JP3974606B2 - Structured document conversion apparatus, structured document conversion method and program - Google Patents

Description

  The present invention relates to a structured document conversion apparatus, a structured document conversion method, and a program for converting a structured document.

  In recent years, XML (eXtensible Markup Language) is widely used as a standard data description language. An XML document does not have a description about the appearance of the document inside the document. XSL (XML Stylesheet Language) has been formulated as a style sheet technology for browsing XML with a browser or printing on a medium such as paper. The part related to structural transformation in XSL is called XSLT (XSL Transformation). When XSLT is used, an XML document can be converted into an XML document having another structure, or converted into an HTML document.

  There are several methods for specifying an XSLT document to be used for XSLT conversion for an XML document. First, there is a method of describing a URI as Processing Instructions (PI) in an XML document. When a PI that specifies XSLT exists in the XML document, the browser performs XSLT conversion on the XML document using the XSLT, and displays the generated HTML (or text, XML document, etc.). In addition, there is a case where a specific XSLT document is designated on the browser side regardless of whether or not there is a PI that designates XSLT in the XML document. In some widely used Web browsers, when an XML document is browsed, the specification is such that the result of XSLT conversion is displayed using the XSLT document specified by the PI in the XML document.

  This XSLT conversion process needs to be performed every time an XML document is displayed, and processing cost is high. Many techniques for reducing the processing cost of XSLT conversion have been studied. For example, there is a technique called Incremental XSLT developed as an XML document editing technique. This technology has a processing flow of XSLT conversion as internal information. If the XML document is changed by the editing process, the corresponding processing flow is updated, and then HTML is output from the processing flow and the changed XML information, thereby reducing the cost of the XSLT conversion.

However, the Incremental XSLT technology is a closed XML document generated by subjecting one XML document, the XSLT document associated with the XML document, and the XML document to XSLT conversion with the XSLT document. In other words, the editing process for the determined XML document can be reflected in the HTML document determined using the information accumulated in the past XSLT conversion. However, when the other XML documents having similar contents are subjected to the XSLT conversion, Information on past XSLT conversion could not be used. For this reason, it is not suitable for the situation where a plurality of contents are handled like the Web.
Hiroshi Yao, Haruhiko Toyama, Satoshi Shirai, Tatsunori Kanai, “Web Top XML Editor -Information Organizing Tool that Enables Editing after XSLT”, De-08, IPSJ 65th National Convention Lionel Villard, Nabil Layaida, “An incremental XSLT Transformation Processor for XML Document Manipulation”, WWW2002, Hawaii, May 7-11, 2002.

  Conventionally, when a plurality of first structured documents are converted to a second structured document by XSLT conversion (for example, when edited XML document contents are converted to HTML and referred to in order, or contents If there is a plurality of first structured documents associated with the same XSLT and similar in content, for example, when the XML document content with the same content is transferred from the transmission side and converted into HTML on the reception side and referred to in order) However, each time, the XSLT conversion process had to be performed, and the load of the conversion process was heavy.

  The present invention has been made in view of the above circumstances, and can improve the efficiency of XSLT conversion processing when a plurality of first structured documents are converted to a second structured document by XSLT conversion. It is an object to provide a structured document conversion apparatus, a structured document conversion method, and a program.

  The present invention provides a first storage means for storing a first structured document, a style sheet for converting the structure of the structured document, and a style sheet associated with the first structured document. A first generating means for converting the first structured document based on the above to generate a second structured document, and a second structured document generated by the first generating means for storing the first structured document. The second storage means, the third structured document, and the same style sheet as the style sheet associated with the third structured document stored in the first storage means are associated with each other. A second generating unit configured to generate a differential structured document indicating a difference from the first structured document; and converting the differential structured document based on the style sheet associated with the third structured document. To generate the difference structured document after conversion. The first generation means, the converted difference structured document generated by the third generation means, and the first structured document that is the basis of the difference structured document. Based on the second structured document obtained by conversion based on the style sheet by means, a third document corresponding to the structured document obtained by converting the third structured document by the style sheet. And fourth generation means for generating four structured documents.

The present invention relating to the apparatus is also established as an invention relating to a method, and the present invention relating to a method is also established as an invention relating to an apparatus.
Further, the present invention relating to an apparatus or a method has a function for causing a computer to execute a procedure corresponding to the invention (or for causing a computer to function as a means corresponding to the invention, or for a computer to have a function corresponding to the invention It is also established as a program (for realizing) and a computer-readable recording medium on which the program is recorded.

  According to the present invention, when a plurality of first structured documents are converted into a second structured document by XSLT conversion, the XSLT conversion processing can be made efficient.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In the following, the structured document conversion apparatus according to the present embodiment will be described with a focus on the case where it is used as an editor that edits and saves a structured document alone, and then refers to the case where it is used together with a Web proxy cache. .

  In the present embodiment, a case where an XML document is handled as a structured document will be described as an example. The XML document may have any size, but in the present embodiment, an XML document is assumed to have a certain size. Assume that each XML document is associated with an XSLT document designated as a style. Further, in the present embodiment, a case where an HTML document is generated by performing XSLT conversion using an XSLT document on an XML document will be described.

  FIG. 1 shows a configuration example of a structured document processing apparatus according to this embodiment.

  As shown in FIG. 1, the structured document processing apparatus according to the present embodiment includes an input unit (not shown) for inputting an XML document and an XSLT document associated with the XML document, and an input XML document (input XML document). A storage unit (not shown) for storing each document such as XSLT, an XSLT determination unit 101 for determining whether Δ-XSLT conversion is possible based on the XSLT, and an XML cache for caching an XML document (in FIG. 1) (Omitted) (see 201 in FIG. 6), a ΔXML generation unit 102 that generates a ΔXML document for an input XML document with reference to the XML cache, and Δ-XSLT that performs Δ-XSLT conversion using the XSLT document for the ΔXML document The conversion unit 103, a normal XSLT conversion unit (hereinafter referred to as an XSLT conversion unit) that performs normal XSLT using the XSLT document on the input XML document Parts) 104, and a browser 105 for performing display of the document.

  As will be described later in detail, an XML document is stored in the XML cache in association with the identification information.

  As for the delivery of the XML document between the modules, the XML document may be actually delivered, or the file name or address of the XML document in the storage unit storing the XML document may be delivered. Good. The same applies to other information such as an XSLT document.

  Here, in the ΔXML document, the target input XML document is changed to another XML document similar to the input XML document (similar XML document described later) (however, the same as the XSLT document associated with the input XML document). XSLT documents are associated with each other), and the difference is compressed with respect to similar XML documents of the certain XML document. The ΔXML document is, for example, which (other) XML document the certain XML document is based on, and what change (addition / addition) to which node of the XML document the certain XML document is. Information indicating whether it corresponds to the one to which (deletion etc.) is added.

  Although the ΔHTML document will be described in detail later, generally, as described above, another HTML document (an HTML document corresponding to the above-described certain XML document) is similar to the above. This represents a difference with respect to an HTML document corresponding to a similar XML document.

  Although the Δ-XSLT transformation will be described in detail later, the Δ-XSLT transformation generally relates to the XSLT transformation using the difference information, and includes an initial XSLT transformation (described later) and a differential XSLT transformation (described later). The first XSLT transformation is generally performed by performing XSLT transformation on a pair of an XML document and an XSLT document to generate a corresponding HTML document when necessary information is not cached. Including the process of caching the information. The difference XSLT conversion is roughly equivalent to a ΔHTML document by performing XSLT conversion on a ΔXML document (which has been converted) and an XSLT document (which has been converted) when necessary information is cached. And a process of generating an HTML document corresponding to the original XML document from the HTML document corresponding to the similar XML document.

  That is, in this embodiment, when a similar XML document similar to the input XML document is cached and an HTML document corresponding to the similar XML document is available, only a difference of the input XML document with respect to the similar XML document is obtained. The XSLT conversion process is reduced by performing the XSLT conversion.

  Hereinafter, the case where a document similar to the input XML document is not cached for each module will be mainly described.

  In the structured document processing apparatus of this embodiment, when an XML document is read from the input unit, the XSLT document associated with the XML document is also read from the input unit. This XSLT document may be specified as the PI of the XML document, for example, or may be specified on the editor side or the like.

  The XSLT document read from the input unit is transmitted to the XSLT determination unit 101.

  As shown in FIG. 2, the XSLT determination unit 101 inputs an XSLT document, determines whether or not the XSLT document is an XSLT document that can be subjected to Δ-XSLT conversion, and the result of this determination (for example, Δ First control information indicating that XSLT conversion is possible (for example, True) or second control information indicating that Δ-XSLT conversion cannot be performed (for example, False) is output.

  The ΔXML generation unit 102 and the Δ-XSLT conversion unit 103 perform the ΔXML generation process and the Δ-XSLT conversion process using the XSLT document when the XSLT determination unit 101 determines that the Δ-XSLT conversion is possible. . In addition, when the XSLT determination unit 101 determines that the Δ-XSLT conversion is impossible, the XSLT conversion unit 104 performs a normal XSLT conversion process using the XSLT document.

  Here, Δ-XSLT conversion is possible by applying the same contents as an HTML document obtained by applying the XSLT document to the input XML document, and applying the XSLT document to an XML document similar to the input ML document. The obtained HTML document, the difference of the input XML document with respect to the similar XML document, and the HTML document obtained from the XSLT document (more specifically, the difference of the input XML document with respect to the similar XML document is calculated as described later. This means that it can be reproduced using a modified version and an HTML document obtained by applying a modified version of the XSLT document.

  In the above determination, if all the conditions that enable Δ-XSLT conversion are known, it is sufficient to check whether the XSLT document satisfies the condition. For example, if there are a plurality of conditions and Δ-XSLT conversion can be performed if any one of the conditions is satisfied, the XSLT document can be converted to Δ-XSLT conversion if at least one of the plurality of conditions is satisfied. If all the conditions are not satisfied, it is determined that Δ-XSLT is not possible. Also, for example, if all of the plurality of conditions are satisfied and Δ-XSLT conversion is possible, the XSLT document is determined to be capable of Δ-XSLT conversion if all of the plurality of conditions are satisfied. If any one of them is not satisfied, it is determined that the XSLT document cannot be Δ-XSLT.

  In addition, when all the conditions that make Δ-XSLT conversion impossible are known, it is only necessary to check whether or not the XSLT document satisfies the condition that makes Δ-XSLT conversion impossible (the condition that makes Δ-XSLT conversion impossible is satisfied). Otherwise, it is determined that Δ-XSLT conversion is possible).

  In addition, when it is not known whether a certain condition corresponds to a case where Δ-XSLT conversion is possible or a case where Δ-XSLT conversion is impossible, for example, the condition is regarded as applicable to a case where Δ-XSLT conversion is impossible. To determine.

  FIG. 3 shows an example of the processing procedure of the XSLT determination unit 101.

Conditions described in steps S1 to S4, that is,
-The ancestor axis and ancestor-or-self axis are not included in the XPath notation in the XSLT document.
-The XPath notation in the XSLT document does not include / (document root).
-The XPath notation in the XSLT document does not include the following-sibling axis and the preceding-sibling axis.
-The XPath notation in the XSLT document does not include a predicate (condition part surrounded by []).
Are conditions in which Δ-XSLT conversion is impossible, and this procedure example is an example of determining that Δ-XSLT conversion is possible when all of these four conditions are satisfied.
In this example procedure, the XSLT determination unit 101 examines the above conditions one by one, and determines that Δ-XSLT conversion is possible when the result of step S1 to S4 is Yes. Moreover, when it becomes No in any of step S1-S4, it determines with (DELTA) -XSLT conversion impossible at that time.

  As described above, when the XSLT determination unit 101 determines that the XSLT document cannot be Δ-XSLT converted, a normal XSLT conversion process by the XSLT conversion unit 104 is performed.

  As shown in FIG. 4, the XSLT conversion unit 104 inputs the XML document input from the input unit and the XSLT document associated with the XML document, and uses the XSLT document to perform normal XSLT conversion on the XML document. To generate an HTML document and output it. The generated HTML document is transmitted to the browser 105.

  As described above, when the XSLT determination unit 101 determines that the XSLT document can be Δ-XSLT converted, the ΔXML generation processing for the XSLT document by the ΔXML generation unit 102 and the Δ-XSLT conversion unit 103 is performed. And Δ-XSLT conversion processing.

  As shown in FIG. 5, the ΔXML generation unit 102 inputs the XML document input from the input unit, generates a ΔXML document obtained by differentially compressing the input XML document, and outputs the XML document, or outputs the input XML document. Output as is.

  As shown in FIG. 5, the Δ-XSLT conversion unit 103 inputs the input XML document or ΔXML document output from the ΔXML generation unit 102 and the corresponding XSLT document, and uses the XSLT document, An initial XSLT transformation or a differential XSLT transformation is performed on the input XML document or ΔXML document to generate an HTML document and output it. The generated HTML document is transmitted to the browser 105.

  In this embodiment, an HTML document is generated as a result of the XSLT conversion by the XSLT determination unit 101 and the Δ-XSLT conversion unit 103, but the present invention is not limited to this, and other XML documents, texts, and the like are used. It may be related to the form. In this embodiment, the destination of the conversion result is the browser 105. However, the present invention is not limited to this, and another module or application may be used.

  Hereinafter, the ΔXML generation unit 102 and the Δ-XSLT conversion unit 103 will be described in more detail.

  FIG. 6 shows a configuration example of the ΔXML generation unit 102.

  As illustrated in FIG. 6, the ΔXML generation unit 102 according to this configuration example includes a cache management unit 121, an XML differential compression processing unit 122, and a data addition unit 123.

  In the XML cache 201, an XML document processed in the past without differential compression is stored in association with the identification information.

  In the following, an example in which information specifying an XSLT document is described in an XML document will be described as an example. However, in a case where information specifying an XSLT document is not described in an XML document, an XSLT document is specified. Information to be stored may be stored in the XML cache 201 in association with the XML document.

  There are various methods for identifying individual XML documents. In the following description, a hash value that can uniquely identify an XML document (contents) is used as the identification information of the XML document. However, the present invention is of course not limited to this (the hash used in the following description). The value may be changed to other identification information).

  Note that there are various specific methods for using a hash value as identification information of an XML document. As an example, for example, “Fingerprint” is disclosed in Japanese Patent Application Laid-Open No. 2002-268935, and this can also be used.

  FIG. 7 shows an example of the processing procedure of the ΔXML generation unit 102.

  First, the cache management unit 121 obtains a hash value of the input XML document input from the input unit (step S11).

  Next, the cache management unit 121 compares the input XML document with the XML document stored in the XML cache 201, and the XML document (similar to the input XML document) has (contents). It is searched whether or not the XML document is also stored in the XML cache 201 (step S12).

  Note that the index indicating the degree of similarity between XML documents, the criteria for determining whether or not they are similar, the method of similarity search, and the like are not particularly limited, and conventional techniques may be used as appropriate.

  When similar XML documents similar to the input XML document are accumulated in the XML cache 201 (Yes in step S13), the XML differential compression processing unit 122 determines from the input XML document and similar XML documents similar thereto. A ΔXML document obtained by differentially compressing the input XML document is generated (step S14). Then, the data adding unit 123 adds information indicating the XSLT document associated with the input XML document and the hash value of the similar XML document to the generated ΔXML document, and adds this to the Δ-XSLT converting unit 103. (Step S15).

  Incidentally, the input XML document (contents) and the similar XML document (contents) may be the same. In this case, the content of the ΔXML document is, for example, null or the input XML document and the similar XML document. And the like indicating that they are the same.

  On the other hand, when a similar XML document similar to the input XML document is not accumulated in the XML cache 201 (No in step S13), the input XML document is transmitted to the Δ-XSLT conversion unit 103 (step S16).

  In this case, the cache management unit 121 caches (registers) the input XML document in the XML cache 201 in association with the hash value before or after this. For example, a hash value (for example, fingerprint) of the input XML document is obtained, and the input XML document is cached in the XML cache 201 using the hash value as a label (step S17).

  FIG. 8 shows a configuration example of the Δ-XSLT conversion unit 103.

  As illustrated in FIG. 8, the Δ-XSLT conversion unit 103 includes an initial / difference determination unit 131, an initial conversion unit 132, and a difference conversion unit 133. Further, an XSLT / XSLTp correspondence table (303), an XSLT / XSLTd correspondence table (302), an XSLTd cache (202), an HTMLp cache (203), and an XML / XSLT / HTMLp correspondence table (301), which will be described later, are included. 11).

  The input from the ΔXML generation unit 102 to the Δ-XSLT conversion unit 103 is an input XML document (when there is no XML document similar to the XML cache), or information indicating a XSLT document associated with the input XML document and a similar XML document This is a ΔXML document to which the hash value is added (when there is an XML document similar to the XML cache).

  FIG. 9 shows an example of the processing procedure of the Δ-XSLT conversion unit 103.

  First, in step S21, the initial / difference determining unit 131 checks whether an XML document (input XML document) or a ΔXML document is input. If an XML document is input, the hash value of the XML document is determined. If a ΔXML document is obtained, the hash value of the similar XML document added to the ΔXML document is extracted. Also, the corresponding XSLT document is input and its hash value is obtained.

  In order to distinguish whether a certain document is an XML document or a ΔXML document, for example, information indicating the type of the document is explicitly included in the document (for example, an attribute of a specific root element). As a value). Alternatively, whether or not information unique to a certain type of document exists in the document may be used as a criterion (for example, if a hash value of a similar XML document is included, the document is determined to be a ΔXML document and must be included) For example, it is determined as an XML document).

  Next, in step S22, from the correspondence table (XML / XSLT / HTMLp correspondence table) in which the hash value of the XML document (similar XML document), the hash value of the XSLT document, and the hash value of the HTMLp document are registered in association with each other, A pair of the hash value of the XML document obtained in S21 and the hash value of the XSLT document is searched.

  FIG. 10 shows an example of an XML / XSLT / HTMLp correspondence table.

  If the search is not hit in step S23, a new XSLT transformation is performed. Therefore, the input XML document or the ΔXML document and the XSLT document are transmitted to the initial conversion unit 132, and the initial conversion process in step S24 is performed.

  On the other hand, if the search is hit in step S23, since there is a history of XSLT conversion for the similar XML document, the ΔXML document and the XSLT document are transmitted to the difference conversion unit 133, and the difference conversion process in step S25 is performed.

  Hereinafter, the initial XSLT conversion will be described in detail.

  The initial conversion unit 132 performs normal XSLT conversion on the input XML document to generate a corresponding HTML document, and the difference XSLT conversion that can be generated in the next time and that makes the input XML document a similar XML document. The information necessary for this is generated and cached.

  FIG. 11 shows a configuration example of the initial conversion unit 132.

  As illustrated in FIG. 11, the initial conversion unit 132 includes an XML decompression unit 1321, an XSLTp generation unit 1323, an XSLTd generation unit 1322, an XSLT conversion unit 1324, and an xpath removal filter 1325.

  The XML cache 201 is the XML cache 201 (see FIG. 6) of the ΔXML generation unit 102.

  The input to the initial conversion unit 132 is an XML document or ΔXML document and an XSLT document.

  First, the XML decompression unit 1321 performs decompression processing on the XML document or the ΔXML document.

  FIG. 12 shows a configuration example of the XML decompression unit 1321.

  As shown in FIG. 12, the XML decompression unit 1321 includes a cache management unit 13211 and an XML differential decompression processing unit 13212.

  FIG. 13 shows an example of the processing procedure of the XML decompression unit 1321.

  First, the cache management unit 12311 checks whether an XML document (input XML document) or a ΔXML document has been input, and if an XML document has been input (step S31), obtains a hash value of the XML document ( In step S35, the hash value is associated with the XML document and registered in the XML cache 201 (step S36). The XML document is output as it is.

  If a ΔXML document has been input (step S31), a hash value of a similar XML document added to the ΔXML document is extracted (step S32). Next, the XML cache 201 is searched using the extracted hash value of the similar XML, and the base similar XML is extracted (step S33). Then, data expansion is performed based on the extracted similar XML document and ΔXML document, and the original XML document is restored (step S34). Then, the restored XML document is output.

  Next, in the present embodiment, the XSLT document generation unit 1322 and the XSLTp generation unit 1323 perform data conversion on the XSLT document input to the initial conversion unit 132, respectively.

  The XSLTd unit 1322 performs data conversion on the XSLT document to generate an XSLTd document used for differential XSLT conversion.

  Here, the meta XSLT document will be described.

  Since the XSLT document is described in the grammar of the XML document, the structure of the XSLT document itself can be converted by another XSLT document. That is, a new function can be added to the XSLT document to be converted by the other meta XSLT document. In this way, an XSLT document that converts an XSLT document and generates an XSLT document having a new function is referred to as a meta XSLT document.

  For example, an XSLTp document is an HTML document that is output by converting an XML document using the XSLTp document, and includes an instruction statement for embedding information indicating a conversion source XML node (current node) at the time of output in all HTML elements. This is an XSLT document added to the original XSLT document. In other words, the meta XSLT document in this case is one in which the above-mentioned command statement is added to the original XSLT document (xpath embedding meta XSLT document).

  Similarly, the XSLTd document is an XSLT document in which a command statement for copying the xpath attribute of the XML document to the converted HTML element is added to the original XSLT document. In other words, the meta XSLT document in this case is one in which the above-mentioned command statement is added to the original XSLT document (difference node information migration meta XSLT document).

  In this embodiment, one meta XSLT document may be used for general purposes for generating XSLTp and one for general use for generating XSLTd. There is no need to prepare).

  14 shows an example of an XML document, FIG. 15 shows an example of an XSLT document, FIG. 16 shows an example of a meta XSLT document (in the case of a meta XSLT document that generates an XSLTp document from an XSLT document), and FIG. 17 shows an example of an XSLTp document. FIG. 18 shows an example of the XSLTd document.

  FIG. 19 shows a configuration example of the XSLTd generation unit 1322.

  As illustrated in FIG. 19, the XSLTd generation unit 1322 includes an XSLT conversion unit 13221 and a difference node information migration meta XSLT holding unit 13222 that holds a difference node information migration meta XSLT document. The method of holding the difference node information migration meta-XSLT document is not particularly limited, and may be, for example, an independent file or may be incorporated in a program.

  As shown in FIG. 20, an XSLTd document is converted from a pseudo XML document to a pseudo HTML document when a pseudo HTML document (described later) is generated by performing XSLT conversion using the XSLTd document on the pseudo XML document (described later). And a function for transmitting the difference operator and the node information of the original XML are added to the original XSLT document.

  The XSLT conversion unit 13221 of the XSLTd generation unit 1322 generates an XSLTd document by performing XSLT conversion on the XSLT document using the meta-XSLT document for difference node information migration.

  The XSLTd generation unit 1322 obtains the hash value of the generated XSLTd document, associates the hash value of the original XSLT document with the hash value of the XSLTd document, registers the hash value in the XSLT / XSLTd correspondence table 302, and generates the hash value The XSLTd document is cached in the XSLTd cache 202 in association with the hash value.

  FIG. 21 shows an example of the XSLT / XSLTd correspondence table 302.

  Any method other than the method using the meta XSLT document may be used as long as the pseudo HTML document can hold the difference operator of the pseudo XML document and the original XML node information.

  FIG. 20 is an example, and the difference operator and the original XML node information may not be the descriptions shown in FIG.

  On the other hand, the XSLTp generation unit 1323 converts the data of the XSLT document to generate an XSLTp document used for the first time XSLT conversion.

  FIG. 22 shows a configuration example of the XSLTp generation unit 1323.

  As illustrated in FIG. 22, the XSLTp generation unit 1323 includes an XSLT conversion unit 13231 and an xpath embedding meta XSLT holding unit 13232 that holds an xpath embedding meta XSLT document. Note that the method of holding the xpath embedding meta-XSLT document is not particularly limited, and may be, for example, an independent file or may be incorporated in a program.

  As shown in FIG. 23, an XSLTp document is obtained by applying a meta XSLT document to an original XSLT document, and an XSLT transformation using the XSLTp document is performed on the XML document to generate an HTMLp document. A function for embedding node information of an XML document corresponding to an HTML node output by conversion is added to the original XSLT. As described above, an HTML document in which node information of an XML document is embedded is referred to as an HTMLp document.

  The XSLT conversion unit 13231 of the XSLTp generation unit 1323 generates an XSLTp document by performing XSLT conversion on the XSLT document using the xpath embedding meta XSLT 13232.

  The XSLTp generation unit 1323 obtains the hash value of the generated XSLTp document, registers the hash value of the original XSLT document and the hash value of the XSLTp document, and registers them in the XSLT / XSLTp correspondence table 303.

  FIG. 24 shows an example of the XSLT / XSLTp correspondence table 303.

  Any method other than the method using the meta XSLT document may be used as long as the HTML node output by XSLT conversion can hold the node information of the XML document corresponding to the node.

  Further, FIG. 23 is an example, and the notation of the node information of the XML document may be different from that of FIG.

  Next, the XSLT conversion unit 1324 generates an HTMLp document by converting the XML document output from the XML decompression unit 1321 using the XSLTp document output from the XSLTp generation unit 1323.

  At this time, the XSLT conversion unit 1324 obtains the hash value of the generated HTMLp document, generates the hash value of the XML document, the hash value of the XSLT document corresponding to the XSLTp document obtained from the XSLT / XSLTp correspondence table 303, and the generation The hash value of the HTMLp is associated and added to the XML / XSLT / HTMLp correspondence table 301 (see FIG. 10). The generated HTMLp document is cached in the HTMLp cache 203 in association with the hash value.

  Next, the generated HTMLp document is subjected to an xpath removal filter 1325 to remove xpath.

  As shown in FIG. 25, the xpath removal filter 1325 deletes the original XML node information in the XSLT transformation that has generated the HTMLp document of the HTMLp document of (a) to obtain the HTML document of (b). . The deletion method is not particularly limited, and for example, XSLT may be used or a replacement process may be used.

  The generated HTML is transmitted to the browser 105 and displayed on a display screen (not shown).

  Hereinafter, the case where a document similar to the input XML document is cached for each module will be mainly described. For example, this applies to a case where editing is performed on a cached XML document by using an editor.

  Here, as an example, it is assumed that an edited XML document as shown in (b) is obtained by performing an editing operation on the XML document (cached XML document) shown in FIG. To do. This editing example corresponds to the work of adding a data element having the second value of “1.5” in the root element which is the document root.

  Further, it is assumed that the XML document before and after editing uses the XSLT document shown in FIG. 27 as a style sheet.

  The differential XSLT conversion and the like will be described using these as specific examples.

  First, when an edited XML document (FIG. 26B) and an XSLT document associated with the XML document (FIG. 27) are input, the XSLT determination unit 101 performs ΔS as in the case before the XML editing work. -Determine whether or not XSLT conversion is possible.

  In this specific example, it is assumed that the XSLT document is determined to be an XSLT that can be subjected to Δ-XSLT conversion. As a result, the XML document is transmitted to the ΔXML conversion unit 102, and the XSLT document is transmitted to the Δ-XSLT conversion unit 103.

  Here, it is assumed that the XML document before editing (FIG. 26A) is cached in the XML cache 201 and searched for as a similar XML document.

  In this case, the ΔXML conversion unit 102 generates a ΔXML document that is a difference between the XML document in FIG. 26B and the XML document in FIG. As described above, the ΔXML document includes, for example, difference operators (insertion, deletion, etc.) and information on the target node.

  FIG. 28 shows a specific example of a ΔXML document indicating a difference corresponding to the editing work shown in FIG. In this specific example, <data> 1.5 </ data> is inserted at the position of / child :: node [1] / child :: node [2] with respect to the similar XML document (FIG. 26A). (And an input XML document is obtained). Of course, FIG. 28 is an example, and other notations may be used.

  The generated ΔXML document is transmitted to the Δ-XSLT conversion unit 103.

  An example of the processing procedure of the Δ-XSLT conversion unit 103 is as shown in FIG.

  In the case of this specific example, assuming that a similar XML document (contents before editing) is cached in the XML / XSLT / HTMLp correspondence table 301 (see FIG. 10), according to the procedure example of FIG. 9, Δ-XSLT In the conversion unit 103, Yes in step S23, and differential XSLT conversion is performed in step S25.

  Hereinafter, the differential XSLT conversion will be described in detail.

  The difference conversion unit 133 receives the ΔXML document and the XSLT document associated therewith. The difference conversion unit 133 includes a ΔHTMLp document obtained by performing XSLT conversion using a XSLTd document corresponding to the XSLT document on the pseudo XML document generated from the ΔXML document, and a similar XML document (in this specific example, From the HTMLp document corresponding to the XML document before editing), an HTML document corresponding to the XML document (in this specific example, the edited XML document) that is the basis of the ΔXML document is generated.

  As described above, the HTMLp document is an HTML document in which node information of the XML document is embedded. The same applies to ΔHTMLp documents (described later).

  FIG. 29 shows a configuration example of the difference conversion unit 133.

  As illustrated in FIG. 29, the difference conversion unit 133 includes a pseudo XML generation unit 1331, a ΔHTML extraction unit 1332, an HTML decompression unit 1333, an XSLT conversion unit 1334, and an xpath removal filter 1335.

  Note that the xpath removal filter 1325 of the initial conversion unit 132 and the xpath removal filter 1335 of the difference conversion unit 133 may be the same.

  Also, the XSLT conversion unit 104, the XSLT conversion unit 1324 of the initial conversion unit 132 of the Δ-XSLT conversion unit 103, the XSLT conversion unit 13221 of the XSLTd generation unit 1322 of the initial conversion unit 132, and the XSLTp generation unit of the initial conversion unit 132 All or part of the 1323 XSLT conversion unit 13231 may be used in common.

  FIG. 30 shows an example of the procedure of difference conversion processing.

  First, in step S41, a hash value of an XML document that is added to the ΔXML document and becomes a difference base, that is, a similar XML document is obtained. In step S42, a hash value of the XSLT document is obtained. Next, in step S43, the XML / XSLT / HTMLp correspondence table 301 is searched using those hash values, and the corresponding HTMLp document (base HTMLp document) (hash value) is specified from the HTMLp cache 203. To do.

  On the other hand, the ΔXML document is transmitted to the pseudo XML generation unit 1331. In step S44, the pseudo XML generation unit 1331 generates a pseudo XML document that reproduces the XML structure from the node information of the original XML document that the ΔXML document has.

  The pseudo XML document is an XML document imitating the structure of the original XML data, and includes difference information (operator, node information, etc.). In this specific example, the pseudo XML document shown in FIG. 31B is generated from the ΔXML document shown in FIG.

  In step S45, based on the hash value of the XSLT document input to the difference conversion unit 133, the corresponding XSLTd hash value for difference conversion is obtained from the XSLT / XSLTd correspondence table 302, and the hash of the XSLTd is obtained. Based on the value, the corresponding XSLTd is retrieved from the XSLTd cache 202.

  Next, in step S46, the XSLT conversion unit 1334 performs XSLT conversion on the generated pseudo XML document using the extracted XSLTd document, thereby generating a pseudo HTMLp document.

  The pseudo HTMLp document is one HTML document. For example, the node affected by the editing operation has the feature that the editing information (information of the operator and the original XML node) is recorded. In this specific example, the pseudo HTMLp document of (b) is generated from the pseudo XML document of FIG. 32 (a).

  Next, in step S47, the ΔHTMLp extraction unit 1332 extracts nodes having editing information from the pseudo HTMLp document to create a ΔHTMLp document. In this specific example, the ΔHTMLp document of (b) is generated from the pseudo HTMLp document of FIG. 33 (a). Note that FIG. 33B is an example, and ΔHTMLp may be expressed in other formats.

  Therefore, in step S48, the ΔHTMLp document and the previous HTMLp document (base HTMLp document) are input to the HTML decompression unit 1333, and the HTML decompression unit 1333 stores the node information of the original XML document that the ΔHTMLp document and the HTMLp document have. Is used to decompress an HTML document.

  FIG. 34 shows an example of decompression processing for the data of FIG. In this example, the HTML document (c) is obtained from the ΔHTMLp document (a) and the HTMLp document (base HTMLp document) (b).

  Finally, in step S49, as in the case of the first conversion, the xpath removal filter 1325 deletes the original XML node information from the HTMLp document generated by the decompression process (corresponding to the input XML document). An HTML document (with the same content as the HTML document obtained by applying the XSLT document) is generated.

  This HTML document is transmitted to the browser 105.

  In the above, it is also possible to cache the edited XML document, XSLT document, HTMLp document, and XSLTd document that have undergone the difference conversion, and use them as a basis for the subsequent difference conversion.

  According to this embodiment, when there is an HTML document corresponding to a similar XML document similar to the input XML document, the difference between the input XML document and the similar XML document is subjected to XSLT conversion instead of XSLT conversion of the input XML document. Since the HTML document corresponding to the input XML document can be obtained from the HTML document corresponding to the similar XML document, the XSLT conversion processing can be reduced.

  Hereinafter, the case where the structured document conversion apparatus according to the present embodiment is used in combination with a Web proxy cache will be described.

  The structured document conversion apparatus according to the present embodiment can construct an effective system by combining with the Web cache technology.

  Here, a case where the fingerprint cache (hereinafter referred to as “FP cache”) technology disclosed in JP-A-2002-268935, JP-A-2003-268936, and JP-A-2003-268937 is used together will be described as an example.

  The fingerprint cache technique is a technique for reducing the data transfer amount between the server and the client by using the FP value (hash value) of the content.

  The FP cache technology includes a dual proxy version in which a proxy module in which an FP cache is mounted on both the server side and the client side, and a client version FP cache in which an FP cache is mounted with the client side as a browser plug-in.

  FIG. 35 shows the basic information flow of XML and XSLT on the Web. Each device is connected via a network such as the Internet or a LAN.

  When an XML GET request is issued from the client (device) 1210 to the Web server 1200 (device), the Web server 1200 responds with the XML. Further, the client 1210 issues a GET request for the XSLT document used for the XML, and the Web server 1200 responds with the XSLT document.

  Here, as an example, a communication system is constructed as shown in FIG. 36 using the technology of the plug-in version FP cache. Each device is connected via a network such as the Internet or a LAN. The difference from FIG. 35 is that the plug-in 1401 exists in the client 1400 (device) and that the server-side proxy 1300 (device) exists between the Web server (device) 1200 and the client 1400. Note that the system can also be realized by using a technique other than the plug-in version FP cache.

  FIG. 37 shows a configuration example of the server side proxy 1300.

  The configuration and operation of the server-side proxy 1300 will be described with reference to FIG.

  The server side proxy 1300 receives the XML document and the XSLT document from the Web server 1200.

  For the XSLT document, an XSLT-FP compression unit 1301 that performs differential compression using a compression technique similar to a known FP cache and a Web cache 1302 that caches the XSLT document are implemented. As a result, the XSLT document is appropriately compressed and transferred from the server side proxy 1300 to the client 1400.

  For the XML document, the ΔXML generation unit 102 and the XML cache 201 described so far are mounted. An XML document (also referred to as a transfer target XML document) and an XSLT document received from the Web server 1200 are received. When an XML document similar to the transfer target XML document is cached in the XML cache 201 (that is, when the transfer target XML document is an XML document similar to the XML document already cached in the XML cache 201), The ΔXML generation unit 102 creates the difference information as a ΔXML document. At this time, information indicating the XSLT document associated with the similar XML document is also embedded in the ΔXML document. When there is no XML document similar to the XML cache 201, the transfer target XML document is transmitted to the client 210 and cached in the XML cache 201. As a result, the XML document or the ΔXML document is transferred from the server side proxy 1300 to the client 1400.

  FIG. 38 shows a configuration example of the client 1400.

  FIG. 39 shows an example of the processing procedure of the client 1400.

  The configuration and operation of the client 1400 will be described with reference to FIG.

  The client 1400 (the plug-in 1401) includes an XSLT decompression unit 1411 that decompresses corresponding to differential compression using a compression technique similar to that of a known FP cache, an XSLT cache 1412 that caches an XSLT document, and the initial conversion unit 132 described above. The XML decompression unit 1413 having the same function as the XML decompression unit 1321, the XML cache 1414 that caches the XML document, the XSLT determination unit 101, the Δ-XSLT conversion unit 103, and the XSLT conversion unit 104 described so far are mounted.

  In the client 1400, first, the XSLT document received from the server side proxy 1300 is decompressed by the XSLT decompression unit 1411 (step S51). Since the XSLT document is compressed with the conventional FP cache technology, the client 1400 also decompresses with the FP cache technology.

  Next, the XSLT determination unit 101 determines whether or not the expanded XSLT document can be subjected to Δ-XSLT conversion (step S52).

  If the XSLT document cannot be Δ-XSLT converted, the Δ-XSLT conversion cannot be used, so the received XML information is expanded. Since the XML document is compressed by the ΔXML generation unit 102, the XML document is expanded using the XML expansion unit 1413 (see FIG. 12) (step S54).

  The expanded XSLT document and the expanded XML document are transmitted to the XSLT conversion unit 104, and enter the normal XSLT conversion process (step S55). An HTML document generated by XSLT conversion of these is transferred to a browser (not shown).

  On the other hand, if the XSLT document can be subjected to Δ-XSLT conversion, Δ-XSLT is entered (step S53).

  First, similarly to the processing flow shown in FIG. 8, the initial / difference determining unit 131 of the Δ-XSLT converting unit 103 determines whether the initial conversion or the differential conversion. For the determination, the XML, XSLT, and HTMLp correspondence table 301 of FIG. 10 is used. If already registered, it is transmitted to the difference conversion unit 133 and the difference conversion process is started. If it is not registered, it is transmitted to the initial conversion unit 132 and the initial conversion process is started. An HTML document is generated in the same manner as already described. Then, the generated HTML document is transferred to a browser (not shown).

  According to this embodiment, since the data transmission of the XML document and the XSLT document is only the transmission of the difference data between the server and the client, the transfer amount can be reduced, and the transfer over the network using a thin line is possible. Can reduce the time it takes. Moreover, since the XSLT conversion is performed with the difference data, the processing cost can be reduced.

  In the above, in the present embodiment, the case where an HTML document is generated by performing XSLT conversion using an XSLT document as an XML document as a structured document has been described as an example. However, when an XML document is converted into another XML document The present invention can also be applied to the case of converting to a structured document other than an HTML document. The present invention can also be applied to a case where a structured document other than an XML document is converted into an XML document, an HTML document, or another structured document.

Each of the above functions can be realized even if it is described as software and processed by a computer having an appropriate mechanism.
The present embodiment can also be implemented as a program for causing a computer to execute a predetermined procedure, causing a computer to function as a predetermined means, or causing a computer to realize a predetermined function. In addition, the present invention can be implemented as a computer-readable recording medium on which the program is recorded.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 is a diagram illustrating a configuration example of a structured document processing apparatus according to an embodiment of the present invention. The figure for demonstrating the XSLT determination part which concerns on the same embodiment The flowchart which shows an example of the process sequence of the XSLT determination part which concerns on the embodiment The figure for demonstrating the XSLT conversion part which concerns on the same embodiment The figure for demonstrating the differential XSLT conversion which concerns on the same embodiment The figure which shows the structural example of the (DELTA) XML production | generation part which concerns on the same embodiment. The flowchart which shows an example of the process sequence of the (DELTA) XML production | generation part which concerns on the embodiment The figure which shows the structural example of the (DELTA) -XSLT conversion part which concerns on the same embodiment. The flowchart which shows an example of the process sequence of the (DELTA) -XSLT conversion part which concerns on the embodiment The figure which shows an example of the XML / XSLT / HTMLp correspondence table according to the embodiment The figure which shows the structural example of the first time conversion part which concerns on the same embodiment The figure which shows the structural example of the XML expansion | extension part which concerns on the embodiment A flowchart showing an example of an XML decompression unit processing procedure according to the embodiment A diagram showing an example of an XML document according to the embodiment FIG. 4 is a diagram showing an example of an XSLT document according to the embodiment. FIG. 4 is a diagram showing an example of a meta XSLT document according to the embodiment. FIG. 4 is a diagram showing an example of an XSLTp document according to the embodiment. FIG. 4 is a diagram showing an example of an XSLTd document according to the embodiment. The figure which shows the structural example of the XSLTd production | generation part which concerns on the same embodiment FIG. 6 is a diagram for explaining conversion from an XSLT document to an XSLTd document by the meta-XSLT document for difference node information migration according to the embodiment and conversion from a pseudo XML document to a pseudo HTML document by the XSLTd document. The figure which shows an example of the XSLT and XSLTd correspondence table which concerns on the embodiment The figure which shows the structural example of the XSLTp production | generation part which concerns on the same embodiment FIG. 6 is a diagram for explaining conversion from an XSLT document to an XSLTp document by an xpath embedding meta-XSLT document according to the embodiment, and conversion from an XML document to an HTMLp document by the XSLTp document. The figure which shows an example of the XSLT * XSLTp correspondence table which concerns on the same embodiment 8 is a flowchart showing an example of the procedure of xpath removal filter processing by the xpath removal filter according to the embodiment. The figure for demonstrating an example of the edit of the XML document which concerns on the embodiment FIG. 4 is a diagram showing an example of an XSLT document associated with an XML document according to the embodiment. FIG. 5 is a diagram showing an example of a ΔXML document according to the embodiment. The figure which shows the structural example of the difference conversion part which concerns on the same embodiment The flowchart which shows an example of the procedure of the difference conversion process which concerns on the same embodiment FIG. 6 is a diagram for explaining processing for generating a pseudo XML document from a ΔXML document according to the embodiment. FIG. 6 is a view for explaining processing for generating a pseudo HTMLp document from a pseudo XML document according to the embodiment. The figure for demonstrating the process which produces | generates (DELTA) HTMLp document from the pseudo | simulated HTMLp document which concerns on the embodiment The figure for demonstrating an example of the expansion | extension process which concerns on the embodiment A diagram for explaining a basic information flow of an XML document and an XSLT document between a general client and a Web server 2 is a diagram illustrating a configuration example of a communication system including a client, a server-side proxy, and a Web server according to the embodiment. The figure which shows the structural example of the server side proxy which concerns on the same embodiment A diagram showing a configuration example of a client according to the embodiment A flowchart showing an example of a processing procedure of a client according to the embodiment

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... XSLT determination part, 102 ... (DELTA) XML production | generation part, 103 ... (DELTA) -XSLT conversion part, 104 ... Normal XSLT conversion part, 105 ... Browser, 121,12311 ... Cache management part, 122 ... XML difference compression process part, 123 ... Data Addition unit, 131 ... first time / difference determination unit, 132 ... first time conversion unit, 133 ... difference conversion unit, 201, 1414 ... XML cache, 202 ... cache for XSLTd, 203 ... cache for HTMLp, 301 ... compatible with XML / XSLT / HTMLp Table ... 302 ... XSLT / XSLTd correspondence table, 303 ... XSLT / XSLTp correspondence table, 1321 ... XML decompression unit, 1323 ... XSLTp generation unit, 1322 ... XSLTd generation unit, 1324, 13221, 13231, 1334 ... XSLT conversion unit, 1325 133 5 ... xpath removal filter, 13212 ... XML differential decompression processing unit, 13222 ... difference node information migration meta XSLT holding unit, 13232 ... xpath embedding meta XSLT holding unit, 1331 ... pseudo XML generation unit, 1332 ... ΔHTML extraction unit, 1333 ... HTML decompression unit, 1200 ... Web server, 1210,1400 ... Client, 1300 ... Server side proxy, 1401 ... Plug-in, 1301 ... XSLT-FP compression unit, 1302 ... Web cache, 1411 ... XSLT decompression unit, 1412 ... XSLT cache , 1413 ... XML extension part

Claims (13)

First storage means for storing a first structured document;
A style sheet for converting the structure of the structured document, wherein the first structured document is converted based on a style sheet associated with the first structured document to generate a second structured document First generating means to:
Second storage means for storing the second structured document generated by the first generation means;
A third structured document and a first structured document stored in the first storage unit and associated with the same style sheet as the style sheet associated with the third structured document; Second generation means for generating a difference structured document indicating a difference between the two,
Third generation means for converting the difference structured document based on the style sheet associated with the third structured document and generating a converted difference structured document;
The converted difference structured document generated by the third generation unit and the first structured document that is the basis of the difference structured document are converted based on the style sheet by the first generation unit. Based on the second structured document obtained in this way, a fourth structured document corresponding to the structured document obtained by converting the third structured document with the style sheet is generated. A structured document processing apparatus comprising: a fourth generation unit. The first storage means stores the first structured document and first identification information for identifying the first structured document in association with each other.
The second storage means stores the second structured document in association with second identification information for identifying the second structured document;
For the second structured document stored in the second storage unit, the structured document processing device stores the second identification information of the second structured document and the second structured document. The first identification information of the first structured document that has been generated is associated with the third identification information that identifies the style sheet used to generate the second structured document. And further comprising third storage means for storing,
The fourth generation unit is configured to perform the first generation based on the first identification information of the first structured document that is the basis of the difference structured document and the third identification information of the style sheet. Second identification information of the second structured document is obtained from the third storage means, and the second structured document is obtained from the second storage means based on the second identification information. The structured document processing apparatus according to claim 1. Whether the fourth structured document can be generated by the second, third, and fourth generation means for the third structured document is associated with the third structured document. And a determination means for determining based on the style sheet,
2. The structured document processing apparatus according to claim 1, wherein when the determination unit determines that the determination is possible, the generation is performed by the second, third, and fourth generation units.   2. The apparatus according to claim 1, further comprising means for converting the third structured document by a style sheet associated with the third structured document when the determining means determines that the third structured document is not possible. 3. The structured document processing apparatus according to 3. Whether the fourth structured document can be generated by the second, third, and fourth generation means for the third structured document is associated with the third structured document. And a determination means for determining based on the style sheet,
It said second generating means, prior to the determination by the determining means, to generate a pre-Symbol differencing structured document,
The structured document processing apparatus according to claim 1, wherein the generation is performed by the third generation unit and the fourth generation unit, respectively, when it is determined by the determination unit.   The original third structure restored based on the difference structured document and the first structured document generated by the second generating means when it is determined by the determining means that it is not possible 6. The structured document processing apparatus according to claim 5, further comprising means for converting the structured document by a style sheet associated with the third structured document.   The second generation unit uses the first structured document similar to the third structured document among the first structured documents stored in the first storage unit, and uses the first structured document. The structured document processing apparatus according to claim 1, wherein the structured document is generated. A means for inputting a structured document;
When a structured document similar to the input structured document is stored in the first storage means, the input structured document is processed and stored as the third structured document. 2. The structured document processing apparatus according to claim 1, wherein, if not, the inputted structured document is processed as the first structured document.   2. The structured document processing apparatus according to claim 1, further comprising means for displaying the fourth structured document generated by the fourth generating means on a display screen.   2. The structured document processing apparatus according to claim 1, wherein the second to fourth generation units are provided in the same apparatus.   2. The structured structure according to claim 1, wherein the second generation unit is provided in a first device, and the third and fourth generation units are provided in a device different from the first device. Document processing device. A structured document processing method for a structured document processing apparatus, comprising:
First storage means provided in the said structured document processing apparatus, a first storage step of memorize the first structured document,
A first generation unit included in the structured document processing apparatus is a style sheet for converting the structure of the structured document, and the first structure is based on a style sheet associated with the first structured document. A first generation step of converting the structured document to generate a second structured document;
Second storage means provided in the said structured document processing apparatus, a second storage step of memorize the second structured document generated by said first generating means,
The second generation means included in the structured document processing apparatus is the same as the third structured document and the style sheet associated with the third structured document stored in the first storage means. A second generation step of generating a difference structured document indicating a difference from the first structured document associated with the style sheet;
Third generation means included in the structured document processing apparatus converts the differential structured document based on the style sheet associated with the third structured document, and generates a converted differential structured document. A third generation step;
The fourth generation unit included in the structured document processing apparatus includes the converted differential structured document generated by the third generating unit and the first structured source that is the basis of the differential structured document. Obtained by converting the third structured document using the style sheet based on the second structured document obtained by converting the document based on the style sheet by the first generating means. A structured document processing method, comprising: a fourth generation step of generating a fourth structured document corresponding to the structured document. In a program for causing a computer to function as a structured document processing apparatus,
The program is
A first storage step of storing a first structured document in a first storage means;
A style sheet for converting the structure of the structured document, wherein the first structured document is converted based on a style sheet associated with the first structured document to generate a second structured document A first generating step,
A second storage step of storing the second structured document generated by the first generation step in a second storage means;
A third structured document and a first structured document stored in the first storage unit and associated with the same style sheet as the style sheet associated with the third structured document; A second generation step of generating a difference structured document indicating the difference between;
A third generation step of converting the differential structured document based on the style sheet associated with the third structured document to generate a converted differential structured document;
The converted difference structured document generated by the third generation step and the first structured document that is the basis of the difference structured document are converted based on the style sheet by the first generation step. Based on the second structured document obtained in this way, a fourth structured document corresponding to the structured document obtained by converting the third structured document with the style sheet is generated. A program for causing a computer to execute the fourth generation step.

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