JPS61100847A - System for managing page of data accumulating file - Google Patents

Abstract

PURPOSE:To eliminate the necessity of data transmitting/receiving operations to be performed between an external storage device and CPU whenever a page is newly registered or released, by using a bit map table which manage the use/un-use pages. CONSTITUTION:When a newly registering a request of a page is made, the page corresponding to the smallest page number among unused pages is selected as the page for the new registration and the logical value of the storage element at the bit position corresponding to an unused page number (NOUSEP)2 in a bit map table 1 is set at '1'. Then the used page number (USENUM)4 is increased by '1', since the used page is increased by one page. Then the maximum page number (MAXPAG)3 is compared with the USENUM4 and, when the latter is greater than the former 3, the MAXPAG3 is updated by '+1'. Updating of the NOUSEP2 is performed by retrieving the minimum unused page from the bit map table.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention describes the order in which records are read. This invention relates to a page management method for data storage files using file formats that may be formatted as files.

(Prior art) Conventionally, the page management of this cage is based on the page number of the most recently deleted and released page, the largest page number among the currently used pages, and the chain stored in the released page. This is done using the page number of the page that was released immediately before that, which is connected with the page number.

Figure 4 is an explanatory diagram of the conventional method. Figure 4(a).

(b) and (C) show an external storage device 41 and a deletion page number register 42 in the central processing unit connected thereto.

In FIG. 4(a), the page number 11 of the most recently deleted and released page is in the deleted page number register 4.
2, and the page corresponding to page number 11 of the external storage device 410 stores the page number 26 of the page deleted and released one page before page number 11, and the page number 26 of the page deleted and released one page before page number 11 is stored. The page corresponding to page number 26 stores the page number 37 of the page deleted and released one page before page number 26, and the page corresponding to page number 37 stores the page number of the page deleted one page before that. O is stored as . Since page number O does not exist, this clearly indicates that the page corresponding to page number 37 is the first page to be deleted and released.

FIG. 4(b)K shows the situation when the page number of the newly registered page is selected when the page number of the page most recently deleted and released is 11.

In other words, when there is a request to register a new page, @K
Check the deletion page number register 42, and if the page number stored there is not 0, select the page corresponding to that page number (11 in this case) as the new registration page, and select the page corresponding to page number 11. Page number 26t corresponding to the page deleted and released one page before the page corresponding to stored page number 11 - read from external storage device 1 and deleted page number register 42
Store and update VC.

FIG. 4(C) shows a situation where the page number of the page most recently deleted and released is 26, and a new page (14 in this case) becomes unnecessary and is released.

That is, when there is a new page release request, the page number 26 stored in the deletion page number register 42 is stored in the external storage device 410 page corresponding to the page number 14 to be newly released, and then the page number 26 stored in the deletion page number register 42 is stored in the external storage device 410 page corresponding to the page number 14 to be newly released. Rewrite the content from 26 to 14.

(Problems to be Solved by the Invention) As explained above, in the conventional system, each time a new page is registered or a page is released, communication between the external storage device and the central processing unit is There is a problem in that it is necessary to perform all the data transmission and reception operations, which significantly slows down the data processing speed.

Therefore, in the present invention, by using a bitmap table that manages page use/unuse (unused means released), each time a new page is registered or a page is released, This is intended to significantly improve data processing speed by eliminating data transmission and reception operations between an external storage device and a central processing unit.

(Means for Solving All Problems) The method of the present invention is a data storage file in which a page serving as an input/output unit of a data storage file is managed by a page number that has a one-to-one correspondence with a page storage location of the file. In the page management method, an entire bitmap table having information indicating all used and unused pages corresponding to the page number is stored in a specific storage location of the file in advance, and when the file is used, the bitmap table is stored in the central processing unit. When registering a new page for use, select for full use the page corresponding to the smallest page number among the unused pages, and correspondingly select the page corresponding to the smallest page number from the bitmap table. All information on the page corresponding to the number is updated from an unused display to a used display within the central processing unit, and when a page is released, all information on the bitmap table corresponding to the page number to be released is used within the central processing unit. The display is updated to an unused display, and when the use of the file is finished, all the updated bitmap tables stored in the internal storage are transferred to a specific storage location of the file and released.

(Example) Next, an example of the present invention will be described in detail with reference to the drawings.

Is Fig. 1 an embodiment of the present invention? FIG. The page management system for the data storage file shown in FIG. 1 is managed using a bitmap table 1, an unused page number 2, a maximum used page number 3, and a used page number 4.

A page, which is a data input/output unit between a file in an external storage device and an internal storage in a central processing unit, is managed by a page number that has a one-to-one correspondence with the storage location of the file.

Bitmap table 1 is prepared corresponding to one file, one page is associated with one piece of storage information, and the bitmap table 1 is arranged in order of page number j. If a certain page is being used, the corresponding storage information will be a logical value @1.
# is indicated, and non-use is indicated by the storage information indicating a logical value "O".

The unused page number (hereinafter referred to as N0USEP) 2 is the smallest page number among the unused pages.

Maximum used page number (hereinafter referred to as MAXPAG) 3 is the largest page number among the pages currently in use? say.

The number of pages in use (hereinafter referred to as U8ENUM) 4 refers to the number of pages currently in use.

Each file in the external storage device has a bitmap table l corresponding to the file and the above three pieces of information, namely N008EP2 and MAXPAG, in a specific location.
3 and USENt7Ms are stored.

When the external storage device is connected to the central processing unit and files are used, the bitmap table 1 and NOU described above are used.
Transfer SEP2, MAXPAG3 and USENUM4 from the file to the internal storage of the central processing unit.

Hereinafter, page management operations within the central processing unit will be described in detail for the case of new page registration and the case of page release 2''2.

Figure 2 is a flowchart showing the operation when registering a new page. When a new page registration request is made, the page corresponding to N0USEP2, that is, the lowest page number among unused pages, is selected as the page for new registration, and N0USEP2Vc in bitmap table 1 is selected.
The logical value of the storage element of the corresponding bit is set to @1'' (step 21).

Then the number of pages used increased by one, so U 8 E N
Add 1 to UM4 (step 22). Next is MAXPAG
3 and USE'NUM4, and if USENUM4 is large, MAXPAGae+I is updated (step 25). N0USEP2 is updated by searching the bitmap table for the smallest page number among unused pages (step 24).

FIG. 3 is a flowchart showing the operation when releasing a page. The logical value of the storage element at the bit position of bit map table 1 corresponding to the page number for which the release request was made is set to @0' (step 31).

Then, the number of pages used decreased by one page, so US ENU
M4 is decremented by -1 (step 32). In step 33), when N0USEP2 is thick, the value of N008EP2 is updated to the page number of the released page. (Step 34). Next, compare the page number of the released page with MAXPAG3 in step 35) 1
If they are equal, the maximum page number among the pages in use is retrieved from bitmap table 1, and MAXPAG3t- is updated with this value (step 36).

As described above, when a new page is registered and released, only data processing is performed within the central processing unit, and there is no transfer of data related to page management to or from an external storage device.

When the file in the external storage device is separated from the central processing unit, the bitmap table N0USE'P stored in the internal storage of the central processing unit is used.

The management data of MAXPAG and UiSENUM is transferred and stored in a predetermined area of the file, and becomes the management data when the file is used next time.

In this embodiment, the information to be transferred for page management between the external storage device and the central processing unit is explained as a bitmap table, N0tJSEP, MAXPAG, and USENUM, but the bitmap table includes N0U8.
Since EP, MAXPAG and USENUM information are included, it is clear that the same effect can be obtained by just transferring the bitmap table.

(Effects of the Invention) The present invention has the following features: By storing a bitmap table in all internal storage locations for managing page number use/unuse.
When selecting a newly registered page number and releasing a page number that is no longer used, there is no input/output of page management data to/from the file, and the data processing speed can be greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an embodiment of the present invention, and Fig. 2 is a diagram showing information changes in Fig. 1 when a new page is registered.
) is an explanatory diagram completely explaining the conventional page management method. 1... Bit Matsubuchi i pull, 2...
Unused page number (NOUSEP), 3...
Maximum used page number (MAXPAG), 4...
Number of pages used (USENUM), 21-25.31-3
4... Step of the flowchart, 41...
. . . External storage device, 42 . . . Deletion page number register (DELPAG). Conflict 21 ^ Child 51121 Mine 4 - Diagram (b) (C)

Claims (1)

[Scope of Claims] In a page management method for a data storage file in which a page serving as an input/output unit of a data storage file is managed by a page number having a one-to-one correspondence with a page storage location of the file, the file is specified in advance. A bitmap table having information indicating whether the corresponding page is used or unused in the order of the page number is stored in the storage location of the page number, and when the file is used, the bitmap table is transferred to the internal memory of the central processing unit, and a new page is created. When registering for use, a page corresponding to the lowest page number among the unused pages is selected for use, and correspondingly, information on the page corresponding to the lowest page number in the bitmap table is processed by the central processing. updating from an unused display to a used display in the device, and when releasing a page, updating information in the bitmap table corresponding to the page number to be released from a used display to an unused display in the central processing unit; A page management method for a data storage file, characterized in that the updated bitmap table stored in the internal storage is transferred to a specific storage location of the file upon completion of use of the data storage file.