Method and system for expanding capacity of memory device

[0071] In order to facilitate a further understanding of the invention, specific embodiments of the invention will be described in detail below with reference to the accompanying drawings.

[0072] in figure 1 In the structure provided, a plurality of storage devices 11, 12, 13...1N constituting the storage device group 1 respectively establish connections with the storage expansion manager 2 and the storage expansion access controller 3 at the same time. The storage Devices 11, 12, 13...1N include local storage devices and network storage devices. Each storage device constituting the storage device group 1 is used to store data, and is expanded and managed by the storage expansion manager 2, and the I/O access to it is realized under the control of the storage expansion access controller 3.

[0073] The local storage device is a locally directly connected storage, including hard disks, electronic hard disks, Flash flash disks, optical storage devices, floppy disk drives with floppy disks, and other devices with data storage functions. Of course, hard disks, electronic hard disks, and Flash flash disks, etc., each of the memories includes storage media for storing data (such as hard disk disks, electronic hard disks, and Flash chips for Flash flash disks, etc.), and corresponding storage media for accessing storage media. Controlled storage controller (for example, hard disk controller, Flash storage controller). The network storage device is a storage device connected through a wide area network or a local area network, which includes a computer and a storage server connected through a local area network or a wide area network and directly connected to a memory.

[0074] Combine figure 2 The structure block diagram provided, its specific structure is:

[0075] Storage Expansion Manager 2 includes,

[0076] The extended index table 21 is used to record the connection address of each storage device in the storage device group 1, its basic storage unit ID number and its corresponding virtual ID number, and the association relationship of the above information (see image 3 );

[0077] The address collection module 22 is used to collect the storage device connection address and the ID number of each basic storage unit;

[0078] The virtual ID generator 23 is configured to generate a virtual ID number corresponding to the basic storage unit ID number in the extended index table 21.

[0079] Storage expansion access controller 3 includes,

[0080] The I/O request controller 31 is configured to provide the virtual ID number information in the extended index table 21 to the upper application or file system; and receive the I/O access request of the upper application or the file system, and forward it to the extended index Meter controller 32 and data transmission control module 34;

[0081] The extended index table controller 32 is used to provide the virtual ID number in the extended index table 21 to the upper application or file system through the I/O request controller 31 according to the standard hard disk sector number pattern; and according to the slave I/O request The I/O access request received by the controller 31 uses an index method similar to a standard hard disk to traverse the extended index table 21, locate the virtual ID number of the accessed basic storage unit and its offset, and send it to Address translator 33;

[0082] The address translator 33 is used for the virtual ID number and offset obtained from the extended index table controller 32, according to the connection address of the storage device, the basic storage unit ID number and the virtual ID number recorded in the extended index table 21 The association relationship of is translated into the connection address of the storage device, the ID number of the basic storage unit and the offset and sent to the data transmission control module 34;

[0083] The data transmission control module 34 is used to obtain the connection address of the storage device and the ID number and offset of the accessed basic storage unit according to the address translator 33 and the I/O access type obtained from the I/O request controller 31 , Relevant data and other information are sent to the designated storage device, and I/O access results and related data returned from the storage device are received. When the local storage device is accessed, the above information is directly sent to the storage controller of the storage device through the connection port of the storage device, such as the disk controller of the hard disk; when the access is a network storage device, the above information is generated into the network The access control packet is sent through the network to the network address where the network storage device is located, and the network access control packet is parsed and sent to the storage controller of the storage device through the storage device connection port.

[0084] Among them, the extended index table 21, as the core part of the storage expansion manager 2, is connected to the address acquisition module 22 and the virtual ID generator 23 at the same time, and is connected to the expansion index table controller 32 and the address translator of the storage expansion access controller 3. 33 is connected, and the address collection module 22 establishes a connection with the storage device group 1.

[0085] image 3 A structural schematic diagram of the extended index table 21 is provided, and a mapping relationship diagram between it and each basic storage unit in the related storage devices 11, 12, and 13 in the managed storage device group 1 is provided.

[0086] The extended index table 21 includes an address table 212 for recording the connection address of the storage device under management. The connection address varies according to the connection mode of the storage device. For a local storage device, it is the address of the connected port. The network storage device is its network address (such as IP address) and its connected port address; the ID address table 213 used to record the ID number of each basic storage unit of the managed storage device, the table records each corresponding ID number of the basic storage unit; a virtual ID table 211 for recording the virtual ID number corresponding to each basic storage unit.

[0087] The related information recorded in the virtual ID table 211, address table 212, and ID address table 213 are related to each other, and finally each virtual ID number in the virtual ID table 211 is mapped to a basic storage unit of a real storage device. in image 3 The provided structure is only described by way of example, and is not meant to be limited to the specific content described.

[0088] in image 3 In the provided embodiment, the client computer (of course can also be other devices with information processing capabilities) is connected to three independent storage devices 11, 12, 13 (of course, it can also be three data storage volumes or hard disk partitions) . The connection modes with the three storage devices are: the storage device 11 is a local storage device, which is a hard disk directly connected through the data channel (bus port) of the client computer, and the hard disk includes a plurality of sectors that can store data. , Its sector numbers are from 0201 to 0204, and the connected address is the address of the connected port. The connection address is recorded in the address table 212, and each sector number is recorded in the ID address table 213 correspondingly. The storage device 12 is a network hard disk, which is directly connected to the storage server or computer and connected to the client computer through the network. It includes multiple sectors with sector numbers 0301~0304, and the connected address is the one connected to it. The network address (such as the IP address) of the server or computer and the port address to which the hard disk is directly connected are stored, and the connection address of the hard disk and the corresponding sector number are also recorded in the address table 212 and the ID address mark 213. The storage device 13 is a network storage device similar to the storage device 12, but it is an electronic hard disk, which includes pages with page numbers 001 to 003, and also records accurate connection addresses in the address table 212 and the ID address table 213 And page number. The network may be a local area network, a wide area network, including Ethernet, optical fiber network, wireless data transmission network, and other data communication networks. The direct connection includes connecting the storage with a client computer, a computer, or a storage server using IDE, SCSI, SAS, FC (Fibre Channel), IEEE 1394, USB, and other methods. Correspondingly, the virtual ID number (virtual ID number for short) set for each basic storage unit described above is recorded in the virtual ID table 211. For example, for the 0303 sector in the storage device 12, its corresponding virtual ID The number is 007. According to the information in the extended index table 21, the corresponding hard disk sector can be found through its virtual ID number-007. Thus, the basic storage unit of the real storage device can be managed and controlled through the management and control of the virtual ID number. In order to facilitate effective management and control, the basic storage units of different storage devices should be of uniform size, for example, 512B—in fact, different sizes can also be used, but one more description of the basic storage unit space attributes is required. In the description of this application file, the basic storage units are all of a uniform size.

[0089] Through the above-mentioned method, multiple storage devices are managed, and virtualized into a "large memory" whose storage capacity is the sum of the storage capacities of multiple storage devices. The extended index table controller 32 provides the virtual ID number to the upper application program and/or the file system through the I/O access controller in the manner of the standard hard disk sector number.

[0090] Because the storage (ie, optical fiber storage, such as fiber optic hard disk) connected to the client computer through FC (Fibre Channel), although it is a network storage device for the client computer, because this connection is for the client computer It operates as a local disk, that is, the optical fiber interface directly accessed by the client computer. Therefore, in this application document, the optical fiber storage directly connected to the client computer through FC is described as a local storage device. The said local storage devices are all relative to the client computer, and the local connection of the storage device refers to the memory being directly connected to the memory through the port of the client computer bus.

[0091] As for network storage devices, it is also relative to client computers. It means that the client computer is connected to the storage server or computer through the network, and the storage server and the computer are directly connected to the storage. Such computers and storage servers directly connected to the storage are called storage. Node, the client computer is connected to the storage node through the network, and can access the storage directly connected to it through the storage node.

[0092] Figure 4 Provides an embodiment in which 4 storage devices are connected to form the storage device group 1. By implanting the storage expansion manager 2 and the storage expansion access controller 3 in the client computer 4, the client computer 4 is directly connected to one The local hard disk a is connected to a storage server 5 and a computer 6 through a network. The storage server 5 is connected to two optical hard disks, namely hard disks b and c, and the computer 6 is connected to an electronic hard disk. The storage server 5 and the computer 6 connected to the storage device constitute a storage node.

[0093] Figure 5 Provides a block diagram of the relevant parts when using network storage devices. At this time, the address acquisition module 22 is composed of an address receiver 221 respectively set on the client computer 4 and an address transmitter 222 set on the storage server 5; the data transmission control module 34 includes a data transmission master set on the client computer 4. The control unit 341 and the data access transmission control unit 342 arranged on the storage node 56; each of the above-mentioned parts is connected to the corresponding network equipment 41, 42 which is connected through the network to realize the network transmission of data between each other. The storage node 56 is connected to a hard disk, and the hard disk includes a disk controller 1a and a disk 1b. The components of the address acquisition module 22 and the data transmission control module 34 described above can be implanted in the client computer 4 and the storage server 5 in the form of computer programs. The aforementioned storage nodes include 56, a storage server 5 directly connected to a storage device, and a computer 6 directly connected to a storage device. The hard disk may also be other types of storage devices such as electronic hard disks (both include storage controllers and storage media) .

[0094] The address transmitter 222 collects the network address (such as IP address) of the storage node, which is also the IP address of the hard disk, the hard disk connection port number, the available sector number on the hard disk, etc., and sends it to the address receiver in the form of network data packets according to the network transmission protocol The address receiver 221 records the above-mentioned information in the extended index table 21; the data transmission main control unit 341 converts the I/O access request directed to the network hard disk into a network access control packet, and sends it to the data access control packet according to the network transmission protocol. The transmission control unit 342, the data access transmission control unit 342 parses the network access control packet and sends it to the disk controller 1a to achieve access to the disk, and the packet access result is transmitted back to the data transmission main control unit 341 through the network, and the data transmission main The control unit 341 then sends the access result to the I/O request controller.

[0095] Image 6 Provides a schematic diagram of the data structure of the network access control packet, which includes the IP address D1, the storage device connection port address D2, and the access result return address D3 of the accessed storage device (for the storage device IP address D1, the access result return address D3 is not necessary, because according to the TCP/IP protocol, the destination address and the originating address are recorded in the network data packet. Of course, in order to better improve the accuracy of access and the reliability of data transmission, the receiving end can Check to ensure that the data transmission is more accurate), access type D4, the starting ID number of the basic storage unit accessed and offset D5, for write access, it also includes the data to be written D6 that needs to be written into the basic storage unit And other information.

[0096] The access result returned from the storage server generates an access result data packet in a similar structure, which includes the IP address of the accessed storage device, the access port address of the accessed storage device, the return address of the access result (IP address), and the type of access , The starting ID number and offset of the accessed basic storage unit, access result status, and for read access, it also includes the accessed data.

[0097] In the present invention, a storage device group composed of a plurality of storage devices is expanded and managed by the expansion index table 21 to form a virtual large storage device. The virtual ID table 211 in the expansion index table 21 that records related information of the plurality of storage devices Provided to the file system and/or upper-layer applications in the form of standard hard disks. At this time, for the file system and upper-layer applications, all storage devices recorded in the extended index table 21 are used as a large, true and complete storage device. , And are allocated and managed by the file system or used by upper-layer applications, and the virtual ID number recorded in the virtual ID table 211 is used to establish relevant index information.

[0098] To put it simply, take the hard disk as an example. When the access terminal (client computer) needs to access a certain sector, the storage expansion access controller first accesses the virtual ID number in the expansion index table, and determines the corresponding sector according to the associated information. If it is a local storage device, read the sector number and send it to the corresponding disk. The disk controller executes the access task according to the sector number and access type, and returns the access result to the storage expansion access Controller; if you are accessing a network storage device, read the sector number, pack the access type and sector number together, and send it to the storage node (storage node) of the corresponding address through the network according to the network address connected to the accessed network storage device Server or computer), the storage node parses out the sector number, access type and other information, sends it to the corresponding disk controller for access, and sends the access result back to the access terminal through the network.

[0099] The control and management mechanisms for index information during access are consistent with the access of standard hard disks, so I won’t repeat them here. In order to facilitate a deeper understanding of the present invention, the specific working steps of the present invention are described below. The following description mainly explains how to access the real storage device by extending the index table. The following are all Figure 4 A structural block diagram of the embodiment is provided for description. The client computer 4 is used as the access terminal for initiating the access request, and the relevant program implementing the present invention is implanted in the client computer 4, and the storage server 5 and the computer 6 are also implanted. In order to gain a better understanding of the present invention, the specific description will also refer to the content recorded in other drawings.

[0100] Reference and Figure 7 The work flow chart provided,

[0101] In step S11, the client computer 4 connects multiple storage devices to form a storage device group 1. The storage device includes a local storage device and a network storage device. The local storage device is a hard disk a, and the hard disk a can be an independent hard disk or a logical partition of a hard disk; the network storage device is shared by the storage server 5 and its connected optical fiber hard disk arrays including hard disks b and c The network storage device formed by the network storage device also includes a network storage device formed by a computer and an electronic hard disk connected to it.

[0102] Step S12, the address collection module 22 collects the connection address of each connected storage device, refer to figure 2 , Figure 4 The structure, the steps specifically include,

[0103] The client computer 4 first scans the locally connected storage, finds all the local storages through scanning, and selects the required storage according to the needs. Figure 4 In the structure, that is, the local hard disk a. Of course, the hard disk a can be only a part of the local storage device connected to the client computer 4. That is, in addition to the hard disk a connected to it, it can also include other memories, but other memories are not used as the original The component part of the storage device group 1 of the invention is used by the client computer 4 as other independent storage. Since it does not belong to the content of the present invention, it is not described in the figure. The address collection module 22 collects the connection port address of the selected hard disk a on the client computer 4 according to the scanning result and the selection, and records it in the address table 212 of the extended index table 21.

[0104] Reference Figure 5 and Figure 4 As shown, for the network storage device, logically add the network address where the network storage device is located—the network address of the storage node—such as the IP address in the client computer 4 as required. The address receiver 221 accesses the device through the network device 41. Network address, and send port collection control information to the network address. The address transmitter 222 collects control information through the receiving port of the network device 42 and collects the connection port addresses of all available memories of the storage node, and sends it to the address via the network device 42 The receiver 221, the memory on the network address selected by the client computer 4 according to needs, and the address receiver 221 records the network address and the connection port address of the selected memory in the address table 212 of the extended index table 21. in Figure 4 In the structure, the storage node 56 includes a storage server 5 and a computer 6. The storage server 5 is directly connected to two optical hard disks via FC, namely hard disks b and c, and the computer 6 is directly connected to an electronic hard disk. In this step, the address transmitter 222 on the storage server 5 and the computer 6 collects control information according to the address sent by the address receiver 221, and connects the hard disks b and c on the storage server 5 and the electronic hard disk on the computer 6. The port is sent to the address receiver 221 and recorded in the address table 212.

[0105] Step S13: The address collection module 22 collects the ID number of the basic storage unit of the memory selected in step S12 and records it in the ID address table of the extended index table 21, which specifically includes:

[0106] For hard disk a, because it is a local storage device, the address collection module 22 collects all available sector numbers of hard disk a for storing data through the disk controller of hard disk a, and records them in the ID address table of the extended index table 21, and makes hard disk a The port address of the connection port corresponds to each available sector number.

[0107] For the hard disks b and c, since they belong to network storage devices, the address receiver 221 sends the address ID number collection control information to the address transmitter 222 on the storage server 5 through the network devices 41 and 42, and the address transmitter 222 uses the hard disks b, c. The disk controller collects all available sector numbers and sends them back to the address collector 221 through the network devices 41 and 42, and records the sector numbers of the hard disks b and c corresponding to their connection addresses in the ID address table of the extended index table 21 213 in. Similarly for electronic hard disks, the same method is adopted to collect all available page numbers, and the page numbers are corresponding to the connection addresses of the electronic hard disks, and the page numbers are recorded in the ID address table.

[0108] Of course, in practical applications, steps S12 and S13 can be implemented in combination, that is, the connection port address of the memory, the sector number, and the page number (basic storage unit ID number) are collected together and recorded in the extended index table 21 respectively.

[0109] Step S14: According to the collected ID numbers of the basic storage units of all storage devices, the virtual ID generator 23 generates a different virtual ID number for each basic storage unit. The virtual ID numbers themselves are generally continuous, which is convenient for management. And control. When generating the virtual ID number, the virtual ID number can be generated sequentially according to the ID number of the basic storage unit of each storage device, or it can be independently calculated and generated without using it as a reference. Particularly, consecutive virtual ID numbers can be segmented to correspond to different storage devices. For example, virtual ID numbers 001-010 and 030-040 can correspond to basic storage units on hard disk a, and virtual ID numbers 011-020, 050- 060 is the basic storage unit on the corresponding hard disk b, so that when reading and writing large data files, the data of each part of the file can be read and written from different hard disks to increase the read and write bandwidth. Each generated virtual ID number is associated with the corresponding storage device address and the ID number of the basic storage unit, and is recorded in the virtual ID table of the extended index table 21.

[0110] In step S15, the extended index table controller 32 provides the entire virtual ID number in the extended index table 21 to the upper application program or the file system. The extended index table controller 32 provides all the virtual ID numbers in the extended index table 21 as sector numbers of a standard hard disk to the upper application or file system. The process is equivalent to providing the virtual ID number as a sector number of a "large hard disk" to the upper file system or file system for use.

[0111] The upper application program realizes the access to the storage device through the virtual ID number, and the file system establishes the file system based on the virtual ID number.

[0112] After completing the above initialization information, when an upper-level application or file system issues an I/O access request pointing to the virtual "large hard disk", it regards all the virtual ID numbers in the extended index table 21 as a "large hard disk" All sector numbers are used, and directly point to the virtual ID number. Finally, the virtual ID number is used to find and point to the basic storage unit of the real memory according to the association relationship. The specific steps include the following:

[0113] In step S20, the I/O request controller 31 receives the I/O access request sent from the upper application program or the file system, and forwards the I/O access request to the extended index table controller 32.

[0114] Step S21: According to the received I/O access request, the extended index table controller 32 calculates and finds the access sector number from the virtual ID table 211 of the extended index table 21 according to the existing access standard hard disk. The virtual ID number of the basic storage unit is collected into the extended index table controller 32. The recording method of the collected virtual ID number of the basic archive unit to be accessed can be used to record the starting virtual ID number and offset of the basic storage unit. Of course, it can also directly calculate the basic storage unit to be accessed. The start and end range of the virtual ID number. Of course, it is preferable to have a method of recording the starting virtual ID number and its offset. This method can be used in the workflow of related steps. In the following description, this recording method is used as an example for description. Specifically, taking write access as an example, the extended index table controller 32 calculates the number of basic storage units required according to the size of the data to be written and the size of the basic storage unit, which is the deviation of the virtual ID number, namely

[0115]

[0116] Since the virtual ID number of the basic storage unit that needs to be accessed for an I/O access request may be discontinuous, in this case, it is necessary to record the starting virtual ID number and offset of each continuous part separately, and Record the sequence relationship, and all the various parts constitute all the virtual ID numbers that need to be accessed. The corresponding extended index table controller 32 sends the obtained starting virtual ID number and offset to be accessed to the address translator 33.

[0117] Step S22, the address translator 33 translates the initial virtual ID number and offset into the corresponding basic storage according to the association relationship recorded in the extended index table 21 according to the obtained initial virtual ID number and offset. The connection address of the memory where the unit is located and the start ID number of the corresponding basic storage unit, that is, the offset, are sent to the data transmission control module 34. In the method of recording the starting virtual ID number and the offset, only the starting virtual ID number needs to be translated during address translation. Of course, if the virtual ID number and offset are not on the same real memory, the above content needs to be decomposed, for example, refer to image 3 As shown, if the starting virtual ID number for an I/O access request is 003 and the offset is 4, at this time, when the address is translated, it points to the 0203 and 0204 sectors of the storage device 11, and The 0301, 0302, and 0303 sectors of the storage device 12 are now translated into two parts, that is, the starting ID number of the storage device 11 is 0203, the offset is 1, and the starting ID of the storage device 12 is The number is 0301 and the offset is 2.

[0118] Step S23, when the address translator 33 translates the virtual ID number and offset into the connection address of the real memory and the ID number of the basic storage unit, it judges that the memory is a local storage device according to the connection address of the memory (whether there is a network address), It is also a network storage device, and the judgment result and the translated connection address of the memory to be accessed, the starting ID number and offset of the basic storage unit to be accessed, etc. are sent to the data transmission control module 34. If it is a local storage device, Step S27 is directly executed, and if it is a network storage device, step S24 is executed.

[0119] Step S24, the data transmission main control unit 341 of the data transmission control module 34 extracts the IP address from the received connection address of the memory that needs to be accessed, and combines the memory IP address, memory connection port address, and access to the basic storage unit. Start ID number and offset, read the IP address of the client computer 4, and the access type obtained from the I/O request controller 31 (for write access, including data to be written), etc., are generated and recorded in the network access Control package. Specifically, the memory IP address, the memory connection port address, the IP address of the client computer 4, the access type, the starting ID number and offset of the basic storage unit to be accessed, and the data to be written are respectively recorded to the IP address of the storage device. D1, storage device connection port address D2, access result return address D3, access type D4, initial ID number and offset D5 of the basic storage unit accessed, and data to be written D6.

[0120] Generate network access control packets for access requests pointing to different memories. For those pointing to the same memory but with multiple sets of starting ID numbers and offsets, the relevant information corresponding to each set of starting ID numbers and offsets is The above methods respectively generate network access control packets.

[0121] In order to improve the efficiency of network transmission and access, and to facilitate the application of the client computer 4, the size of a single network access control packet can be set according to the network status and application environment.

[0122] The data transmission main control unit 341 sends the extracted IP address and network access control packet to the network device 41 together.

[0123] Step S25: The network device 41 uses the IP address as the destination address (that is, the storage node 56 to be accessed), reads the IP address of the client computer 4 as the initiation address, and uses the network access control packet as data to generate network data according to the communication protocol. The packet (IP packet) is sent to the network device 42 of the destination address (that is, the accessed storage node 56), and the network access control packet is parsed out and sent to the data access transmission control unit 342.

[0124] In step S26, the data access transmission control unit 342 parses the network access control packet, compares the IP address of the storage device therein with the IP address of the storage node, and if it does not match, discards the network access control packet; if it matches, analyzes the memory The address of the connection port, the type of access, the starting ID number of the accessed basic storage unit, that is, the offset, and possible data to be written.

[0125] Step S27, if it is a local storage device, the data transmission control module 34 obtains the access type from the I/O request controller 31 (for write access, it also includes the data to be written), and sets the access type and the starting ID number of the basic storage unit And the offset, and possibly the connection port address where the data to be written is sent to the memory, are sent directly to the memory controller of the designated memory.

[0126] If it is a network storage device, it is executed on the storage node 56. The data access transmission control unit 342 on the storage node 56 sets the type of access, the starting ID number and offset of the basic storage unit to be accessed, and possible write The data and the like are sent to the connection port address of the memory and transmitted to the memory controller of the memory.

[0127] In step S28, the storage controller accesses the corresponding basic storage unit on the storage medium to the designated basic storage unit start ID number and offset according to the access type. For example, write the data to be written into the designated basic storage unit on the storage medium, or read data from the designated basic storage unit.

[0128] In step S29, after the access is completed, the storage controller returns the access structure to the data transmission control module 34 and sends it to the I/O request controller 31, and the I/O request controller 31 returns it to the upper application or file system. The return of the entire access result is similar to that of a standard hard disk, except that this process is executed by the relevant part of the present invention, and the network storage device needs to return the access result according to the communication protocol. specifically is:

[0129] For a local storage device, the storage controller directly returns the access result to the data transmission control module 34 and sends it to the I/O request controller 31, which returns to the upper application or file system by the I/O request controller 31.

[0130] For network storage devices, on the storage node 56, the storage controller sends the access result back to the data access transmission control unit 342, and the access transmission control unit 342 sends the access result status and the IP address of the storage node (that is, the accessed storage device). The IP address), the storage device connection port address, the starting ID number of the basic storage unit accessed, that is, the offset, the access result return address (IP address), and the access result data packet for the data read by the read access, Send to the network device 42, the network device 42 uses the IP address returned by the access result as the destination address, and the IP address of the storage node as the initiation address, and sends the access result data packet to the client according to the communication protocol. The network device 41 of the end computer 4; the network device 41 analyzes the access result data packet from the network data packet and sends it to the data transmission master control unit 341; the data transmission master control unit 341 parses the IP address of the storage device from the access result data packet The address is compared with the IP address of the client computer 4, and if they match, the access result status, the starting ID number of the accessed basic storage unit, ie the offset, and the data read for read access are sent to the I/O request Controller 31.

[0131] Of course, the present invention can also have various other embodiments, and without departing from the spirit and essence of the present invention, even if the execution order of each step is changed, it falls within the protection scope of the present invention. Those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should fall within the protection scope of the appended claims of the present invention.