JPS62192826A - File writing system - Google Patents

Abstract

PURPOSE:To execute a re-trial without leaving an ineffective file, by recording a position in an ended file medium, when a series of write processings have been ended, discriminating an effective file at the time starting the next processing, based on said recording and writing anew file from immediately after said discrimination. CONSTITUTION:When a file A has been recorded normally to a position X in a file medium 7, its position X is recorded as a file end position together with a file name A in a recording means 4. Subsequently, when a write instruction of other file B is given from a user program 5, a control means 1 makes a file end position recognizing means 2 read the position X of the means 4, and when an end-of-file has been recorded in the position X of the medium 7, the first block B1 of the file B is written immediately after the file A, and subsequently, blocks B2... are written and the file B is recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a file writing method.

There are two file writing methods: one is to write file information directly to the final file medium location, and the other is to write file information to an irregular area and copy it to the final file media location when writing is completed normally. However, since the former method is more advantageous in terms of cost and processing speed, it is generally used more often than the latter.

The VTOC file writing method, which is a type of the former file writing method, writes a new file B when file A has already been written normally on a file medium such as a magnetic disk, as shown in Section 4tiJ (A). Writing is performed in extended mode starting from the end of file (EOF) recorded at the end of file A, as shown in FIG. 3B, and the EOF is recorded at the end of file B. Further, FIG. 3(C) shows a state when the write process for file B is terminated midway for some reason, and in such a case, an EOF is written at the position where the write process ended midway.

[Conventional technology]

By the way, as mentioned above, for some reason, file B
If the process ends midway, that part of file B becomes invalid, and it is necessary to write file B again by retrying or the like. In this case, since it was not possible to know which part of the file was valid using the conventional file writing method, one of the following methods was conventionally employed in this case.

■ A method of erasing the entire file medium and rewriting from the first file A ■ A method of leaving the already written part of the file B as an invalid file and writing again from the beginning of the file B in the area after EOF [The invention aims to solve this problem] [Problems] However, with method (■) above, there is a waste of retrying the valid file part (file A).
Furthermore, since the retry is performed from the beginning of the file medium, the processing time becomes longer, and there is also the disadvantage that the probability that the process will be terminated midway again increases accordingly. Furthermore, the conventional method (2) has the drawback that the written portion of file B remains as an invalid file, reducing the efficiency of file medium usage.

The present invention has solved these conventional problems, and its purpose is to provide a file writing method that does not leave invalid files (and can perform retries at high speed).

[Means for solving problems]

In order to achieve the above object, the present invention records an EOF at the position in the file medium where writing is completed even if a series of file writing processes to the file medium are terminated midway due to some reason other than normal termination. In the file writing method, the file end position recording means records the ending position in the file medium when a series of writing processes are normally completed; a file end position recognition means for determining from the file end position recorded in the recording means how far out of the file in the file is a valid file; It consists of a file write control means for writing a new file immediately after the file.

[Effect]

When a series of writing processes is completed normally, the position in the file medium at which it ended is recorded in the recording means, so even if it ends midway for some reason, the recording means will still have the valid last position of the file. is stored, and the file write control means writes a new file immediately after that, so no invalid file remains, and even in the case of retrying, the file is stored in the middle of the file medium, i.e., a valid file. You can start writing immediately after.

〔Example〕

FIG. 1 is a block diagram of an embodiment of the present invention, in which 1 is a file write control means, 2 is a file end position recognition means, 3 is a file end position recording means, 4 is a recording means, 5 is a user program, 6 is a file management program, 7 is a file medium such as a magnetic disk, and 10 is a processing device. Further, FIG. 2 is a flowchart showing an example of the processing performed by the file write control means 1.

Now, assuming that the file A is normally recorded on the file medium 7 up to the position X as shown in FIG. x is recorded, and A is recorded as the file name.

If the user program 5 instructs to write another file B in this state, the file write control means 1 first confirms the end position of the file, as shown in FIG. 2 (Sl). This is done by activating the file end position recognizing means 2 to read the file end position X of the recording means 4 and receiving it.

After confirming the file end position X, the file write control means 1 then determines whether EOF is recorded at the file end position X of the file medium 7 (B2).
. In this case, it is assumed that writing to file A has been completed normally, so EOF is recorded at the file end position Input the first block of information (hereinafter referred to as block) B1 of B (B3) and write it after the EOF position, that is, immediately after writing to the file (B5), as shown in Figure 3 (B). Block read and write operations are performed under the control of the file management program. When the writing of one block is completed, the file writing control means 1 writes the next block B2 of the file B, the writing of the block B3, etc.
Write in the same manner as above, and write in Figure 3 (C
), when the writing of the last block Bn is completed (S7), the EOF is recorded immediately after that (B8), and the last position Z of the file B is recorded in the recording means 4 as the file end position and as the file name. Record B (
B9). The file end position and file name are recorded by activating the file end position recording means 3.

The above is a case where the writing of the file information book has completed successfully to the end, but when it is detected that an error has occurred in the manual input of the file information from the input side or in the writing of the file during the writing of the file (B4 .B6), as shown in Figure 3 (D), record EOF after the block Bi that has already been written up to the time of error occurrence, finish the file write process, and perform error processing such as sending one message. Do it (519).

Now, since writing of file name B has ended midway,
When the user program 5 etc. instructs to write the file B again, the file write control means 1 restarts the process shown in FIG. 2. In this case, since the file end position recorded in the recording means 4 remains at X, the determination in step S2 is No, and the process in step 310 is performed unlike when the process ends normally. That is,
First, the file write control means 1 sets the file write mode to the update mode (310). This is because in the VTOC file write control, the EOF
This is based on the fact that writing new file information to the previous area can only be executed in update mode.

When the file write control means 1 is set to update mode,
Next, input the first block Bl' of file B from the input side (511), and write it at the file end position recorded in the recording means 4, that is, the position X, as shown in FIG. 3(E). S13).

Then, step S12. If no error occurs in the block input and writing in S14, it is confirmed that the file B has not ended (318), and the next block B2° and subsequent blocks are written in the same manner.

As shown in FIG. 3(E), block writing is performed up to block Bi'', and the next block B (-1 is written, then writing is performed in the update mode to the area after EOF. Therefore, step S14
An error occurs. When the file write control means 1 determines that this error is an error caused by EOF detection (S15), it switches the access mode from the update mode to the expansion mode (S16), and writes Y as shown in FIG. 3(F). After rewriting block B 441' to the position (S17), the remaining blocks up to block Bn' are written in the same expanded mode. And file B
When the writing is completed, immediately after that, as shown in FIG. Record (B9).

The above is a process for writing file B again by retrying, but the same process is performed when writing another file C in the state shown in FIG. 3(D).

As described above, according to this embodiment, it is possible to write the next file without leaving an invalid file, and retry can be performed immediately after the valid file. In addition, the file write control means 1 automatically switches the file access method between the update mode and expansion mode in the X-Y area and Y-Z area on the file medium 7, that is, the area before and after the EOF. Since the program appears to be a simple write process starting from position X, it can be implemented without changing the user program.

〔Effect of the invention〕

As explained above, the present invention records the position of the file medium where a series of write processes have successfully completed, and writes file information while always checking the write end position when starting the write process. In the next write process when the write process ends midway, no invalid area is left in the file medium, and in the retry process for the mid-way end of the write process, it is possible to retry from the middle of the file medium. Efficient writing to the medium can be achieved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a flowchart showing an example of processing by the file write control means 1, FIG. 3 is an explanatory diagram of the operation of the embodiment of the present invention, and FIG. 4 is a conventional FIG. 2 is an explanatory diagram of a file writing method. 1 is the file write control means, 2 is the file end position P
! 3 is a file end position recording means, 4 is a recording means, 5 is a user program, 6 is a file management program, 7 is a file medium, and 10 is a processing device.

Claims (1)

[Claims] Even if a series of file writing processes to a file medium are terminated midway due to some reason other than normal termination, the end of file is recorded at the position in the file medium at which writing is completed. In the file writing method, there is provided a file end position recording means for recording in a recording means the position in the file medium at which a series of writing processes has ended normally; file end position recognition means for determining from the file end position recorded in the recording means how far out of the existing file is a valid file; and a file end position recognition means determined by the file end position recognition means at the time of writing processing. A file writing method characterized by comprising a file writing control means for writing a new file immediately after.