reading and writing files.
The write means 104 is requested to read and write the file.

The file allocation means 102 converts the variable length record file stored in the first data storage means 301 into a fixed length record file file format and stores it in the second data storage means 401 at the start of file data processing. This request is made to the file format conversion means 201, and processing is performed to allocate the fixed length record file in order to use the fixed length record file stored in the second data storage means 401.

The file allocation release means 103 converts the fixed-length record file stored in the second data storage means 401 into a variable-length record file file format at the end of file data processing, and stores it in the first data storage means 301. The fixed length record file is released in order to release the allocation of the fixed length record file stored in the second data storage means 401.

Upon receiving a file read request from the file access means 101, the file read/write means 104 reads data from the position specified by the file access means 101 of the fixed length record file stored in the second data storage means 401. , the file access means 101 is notified. Further, when the file read/write unit 104 receives a write request to a file from the file access unit 101, the file read/write unit 104
The write data received from the receiver is stored in the second data storage means 40.
1 to the position specified by the file access means 101 of the fixed-length record file stored in 1.

When the file format converting means 201 starts data processing of a file, the file layout is changed from the variable length record file stored in the first data storage means 301 to the variable length record 303 in response to a request from the means 102. data whose record length is the value stored in the record length storage unit 307 and variable length records 304
The record length is stored in the record length storage section 308.
The data that is the value stored in variable length record 3
05 and the record length is record length storage section 3.
09 and the data stored in the variable length record 306 whose record length is the value stored in the record length storage unit 310 are read and concatenated, and the second data storage means The total record length of the concatenated data is recorded in the file length recording section 406 of 401, and the concatenated data is divided into fixed length records 403, 404 and 405 and stored in the second data storage means 401. 402 records that a fixed length record is stored. Furthermore, when the file format conversion means 201 finishes data processing of the file,
The file allocation is performed by the second
Fixed length records 403, 404 and 40 from the fixed length record file stored in the data storage means 401
5 is read out and concatenated, the data is recorded in the file format recording section 302 of the first data storage means 301, and the data is divided for each record change symbol according to the file format of the variable length record file. Variable length records 303, 304.30 of the first data storage means 301
5 and 306, respectively, and variable length records 30
3 in the record length storage section 307, the record length of the variable length record 304 in the record length storage section 308, the record length of the variable length record 305 in the record length storage section 309, and the data length of the variable length record 306 in the record length storage section 309. Each is stored in the record length storage section 310.

Next, the operation of the file format dynamic conversion method of this embodiment configured as described above will be explained with reference to FIGS. 2 to 4.

FIG. 2 is a diagram showing the movement of data and requests at the time when file data processing is started. When the file access means 101 is requested to use a file, it requests the file allocation means 102 to allocate the file (see reference numeral 501). The file allocation means 102 converts the file format of the variable length record file stored in the first data storage means 301 using the file format conversion means 20.
1 (see reference numeral 502). The file format conversion means 201 converts variable length records 303 and 30 from the variable length record file stored in the first data storage means 301.
4, Read 305 and 306 (see code 503)
, the variable length record file is stored in the second data storage means 401.
The file format of the fixed-length record file recorded in the file format recording section 402 is converted into the file format of the fixed-length record file, and the file format is written into the second data storage means 401 (see reference numeral 504). Specifically, the file format conversion means 201 converts the variable length record file stored in the first data storage means 301 into the variable length record 303 whose record length is the value stored in the record length storage section 307. Some data is stored in the variable length record 304 and the record length is the value stored in the record length storage unit 308, and data is stored in the variable length record 305 and the record length is the value stored in the record length storage unit 309. The data that is the stored value and the data that is stored in the variable length record 306 and whose record length is the value stored in the record length storage section 31O are read and concatenated, and the data that is the stored value is read and concatenated. The total record length of the concatenated data is recorded in the file length recording section 406, the concatenated data is divided into fixed length records 403, 404 and 405, and stored in the second data storage means 401, and the file format recording section 402
Records that fixed-length records are stored in . When the processing by the file format conversion means 201 is completed, the file allocation means 102 allocates the fixed length record file stored in the second data storage means 401 for use.

FIG. 3 is a diagram showing the movement of data and requests at the time when data processing of a file ends. When the file access means 101 is requested to release a file, it requests the file allocation release means 103 to release the file allocation (see reference numeral 505). File allocation is released by means 103
requests the file format conversion means 201 to convert the file format of the fixed-length record file stored in the second data storage means 401 (see reference numeral 506).

The file format conversion means 201 includes the second data storage means 4
Fixed-length records 403, 404, and 405 are read from the fixed-length record file stored in 01 (code 5
07), convert the fixed length record file into the file format of the variable length record file recorded in the file format recording section 302 of the first data storage means 301,
Write to the first data storage means 301 (see reference numeral 508)
.

Specifically, the file format conversion means 201 reads out and concatenates the data stored in fixed length records 403, 404 and 405 from the fixed length record file stored in the second data storage means 401, and converts the data stored in the first data storage The data is recorded in the file format recording unit 302 of the means 301, and the data is divided for each new record symbol according to the file format of the variable length record file, and the data is divided into variable length records 303, 304, 305 and 306 of the first data storage means 301. The record length of the variable length record 303 is stored in the record length storage section 307, the record length of the variable length record 304 is stored in the record length storage section 308, and the record length of the variable length record 305 is stored in the record length storage section 309.
Then, the data lengths of the variable length records 306 are stored in the record length storage section 310, respectively. File format conversion means 20
1, the file allocation release means I03 releases the fixed length record file stored in the second data storage means 401.

FIG. 4 is a diagram showing the movement of data and requests when file data is being read/written. When the file access means 101 is requested to read a file, it requests the file read/write means 104 to read data from the file (see reference numeral 509). When the file read/write means 104 receives a file read request from the file access means 101, the file read/write means 104 performs a second
Data is read from the position specified by the file access means 101 of the fixed length record file stored in the data storage means 401, and the file access means 1
Notify 01. The file access means 101 receives and receives read data notified from the file read/write means 104.

On the other hand, when file access means 101 is requested to write to a file, it passes the file write request and write data to file read/write means 104 .

When the file read/write means 104 receives a write request to a file from the file access means 101,
The write data received from the file access means 101 is written to the position specified by the file access means 101 of the fixed length record file stored in the second data storage means 401 (see reference numeral 510).

〔Effect of the invention〕

As explained above, in the case of accessing data in a variable-length record file at high speed, the present invention converts the file format of the variable-length record file to the file format of a fixed-length record file at the time of file allocation processing. By converting the fixed-length record file format to the variable-length record file format when the file data processing is completed and the file is deallocated, file data processing becomes more efficient. Data can be accessed in a fixed-length record file format with good quality, and there is no need to consciously convert the variable-length record file format before or after file data processing.

Another advantage is that there is no need to always manage whether the file to be accessed is a fixed-length record file.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a dynamic file format conversion method according to an embodiment of the present invention, and FIG. 2 is a point in time when data processing of a file is started in the dynamic file format conversion method of this embodiment. Figure 3 is a diagram showing the movement of data and requests at the time when file data processing is finished in the file format dynamic conversion method of this embodiment. FIG. 6 is a diagram showing the movement of data and requests when file data is being read/written in the file format dynamic conversion method of the present embodiment. In the figure, 101...File access means, 102...File allocation means, 103...File allocation release means, 104...File read/write means, 201...File format conversion means, 301 ... first data storage means, 302 ... file format recording section, 303 - 306 - variable length record, 307 - 310 - record length storage section, 401 ... second data storage means, 402 ... file Format recording section, 403-405 fixed length record, 406... file length recording section.

Claims (1)

[Claims] A file access method comprising a variable length record, a record length storage section for recording the record length of each variable length record, and a file format recording section for recording that the variable length record is stored. A first data storage means for storing a long record file, a fixed length record, a file length recording section for recording the total record length of the fixed length records, and a file format recording section for recording that a fixed length record is stored. a second data storage means for storing a fixed-length record file; converting the variable-length record file stored in the first data storage means into a file format of a fixed-length record file and storing it in the second data storage means; or the second
a file format conversion means for converting a fixed length record file stored in a data storage means into a variable length record file format and storing it in the first data storage means; and a file access means for accessing data in the file. and, based on the file allocation request from the file access means, calls the file format conversion means to convert the variable length record file stored in the first data storage means into a file format of a fixed length record file. a file allocation means for allocating a fixed length record file stored in the second data storage means; and a fixed length record file stored in the second data storage means based on a file read/write request from the file access means. file read/write means for reading and writing data in a record file; A dynamic file format conversion method characterized by comprising a file allocation release means for converting a long record file into a file format of a variable length record file, storing it in the first data storage means, and releasing the fixed length record file. .