JP2006079492A - Difference data generation device, difference data generation method and difference data generation program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size of difference data in updating (version-up) the data such as a program. <P>SOLUTION: In a difference data generation device 100, a first difference data generation section 102 reads old data 192 and new data 191 stored on a data storage section 190 to generate difference data 193 before conversion using a conventional Move command code and an ADD command code. A second difference data generation section 130 generates difference data 194 after conversion using a particular Move command code not updating the value of the processing pointer of the new data after Move processing and using a Skip command code only updating the value of the processing point of the new data on the basis of the difference data 193 before conversion. A difference data output section 140 compares the data size of the difference data 193 before conversion with that of the difference data 194 after conversion to output the difference data having a smaller data size as the difference data. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a difference data generation apparatus, a difference data generation method, and a difference data generation program for data update.

  In an apparatus such as a personal computer or an embedded device (such as a mobile phone or a car navigation system), data such as a program handled by a processor may be updated (version up). When upgrading, send the difference data between the pre-update data and the post-update data to the device via the storage medium or the communication network, and apply the difference data to the pre-update data in the device to generate the post-update data. This method is common. Note that the difference data between the pre-update data and the post-update data is generated in advance in a device (difference data generation device) different from the device to be upgraded.

  Particularly in a system in which difference information is sent to a device using a wireless network having a narrow communication band, the size of the difference data is desirably small. Then, the difference data size can be reduced by devising the differential data expression method and extraction method.

FIG. 1 is a diagram showing old data 192 and new data 191.
When upgrading various data, especially programs for embedded devices and map data for car navigation systems, as shown in FIG. 1, the positions of the old data 192 and the new data 191 are misaligned and the misaligned portion. There are many pattern updates where the contents of the data are changed by jumping.
In FIG. 1, the contents of A and A ′, C and C ′, E and E ′, and G and G ′ are the same, and the contents of B and B ′, D and D ′, and F and F ′ are changed.

FIG. 2 is a diagram showing difference data according to a conventional example.
A general differential data expression method as differential data for the old data 192 and the new data 191 shown in FIG. 1 will be described with reference to FIG.
As a general differential data expression method, for example, Walter F. et al. There is a paper by Tichy "The String-to-String Correction Problem with Block Moves".
In this expression method, a Move instruction that means that data is moved from a part or all of the old data 192 and copied to the new data 191 and the data described in the difference data are added to the new data 191. This is a method of using the Add instruction meaning that the difference data is expressed.
When applied to the example of FIG. 1 (but limited to the range of A to G and A ′ to G ′), the difference between the old data 192 and the new data 191 can be expressed by the difference data as shown in FIG. .
Data migration from A to A ′, C to C ′, E to E ′, G to G ′ is represented by the Move instruction, and addition of new data to B ′, D ′, and F ′ is represented by the Add instruction. ing.
The Move instruction indicates the address where the target data is located in the old data as position information.
Since the Move instruction requires position information in the old data 192, in the case where the Move instruction and the Add instruction appear alternately as shown in FIG. 2, the position information of the Move instruction becomes one of the factors for increasing the difference data size. End up.

The difference data size is increased by the position information of the Move instruction, whereas the offset information of the new data 191 and the old data 192 is used for the Move instruction, and when the Move instruction is expressed, the offset information of the immediately preceding Move instruction is used. When the offset is the same, a method of omitting the offset information of the Move instruction is disclosed by setting a 1-bit flag to indicate that the offset is the same as the previous Move instruction (Patent Literature). 1).
The offset indicates a relative value when the migration data in the old data 192 is migrated to the migration position in the new data 191.
Normally, more data than 1 bit is required to indicate offset information (for example, 1 byte), so that the offset data can be omitted by the above method and the differential data size can be reduced.

Difference data with respect to FIG. 1 expressed by the method of Patent Document 1 has a format as shown in FIG.
When the position information of the Move instruction is represented by an offset for data transfer from A to A ′, from C to C ′, from E to E ′, and from G to G ′ shown in FIG. In FIG. 3, “+100”, which is the same continuous offset, is represented by 1-bit “flag”.

  However, in the differential expression method, when B ′ and F ′ can be expressed by a Move instruction from another position (H) of the old data 192 as shown in FIG. 4, the offsets of the Move instruction are continuously the same value. Therefore, omission of offset information using the flag is not very effective.

When the update from the old data 192 shown in FIG. 4 to the new data 191 is expressed by the method of Patent Document 1, it is as shown in FIG.
In this case, “flag” can be used only in one place, which indicates that the omission of offset information using a flag is not very effective.

As an effective method for the case shown in FIG. 4, Patent Document 1 discloses a method of expressing offset information frequently used in Move instructions by one or a plurality of bits. By this method, the differential data size can be reduced by expressing the offset information with one or a plurality of bits for the Move instructions A ′, C ′, E ′, and G ′ in FIG.
In FIG. 4, there are four Move instructions including “flag” with “+100” as an offset, and the differential data size is reduced by using a bit expression indicating “+100”.

  However, as shown in FIG. 6, in the case where A ′ is equal to not only A but also I and E ′ is not only equal to E but also J, the process disclosed in Patent Document 1 does not necessarily require A → A ′, E → The Move command E ′ is not always extracted as a difference. In the method of expressing the same offset by one or a plurality of bits, the difference data can be reduced if the same offset appears as much as possible. However, in the case shown in FIG. 6, I → A ′, J If the Move instruction is extracted as a difference, such as E ′, the effect of reducing the size of the difference data is reduced.

When the update from the old data 192 shown in FIG. 6 to the new data 191 is expressed by the method of Patent Document 1, it is as shown in FIG.
In this case, the same offset has only “+100” in two places, and “+100 flag” indicating a value of “+100” can only be used in two places. In addition, the effect of reducing the size of the difference data is reduced because it is necessary to have “+100 flag” unless it has other information indicating that the value is “+100”.
JP 2004-152136 A

  In a data update system for updating one version of data to another version, it is required to reduce the difference data size between the pre-update data and the post-update data. In such a situation, when updating various data, particularly programs for embedded devices and map data for car navigation systems, many patterns are updated as shown in FIGS. 1, 4, and 6. In this technique, even if there is a possibility that the difference data cannot be expressed with a small size or the difference data can be expressed with a small size with respect to the pattern as described above, it is not guaranteed that the difference data is extracted with such an expression. There was a problem.

  The present invention has been made based on the solution of the above-described problem. It is possible to express the difference data small in an update pattern that cannot be expressed in a small size with the conventional technology, and to express the difference data small. The purpose is to make it possible to accurately express the difference data when there is a possibility of being able to do so.

  The difference data generation device of the present invention includes a data storage unit that stores old data and new data, and reads the old data and new data stored in the data storage unit, and the position and copy size indicated by the old data pointer The data at the position indicated by the old data pointer is copied by the copy size from the position indicated by the new data pointer, and a value indicating the position moved by the copy size from the position indicated by the new data pointer is set in the new data pointer. Indicating whether to include the first Move instruction code indicating the difference data, additional data and additional data size, adding additional data from the position indicated by the new data pointer, and adding the position indicated by the new data pointer to the additional data size Whether the difference data includes an Add instruction code indicating that a value indicating the moved position is set in the new data pointer Indicates the position and copy size indicated by the old data pointer, indicates that the data at the position indicated by the old data pointer is copied from the position indicated by the new data pointer by the copy size, and the value of the new data pointer is not updated. Skip instruction code indicating whether to include the second Move instruction code in the difference data, the pointer update size, and a value indicating the position moved by the pointer update size from the position indicated by the new data pointer is set in the new data pointer And a difference data generation unit for generating difference data based on the determination result and storing the difference data in the storage unit.

  According to the present invention, for example, the difference data can be expressed in a small size in an update pattern that cannot be expressed in a small size in the conventional technique.

Embodiment 1 FIG.
First, a method for expressing difference data will be described.
In the differential data generation device, in addition to the conventional Move instruction (first Move instruction or first Move instruction code) and Add instruction (Add instruction code), a special Move instruction (second Move instruction or second Move instruction code) and a Skip instruction (Skip instruction code) ) Are used to express difference data.
The special Move instruction means moving the data from a part or all of the old data 192 and copying it to the new data 191, and then moving the rewrite pointer for the new data 191 to the head of the copy data.
The Skip instruction means that the rewrite pointer for the new data 191 is advanced forward by a specified length.

Here, an example of the format of each differential instruction is shown in FIG.
However, what is shown in FIG. 8 is merely an example for explanation, and does not indicate that the effect of the present invention is limited to the format shown in FIG.
The Move instruction is expressed by an instruction identifier 1 byte (byte) representing Move, an offset (Move offset) 2 bytes of the old data 192 and the new data 191, and a data length (Move size) 4 bytes of the Move target.
The Add instruction is expressed by an instruction identifier 1 byte indicating Add, a size (Add size) 2 bytes to be added, and contents (Add data) to be actually added. The size of the Add data is the Add size.
The special Move instruction is expressed by an instruction identifier 1 byte representing the special Move, an offset (special Move offset) 2 bytes of the old data 192 and the new data 191, and a data length (special Move size) 4 bytes of the Move target.
The Skip instruction is expressed by an instruction identifier 1 byte representing Skip and a size to be skipped (Skip size) 4 bytes.
Unlike the Move instruction and the special Move instruction, the Skip instruction does not require offset information, so that it can be expressed in a smaller size than the Move instruction and the special Move instruction.

FIG. 9 shows the difference data of the part from A ′ to G ′ in the update pattern shown in FIG.
The difference data is difference data when only the Move instruction and the Add instruction are used as a conventional method, and the position information of the Move instruction is expressed by an offset.
In this case, when the instruction format shown in FIG. 8 is used, there are four Move instructions (7 bytes), 28 bytes, Add instructions (3 bytes + Add size) are 13 bytes, 23 bytes, and 13 bytes, and the total size of the difference data is 77 bytes.

FIG. 10 shows the difference data of the part from A ′ to G ′ in the update pattern shown in FIG. 1 using a special Move instruction and a Skip instruction.
In the figure, the special Move instruction is indicated by “Move ′”.
After the data from A to G of the old data 192 is copied from A ′ to G ′ of the new data 191 by the first special Move instruction, the update pointer of the new data 191 is returned to the head of A ′.
Next, the update pointer is advanced by 100 bytes by the Skip instruction and moved to the head of B ′.
Next, data for 10 bytes of content of B ′ is added by the Add instruction.
Thereafter, the same processing is performed. It is possible to update between A ′ and G ′ by such differential data representation.
The size of the difference data in this case is 7 bytes for the special Move instruction, 4 bytes for the Skip instruction (5 bytes), 20 bytes, and 13 bytes for the Add instruction (3 bytes + Add size), 23 bytes, 13 bytes, which is 76 bytes in total, as shown in FIG. The size is smaller than the conventional difference data.
For the example of FIG. 1, the size of the difference data is only 1 byte, but the difference data becomes smaller as the number of Move and Add repetitions increases.

Note that the data update process from the old data to the new data performed using the difference data does not copy the Move size when the special Move instruction appears in the difference data, but the offset of the special Move instruction and the Move. The size is stored in the storage unit, and it is determined whether or not the target range of the Skip instruction is included in the Move range of the special Move instruction when the Skip instruction generated thereafter is applied, and if included, the Skip An instruction can be replaced with a Move instruction for processing.
The process of replacing the Skip instruction with the Move instruction can be performed by setting the offset of the special Move instruction as the Move offset and setting the Skip size of the Skip instruction as the Move size.
By this update processing, it is possible to avoid useless copy processing when the special Move instruction is processed as it is meant.
For example, in the example of FIG. 1, it is not necessary to copy to the B ′, D ′, and F ′ portions of the new data 191.

  Next, it will be described with reference to FIGS. 11 and 12 that the pattern of FIG. 4 which cannot efficiently express the difference data by the conventional method can be efficiently expressed.

FIG. 11 shows conventional difference data in which the position information is expressed by a Move offset and an Add instruction with respect to the update pattern of FIG.
The difference data in this case is 6 bytes for Move instructions, 42 bytes, and 23 bytes for Add instructions, for a total of 65 bytes.

FIG. 12 shows difference data expressed using the special Move instruction and Skip instruction for the update pattern of FIG.
The difference data in this case is 7 bytes for the special Move instruction, 14 bytes for the Move instruction, 14 bytes for the Skip instruction, 20 bytes for the Skip instruction, 23 bytes for the Add instruction, and a total size of 64 bytes, which is smaller than the conventional difference data shown in FIG. It has become.

  Further, when the offset omission flag of Patent Document 1 is used, the effect of the differential data size compression is reduced because the offset of the Move instruction is not continuous with the same value, whereas the special Move instruction is also illustrated in the update pattern of FIG. It can be used in the same manner as the update pattern 1 and the compression effect of the differential data size is not diminished.

In the above, if the difference data is generated using the special Move instruction and the Skip instruction, the size difference between the instruction size of the conventional Move instruction and the instruction size of the Skip instruction and the data size of the difference data can be reduced. Explained.
For this reason, the difference data can be made smaller than the conventional difference data as the use of the Skip instruction increases for the update pattern of FIG.

  Next, a difference data generation apparatus that generates difference data using a special Move instruction and a Skip instruction will be described.

FIG. 13 is a diagram illustrating an appearance of the difference data generation device 100 according to the first embodiment.
In FIG. 13, a differential data generating apparatus 100 includes a system unit 910, a CRT (Cathode Ray Tube) display device 901, a keyboard (K / B) 902, a mouse 903, a compact disk device (CDD) 905, a printer device 906, a scanner device. 907, which are connected by a cable.
Further, the differential data generating apparatus 100 is connected to a FAX machine 932 and a telephone 931 by a cable, and is connected to the Internet 940 via a local area network (LAN) 942 and a web server 941.

FIG. 14 is a hardware configuration diagram of the difference data generation device 100 according to the first embodiment.
In FIG. 14, the differential data generation device 100 includes a CPU (Central Processing Unit) 911 that executes a program. The CPU 911 includes a ROM 913, a RAM 914, a communication board 915, a CRT display device 901, a K / B 902, a mouse 903, an FDD (Flexible Disk Drive) 904, a magnetic disk device 920, a CDD 905, a printer device 906, and a scanner device 907 via a bus 912. Connected with.
The RAM 914 is an example of a volatile memory. The ROM 913, the FDD 904, the CDD 905, the magnetic disk device 920, and the optical disk device are examples of nonvolatile memories. These are examples of a storage device or a storage unit.
The communication board 915 is connected to a FAX machine 932, a telephone 931, a LAN 942, and the like.
For example, the communication board 915, the K / B 902, the scanner device 907, the FDD 904, and the like are examples of the information input unit.
Further, for example, the communication board 915, the CRT display device 901, and the like are examples of the output unit.

Here, the communication board 915 is not limited to the LAN 942 and may be directly connected to the Internet 940 or a WAN (Wide Area Network) such as ISDN. When directly connected to a WAN such as the Internet 940 or ISDN, the differential data generating apparatus 100 is connected to a WAN such as the Internet 940 or ISDN, and the web server 941 is unnecessary.
The magnetic disk device 920 stores an operating system (OS) 921, a window system 922, a program group 923, and a file group 924. The program group 923 is executed by the CPU 911, the OS 921, and the window system 922.

The program group 923 stores a program for executing a function described as “˜unit” in the description of each embodiment. The program is read and executed by the CPU 911.
In the description of each embodiment, the file group 924 includes what is described as “determination result of”, “determination result of”, “calculation result of”, and “processing result of”. Is stored.
In addition, the arrows in the flowcharts described in the description of each embodiment mainly indicate input / output of data. For the input / output of the data, the data is a magnetic disk device 920, an FD (Flexible Disk cartridge), an optical disk, It is recorded on other recording media such as CD (compact disc), MD (mini disc), DVD (Digital Versatile Disk). Alternatively, it is transmitted through a signal line or other transmission medium.

  In addition, what is described as “˜unit” in the description of each embodiment may be realized by firmware stored in the ROM 913. Alternatively, it may be implemented by software alone, hardware alone, a combination of software and hardware, or a combination of firmware.

  In addition, the program for implementing each embodiment may be stored using a recording device using another recording medium such as the magnetic disk device 920, FD, optical disk, CD, MD, or DVD.

FIG. 15 is an internal configuration diagram of the difference data generation device 100 according to the first embodiment.
In FIG. 15, the difference data generating apparatus 100 according to the first embodiment uses an old data pointer indicating the data position of the old data and a new data pointer indicating the data position of the new data in order to shift from the old data to the new data. Difference data including an instruction code (Move instruction code, Add instruction code, special Move instruction code, Skip instruction code) related to information to be controlled and data to be transferred is generated.
In addition, a data storage unit 190 and a difference data generation unit 110 are provided to generate difference data.

  The difference data generation unit 110 includes a difference data first generation unit 120, a difference data second generation unit 130, and a difference data output unit 140, and generates and outputs difference data.

The first difference data generation unit 120 performs the following processing based on the old data 192 and the new data 191 stored in the data storage unit 190.
Shows the position and copy size indicated by the old data pointer, copies the data at the position indicated by the old data pointer by the copy size from the position indicated by the new data pointer, and moves the value indicated by the new data pointer by the copy size. It is determined whether or not the first Move instruction code (conventional Move instruction code) indicating setting to the new data pointer is included in the difference data.
In addition, the additional data and the additional data size are indicated, the additional data is added from the position indicated by the new data pointer, and the value indicating the position moved by the additional data size is set in the new data pointer. It is determined whether or not an Add instruction code indicating “” is included in the difference data.
Based on the determination result, pre-conversion difference data 193 (difference data that does not use the special Move instruction and Skip instruction) is generated and stored in the data storage unit 190.

The second difference data generation unit 130 performs the following process based on the pre-conversion difference data 193 stored in the data storage unit 190.
A second Move instruction indicating the position indicated by the old data pointer and the copy size, copying the data at the position indicated by the old data pointer by the copy size from the position indicated by the new data pointer, and not updating the value of the new data pointer It is determined whether a code (special Move instruction code) is included in the difference data.
In addition, it is determined whether or not to include the Skip instruction code indicating the pointer update size and indicating that the value indicating the position moved by the pointer update size is set in the new data pointer in the difference data.
Based on the determination result, post-conversion difference data 194 (difference data using a special Move instruction and a Skip instruction) is generated and stored in the data storage unit 190.

  The difference data output unit 140 compares the data size of the pre-conversion difference data 193 stored in the data storage unit 190 with the data size of the post-conversion difference data 194, and outputs the smaller data size as difference data.

  When the update pattern in FIG. 1 is an update from the old data 192 to the new data 191, the difference data in FIG. 9 corresponds to the pre-conversion difference data 193, and the difference data in FIG. 10 corresponds to the post-conversion difference data 194. The difference data 194 having a smaller size is applied to the difference data.

FIG. 16 is a flowchart showing a process flow of the difference data generation apparatus 100 according to the first embodiment.
As illustrated in FIG. 16, the difference data generation device 100 performs the following processing.

  First, the first difference data generation unit 120 inputs the new data 191 and the old data 192 stored in the data storage unit 190, and based on the input new data 191 and old data 192, the difference data 193 before conversion is obtained. The data is generated and stored in the data storage unit 190 (S101).

A conventional difference extraction process can be used for the generation process of the pre-conversion difference data 193 performed by the first difference data generation unit 120.
For example, Walter F.M. The pre-conversion difference data 193 is generated by the process used in the paper “The String-to-String Correction Problem with Block Moves” by Tichy.

  Next, the second difference data generation unit 130 receives the pre-conversion difference data 193 stored in the data storage unit 190, generates post-conversion difference data 194 based on the input pre-conversion difference data 193, and the data storage unit 190 (S102).

FIG. 17 is a flowchart illustrating a process flow of the differential data second generation unit 130 in the first embodiment.
The post-conversion difference data 194 generation process of the difference data second generation unit 130 in S102 will be described with reference to FIG.
First, the offset information of all Move instructions is extracted from the pre-conversion difference data 193 (S201).
Next, when there are a plurality of Move instructions having the same offset, a special Move instruction is inserted at a position immediately before the first Move instruction among these Move instructions.
At this time, the move size of the special Move instruction is set to the difference between the end address of the data to be moved by the last Move instruction and the start address of the data to be moved by the first Move instruction.
Also, the offset of the special Move instruction is made the same as the offset of the Move instruction.
Next, all Move instructions having the same offset are replaced with Skip instructions (S203).
At this time, the Skip size is made the same as the Move size of the replacement target Move instruction.
In this way, the difference data 406 can be converted into difference data using a special Move instruction.

An operation example of the converted difference data 194 generation process of the second difference data generation unit 130 will be described with reference to FIGS. 1, 9, and 10.
In S201, by extracting the offset information of the Move instruction from the pre-conversion difference data 193 shown in FIG. 9, it is understood that there are four Move instructions with the offset “+100”.
These four Move instructions correspond to A ′, C ′, E ′, and G ′ in FIG.
In S202, a special Move instruction “Move ′ + 100 440” is inserted immediately before the “Move +100 100” instruction at the head of these Move instructions.
In S203, the converted difference data 194 is generated by replacing each Move instruction with a Skip instruction.
The generated difference data 194 after conversion is the difference data shown in FIG.

  In FIG. 16, the difference data output unit 140 receives the pre-conversion difference data 193 and the post-conversion difference data 194 stored in the data storage unit 190, and sets the sizes of the post-conversion difference data 194 and the pre-conversion difference data 193. Compare. If the size of the converted difference data 194 is smaller, the converted difference data 194 is output as difference data. If the size of the pre-conversion difference data 193 is smaller, the pre-conversion difference data 193 is output as difference data (S103).

Note that, in the post-conversion difference data 194 generation process of the difference data second generation unit 130, when there are a plurality of Move instructions with the same offset, all the Move instructions corresponding to the above are grouped together with a special Move instruction. It was.
However, only a part of the Move instructions corresponding to the above may be collected by a special Move instruction.
Furthermore, the special Move instruction may be applied to various combinations of the Move instructions corresponding to the above, and the combination having the smallest difference data size may be determined and the special Move instruction may be inserted.

  By having the above configuration and processing, the differential data generation apparatus 100 can express the differential data small in an update pattern that cannot be expressed in a small size by the conventional technology.

  Further, the difference data generation unit 110 includes the difference data first generation unit 120 and the difference data second generation unit 130, so that the pre-conversion difference data 193 and the post-conversion difference data 194 can be generated. By providing the unit 140, difference data having a smaller size can be selected.

Embodiment 2. FIG.
In the second embodiment, parts different from the first embodiment will be described, and the other parts are the same as those in the first embodiment.
FIG. 18 is an internal configuration diagram of the difference data generation device 100 according to the second embodiment.
In FIG. 18, the data storage unit 190 indicates old data arrangement information data 197 that indicates the position of partial data that is data of each part of the old data 192 and the position of partial data that is data of each part of the new data 191. New data arrangement information data 196 is stored.
The difference data generation unit 110 includes a partial data association unit 150 and a difference extraction unit 160.

  The partial data association unit 150 inputs the new data arrangement information data 196 and the old data arrangement information data 197 stored in the data storage unit 190, and the partial data of the new data 191 indicated by the new data arrangement information data 196 Then, partial data association information data 198 in which the partial data of the old data 192 indicated in the old data arrangement information data 197 is associated is generated and stored in the data storage unit 190.

  The difference extraction unit 160 generates difference data 195 using a special Move instruction and a Skip instruction based on the partial data association information data 198, the old data 192, and the new data 191 stored in the data storage unit 190. .

FIG. 19 is a diagram showing old and new data and arrangement information data in the second embodiment.
The old data 192 is composed of four partial data A, B, C, and D. This information is described in the old data arrangement information data 197.
The row “A 0 500” of the old data arrangement information data 197 indicates that the partial data A is in the range of the address 0 to the size 500.
Similarly, partial data A, B, C, and D also exist in the new data 191.
In the example of FIG. 19, the new data arrangement information data 196 has the partial data A size increased by 200 compared to the old data arrangement information data 197, the partial data B start address has increased by 200, It can be seen that the start address of data C is increased by 200 and the size is increased by 100, and the start address of partial data D is increased by 300 and the size is decreased by 300.

  In general, there is often a one-to-one correspondence between partial data between old and new data, but partial data that did not exist in the old data 192 exists in the new data 191 or exists in the old data 192. In some cases, the data does not exist in the new data 191.

As the arrangement information data of the old data 192 and the new data 191, when the old and new data is a binary image of a program, a link map file output when the program is linked can be used. This link map file is a description of arrangement information in the program.
Further, the arrangement information does not necessarily have to be provided as information different from the data. If the data includes arrangement information in the data, the data itself can be used as the arrangement information. Data including arrangement information in the data includes, for example, DLL (Dynamic Link Library).

The partial data refers to a section in a program link, for example.
It is also possible to regard that the old data 192 and the new data 191 are each composed of only one partial data. In this case, arrangement information data is not necessary.

FIG. 20 is a diagram showing partial data association information data 198 in the second embodiment.
The partial data association unit 150 associates the partial data of the old data 192 and the new data 191 based on the old data arrangement information data 197 and the new data arrangement information data 196, and the partial data as shown in FIG. The association information data 198 is generated.
In FIG. 20, the partial data association information data 198 correlates the offsets and sizes of the partial data A, the partial data B, the partial data C, and the partial data D of the old data 192 and the new data 191. Yes. Further, the same size flag is set for the partial data B having the same size.

A method for generating difference data using the partial data association information data 198 will be described below.
In the first method, if the sizes of the associated partial data are the same, the entire area is expressed by a special Move instruction, and then compared in order from the beginning of the old partial data and the beginning of the new partial data. The Skip instruction is assigned to the matching part, and the Add instruction or the Move instruction designating the data of the different part of the old data 192 is assigned to the non-matching part.

The first method will be described with reference to FIG.
Assume that the size of the associated partial data of the old data 192 (data positioned between p1 and p6) and the partial data of the new data 191 (data positioned between q1 and q6) are the same.
In this case, first, a special Move instruction is generated with the sizes from p1 to p6 and q1 to q6 and the offsets of p1 and q1 as the special Move size and special Move offset, respectively.
Then, pay attention to p1 of the old data 192 and q1 of the new data 191.
Next, the old data 192 and the new data 191 are compared by 1 unit (for example, 1 byte) from p1 and q1, respectively.
When p2 and q2 are reached and different positions are found between the old data 192 and the new data 191, first, a portion between q1 and q2 of the new data 191 is represented by a Skip instruction.
Next, the old data 192 and the new data 191 are compared one by one from p2 and q2, and a match between the new and old data 192 is found again at p3 and q3.
At this point, difference data for the range from p2 to p3 is generated.
Here, as a method of generating difference data for the range from p2 to p3, whether the part from p2 to p3 of the new data 191 is expressed by the Add instruction, or a matching part is found from the old data 192 and expressed by the Move instruction Alternatively, a method of expressing by a combination of an Add instruction and a Move instruction can be used.
Then, the same processing is continued again from p3 and q3, and when the p6 and q6 are finally reached, a Skip instruction is output and the processing is terminated.

FIG. 22 is a flowchart illustrating a process flow of the difference extraction unit 160 according to the second embodiment.
The process flow of the first difference data generation method will be described with reference to FIG.
The difference extraction unit 160 refers to the same size flag of the partial data association information data 198 stored in the data storage unit 190, searches for the corresponding partial data of the same size in the old data 192 and the new data 191, and performs a search. The following processing is performed on the partial data thus generated to generate a special Move instruction and a Skip instruction.

First, a special Move instruction that sets the size of the partial data of the retrieved old data 192 and new data 191 and the relative address of the partial data of the old data 192 relative to the partial data of the new data 191 as a special Move size and special Move offset. Generate (S201).
Next, for each unprocessed partial data, one byte is acquired from the partial data of the old data 192 and the partial data of the new data 191 (S203).
Next, 1 byte of the acquired old data 192 and 1 byte of the new data 191 are compared (S204).
As a result of comparing the acquired 1 byte of the old data 192 and 1 byte of the new data 191, if the values are the same, acquisition of 1 byte at a time from the partial data of the old data 192 and the partial data of the new data 191 (S203) ) And comparison (S204) are repeated until it is determined that there is no unprocessed data (S202) or the acquired 1 byte is different (S204).
As a result of comparing 1 byte of the acquired old data 192 and 1 byte of the new data 191, if the values are different, the acquired partial data of the old data 192 and the partial data of the new data 191 are the same. A Skip instruction that sets the size of the same part to the Skip size is generated (S205).

  Further, as a result of comparing 1 byte of the acquired old data 192 and 1 byte of the new data 191, if it is determined that there is no unprocessed partial data after the same value (S202), the same as S205 A Skip instruction that sets the size of the same part to the Skip size is generated, and the process ends (S210).

After generating the Skip instruction (S205), the presence / absence of unprocessed partial data is determined (S206).
If it is determined that there is unprocessed partial data, 1 byte is acquired from the partial data of the old data 192 and the partial data of the new data 191 for the unprocessed partial data (S207).
Next, 1 byte of the acquired old data 192 and 1 byte of the new data 191 are compared (S208).
As a result of comparing the acquired 1 byte of the old data 192 and 1 byte of the new data 191, if the values are different, acquisition of 1 byte at a time from the partial data of the old data 192 and the partial data of the new data 191 (S207 ) And comparison (S208) are repeated until it is determined that there is no unprocessed data (S206), or the acquired 1 byte indicates the same value (S208).
As a result of comparing 1 byte of the acquired old data 192 and 1 byte of the new data 191, if the values are the same, the difference between the acquired partial data of the old data 192 and the partial data of the new data 191 is added. An instruction and a Move instruction are generated. For example, an Add instruction is generated with the size of the different part and the new data 191 of the different part as Add size and Add data, and the process is repeated from S202 (S209).

  Further, as a result of comparing 1 byte of the acquired old data 192 and 1 byte of the new data 191, if it is determined that there is no unprocessed partial data after different values (S206), the same as S209 An Add instruction and a Move instruction are generated, and the process ends (S211).

In the above description, before the special Move instruction is generated (S201), the old data 192 and the new data 191 are sequentially compared from the beginning and the first matching portion is set as the beginning of the target range of the special Move instruction. In addition, a process may be added in which comparison is performed sequentially from the end of the new data 191 toward the top and the first matching portion is set as the end of the target range of the special Move instruction.
As a result, useless copying of the area can be prevented.

Further, the difference data may be extracted by a conventional method that does not use a special Move instruction, the difference data sizes are compared, and the smaller one may be output as the difference data for the partial data.
For that purpose, the difference data generation device 100 according to the second embodiment may include the first difference data generation unit 120 and the difference data output unit 140 described in the first embodiment.
Thereby, the difference data generation device 100 can output difference data having a smaller size.

  In the second embodiment, the difference data generation apparatus 100 receives the old data arrangement information data 197 and the new data arrangement information data 196 as input, and performs the partial data of the old data and the new data having the same size. It has been explained that difference data using a special Move instruction and a Skip instruction can be generated.

Embodiment 3 FIG.
In the third embodiment, a second generation method of difference data using the partial data association information data 198 will be described.
In the third embodiment, parts different from the above embodiment will be described, and the other parts are the same as those in the above embodiment.
FIG. 23 is an internal configuration diagram of the difference data generation device 100 according to the third embodiment.
Regarding the internal configuration of the difference data generation device 100, a configuration different from FIG. 15 of the first embodiment and FIG. 18 of the second embodiment will be described based on FIG. 23, and the other configurations are the same as those of FIG. 15 and FIG. Suppose that

The first difference data generation unit 120 includes an LCS (longest common subsequence) extraction unit 121.
Further, the first difference data generation unit 120 receives the partial data association information data 198, the new data 191 and the old data 192 as input, and obtains the pre-conversion difference data 193 which is difference data not using the special Move instruction and the Skip instruction. Output.
The differential data second generation unit 130 receives the partial data association information data 198 and the pre-conversion difference data 193, and outputs post-conversion difference data 194 using a special Move instruction and a Skip instruction.

The LCS extraction unit 121 extracts the longest common partial sequence (LCS) from the partial data corresponding to the old data 192 and the new data 191.
For the extraction of LCS, an efficient algorithm such as “EW Myers,“ An O (ND) difference algorithm and its variations ”, Algorithmmixa, 1 (1986), pp251-266” is known as a conventional technique. These conventional techniques can be used.
The LCS has a feature that, when copying from the old data 192 to the new data 191, a copy in which the order in the old data 192 and the order in the new data 191 are switched is not detected.
In the example of FIG. 6, the copy from J to E ′ and the copy from G to G ′ are not detected at the same time, and the copy from E to E ′ and from G to G ′ can be detected at the same time.
Due to this feature, in the case where a position shift occurs in the update from the old data 192 to the new data 191 as shown in FIG. 1 or FIG. It can be said that the probability that a pattern that can be expressed, that is, a pattern in which a Move instruction with the same offset is continuous can be detected is higher than that of a normal differential data extraction method that can simultaneously extract J to E ′ and G to G ′. Therefore, by extracting LCS, when there is a possibility that the difference data can be expressed small, the difference data is accurately expressed small, and more effective difference data is generated using the special Move instruction and the Skip instruction. can do.

After obtaining the LCS, the first difference data generation unit 120 generates the pre-conversion difference data 193 by expressing the partial sequence determined as the LCS with the Move instruction and expressing the other portion with the Add instruction.
In the example of FIG. 24, A and A ′, B and B ′... G and G ′ are determined as common parts, each is represented by a Move instruction, and the remaining part is represented by an Add instruction.

Next, the process performed by the differential data second generation unit 130 to collect Move instructions with the same offset and replace them with one special Move instruction will be described.
As an example of the process, as described in the first embodiment, a process of expressing the move instruction having the same offset from the beginning to the end with one special Move instruction can be considered.
Also, the difference data is searched from the beginning, the offset of the first move instruction found is stored, and the range until the move instruction that is not the same offset is found or until the end of the partial data that is the comparison range is obtained. An operation expressed by a special Move instruction is also conceivable.
At this time, the Add instruction is skipped.

The latter process will be described with reference to FIG.
The Move instruction for A ′ of the new data 191 is first read and the offset information is stored.
Following the Move instruction for A 'is the Add instruction, which is ignored.
Next, the Move instruction for B ′ is found, and the offset information is the same as the offset information of the Move instruction for A ′ described above. Therefore, the Move instruction for B ′ is also set as a range candidate for the special Move instruction.
Similarly, the Move instruction for C ′ and D ′ has the same offset, and is therefore a range candidate for the special Move instruction.
A Move instruction for E ′ is found across the Add instruction, but this offset information is different from the offset information for A ′.
For this reason, the target of the previous Move instruction, that is, D ′, is output as the target range of the special Move instruction.
Also, since different offset information has been found, after the Move instruction for E ′, the process proceeds as offset information for comparing the offset information of the Move instruction for E ′.
As a result, the offset information of the Move instruction for E ′, F ′, and G ′ is the same, and since G ′ is the end of the partial data, the range from E ′ to G ′ is set as the target range of the special Move instruction.

Next, the operation of the differential data second generation unit 130 will be described.
In the example of FIG. 24, a special Move instruction is inserted at the head of the difference data representing the range from A ′ to D ′ and the range from E ′ to G ′, and the Move instruction is replaced with a Skip instruction.
Also, the Add instruction is directly expressed as an Add instruction, or a matching portion is searched from the old data 192 for the range of the new data 191 corresponding to the Add instruction and replaced with the Move instruction.
For the range between D ′ and E ′, the Add instruction is output as it is, or a matching portion is searched from the entire old data 192 and expressed by the Move instruction, and converted difference data 194 is generated.

The difference data output unit 140 compares the sizes of the pre-conversion difference data 193 and the post-conversion difference data 194, and outputs the smaller one as difference data.
Thereby, smaller difference data can be selected.

FIG. 25 is a flowchart illustrating a process flow of the first difference data generation unit 120 according to the third embodiment.
FIG. 26 is a flowchart showing a process flow of the differential data second generation unit 130 in the third embodiment.
The flow of processing between the difference data first generation unit 120 and the difference data second generation unit 130 described above will be described with reference to FIGS. 25 and 26.

In FIG. 25, the first difference data generation unit 120 performs the following process to generate pre-conversion difference data 193.
The corresponding partial data is acquired from the old data 192 and the new data 191 with reference to the partial data association information data 198 (S302).
The LCS extraction unit 121 is activated and LCS is extracted from the acquired partial data (S303).
For the extracted LCS, a Move instruction is generated in which the length of the LCS and the value indicating the relative position of the LCS old data 192 relative to the new data 191 are set to the Move size and the Move offset (S304).
The size of the extracted LCS is determined (S305).
If the size of the extracted LCS is equal to or greater than a certain value, a common partial sequence next to the extracted LCS is extracted for the same partial data (S303), and a Move instruction is generated for the extracted common partial sequence (S304). )I do. The fixed value for determining the size of the LCS is arbitrary. For example, the instruction code size is smaller when represented by the Move instruction than when represented by the Add instruction. In the case of the instruction code format shown in FIG. 8, it is determined whether the LCS size is 4 bytes or more.
If the size of the extracted LCS is less than a certain value, an Add instruction is generated for the portion that has not been extracted as the LCS (S306).
After generating the Add instruction (S306), the partial data association information data 198 is referred to, and new partial data is acquired from the old data 192 and the new data 191 (S302), the LCS is extracted (S303), and the Move instruction Generation (S304) and generation of an Add instruction (S306) are performed.
If there is no new partial data as a result of referring to the partial data association information data 198, the process is terminated (S301).

Next, in FIG. 26, the difference data second generation unit 130 performs the following processing to generate converted difference data 194.
An instruction code is acquired from the converted difference data 194 (S402).
The acquired instruction code is determined (S403).
When the acquired instruction code is an Add instruction, the next instruction code is acquired (S402), and the acquired instruction code is determined (S403).
If the acquired instruction code is a Move instruction, a Move offset is determined (S404).
When the Move offset of the acquired Move instruction is the same as the Move offset of the previous Move instruction acquired, the acquired Move instruction is replaced with a Skip instruction (S405).
After replacing the Move instruction with the Skip instruction (S405), the next instruction code is acquired (S402), the acquired instruction code is determined (S403), and the process is repeated.
If the Move offset of the acquired Move instruction is not the same as the Move offset of the immediately preceding Move instruction, a special Move instruction is inserted (S406).
Also, the Move offset of the Move instruction replaced with the Skip instruction is set in the Move offset of the previous special Move instruction.
In addition, the total size of the Skip size of the Skip instruction replaced from the Move instruction and the Add size of the Add instruction sandwiched between the Skip instructions is set as the Move size of the previous special Move instruction.
After inserting the special Move instruction (S406), the next instruction code is acquired (S402), the acquired instruction code is determined (S403), and the process is repeated.
If all instruction codes are processed and it is determined that there is no instruction code to be acquired, the process ends (S401).

By having the above configuration and processing, the differential data generating apparatus 100 can express the differential data small in an update pattern that cannot be expressed in a small size by the conventional technique.
Further, when there is a possibility that the difference data can be expressed in a small size, the difference data can be accurately expressed in a small size.

Embodiment 4 FIG.
In the fourth embodiment, a third generation method of difference data using the partial data association information data 198 will be described.
In the fourth embodiment, parts different from the above embodiment will be described, and the other parts are the same as those in the above embodiment.
FIG. 27 is an internal configuration diagram of the difference data generation device 100 according to the fourth embodiment.
Regarding the internal configuration of the difference data generation device 100, a configuration different from FIG. 15 of the first embodiment, FIG. 18 of the second embodiment and FIG. 23 of the third embodiment will be described based on FIG. The configuration is the same as in FIGS. 15, 18 and 23.

The difference data generation unit 110 includes a difference LCS extraction unit 170.
The differential LCS extraction unit 170 includes an LCS extraction unit 171.
The differential LCS extraction unit 170 receives the partial data association information data 198, the new data 191 and the old data 192, and generates differential data 195.
The LCS extraction unit 171 performs LCS extraction in the same manner as the LCS extraction unit 121 of the third embodiment.

FIG. 28 is a diagram showing partial data association information data 198 in the fourth embodiment.
In the fourth embodiment, the partial data association unit 150 generates partial data association information data 198 as shown in FIG.
The partial data association information data 198 has a partial combined data flag item. In FIG. 19, the partial data A, B, C, and D of the old data 192 are combined with the partial data A, B, and new data 191 of FIG. The data obtained by combining C and D has the same size.

FIG. 29 is a flowchart showing a process flow of the differential LCS extraction unit 170 in the fourth embodiment.
The difference data generation process of the difference LCS extraction unit 170 in the fourth embodiment will be described with reference to FIG.

One piece of data is acquired from the partial data association information data 198 as shown in FIG. 28, and it is determined whether the partial data is included in the partial combined data (S502).
If the partial data is included in the partial combined data, a special Move instruction is generated that sets the offset and total size of the partial data included in the combined partial data as a special Move offset and a special Move size (S504).
An LCS is extracted for each partial data included in the combined partial data, and a Skip instruction and an Add instruction are generated (S505 to S510).
The processing of S505 to S510 is the same as the processing S301 to S306 of the difference data first generation unit 120 shown in FIG. 25 of the third embodiment, and the difference LCS extraction unit 170 uses the Move instruction for the extracted LCS. Instead, a Skip instruction is generated (S506).
If all partial data included in the combined partial data are processed and it is determined that there is no partial data to be acquired (S505), the next combined partial data is acquired, a special Move instruction is generated, and the process is repeated.
When the partial data is not included in the partial combined data, the processing shown in FIG. 22 of the second embodiment and the processes shown in FIGS. 25 and 26 of the third embodiment is performed, and the difference with respect to the partial data not included in the partial combined data Data is generated (S503).
If all the partial data indicated in the partial data association information data 198 has been processed, the process is terminated (S501).

In the above embodiment, the following has been described.
In the difference data generation apparatus that extracts difference data for upgrading from the old data 192 to the new data 191 with respect to the old and new two data, as the difference data, data from a part or all of the old data 192 is obtained. Zero or more Move instructions that mean to move and copy to the new data 191; zero or more Add instructions that mean to add the data described in the differential data to the new data 191; Zero or more special Moves, which means that the rewrite pointer for the new data 191 is moved to the beginning of the copy data after the data is moved from a part or all of the old data 192 and copied to the new data 191. This means that the instruction and the rewrite pointer for the new data 191 are moved forward by the specified length. Been described difference data generator 100 for generating a composed difference data at zero or more Skip instructions that.

  Further, the difference data generation apparatus 100 includes a difference extraction processing means for extracting difference data for upgrading from the old data 192 to the new data 191 in a format not including the special Move instruction, and a format not including the special Move instruction. It has been described that difference data conversion means for finding a portion where the difference data size is smaller when expressed with the special Move instruction for the difference data and replacing it with an expression including the special Move instruction.

  Further, the difference data generation device 100 associates the partial data of the old and new data 192 with each other based on the arrangement information of the old and new data 192 included in the new and old data 192 or the arrangement information data provided accompanying the old and new data 192. A data extraction unit that compares the partial data of the old and new data 192 associated by the region association function and generates difference data, and the difference extraction unit is associated In the case where the data lengths of the partial data are the same, it has been described that a special Move instruction indicating a copy of the partial data area is used as a component of the difference data.

  Further, when the data length of the associated partial data is the same, the difference extraction processing unit compares the same offsets from the top of the new and old data 192, and from the first matching position to the last matching position. It was explained that the space is expressed by a special Move instruction.

  The difference extraction processing means obtains the longest common partial sequence for the associated partial data, the longest common partial sequence calculating means for expressing the obtained longest common partial sequence as difference data, and the longest common partial sequence calculating means Copy range determination means for selecting zero or more ranges to be expressed by the special Move instruction from the generated difference data, and the range determined to be expressed by the special Move instruction by the copy range determination means is the difference data using the special Move instruction. It has been explained that it is composed of differential data generating means for replacement.

  The difference data generating means replaces the range determined to be expressed by the special Move instruction by the copy range determining means with the difference data using the special Move instruction, and newly generates normal difference data for the other range. The difference data generating means has been described.

  The difference extraction processing means generates two types of difference data including the special Move instruction as a component and difference data not including the special Move instruction as a component, and outputs the smaller difference data as the difference data. I explained that.

  The difference extraction processing means performs difference extraction even in a pattern in which the special Move instruction is not used for the range of the new data 191 corresponding to each special Move instruction of the difference data generated so as to include the special Move instruction as a component. The difference data of the range is compared with the difference data using the special Move instruction and the difference data not using the difference data. When the difference data not using the special Move instruction is smaller in size, the range of the new data 191 It has been described that the difference data with respect to is replaced with difference data that does not use the special Move instruction.

The figure which shows the old data 192 and the new data 191. The figure which shows the difference data by a prior art example. The figure which shows the difference data by a prior art example. The figure which shows the old data 192 and the new data 191. The figure which shows the difference data by a prior art example. The figure which shows the old data 192 and the new data 191. The figure which shows the difference data by a prior art example. FIG. 3 shows an instruction code format of difference data in the first embodiment. The figure which shows the difference data by a prior art example. FIG. 4 shows difference data in the first embodiment. The figure which shows the difference data by a prior art example. FIG. 4 shows difference data in the first embodiment. FIG. 3 is a diagram illustrating an appearance of a difference data generation device 100 according to the first embodiment. FIG. 2 is a hardware configuration diagram of the difference data generation device 100 according to the first embodiment. FIG. 2 is an internal configuration diagram of a difference data generation device 100 according to the first embodiment. 3 is a flowchart showing a process flow of the differential data generation device 100 according to the first embodiment. 5 is a flowchart showing a flow of processing of a differential data second generation unit 130 in the first embodiment. The internal block diagram of the difference data generation apparatus 100 in Embodiment 2. FIG. The figure which shows the old and new data and arrangement | positioning information data in Embodiment 2. FIG. The figure which shows the partial data matching information data 198 in Embodiment 2. FIG. FIG. 6 shows old data 192 and new data 191 in the second embodiment. 9 is a flowchart showing a process flow of a difference extraction unit 160 in the second embodiment. The internal block diagram of the difference data generation apparatus 100 in Embodiment 3. FIG. FIG. 11 shows old data 192 and new data 191 in the third embodiment. 10 is a flowchart showing a flow of processing of a difference data first generation unit 120 according to Embodiment 3. 9 is a flowchart showing a flow of processing of a difference data second generation unit in Embodiment 3. The internal block diagram of the difference data generation apparatus 100 in Embodiment 4. FIG. The figure which shows the partial data matching information data 198 in Embodiment 4. FIG. 10 is a flowchart showing a process flow of a differential LCS extraction unit 170 in the fourth embodiment.

Explanation of symbols

  100 differential data generation device, 110 differential data generation unit, 120 differential data first generation unit, 121 LCS extraction unit, 130 differential data second generation unit, 140 differential data output unit, 150 partial data association unit, 160 differential extraction unit , 170 Difference LCS extraction unit, 171 LCS extraction unit, 190 Data storage unit, 191 New data, 192 Old data, 193 Difference data before conversion, 194 Difference data after conversion, 195 Difference data, 196 New data arrangement information data, 197 Old Data arrangement information data, 198 partial data association information data, 901 CRT display device, 902 K / B, 903 mouse, 904 FDD, 905 CDD, 906 printer device, 907 scanner device, 910 system unit, 911 CPU, 912 bus, 913 ROM, 914 RAM, 915 communication board, 920 magnetic disk unit, 921 OS, 922 window system, 923 program group, 924 file group, 931 telephone, 932 FAX machine, 940 Internet, 941 Web server, 942 LAN.

Claims (10)

In order to move from old data to new data, includes information for controlling the old data pointer indicating the data position of the old data and the new data pointer indicating the data position of the new data, and an instruction code relating to the information of the data to be transferred In the difference data generation device that generates the difference data,
A data storage unit for storing old data and new data;
Read the old data and new data stored in the data storage unit,
Indicates the position indicated by the old data pointer and the copy size, copies the data at the position indicated by the old data pointer by the copy size from the position indicated by the new data pointer, and moves the position moved by the copy size from the position indicated by the new data pointer. Determining whether to include in the difference data a first Move instruction code indicating setting a value to be indicated in the new data pointer;
Indicates additional data and additional data size, indicates that additional data is added from the position indicated by the new data pointer, and a value indicating the position moved by the additional data size is set to the new data pointer. Determining whether to include the Add instruction code in the difference data;
A second Move instruction indicating the position indicated by the old data pointer and the copy size, copying the data at the position indicated by the old data pointer by the copy size from the position indicated by the new data pointer, and not updating the value of the new data pointer Whether to include the code in the difference data;
Indicates the pointer update size, and determines whether or not to include in the difference data a Skip instruction code indicating that a value indicating the position moved by the pointer update size from the position indicated by the new data pointer is set in the new data pointer. A difference data generation apparatus comprising: a difference data generation unit that stores and generates difference data based on a determination result and stores the difference data in a storage unit. The difference data generation unit
Based on the old data and the new data stored in the data storage unit, a determination is made as to whether the first Move instruction code is included in the difference data, and a determination is made as to whether the Add instruction code is included in the difference data. The second Move instruction code And a difference data first generation unit for generating difference data not including the Skip instruction code,
The difference data generated by the difference data first generation unit is input, and based on the input difference data, whether to include the second Move instruction code in the difference data and whether to include the Skip instruction code in the difference data are determined. The difference data generation apparatus according to claim 1, further comprising a difference data second generation unit configured to perform difference data generation based on a determination result. The data storage unit further includes:
Old data arrangement information data indicating the position of partial data that is data of each part of the old data,
Storing new data arrangement information data indicating the position of the partial data of the new data corresponding to the partial data of the old data,
The difference data generation unit
In the case where the old data partial data and the new data partial data corresponding to the old data arrangement information data and the new data arrangement information data stored in the data storage unit have the same size, the second Move instruction code is converted into the difference data. 2. The difference according to claim 1, further comprising: generating difference data including a second Move instruction code that determines to include and copies the corresponding partial data of the old data to the position of the corresponding partial data of the new data. Data generator. The data storage unit is
Old data arrangement information data indicating the position of partial data that is data of each part of the old data,
Storing new data arrangement information data indicating the position of the partial data of the new data corresponding to the partial data of the old data,
The difference data generation unit
In the case where the old data partial data and the new data partial data corresponding to the old data arrangement information data and the new data arrangement information data stored in the data storage unit have the same size, the second Move instruction code is converted into the difference data. It is determined to include, the common partial sequence of the corresponding partial data of the old data and the corresponding partial data of the new data is searched, and from the first common partial sequence to the final common partial sequence of the partial data of the old data 2. The difference data according to claim 1, further comprising: generating difference data including a second Move instruction code indicating that copying is performed from the first common partial sequence to the position of the final common partial sequence among the partial data of the new data. Data generator. The difference data generation unit
Based on the old data and the new data stored in the data storage unit, a determination is made as to whether the first Move instruction code is included in the difference data, and a determination is made as to whether the Add instruction code is included in the difference data. The second Move instruction code And a difference data first generation unit for generating difference data not including the Skip instruction code,
In the case where the old data partial data and the new data partial data corresponding to the old data arrangement information data and the new data arrangement information data stored in the data storage unit have the same size, the second Move instruction code is converted into the difference data. A difference data second generation unit that generates difference data including a second Move instruction code that determines to include and copies the corresponding partial data of the old data to the position of the corresponding partial data of the new data; The difference data output unit that inputs the difference data generated by the generation unit and the difference data generated by the difference data second generation unit, compares the data size of the input difference data, and outputs the smaller data size as the difference data The difference data generation device according to claim 3, further comprising: The data storage unit is
Old data arrangement information data indicating the position of partial data that is data of each part of the old data,
Storing new data arrangement information data indicating the position of the partial data of the new data corresponding to the partial data of the old data,
The difference data generation unit
A longest common subsequence search unit that searches for the longest common subsequence of the partial data of the old data and the partial data of the new data corresponding to the old data arrangement information data and the new data arrangement information data stored in the data storage unit; ,
Based on the old data and new data stored in the data storage unit, a determination is made as to whether the first Move instruction code is included in the difference data and a determination is made as to whether the Add instruction code is included in the difference data. First difference data for generating difference data including a first Move instruction code indicating that the longest common partial sequence searched by the column search unit is copied from the old data to the new data, and not including the second Move instruction code and the Skip instruction code A generator,
The difference data generated by the difference data first generation unit is input, and based on the input difference data, whether to include the second Move instruction code in the difference data and whether to include the Skip instruction code in the difference data are determined. The difference data generation apparatus according to claim 1, further comprising a difference data second generation unit configured to perform difference data generation based on a determination result. The difference data first generation unit includes:
If it is determined that the first Move instruction code is included in the difference data, the difference data including the first Move instruction code that represents the position indicated by the old data pointer as a relative value with respect to the position indicated by the new data pointer is generated.
The difference data second generation unit
The difference data generated by the difference data first generation unit is input, the first Move instruction code included in the input difference data is extracted, and the new data pointer indicated by the old data pointer is extracted from the extracted first Move instruction code. A plurality of first Move instruction codes having the same relative value are acquired, and the plurality of acquired first Move instruction codes are converted into at least one of a second Move instruction code and a Skip instruction code to generate difference data. The difference data generation device according to claim 2 or 6. The difference data generation unit further includes:
The difference data generated by the first difference data generation unit and the difference data generated by the second difference data generation unit are input, the data sizes of the input difference data are compared, and the smaller data size is set as difference data. The differential data generation apparatus according to claim 2, further comprising a differential data output unit for outputting. In order to move from old data to new data, includes information for controlling the old data pointer indicating the data position of the old data and the new data pointer indicating the data position of the new data, and an instruction code relating to the information of the data to be transferred In the difference data generation method of the difference data generation device that generates the difference data,
A data storage step of storing old data and new data in the storage unit;
Read the old data and new data stored in the data storage process,
Indicates the position indicated by the old data pointer and the copy size, copies the data at the position indicated by the old data pointer by the copy size from the position indicated by the new data pointer, and moves the position moved by the copy size from the position indicated by the new data pointer. Determining whether to include in the difference data a first Move instruction code indicating setting a value to be indicated in the new data pointer;
Indicates additional data and additional data size, indicates that additional data is added from the position indicated by the new data pointer, and a value indicating the position moved by the additional data size from the position indicated by the new data pointer is set in the new data pointer Determining whether to include the Add instruction code in the difference data;
A second Move instruction indicating the position indicated by the old data pointer and the copy size, copying the data at the position indicated by the old data pointer by the copy size from the position indicated by the new data pointer, and not updating the value of the new data pointer Whether to include the code in the difference data;
Indicates the pointer update size, and determines whether or not to include in the difference data a Skip instruction code indicating that a value indicating the position moved by the pointer update size from the position indicated by the new data pointer is set in the new data pointer. A difference data generation method comprising: storing and executing a difference data generation step of generating difference data based on a determination result and storing the difference data in a storage unit.   A difference data generation program for causing a computer to execute the difference data generation method according to claim 9.

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