JP2010267092A - Information processor and information processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology to improve the conversion efficiency from text XML containing large-size text data as attribute values or content of element, into binary XML. <P>SOLUTION: An information processor includes: a means for acquiring a structured document in a text format; a means for analyzing the structured document and detecting the text data; and a generation means for converting the structured document by converting the text data into slave elements and for generating a structured document in a binary format based on the converted structured document. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for processing a structured document.

  Until now, the format of XML data was generally a text format. However, since XML data requires redundant data to represent the data structure, and it takes time for a computer to read and write, binary XML technology has attracted attention in recent years.

  For example, there is Efficient XML Interchange (htt: //www.w3.org/XML/EXI/) as a standard specification of W3C. Further, as a standard specification of ISO, there is Fast Infoset (https://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=41327&scopelist=PROGRAMME).

  With these technologies, it is possible to reduce the data size by encoding each vocabulary such as an element name and an attribute name included in XML data in the order of appearance in the XML data. A table indicating the correspondence between codes and vocabularies is called a coding table. Binary XML format data could be read and written faster than conventional text format XML data.

  In addition, the data size can be further reduced by encoding attribute values and element contents using integer type, floating point type, or proprietary compression algorithms instead of conventional string data. Met. Further, when analyzing these data, it is not necessary to perform conversion processing from character string data to numerical data by a conventional application, so that the processing time required for the analysis can be further shortened.

  In addition, the document structure of XML data and the data types of the included attribute values and element content values could be defined using a schema. In general, these schemas are used to verify the document structure of XML data and whether the data type of values exactly matches the schema definition. As a standard specification of the W3C schema, there is XML Schema (https://www.w3.org/XML/Schema). As a standard specification of the ISO schema, there is RELAX NG (https://www.oasis-open.org/committees/relax-ng/).

  Another technique using a schema is data binding. This is to reduce the development cost of an application by automatically generating a class file for storing XML data from a schema at the time of development and using the class at the time of execution. When binding XML data to a class generated from a schema, the included text data is converted based on each data type defined in the schema and stored in each member. Therefore, unlike a conventional text-based XML parser, an application can handle text data included in XML data as a value of each data type by using a class generated from a schema. Generally, JAXB (https://jaxb.dev.java.net/) of Sun Micorsystems and Relaxer (https://www.relaxer.jp/) are used.

  In addition, KDDI's XEUS can efficiently compress XML data by encoding each numerical value for an array of numerical values separated by commas in attribute values and element contents. there were.

  In addition, there is one that automatically generates a conversion style sheet between a plurality of XML data having different document structures by using schema information (Patent Document 1). In addition, in order to improve the access efficiency from an application to XML data, there is one that converts tag names so that the hierarchical structure included in the XML data becomes shallow (Patent Document 2).

JP-A-2005-352945 JP 2002-297469 A

  In conventional binary XML, if text data of a large size is included in attribute values or element contents, it is difficult to reduce the data size because the compression efficiency is not good even if encoded in binary XML format. It was.

  Here, text format XML data (FIG. 1A) describing a graphic object (FIG. 1B) using W3C standard SVG will be described. Even if this XML data in text format is encoded in binary XML format, the value of the d attribute of the path element is encoded as text data as it is and stored in the character string table in the binary XML data. Therefore, it has been difficult to efficiently compress large-size text data that is unlikely to appear repeatedly in XML data, even using conventional binary XML technology. In particular, in SVG, it is often difficult to obtain a compression effect by binary XML because graphic objects are often described using long text data as the value of the d attribute of the path element.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for improving the conversion efficiency from text XML including binary text data as attribute values or element contents to binary XML. To do.

  In order to achieve the object of the present invention, for example, an information processing apparatus of the present invention comprises the following arrangement. A means for obtaining a structured document in text format; a means for analyzing the structured document to detect text data; and converting the structured document by converting the text data into child elements; And generating means for generating a structured document in binary format based on the structured document.

  With the configuration of the present invention, it is possible to improve the conversion efficiency from text XML including large text data as attribute values or element contents into binary XML.

The figure which shows the XML data of a text format, and its drawing result. The figure which shows the structural example of the system which concerns on embodiment. The block diagram which shows the hardware structural example of PC101. The processing function block diagram of PC101. The flowchart of the process which PC101 performs. The flowchart which shows the detail of step S113. The figure which shows an example of a partial schema. (A) is a figure which shows the example of an XPath expression, (b) is a figure which shows the XML data of a binary format. The figure which shows the code | symbol of each event. The figure which shows a name table. (A) is a figure which shows a value table, (b) is a figure which shows the table | surface of a code | symbol.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. The embodiment described below shows an example when the present invention is specifically implemented, and is one of the specific examples of the configurations described in the claims.

  In the present embodiment, a technique for converting text XML as a structured document in which an element including an attribute having text data of a relatively large size as an attribute value is written into binary XML with high compression efficiency will be described.

  First, the system according to the present embodiment will be described with reference to FIG. As shown in FIG. 2, the system according to the present embodiment includes a PC (personal computer) 101 as an information processing apparatus according to the present embodiment, a LAN 102 as an example of a network, a digital camera 103, a multifunction peripheral 104, and a file server 105. It is configured.

  The digital camera 103 is for acquiring an image to be used together with the XML data generated by the PC 101 by imaging, and the image data captured by the digital camera 103 is transferred to the PC 101 and the file server 105 via the LAN 102. Of course, the method of using the digital camera 103 is not limited to this.

  The multifunction device 104 is for obtaining an image to be used together with the XML data generated by the PC 101 by copying, and the image data copied by the multifunction device 104 is transferred to the PC 101 and the file server 105 via the LAN 102. Of course, the method of using the multifunction machine 104 is not limited to this.

  The file server 105 holds image data transferred from the digital camera 103 or the multifunction peripheral 104 and also holds XML data transferred from the PC 101. The image data and XML data held by the file server 105 can be appropriately accessed via the LAN 102.

  The PC 101 is used as an information processing apparatus according to the present embodiment, and executes processing to be described later for converting text-format XML data into binary-format XML data. Next, a hardware configuration example of the PC 101 will be described with reference to FIG.

  The CPU 201 controls the entire PC 101 using computer programs and data stored in the ROM 202 and the RAM 203 and executes each process described later as what the PC 101 performs.

  The ROM 202 is an example of a computer-readable storage medium, and stores setting data, a boot program, and the like of the PC 101. The RAM 203 is an example of a computer-readable storage medium, and temporarily stores computer programs and data loaded from the storage unit 204, data received from the outside via the LAN I / F 207, USB I / F 209, and the like. Have an area for The RAM 203 also has a work area used when the CPU 201 executes various processes. That is, the RAM 203 can provide various areas as appropriate.

  The storage unit 204 is an example of a computer-readable storage medium, and is a large-capacity information storage device represented by a hard disk drive device. The storage unit 204 stores an OS (Operating System) and computer programs and data for causing the CPU 201 to execute each process described below as performed by the PC 101. This computer program and data are appropriately loaded into the RAM 203 under the control of the CPU 201 and are processed by the CPU 201.

  The operation unit 205 is configured by a keyboard, a mouse, and the like, and can input various instructions to the CPU 201 when operated by an operator of the PC 101. The display unit 206 is configured by a CRT, a liquid crystal screen, or the like, and can display a processing result by the CPU 201 using an image, text, or the like.

  The LAN I / F 207 is for connecting the PC 101 to the LAN 102, and the PC 101 communicates with a device connected to the LAN 102 via the LAN I / F 207. The USB I / F 209 is for connecting the PC 101 to the USB line 210, and the PC 101 communicates with a device connected to the USB line 210 via the USB I / F 209. Each of the above units is connected to a common bus and can communicate with each other.

  Note that the system configuration and the PC 101 configuration described above are merely examples, provided that the processing described later can be realized and the application using the binary format XML data obtained by the processing described later is possible. Other configurations may be applied.

  Next, an efficient compression encoding process from text format XML data to binary format XML data will be described with reference to FIG. Note that a computer program and data for causing the CPU 201 to execute processing according to the flowchart shown in FIG. Such computer programs and data are appropriately loaded into the RAM 203 under the control of the CPU 201 and are processed by the CPU 201. When the CPU 201 executes processing using the loaded computer program and data, the PC 101 executes each processing described below (processing at each step shown in FIG. 5).

  In the following description, it is assumed that the XML data in the text format to be compression-encoded is the XML data shown in FIG. Of course, the essence of the processing described below is the same for XML data in other text formats.

  First, in step S102, the CPU 201 selects text-format XML data to be compressed and encoded into binary-format XML data. Such selection may be performed by an application running on the PC 101 or may be performed based on a selection instruction input by the operator via the operation unit 205. As described above, it is assumed here that the XML data shown in FIG. 1 has been selected. The XML data includes an element (path element in FIG. 1) including an attribute (d attribute in FIG. 1) having text data that is difficult to compress efficiently (text data that matches the Xpath expression) as an attribute value. It is.

  Next, in step S103, a partial schema describing a data type related to text data that is difficult to compress efficiently and a definition name that is the root of information on the data type are selected, and the partial schema is analyzed. A DOM tree is created in the RAM 203.

  Note that the definition name that is the root of the partial schema and the data type information is displayed on the display unit 206 using the operation unit 205 while the user interface screen for making these selections is displayed. A selection instruction may be input. Alternatively, a partial schema and a definition name that becomes the root of information on the data type may be selected by incorporating them in the application logic in advance.

  As described above, in the present embodiment, the data that is difficult to compress efficiently is the attribute value of the d attribute of the path element in FIG. An example of a partial schema that defines the data type of the d attribute of the path element in FIG. 1 described using RELAX NG will be described with reference to FIG.

  In the partial schema illustrated in FIG. 7, a plurality of data types are described using the define element, but the definition name that is the root of the data type of the value of the d attribute is “SVG.PathData.datatype”. However, in the case of FIG. 7, the definition name selected in step S103 is “SVG.PathData.datatype”.

  Returning to FIG. 5, in step S104, the document structure of the selected partial schema is simplified based on Chapter 4 simplification of the RELAX NG specification. In step S105, text data corresponding to the defined partial schema is selected by using an XPath expression. An example of an XPath expression that expresses the d attribute of all the path elements that appear in the XML data in the text format is as shown in FIG. As for the selection of text data using the XPath expression, a user interface screen for selection is displayed on the display unit 206, and the user inputs a selection instruction using the operation unit 205 while viewing this screen. May be. Further, such selection may be performed by incorporating an XPath expression in the application logic in advance.

  Next, in step S106, the XML data in the text format is analyzed. Such analysis is performed sequentially from the beginning of the XML data in text format. Next, in step S107, it is determined whether or not encoding from text-format XML data to binary-format XML data has been completed. As a result of the determination, when the processing is completed, the present processing is terminated. When the processing is not completed, the processing proceeds to step S108.

  In step S108, it is determined whether text data matching the XPath expression is included in the XML data in text format. If it is included (if it is possible to detect text data that matches the XPath expression from text-format XML data), the process proceeds to step S110. If not, the process proceeds to step S110. Proceed to S109. In step S109, the text-format XML data is encoded as it is into binary-format XML data in the conventional manner.

  In step S110, data that does not match the XPath expression is encoded in the XML data in text format. In the case of the XML data in the text format of FIG. 1, the first start tag svg does not include text data that matches the XPath expression, and is encoded as a start tag as it is. Since the next path element includes the d attribute that matches the XPath expression, the start tag path and the fill, stroke, and stroke-width attributes are encoded. The d attribute that matches the XPath expression and its attribute value are stored in the RAM 203 without being encoded.

  Next, in step S111, it is determined whether or not the text data that matches the XPath expression is an attribute value. As a result of the determination, if the affiliation destination of the text data matching the XPath expression is an attribute value, the process proceeds to step S112. If the affiliation destination of the text data matching the XPath expression is not an attribute value, The process proceeds to step S115.

  In step S112, a start tag is encoded with the attribute name of the attribute value as the destination of the text data that matches the XPath expression as the tag name. In the example of the text format XML data in FIG. 1, since the text data matching the XPath expression belongs to the attribute value and the attribute name is “d”, the start tag <d> having the name “d” is set. Encode.

  Next, in step S113, the text data matching the XPath expression is sequentially analyzed from the top, and the text data is converted into a child element by using the data type information of the selected partial schema.

  Details of the processing in step S113 will be described with reference to FIG. First, in step S202, the internal state in the DOM tree of the partial schema is initialized. Next, in step S203, in order to store the state during the text data analysis, a pointer p pointing to an arbitrary node in the partial schema is initialized to NULL, a pointer value to the first node, or the like.

  Next, in step S204, it is determined whether or not the analysis for the text data matching the XPath expression is completed. If the determination is completed, the process of step S113 ends, and the process proceeds to step S114. On the other hand, if the result of the determination is not complete, the process proceeds to step S205. In the text data analysis process, a blank character included in the text data is used as a delimiter identifier, the text data is divided by this identifier, and analysis is performed for each divided text data.

  In step S205, it is determined whether or not the divided text data is a variable corresponding to the enumerated value defined below the group element of the partial schema. As a result of the determination, if applicable, the process proceeds to step S206; otherwise, the process proceeds to step S207.

  In step S206, the divided text data as a variable corresponding to the enumerated value defined below the group element of the partial schema is encoded into a start tag having the enumerated value as a tag name. When the partial schema shown in FIG. 7 is used, the enumerated values are “M”, “m”, “L”, and “l”. Therefore, the divided text data “M” to be analyzed first is “moveType”. Corresponds to the following define elements that have names. In such a case, however, the divided text data “M” to be analyzed first is encoded into a start tag having “M” as a tag name. Then, in step S208, in order to store the state in the middle of the analysis, for example, in the case of FIG. 7, the pointer p so that the name in the partial schema points to the choice element below the define element of “moveType”. Update.

  On the other hand, in step S207, the reference destination node in the partial schema indicated by the pointer p is analyzed. Then, the divided text data is encoded as one text event based on the data type of the text data. When the partial schema shown in FIG. 7 is used, after the first divided text data “M” is encoded as the start tag, the divided text data “100” following “M” is a float defined in the partial schema. Encode as one text event with type.

  In step S208, the pointer p is updated so as to refer to the sibling node of the node currently pointed to by the pointer p. Therefore, after encoding the divided text data “100”, the pointer p refers to a <data type = “float”> node below the define element having “moveType” as a name. In this way, all divided text data constituting one text data is sequentially encoded.

  Returning to FIG. 5, next, in step S114, the end tag corresponding to the start tag encoded in step S112 is encoded. In the present embodiment, an end tag </ d> having a tag name “d” is encoded. On the other hand, in step S115, the same process as in step S113 is performed without outputting the start tag and the end tag encoded in steps S112 and S114.

  By performing the encoding process described above on the XML data in the text format shown in FIG. 1, the XML data in the binary format shown in FIG. 8B can be created. The binary shown in FIG. 8B is a binary corresponding to each unit.

  Data of the d attribute included in the path element of the XML data in the text format in FIG. 1 is converted so as to be included as a child element of the path element. The text data of the value of the d attribute is converted as a child element using a command such as “M” or “L” as a unit of a group (text data structural unit). In the element contents, coordinate information designated for the “M” and “L” commands is stored as each text event. When the application decodes the coordinate information specified for the “M” or “L” command, each coordinate information can be acquired as a separate text event.

  FIG. 9 shows the signs of the events related to the XML data in the binary format shown in FIG. Assume that the application knows the sign of each event in advance. FIG. 10 shows a name table referred to in FIG. This name table is a table that stores names of elements and attributes, codes assigned to the names, and data sizes of the names.

  FIG. 11A shows a value table referred to by the binary format XML data shown in FIG. This value table is a table storing element contents and attribute value values, codes assigned to the respective values, data types of the respective values, and data sizes of the respective values. The tables shown in FIGS. 10 and 11 (a) depend on the text-format XML data as the conversion source. Therefore, if the contents of the text-format XML data change, the tables shown in FIGS. The contents of the table change accordingly. FIG. 11B is a code table that is referred to as the data type of each value in the table shown in FIG. 11A, and is assumed to be known in advance by the application.

  Next, processing function blocks of the PC 101 will be described with reference to FIG. The structured document analysis unit 304 acquires and analyzes text-format XML data to be compressed and encoded into binary-format XML data.

  The schema selection unit 303 selects a partial schema describing a data type related to text data that is difficult to efficiently compress, and a definition name that is a root of information on the data type.

  The schema analysis unit 305 analyzes this partial schema and creates a DOM tree in the RAM 203. Further, the schema analysis unit 305 simplifies the document structure of the selected partial schema based on Chapter 4 simplification of the RELAX NG specification.

  The text data selection unit 302 acquires an XPath expression. The encoded document generation unit 306 selects text data corresponding to the defined partial schema by using the XPath expression. The encoded document generation unit 306 includes a text data analysis unit 307 and a text data encoding unit 309, and each unit operates as follows. The text data analysis unit 307 analyzes text data that matches the XPath expression, and the text data encoding unit 309 performs each encoding process described above.

Claims (8)

Means for obtaining a structured document in text format;
Means for analyzing the structured document and detecting text data;
An information processing apparatus comprising: generating means for converting the structured document by converting the text data into child elements, and generating a structured document in a binary format based on the converted structured document.   The information processing apparatus according to claim 1, wherein the text data is an attribute value included in the structured document.   The information processing apparatus according to claim 1, wherein the text data is element content included in the structured document. The generating means includes
Means for obtaining a schema defining the structure of the text data;
4. The information processing apparatus according to claim 1, further comprising: a conversion unit configured to convert the structured document by converting the text data into a child element using the schema. 5. The converting means includes
In the text data, for a variable corresponding to an enumerated value defined below the group element of the schema, means for converting the enumerated value into a start tag having a tag name;
5. The information processing apparatus according to claim 4, further comprising: means for setting a value subsequent to the variable in the text data to data subsequent to the start tag. 6. Obtaining a structured document in text format;
Analyzing the structured document and detecting text data;
An information processing method comprising: a step of converting the structured data by converting the text data into child elements, and generating a structured document in a binary format based on the converted structured document.   The computer program for functioning a computer as each means of any one of Claims 1 thru | or 5.   A computer-readable storage medium storing the computer program according to claim 7.

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