JP4830558B2 - Structured document encoding apparatus and structured document decoding apparatus - Google Patents

Description

  The present invention relates to a structured document encoding apparatus and decoding apparatus thereof, and more particularly to a structured document encoding apparatus and decoding apparatus capable of referencing a similar external document as a part of the own document.

  Structured documents such as XML and SGML are used for various purposes such as communication standards because of their advantages such as flexibility and extensibility. As a communication standard that employs a structured document as a standard, SOAP (Simple Object Access Protocol) and the like are prominent.

  A structured document forms a tree structure with one element as a root. In general, each element includes an element name, an element value, an attribute name, an attribute value, a list of child elements, and the like. In this specification, a sub-tree consisting of a set of child elements with an arbitrary element as a parent in a tree structure is called a document part. It can be said that a structured document is a collection of a plurality of document parts.

  In particular, in communication using structured documents such as SOAP, the ability to compose one communication message by combining document parts defined by different document structure definitions is the reason for its high extensibility. . For example, in SOAP, a communication message consists of a header and a body. The body contains document parts specified for each application, and the header includes, for example, encryption and signature addition, destination information, session and transaction information, etc. It is possible to create a single communication message by freely combining any number of document parts defined by various communication control standards. In addition, when a large number of communications are performed between the same application systems, it is a feature in using structured documents for communication that usually a large number of similar structured documents are transmitted and received.

  However, since structured documents have a large document data size due to the redundancy of information expression methods, there are problems such as poor processing efficiency such as data generation and analysis, communication and storage. In order to solve this problem, several structured document processing apparatuses that compress the data size of a structured document have been proposed.

  One method is a method in which a structured document is not an original character string but another encoding method suitable for data size reduction is determined and used. In the present specification, this is referred to as a full-text holding binary representation method. For example, in Patent Document 1, the efficiency is improved by devising the format while having all information in one document. As shown in FIG. 28, in this full-text holding binary representation method, a structured document is input to the structured document encoding module and converted into an encoded document, and only the encoded document is input to the structured document decoding module. To restore the structured document. Such a full-text-retained binary representation method only eliminates the redundancy of the information that the structured document has in encoding, and the encoded document includes all the information necessary to restore the structured document. It is possible to decode an encoded document into a structured document without any other auxiliary information. In Patent Document 1, a document structure definition file is further used for verification of the encoded document, but this is used for verification and not for decoding. In this respect, the document structure definition file is used. Is different from the structure information external reference type described later, which is used for encoding.

  As another method, the structured document is not an original character string but another encoding method suitable for reducing the data size is determined and used. In addition, in addition to the encoded document, element names and attribute names are structured. Prepare a structure information encoding table that describes information related to the structure of the document. Instead of describing the document structure related information in each encoded document, describe only the reference to the corresponding information in the structure information encoding table. There is a method. In this specification, this is called a structure information external reference type binary representation method. For example, in Patent Document 2, the size of an encoded document is reduced by using such a structure information encoding table and devising a reference information encoding method. As shown in FIG. 29, this structure information external reference type binary representation method has a structure similar to the full-text holding type binary representation method. In addition, a structure information encoding table is prepared, and a structured document encoding module and structure are provided. The encoded document decoding module shares this, and the information regarding the structure is not described in the encoded document at the time of encoding. Instead, only the reference to the corresponding information in the structure information encoding table is described. The structured document is restored by using the coded document and the structure information coding table together. In this method, since the information defined by the document structure definition does not have to be described in each encoded document, the size compression effect can be enhanced as compared with the full-text holding binary representation method.

  As another method, there is a method of reducing transfer data size by generating difference information from a previous structured document and sending it, especially in communication. In the present specification, this is called a differential sending method. For example, in Patent Document 3, for the purpose of updating XML data on the client side, the structured document difference generation unit generates difference data from the old document to the new document, transfers it to the communication destination, and holds it on the receiving side. The new document is generated by applying the difference data to the old document. As shown in FIG. 30, in the difference sending method, the difference generation unit and the document update unit share one old structured document, and then use the difference data from the old document to the new document as a kind of encoded document. In this method, since only the difference between the old and new documents is used as transfer data regardless of the size of the original structured document, the compression effect can be enhanced if the difference between the old and new documents is small.

  As another method, although binary encoding is not performed, there is a method in which a reference to another structured document is described in the structured document, and the other document is taken into the own document as a document part. In a structured document, the document has a tree structure, but in this import, a reference is described in a certain node of the tree structure, so that it is given meaning as if the document referenced under that node is described. I can do it. In this specification, this is referred to as a document part taking-in method. For example, in Extensible Markup Language 1.0 (Extensible Markup Language (XML) 1.0), you can import other documents as part of your document using a notation called an external entity. . FIG. 31 shows an example of size compression using the document parts taking-in method. As a structured document, a document to be used as a component in advance is prepared and shared at the communication sender / receiver, and instead of sending the entire document during communication, the part that is equal to the prepared document in advance is sent in advance. If only a reference to a document is described, the structured document analysis module reads a pre-prepared structured document when there is a reference when the structured document is analyzed, and it looks as if it is a single document as a whole. Returns the result. In this method, if a large number of documents can be prepared for use as parts in advance, the compression ratio of the document size can be increased.

  As another method, for example, as seen in Patent Document 4, there is a method in which only one element in a structured document is focused and templated and difference calculation is performed for a combination of attributes of the element. In the present specification, this is called an internal element templating method. In the internal element templating method, a structured document is interpreted, whether or not the same element exists in the interpreted document is detected, and if the same element exists, the difference between the same elements is calculated and this calculation is performed. Each element is compressed and encoded based on the difference information.

JP 2004-302799 A JP 2005-215951 A JP 2003-256249 A JP 2005-284903 A

  As described above, several structured document processing apparatuses that compress the data size of a structured document have been proposed in the past, but each has the following problems.

  In the full-text binary representation method, the encoded document has the same information as the structured document, so arbitrary information can be added without prior adjustment between the communication transmitting and receiving devices, but all information is included in the encoded document. The compression effect of the size is low because it must be included.

  In the structure information external reference type binary representation method, the information such as element name and attribute name specified in the document structure definition does not need to be included in the encoded document, so the compression rate increases accordingly. Element information (information such as element parent / child relationships and references to character strings such as element names / attribute names) must be described in the same number as a structured document. For large documents, the compression effect is limited. . In addition, it is premised that the necessary structure information encoding table is shared between the communication transmitting and receiving apparatuses, and information based on the document structure definition not included in the structure information encoding table is added to the encoded document. I can't.

  The difference sending method can handle only the difference between two structured documents. For this reason, when the difference between two documents is large, for example, there are two structured documents a and b as the old document, and when one new structured document c that connects them is encoded, the difference data includes a and c. Or, only the difference between b and c can be taken, and as a result, the difference data will contain information corresponding to the document of b if it is the former and if it is the latter, Difference data becomes large.

  In the document part fetching method, only completely equal documents can be used as parts. For example, when a structured document including 100 elements is prepared in advance as a part, if the document part to be described in the reference structured document differs from the prepared document even in one element, that part is It cannot be used by the referrer and all information must be included in the referrer document. If the size of a document prepared as a part is reduced, the possibility that it can be used as a part increases probabilistically. However, in this case, a lot of reference information must be described in the reference source document. The size of the reference source document cannot be reduced too much.

  In the internal element templating method, since the same element repeatedly appears in one structured document, it is templated. Therefore, a high compression rate can be expected for a structured document including many identical elements. However, since there is no concept that refers to the same element in another structured document, compression cannot be achieved using an external structured document having the same or similar elements.

  As described above, in the conventional method, there is a limit to the effect of size compression particularly in processing of a structured document in which a plurality of independent document parts are combined and a large number of similar structured documents.

[Object of invention]
The object of the present invention is to obtain a high compression ratio and to freely add arbitrary information in the processing of a structured document composed of a plurality of document parts and the processing of a large number of similar documents. It is another object of the present invention to provide a structured document encoding apparatus and decoding apparatus thereof.

  The first structured document encoding apparatus according to the present invention includes an external document reference determining unit that searches for an external document having a document part similar to a document part included in the structured document to be encoded, and the searched external document. External document difference analysis means for calculating the difference between similar document parts of the structured document to be encoded and a document part similar to the document part of the external document among the document parts included in the structured document to be encoded Is provided with reference information to the document part of the external document and encoded document generation means for generating an encoded document encoded as difference information between the document parts.

  According to a second structured document encoding apparatus of the present invention, in the first structured document encoding apparatus, the encoded document generation unit includes reference information to the document part of the external document as reference information to the external document. It is characterized by being divided and encoded into reference information to document parts.

  A third structured document encoding device of the present invention is the first structured document encoding device, further comprising a document storage unit that stores an external document, and the external document reference determination unit is stored in the document storage unit. Of the external documents, an external document having a document part similar to the document part included in the structured document to be encoded is searched.

  According to a fourth structured document encoding apparatus of the present invention, in the third structured document encoding apparatus, a part or all of the structured document encoded by the encoded document generating unit is newly created as an external document. Document storage means for adding to the document storage unit is provided.

  The fifth structured document encoding apparatus of the present invention is the first structured document encoding apparatus, wherein the external document is encoded by the same method as the encoding method used by the encoded document generating means. It is characterized by being a document.

  According to a sixth structured document encoding apparatus of the present invention, in the fifth structured document encoding apparatus, the encoded document generation means encodes each element of the structured document as a part with an ID, and The encoding method that expresses the reference of the document with this ID is used, and the difference information between the document parts is the combination of the part IDs before and after replacing which part of the external document is replaced with which part. It is characterized by being.

  According to a seventh structured document encoding device of the present invention, in the sixth structured document encoding device, the encoded document generation means encodes the reference information to the external document including an ID conversion rule, In addition, when the ID of the component in the external document is described by the difference information, the ID obtained as a result of applying the conversion rule to the ID attached to the component in the external document is used.

  The eighth structured document encoding apparatus of the present invention is characterized in that, in the sixth structured document encoding apparatus, the parts before and after replacement are character strings.

  According to the first structured document decryption apparatus of the present invention, a document part similar to the document part of the external document among the document parts included in the structured document is between the reference information and the document part of the document part of the external document. An apparatus for decoding an encoded document encoded as difference information, an external document fetching unit for reading an external document indicated by the reference information, and an external document for rewriting the read external document based on the difference information Rewriting means, and structured document generating means for generating a structured document from an encoded document by replacing the portion encoded as the reference information and the difference information with the rewritten external document. .

  The second structured document decryption apparatus of the present invention is the first structured document decryption apparatus, wherein the reference information to the document part of the external document is the reference information to the external document and the document part in the encoded document. It is characterized by being divided and encoded into reference information.

  The third structured document decryption apparatus of the present invention is the first structured document decryption apparatus, further comprising a document storage unit for storing an external document, and the external document fetching unit refers to the reference from the document storage unit. An external document indicated by information is read.

  According to a fourth structured document decryption apparatus of the present invention, in the third structured document decryption apparatus, a part or all of the structured document decrypted by the structured document generation unit is newly created as an external document. Document storage means for adding to the document storage unit is provided.

  A fifth structured document decoding apparatus according to the present invention is characterized in that, in the first structured document decoding apparatus, the external document is an encoded document encoded by the same method as the encoded document. And

  The sixth structured document decryption apparatus of the present invention is the fifth structured document decryption apparatus, wherein the encoded document is encoded as a component with an ID attached to each element of the structured document and referenced between the elements. The difference information between document parts is expressed as a combination of parts ID before and after replacing which part of the external document is replaced by which part. The structured document generation means refers to the replacement in which the referenced ID is described in the difference information while referring to the ID and its parts described in the encoded document and the external document using the ID. If it is the previous ID, a structured document is generated by referring to the replaced ID instead.

  The seventh structured document decoding apparatus of the present invention is the sixth structured document decoding apparatus, wherein the encoded document is encoded by including an ID conversion rule in the reference information to the external document, and When describing the part ID in the external document with the difference information, the ID obtained as a result of applying the conversion rule to the ID attached to the part in the external document is used. The means is characterized in that a conversion process according to the conversion rule is performed on all IDs included in the read external document.

  An eighth structured document decryption apparatus according to the present invention is characterized in that, in the sixth structured document decryption apparatus, the parts before and after replacement are character strings.

  The structured document encoding method of the present invention is a method of encoding a structured document using a computer, and the computer has a document part similar to a document part included in a structured document to be encoded. A first step of searching for an external document; a second step of calculating a difference between similar document parts of the searched external document and a structured document to be encoded; and Among the document parts included in the structured document to be converted into a document part that is similar to the document part of the external document, generates an encoded document that is encoded as the reference information to the document part of the external document and the difference information between the document parts And a third step.

  According to the structured document decryption method of the present invention, among document parts included in a structured document, a document part similar to a document part of an external document is used as reference information for the document part of the external document and difference information between the document parts. A method for decoding an encoded document using a computer, wherein the computer reads an external document indicated by the reference information, and the computer reads the external document read by the computer. A second step of rewriting based on the difference information; and the computer generates a structured document from the encoded document by replacing the reference information and the portion encoded as the difference information with the rewritten external document. And 3 steps.

  The first data structure of the present invention includes one or more external document capture declaration data and one or more external part reference data, and the external document capture declaration data is an external indicating an external document to be captured in the own document. Document reference data is included, and the external part reference data includes reference destination data indicating which document part in the external document specified by the external document reference data is referred to, and the document part specified by the reference destination data. Difference information indicating which part is replaced with which part.

  According to a second data structure of the present invention, in the first data structure, the external document capture declaration data includes an ID conversion rule, and the reference destination data in the external part reference data is in an external document to be referenced. When an ID assigned to the document part in the external document is set by the conversion rule, and the ID of the part in the external document is described by the difference information, the part in the external document An ID obtained as a result of applying the conversion rule is set to the ID attached to.

"Action"
In the present invention, when the structured document is encoded, the external document reference determining unit examines an external encoded document including a document part similar to the document part of the structured document, and if there is an external document difference The analysis unit analyzes the difference between two similar document parts, and the encoded document generation unit uses the difference between the reference information to the external document and the reference destination as a description of the part in which the similar document exists in the encoded document. Record information. In addition, when decoding a structured document from an encoded document, if the reference information of the external document is included in the encoded document, the external document fetching means reads the part of the external document that is the reference destination, and rewrites the external document. The difference information is applied to the document part read by the means for rewriting, and the structured document generating means restores the structured document by using the rewritten document part instead of the reference information of the external part.

  By adopting such a configuration, it is possible to describe the difference from the reference part while referring to the external document as a part, and it is possible to use an external document that is not completely equal as a reference destination. External documents can be referred to by document parts. Further, it is possible to record only the minimum difference information for each part while referring to a plurality of external documents at the same time. Thereby, the object of the present invention can be achieved.

  In a preferred embodiment of the present invention, an encoded document is a list of character string parts such as an element name, an attribute name, an element value, and an attribute value, and an element part or external part reference data indicating one element. All parts are identified by a unique ID in the encoded document, and each element part is a string of its own element name, element value, attribute name, attribute value, etc. and its own child element A certain other element part is encoded so as to be referred to by the ID. Furthermore, the encoded document has an external document import declaration consisting of a reference to the external encoded document and a conversion rule of the ID in the external encoded document to the ID in the reference source document, and the external part reference data is acquired in the external document. The ID of the element part in the externally encoded document obtained by the declaration conversion rule is specified, and the difference data is described as a list of the set of the part ID to be changed and the changed ID. Then, when the encoded document is read and the external encoded document to be referred to is read, the ID of the external encoded document converted by the ID conversion rule is handled as a part of the reference encoded document.

  By adopting such a configuration, the structured document is encoded as a part of character string or element unit and referred to by ID, and at the same time, other encoded documents can be imported as if they were part of their encoded document. Furthermore, by making it possible to replace this ID as difference information of external part reference data, it is possible to import parts without rewriting by simply specifying an ID, and at the same time, importing parts with rewriting is also differential information. Can be described with small data with only two IDs.

  According to the present invention, a high compression effect can be obtained in encoding a structured document. The reason is that it is possible to generate an encoded document in which only one or more external documents are referred to as document parts and only the difference between them can be described. In particular, if you use an encoding method that encodes each element of a structured document as a part with an ID and expresses the reference between the elements with this ID, references and differences to document parts and character strings in the external document are displayed. Since it is possible to describe with small data, the compression rate can be further increased.

  Next, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

"First embodiment"
Referring to FIG. 1A, a structured document processing apparatus according to a first embodiment of the present invention includes a structured document encoding module 101 that inputs a structured document 131, generates an encoded document 121, and outputs it. From the structured document decoding module 111 that inputs the encoded document 121 and generates and outputs the same structured document 133 as the original structured document 131, and the external document 132 shared by both modules 101 and 111 Composed.

  The external document 132 is a document obtained by encoding another structured document similar to the structured document 131 using the same method as the encoded document 121.

  The structured document encoding module 101 inputs the analysis result of the structured document 131 from the structured document analyzing unit 102 and the structured document analyzing unit 102 that analyzes the structured document 131. An external document reference determination unit 104 that searches for an external document 132 similar to the external document, and an external document difference analysis that calculates a difference between the external document 132 searched by the external document reference determination unit 104 and a similar part of the structured document 131 The analysis result of the structured document 131 is input from the part 105 and the structured document analysis part 102, and difference information between the part of the structured document 131 and the similar external document 132 is input from the external document difference analysis part 105. The similar portion includes reference information to the external document 132 and an encoded document generation unit 103 that generates an encoded document 121 encoded as difference information between the reference information and reference usage information 107 generated in the course of the encoding process. And a storage unit 106 for storing.

  The structured document decoding module 111 inputs an analysis result of the encoded document 121 from the encoded document analysis unit 112 that analyzes the encoded document 121, and is included in the encoded document 121. An external document fetch unit 114 that reads the external document 132 referred to by the reference information, an external document rewrite unit 115 that rewrites the read external document 132 using the difference information included in the encoded document 121, and an encoded document analysis unit The analysis result of the encoded document 121 is input from 112, the rewritten external document is input from the external document rewriting unit 115, and the portion encoded as the reference information of the encoded document 121 is replaced with the rewritten external document. A structured document generating unit 113 that generates the structured document 133, and a storage unit 116 that stores the encoded document internal data 117 generated in the course of the decoding process.

  Here, the structured document encoding module 101 and the structured document decoding module 111 can be realized by a computer having at least a CPU, a main memory, and an external storage device, for example. In this case, the computer that implements the structured document encoding module 101 and the computer that implements the structured document decoding module 111 may be the same computer or different computers.

  Next, the overall operation of this embodiment will be described in detail with reference to the block diagram of FIG. 1A and the flowcharts of FIGS. 2A and 3.

  In the structured document encoding module 101, first, in step S201, the structured document analysis unit 102 analyzes the structured document 131 to be encoded.

  In step S202, the external document reference determination unit 104 searches the external document 132 for a similar document part included in the analyzed structured document 131. In the case of the present embodiment, the encoded document obtained by encoding another structured document is used as the external document 132. For example, the external document 132 decoded into the structured document and the document included in the structured document 131 are used. Compare parts and search for similar external documents. Alternatively, a similar external document may be searched by comparing the external document 132 with the encoded structured document 131 assuming that no external document is available. Here, “similar” includes a case where they are completely coincident with each other and a case where they are not completely coincident but are similar to such a degree that a predetermined condition is satisfied.

  If similar external documents are found as a result of the above search (Y in step S203), the external document difference analysis unit 105 compares similar document parts between the structured document 131 and the external document 132, and the difference information Is calculated (step S204). The difference between the reference information of the external document 132 including similar document parts, the position of the similar document part in the external document 132, the position of the document part where the similar external document is found in the structured document 131, and the difference. The information is stored in the storage unit 106 as reference usage information 107 (step S205).

  Next, the encoded document generation unit 103 encodes the structured document 131 to be encoded, and generates an encoded document 121 (step S206). At this time, the encoded document generation unit 103 checks the presence or absence of the reference usage information 107. If the reference usage information 107 is present, the encoded document part 103 in the structured document 131 described in the reference usage information 107 is encoded. Instead, external component reference data 122 is generated and described in the encoded document 121 instead. The external component reference data 122 has the reference information of the external document 132 of the reference usage information 107 as the external document reference data 123, and the position of a similar document component in the external encoded document 132 as the component reference data 125. The difference information is stored as difference data 124. Here, the external component reference data 122 is expressed in the form of a structured document and is encoded in the same manner as other elements.

  The encoded document 121 obtained by encoding the structured document 131 is transmitted from the structured document encoding module 101 to the structured document decoding module 111.

  In the structured document decoding module 111, first in step S301, the encoded document analysis unit 112 analyzes the encoded document 121, and the analysis result is stored in the storage unit 116 as encoded document internal data 117. Next, the external document fetch unit 114 refers to the analysis result, and checks whether the external component reference data 122 is included in the encoded document 121 (step S302). The external document 132 referred to by the external document reference data 123 is read for all the external component reference data 122 (step S303). Further, the external document rewriting unit 115 rewrites the document part specified by the part reference data 125 of the read external document 132 using the difference data 124 (step S304), and the encoded document stored in the storage unit 116 The element part that was the external part reference data 122 in the internal data 117 is replaced with the rewritten document part (step S305). When the replacement of all the external part reference data 122 with the document parts is completed, finally, the structured document generating unit 112 generates the structured document 133 from the encoded document internal data 117 in the storage unit 116 (step S306).

  In the present embodiment, the encoding method and format of general elements in the encoded document 121 are not stipulated, but the external component reference data 122 itself is expressed in the form of a structured document, and other elements and It will be apparent that various conventional structured document encoding methods can be used in the same way. In addition, it is obvious that it is possible not to encode as an encoding method, that is, to adopt a structured document itself as a format.

  In this embodiment, the method of calculating the difference between the structured document and the externally encoded document and the method of expressing the difference data are not particularly defined, but this is because various existing technologies can be used. It will be clear. For example, Patent Document 3 discloses a variety of difference calculation methods, a method for expressing difference data in XSLT, and the like.

  In the present embodiment, the method by which the external document reference determination unit 104 searches the external document 132 is not particularly defined. However, as a preferred embodiment, the external document 132 is stored in a database, a secondary storage device, or a structured document. Place on a server connected to the encoding module 101 and structured document decoding module 111 via a network, send search requests to them and receive the results, or acquire all documents and determine external document references A method may be considered in which the unit 104 itself determines similarity.

  In the present embodiment, an encoded document is used as an external document. However, it goes without saying that a structured document can be used as an external document.

  Next, the effect of this embodiment will be described.

  In the present embodiment, the external document reference determination unit 104 determines an external document 132 that can be used as a component at the time of encoding, the external document difference analysis unit 105 analyzes the difference between the components, and the encoded document generation unit 103 Instead of the original part, external part reference data 122 consisting of a set of external document reference data 123, part reference data 125, and difference data 124 is generated, and the external document import unit 114 specifies the external document reference data 123 when decrypting. The read external document 132 is read, the document part specified by the part reference data 125 is taken out, the external document rewriting unit 115 rewrites the read part using the difference data 124, and the structured document generation unit 113 is used by using it. However, since the structured document is decrypted, a slightly different external document can be referred to as a part. As a result, a larger number of external documents can be used as reference destinations, and at the same time, only the difference information from the reference destination needs to be described in the encoded document 121, so the compression rate of the encoded document 121 can be increased. It becomes. In addition, a plurality of external documents are referred to as similar parts, and differences are described for each part. Therefore, even a structured document that is described by combining a plurality of contents can be encoded with a small amount of information. Can be done.

“Second Embodiment”
In the first embodiment, the storage location of the external document 132 searched by the external document reference determination unit 104 and acquired by the external document capture unit 114 is not particularly limited, but in this embodiment, the storage location is shown in FIG. 1B. The shared document storage unit 109 for storing the external document 132 is provided, and the external document 132 is searched and acquired from the shared document storage unit 109. At the same time, the encoded document 121 created by the structured document encoding module 101 is set as a new external document. It is automatically added to the shared document storage unit 109.

  Referring to FIG. 1B, the structured document encoding module 101 further includes an encoded document storage unit 108 and is connected to a shared document storage unit 109. The structured document decryption module 111 is also connected to the shared document storage unit 109.

  Next, the operation of this embodiment will be described with reference to the block diagram of FIG. 1B and the flowchart of FIG. 2B.

  The steps from the analysis step S201 of the structured document 131 in the structured document encoding module 101 to the step S206 of generating the encoded document 121 are the same as the operations in the first embodiment. When the generation of the encoded document 121 is completed in step S206, the encoded document storage unit 108 of the structured document encoding module 101 checks whether or not the generated encoded document 121 refers to the external document 132 ( Step S207). If no reference is made, there is no external document 132 similar to the structured document 131 in the shared document storage unit 109, so the encoded document 121 generated this time is stored as a new external document. Is added to the unit 109 (step S208).

  If the external document 132 has been referenced, the encoded document storage unit 108 checks whether or not the difference from the referenced external document 132 is greater than a predetermined amount (step S209). The described document component is added to the shared document storage unit 109 as one encoded document (external document) (step S210).

  In this way, the structured document module 101 automatically generates all or part of the generated encoded document as an external document when there is no similar external document or when there is a large difference even if it exists. By accumulating, the number of external documents that can be referred to increases, and a high compression effect can be obtained as processing proceeds.

  In the present embodiment, the structured document encoding module 101 adds a new external document to the shared document storage unit 109. However, the same functional means as the encoded document storage unit 108 is used for the structured document decoding unit. The structured document decryption module 111 may add a new external document to the shared document storage unit 109 by being provided in the composition module 111.

“Third embodiment”
Referring to FIG. 4A, the structured document processing apparatus according to the third exemplary embodiment of the present invention inputs a structured document 131, generates an ID-type encoded document 421, and outputs it. A structured document decoding module 111 that inputs the ID type encoded document 421 and generates and outputs the same structured document 133 as the original structured document 131, and an external shared by both modules 101 and 111. The document 432 is composed.

  In the present embodiment, an ID type encoding method is used as an encoding method. The ID-type encoding method divides the components of a structured document into character string parts (element names, attribute names, element values, attribute values, etc.) and element parts, and assigns IDs to each other and uses them as IDs. This is a method of encoding by referring to.

  The external document 432 is a document obtained by encoding a structured document different from the structured document 131 using the ID type encoding method.

  The structured document encoding module 101 inputs the analysis result of the structured document 131 from the structured document analyzing unit 102 and the structured document analyzing unit 102 that analyzes the structured document 131. An external document reference determination unit 104 that searches for an external document 432 that encodes another structured document similar to the above, and a similar part of the external document 432 and the structured document 131 searched by the external document reference determination unit 104 The external document difference analysis unit 105 that calculates the difference between the structured document 131 and the structured document analysis unit 102 inputs the analysis result of the structured document 131. An ID type encoded document generation unit 403 that inputs difference information with a document and generates an ID type encoded document 421 that is encoded as difference information between the reference information to the external document and the similar part, and encoding processing A storage unit for storing the reference usage information 107 generated in the process of 106.

  The structured document decoding module 111 receives an ID type encoded document analysis unit 412 that analyzes the ID type encoded document 421, and inputs an analysis result of the ID type encoded document 421 from the ID type encoded document analysis unit 412. The ID type external document fetch unit 414 that reads the external document 432 referred to by the reference information included in the ID type encoded document 421, and the difference information included in the ID type encoded document 421 is used for the read external document 432. The ID type external document rewriting unit 415 to be rewritten and the ID type encoded document analysis unit 412 are input the analysis result of the ID type encoded document 421, and the external document rewritten from the ID type external document rewriting unit 415 is input, An ID-type structured document generation unit 413 that generates a structured document 133 by replacing a portion encoded as reference information of the ID-type encoded document 421 with the rewritten external document, and is generated during the decoding process And a storage unit 116 for storing the ID table 417.

  Referring to FIG. 5, the ID type encoded document 501 showing the configuration example of the ID type encoded documents 421 and 432 is equal to the number of external documents referred to when the external document is referred to. It consists of a document capture declaration 502 and a list of one or more parts 503. The part 503 is one of a character string part, an element part, and an ID type external part reference data, and has a unique ID in the encoded document.

  Referring to FIG. 6, an external document import declaration 601 showing a configuration example of the external document capture declaration 502 is indicated by ID type external document reference data 602 indicating an external document to be captured and the ID type external document reference data 602. An ID conversion rule 603 indicating how to convert an ID appearing in an external document. In the ID conversion rule 603, the ID of the part appearing in the external document indicated by the ID type external document reference data 602 is the ID in the structured document 131 appearing in the ID type encoded document 421 to be generated or other ID type. The rule is set so that it does not overlap with an ID appearing in an external document indicated by the external document reference data 602.

  Referring to FIG. 7, a character string type component 701 showing a configuration example of a component 503 in the case of a character string component has a character string 702. A character string 702 is a character string representing an element name, an element value, and the like.

  Referring to FIG. 8, an element component 801 showing a configuration example of a component 503 in the case of an element component includes an element name ID 802, an element value ID 803, an attribute table 804 including a list of attribute name IDs and attribute value IDs, and child element IDs. It has a child element table 805 consisting of a list of In other words, as described above, a structured document forms a tree structure with one element as a root, and each element is composed of an element name, element value, attribute name, attribute value, child element list, etc. Each element component is a single element expressed using an ID.

  Referring to FIG. 9, ID type external part reference data 901 showing a configuration example of a part 503 in the case of ID type external part reference data is difference data composed of a reference destination ID 902, a pre-change ID and a post-change ID list. With 903. The reference destination ID 902 designates which document part in the external document specified by the ID type external document reference data 602 of the external document import declaration 601 is referred to by the ID of the document part. The combination of the before-change ID and the after-change ID in the difference data 903 represents which part in the document part specified by the reference ID is replaced by which part by the combination of the IDs of the parts before and after the replacement. Here, the reference ID 902 uses an ID obtained as a result of applying the conversion rule 603 of the external document import declaration 601 to the document part ID in the external document. Similarly, when describing the ID of a part in an external document using difference information, the ID obtained as a result of applying the conversion rule 603 of the external document import declaration 601 to the ID attached to the part in the external document is used. To do.

  Referring to FIG. 10, an ID table 1001 showing a configuration example of the ID table 417 stored in the storage unit 116 in the course of the decryption process includes an ID and a list of parts indicated by the ID table.

  Next, the overall operation of the present embodiment will be described in detail.

  In the structured document encoding module 101, first, in step S201 of FIG. 4B, the structured document analyzing unit 102 analyzes the structured document 131 to be encoded, and then in step S202, the external document reference determining unit 104 A document having a document part similar to the document part included in the analyzed structured document 131 is searched from the documents 432. In the case of the present embodiment, the ID type encoded document obtained by encoding another structured document with the ID type encoding method is set as the external document 432. For example, the ID type encoded document 432 is decoded into the structured document. A similar external document is searched by comparing the processed part with the document part included in the structured document 131. Alternatively, a similar external document may be searched by comparing the external document 432 with an ID-type encoded structure of the structured document 131 on the assumption that no external document can be used. Here, “similar” includes a case where they are completely coincident with each other and a case where they are not completely coincident but are similar to such a degree that a predetermined condition is satisfied.

  If a similar external document 432 is found as a result of the above search (Y in step S203), the external document difference analysis unit 105 compares similar document parts between the structured document 131 and the external document 432, and the difference Information is calculated (step S204). The difference between the reference information of the external document 432 including the similar document parts, the position of the similar document parts in the external document 432, the position of the document part where the similar external document is found in the structured document 131, and the difference. The information is stored in the storage unit 106 as reference usage information 107 (step S205).

  Next, the ID type encoded document generation unit 103 encodes the structured document 131 to be encoded by the ID type encoding method, and generates an ID type encoded document 421 (steps S211 and S212). In this embodiment, at the time of this encoding, the ID type encoded document generation unit 403 uses the ID type external document 432 indicating the ID type encoded document 432 as reference information for the external document 432 determined by the external document reference determination unit 104. The external document import declaration 601 including the document reference data 602 and the ID conversion rule 603 is encoded separately from the external component reference data. Furthermore, the ID type encoded document generation unit 403 converts the structured document 131 into a character string part used for an element name, an attribute name, an element value, an attribute value, an element part indicating one element, an ID type Encoding is made up of a list of external component reference data. Here, the element part and the ID type external part reference data are encoded so that the character string part and other element parts are referred to by specifying the ID. For the ID of the reference destination, specify an appropriate ID for the part in the structured document 131 to be processed, and the part for the part in the external ID type encoded document 432 specified by the external document import declaration 601 Specify the ID that is the result of converting the ID assigned in the external document by the ID conversion rule.

  The ID type encoded document 421 obtained by encoding the structured document 131 by the ID type encoding method is transmitted from the structured document encoding module 101 to the structured document decoding module 111.

  On the other hand, in the structured document decoding module 111, first in step S301 in FIG. 4C, the ID type encoded document analysis unit 412 analyzes the ID type encoded document 421, and based on the analysis result, as the encoded document internal data, An ID table 417, which is a conversion table between IDs and corresponding component data, is created (step S311).

  Next, the ID type external document capturing unit 414 uses the ID type external document reference data 602 for all the external document capture declarations 601 included in the ID type encoded document 421, and is an external document that is an ID type encoded document. 432 is read (steps S302 and S303), all IDs in the external document are converted using the ID conversion rule 603 (step S312), and added to the ID table 417 (step S313). Further, the ID type external document rewriting unit 415 uses the ID type external part reference data 901 to identify the corresponding part in the ID table 417 of the ID type external part reference data 901 as the ID part indicated by the reference destination ID 902. If the ID of the part referenced indirectly from the element indicated by the reference ID 902 or indirectly through the child or grandchild element is found, and if an ID equal to the pre-change ID of the difference data 903 is found there, the ID table 417 The part with the pre-change ID is replaced with the part with the post-change ID (step S314).

  Finally, the ID-type structured document generation unit 413 uses the ID table 417 to resolve the ID and refer to the parts in order from the root element of the structured document, and restore the structured document 133 from the ID table 417. (Step S306).

  Next, the effect of this embodiment will be described.

  In the present embodiment, as a specific method of encoding, in particular, an ID type encoding method is used in which components of a structured document are decomposed into character strings and elements, IDs are individually assigned and mutually referenced by IDs, Each part can be referred to by ID, and the parts in the external ID type encoded document can be handled as parts in the own document by the external document import declaration. Difference information can be expressed as ID designation or ID substitution, and it is possible to import and encode an external document with smaller data.

  In addition, as a unit of information to be referenced, it is possible to refer to parts in external documents not only in document parts of structured documents but also in character string units such as element names, element values, attribute names and attribute values. Character strings specified in the document structure definition of structured documents and other arbitrary character strings are frequently used in advance in external structured documents and shared by the encoding module and decoding module Then, since it is only necessary to describe only the reference to each ID type encoded document, it is possible to obtain a compression effect of a higher size.

"Other embodiments"
In the first to third embodiments, the structured document decryption module 111 reads and analyzes an external document from the outside at the time of decryption, but caches this in the storage unit in an analyzed state. You can keep it. When a similar structured document is decrypted many times, the same external document is used many times, so that the processing load of the decryption process can be reduced.

  In the first to third embodiments, both the input of the structured document encoding module 101 and the output of the structured document decoding module 111 are structured documents. However, these are handled in an analyzed form. It may be. The preferred embodiment in the parsed form is an object that can be used through the DOM API or the SAX API, or a structured document converted into a class definition or variable of a programming language object. An example of a class definition or converted into a variable is a Java Beans component of the Java (registered trademark) programming language. Furthermore, if the analyzed form is a form in which a difference from an external document can be easily calculated, a more efficient encoding process can be performed.

  In the first to third embodiments, the external document reference determination unit 104 does not particularly define a method for determining an external document to be used when a plurality of external documents that can be used for the same document part are found. However, this may be determined so that the size of the generated encoded document is minimized.

  Next, the operation of the embodiment of the present invention will be described in more detail using specific examples.

  FIG. 11 is a configuration diagram of an example of a communication system realized by using the structured document processing apparatus according to the third embodiment of the present invention. There is a message transmission system 1126 having a structured document encoding module 101, and a transmission application 1121 for creating a message is connected. Further, there is a message reception system 1127 having a structured document decryption module 111, and a reception application 1122 that uses the message is connected. The message transmission system 1126 and the message reception system 1127 are connected via a network 1123. The message transmission system 1126 and the message reception system 1127 have shared document storage units 1124 and 1125 that hold shared external documents to be referenced. It is assumed that the shared document storage unit 1124 and the shared document storage unit 1125 are managed so as to always hold the same content by an arbitrary method.

  FIG. 12 shows an example of a structured document that the transmission application 1121 wants to send to the reception application 1121. This example is a SOAP communication protocol message described in XML as a structured document, but of course the subject of the present invention is not limited to this. For example, HTML, SGML, etc. can be used as a structured document description method. Conceivable.

  Hereinafter, the operation of the present embodiment in each situation will be described assuming some kinds of documents stored in the shared document storage units 1124 and 1125.

  First, as a first situation, an operation in a situation where no document similar to the shared document storage units 1124 and 1125 is stored will be described in order to explain the ID encoding method used in this embodiment.

  In this case, when the transmission application 1121 passes the structured document 1201 of FIG. 12 to the message transmission system 1126, the structured document analysis unit 102 first analyzes the structured document 1201 and references it using the external document reference determination unit 104. Search for possible external documents. However, since no external document is found here, the entire structured document 1201 is encoded by the ID-type encoded document generation unit 403 into an ID-type encoded document.

  FIG. 13 shows an example of the generated ID type encoded document 1301. In this embodiment, a natural number is used as an ID for a component. For simplification of explanation, the handling of attribute names, attribute values, name spaces, etc. is omitted. In this example, since there is no external document to be referenced, the external document import declaration is empty. IDs 1 to 15 are character string parts, of which 1 to 10 are element names and 11 to 15 are element values. IDs 16 to 25 are element parts, and element names, element values, child elements, etc. are referred to by ID. In this embodiment, it is assumed that the element part or ID type external part reference data that appears first in the encoded document is regarded as the root element of the structured document.

  When the encoded document 1301 shown in FIG. 13 is transferred to the message receiving system 1127 via the network 1123, first, the ID type encoded document analysis unit 412 analyzes the encoded document 1301 and creates an ID table 417. An ID table 1401 shown in FIG. 14 is an ID table generated at this time. This is equivalent to the encoded document 1301 with the external document import declaration removed. Next, the ID-type external document fetch unit 414 fetches an external document using the external document fetch declaration, but nothing is done here because the external document fetch declaration is empty. Finally, the ID-type structured document generation unit 413 uses the ID table to resolve the necessary element names, element values, and child elements using the ID = 16 element, which appears first, as the root. Meanwhile, the structured document 1201 is generated, and the generated structured document is passed to the receiving application 1122.

  Next, as a second situation, an example in which the structured document of FIGS. 15 and 16 is ID-encoded and stored in the shared document storage units 1124 and 1125 will be described.

  In the SOAP communication protocol, in general, the header holds communication control information that does not depend on an application, and the body holds information that depends on an individual application, and uses them in any combination. It shows the situation where document parts are prepared for each of Header and Body. Among specific element values, To and UserID are fixed when a message is exchanged between the same communication apparatuses, and the values are described in the document part. On the other hand, other MessageID, OrderID, and ProductID have different values for each message, so a dummy value is described in the external document.

  FIGS. 17 and 18 are obtained by ID-coding the structured documents of FIGS. 15 and 16, respectively. The ID-type encoded documents 1701 and 1801 are respectively stored in the shared document storage units 1124 and 1125, respectively. The encoded document 1701 is saved as Header1 and the ID-type encoded document 1801 is saved as Body1. The ID type encoding method is the same as in the first situation.

  Here, when the transmission application 1121 passes the structured document 1201 of FIG. 12 to the message transmission system 1126, the structured document analysis unit 102 first analyzes the structured document 1201 and references it using the external document reference determination unit 104. Search for possible external documents. Here, a similar document is not found for the Envelope element, but the ID type encoded document 1701 is found for the Header element of its child element, the ID = 6 element of the document Header1 is found as a similar document, and the ID type encoded document for the Body element In 1801, the element with ID = 10 in the document Body1 is found as a similar document.

  Next, the external document difference analysis unit 105 compares the document part below the Header element of the structured document 1201 with the document part of the ID type encoded document 1701 and the ID = 6 element of the document Header1 that are found, and the MessageID element Only the element value is changed to 0123456, and the reference usage information 1107 describing these pieces of information is generated and recorded in the memory 1106. Similarly, compare the document parts below the Body element of the structured document 1201 with the document parts of the ID type encoded document 1801 and the ID = 10 element of the document Body1, and change the element values of the OrderID element and ProductID element. The reference usage information 1108 describing these pieces of information is generated and recorded in the memory 1106.

  Next, the ID type encoded document generation unit 403 performs ID type encoding of the structured document 1201. Since reference usage information exists here, first, external documents corresponding to the external ID type encoded documents 1701 and 1801 respectively. A capture declaration 601 is generated. Here, as the external document import declaration 601 for the ID type encoded document 1701, a document name “Header1” of the ID type encoded document 1701 is set with, for example, “add 100 to ID” as the ID conversion rule. . Similarly, an external document import declaration 601 for the ID type encoded document 1801 is created by setting the document name “Body1” of the ID type encoded document 1801 and setting, for example, “200 addition to ID” as the ID conversion rule. .

  Next, each element of the structured document 1201 is encoded as a character string component and an element component. The Header element and the Body element are encoded as ID type external component reference data 901 instead of the element component. Here, for the Header element, first, the value of the changed element value 0123456 is created as a character string component with ID = 2, and 106 is obtained by adding 100 to 6 as the reference destination ID as the ID type external component reference data 901. In the difference data, the pre-change ID is 4 + 100, 104, and the post-change ID is 2 of the character string part registered earlier, and this is registered as a child element of the Envelope element instead of the Header element. Similarly, for the Body element, the changed element values order1 and 4600 are created as character string parts with ID = 3 and ID = 4 respectively, and the ID type external part reference data 901 is set to 210 as the reference destination ID and the difference Create the data with the pre-change ID of 207, the post-change ID of 3, the pre-change ID of 209, and the post-change ID of 4, and register this as a child element of the Envelope element instead of the Body element. The encoded document thus created is the ID-type encoded document 1901 in FIG. 19, where ID = 6 and ID = 7 become ID-type external component reference data 901.

  The ID type external part reference data 901 with the first ID = 6 corresponds to the first external document import declaration, and the part of “reference ID = 106” is the ID of the corresponding external document import declaration 17 indicates that the document part with ID = 6 (106-100) in the ID-type encoded document of FIG. 17 indicated by the type external document reference data is fetched as a part with ID = 6, and “difference (old, new) = (104, 2) ”indicates that the character string (that is, MessageID) of ID = 4 (104-100) in the captured document part is replaced with the character string of ID = 2 (that is, 01234567). Similarly, the ID type external part reference data 901 with the second ID = 7 corresponds to the second external document import declaration, and the part of “reference destination ID = 210” is the corresponding external document capture. 18 indicates that the document part with ID = 10 (210-200) in the ID type encoded document shown in FIG. 18 indicated by the ID type external document reference data in the declaration is fetched as the part with ID = 7, and “difference (old, new) = (207,3) ”replaces the string of ID = 7 (207-200) (ie, order0) in the imported document part with the string of ID = 3 (ie, order1). "Difference (old, new) = (209, 4)" is the character string with ID = 9 (209-200) (that is, pid0) in the imported document part is replaced with the character string with ID = 4 (that is, 4600) Each indicates that it will be replaced.

  Here, the ID type external component reference data 901 with the first ID = 6 in FIG. 19 corresponds to the first external document import declaration, and the ID type external component reference data 901 with the second ID = 7. There is no information in the encoded document 1901 that clearly indicates that corresponds to the second external document capture declaration. The reason for this is that, as will be described later with reference to FIG. 21, by converting the ID in the external document specified in the external document import declaration by the conversion rule at the time of decryption, This is because the relationship with the ID in the external document is uniquely determined.

  In the above description, the ID and ID conversion rule in the encoded document to be generated are appropriately determined in consideration of the image of the encoded document that has been completed in advance for easy explanation, but this determination method may be arbitrary. For example, in the process of processing one element at a time, an appropriate thing is shaken and a contradiction appears, or all IDs are reassigned when creating an encoded document at the end, or the entire structured document is analyzed once. It would be easy for an engineer with ordinary skills to easily check the document size and determine the number of required IDs before processing.

  Next, when the ID type encoded document 1901 as shown in FIG. 19 is passed to the message receiving system 1127 via the network 1123, the structured document decoding module 111 first analyzes the ID type encoded document 1901, A table 417 is generated. An ID table 2001 in FIG. 20 shows an example of the contents of the ID table 417 in this state. Next, the ID-type external document capturing unit 414 refers to the two external document capture declarations, reads the two documents, and adds the ID converted by the ID conversion rule to the ID table 417. An ID table 2101 in FIG. 21 is an ID table 417 in this state, and parts with IDs in the 100s and 200s are added parts here.

  Next, the ID type external document rewriting unit 415 rewrites the ID table 417 using the ID type external component reference data with ID = 6,7. First, looking at the ID type external part reference data with ID = 6, the data with ID = 6 from the reference ID is replaced with the part with ID = 106, and the part with ID = 104 from the difference data is replaced with the part with ID = 2. Next, look at the ID type external part reference data with ID = 7, from the reference ID to ID = 7 data to ID = 210 parts, from the difference data ID = 207 parts to ID = 3 parts, ID = Replace 209 part with ID = 4 part. An ID table 2201 in FIG. 22 is an ID table 417 in this state, and a portion with an arrow before the ID is the rewritten ID.

  Finally, the ID type structured document generation unit 413 uses the ID table 417 to generate a structured document 1201 while searching for elements and character strings using IDs from the ID = 5 component that is the root element, The generated structured document is passed to the receiving application 1122.

  Next, as a third situation, an example will be described in which the ID type encoded version of the structured document 2301 in FIG. 23 is stored in the shared document storage units 1124 and 1125.

  The structured document 2301 in FIG. 23 is the same as the structured document 1201 to be transmitted in FIG. 12 except that the element value that changes every time is a dummy value. An ID type encoded document 2401 shown in FIG. 24 is obtained by ID-type encoding, and is stored under the name Message1. However, here, the structured document 2301 is not only simply ID-type encoded, but at the end of the encoded document, the character string component ID = 26, ID = 27 and ID = 28 are added. This often means that the entire structured document can be used as a part in communication using a structured document whose structure is exactly the same and only some values change, and more frequently. The character string used is intended to be prepared as an unused part in the external document.

  Since the operation procedure is the same as the second situation, only the generated encoded document is described here. FIG. 25 shows the generated ID type encoded document. In the ID type encoded document 2501, the element of the external document is directly referred to as the root element, and only the difference between the character string components of the element value is described. Furthermore, for the element value 4600 of the element ProductID, the character string component ID = 26 (126 after the ID conversion in the difference data) is referenced in the external encoded document 2401 of the reference destination, and ID type encoding In the document 2501, only the character strings 01234567 and order1 are described, and the character string 4600 is not described.

  Many application systems that exchange many messages over a long period of time often send and receive a large number of messages that have the same document structure but differ only in values such as element values and attribute values. If you prepare an external document that shares the full-text template, you can communicate just by writing the changed value string and some reference information, as shown in this example, and it is extremely high in size. A compression effect can be obtained. Furthermore, if you learn the character strings included in the exchanged messages and add frequently used ones to external documents that are shared more and more, it becomes possible to handle more character strings by reference only, and even higher sizes. It is possible to obtain a compression effect.

  Further, such unused parts for reference use are not limited to character string parts such as element values and attribute values, but may be character strings representing structures such as element names and attribute names, and element parts. For example, an external document in which all character strings such as element names, element values, attribute names, and attribute values obtained from the document structure definition of structured documents are shared in advance, and individual communication messages are By describing the entire structure such as the relationship between the elements of the entire document while referring to the prepared external document, it is possible to obtain the same effect as the conventional structure information external reference type binary representation method.

  In the above description, the replacement of the character string component is mainly described as the difference data, but the replacement target may be an element component. Since only the ID is described in the difference data 903, the replacement of the character string component and the replacement of the element component can be handled in the same manner.

  Assume that the structured document 2601 in FIG. 26 is transmitted in the third situation. However, an ID-coded version of the structured document 2301 in FIG. 23 stored in advance is a character string component that is not referred to as ID shown in FIG. A string component "SessionID" has been added. In the structured document 2601, elements called SessionID and TransactionID are added to the Header with respect to the structured document 1201 of FIG. 12 used in the above description.

  Since the operation procedure is the same as the second situation, only the generated encoded document is described here. FIG. 27B shows the generated ID type encoded document 2701. In the ID type encoded document 2701, as compared with the ID type encoded document 2501 in FIG. 25, replacement of the header element with an element in which two child elements of ID = 8 and ID = 9 are added to the difference data (117, 7) Are added, and the added elements and parts of ID = 3,4,5,7,8,9 for configuring the element names and element values are added. However, for the element called SessionID, the character string component ID = 29 prepared in the reference destination document 2702 as the element name is referred to as the post-conversion ID = 129.

  In this way, it is possible to replace elements as difference data, and at the same time, it is possible to add new elements that are not assumed at all in the externally encoded document shared in advance.

  As described above, the compression ratio of the size of the encoded document varies depending on the type of the shared encoded document prepared in advance. The types of documents that can be shared in advance between the structured document encoding module 101 and the structured document decoding module 111 vary depending on the application and operating environment used, and are not necessarily encoded from the beginning. Since the type and shape of the structured document to be obtained are not always clear, a sufficient amount of shared encoded documents cannot always be prepared. In this case, the compression effect is limited at first, but it is possible to increase the compression effect more and more by expanding the encoded document shared from the execution history during the operation of the system.

  It should be noted that some situations of the shared encoded document described above are merely examples, and it can be easily guessed by an engineer having ordinary ability that various ways of sharing the encoded document can be considered. Will.

  Although the present invention has been described with reference to some embodiments and examples, the present invention is not limited to the above examples, and various other additions and modifications are possible. In addition, the structured document encoding apparatus and decoding apparatus of the present invention can be realized by a computer and a program as well as the functions of the hardware. The program is provided by being recorded on a computer-readable recording medium such as a magnetic disk or a semiconductor memory, and is read by the computer at the time of starting up the computer, etc. And function as a structured document encoding module and a structured document decoding module in the above-described form, and execute the above-described processes.

  According to the present invention, in a communication apparatus using a structured document, the present invention can be applied to applications such as reducing the amount of communication data and processing load. In addition, the input / output load of secondary storage in devices that frequently store and read structured documents in secondary storage devices such as files and databases for the purpose of swapping from the main storage device or making document data permanent. It can also be applied to applications such as reducing the processing load of generation and analysis.

1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention. FIG. 5 is a block diagram showing a configuration of a second exemplary embodiment of the present invention. 6 is a flowchart showing the operation of the structured document encoding module according to the first embodiment of the present invention. 10 is a flowchart showing the operation of the structured document encoding module according to the second embodiment of the present invention. 6 is a flowchart showing the operation of the structured document decryption module according to the first embodiment of the present invention. FIG. 10 is a block diagram showing a configuration of a third exemplary embodiment of the present invention. 16 is a flowchart showing the operation of the structured document encoding module in the third embodiment of the present invention. 16 is a flowchart showing the operation of the structured document decryption module according to the third embodiment of the present invention. FIG. 10 is a configuration diagram of an ID-type encoded document according to a third embodiment of the present invention. FIG. 10 is a configuration diagram of an external document take-in declaration in the third embodiment of the present invention. FIG. 10 is a configuration diagram of a character string type component according to a third embodiment of the present invention. FIG. 10 is a configuration diagram of element parts in a third embodiment of the present invention. FIG. 10 is a configuration diagram of ID-type external component reference data according to a third embodiment of the present invention. FIG. 10 is a configuration diagram of an ID table in the third embodiment of the present invention. It is a block diagram which shows the structure of the suitable Example of this invention. It is explanatory drawing of the structured document used as the compression object in the preferable Example of this invention. It is explanatory drawing of an example of the encoding document produced | generated in the preferable Example of this invention. It is explanatory drawing of the ID table in the preferable Example of this invention. It is explanatory drawing of the structured document prepared as the external document in the preferable Example of this invention. It is explanatory drawing of another structured document prepared as an external document in the preferable Example of this invention. It is explanatory drawing of the encoding document prepared as an external document in the preferable Example of this invention. It is explanatory drawing of another encoding document prepared as the external document in the preferable Example of this invention. It is explanatory drawing of the other example of the encoding document produced | generated in the preferable Example of this invention. It is explanatory drawing of the ID table in the preferable Example of this invention. It is explanatory drawing of the ID table in the preferable Example of this invention. It is explanatory drawing of the ID table in the preferable Example of this invention. It is explanatory drawing of the structured document prepared as an external document in the preferable Example of this invention. It is explanatory drawing of the encoding document prepared as an external document in the preferable Example of this invention. It is explanatory drawing of the encoding document produced | generated in the preferable Example of this invention. It is explanatory drawing of the structured document made into the compression object in the preferable Example of this invention. It is explanatory drawing of the encoding document prepared as an external document in the preferable Example of this invention. It is explanatory drawing of the encoding document produced | generated in the preferable Example of this invention. It is a block diagram which shows the structure of the full text holding type | formula binary expression system which is a prior art. It is a block diagram which shows the structure of the structural information external reference type | mold binary representation system which is a prior art. It is a block diagram which shows the structure of the difference sending system which is a prior art. It is a block diagram which shows the structure of the document components taking-in method which is a prior art.

Explanation of symbols

101 ... Structured document encoding module
102 ... Structured document analysis unit
103 ... Encoded document generator
104 ... External document reference determination unit
105 ... External document difference analysis part
106: Memory unit
107… Reference usage information
108: Encoded document storage unit
109… Shared document storage
111 ... Structured document decryption module
112 ... Encoded document analysis unit
113 ... Structured document generator
114… External document import section
115 ... External document rewriting part
116… Memory unit
117 ... Encoded document internal data
121 ... Encoded document
122… External part reference data
123… External document reference data
124 ... Differential data
125… Part reference data
131, 133 ... structured documents
132 ... External document (encoded document)
403 ... ID type encoded document generator
412 ... ID type encoded document analysis section
413 ... ID type structured document generator
414 ... ID-type external document import unit
415 ... ID type external document rewriting part
417 ... ID table
421 ... ID type encoded document
432 ... External document (ID type encoded document)
601 ... External document import declaration
602… ID type external document reference data
603 ... ID conversion rule
701 ... String type parts
702 ... String
801 ... Element parts
802 ... Element name ID
803 ... Element value ID
804 ... Attribute table
805 ... Child element table
901… ID type external parts reference data
902 ... Reference ID
903 ... Difference data
1001 ... ID table

Claims (30)

External document reference determination means for retrieving an external document having a document part that is structurally similar to a document part included in the structured document to be encoded, and a document similar to the searched external document and the structured document to be encoded External document difference analysis means for calculating differences between parts, and document parts that are structurally similar to the document parts of the external document among the document parts included in the structured document to be encoded are referred to the document parts of the external document. An encoded document generating means for generating an encoded document encoded as difference information between information and document parts ,
The encoded document generation means uses an encoding method in which each element of a structured document is encoded as a part with an ID and a reference between the elements is expressed by this ID, and difference information between document parts is external A structured document encoding apparatus characterized in that which part of a document is replaced by which part is expressed by a combination of IDs of parts before and after the replacement .   2. The structure according to claim 1, wherein the encoded document generating means divides and encodes reference information to the document part of the external document into reference information to the external document and reference information to the document part. Document encoding device. A document storage unit for storing an external document, wherein the external document reference determination unit selects a document part that is structurally similar to the document part included in the structured document to be encoded among the external documents stored in the document storage unit. 2. The structured document encoding apparatus according to claim 1, wherein an external document is searched.   4. The structured document according to claim 3, further comprising a document storage unit that adds a part or all of the structured document encoded by the encoded document generation unit as a new external document to the document storage unit. Encoding device.   2. The structured document encoding apparatus according to claim 1, wherein the external document is an encoded document encoded by the same method as the encoding method used by the encoded document generation means. The encoded document generating means encodes the reference information to the document part of the external document including the ID conversion rule, and describes the ID of the part in the external document with the difference information. 6. The structured document encoding apparatus according to claim 5 , wherein an ID obtained as a result of applying the conversion rule is used as an ID attached to the part. 6. The structured document encoding apparatus according to claim 5 , wherein the parts before and after replacement are character strings. Among the document parts included in the structured document, a document part that is structurally similar to the document part of the external document is decoded as the reference information to the document part of the external document and the encoded document encoded as the difference information between the document parts. an apparatus for, based an external document capturing means load external document having a document part indicated by the reference information, the document module indicated by the reference information in said read external documents on the differential information External document rewriting means for rewriting, and structured document generation means for generating a structured document from an encoded document by replacing the portion encoded as the reference information and the difference information with the document part of the rewritten external document. Prepared ,
The encoded document is encoded using an encoding method in which each element of the structured document is encoded as a part with an ID and a reference between the elements is expressed by this ID, and difference information between the document parts is , Which part of the external document is replaced by which part is replaced by the ID of the parts before and after the replacement, and the structured document generation means includes the ID described in the encoded document and the external document. When the referenced ID is the ID before replacement described in the difference information, the structured document is generated by referring to the replaced ID instead. A structured document decoding apparatus characterized by the above. 9. The structure according to claim 8, wherein in the encoded document, reference information to a document part of an external document is encoded by being divided into reference information to the external document and reference information to the document part. Document decryption device. 9. The structured document according to claim 8 , further comprising a document storage unit for storing an external document, wherein the external document fetching unit reads an external document having a document part indicated by the reference information from the document storage unit. Decryption device. 11. The structured document according to claim 10 , further comprising: a document storage unit that adds a part or all of the structured document decrypted by the structured document generation unit to the document storage unit as a new external document. Decryption device. 9. The structured document decoding apparatus according to claim 8 , wherein the external document is an encoded document encoded by the same method as the encoded document. The encoded document is encoded by including the ID conversion rule in the reference information to the document part of the external document, and when the ID of the part in the external document is described by the difference information, The ID obtained as a result of applying the conversion rule to the ID attached to the part is used, and the external document fetching means follows the conversion rule for all IDs included in the read external document. 13. The structured document decryption apparatus according to claim 12, wherein the conversion process is performed. 13. The structured document decryption apparatus according to claim 12 , wherein the parts before and after replacement are character strings. A method for encoding a structured document using a computer, wherein the computer searches for an external document having a document part that is structurally similar to a document part included in the structured document to be encoded. A second step in which the computer calculates a difference between similar document parts of the retrieved external document and the structured document to be encoded; and the computer is included in the structured document to be encoded. Among the document parts, a document part that is structurally similar to the document part of the external document includes reference information for the document part of the external document and a third step of generating an encoded document encoded as difference information between the document parts. unrealized, the in the third step, the difference between the elements references between coded elements as a component attached to ID the using coding schemes is expressed by the ID, and document part of the structured document Distribution is structured document encoding method characterized by expressing a combination of the ID of the front and rear parts replaced or substituted with any parts which parts of the external document. Among the document parts included in the structured document, a document part that is structurally similar to the document part of the external document is obtained by encoding a coded document that is encoded as reference information to the document part of the external document and difference information between the document parts. a method for decoding using the computer, a first step of reading the external document having a document part indicated by the reference information, the computer is, in the reference information in said read external documents A second step of rewriting the indicated document part based on the difference information; and the computer replaces the part encoded as the reference information and the difference information with the document part of the rewritten external document. look including a third step of generating a structured document from the document, the coded document, mark as parts with the ID of each element of the structured document And the difference information between document parts is the ID of the parts before and after replacing which part of the external document is replaced by which part. In the third step, while referring to the ID and its parts described in the encoded document and the external document using the ID, the referenced ID is the difference information. A structured document decoding method characterized by generating a structured document by referring to the ID after replacement instead of the ID before replacement described in 1 . A first process for searching an external document having a document part structurally similar to a document part included in the structured document to be encoded on the computer, and the similarity between the searched external document and the structured document to be encoded Second processing for calculating the difference between the document parts, and the document parts structurally similar to the document parts of the external document among the document parts included in the structured document to be encoded are converted to the document parts of the external document. An encoding program for executing a third process for generating an encoded document encoded as difference information between reference information and document parts , wherein each element of the structured document is processed in the third process. Use an encoding method that encodes as an ID-attached part and expresses the reference between elements by this ID, and the difference information between document parts indicates which part of the external document is replaced by which part. Expressed by combination of component IDs Encoding program . 18. The code according to claim 17, wherein, in the third process, the reference information to the document part of the external document is divided and encoded into reference information to the external document and reference information to the document part. Program. The computer includes a document storage unit for storing an external document. In the first process, the computer is structurally similar to a document part included in a structured document to be encoded among the external documents stored in the document storage unit. 18. The encoding program according to claim 17 , wherein the encoded document part is searched. 20. The encoding according to claim 19 , further causing the computer to perform a fourth process of adding a part or all of the encoded structured document as a new external document to the document storage unit. program. 18. The encoding program according to claim 17 , wherein the external document is an encoded document encoded by the same encoding method used in the third process. In the third process, the reference information to the document part of the external document is encoded including the ID conversion rule, and when the ID of the part in the external document is described by the difference information, The encoding program according to claim 21 , wherein an ID obtained as a result of applying the conversion rule is used as an ID attached to the component. The encoding program according to claim 21 , wherein the parts before and after replacement are character strings. An encoded document in which a document part that is structurally similar to a document part of an external document among the document parts included in the structured document is encoded as difference information between the reference information and the document part of the external document. A first process of reading an external document having a document part indicated by the reference information in the document part , and rewriting the document part indicated by the reference information in the document part of the read external document based on the difference information In order to perform the second processing and the third processing for generating a structured document from the encoded document by replacing the portion encoded as the reference information and the difference information with the document part of the rewritten external document. The encoded document uses an encoding method in which each element of the structured document is encoded as a part with an ID and a reference between the elements is expressed by this ID. The difference information between the encoded and document parts is expressed as a combination of parts ID before and after replacing which part of the external document is replaced with which part. In the third process, While referring to the ID and its parts described in the encoded document and the external document by using the ID, if the referenced ID is the ID before replacement described in the difference information, the replacement ID instead A decryption program that generates a structured document with reference to an ID . 25. The decoding according to claim 24, wherein in the encoded document, the reference information to the document part of the external document is divided and encoded into reference information to the external document and reference information to the document part. Program. Includes a document storage section for storing the external document into the computer, the in the first process, according to claim 24, wherein the load external document having a document part indicated by the reference information from the document storage unit Decryption program. 27. The decryption according to claim 26 , further causing the computer to perform a fourth process of adding a part or all of the decrypted structured document as a new external document to the document storage unit. program. The decoding program according to claim 24 , wherein the external document is an encoded document encoded in the same manner as the encoded document. The encoded document is encoded by including the ID conversion rule in the reference information to the document part of the external document, and when the ID of the part in the external document is described by the difference information, An ID obtained as a result of applying the conversion rule to an ID attached to a component is used. In the first process, the conversion rule is obeyed for all IDs included in the read external document. 29. The decoding program according to claim 28 , wherein a conversion process is performed. 29. The decryption program according to claim 28 , wherein the parts before and after replacement are character strings.

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