Orchestration Rule Verification Method for CA-CCML Language Visualization Model

Abstract

The present invention provides a method for verifying the choreography rules of a CA-CCML language visualization model. Specifically, it includes: generating a unique node descriptor for each graphical node type of the CA-CCML language visualization model; using context-free grammar to describe the choreography rules of the CA-CCML language visualization model, and inputting the described choreography rules into an LALR(1) parser to generate a rule analysis table; based on the rule analysis table, verifying the choreography rules for each path of the actually generated visualization model, so as to obtain a verification result. The present invention applies the LALR(1) parser to the process of verifying the choreography rules of the CA-CCML language visualization model, eliminating the need for branch logic judgment, reducing redundant verification, and having strong maintainability.

Description

Technical Field

[0001] The present invention relates to the technical field of data verification, and more particularly, to a method for verifying the orchestration rules of a CA-CCML language visualization model. Background Art

[0002] With the development of Internet technology, a large number of Web services with single functions have emerged in the network. Web service composition combines Web services with single functions into composite services according to specific rules to achieve more complex functions. Currently, there have been a large number of related studies on Web service composition, and these studies have proposed various Web service composition languages, such as WS-CDL, BPEL, OWL-S, CA-CCML, etc. Some of these languages provide a visualization Web service composition environment, such as CA-CCML language, BPEL, etc.

[0003] CA-CCML (Context-aware Cooperative Composition Modeling Language) is a context-aware Web service composition modeling language. It uses XML format to describe Web service composition, and can not only describe the static information of Web services, but also describe the dynamic interactions between services. The visualization Web service composition environment of CA-CCML language contains various types of Web service composition graphic nodes. Through visualization, it orchestrates Web service composition to generate a visualization model, and can convert the visualization model into a text model. The visualization Web service composition environment of CA-CCML language simplifies the complex text editing process of Web service composition languages, making the Web service composition process more intuitive and efficient. However, the visualization Web service composition environment of CA-CCML language uses a method of making branch logic judgments on each graphic node according to the orchestration rules between nodes for verifying the orchestration rules, which results in a large number of redundant judgments during the program execution process, leading to low verification efficiency of the program. And when the composition rules change, a large modification to the program is required, so the maintainability of the program is poor.

[0004] Currently, in the visual Web service composition environment, there is relatively little research on validating the choreography rules of visual models. Most traditional Web service composition languages do not even have a visual Web service composition environment. The method for validating the choreography rules of the visual model provided by the CA-CCML language is to validate the choreography rules for the successor nodes of each graphical node in the visual model in the program. For example, assume there is a choreography rule that states that a graphical node of type A must be followed by a graphical node of type B. Then, when the validation program validates the choreography rule for the graphical node A, it obtains the successor node of node A and uses an if statement to determine whether the node is of type B. If the node following node A is of type B, it indicates that the choreography of A followed by B is acceptable; otherwise, it is an unacceptable choreography. However, this method has the following disadvantages:

[0005] (1) When there are many choreography rules, the program will generate a large number of branch logics. For example, in the above-mentioned assumption, if it is stipulated that the successor nodes of a graphical node of type A can be ten different types of nodes, then when validating the choreography rule for a node of type A, at least ten branch logics will be generated. And so on, the more choreography rules there are, the more branch logics there will be, and the more complex the program will be.

[0006] (2) A large number of redundant validations are likely to occur. Assume that the choreography rule stipulates that the successor node of a graphical node of type A is B. When faced with the choreography situation of ABAB, the validation program will perform the same validation twice for the two type A graphical nodes. That is, when validating the first A node, it will use the if statement in the program to determine whether the successor node is B. When validating the second A node, it will reuse the if statement to determine whether the successor node is B. Therefore, duplicate logical judgments will be made for the two type A nodes.

[0007] (3) The maintainability of the program is poor. When the choreography rules of the visual model change, the source code needs to be modified, and the logic of the program needs to be modified in the source code, making the program difficult to maintain. Summary of the Invention

[0008] Aiming at the problem that the current CA-CCML language uses a large number of branch structure programs to validate the choreography rules in the process of validating the choreography rules of the visual model, resulting in low validation efficiency and poor maintainability of the program, the present invention proposes a new method for validating the choreography rules of the CA-CCML language visual model. The context-free grammar is used to describe the choreography rules of the CA-CCML language visual model, and the choreography rules are input into the LALR(1) parser to generate a rule analysis table. Before the visual model is executed, the choreography rules of the model are validated according to the rule analysis table.

[0009] The technical means adopted by the present invention are as follows:

[0010] An orchestration rule verification method for a CA-CCML language visualization model, comprising the following steps:

[0011] Generate a unique node descriptor for each graphical node type of the CA-CCML language visualization model;

[0012] Describe the orchestration rules of the CA-CCML language visualization model using context-free grammar, and input the described orchestration rules into an LALR(1) parser to generate a rule analysis table;

[0013] Verify the orchestration rules for each path of the actually generated visualization model based on the rule analysis table to obtain a verification result.

[0014] Further, verifying the orchestration rules for each path of the actually generated visualization model based on the rule analysis table includes:

[0015] Use the visualization process orchestrator of the CA-CCML language to perform Web service composition process orchestration to generate a visualized Web service composition model;

[0016] Parse the Web service composition model through an orchestration rule verification program to generate a path table;

[0017] Verify the orchestration rules for each path in the path table. If the orchestration rules for all paths are acceptable, it means that the orchestration rule verification of the Web service composition model passes; otherwise, it fails.

[0018] Further, verifying the orchestration rules for each path in the path table includes:

[0019] a. Obtain a path path from the path table, and assign the start node in the path path to node;

[0020] b. Obtain the successor node nextNode of the node node;

[0021] c. Query the rule analysis table ruleTable, and obtain the action op corresponding to nextNode to determine whether it is empty. If it is empty, the verification fails; otherwise, execute step d;

[0022] d. Execute the action corresponding to op and update the node value to nextNode. Determine whether node is an end node. If it is, execute step e; if not, execute step b;

[0023] e. Determine whether all paths path have been traversed. If so, the verification passes; otherwise, execute step a.

[0024] Further, the graphical node types in the CA-CCML language visualization model include start nodes, branch nodes, parallel nodes, service nodes, unidirectional arrow nodes, context nodes, variable nodes, and end nodes.

[0025] Further, based on the rule analysis table, each path of the actually choreographed visualization model is checked for choreography rules, including defaulting the verification results of unidirectional arrow nodes, context nodes, and variable nodes as passed.

[0026] Further, context-free grammar is used to describe the choreography rules of the CA-CCML language visualization model, including:

[0027] Terminals are represented by lowercase descriptors;

[0028] Non-terminals are represented by uppercase descriptors;

[0029] Each choreography rule is described as a production, and a production includes a production head, the symbol "->", and a production body.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] 1. For the successor nodes of each graphical node of the present invention, the next action type can be quickly found in the rule analysis table without the need for branch logic judgment, and the verification efficiency is significantly improved.

[0032] 2. For the repeatedly occurring graphical nodes of the same type in the present invention, there is no need to perform repeated if-statement logic judgments on the graphical nodes of the same type, because the next action to be performed can be directly determined in the rule analysis table, reducing redundant judgments.

[0033] 3. When the choreography rules of the visualization model change, the method of the present invention only needs to regenerate a new rule analysis table and replace the old rule analysis table, without the need to modify the judgment logic of the program.

[0034] For the above reasons, the present invention can be widely promoted in the field of Web composite service model choreography verification. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1Flowchart of the method for verifying the choreography rules of the CA-CCML language visualization model in the embodiment.

[0037] Figure 2 State transition diagram in the embodiment.

[0038] Figure 3 Path verification process of the CA-CCML language visualization model in the embodiment. Detailed implementation manners

[0039] In order to enable those skilled in the art of the present technology to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0041] The present invention provides a method for verifying the choreography rules of a CA-CCML language visualization model, including the following steps:

[0042] S1. Generate a unique node descriptor for each graphical node type of the CA-CCML language visualization model.

[0043] S2. Describe the choreography rules of the CA-CCML language visualization model using context-free grammar, and input the described choreography rules into the LALR(1) parser to generate a rule analysis table.

[0044] S3. Based on the rule analysis table, verify the choreography rules for each path of the actually generated visualization model to obtain a verification result. Specifically, it includes:

[0045] S301. Use a visual process orchestrator in CA-CCML language to orchestrate the Web service composition process and generate a visual Web service composition model;

[0046] S302. Parse the Web service composition model through an orchestration rule verification program to generate a path table;

[0047] S303. Verify the orchestration rules for each path in the path table. If the orchestration rules for all paths are acceptable, it means that the orchestration rule verification of the Web service composition model passes; otherwise, it fails. Among them, verifying the orchestration rules for each path in the path table includes:

[0048] a. Obtain a path path from the path table, and assign the start node in the path path to node;

[0049] b. Obtain the successor node nextNode of the node node;

[0050] c. Query the rule analysis table ruleTable, and check whether the action op corresponding to nextNode is empty. If it is empty, the verification fails; otherwise, execute step d;

[0051] d. Execute the action corresponding to op and update the node value to nextNode. Check whether node is an end node. If it is, execute step e; if not, execute step b;

[0052] e. Check whether all paths path have been traversed. If so, the verification passes; otherwise, execute step a.

[0053] Next, through a specific application example, the solution and effect of the present invention will be further described.

[0054] As Figures 1 - 3 shown, the steps of a method for verifying the orchestration rules of a CA-CCML language visual model provided in this embodiment are as follows:

[0055] (1) Define the orchestration rules of the CA-CCML language visual model

[0056] The visual process orchestrator of the CA-CCML language provides a visual interface for users to intuitively orchestrate the CA-CCML visual model. The CA-CCML language visual model contains eight graphic nodes, and the corresponding node descriptors and visual icons are shown in Table 1.

[0057] Table 1 Node descriptors and visual icons corresponding to CA-CCML graphic nodes

[0058]

[0059] During the process choreography, it is necessary to determine whether the choreographed process complies with the choreography rules. The present invention uses context-free grammar to describe the choreography rules (i.e., the syntax rules of the CA-CCML language) of the CA-CCML language visualization model. There are 11 choreography rules in total, as shown in Table 2.

[0060] In the process of choreographing the visualization model of the CA-CCML language, the unidirectional arrow node belongs to the control flow and represents the order of appearance of nodes in the process; the context node and the variable node are used to provide the data required for service execution to the service node and can be regarded as auxiliary nodes of the service node. Therefore, the present invention does not need to consider the verification of these three types of nodes, namely unidirectional arrows, contexts, and variables. That is, when using these three types of nodes, it is default that the verification passes. Therefore, there are no descriptors for these three types of nodes in Table 2.

[0061] Table 2 Choreography Rules of the CA-CCML Language Visualization Model

[0062]

[0063] In the choreography rules of Table 2, it is agreed that:

[0064] 1) Lowercase descriptors represent terminals, which are the smallest indivisible units in the choreography rules. Each terminal represents a node descriptor corresponding to a graphical node type, such as arrow, start, end, etc. (refer to Table 1);

[0065] 2) Uppercase descriptors represent non-terminals, such as SQ, S, etc. They are strings composed of terminals and non-terminals. Each non-terminal represents a composite structure. Table 2 adds 5 non-terminals, namely E, I, SQ, S, and P. E represents an expression, I represents a branch structure, SQ represents a sequential structure, S represents a complete path, and P represents a parallel structure;

[0066] 3) Each choreography rule is a production. A production consists of a production head, the symbol "->", and a production body. The production head is also called the left part and is a non-terminal symbol. The production body is also called the right part and is a string composed of zero or more terminals and non-terminals, describing a certain construction method of the string corresponding to the production head. For example, for the choreography rule "S->start Eend", "S" is the production head and "startEend" is the production body, indicating that the non-terminal S is a string composed of the terminal start, the non-terminal E, and the terminal end in the order of start first, then E, and finally end.

[0067] There are 11 choreography rules in Table 2, and each choreography rule is marked with a fixed serial number, which cannot be changed. The 11 choreography rules are described in detail as follows:

[0068] 1) Compilation rule "E -> SQ I". The serial number of this compilation rule is 1, which describes that expression E is composed of SQ and I in the order in the rule.

[0069] 2) Compilation rule "E -> SQ". The serial number of this compilation rule is 2, which describes that expression E is composed of SQ.

[0070] 3) Compilation rule "I -> if SQ I". The serial number of this compilation rule is 3, which describes that the branch structure I is composed of if, SQ, and I in the order in the rule.

[0071] 4) Compilation rule "I -> if SQ". The serial number of this compilation rule is 4, which describes that the branch structure I is composed of if and SQ in the order in the rule.

[0072] 5) Compilation rule "I -> if". The serial number of this compilation rule is 5, which describes that the branch structure I is composed of if.

[0073] 6) Compilation rule "P -> parallel service parallel". The serial number of this compilation rule is 6, which describes that the parallel structure P is composed of two parallels and one service in the order in the rule.

[0074] 7) Compilation rule "S -> start E end". The serial number of this compilation rule is 7, which describes that a complete path S is composed of start, E, and end in the order in the rule.

[0075] 8) Compilation rule "SQ -> service". The serial number of this compilation rule is 8, which describes that the sequential structure SQ is composed of service.

[0076] 9) Compilation rule "SQ -> service SQ". The serial number of this compilation rule is 9, which describes that the sequential structure SQ is composed of service and SQ in the order in the rule.

[0077] 10) Compilation rule "SQ -> P". The serial number of this compilation rule is 10, which describes that the sequential structure SQ is composed of P.

[0078] 11) Compilation rule "SQ -> P SQ". The serial number of this compilation rule is 11, which describes that the sequential structure SQ is composed of P and SQ in the order in the rule.

[0079] (2) Use the LALR(1) parser to generate the compilation rule analysis table

[0080] Input the scheduling rules generated above into the LALR(1) parser to generate a scheduling rule analysis table, as shown in Table 3. In the table, "$end" is a terminal symbol additionally generated by the LALR(1) parser.

[0081] The LALR(1) parser is a general syntax analysis algorithm. This algorithm has an input and an output. The input is the syntax rules of a language (i.e., production rules), and the output is an LALR(1) rule analysis table. The LALR(1) rule analysis table defines a finite number of states and also specifies some actions, such as shift actions, reduction actions, etc. If a shift-reduce conflict occurs in the LALR(1) rule analysis table finally generated by the LALR(1) parser for a syntax rule, then this syntax rule does not conform to the LALR(1) standard, and the generated LALR(1) rule analysis table cannot be used. The LALR(1) parser is usually used in the syntax rule verification process of programming languages. All reasonable programming languages have some syntax rules that conform to the LALR(1) standard. Since the present invention applies the LALR(1) parser to the scheduling rule verification of the CA-CCML language visualization model, the syntax rules are therefore called scheduling rules, that is, the scheduling rules are input into the LALR(1) parser to generate a rule analysis table for the CA-CCML language visualization model. The scheduling rules in Table 2 conform to the LALR(1) standard, so they can be input into the LALR(1) parser to generate a scheduling rule analysis table, and this scheduling rule analysis table is shown in Table 3.

[0082] The first column in Table 3 represents the state number. There are a total of 17 states in this rule analysis table, with the initial state being state 0. The remaining columns are divided into two major parts: terminal symbols and non-terminal symbols. When a state encounters a specific terminal symbol or non-terminal symbol, a state transition action will occur, as Figure 2 shown.

[0083] Table 3 Scheduling Rule Analysis Table

[0084]

[0085] Figure 2There are a total of 17 states. A state consists of two parts: the state content and the state transition condition. The "$accept" in state 1 is an auxiliary descriptor generated by the LALR(1) parser during the parsing process. The production rule "$accept -> S" in state 1 is also generated by the LALR(1) parser. The purpose of this production rule is to inform the LALR(1) when to stop the syntax analysis and accept the choreography rule. The state content represents an item of a production rule. An item consists of a production rule plus a "." located at a certain position in the production rule. For example, for the choreography rule "S -> start E end", it has four items, namely "S ->.start E end", "S -> start.E end", "S -> start E.end", and "S -> start E end.". The item "S ->.start E end" indicates that the algorithm expects to see a string in the next input that can be derived from "start E end"; the item "S -> start.E end" indicates that the algorithm has just seen a string in the input that can be derived from "start", and the algorithm expects to see a string in the next input that can be derived from "E end"; the item "S -> start E.end" indicates that the algorithm has seen a string in the input that can be derived from "start E", and expects to see a string in the next input that can be derived from "end"; the item "S -> start E end." indicates that the algorithm has seen a string in the input that can be derived from "start E end", and at this time, this string can be reduced to "S". The state transition condition consists of the arrows emitted from the state and the descriptions on the arrows. For example, for state 3, the arrow emitted from state 3 and the "end" above the arrow indicate that when state 3 encounters the terminal symbol "end", the state will transfer to state 8.

[0086] The content of each cell in the terminal symbol column in Table 3 represents a type of action. There are a total of 4 types, as shown in Table 4.

[0087] Table 4 Terminal Symbol Action Type Table

[0088]

[0089] The content of each cell in the non-terminal symbol column in Table 3 represents a state transition action. There are a total of 2 types of state transition action types, as shown in Table 5.

[0090] Table 5 Non-Terminal Symbol Action Type Table

[0091]

[0092] (3) Visualization Model of Choreography CA-CCML Language

[0093] Use a visual process orchestrator in CA-CCML language to orchestrate the Web service composition process and generate a visual Web service composition model. The visual process orchestrator in CA-CCML language provides a visual interface to facilitate users to intuitively orchestrate the CA-CCML visual model. The orchestrator provides corresponding visual icons for the eight graphic nodes of the CA-CCML language, as shown in Table 1, enabling users to edit the CA-CCML model in a graphical way.

[0094] (4) Parse the visual model of the CA-CCML language to generate a path table

[0095] Before the visual model of the CA-CCML language is executed, it needs to be submitted to an orchestration rule verification program for verification. After obtaining the visual model of the CA-CCML language, the orchestration rule verification program parses the visual model and stores each path in the visual model into the path table.

[0096] (5) Perform orchestration rule verification on each path in the path table

[0097] The orchestration rule verification program analyzes each path from the start node to the end node in the path table according to the rules in Table 3. If the orchestration rules of all paths are acceptable, it means that the orchestration rules of the visual model are acceptable, i.e., the verification passes; otherwise, it is not acceptable. The path verification process of the CA-CCML language visual model is as Figure 3 shown.

[0098] The path verification pseudocode of the CA-CCML language visual model can be seen in Algorithm 1.

[0099] The Web service composition language CA-CCML provides a visual Web service composition environment. By visually orchestrating the Web service composition, a corresponding visual model is generated, and then the environment executes the visual model. Before the visual model is executed, it is necessary to verify the orchestration rules of each path in the model. The present invention uses related technologies in compilation principles and applies the LALR(1) parser to the process of verifying the orchestration rules of the CA-CCML language visual model. The beneficial effects of the method of the present invention will be illustrated below by comparing the method of verifying the orchestration rules of the CA-CCML language visual model proposed by the present invention with the existing method of verifying the orchestration rules of the CA-CCML language visual model.

[0100]

[0101] The method for verifying the choreography rules of the CA-CCML language visualization model proposed by the present invention is more efficient than the existing method for verifying the choreography rules of the CA-CCML language visualization model (hereinafter simply referred to as the existing verification method). The existing verification method uses branch logic in the program to make judgments according to the choreography rules specified by the visualization model, which will affect the verification efficiency of the model. Suppose there is a graphic node of type A, and the successor nodes of the graphic node of type A can be graphic nodes of type B, C, or D. Suppose there is a choreography requirement of AD. When the existing verification method encounters node A, it looks ahead one node D and judges whether D is B, and the result returns false; then it judges whether D is C, and the result returns false; finally, it judges whether D is D, and the result returns true, then it executes the program corresponding to the successor node being D. The present invention proposes to use the LALR(1) parser to pre-generate a rule analysis table to perform choreography rule verification. When encountering node A, it looks ahead one node D and can obtain the action type when A encounters D by looking up the rule analysis table. This method has fewer judgment times and higher verification efficiency compared with the existing verification method.

[0102] In addition, the method for verifying the choreography rules of the CA-CCML language visualization model proposed by the present invention has higher program maintainability than the existing verification method. For the situation where the choreography rules change, the existing verification method needs to modify the source program deep inside the program for the change of the choreography rules. This way of program maintenance is not only cumbersome but also prone to various exceptions; while the method proposed by the present invention only needs to input the modified choreography rules into the LALR(1) parser to generate a new rule analysis table, without modifying the source program, so it has good program maintainability.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for validating the orchestration rules of a CA-CCML language visualization model, characterized in that, It includes the following steps: Generate a unique node descriptor for each graphical node type of the CA-CCML language visualization model; Describe the choreography rules of the CA-CCML language visualization model using context-free grammar, and input the described choreography rules into the LALR(1) parser to generate a rule analysis table; Based on the rule analysis table, perform choreography rule verification on each path of the actually generated visualization model to obtain a verification result, including: use the visualization process choreographer of the CA-CCML language to perform Web service composition process choreography to generate a visual Web service composition model, parse the Web service composition model through a choreography rule verification program to generate a path table, perform choreography rule verification on each path in the path table, if the choreography rules of all paths are acceptable, it means that the choreography rule verification of the Web service composition model passes, otherwise it fails; perform choreography rule verification on each path in the path table, including: a. Obtain a path path from the path table, and assign the start node in the path path to node; b. Obtain the successor node nextNode of the node node; c. Query the rule analysis table ruleTable, and obtain whether the action op corresponding to nextNode is empty. If it is empty, the verification fails, otherwise execute step d; d. Execute the action corresponding to op and update the node value to nextNode. Determine whether node is an end node. If it is, execute step e. If not, execute step b; e. Determine whether all paths path have been traversed. If so, the verification passes. Otherwise, execute step a.

2. The method for validating the orchestration rules of a CA-CCML language visualization model according to claim 1, characterized in that, The graphical node types in the CA-CCML language visualization model include start node, branch node, parallel node, service node, unidirectional arrow node, context node, variable node, and end node.

3. The method for validating the orchestration rules of a CA-CCML language visualization model according to claim 2, characterized in that, Based on the rule analysis table, perform choreography rule verification on each path of the actually choreographed visualization model, including defaulting the verification results of unidirectional arrow nodes, context nodes, and variable nodes to pass.

4. The method for validating the orchestration rules of a CA-CCML language visualization model according to claim 1, characterized in that, Describe the choreography rules of the CA-CCML language visualization model using context-free grammar, including: Represent terminal symbols by lowercase descriptors; Represent non-terminal symbols by uppercase descriptors; Describe each choreography rule as a production, and a production includes a production head, the symbol "->", and a production body.

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