62 results about "Xpath expression" patented technology

A method for using pre-computed information stored in auxiliary structures to speed up processing of expensive queries on hierarchical documents such as XML documents being queried using XPath. The invention defines a taxonomy of such structures such as indexes and materialized views for storing pre-computed XPath results (PXRs), determines what portion of the query can be evaluated by the structures, and computes the compensation for the results generated by the structures. The invention detects all structures applicable to the query and rewrites the query to use such structures, speeding up the performance of the queries. The invention identifies the matching structures by detecting containment mappings between XPath expressions in the query and the structure. The invention also includes a new representation for XPath expressions that is rich enough to express all features of XPath.

The disclosed teachings provide methods and systems for efficient evaluation of XPath queries. In particular, the disclosed evaluation methods require only polynomial time with respect to the total size of an input XPath query and an input XML document. Crucial for the new methods is the notion of “context-value tables”. This idea can be further refined for queries in Core XPath and XSLT Patterns so as to yield even a linear time evaluation method. Moreover, the disclosed methods can be used for improving existing methods and systems for processing XPath expressions so to guarantee polynomial worst-case complexity.

First data that represents a level associated with an element within an expression, such as an XPath expression, is generated from the expression, and stored in one or more columns of a table. Second data that represents a condition on an attribute of the element is generated from the expression, and stored in one or more columns of the same or a different table. A plurality of expressions can be processed as such, and a determination made whether any of the expressions match with a given hierarchical data item, such as an XML document, that includes a value that corresponds to an attribute that is associated with an element that resides at a particular level within the data item. Such determination is made based on whether the particular level matches the first data and the value satisfies the second data associated with a given expression.

A method of processing queries, e.g., XPath expressions, related to an XML document includes generating a plurality of tokens based on the contents of the XML document. At least one query expression is compiled to a first plurality of query nodes defining a tree. A plurality of lookup tables may be configured to relate each of the first plurality of query nodes by a symbol. Each token is processed by looking up the query nodes indexed by a symbol matching the token in one of the plurality of lookup tables, marking each of the related query nodes, and indicating a match if each of the first plurality of query nodes of the at least one query expression is marked. A system for performing the method includes a tokenizer, an expression compiler, and an engine module.

A method and system for evaluating a path query are disclosed. The path query corresponds to a query tree including a plurality of query nodes. At least one query node corresponds to at least one predicate and is at a level. The predicate(s) are evaluated for previous query node(s). The method and system include scanning data nodes of a document and determining if the data nodes match the query nodes. The method and system also include placing data related to the data node in match stacks corresponding to matched query nodes. The data for the query node(s) include attribute(s) corresponding to the predicate(s). The method and system further include propagating a matching of the at least one query node backward to a matching of the at least one previous query node.

An XPath generation system generates a default XPath expression (XPath) from a selected destination node. The system provides to a user the default XPath with modification options. The system modifies the default XPath according to selected modification options to generate a resulting XPath. If none of the modifications options are selected, the system selects the default XPath as the resulting XPath. The modification options comprise selecting a different node as a destination node of the XPath, selecting a context node as a starting node of the XPath, selecting an axis for specifying a path between the context node and the destination node, specifying selection of a node by name or by type, specifying selection of any node, and specifying return of only unique values of the resulting XPath.

A method and system for generating robust XPath expressions for a selected node in transcodable markup. The system of the invention can include a set of differing XPath expression generators; an interface through which at least one of the XPath expression generators can be selected; and, an XPath generator processor configured to apply each of the selected XPath expression generators to the selected node in the transcodable markup to produce a redundant set of robust XPath expressions configured to identify the selected node. Notably, the system also can include an XPath resolution processor. The XPath resolution processor can resolve each XPath expression in the redundant set. The resolutions, in turn, can identify a set of candidate nodes, the XPath resolution processor identifying the selected node from among the set of candidate nodes based upon the XPath expressions resolving to the selected node more than any other node in the set of candidate nodes.

An apparatus, system, and method are disclosed for optimization of XPath expressions in a database management system configured to accept XML queries. Operations of the method include receiving an XQuery representation and partitioning XPath expressions within the XQuery representation into a plurality of XPath expression clusters. The XPath expression clusters may comprise one or more XPath expressions and those in each cluster may operate on a common document. Furthermore, the XPath expressions in each cluster are hierarchically related to each other such that branch nodes of the cluster are executable independent of nodes in other XPath expression clusters. The method also defines merging the one or more XPath expressions into one or more expression trees for each XPath expression cluster. The method generates one or more query execution plans from the one or more XPath expression blocks. The method includes, for each query execution plan, splitting each of the XPath expression blocks into one or more ordered fragments. The method determines a cardinality according to database statistics and an execution cost for each XPath expression block within each query execution plan. Finally, the method determines an aggregate cardinality for each query execution plan and an aggregate execution cost for each query execution plan. Therefore, an XQuery may be optimized at both the global XQuery and local XPath expression block level, improving performance and reducing overhead.

A system and method for building an XQuery using a model-based XQuery building tool is presented. An XQuery builder includes a general user interface (GUI) that enables a user to graphically interpret XML source documents and create a query model. The XQuery builder then optimizes the query model by generating relative paths for nodes and converting FLWOR expressions to XPath expressions. In addition, the XQuery builder inserts runtime parameters into the query model that correspond to XML documents that are required to test the XQuery. Subsequently, the XQuery builder generates an XQuery from the optimized query model, and provides the XQuery and required XML documents to a query engine that, in turn, produces query results.

A method, computer readable medium and information processing system for projecting a representation of a document in the Extensible Markup Language (XML) format. The method dynamically creates a tree representation of an XML document based on a provided set of XPath expressions through approximate matching techniques. The projection created by the method supports all XPath axes including backward axes such as ?parent? and ?ancestor.? The execution of the set of XPath queries on the projected document is guaranteed to be the same as that of executing the XPath queries on the original document. The projected document typically occupies much less space than the original document.

The invention relates to an extensible intelligent contract vulnerability detection method, and belongs to the technical field of intelligent contracts. The method comprises the following steps: firstly, summarizing vulnerability characteristics of the intelligent contract according to common intelligent contract safety vulnerabilities, and constructing a intelligent contract vulnerability rule base according to a characteristic custom rule; when a user detects the intelligent contract source code, a lexical analyzer and a syntax analyzer are generated through a self-defined ANTLR syntax rule,lexical analysis and syntax analysis are conducted on the intelligent contract source code, and the intelligent contract source code is converted into an abstract syntax tree and then converted intoXML intermediate representation; then extracting an XPath expression in the rule base file to inquire and locate matched nodes in the XML intermediate representation; and finally, repositioning the row number in the source code to form a vulnerability analysis report. By constructing the custom contract vulnerability rule base, detection is convenient, the speed is high, the accuracy is high, andthe expansibility is good.

An XML wrapper queries an XML document in an on-the-fly manner so that only parent nodes in the document that satisfy the query are extracted and then unnested. The parent nodes and associated descendent nodes are located using XPath expressions contained as options in data definition language (DDL) statements. The parent nodes satisfying the query and associated descendent nodes are extracted and stored outside of a database according to a relational schema. The wrapper facilitates applications that use convention SQL queries and views to operate on that information stored according to the relational schema. The wrapper also responds to query optimizer requests for costs associated with queries against external data sources associated with the wrapper.

The invention discloses an access control system, belonging to the field of network communication. In the system, a policy implementation point transmits a decision request to a policy decision point, wherein requested resource information in the decision request is described by using a subtree filter expression; the policy decision point matches the requested resource information described by using the subtree filter expression with resource information described by adopting an extensible markup language path XPATH expression in an access control policy, makes a decision based on a matching result to allow or refuel the access to the requested resource information, and returns the decision to the policy implementation point; and the policy implementation point allows or refuses the access to the requested resource information based on the decision returned by the policy decision point. The invention solves the problem that the access control cannot be carried out on the access request of the requested resource described by using the subtree filter expression in the prior art, and the invention also discloses an access control method and device.

The invention discloses a semi-automatic vertical crawler generation tool and method. The semi-automatic vertical crawler generation method comprises the steps that a user can select to newly establish a template or adopt the lex-yacc technology to open a template, conduct lexical and grammatical analysis on a template file, maintain a symbol table and construct a grammatical analysis tree; a tree template structure is constructed according to the content of the template by searching for the rules of the lexical and grammatical analysis and storing and processing data in the whole analysis process; according to the content to be extracted, template nodes are increased, modified or deleted in the tree template structure, wherein node information contains the skip relation, an XPath expression and the data storage modes; the template is saved. The semi-automatic vertical crawler generation tool comprises an automatic crawler generation tool module and a crawler module. According to the semi-automatic vertical crawler generation tool and method, automatic generation of the template content replaces manual configuration of the template, so that the template is configured more conveniently and quickly, and the workload of related staff can be greatly saved.

Embodiments of the invention provide systems and methods for searching for elements of a document based on an order priority of attributes of a query expression. According to one embodiment, a method of searching a plurality of objects of a document, such as elements of a DOM document, can comprise generating a query expression with attributes related to a target object of the document. For example, the expression can comprise an XPath expression. The attributes of the query expression can be parsed into one or more attribute groups, each comprising at least one attribute, based on logical operators between the attributes. Each one or more attribute groups of each expression can be weighted and a search can be performed for the target object in the document based on the weighted one or more attribute groups of the query expression.

The invention discloses an extensible markup language (XML) data bank full-text indexing method based on integer mapping. The method comprises: a, full-text index of an XML document collection is established; and b, full-text retrieval is conducted through the established full-text index. The step a specifically comprises: information corresponding to data nodes in the XML document is calculated and stored; an XPath expression input by a user is analyzed and a corresponding node set is obtained; the lasting integer mapping is established and each node in the node set is mapped on an only integer; and the full-text index is conducted on node content. The step b specifically comprises: an XML full-text inquiring sentence input by the user is analyzed; key words are inquired in relationship list full-text index and a virtual column number integer is returned; and the virtual column number integer is inquired in a tree B and matched node structure information and full-text information are returned to the user. The index offered by the indexing method is small in occupied physical space, repeatedly stored path information does not exist and inquiring efficiency is improved.