JPS6284352A - File access controlling system - Google Patents

Abstract

PURPOSE:To reduce the number of times of accessing to a file by saving plural continuous page data sufficiently apart from present processing position to a file when the content of a controlling table became only such data that require renewal. CONSTITUTION:When all renewal bits of each page data of a controlling table 12n becomes '1', and becomes only the page data that require renewal, the second controlling table 13n in which form No in the case where a file 4 include plural imaginary forms and page No in the form is searched for each page data. The farthest address from the position of the page data being processed at present is extracted, and the plural page data that continue the page data are saved collectively in the file 4. Thus, replacing of the data in a page buffer can be speed up and the number of times of file access can be reduced without giving influences on the present processing position.

Description

[Detailed Description of the Invention] rWI Taken) The present invention provides a page buffer and a control table that indicates the state of update and reference of the page data between the information processing unit and the file that stores the page data of virtual paper. File access system, when the contents of the control table are only page data that needs to be updated, use the fill information in the second control table to move multiple consecutive page data sufficiently far away from the current processing position to the file. By performing save-through control, data replacement in the page buffer is speeded up and the number of file accesses is reduced by t.

[Industrial application field]

The present invention relates to an improvement in an access control method for a file that stores page data of virtual paper.

[Conventional technology]

Conventionally, under the control of an information processing unit, a page buffer is interposed between a file storing page data of a virtual paper (described later), such as an external storage device, and the page data is updated in accordance with input/output on both sides.

A control table is provided to indicate the status of the reference. A file has multiple sides of virtual paper, and each side is divided into 28 physical units of about 2KB and stored.
The p page buffer is passed between the p page buffer and the file by one or more pages.

FIGS. 3(cL) and (6) show an example of a conventional file access system of this type.

In the figure, the information processing unit 1 reads (
A request for reference) or write (update) is sent to the page buffer 3 via the control buffer 2. According to this request, the necessary address in file 4 is accessed and loaded into page buffer 6, and conversely, the page data to be updated written in page buffer 3 is saved to the corresponding address in file 4. .Control buffer 2 and page buffer 6
The number of page data required when processing file 4 is temporarily held. Control buffer 2 is shown in the same figure (6
) shows the control buffer 12n for each page, and the read corresponding to the requested page data.

In addition to storing the write address, the last two bits represent reference bits and update bits. For reference bits, 0" means not used, "1" means not being referenced, and for update bits, "0" means no writing is required, and 11 means writing is necessary. Page data corresponding to these addresses are temporarily held in the page buffer 5 as illustrated in the figure.

FIG. 4 is a flowchart showing the operation in the configuration of FIG. 6 (α). In the figure, 1) When the page data is on page buffer 3, there is no need to save to file 4 or load from file 4, and in the case of read, there is no change in the control table, and in the case of write, the update bit is not changed. Change ``@1'' to end the escape and move on to the next page data.

11) When the page data is not on the page buffer 3 and there is an update bit 10'', this becomes a candidate position for loading a new page from the file 4.The following procedure is the same as in I).

FIG. 5(α) shows an example of this case, where the mark indicates a candidate position for loading a new page.

iii) When the page data is not on the page buffer 6 and there is no update bit ``0'', save the file 4, free up an area on the page buffer 3, and then load.

Figure 5 (6) shows an example of this case.
), only the location with update bit 10# is subject to loading, and the update bit "1" increases with writing, so in the end all update bits are 11.
”.

[Problem that the invention seeks to solve]

When the state illustrated in FIG. 5(b) explained in the conventional example (mountain) above is reached, the update bits of the conventional control table,
Controlling save/load using reference bits alone is insufficient. In subsequent operations, a random save method is generally used, but this method cannot reduce the number of accesses to the file.

In this way, when the contents of the control table are only the page data that needs to be updated, the page buffer 3I/small-II
-) v to 1--54-Oha 1 Tsume Rushi is also good luck? Let's consider reducing the number of accesses to file 4 as well.

Therefore, the characteristics of the processing mode are as follows.

The 0th order processing page is frequently located before or after the page currently being processed (reference bit @1'').

(2) When one operation spans multiple pages, there is continuity and processing direction among those pages. Therefore, it is efficient to save/load multiple pages at once.

Utilizing these features, when the situation shown in Figure 5(b) occurs, it should be possible to safely/load multiple consecutive page data at positions sufficiently far away from the current processing position. be.

An object of the present invention is to provide file access control that speeds up replacement of page buffer page data and reduces the number of file accesses when the contents of a control table are only page data that needs to be updated. [Means for solving the problem] In order to achieve the above-mentioned object, the present invention provides a control system between the information processing unit and the file that indicates the update and reference status of page data. In addition to the table, a second control table is provided to control access (save/load) to the file when the contents of the control table are only page data that needs to be updated, and this processing information is used to This control is performed to save a plurality of consecutive page data sufficiently from the current processing position to a file.

[For production]

With the above configuration, in order to effectively overcome the situation where the conventional control table needs to be updated completely, for example, the page data position currently being processed (reference bit @ 1") Search the address in the second control table corresponding to each page data, select the one with the farthest address, extract the page data at this position and consecutive multiple page data, send them to a file and save. Do the following.

As a result, the update bits of these old areas change to @O", and new page data can be accepted.

〔Example〕

FIGS. 1(α) and 1(6) are configuration explanatory diagrams of embodiments of the present invention.

The difference from the conventional example shown in FIGS. 5(a) and 5(b) is the contents of the control buffer 11 shown in FIG. 5(6).

That is, in addition to the control table 12n showing the same update bits and reference bits as in FIG. 3, it also includes a second control table 13% which is the main part of the present invention. As shown in the same figure (b), the control table 13% prepares an area of 16 bits per word, writes paper A in the first 4 bits, and writes paper A in the case where file 4 includes a plurality of virtual papers, and then writes paper A in the first 4 bits as shown in FIG. Assume that the pagem in the paper is written in the bit.

Control table 12, same as the conventional example. However, for each page data, all update bits are 11 as shown in FIG. 5(b) above.
”, this second control table 16% is searched for each page of data.

Extract the one with the farthest address from the position of the page data currently being processed (reference bit @1"), and save this page data and multiple consecutive page data all at once to file 4. .In addition, when loading page data from file 4 to page buffer 3, the second
control table 13%.

In other words, in this case, for the current processing page data position,
Control table 1 for page data that corresponds to continuous multiple page data in the direction to the next processing page data
6. and loading is performed in accordance with this.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention.

In the figure, when the control buffer 11 is in the state shown in FIG. 5(cL), it is assumed that m pages from file 4 are currently being referenced. Then, as an example of processing, a bitmap figure (vector transport downward from page m) can be processed in the following steps.

(2) Start processing on page m on page buffer 3 and draw a straight line.

(2) Page +1 is on the page buffer 6, so move to page +1 and continue drawing straight lines.

(2) Since page m+2 does not exist on the page buffer 6, loading is necessary.

■Since 12% of the control tables all require updating,
It is necessary to save to file 4, and according to the contents of the second control table 16%, pages 4-1,i,<+1, located at the farthest position from the current processing position destination page, are saved all at once. In this case, only one access is required.

■Since the same processing is performed downward, there is a possibility that pages with Satoru+6 and below are also required, so the second control data.

Le 16. According to the contents of , I regret +2. Satoru +5. Load m+4 pages at once from file 4 to page number (sofa 6). In this case, access is only required once.

■? Continue straight line drawing for FL+2 pages and below.

〔Effect of the invention〕

As explained above, according to the present invention, when the content of the conventional control table is only page data that requires updating, the processing information of the second control table is used to This controls the saving of consecutive page data to a file. This saves multiple consecutive pages of data that are far enough away from the current processing position to a file all at once, which speeds up data replacement in the page buffer and reduces the number of file accesses without affecting the current processing position. This can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, FIG. 2 is an explanatory diagram showing an example of the operation of the embodiment, and FIG. M3 is an explanatory diagram of the configuration of a conventional example.
Fig. 5 is an explanatory diagram of the operation of the conventional example, and Fig. 4 is a flowchart showing the operation of the conventional example. 12,
indicates a control table, and 13n indicates a second control table. Operation example 1 of the embodiment of the present invention: jiffi @ mth
Figure 2: Diagram for explaining the operation of the conventional example Figure 5: Flowchart showing the operation of the conventional example A M

Claims (1)

[Claims] A page buffer that temporarily holds multiple pages required for read/write requests from the information processing unit is provided between the information processing unit and the file that stores page data, and page data is transferred between the page buffer and the file. (save/
In a file access system that has a control table that indicates the update and reference status for (load), if the contents of the control table are only page data that requires updating, the address location is sufficiently far away from the current processing location. A file access control method further comprising a second control table storing information for saving a plurality of consecutive page data to a file.