JPH06332809A - Information processor - Google Patents

Abstract

PURPOSE:To prevent the malfunction of a user application using a file by storing that data are being written in a file header and judging whether or not the file is ended in the middle of write at the time of reading the tile. CONSTITUTION:At the time of writing the file 13 in an NVRAM, a flag 21 for indicating that the write to the items of the file header 14 present in the respective files 13 is in progress is provided and is set. Every time 1 byte of the data is written, the number of the written data is increased by one and is written in a data size 19 which is one item of the file header 14. Then, when the entire write operations of the data of the file 13 are completed, the data write in-progress flag 21 is cleared. When the read operation of the file 13 is requeted, the file header 14 is referred to and it is judged that the write operation is normally ended when the data write in-progress flag 21 is cleared and that the write is in the middle when the data write in-progress flag 21 is set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus, and more particularly to an information processing apparatus for writing and reading a file in an NVRAM device.

[0002]

2. Description of the Related Art In an information processing device capable of writing / reading data to / from an NVRAM device, an NVRAM
When a file is created on top of it, the file consisting of the file header and the data body is created in succession. Therefore, if the power of the system is cut off while writing the file to the NVRAM, the data of the file is partially updated, and the data is held by the backup power supply of the system. However, when such a file is read, the data of the file is read in the same way as a complete file, although the update of the data has ended halfway.

[0003]

As described above, the conventional N
In a system that writes / reads data to / from a VRAM device, if the power of the system is cut off while writing a file to / from NVRAM, the file is partially updated with data, which It is held by the system's backup power supply, so when a user's application program reads such a file, it should be used without knowing that the update of the data body has ended halfway and is incomplete. Will end up. When such a file is read by the user's application program, improper data may be handled and malfunction may occur.

Therefore, according to the present invention, when reading a file stored in an NVRAM device, the NVRA of that file is read.
An object of the present invention is to provide an information processing apparatus that can inform the user that the data of the file is incomplete for a file that has been written to M halfway.

[0005]

According to a first aspect of the present invention, there is provided an information processing device, which sequentially writes a file including a data body and a file header indicating an attribute of the data body and an address in increments of one. And an NVRAM for storing the file in successive address areas, a writing unit for writing the file in the NVRAM, and a reading unit for reading the file from the NVRAM. When writing the file into the NVRAM, the writing means stores that the data is being written in the file header, and the reading means stores the file when reading the file.
By referring to the header, it is determined whether or not the file has ended in the middle of writing.

According to a second aspect of the present invention, in the file header, the file header includes the size of the data body and a flag indicating its validity. The flag is set and written before writing the size of the data body. The reliability of the data size information is stored by clearing the flag immediately after loading.

[0007]

According to the first aspect of the present invention, when a file is written to the NVRAM device, a flag indicating that the file is being written is set in the file header, and when the writing operation of all the data in the file body is completed, Clear the writing flag. Then, when a file read operation is requested, first, the file header is referenced, and if the writing flag is cleared, this file has been written normally. If the writing flag is set, it is determined that this file is being written.

According to the present invention, when writing a file to the NVRAM device, a flag indicating that writing is in progress is set in the file header. Also, each time one byte of data is written, the number of written data is incremented by 1, and this is written in the data size item of the file header. Immediately before updating the data size item, the flag indicating that the data size is being updated is set, and after updating the data size item, the data size updating flag indicating that the data size information is valid is reset. When the writing operation of all the data in the file body is completed, the writing flag is cleared. When a file read operation is requested, first the file header is referenced, and if the write flag is cleared, this file has completed the write operation normally and is being written. If the flag is set, it is determined that this file is being written.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An information processing apparatus according to an embodiment of the present invention will be described below.

FIG. 1 is a system configuration diagram of an embodiment of an information processing apparatus of the present invention.

In FIG. 1, reference numeral 1 is a CPU (central processing unit) which controls the entire program of the system.
An external storage device 2 stores programs and the like. RO
M4 is a read-only memory in which the ROM-based program 5 is incorporated, and the RAM 6 is a random access memory in which the program 3 and the like read from the external storage device 2 are stored. The NVRAM 7 is a non-volatile memory that holds data files and the like in accordance with the instructions of the program 3 and the like, and is sequentially written so that the address increases by 1 and stores data in consecutive address areas. Reference numeral 8 is a display device for display.

FIG. 2 is a program configuration diagram in an embodiment of the information processing apparatus of the present invention.

In FIG. 2, each function is composed of an independent program. Reference numeral 9 is a manager function for controlling all functions, 10 is a program management function for calling the program 3 in the external storage device 2 onto the RAM 6, and 11 is a NVRAM write / read function for writing / reading to / from the NVRAM 7. , 12 are error message display functions on the display for displaying on the display device 8, and the error message display function 12 from the manager function 9 to the display exists in the ROM 4 as the program 5 stored in the ROM.

FIG. 3 is a schematic diagram of the structure of a file on NVRAM in one embodiment of the information processing apparatus of the present invention.

In FIG. 3, the schematic structure of the file 13 stored in the NVRAM 7 is composed of a file header 14 indicating the attributes of the file and a data body 15. The file header 14 is the name of the file 16,
The attribute 17 of the file 13, the owner name 18 of the file 13, the data size 19 of the data body 15, the creation date / time 20 of the file 13, the data writing flag 21 set when the file is being written, and the data size 19 are set. Updating flag 2 set when updating
It is composed of 2 etc.

FIG. 4 is an example of a message in one embodiment of the information processing apparatus of the present invention, FIG. 5 is a flow chart in one embodiment of the information processing apparatus of the present invention, and FIG. 6 is one of the information processing apparatus of the present invention. FIG. 7 is a flowchart showing a write request operation in the embodiment, and FIG. 7 is a flowchart showing a read request operation in the embodiment of the information processing apparatus of the present invention.

FIG. 4 shows an example of an error message displayed on the display device 8 when a file in the NVRAM 7 is being read and the file is being written.

Next, the operation of the information processing apparatus of this embodiment having the above configuration will be described.

First, in step S1, the program management function 10 of the program 5 stored in the ROM 4 of the ROM 4 loads the program 3 from the external storage device 2 onto the RAM 6. The program 3 called in step S2 is executed by the CPU 1 by the program management function for calling the program 3 in the external storage device 2 into the RAM 6. When a file write request to the NVRAM 7 is generated in the program 3, the write / read function 11 of the program 5 in the ROM 4 to / from the NVRAM 7 performs the following operation.

First, in step S11, the file header 14 in the file 13 is referred to, and in step S12, the file name 16 of the file header 14 and the attribute 17 indicating whether the file can be written or not.
And confirm with the owner name 18 of the file 13. In step S13, the date and time when the writing of the data to the file 13 is started is updated to the creation date and time 20, the writing flag 21 indicating that the data is about to be written is set, and the writing of the data is started in step S14. To do. Data writing is performed byte by byte, and the number of written data is incremented by 1 for each writing, and the data size 19 is written. At this time, the data size updating flag 22 is set before rewriting the data size 19, and immediately after writing,
Clear this flag. The writing flag 21 remains set during the data writing operation. When the writing operation of all the data of the file is completed in step S15, the in-writing flag 21 is cleared in step S16, and the data writing operation is completed.

In the program 3, NVRAM 7
When a read request for the file 13 from the
The write / read function 11 of the program 5 in the M4 to the NVRAM 7 performs the following operation.

First, in step S21, the file header 14 in the file 13 is referred to. In step S22, the name 16 of the file 13 and whether or not the file 13 can be read out are determined by the attribute 17 and the owner name 18 of the file 13. To confirm. Next, in step S23, the in-writing flag 21 of the file header 14 is referred to. If this in-writing flag 21 is cleared, it means that the writing operation of this file 13 has been completed normally. The determination can be made, and the read operation is continued as it is in step S26. Alternatively, if the writing flag 21 is set,
This file 13 stops the system while writing data,
Since this means that the writing has not been completed, the data size updating flag 22 is further referred to in step S24, and when this flag is set, step S24
25 indicates that the information itself of the data size 19 is not complete, it can be determined that the entire file cannot be compensated, and a message (see FIG. 4A) indicating that is displayed. When the data size updating flag 22 is not set, the information of the data size 19 can be determined to be reliable in step S27, and the reliable data size 19 can be determined.
Is displayed (see FIG. 4B). In this way, the reading operation of the file 13 is completed.

When the NVRAM 7 of this type is managed such that the used area and the empty area are always continuous, a change in the data size due to the rewriting of the normal file 13 causes a plurality of files arranged at the rear. Thirteen
May cause rearrangement. Even in this case,
Regarding relocated files other than original files,
The protection of the file according to the present invention is effective.

As described above, the information processing apparatus of this embodiment is
A file 13 composed of a data body 15 and a file header 14 indicating the attributes of the data body 15 is written sequentially so that the address is incremented by one, and the file 13 is written in consecutive address areas.
In an information processing apparatus, the information processing apparatus includes: an NVRAM 7 for storing a file; When writing the file 13 into the NVRAM 7, the writing means stores that the data is being written in the file header 14, and the reading means stores the file header when reading the file 13. 14, it is determined whether or not the file 13 is completed in the middle of writing.

When writing the files 13 in the NVRAM 7, a flag indicating that writing is in progress is provided in the item of the file header 14 in each file 13, and this flag is set. Each time one byte of data is written, the number of written data is incremented by 1, and this is written in the data size 19 which is one item of the file header 14. Immediately before updating the item of data size 19, a flag indicating that the data size 19 is being updated is set, and after updating the item of data size 19, to indicate the validity of the data size information,
The data size updating flag 22 is reset. When the writing operation of all the data in the file 13 is completed, the data writing flag 21 is cleared. When a read operation of the file 13 is requested, first, the file header 1
4, if the data writing flag 21 is cleared, the writing operation of the file 13 is normally completed, and the data writing flag 21 is set. For example, it is determined that this file 13 is being written. In the former case, the read operation is continued as it is,
In the latter case, this file 13 shows the number of valid data with an error message indicating that the data is incomplete. The update of the item of the data size 19 in the file header 14 does not necessarily have to be performed for each byte, and a value convenient for the system may be selected.

As a result, the user can be informed that the data of the file 13 is incomplete for the file 13 that has been written in the reading of the file 13 created in the NVRAM device.
It is possible to prevent a malfunction of a user application that uses No. 3.

By the way, in the present embodiment, the fact that data is being written is stored in the file header 14 by a flag. However, the memory occupancy of the file 13 is cleared at the start of writing, and the writing is completed. If this is done, it can be used in the same manner as the flag if it is written by adding it in update units. That is, in the case of implementing the present invention, the storage of the fact that data is being written in the file header 14 is
It does not specify the writing form of the file header 14.

[0028]

As described above, according to the information processing apparatus of the present invention, when writing a file in NVRAM, it is stored in the file header that data is being written and the file is read. At the time of output, by referring to the file header and determining whether the file has ended in the middle of writing, it is possible to easily determine whether the writing of the data of the file is completed or not.

Further, by indicating valid data of a file for which data writing has not been completed, the data of the file can be used as highly reliable data up to the middle, so that it is not necessary to invalidate the entire file. . Due to these, it is possible to prevent the malfunction of the user application that uses the file stored in the NVRAM. Further, by referring to the data size updating flag indicating the reliability of the data size information itself, it is possible to determine whether or not the data size information is reliable, and if the data size updating flag is set, it is reliable. It turns out that the size could not be stored, and the subsequent handling of the entire file can be considered. When these error states are detected, for example, the display function can give a warning to the user. This allows the user to select the remaining file data.

[Brief description of drawings]

FIG. 1 is a system configuration diagram in an embodiment of an information processing apparatus of the present invention.

FIG. 2 is a program configuration diagram in an embodiment of the information processing apparatus of the present invention.

FIG. 3 is a schematic diagram of a file structure on NVRAM in an embodiment of the information processing apparatus of the present invention.

FIG. 4 is an example of a message in an embodiment of the information processing apparatus of the present invention.

FIG. 5 is a flowchart in one embodiment of the information processing apparatus of the present invention.

FIG. 6 is a flowchart showing a write request operation in an embodiment of the information processing apparatus of the present invention.

FIG. 7 is a flowchart showing a read request operation in an embodiment of the information processing apparatus of the present invention.

[Explanation of Codes] 1 CPU 7 NVRAM 13 file 14 file header 15 data body 16 file name 17 attribute 19 data size 21 data writing flag 22 updating flag

Claims (2)

[Claims] 1. A file consisting of a data body and a file header indicating the attributes of the data body, and data is written sequentially so that the address is incremented by 1, and the file is stored in consecutive address areas. An information processing apparatus comprising: an NVRAM for writing, a writing unit for writing a file in the NVRAM, and a reading unit for reading a file from the NVRAM, wherein the writing unit writes the file in the NVRAM. The data writing is stored in the file header, and the reading means refers to the file header when reading the file, and determines whether the file is ended in the middle of writing. Information processing device. 2. The file header includes the size of the data body and a flag indicating its validity, the flag is set before writing the size of the data body, and the flag is cleared immediately after writing. Therefore, the information processing apparatus according to claim 1, wherein the reliability of the data size information is stored.