Implementation:Apache Shardingsphere YamlRuleNodeTupleSwapperEngine Swap

Knowledge Sources	Apache_Shardingsphere
Domains	Mode_Management, Configuration
Last Updated	2026-02-10 00:00 GMT

Overview

YamlRuleNodeTupleSwapperEngine is a bidirectional conversion engine between YAML rule configurations and RuleNodeTuple objects for registry persistence.

Description

YamlRuleNodeTupleSwapperEngine handles the conversion of YAML rule configurations to registry node tuples and vice versa. For forward conversion (config-to-tuples), it reflects on annotated fields, distinguishing between named items (Map/Collection with key generators) and unique items (scalar values, collections, enums). Named items produce one tuple per entry, while unique items produce a single tuple. For reverse conversion (tuples-to-config), it instantiates a new YamlRuleConfiguration and populates fields by matching tuple paths against DatabaseRuleNodePath patterns. The engine supports global rule configs as single leaf tuples and database-level configs as multi-tuple structures. It handles field types including String, boolean, int, long, Enum, Collection, Map, and complex YAML-serializable objects.

Usage

Use this engine when persisting rule configurations to the registry (converting config objects to path/value tuples) or when loading rule configurations from the registry (assembling tuples back into config objects). It is central to the configuration persistence pipeline.

Code Reference

Source Location

• Repository: Apache_Shardingsphere
• File: YamlRuleNodeTupleSwapperEngine.java
• Lines: 1-238

Signature

public final class YamlRuleNodeTupleSwapperEngine {

    public RuleNodeTuple swapToTuple(final YamlGlobalRuleConfiguration yamlGlobalRuleConfig)

    public Collection<RuleNodeTuple> swapToTuples(final String databaseName,
                                                   final YamlRuleConfiguration yamlRuleConfig)

    public YamlRuleConfiguration swapToYamlGlobalRuleConfiguration(
            final String ruleType, final String ruleContent)

    public YamlRuleConfiguration swapToYamlDatabaseRuleConfiguration(
            final String databaseName, final String ruleType, final Collection<RuleNodeTuple> tuples)
}

Import

import org.apache.shardingsphere.mode.node.rule.tuple.YamlRuleNodeTupleSwapperEngine;

I/O Contract

Inputs

Name	Type	Required	Description
yamlGlobalRuleConfig	YamlGlobalRuleConfiguration	Yes	Global rule configuration to convert to a single tuple
databaseName	String	Yes	Database name for database-level rule tuple paths
yamlRuleConfig	YamlRuleConfiguration	Yes	Database rule configuration to convert to tuples
ruleType	String	Yes	Rule type for reverse conversion lookups
ruleContent	String	Yes	YAML content for global rule deserialization
tuples	Collection<RuleNodeTuple>	Yes	Tuples to assemble back into a rule configuration

Outputs

Name	Type	Description
tuple	RuleNodeTuple	Single tuple for global rule configuration
tuples	Collection<RuleNodeTuple>	Collection of tuples for database rule configuration
yamlRuleConfig	YamlRuleConfiguration	Reassembled YAML rule configuration from tuples

Usage Examples

YamlRuleNodeTupleSwapperEngine engine = new YamlRuleNodeTupleSwapperEngine();

// Convert database rule config to tuples for persistence
Collection<RuleNodeTuple> tuples = engine.swapToTuples("my_db", yamlShardingConfig);

// Convert tuples back to YAML config during loading
YamlRuleConfiguration config = engine.swapToYamlDatabaseRuleConfiguration(
    "my_db", "sharding", tuples);

// Convert global rule config to a single tuple
RuleNodeTuple globalTuple = engine.swapToTuple(yamlAuthorityConfig);

Related Pages

• Principle:Apache_Shardingsphere_Configuration_Object_Conversion