CN1312550C - Method for dumping data to mobile storage medium and extracting data therefrom - Google Patents

Abstract

A method for dumping data originally stored in files to a removable storage medium, the method comprising: (A) reading multiple files specified by parameters one by one, connecting and merging them in memory to form a byte stream , called the original stream; (B) compress the original stream to form another byte stream, called the storage stream; (C) calculate the byte accumulation sum of the storage stream; and (D) store the interface flag, the storage stream Length, original stream length, byte accumulation and storage stream content written to removable media. In addition, a corresponding method for extracting data from removable media and restoring them to files is provided. Wherein, the data access (reading/writing) on the removable storage medium is not embodied in the form of files, thereby avoiding computer virus infection and prohibiting virus transmission.

Description

A method of dumping data to and extracting data from removable storage media

field of invention

The core of the present invention is a method for dumping data onto a removable storage medium and extracting data therefrom. The removable storage medium mainly refers to a floppy disk, a U disk, a removable hard disk, etc., wherein the 3.25-inch floppy disk (capacity 1.44M) is Mainstream small amount of data frequently reported storage media.

Background technique

The dumping, transmission, extraction, and reuse of data are data exchange activities, and the transfer through mobile storage media is realized by traditional and simple technology. The construction of computer network provides a better platform for the realization of data exchange, but due to the following reasons, the scheme of using mobile media to transmit data still has sufficient application basis and broad application stage for a period of time.

One of the reasons: the deployment of the computer network is always in accordance with a certain plan, restricted by economic, geographical and other environmental factors, it can only be considered in the long run, and it is generally built in stages and regions, and it is difficult to achieve all in place in a short period of time .

The second reason: the network within a certain industry needs long-term efforts to complete the construction, and the network connection between industries has introduced many more complicated issues that need to be paid attention to. Among them, the level of network security has been greatly improved. Technology, management and maintenance all pose serious challenges. Therefore, for the sake of stable development, in a relatively long period of time, data exchange between industries cannot be widely realized through the network.

The third reason: some special applications, such as the periodic data transfer of a large number of branch offices, have very high requirements for network bandwidth in an instant, which is difficult to meet for a while.

Even in the traditional data reporting method, there are many differences in the specific technical implementation.

The easiest thing is to copy the files on the removable media and the fixed media. The first step is to compress the files before copying from the fixed media to the mobile media (when there are many files and a large amount of data, especially When the data redundancy is high, the benefit is obvious), and another final stored file is formed, that is, the compressed file is copied.

Both of the above two methods require the medium to be pre-formatted, have a file management structure supported by the operating system on the medium, and use the powerful and flexible file processing functions provided by the operating system, so the implementation is easy and the compatibility is good. However, nowadays computer viruses are rampant, and all kinds of files are just the objects of concern, places of residence and one of the important ways of transmission of viruses. In this way, when the mobile storage media is delivered to the target application environment, whether the data in it is pure, Whether it can be used with confidence is questionable.

Computer virus is a kind of malicious program fragment, mainly divided into two types: system type and file type. System-type viruses tamper with the startup part of the operating system, so they are also called boot-type viruses. Most of them compile exquisite and self-programmed codes. After tampering with system-type viruses, the virus will intercept the control of the system as soon as possible. File-type viruses are embedded in executable programs (.EXE/.DLL/.COM, etc.) or files (.DOC/.EML, etc.) The data and internal implementation are in self-contained files (.JPG/.TTF, etc.), and the system control is intercepted when the program is executed, the document is opened, or the internal function is called by the normal application according to the interface. A virus can have the above two characteristics at the same time. On the contrary, due to the lack of available resources (powerful file access function, network function, etc.) It is also not easy, and it is almost extinct now, that is, viruses that do not use the file system at all are basically no one interested in causing trouble, so files have become a particularly favored object of viruses.

To fight against viruses, we mainly start from two aspects: killing and preventing. Scanning and killing is to scan the storage medium to see if there is a virus inhabiting it, and then deal with it if it is found; prevention is to analyze the intention of the active process in the system on the basis of system monitoring, and if there is any abnormal performance (modify important sensitive data of the system or intrude on other processes, programs, etc.), are prohibited.

From the analysis of the virus mechanism above, today's computer viruses always seek shelter through file access. The various functions provided by the operating system facilitate the realization of positive applications, and viruses will also use them to make waves. Therefore, going in the opposite direction and not accessing data in the file system format supported by the operating system is a solution to avoid viruses.

If you do not access data in the form of files, you cannot use the file processing functions provided by the operating system, and you need to use a relatively low-level storage medium for direct access. This method has obvious disadvantages, that is, poor compatibility, which is manifested in two aspects: The first is that a specific program can only access specific data. On the contrary, to access specific data, a specific program needs to be written; the second is that the underlying media access technologies provided by different operating systems are not the same, and cannot be accessed like files. , to be realized in a unified way, at least it needs to be realized separately for various mainstream operating systems. Due to the existence of this defect, this technology is not suitable for use in general-purpose products, such as software tools such as word processing (Word/WPS, etc.), graphics and image processing (CorelDraw/PhotoShop, etc.); however, when examining special business software for various industries, However, I found that this technology has application value, because the industry software is just a specific program, and the data it processes is also a specific data. It does not deliberately pursue compatibility, and the higher the data security, the better. , that is to say, there is a reason for adopting the technical solution involved in the present invention; and another aspect of this technology with poor compatibility is the concrete realization of the core idea of the present invention.

Contents of the invention

In order to solve the above-mentioned problems about data security (mainly virus infringement), as well as other problems in the prior art not mentioned, the present invention is proposed.

According to one aspect of the present invention, there is provided a method of dumping data originally stored in a file onto a removable storage medium, the method comprising the following steps: (A) reading a plurality of files specified by parameters one by one, Connect and merge in memory to form a byte stream, which is called the original stream; (B) compress the original stream to form another byte stream, called the storage stream; (C) calculate the byte accumulation sum of the storage stream; And (D) sequentially writing the storage interface flag, the length of the storage stream, the length of the original stream, the accumulated sum of bytes, and the content of the storage stream to the mobile medium.

According to another aspect of the present invention, there is provided a method for extracting data from a removable medium and restoring it to a file, the method comprising the following steps: (A) reading the first storage unit of the removable medium, and judging whether there is storage Interface flag, continue only when satisfied; (B) Obtain the length of the storage stream, the length of the original stream, and the accumulated sum of bytes; (C) Read the data in a certain number of storage units according to the length of the storage stream, that is, read the content of the storage stream ; (D) recalculate the byte accumulation sum of the stored stream content just obtained, and compare it with the byte accumulated sum obtained in step (B), and continue if it is the same; (E) decompress the stored stream, restore the the original stream; and (F) further restore the original data file according to the structure of the original stream, save it in the path specified by the parameter, and maintain the original file name.

Description of drawings

The above and other objects, features, and advantages of the present invention will be apparent from the following detailed description.

Fig. 1 has provided the general flowchart according to the embodiment of the present invention;

Fig. 2 has provided the flow chart that is used for dumping data to mobile medium according to the embodiment of the present invention;

Fig. 3 has provided the storage layout of the floppy disk according to the embodiment of the present invention;

Figure 4 shows the internal data structure of the original stream according to an embodiment of the present invention; and

Fig. 5 shows a flowchart for extracting data from a removable medium according to an embodiment of the present invention.

Detailed ways

Referring to the accompanying drawings, the embodiments of the present invention are described in detail as follows.

As shown in Figure 1, the data to be dumped is firstly extracted by specialized industry application software to form a data file. Special industry application software is not the invention point of this application, and it will not be described in detail here, but there should be such a consensus: although special industry application software is different, they have obvious commonality, that is, the data exchanged externally saved in the file. Next, the formed data file is dumped to a removable medium through the processing shown in FIG. 2 . Then, move media such as floppy disk, U disk, and active hard disk transfer according to the industry application deployment plan. Next, through the processing shown in FIG. 3, the data is extracted from the mobile medium, and the data file is re-formed on the fixed medium at the data application site. Finally, specialized industry application software processes the data in the form of files to continue the business process.

It should be noted that most of the data exchange involves regular or irregular frequent submission of a small amount of data, and floppy disks are still the mainstream storage medium for data submission due to their low cost, so the process description in the accompanying drawings and the following detailed descriptions use floppy disks as an example.

Referring to Figure 2, the main process of dumping data to removable media is described in detail, omitting some branch details that do not affect spiritual comprehension, such as error handling mechanisms such as file reading failure and removable media access failure.

In step 2A, read the multiple files specified by the parameters into the memory one by one, connect and combine them into a byte stream, called the original stream. The internal data structure of the original stream is shown in Figure 4.

In step 2B, the byte stream is compressed to form another byte stream, which is called a storage stream;

In step 2C, calculating the cumulative sum of the individual bytes of the storage stream; and

In step 2D, the storage interface flag, the length of the storage stream, the length of the original stream, the accumulated sum of bytes of the storage stream, and the content of the storage stream are sequentially written to the floppy disk.

Next, we will describe the storage location of the data processed in Fig. 2 in the floppy disk.

Starting from the first sector (boot area) of the floppy disk, according to the fixed structure, sequentially write the data of several consecutive sectors. After the data is written in this way, the boot area does not contain executable code, nor does it contain the radix table of the floppy disk. For the file system, it is just like a piece of raw media that has not been formatted. Operations that access data on a floppy disk. While losing compatibility, it resists the invasion of boot viruses, ensures the cleanliness of data, and reduces the risk of the application environment.

The storage layout of the floppy disk is shown in Figure 5.

Referring to Figure 3, the process of extracting data from removable storage media and restoring it to files is described in detail, omitting some branch details that do not affect spiritual comprehension, such as error handling mechanisms such as media access failure and file creation failure.

In step 3A, read the first sector of the floppy disk, judge whether there is an agreed storage interface mark, and continue if it meets, and end if it does not match;

In step 3B, the storage stream length, original stream length, byte accumulation and

In step 3C, read the data in a certain number of sectors according to the length of the storage stream;

In step 3D, calculate the byte accumulation sum of read data, compare with the accumulation sum (calculated before storing) obtained in step 3B, consistent just continue, otherwise promptly data verification fails, end;

In step 3E, identify the read data stream as a storage stream, decompress it, and restore the original stream;

In step 3F, restore the file according to the structure of the original stream, save the file in the path specified by the parameter, and maintain the original file name. Refer to Figure 4 for the structure of the above original stream.

Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific illustrations and exemplary embodiments shown and described herein. Accordingly, various modifications may be made thereto without departing from the spirit and scope of the general inventive concept as defined by the following claims and their equivalents.

Claims (2)

1. A method for dumping data originally stored in a file onto a removable storage medium, the method comprising the following steps: (A) Read multiple files specified by parameters one by one, connect and merge in memory to form a byte stream, called the original stream; (B) Compress the original stream to form another byte stream, called the storage stream; (C) computing the cumulative sum of bytes of the storage stream; and (D) Write the storage interface flag, the length of the storage stream, the length of the original stream, the accumulated sum of bytes, and the content of the storage stream into the mobile medium in sequence. 2. A method for extracting data from a removable medium and restoring it to a file, the method comprising the following steps: (A) read the first storage unit of the removable medium, judge whether it has a storage interface mark, and continue if it is satisfied; (B) Obtain the length of the storage stream, the length of the original stream, and the cumulative sum of bytes; (C) According to the length of the storage stream, read the data in a certain number of storage units, that is, read the content of the storage stream; (D) recalculate the byte summation of the storage stream content just obtained, and compare with the byte summation obtained in step (B), the same just continues; (E) decompressing the stored stream to restore the original stream; and (F) According to the structure of the original stream, the original data file is further restored, stored in the storage path specified by the number, and the original file name is maintained.

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