JPH04165542A - Electronic filing device - Google Patents

Abstract

PURPOSE:To improve the use efficiency of a disk so that a page erased once can be reset by recording information of a page to be erased in an (erased page management table), resetting the page erased once and executing disk condensation, when a magneto-optical disk becomes a full state. CONSTITUTION:In the case an erasure of a page is generated, a (page number) at the time of erasure of the page concerned, a (store start sector number) of page data, and a (store sector number) are stored in an (erased page management table). In this case, page information in a (page management table) is only shifted into the (erased page management table), and a data store sector of the page to be erased is still in a state of using. Also, in the case a disk 3 becomes a full state, the (erased page management table) of all documents is referred to by a means 7 for executing disk condensation, the sector in which the erased page is stored is opened, and the succeeding page information which is not erased is shifted successively to a front free sector. In such a way, the disk 3 can be used efficiently, and also, the page erased erroneously can be reset.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an electronic filing device that can easily restore pages that have been erased by mistake and that can prevent fragmentation of a magneto-optical disk that occurs when pages are erased. It is.

(Prior Art) In recent years, there has been an increase in the number of devices that store document information as a database on magneto-optical disks and search and utilize this information. When registering a document, these devices generate a free bitmap representing the usage status of all sectors on the disk, as shown in Figure 2(a), and a free bitmap for each registered document, as shown in Figure 2(b). A "page management table" for managing page information is stored on a magneto-optical disk. The "page management table" allows you to know where page data is stored on the disk. On the other hand, each bit of the free bit map corresponds to a sector of the data area of the magneto-optical disk in a one-to-l ratio, and if this value is zero, it indicates that the corresponding sector is unused; indicates that it is in use. Conventionally, when deleting an arbitrary page of a document that has already been registered, the information on the corresponding page in the "page management table" is deleted, and at the same time, the information in the free bit map corresponding to the sector in which the page to be deleted is stored is deleted. The bit value was set to zero (representing unused).

(Problem to be Solved by the Invention) However, with the above conventional methods, fragmentation occurs in which unused sectors are scattered on the disk every time a page is erased, which reduces the efficiency of disk usage. This will lead to a decrease in search speed. Another problem with this method is that it is impossible to restore a page once it has been erased.

The present invention solves the above-mentioned conventional problems, and aims to provide an electronic filing device that has good disk usage efficiency, high search speed, and is also capable of restoring deleted pages. It is something.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an electronic filing device that includes a means for recording page information of a document in a "page management table" and a means for recording page information of a document in a "page management table". A means for deleting pages using a table, a means for recording information about pages to be deleted in an erased page management table, a means for restoring a page once erased by referring to an erased page management table, When the magnetic disk becomes full, it refers to the "erased page management table" and performs disk condensation, and when a page is erased, the "
The ``page number'', ``storage start sector number'' and ``storage sector number'' of page data at the time of erasing the corresponding page are stored in the ``erased page management table'', and in this case, correspond to the storage sector of the erased page. The value of the bit in the free bitmap is l
Leave as is (indicating that it is in use). Furthermore, when the disk becomes full, the user issues a disk condensation command, and by means of disk condensation, the erased page management table of all documents is referred to and the erased pages are stored. open the sectors that have been
The subsequent unerased page information is sequentially moved to the front empty sector.

(Function) Therefore, according to the present invention, when deleting a page, "
The page information in the ``page management table'' is only moved to the ``erased page management table'', and the data storage sector of the page to be erased is still in use. Therefore, disk fragmentation does not occur and disks can be used efficiently. Furthermore, it is possible to restore pages that have been deleted by mistake.

Also, by disk condensation, continuous free sectors can be secured within the disk.

(Embodiment) FIG. 1 shows a block configuration of an electronic filing device in an embodiment of the present invention. In FIG. 1, 1 is a central processing unit that controls each device and makes logical decisions, 2 is a magneto-optical disk device that reads and writes data on a magneto-optical disk, 3 is a magneto-optical disk, 4 is a document reading device, and 5 is a magneto-optical disk. A main memory, 6 a display device, and 7 a keyboard input device.

Next, the operation of the above embodiment will be explained. At the time of registration, the document reading device 4 reads the data of each member of the document into the main memory 5, and the data is read into the magneto-optical disk via the magneto-optical disk device 2 while referring to the free bit map shown in FIG. 2(a). Write sequentially from the empty sector at the beginning of page data area No. 3. At this time, create a "page management table" as shown in Figure 2 (b), and register each member's "storage start sector number" and "storage sector number", which also applies to the magneto-optical disk. It is stored in the control data area on the magneto-optical disk 3 via the device 2. At the same time, set the value of the free bitmap bit corresponding to the used sector to 1.
(represents in use).

Here, let's assume that a page with a page management table J as shown in Figure 4 is
Suppose we have a document consisting of pages. When page 2 is to be erased here, an "erased page management table" for this document is first created in the control data area on the magneto-optical disk 3. Then, as shown in Figure 5, the "page number" of entry O in this table
2 is stored in [Storage start sector number 1], 17 is stored in ``Storage sector number j'', and 3 is stored in ``Number of storage sectors j. At this time, the value of the free bitmap bit corresponding to the sector where the erased page data is stored is 1 ( (indicates that it is in use).

By doing this, the data on the erased page will not be destroyed. Also, for the "Page management table", the 6th
Entry 2 is erased by sequentially moving all entries after entry 3 forward one position as shown in the figure.

Furthermore, when restoring a page that has been previously erased, the operation reverse to that for erasing is performed. This will be explained using the flowchart in FIG. That is, in step 1 (S,), the user selects the document and its page number to be returned to using the keyboard input device 7, and in (S3) the number of the page to be returned to is entered into a variable P. In (S,), the number of the entry in the "erased page management table" in which information about the page to be restored is stored is stored in the variable E. On the other hand (S4), the number of all the members of the designated document that has not been deleted is stored in a variable N. In (S,), check the magnitude relationship between N and P, and if N)P, proceed to (S,), and if N≦P, proceed to (S,). In (S,), all entries after entry P in the "page management table" are sequentially moved backward one by one. At (S,), the value of variable N is substituted for variable P, and the process returns to S,).

In (S,), the ``storage start sector 1 number'' of entry E in the ``erased page management table'' is set to ``storage start sector 1 number J'' of entry P in the ``page management table.'' In (S,), The "number of storage sectors" of the entry E of the "erased page management table" is stored in the "number of storage sectors" of the entry P of the "page management table".

Finally, at (S, . . .), entry E is deleted by sequentially moving all entries after entry (E+1) in the "erased page management table" forward one by one.

When condensing a magneto-optical disk, the user first inputs a condensation command using the keyboard input device 7. Therefore, the central processing unit 1 checks all the "erased page management tables" in the disk and tells the display device 6 how many bytes of free area will be secured if all the sectors recorded there are released. indicate. Therefore, when the user uses the keyboard input device 7 to issue a condensation execution command to the own device, condensation is actually performed. That is, all "page management tables" and "erased page management table J" recorded in the control data area of the magneto-optical disk are checked, and unerased pages are stored in sectors where data of erased pages are stored. Transfer the data sequentially. As a result, the value of the bit in the free bitmap corresponding to the empty sector is set to zero (representing unused). At this time, all "erased page management tables" recorded in the control data area of the disk are also cleared.

(Effects of the Invention) As is clear from the above embodiments, the present invention can prevent disk fragmentation when deleting registered pages, and can effectively use the disk. has excellent access.

Furthermore, it is also possible to easily restore data on a page that has been deleted by mistake.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an electronic filing device according to an embodiment of the present invention, and FIG. 2(a). (b) is a diagram showing the free bitmap and "page management table" used in the conventional and the present invention, FIG. 3 is a diagram showing the "erased page management table" used in the present invention, and FIGS. 4 and 6 are FIG. 5 is a state diagram of the "page management table" according to an embodiment of the present invention, FIG. 5 is a state diagram of the "erased page management table" according to an embodiment of the present invention, and FIG. 7 is an erase diagram of an embodiment of the present invention. It is a flowchart of completed page return processing. DESCRIPTION OF SYMBOLS 1... Central processing unit, 2... Magneto-optical disk device, 3... Magneto-optical disk, 4... Document reading device, 5... Main memory, 6... Display device, 7...・Keyboard input device. Patent applicant: Matsushita Electric Industrial Co., Ltd. Agent: Tsukasa Hoshino - Figure 1 Figure 2 (a) (b) Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] means for recording page information of a document in a "page management table"; means for deleting information on pages to be deleted from the "page management table"; and recording information on the pages to be deleted in an "erased page management table". means for restoring a once erased page by referring to the "erased page management table"; and means for restoring a page once erased by referring to the "erased page management table" when the magneto-optical disk becomes full. An electronic filing device comprising means for performing disk condensation.