CN106909398A - The compression method and device of a kind of executable file - Google Patents

Abstract

The embodiment of the invention discloses a compression method and device for an executable file. The method includes: analyzing the functional attributes and storage format attributes of each part of the executable file data; identifying the compressible target data in each part of the data according to the functional attributes; according to the storage format of the target data attribute, to obtain a compression strategy for the target data; according to the compression strategy, compress the target data, and update the storage format attribute of the target data, to obtain a compressed executable file. By adopting the above technical solution, the compressed executable file can occupy less storage space, achieve the effect of saving hardware cost, and enhance the market competitiveness.

Description

Compression method and device for an executable file

technical field

The embodiment of the present invention relates to the field of embedded technologies, and in particular to a method and device for compressing executable files.

Background technique

With the continuous development of science and technology, the competition in industries such as television is becoming more and more fierce. Among them, cost competition is a very important aspect, and how to reduce costs is also a problem that most companies need to consider.

Taking the TV manufacturing industry as an example, cost competition mainly focuses on hardware. In terms of software, the material cost of the TV storage hardware is generally reduced by reducing the size of the executable file, thereby reducing the size of the storage chip space.

In the prior art, generally, different compression algorithms are determined according to different executable files to compress the executable files. However, when there are many executable files and each executable file is compressed separately, there may be a situation where the storage space cannot store all the compressed executable files. This is because, during the compression and/or decompression process of each executable file, it is necessary to open up additional storage space for the execution of the compression and/or decompression algorithm, and when there are many executable files, it is necessary to perform compression and/or decompression The compression algorithm itself requires a lot of additional storage space. When the storage space cannot meet the requirements of the compression and/or decompression algorithm, the effect of the compression and/or decompression algorithm will be affected, which will cause the storage device occupied by the file The increased space increases the cost of the memory chip for storing executable files.

Therefore, the compression method and compression efficiency of executable files in the prior art need to be improved.

Contents of the invention

In order to solve the above related technical problems, the present invention provides a method and device for compressing executable files to improve the compression rate of executable files, save the storage space of storage chips for storing executable files, and indirectly achieve the technical effect of saving hardware costs.

In order to achieve the above purpose, the embodiment of the present invention adopts the following technical solutions:

In a first aspect, an embodiment of the present invention provides a method for compressing an executable file, the method comprising:

Analyzing the functional attributes and storage format attributes of the data in each part of the executable file;

Identifying compressible target data in each part of data according to the functional attributes;

Obtaining the compression policy of the target data according to the storage format attribute of the target data;

According to the compression strategy, the target data is compressed, and the storage format attribute of the target data is updated to obtain a compressed executable file.

In a second aspect, an embodiment of the present invention provides an executable file device, the device comprising:

An attribute analysis module, configured to analyze the functional attributes and storage format attributes of the data of each part of the executable file;

A target data identification module, configured to identify compressible target data in each part of the data according to the functional attributes;

A compression strategy determination module, configured to obtain a compression strategy for the target data according to the storage format attribute of the target data;

The compression module is configured to compress the target data according to the compression strategy, and update the storage format attribute of the target data to obtain a compressed executable file.

The embodiment of the present invention provides a method and device for compressing an executable file. Firstly, the functional attributes and storage format attributes of each part of the executable file are analyzed, and according to the functional attributes of each part of the data, it is possible to identify the The target data; according to the storage format attribute of the target data, the compression strategy of the target data can be obtained; according to the compression strategy, the compressible target data is compressed, and the storage format attribute of the target data is updated to obtain the compressed executable file. By adopting the above technical solution, compared with the prior art, the compressed executable file can occupy less storage space, achieve the technical effect of saving hardware cost for storing the executable file, and indirectly improve the market competitiveness of the product.

Description of drawings

In order to more clearly illustrate the technical solutions in 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 of the present invention. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention , for those skilled in the art, other drawings can also be obtained according to the content of the embodiment of the present invention and these drawings without any creative effort.

FIG. 1 is a flow chart of a method for compressing an executable file provided in Embodiment 1 of the present invention;

Figure 2a is a kind of executable binary file data generated after writing the FLASH operation;

Figure 2b is another executable binary file data generated after the FLASH operation;

Figure 3a is a distribution diagram of the data storage structure of the TV FLASH memory before optimization provided by Embodiment 1 of the present invention;

Figure 3b is a distribution diagram of the data storage structure of the optimized TV FLASH memory provided by Embodiment 1 of the present invention;

FIG. 4 is a flow chart of an executable file compression method provided in Embodiment 2 of the present invention;

FIG. 5 is a schematic diagram of a comparison of storage space occupied by an executable file before and after compression provided in Embodiment 2 of the present invention;

FIG. 6 is a structural block diagram of an executable file compression device provided by Embodiment 3 of the present invention.

detailed description

In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only the technical solutions of the present invention. Some, but not all, embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

Embodiment one

FIG. 1 is a flow chart of a method for compressing an executable file provided by Embodiment 1 of the present invention. The method of this embodiment may be executed by a device for compressing executable files such as a TV and/or a TV set-top box, wherein the method may be implemented by software and/or hardware deployed in a TV and/or a TV set-top box, the software And/or hardware can generally be integrated in an embedded system. As shown in Figure 1, the method may include the following steps:

S110: Analyze the functional attributes and storage format attributes of the data in each part of the executable file.

Wherein, an executable file refers to a file loaded and executed by an operating system, and the executable file mentioned in this embodiment is preferably an executable binary (bin) file. The above-mentioned executable binary file may be a compressed binary file or a non-compressed binary file. Wherein, those skilled in the art can judge whether the binary file has been compressed according to the compression identifier carried in the executable binary file.

Exemplarily, the storage format attribute of each part of the data in the executable file can be obtained from the identifier that identifies the corresponding storage format of the part of the data attached to the corresponding storage path of each part of the data, usually including the following three situations:

1. There is no compression mark added to the corresponding storage path;

For an executable file without any compression mark added to the corresponding storage path of each part of data, the compiler only needs to complete normal compilation processing when compiling the file, without any compression and decompression processing.

2. A compression flag with a lower compression ratio is added to the corresponding storage path;

Preferably, the preset storage format attribute in the embodiment of the present invention refers to, in the storage path, according to the first preset storage format (such as the identifier "-g") or the second preset storage format (such as the identifier "-g") 7") The characteristic attribute that the saved executable file has. The compression ratios corresponding to the above two storage formats are different, the compression ratio corresponding to the first preset storage format is relatively low, and the compression ratio corresponding to the second preset storage format is relatively high. Specifically, when the flag of the first preset storage format is "-g". If the presence of the "-g" identifier is detected in the corresponding storage path of a certain part of the data in the executable binary file, it means that the compiler will The compression process is performed with a smaller compression rate to save the storage space occupied by the binary file, thereby saving the material cost of hardware (such as a memory chip) for storing the binary file.

3. A compression mark with a higher compression rate is added to the corresponding storage path.

Preferably, when the identifier of the second preset storage format is "-7". If the "-7" identifier is detected in the corresponding storage path of a certain part of the data in the executable binary file, it means that the compiler presses the larger Compared with the first preset storage format whose identifier is "-g", the above compression method can further save the storage space occupied by the executable binary file, so as to save the storage space of the binary file. The material cost of the file hardware.

It should be noted that due to numerous compression algorithms and technologies, the storage format of the data of each part of the executable binary file is not limited to the three forms listed above.

S120: Identify compressible target data in each part of data according to the functional attributes.

Further, before each part of the executable binary file is compressed, it is necessary to judge whether each part of the data in the executable binary file can be compressed according to the basic characteristic of the functional attribute of each part of data. Exemplarily, the functional attributes of each part of data in the executable binary file may include, but not limited to, storage attributes, compression or decompression attributes, and the like. In the specific operation process, for the data of an executable binary file with decompression attribute or tag attribute, it cannot be compressed against its data attribute; and for the data in a binary file with storage attribute, then It can be compressed to save storage space.

Exemplarily, the actual structure of the system is used as an example below to illustrate, and the system is preferably a NOS (No Operating System, no operating system) system:

00113: #define IMG_INFO_OFFSET 0x21000

00112: #difine MAGIC_BOOTLOADER 0x55AA1234

00113: #define MAGIC_APP 0x55AA5678

00114: #define MAGIC_IMAGE_END 0x55AAABCD

FIG. 2a is an executable binary file data generated after a flash memory (Flash Memory, generally abbreviated as FLASH) operation. As shown in Figure 2a, by writing the FLASH operation to the structure, in the actual generated file, 0x21000 is the actually written data. Since this address corresponds to the markup code part, the generated file data cannot be compressed and must be stored in the actual occupied byte size.

Exemplarily, for the following executable binary file data:

00303: #difine BIN_PACKAGE_HEADER_ID0 0x54454C09

00304: #difine BIN_PACKAGE_HEADER_ID1 0x58336900

00289: PlaceU32_(BIN_PACKAGE_HEADER_ID0),

PlaceU32_(BIN_PACKAGE_HEADER_ID1)

Specifically, FIG. 2b shows another executable binary file data generated after the FLASH write operation. As shown in Figure 2b, those skilled in the art can understand that in the binary file, the data corresponding to the address 0002100h is consistent with the written data (54454C09 and 58336900), indicating that this part of the data in the binary file can be is compressed.

By analyzing the functional attributes of the data of each part of the executable binary file, the target data that can be compressed in the binary file can be quickly identified, so as to quickly lock the compressible, that is, the object to be processed, and narrow the scope of processing.

S130: Obtain a compression strategy for the target data according to the storage format attribute of the target data.

Exemplarily, different storage format attributes correspond to different compression strategies. E.g:

If no storage attribute with any compression flag is added to the storage path corresponding to the target data, it means that the target data is not compressed at all. Accordingly, the next compression strategy for the target data can be obtained, that is, the part of the data can be compressed according to a certain compression method, thereby reducing the storage space of the target data;

If the target data is stored in the corresponding path in the form of the first preset storage format (for example, the identifier is “-g”), it means that the target data is currently compressed by a compression method with a relatively low compression rate. Accordingly, the next compression strategy for the target data can be obtained, that is, the part of the target data can be compressed in a compression method with a higher compression rate than the current one;

If the target data is stored in the corresponding path in the form of the second preset storage format (for example, the identifier is "-7"), it means that the target data can currently be compressed by a compression method with a relatively high compression rate. Based on this, it is possible to obtain the next compression strategy for the target data, that is, it may not be possible to further improve the compression rate of this part of the target data by changing the compression method.

S140: Compress the target data according to the compression strategy, and update the storage format attribute of the target data to obtain a compressed executable file.

For the compressible target data, according to the compression strategy determined in the above steps, it can be compressed, and at the same time, the storage format attribute in the storage path corresponding to the target data can be updated, so that the storage format attribute of the compressed target data is the same as Corresponds to the current compaction strategy. Therefore, it is convenient to select the decompression strategy corresponding to the current compression strategy when the target data is executed. Therefore, by identifying the storage format attribute of the target data, it can be determined whether the target data is compressed, or in what way it is compressed.

Further, after saving the compressed executable file in the FLASH, for the remaining storage space of the FLASH, the remaining space of the FLASH can be fully utilized to store data, so that the utilization rate of the FLASH memory space can be maximized. Specifically, the optimization method is as follows:

FIG. 3 a is a distribution diagram of the data storage structure of the TV FLASH memory before optimization provided by Embodiment 1 of the present invention. As shown in Fig. 3a, in the storage space of 0-57BANK (storage unit), executable files of software are mainly stored, so the maximum size of executable files is 58*64K=3712K. If the size of the executable file is larger than this space, there is a risk of overwriting the data area. For data other than executable files, the storage space is allocated according to the size of the actual structure and the actual number of channels. After all the data is stored, there is only 2K available space left, that is, the storage space margin is insufficient. Therefore, in order to optimize the storage space to meet the requirement of simplification, it is necessary to save another BANK among the 7 BANKs in Fig. 3a to store data. The specific optimization process is as follows:

After analysis, in the 63rd BANK, the real data is only 304 BYTEs, but the storage space of FLASH is divided by BANK as a unit, so the data of 304 BYTEs in the 63rd BANK occupies the entire 63rd BANK. BANK, resulting in a waste of FLASH storage space resources. FIG. 3 b is a distribution diagram of the data storage structure of the optimized TV FLASH memory provided by Embodiment 1 of the present invention. As shown in FIG. 3b, by upgrading the HDCP, the data of the high-bandwidth digital content protection (High-bandwidth Digital Content Protection, HDCP) part can be directly written into the specified memory (such as the 58th BANK). In this way, one more BANK can be saved to store other program codes. In addition, the data storage method can also be modified to not save. The entire table will be initialized when the system is initialized, and then when switching between different timings, the data can be directly loaded from the table, which can save another BANK come out. Therefore, by adopting the above method of optimizing memory allocation, the technical effect of further saving storage space can be achieved.

Optionally, for the method of saving storage space, those skilled in the art can understand that, for the pictures that are not needed in the subsequent program execution, they can be deleted in the program data, or the pictures can be compiled Modify the compression rate of the picture from time to time to reduce the size of the executable file that generates the picture, and further save the storage space required by the program.

Optionally, the mode of masking the codes that do not need to be executed in the program can be changed to the mode of directly deleting the codes that are masked so that they cannot be executed, so as to achieve the technical effect of further saving the storage space of the executable file. Because the technical means of shielding the code is only to not execute this part of the code, but in the original executable binary file, this part of the shielded non-executable code still physically exists in the original executable binary file, so this Partially shielded code still occupies a certain amount of physical storage space. If the code that is shielded from being executed deliberately is directly deleted, since the code is physically deleted, compared with the technical means of shielding from execution, deleting the code will further save executable binary Storage space for files.

This embodiment provides a method for compressing an executable file. After analyzing the functional attributes and storage format attributes of each part of the executable file, according to the functional attributes such as storage, compression or decompression of the data of each part of the executable file, the Object data that can be compressed among portions of the executable file is identified. According to the storage format attribute of the target data, the compression strategy of the target data can be obtained. Wherein, the compression strategy may include no compression, compression, compression by a new compression method with a higher compression ratio than the original one, and compression by a new compression method with a smaller compression ratio than the original one. According to the compression strategy, the target data is compressed, and the storage format attribute of the target data is updated to obtain a compressed executable file. By adopting the above technical solution, the compressed executable file can occupy less storage space, achieving the technical effect of saving the cost of storage hardware materials required by the executable file, thereby indirectly improving the market competitiveness of corresponding products.

Embodiment two

FIG. 4 is a flowchart of a method for compressing an executable file provided by Embodiment 2 of the present invention. On the basis of Embodiment 1, this Embodiment 2 further optimizes the step S130 of Embodiment 1 "obtaining the compression strategy of the target data according to the storage format attribute of the target data". Referring to FIG. 4, Embodiment 2 of the present invention Specifically include the following steps:

S210: Analyzing the functional attributes and storage format attributes of the data in each part of the executable file.

S220: Identify compressible target data in each part of data according to the functional attribute.

S230: Determine whether the current storage format matches the preset storage format, if yes, execute step S240; otherwise, execute step S260.

Exemplarily, the compressible target data identified in step S220 may be data that has undergone compression processing, or may be data that has not undergone any compression. Therefore, by comparing the current storage format of the target data with the preset storage format, if the two do not match, it may be possible to indicate that the target data is uncompressed data. If the current storage format matches any of the preset storage formats, it may indicate that the current target data is compressed according to the compression rate corresponding to the preset storage format. Therefore, step 230 can be used as a basis for determining the compression strategy of the current target data. After the compression strategy is determined, an appropriate compression method can be selected to further compress the current target data, thereby saving the storage space occupied by the target data.

S240: Determine whether the current storage format matches the first preset storage format corresponding to the first compression strategy, if yes, execute step S250; otherwise, execute step S260.

Exemplarily, on the premise that the current storage format of the target data matches the preset storage format, if it is further determined that the current storage format corresponds to the first preset storage format of the first compression strategy (for example, the identifier is "-g" ), it indicates that the target data has been compressed according to the first compression strategy. At this time, the compression strategy of the target data can be changed according to actual needs, and at the same time, the original first preset storage format of the target data (such as the identifier is "-g") can be modified correspondingly to improve the compression rate of the target data , to achieve the technical effect of saving executable file storage space and saving storage material costs.

Exemplarily, it can be further judged whether the current storage format matches the second preset storage format corresponding to the second compression strategy (for example, the identifier is "-7"), and if so, it can indicate that the target data has been compressed according to the second Policies are compressed. At this time, the compression policy of the target data can also be changed according to actual needs, and at the same time, the original second preset storage format (eg, the identifier is "-7") of the target data can be correspondingly modified.

S250: Compress the target data according to the second compression strategy corresponding to the second preset storage format, wherein the compression ratio corresponding to the second compression strategy is greater than the compression ratio corresponding to the first compression strategy, and continue to execute step S270.

Exemplarily, if the first preset pre-storage format (for example, the identifier is "-g") in the target data is modified to the second preset storage format (for example, the identifier is "-7), the target data can be upgraded The compression ratio saves storage space. Specifically, Fig. 5 is a schematic diagram of the comparison of the storage space occupied by an executable file before and after compression for a kind of executable file provided by the embodiment of the present invention. As shown in Fig. 5, the uncompressed file (vdplayer. bin) needs to occupy the size of the file itself in the storage space to save storage space (1270KB); and for the compressed file (vdplayer.bin), it takes up a small part of the storage space (380KB).

Exemplarily, in some specific cases, for some target data, according to actual needs, if it is not necessary or appropriate to use a large compression ratio for compression, the second preset storage format (such as the identifier is "- 7") is modified to the first preset storage format (for example, the identifier is "-g"), so as to save the storage space occupied by the target data according to the characteristics of the target data itself.

S260: Determine the compression policy of the target data according to the preset storage format, and continue to execute step S270.

Exemplarily, if the current storage format of the target data does not match the preset storage format, it may indicate that the target data has not been compressed. At this time, the preset storage format (for example, it can be the first preset storage format or the second preset storage format) can be added to the storage path corresponding to the target data. When compressing the target data, the editor can The target data is compressed according to the compression methods corresponding to different storage formats, and the target data with different compression ratios are obtained, so as to save the storage space of the target data in the executable file and reduce the hardware cost required for storing the executable file.

S270: Compress the target data according to the compression strategy, and update the storage format attribute of the target data to obtain a compressed executable file.

In the second embodiment, on the basis of the above-mentioned embodiments, by matching the current storage format of the target data with the preset storage format, different compression strategies are adopted according to the matching results, and correspondingly added according to the selected compression strategy. Or change the original storage format attribute of the current target data to the new storage format attribute, so that the compression method of the target data can be added or changed accordingly according to actual needs, and then the compression rate of the target data of the executable file can be improved, saving the cost of the target data. It takes up storage space and indirectly achieves the technical effect of saving storage material costs.

The following is an embodiment of an executable file compression device provided by an embodiment of the present invention. The executable file compression device and the executable file compression method provided by the above embodiments belong to the same inventive concept.

Embodiment three

FIG. 6 is a structural block diagram of an executable file compression device provided by Embodiment 3 of the present invention. The device may be realized by software and/or hardware deployed in a TV and/or a TV set-top box, wherein the device may generally be integrated in an embedded system of a hardware entity such as a TV and/or a TV set-top box.

As shown in FIG. 6 , the device includes: an attribute analysis module 310 , a target data identification module 320 , a compression policy determination module 330 and a compression module 340 . in,

An attribute analysis module 310, configured to analyze the functional attributes and storage format attributes of the data of each part of the executable file;

A target data identification module 320, configured to identify compressible target data in each part of the data according to the functional attributes;

A compression strategy determination module 330, configured to obtain a compression strategy for the target data according to the storage format attribute of the target data;

The compression module 340 is configured to compress the target data according to the compression strategy, and update the storage format attribute of the target data to obtain a compressed executable file.

This embodiment provides a compression device for executable files. First, it analyzes the functional attributes and storage format attributes of each part of the executable file data, and can identify Extract the compressible object data in each part of the executable file. According to the storage format attribute of the target data, the compression strategy of the target data can be obtained. Wherein, the compression strategy may include no compression, compression, compression by a new compression method with a higher compression ratio than the original one, and compression by a new compression method with a smaller compression ratio than the original one. According to the compression strategy, the target data is compressed, and the storage format attribute of the target data is updated to obtain a compressed executable file. By adopting the above technical solution, the compressed executable file can occupy less storage space, achieving the technical effect of saving the cost of storage hardware materials required by the executable file, thereby indirectly improving the market competitiveness of the corresponding product.

On the basis of the foregoing embodiments, the compression policy determination module 330 may further include:

A compression strategy determining unit, configured to determine a compression strategy for the target data according to the current storage format if the current storage format of the target data matches a preset storage format.

On the basis of the above embodiments, the compression policy determination unit is specifically configured to:

If the current storage format matches the first preset storage format corresponding to the first compression strategy, the compression strategy of the target data is:

Compressing the target data according to a second compression strategy corresponding to a second preset storage format, wherein a compression ratio corresponding to the second compression strategy is greater than a compression ratio corresponding to the first compression strategy.

On the basis of the foregoing embodiments, the compression policy determination module 330 may also be specifically configured to:

If the current storage format of the target data does not match the preset storage format, then determine the compression policy of the target data according to the preset storage format.

Based on the above embodiment, the first preset storage format is "-g", and the second preset storage format is "-7".

The executable file compression device provided by the embodiments of the present invention can execute the executable file compression method provided by any embodiment of the present invention, and has corresponding functional modules and corresponding beneficial effects for executing the method. For technical details not exhaustively described in the foregoing embodiments, reference may be made to the executable file compression method provided in any embodiment of the present invention.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention, and the present invention The scope is determined by the scope of the appended claims.

Claims (10)

1. a compression method of executable file, is characterized in that, described method comprises: Analyzing the functional attributes and storage format attributes of the data in each part of the executable file; Identifying compressible target data in each part of data according to the functional attributes; Obtaining the compression policy of the target data according to the storage format attribute of the target data; According to the compression strategy, the target data is compressed, and the storage format attribute of the target data is updated to obtain a compressed executable file. 2. The method according to claim 1, wherein the step of obtaining the compression policy of the target data according to the storage format attribute of the target data comprises: If the current storage format of the target data matches the preset storage format, then determine a compression strategy for the target data according to the current storage format. 3. The method according to claim 2, wherein the step of determining the compression policy of the target data according to the current storage format comprises: If the current storage format matches the first preset storage format corresponding to the first compression strategy, the compression strategy of the target data is: Compressing the target data according to a second compression strategy corresponding to a second preset storage format, wherein a compression ratio corresponding to the second compression strategy is greater than a compression ratio corresponding to the first compression strategy. 4. The method according to claim 1, wherein the step of obtaining the compression policy of the target data according to the storage format attribute of the target data further comprises: If the current storage format of the target data does not match the preset storage format, then determine the compression policy of the target data according to the preset storage format. 5. The method of claim 3, wherein, The first preset storage format is -g, and the second preset storage format is -7. 6. A compression device for an executable file, characterized in that the device comprises: An attribute analysis module, configured to analyze the functional attributes and storage format attributes of the data of each part of the executable file; A target data identification module, configured to identify compressible target data in each part of the data according to the functional attributes; A compression strategy determination module, configured to obtain a compression strategy for the target data according to the storage format attribute of the target data; The compression module is configured to compress the target data according to the compression strategy, and update the storage format attribute of the target data to obtain a compressed executable file. 7. The device according to claim 6, wherein the compression policy determination module comprises: A compression strategy determining unit, configured to determine a compression strategy for the target data according to the current storage format if the current storage format of the target data matches a preset storage format. 8. The device according to claim 7, wherein the compression strategy determination unit is specifically configured to: If the current storage format matches the first preset storage format corresponding to the first compression strategy, the compression strategy of the target data is: The target data is compressed according to a second compression strategy corresponding to a second preset storage format, wherein a compression ratio corresponding to the second compression strategy is greater than a compression ratio corresponding to the first compression strategy. 9. The device according to claim 6, wherein the compression policy determination module is specifically used for: If the current storage format of the target data does not match the preset storage format, then determine the compression policy of the target data according to the preset storage format. 10. The apparatus of claim 8, wherein: The first preset storage format is -g, and the second preset storage format is -7.