JPH0656591B2 - Data editing processor - Google Patents

Description

The present invention relates to a data edit processing device, and more particularly to a list structure even when an accident such as a power failure occurs during execution of data edit processing and the edit processing must be interrupted. The present invention relates to a data edit processing device that prevents data from being destroyed.

Conventionally, in a small computer system, if an accident such as a power failure occurs during execution of the data edit processing device, after the recovery of the accident, data destruction is detected by a Samchieck error etc., and the data file is recreated from the beginning. It was normal. Also, in a large computer system, when an accident such as a power failure occurs, the information necessary for resuming data editing processing after the accident is recovered is saved in a predetermined non-volatile memory at the time of the accident and the accident occurs. The time required for the system to operate from the time of occurrence until the end of information saving depends on a large storage battery or a private generator.

However, in recent years, the price of storage devices has been reduced, and magnetic bubble memories, magnetic disk devices, etc. have been introduced into inexpensive small-sized computer systems, and their storage capacities are increasing. In such a small computer system of recent years, when an accident such as a power failure occurs while executing the data editing process, it takes a lot of time and it is not easy to re-edit all from the beginning like the conventional system. .
In addition, providing a backup power supply to save the information required for restarting editing processing in the event of a power outage, like a large computer system, will lead to an increase in price and at the same time necessitate new maintenance such as storage batteries. There are drawbacks.

The present invention has been made in view of the drawbacks of the conventional data edit processing device. When the edit processing is interrupted due to an accident such as a power failure during the execution of the data edit processing, the interrupted edit processing operation is started. Instead of re-editing everything from the beginning when recovering from an accident, without destroying the list structure of the state immediately before it was started, it is possible to return to the state immediately before the interrupted editing process was started and restart the editing operation. An object of the present invention is to provide a data editing processing device.

A data edit processing device of the present invention is a device for connecting data in a circular list structure or a chained list structure by a pointer and executing a data edit process, for saving the data content immediately before the edit process. The first pointer group, the second pointer group for executing the editing process, and the first pointer group are selected while the second pointer group is executing the editing process. Is composed of a pointer selector for selecting the second pointer group after the editing process is completed.

That is, in order not to cause confusion in the data group even if the editing processing such as data addition, deletion, and rearrangement is terminated,
It is sufficient to create new data while preserving the data before editing, and to add a heading as the latest data to this new data after the new data is completely prepared. However, to execute this as it is, a storage capacity twice as much as the required data amount is required, resulting in extremely low efficiency.

Therefore, in the present invention, a method of connecting data with a circular list structure or a chained list structure using pointers is adopted, and a first pointer group for storing data before editing and an actual editing operation are performed. A second pointer group is provided to reduce the storage capacity. After the editing process is completed in the second pointer group, the pointer selector selects the second pointer group so that even if an accident such as a power failure occurs during the editing process operation, it is possible to perform Since the data is saved, the editing process can be resumed immediately after the accident recovery.

Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the accompanying drawings.

FIG. 1 is an explanatory diagram of a data file showing an embodiment of the present invention. This data file contains the data block (B0
~ B7) data group DG, pointers (H0, H1, C0 to C7) 2 sets of pointer groups P0, P1 and these 2 sets of pointer groups P1 and P2 are currently valid And a pointer selector S indicating whether or not The data group DG can arbitrarily select the number of blocks (8 blocks in this embodiment) or the number of 1 block depending on the specifications of the storage device or system. Further, the pointers C0, C1, ..., C7 of the pointer groups P0, P1 respectively indicate the data blocks next to the data blocks B0, B1, ..., B7 of the data group DG. For example, the contents of the pointer C0 When is "2", it indicates that the data block B0 is followed by the data block B2. The data blocks B0, B1, ..., B7 are connected in a single ring according to the instruction contents of the pointers C0, C1 ,. The pointer H0 points to the head block of the data blocks containing significant data among the data blocks B0, B1, ..., B7 connected in a ring, and the pointer H1 also points to the data blocks B0, B1 ,. , B7, the first data block of an empty block is designated. In the present invention, when the pointers C0, C1, ..., C7 are used to point the data blocks B0, B1 ,.
Continuous data blocks containing significant data,
At the same time, you are instructed to continue blank data blocks. It suffices that each pointer H0, H1, C0, ..., C7 has a bit number capable of displaying one data block. For example, if there are eight data blocks, pointers H0, H1, C0 Etc. may be of a size capable of expressing a numerical value of 0 to 7.

In the pointer selector S, the current data file is P0, P1.
The pointer group P0 is used for reading data when the content of the pointer selector S is "0", and the pointer group is used for editing data. group
It shows that P1 should be used.

Next, the operation of the embodiment shown in FIG. 1 will be described. First
As shown in the figure, the data blocks B0, B1, ..., B5 have data “d”, “f”, “a”, “b”, “e”,
"H" is stored, and the data blocks B6 and B7 are blank blocks. Further, "2" is stored in the pointer H0 of the pointer group P0, and "6" is stored in the pointer H1.
Is stored. Therefore, in the circular connection of the data blocks B0, B1, ..., B7 formed by the instruction contents of the pointers C0, C1, ..., C7 of the pointer group P0, the first significant data is stored. It can be seen that the data block is B2 and the first blank block is B6. Further, as shown in the figure, each pointer C0, C of the pointer group P0
Numbers for instructing a data block and forming a ring connection are stored in 1, ..., C7.

The data read operation will be described under the above premise. First, since the content of the pointer selector S is "0", the pointer group P0 is referred to. Since the content of the pointer H0 in the pointer group P0 is "2", it can be seen that the first block in which significant data is stored is the data block B2. The content of the data block B2 is "a", and this is read first. Then, the content of the pointer C2 that points to the next data block of the data block B2 is "3", which indicates that the data block B2 is followed by the data block B3. The content of the data block B3 is "b", and this is read next. Then, because it is the content 5 of the pointer C3 that points to the next data block of the pool block B3,
As a result, the data block B3 is followed by the data block B5.
It can be seen that it is. The contents of data block B5 are "C".
And this is read. Similarly, B5 → C5 (0)
→ B0 (d) → C0 (4) → B4 (e) → C4 (1) → B1 (f) → C1 (6) → B6 in this order, data “d”, “e”, and “f” are read. Be done.

When the data block B6 is specified by the pointer C1,
Since it is found from the pointer H1 that the data block B6 is the first block of the blank block sequence, it can be seen that the significant data block sequence ends at the data block B1.

Significant data blocks B2, B3, B5, B0, B4, B
The contents of 1 are read out sequentially and the data “a”, “b”,
"C", "D", "E", and "F" are read out.

Next, a general data string editing process will be described. Editing a general data string is realized by inserting arbitrary data into the data string, deleting arbitrary data in the data string, combining this data insertion and data deletion, and repeating these operations. Therefore, in the following explanation, a new data “to” is added to the data block B6 which is a blank block.
Will be described, and when the data block is stored and moved into the data block sequence, one data block is deleted from the data block sequence, and this data block is moved into the blank block sequence.

In the first case, as shown in FIG. 2, the new data “TO” stored in the blank block B6 is changed to the current significant data string (A,
Insert the data string (a, b, d, h)
C, C, D, H, F) are generated. In this case, the data string (a, b, ha, t, d, h, f) changes the content of the pointer C1 from "6" to "7", and the pointer C5
By changing the contents of the pointer from "0" to "6", changing the contents of the pointer C6 from "7" to "0", and further changing the contents of the pointer H1 from "6" to "7". It is easy to see what can be achieved. So this new pointer H0, H1,
The contents of C0, C1, ..., C7 are created in the pointer group P1 not currently selected by the pointer selector S. After the creation processing in the pointer group P1 is completed and the content shown in FIG. 2 is reached, the content of the pointer selector S is set to "0".
Is changed to "1" and the operation ends.

If there is no blank data block in the data group DG, it is impossible to execute the data insertion process. In this case, as is apparent from the above description, the content of the pointer H1 becomes "8", and the final data block B7
The instruction number of "7" is exceeded. Therefore, by comparing the content of the pointer H1 with the instruction number of the final data block B7 prior to the data insertion processing, it is possible to easily determine whether or not the data insertion processing is possible.
That is, when the content of the pointer H1 is the same as the instruction number of the final data block, or when the content of the pointer H1 is smaller than the instruction number of the final data block, the data insertion processing described above is executed, and the content of the pointer H1. Is larger than the instruction number of the final data block, the data insertion process may not be performed.

Next, consider a case where an accident such as a power failure occurs and the editing processing operation is interrupted before the above-described editing processing operation ends. In this case, the content of the pointer selector S is still held at “0”, and the pointer group P0 holds the state before the execution of the editing process. Therefore, there is no contradiction in the structure of the data file, and the editing process can be promptly restarted after the accident recovery. By the way, assuming that only the pointer group P0 exists and the pointer group P1 does not exist, the content of the pointer P0 is set to the pointers C1 and C.
It will be rewritten in the order of 5, C6, H1. However, in such an editing process, for example, when the process is interrupted at the time of rewriting the pointers C1 and C5, it becomes as shown in FIG. When this is read out, the data block sequence in which significant data is stored becomes B2, B3, B5, and the content of becomes (a, b, c). In addition, the blank block strings are B6 and B7, which means that logically the data blocks B0, B1, and B4 have been reduced, which causes a contradiction.

In the second case, a sequence of data blocks (a, b, c, c) in which significant data in the data file of FIG. 1 is stored.
Data (c) is deleted from (d, e, f) and data block B is deleted.
Move 5 to the back of the blank data block sequence. In this case, as shown in FIG.
In P1, this editing process may be executed, and then the pointer selector S may be changed from "0" to "1".

The data rearrangement processing is performed by pointers C0 to C7, H0, H1.
Since it can be performed only by rewriting the contents of, even if there is no blank data block in the data group DG, it can be performed without any problem.

Even in this case, it is clear that no contradiction occurs in the data file even if the editing process is interrupted as in the first case. It is also clear that if there is only one pointer group, inconsistency may occur due to interruption of processing.

In the above description, the case where there are two pointer groups has been described, but the present invention is not limited to this, and it is sufficient that there are two or more pointer groups. Further, the case where one pointer each indicating the leading block of the significant data block string and one pointer indicating the leading block of the blank data block string is provided has been described, but the present invention is not limited to this. There may be any number. When there are a plurality of these pointers, there is an advantage that it is not necessary to form a significant data block and a blank data block in one block row as shown in the above embodiment, which is convenient.

As is apparent from the above description, according to the present invention, even if an accident such as a power failure occurs during the data editing process and the processing operation is interrupted, the data at the start of the editing process that was being executed when the accident occurred Since it is saved, the editing process can be resumed immediately after the accident recovery, and the data does not become inconsistent. Moreover, this operation can be performed without a backup power supply.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a data file showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a data file showing an example when data editing processing is executed in the embodiment shown in FIG.
FIG. 3 is an explanatory diagram of a data file showing an example in which a data editing process is executed without depending on the present invention and the processing operation is interrupted, resulting in inconsistency in the data, and FIG. 4 is shown in FIG. It is explanatory drawing of the data file which shows an example at the time of performing the data edit process in the Example. DG ... Data group, P0, P1 ... Pointer group, S ...
Pointer selector, B0, B1, ..., B7 ... Data block, H
0, H1, C0, ..., C7 ... Pointers.

Claims (1)

[Claims] 1. An apparatus for executing data editing processing by connecting data in a circular list structure or a chained list structure by a pointer, and a first pointer group for storing data contents immediately before execution of the editing processing. , A second pointer group for executing the edit processing, and a first pointer group is selected while the second pointer group is executing the edit processing, and the second pointer group ends the edit processing. A data edit processing device, each of which further comprises a pointer selector for selecting the second pointer group.