CN102521289A - File synchronization method, device and system - Google Patents

Abstract

The embodiment of the present invention discloses a file synchronization method, device and system, wherein the file synchronization method includes: synchronizing the files in the flash in the LINUX embedded system to the RAMDISK, and performing inotify registration or dnotify registration on the files in the RAMDISK ;The application of the LINUX embedded system operates on the files in the RAMDISK after the inotify registration or the dnotify registration. When the files in the RAMDISK after the inotify registration or the dnotify registration change, the files in the changed RAMDISK will be synchronized to flash. It can be seen that the application program of the embedded system only needs to read and write the files in RAMDISK, thereby improving the reading and writing speed of the embedded system and improving the response speed of the system.

Description

A file synchronization method, device and system

technical field

Embodiments of the present invention relate to the field of communication technologies, and in particular to a file synchronization method, device and system.

Background technique

At present, flash (flash memory) is usually used in embedded systems based on LINUX, such as BMC (Baseboard Management Controller, baseboard management controller). Due to the internal erasing mechanism of flash, that is, it can be rewritten after erasing, it will cause There is a second-level delay in writing files, so if you need to frequently write files on flash, there will be timeouts or slow responses.

Contents of the invention

Embodiments of the present invention provide a file synchronization method, device, and system to reduce the delay in writing files.

Embodiments of the present invention are achieved through the following technical solutions:

On the one hand, the embodiment of the present invention provides a file synchronization method, including:

Synchronize the files in the flash memory flash in the LINUX embedded system to the RAM disk RAMDISK, and carry out inotify registration or dnotify registration to the files in the RAMDISK;

The application program of the LINUX embedded system operates on the files in the RAMDISK after the inotify registration or the dnotify registration, when the files in the RAMDISK after the inotify registration or the dnotify registration change, Synchronize the changed files in the RAMDISK to the flash.

On the other hand, an embodiment of the present invention provides a file synchronization device, including:

The first synchronization unit is used to synchronize the files in the flash memory flash in the LINUX embedded system to the RAM disk RAMDISK;

A registration unit, configured to perform inotify registration or dnotify registration on files in the RAMDISK;

The second synchronization unit is used for the application program of the LINUX embedded system to operate the files in the RAMDISK after the inotify registration or the dnotify registration, when the inotify registration or the dnotify registration The RAMDISK When the files in the RAMDISK change, the changed files in the RAMDISK are synchronized to the flash.

On the other hand, an embodiment of the present invention provides a file synchronization system, including a synchronization unit, a flash, and a RAMDISK, the synchronization unit is used to synchronize files in the flash to the RAMDISK, and inotify the files in the RAMDISK Registration or dnotify registration; the application program of the LINUX embedded system operates the files in the RAMDISK after the inotify registration or the dnotify registration, when the inotify registration or the dnotify registration in the RAMDISK When a file changes, the changed file in the RAMDISK is synchronized to the flash.

As can be seen from the technical scheme provided by the present invention above, the LINUX embedded system uses the inotify or dnotify file notification mechanism to map the files in the RAMDISK and the files in the flash, and the application program of the embedded system only needs to read and write the files in the RAMDISK. files, thereby improving the read and write speed of the embedded system and improving the response speed of the system.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative work.

FIG. 1 is a schematic flowchart of a file synchronization method provided by an embodiment of the present invention.

FIG. 2 is a schematic diagram of the structure of a file synchronization device provided by an embodiment of the present invention.

FIG. 3 is a first schematic diagram of the application flow of the file synchronization method provided by the embodiment of the present invention.

FIG. 4 is a second schematic diagram of the application flow of the file synchronization method provided by the embodiment of the present invention.

FIG. 5 is a third schematic diagram of the application process of the file synchronization method provided by the embodiment of the present invention.

FIG. 6 is a fourth schematic diagram of the application flow of the file synchronization method provided by the embodiment of the present invention.

FIG. 7 is a fifth schematic diagram of the application flow of the file synchronization method provided by the embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1, the embodiment of the present invention provides a kind of file synchronization method, can be applied in the embedded system based on LINUX, and method comprises:

11. Synchronize the files in the flash memory in the LINUX embedded system to the RAM disk RAMDISK, and perform inotify registration or dnotify registration on the files in the RAMDISK.

12. The application program of the LINUX embedded system operates the files in the RAMDISK after the inotify registration or the dnotify registration, when the files in the RAMDISK after the inotify registration or the dnotify registration change When, the changed files in the RAMDISK are synchronized to the flash.

The file synchronization method of the embodiment of the present invention, under the situation that does not change the read-write file mode of the application program of LINUX embedded system, uses LINUX kernel inotify or dnotify file notification mechanism, the file in RAMDISK and the file in flash are mapped, The application program of the embedded system only needs to read and write the files in RAMDISK, thus improving the reading and writing speed of the embedded system and improving the response speed of the system.

Optionally, in the above step 12, the application program of the LINUX embedded system operates on the files in the RAMDISK after the inotify registration or the dnotify registration, which may include: after the inotify registration or the dnotify registration After the file is read, or written, or moved, or deleted, and so on.

Optionally, in step 12 above, the change of the file after the inotify registration or the dnotify registration may include: the file after the inotify registration or the dnotify registration is modified, or moved, or deleted, etc.

Optionally, the file synchronization method in the embodiment of the present invention may also include:

According to the modified frequency characteristics and file usage of the files, the files in the flash are divided into log type files and configuration type files, and the frequency of modification of the log type files is greater than the modification frequency of the configuration type files , the log type file is used to record logs, and the configuration type file is used to set the environment required for application loading.

Log type files are used to record logs, and are usually operated frequently, and log type files are only modified by appending content. The configuration type file is used to set the environment required for application loading. Although the configuration type file will be modified, the operation frequency is usually small.

Furthermore, for log type files, since they are usually not modified, there is no need to perform backup in the flash. As for the configuration type files, since they are usually modified and added, the files in the flash need to be backed up to obtain corresponding main files and backup files.

Optionally, in the file synchronization method of the embodiment of the present invention, it may be determined by reading the configuration file that the file in the flash belongs to a log type file or a configuration type file.

The following describes the file synchronization method of the embodiment of the present invention for log type files and configuration type files:

For log type files, the files in flash are synchronized to RAMDISK, which can include:

Directly copy log type files in flash to RAMDISK.

Further, for log type files, synchronizing the changed files in RAMDISK to flash may include:

Use the method of incremental synchronization to synchronize the log type files in RAMDISK to flash. Based on the fact that each record in the log type file has a fixed length, or ends with a newline character, you can synchronize the added records in the file to the flash instead of synchronizing the entire file to the flash.

Optionally, for a log type file, after starting (including initial startup and restart) the LINUX embedded system, according to the characteristics of the log type file (each record has a fixed length, or ends with a newline character), the The integrity of the log type file in the flash is checked. If the last record of the log type file is incomplete, the last record can be deleted.

For configuration type files, the files in flash are synchronized to RAMDISK, which can include:

According to the CRC (Cyclic Redundancy Check, Cyclic Redundancy Check) value or MD5 (Message-Digest Algorithm 5, information-digest algorithm 5) value of the main file in the flash to judge the legality of the main file, when the main file is legal , synchronizing the main file into RAMDISK and synchronizing into the backup file;

When the main file is illegal, judge the validity of the backup file in the flash according to the CRC value or the MD5 value of the backup file in the flash, and when the backup file is legal, synchronize the backup file into RAMDISK and synchronize into the main file.

Wherein, the CRC value or MD5 value may include: an initial CRC value or MD5 value, or an updated CRC value or MD5 value.

Wherein, it is not limited to the CRC algorithm or MD5, and any algorithm that can realize the legality of the file can be applied.

Further, for configuration type files, synchronizing the changed files in RAMDISK to flash may include:

According to the CRC algorithm or MD5, calculate the updated CRC value or MD5 value of the file in the changed RAMDISK;

First synchronizing the updated CRC value or MD5 value to the main file in the flash, and then synchronizing the changed file in the RAMDISK to the corresponding main file in the flash;

Synchronize the updated CRC value or MD5 value to the backup file in the flash, and then synchronize the changed file in the RAMDISK to the corresponding backup file in the flash.

Optionally, the file synchronization method in the embodiment of the present invention may use a hardware encryption engine to calculate the CRC value or MD5 value of the file, reducing CPU overhead. Exemplary, such as the C3 hardware encryption engine, when calculating the CRC value or MD5 value of the file, the API (Application Programming Interface, Application Programming Interface) of the C3 hardware encryption engine can be called to calculate, thereby reducing CPU (Central Processing Unit, CPU) overhead.

As shown in Figure 2, corresponding to the file synchronization method of the above-mentioned embodiment, the embodiment of the present invention provides a file synchronization device 20, which can be a small computer, or a personal computer, a network node, etc., including:

The first synchronization unit 21 is used for synchronizing the files in the flash memory in the LINUX embedded system to the random storage memory disk RAMDISK.

The registration unit 22 is configured to perform inotify registration or dnotify registration on the files in the RAMDISK.

The second synchronization unit 23 is used for the application program of the LINUX embedded system to operate the files in the RAMDISK after the inotify registration or the dnotify registration, when the inotify registration or the dnotify registration When the files in the RAMDISK change, the changed files in the RAMDISK are synchronized to the flash.

The file synchronizing device of the embodiment of the present invention, under the situation that does not change the read-write file mode of the application program of LINUX embedded system, uses LINUX kernel inotify or dnotify file notification mechanism, the file in RAMDISK and the file in flash are mapped together, The application program of the embedded system only needs to read and write the files in RAMDISK, thus improving the reading and writing speed of the embedded system and improving the response speed of the system.

Optionally, the first synchronization unit 21 and the second synchronization unit 23 may be implemented by one synchronization unit without limitation.

Optionally, the second synchronization unit 23 can specifically be used to read, write, move, or delete files after the inotify registration or the dnotify registration. After the inotify registration or When the file registered with dnotify is modified, moved, or deleted, the changed file in the RAMDISK is synchronized to the flash.

The file synchronization device of the embodiment of the present invention may also include:

The division unit is used to divide the files in the flash into log type files and configuration type files according to the frequency characteristics and file usages of the files being modified, and the frequency of modification of the log type files is greater than that of the configuration type files Modified frequency, the log type file is used to record logs, and the configuration type file is used to set the environment required for application loading. as well as,

The backup unit is configured to back up the files in the flash for the configuration type files to obtain corresponding main files and backup files.

Optionally, for configuration type files, the first synchronization unit 21 can specifically be used for:

Judging the legality of the main file according to the CRC value or the MD5 value of the main file in the flash, when the main file is legal, synchronizing the main file into RAMDISK and synchronizing into the backup file;

When the main file is illegal, judge the validity of the backup file in the flash according to the CRC value or the MD5 value of the backup file in the flash, and when the backup file is legal, synchronize the backup file into RAMDISK and synchronize into the main file.

Wherein, the CRC value or the MD5 value may include: initially setting the CRC value or the MD5 value, or updating the CRC value or the MD5 value.

Further, optionally, for configuration type files, the second synchronization unit 23 may specifically be used for:

According to the CRC algorithm or MD5, calculate the updated CRC value or MD5 value of the file in the changed RAMDISK;

First synchronizing the updated CRC value or MD5 value to the main file in the flash, and then synchronizing the changed file in the RAMDISK to the corresponding main file in the flash;

Synchronize the updated CRC value or MD5 value to the backup file in the flash, and then synchronize the changed file in the RAMDISK to the corresponding backup file in the flash.

The file synchronization device and its configuration in the embodiment of the present invention can be understood by correspondingly referring to the relevant content of the file synchronization method in the above embodiment, and details are not described here.

The embodiment of the present invention provides a file synchronization system, including a synchronization unit, flash and RAMDISK, the synchronization unit is used to synchronize the files in the flash to the RAMDISK, and perform inotify registration or dnotify registration on the files in the RAMDISK ; The application program of the LINUX embedded system operates the files in the RAMDISK after the inotify registration or the dnotify registration, when the files in the RAMDISK after the inotify registration or the dnotify registration change , synchronizing the changed files in the RAMDISK to the flash.

The file synchronous system of the embodiment of the present invention, under the situation that does not change the read-write file mode of the application program of LINUX embedded system, uses LINUX kernel inotify or dnotify file notification mechanism, the file in RAMDISK and the file in flash are mapped together, The application program of the embedded system only needs to read and write the files in RAMDISK, thus improving the reading and writing speed of the embedded system and improving the response speed of the system.

The embodiment of the present invention provides a file synchronization method. In order to improve the response speed and user experience of the embedded system, without changing the way of reading and writing files of the application program of the embedded system, a synchronization unit is added, and the LINUX kernel is used. The inotify or dnotify file notification mechanism maps the files in RAMDISK and the files in flash, and the application program of the embedded system only needs to read and write the files in RAMDISK, thereby improving the read and write speed of the embedded system and improving the system performance. responding speed.

As shown in Figure 3, the file synchronization method of the embodiment of the present invention includes:

31. Start the LINUX embedded system.

Start the LINUX embedded system, because the synchronization unit must synchronize the files in the flash to the RAMDISK before other processes start. Therefore, process locks can be used to prevent other processes from starting without reading the files in RAMDISK, causing unpredictable errors. The process locks cannot be released until the synchronization unit synchronizes the files in flash to RAMDISK, allowing other processes start up.

32. Synchronize files in flash to RAMDISK.

The synchronization unit determines the type of the file by reading the configuration file, and then determines which files in the flash are to be synchronized into the RAMDISK.

Exemplarily, "LOG" in the ProtectType field of the configuration file indicates "log type", and "CONF" indicates "configuration type".

Exemplary, Table 1:

As shown in Figure 4, for the log type, the files in the flash are synchronized to the RAMDISK, specifically: the corresponding files in the flash are directly synchronized to the RAMDISK.

As shown in Figure 5, for the configuration type, synchronize the files in flash to RAMDISK, specifically:

51. Determine the legality of the master file.

For example, the validity of the master file is judged by CRC algorithm or MD5, if the master file is legal, go to 52, if the master file is not legal, go to 53.

52. If the master file is valid, synchronize the master file to RAMDISK and update the backup file at the same time.

For example, synchronize the master file to RAMDISK, update the backup file at the same time, and update the CRC value or MD5 value of the backup file.

53. If the master file is illegal, judge the validity of the backup file.

For example, the validity of the backup file is judged by the CRC algorithm or MD5. If the backup file is legal, enter 54. If the backup file is invalid, enter exception processing.

54. If the backup file is valid, synchronize the backup file to RAMDISK and update the master file at the same time.

For example, synchronize the backup file to RAMDISK, update the master file at the same time, and update the CRC value or MD5 value of the master file.

After that, after synchronizing the files in flash to RAMDISK, you need to release the process lock to allow other processes to start.

33. Inotify or dnotify registers files in RAMDISK.

Call the API (Application Programming Interface, application programming interface) of LINUX kernel inotify or dnotify, and perform Inotify or dnotify to register the file in RAMDISK.

Inotify or dnotify registers the files in the RAMDISK, which can be understood by referring to the prior art, and will not be described in detail here.

34. Receive a notification from the LINUX kernel inotify or dnotify that the file in RAMDISK has changed.

Use the API of LINUX kernel inotify or dnotify to determine that the files in RAMDISK have changed.

Receive the Linux kernel inotify or dnotify notice that the files in the RAMDISK have changed, which can be understood by referring to the existing technology, and will not be repeated here.

35. Synchronize the changed files in RAMDISK to flash.

As shown in Figure 6, for the log type, use incremental synchronization to synchronize files in RAMDISK to flash.

As shown in Figure 7, for the configuration type, synchronize the files in RAMDISK to flash, including:

71. Calculate the updated CRC value or MD5 value of the file in RAMDISK through CRC algorithm or MD5.

72. First synchronize the updated CRC value or MD5 value to the main file in the flash, and then synchronize the file in RAMDISK to the corresponding main file in the flash.

73. Synchronize the updated CRC value or MD5 value to the backup file in flash, and then synchronize the file in RAMDISK to the corresponding backup file in flash.

The following takes umconfig.tx in the flash of the LINUX embedded system as an example to briefly explain the file synchronization of the configuration type:

When the LINUX embedded system is initially powered on and started, the MD5 values of the master file and the backup file in umconfig.txt in the flash are both 11223344, and the master file is legal. Synchronize the master file to RAMDISK.

When umconfig.txt in RAMDISK is modified, calculate the MD5 value of umconfig.txt in RAMDISK, for example, the MD5 value is 55667788. Update the MD5 value of the master file of umconfig.txt in the flash to 55667788, and update the umconfig.txt in RAMDISK to the master file of umconfig.txt in the flash. Update the MD5 value of the umconfig.txt backup file in the flash to 55667788, and update the umconfig.txt in the RAMDISK to the umconfig.txt backup file in the flash. At this time, the MD5 values of the master file and the backup file of umconfig.txt in the flash are both 55667788.

If the LINUX embedded system suddenly loses power during the process of updating umconfig.txt in RAMDISK to the master file of umconfig.txt in flash, the MD5 value of the master file in umconfig.txt in flash will be 55667788, but the umconfig in flash The content of the .txt master file is incomplete, but the content of the umconfig.txt backup file in the flash is complete, and the MD5 value of the backup file is still 11223344.

Then, when the LINUX embedded system is powered on again, the master file of umconfig.txt in the flash is judged to be illegal according to the MD5 value of 55667788, and the backup file of umconfig.txt in the flash is judged to be legal according to the MD5 value of 11223344. The backup file of umconfig.txt is synchronized to RAMDISK, and the backup file of umconfig.txt in flash is synchronized to the master file of umconfig.txt in flash.

Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented through computer programs to instruct related hardware, and the programs can be stored in a computer-readable storage medium. During execution, it may include the processes of the embodiments of the above-mentioned methods. Wherein, the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM) or a random access memory (Random Access Memory, RAMDISK), etc.

Claims (11)

1. A file synchronization method, characterized in that, comprising: Synchronize the files in the flash memory flash in the LINUX embedded system to the RAM disk RAMDISK, and carry out inotify registration or dnotify registration to the files in the RAMDISK; The application program of the LINUX embedded system operates on the files in the RAMDISK after the inotify registration or the dnotify registration, when the files in the RAMDISK after the inotify registration or the dnotify registration change, Synchronize the changed files in the RAMDISK to the flash. 2. method according to claim 1, is characterized in that, the application program of described LINUX embedded system operates to the file in RAMDISK after described inotify registration or described dnotify registration, comprising: Perform a read operation, or write operation, or move operation, or delete operation on the file after the inotify registration or the dnotify registration; The file changes after the inotify registration or after the dnotify registration, including: The file after the inotify registration or the dnotify registration is modified, or moved, or deleted. 3. The method according to claim 1 or 2, characterized in that the method further comprises: The files in the flash are divided into log type files and configuration type files, the modified frequency of the log type files is greater than the modified frequency of the configuration type files, and the log type files are used for recording logs, so The configuration type file described above is used to set the environment required for application loading; For the configuration type file, the files in the flash are backed up to obtain the corresponding main file and backup file. 4. The method according to claim 3, wherein, for the configuration type file, synchronizing the file in the flash to the RAMDISK includes: Judge the validity of the master file in the flash according to the cyclic redundancy check CRC value or the information-digest algorithm MD5 value of the master file in the flash, and when the master file is legal, synchronize the master file into RAMDISK and synchronized to the backup file; When the main file is illegal, judge the validity of the backup file in the flash according to the CRC value or the MD5 value of the backup file in the flash, and when the backup file is legal, synchronize the backup file into the RAMDISK and synced into said master file; Wherein, the CRC value or MD5 value includes an initial CRC value or MD5 value, or an updated CRC value or MD5 value. 5. The method according to claim 4, wherein, for the configuration type file, synchronizing the changed file in the RAMDISK to the flash includes: According to the CRC algorithm or MD5, calculate the updated CRC value or MD5 value of the file in the RAMDISK that changes; First synchronizing the updated CRC value or MD5 value to the main file in the flash, and then synchronizing the changed file in the RAMDISK to the corresponding main file in the flash; Synchronize the updated CRC value or MD5 value to the backup file in the flash, and then synchronize the changed file in the RAMDISK to the corresponding backup file in the flash. 6. A file synchronization device, characterized in that it comprises: The first synchronization unit is used to synchronize the files in the flash memory flash in the LINUX embedded system to the RAM disk RAMDISK; A registration unit, configured to perform inotify registration or dnotify registration on files in the RAMDISK; The second synchronization unit is used for the application program of the LINUX embedded system to operate the files in the RAMDISK after the inotify registration or the dnotify registration, when the inotify registration or the dnotify registration The RAMDISK When the files in the RAMDISK change, the changed files in the RAMDISK are synchronized to the flash. 7. The device according to claim 6, wherein the second synchronizing unit is specifically configured to perform a read operation, a write operation, or a move operation on the file after the inotify registration or the dnotify registration , or a delete operation, when the file after the inotify registration or the dnotify registration is modified, moved, or deleted, the changed file in the RAMDISK is synchronized to the flash. 8. The device according to claim 6 or 7, wherein the device further comprises: A division unit, configured to divide the files in the flash into log type files and configuration type files, the frequency of modification of the log type files is greater than the frequency of modification of the configuration type files, and the log type files use For recording logs, the configuration type file is used to set the environment required for application loading; The backup unit is configured to back up the files in the flash for the configuration type files to obtain corresponding main files and backup files. 9. The device according to claim 8, wherein, for the configuration type file, the second synchronization unit is specifically configured to: Judge the validity of the master file in the flash according to the cyclic redundancy check CRC value or the information-digest algorithm MD5 value of the master file in the flash, and when the master file is legal, synchronize the master file into RAMDISK and synchronized to the backup file; When the main file is illegal, judge the validity of the backup file in the flash according to the CRC value or the MD5 value of the backup file in the flash, and when the backup file is legal, synchronize the backup file to RAMDISK and synchronized to said master file; Wherein, the CRC value or MD5 value includes an initial CRC value or MD5 value, or an updated CRC value or MD5 value. 10. The device according to claim 9, wherein, for the configuration type file, the first synchronization unit is specifically configured to: According to the CRC algorithm or MD5, calculate the updated CRC value or MD5 value of the file in the RAMDISK that changes; First synchronizing the updated CRC value or MD5 value to the main file in the flash, and then synchronizing the changed file in the RAMDISK to the corresponding main file in the flash; Synchronize the updated CRC value or MD5 value to the backup file in the flash, and then synchronize the changed file in the RAMDISK to the corresponding backup file in the flash. 11. A file synchronization system, characterized in that it includes a synchronization unit, flash and RAMDISK, the synchronization unit is used to synchronize the files in the flash to RAMDISK, and carry out inotify registration or dnotify to the files in the RAMDISK Registration; the application program of the LINUX embedded system operates the files in the RAMDISK after the inotify registration or the dnotify registration, when the files in the RAMDISK after the inotify registration or the dnotify registration change When, the changed files in the RAMDISK are synchronized to the flash.

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