JPH04270429A - Data erasing system for hyper structure data - Google Patents

Abstract

PURPOSE:To erase data successively from a high-order data, to unnecessitate the use of a recursive program and to prevent the danger of stack overflow concerning the data erasing system of the hyper structure data. CONSTITUTION:At the data erasing system of the hyper structure data to erase the arbitrary data from a hyper structure data 1 constituted by linking the data to the plural high-order or low-order data, a link information erasing means 2 erases the link information of the data designated erasing with the low-order data. A file writing means 3 writes the link information erased by the link information erasing means 2 in a link data list file 4. A file reading means 5 reads the data designated by the link information written in the link data list file 4 and informs it of the link information erasing means 2. Thus, the data designated by all the link information in the link data list file 4 are successively erased.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a data deletion method,
The present invention relates to a data deletion method for deleting hyperstructure data.

0002

[Prior Art] Conventionally, data D3 as shown in FIG.
Hyper-structured data is formed by linking the data with higher-order data D1 and D2 and with lower-order data D4, D5, and D6.

Each of the above-mentioned data D1 to D6 etc. is composed of a data management file and a media file, and the media file is composed of a text data file, a vector data file, an audio data file, an image data file, etc.

[0004] As shown in FIG. 6(A), the data management file includes data numbers, each media information, date and time of creation, date and time of last update, attributes, and display coordinates, as well as link information 10a with upper-level data and link information 10b with lower-level data.
is stored. As shown in FIG. 6(B), link information 10a with higher-level data includes the number of links and the data number of each link partner. As shown in FIG. 6C, the link information 10b with lower data includes the number of links, the data number of each link partner, link coordinates X and Y indicating rows and columns, link date and time, and attributes.

FIGS. 7A and 7B are flowcharts of an example of a conventional data deletion method for hyperstructure data. When the deletion command and data name are input in step 19 of FIG. 7(A), a link data check routine is executed in step 20. In the link data check routine shown in FIG. 7(B), the data management file of the data specified for deletion is opened (step 21), and the higher-order data linked to the data specified for deletion is canceled (step 22). ). Next, it is determined whether the specified data is linked to another higher-level data (step 23), and if so, the data management file is closed (step 24) and the process ends. If it is not linked to another higher-level data, determine whether the lower-level data is linked to the specified data (step 25).
, if there is a link with lower-order data, the link data check routine (step 27) is repeated at step 26 until the number of links with lower-order data becomes 0. When the number of links becomes 0, the data management file is closed in step 28 and the management and media files are deleted (step 2
9) End the process.

[0006]

[Problem to be Solved by the Invention] In this way, when deleting link data in which a plurality of related data are associated in the form of links and have a hyper structure, first the two data in the link relationship are Release the link status by deleting the link information of the management file, and then delete the management file and each media file of the specified data. If other data is linked to the data to be deleted at this time, the data linked to the specified data will be deleted in the same way, but if the linked data is In some cases, the linked data may be linked to other data, so the link status of the linked data must also be investigated, and the hierarchy is deep. To delete data that has a link relationship such as Not only does this result in a program with a deep recursive structure that is difficult to understand, but there is also the risk of stack overflow of the stack that stores the return address.

The present invention has been made in view of the above points, and is a data deletion method for hyper-structured data that allows data to be deleted in order from the upper level data, eliminates the need to use a program with a recursive structure, and eliminates the risk of stack overflow. The purpose is to provide a method.

[0008]

Means for Solving the Problems FIG. 1 shows a diagram of the principle of the present invention.

In the figure, hyper-structure data is constructed by linking data with a plurality of higher-order data or lower-order data.

[0010] The link information deletion means 2 deletes the link information between the data designated for deletion and the subordinate data.

The file writing means 3 writes the link information deleted by the link information deletion means 2 into the link data list file 4.

The file reading means 5 reads the data specified by the link information written in the link data list file and notifies the link information deletion means 2 of the data.

Data specified by all the link information in the link data list file 4 is sequentially deleted.

[0014]

[Operation] In the present invention, the link information deletion means 2 deletes the link information of lower-order data, this link information is temporarily written in the link data list file 4, and the file reading means 5 writes the link information from the link data list file 4. Since the link information is read out sequentially and notified to the link information deletion means 2, the data can be deleted in order from the upper level data, which eliminates the need to use a program with a recursive structure, and there is a risk of stack overflow of the stack that stores the return address. disappears.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows a flowchart of an embodiment of the method of the present invention.

In the figure, when a deletion command and its data name are input in step 40, the data management file of the specified deletion data is opened in step 41, and the link information with the currently linked upper data is stored. Delete and unlink. At this time, link information with the deleted data in the management file of the higher-level data is also deleted at the same time. Next, it is determined whether the deleted data is linked to other higher-level data (step 42), and if there is a link, the data management file is closed (step 43), and the process ends. If there is no link with higher-level data, a link data list file is created and opened (step 44), and a link data list file writing routine is executed in step 45.

FIG. 3 shows a flowchart of the link data list file writing routine. In the figure, step 60
Now, link information 10b with lower-level data in the management file.
Check the data to be linked one by one until the number of links becomes 0, and if the number of links is not 0, step 61
First, delete the link information of the deleted data, and then delete the link information between the lower data and the deleted data in the data management file. In step 62, the link information of the deleted lower data is written to the link data list file shown in FIG. 4, in step 63 the write offset (write address) of the link data list file is updated, and in step 64 the lower data of the deleted data The number of links in the link information 10b is decreased by 1 and the process returns to step 60.

By repeating steps 60 to 64 above, if the number of links with lower-order data in the data management file of deleted data is N, the 1st to Nth link information in the link data list file of FIG. 4 is written. It will be done.

At step 46 in FIG. 2, the data management file for the deleted data is closed and the data management file and media file for the deleted data are deleted.

Next, in step 47, the number of links in the return value from the link data list file writing routine is determined, and if this number of links is 0, the link data list file is determined to be EOF (end of file) in step 48. The processing from step 49 onwards is executed until the result is reached.

In step 49, one piece of link information is read from the link data list file, and in step 50, a data management file for the data specified by this link information is opened.

[0022] Next, it is determined whether the data specified by this link information is linked to other higher-level data (
In step 51), if there is a link, the data management file is closed (step 54), and if there is no link with higher-level data, a linked data list file writing routine is executed in step 52.

Thereafter, in step 53, the data management file is closed, and the data management file and media file of this data are deleted.

After step 53 or 54, step 55
Then, the read offset (read address) of the link data list file is updated, and the process returns to step 48.

[0025] If the link data list file becomes EOF by repeating steps 48 to 55, or step 47
If the number of links is 0, proceed to step 56, close the link data list file, and proceed to step 5.
At step 7, the link data list file is deleted and the process ends.

In this way, the link information of the lower-order data is deleted, this link information is temporarily written in the link data list file, and the link information is sequentially read out from the link data list file 4, and the lower-order data of this link information is Since link information is repeatedly deleted, data can be deleted in order starting from the upper data, which eliminates the need to use a program with a recursive structure, and eliminates the risk of stack overflow of the stack that stores the return address.

[0027]

[Effects of the Invention] As described above, according to the data deletion method for hyperstructure data of the present invention, it is possible to delete data in order from the upper level data, and there is no need to use a program with a recursive structure. There is no risk of overflow, and it is extremely useful in practice.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the present invention.

FIG. 2 is a flowchart of one embodiment of the method of the present invention.

FIG. 3 is a flowchart of a link data list file writing routine.

FIG. 4 is a diagram showing a link data list file.

FIG. 5 is a diagram showing hyperstructure data.

FIG. 6 is a configuration diagram of a data management file.

FIG. 7 is a flowchart of an example of a conventional method.

[Explanation of symbols]

1 Hyper structure data 2 Link information deletion means 3 File writing means 4 Link data list file 5 File reading means

Claims (1)

[Claims] Claim 1: In a data deletion method for hyper-structured data that deletes arbitrary data from hyper-structured data (1) configured by linking data with a plurality of higher-order data or lower-order data, Link information deletion means (2) for deleting link information with data
, file writing means (3) for writing the link information deleted by the link information deletion means (2) into the link data list file (4), and the link data list file (4).
), the file reading means (5) reads out the data specified by the link information written in the link information and notifies the link information deletion means (2), and all the links in the link data list file (4) are read out. A data deletion method for hyperstructure data characterized by sequentially deleting data specified by information.