com.jeesuite.mybatis.datasource.MultiDataSourceManager Maven / Gradle / Ivy

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/**
 * 
 */
package com.jeesuite.mybatis.datasource;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicLong;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.jeesuite.common.TenantIdHolder;
import com.jeesuite.mybatis.MybatisConfigs;
import com.jeesuite.mybatis.MybatisRuntimeContext;
import com.jeesuite.mybatis.plugin.JeesuiteMybatisInterceptor;

/**
 * 多数据源管理器
 * @description 

 * @author vakin
 * @date 2016年2月2日
 * @Copyright (c) 2015, jwww
 */
public class MultiDataSourceManager {

	private static final Logger logger = LoggerFactory.getLogger(MultiDataSourceManager.class);
	
	private static final String NON_TENANT_KEY = "_none";
	private final static AtomicLong counter = new AtomicLong(10);
	private static final Map masters = new HashMap<>();
	private static final Map> slaves = new HashMap<>();
	
	private static volatile MultiDataSourceManager instance = new MultiDataSourceManager();

	private MultiDataSourceManager() {
	}

	public static MultiDataSourceManager get() {
		return instance;
	}

	protected void registerDataSourceKey(String dsKey) {
		
		String tenantId = dsKey.startsWith("tenant") ? dsKey.split("\\[|\\]")[1] : NON_TENANT_KEY;
		if (dsKey.contains("master")) {
			masters.put(tenantId, dsKey);
		} else {
			if(!slaves.containsKey(tenantId)){
				slaves.put(tenantId, new ArrayList<>());
			}
			slaves.get(tenantId).add(dsKey);
		}
		
		if(!NON_TENANT_KEY.equals(tenantId)){
			TenantIdHolder.addTenantId(tenantId);
		}
	}
	
	/**
	 * 获取当前数据源名
	 * 
	 * @return
	 */
	protected String getDataSourceKey() {
		String tenantId = MybatisRuntimeContext.getTenantId();
		if(tenantId == null || !MybatisConfigs.isTenantModeEnabled()){
			tenantId = NON_TENANT_KEY;
		}
		
		if(tenantId == null){
        	throw new DataSourceRouteException("Tenant routeKey Not found");
        }
		
		String dsKey = null;
		DataSourceContextVals vals = MybatisRuntimeContext.getDataSourceContextVals();
		if(JeesuiteMybatisInterceptor.isRwRouteEnabled() == false){
			dsKey = masters.get(tenantId);
		}else{
	        if (vals.forceMaster || !vals.userSlave){
				dsKey = masters.get(tenantId);
			}else{
				dsKey = selectSlave(tenantId);
			}
	        vals.dsKey = dsKey;
		}
		
        if(dsKey == null){
        	throw new DataSourceRouteException("Not found any dsKey for ["+tenantId+"]");
        }
        
        if(logger.isDebugEnabled() && !NON_TENANT_KEY.equals(tenantId)) {        	
        	logger.debug("current route rule is:tenantId:[{}],userSlave[{}]|forceMaster[{}], use dataSource key is [{}]!",tenantId,vals.userSlave,vals.forceMaster,vals.dsKey);
        }
		
		return dsKey;
	}

	/**
	 * 轮循分配slave节点
	 * 
	 * @return
	 */
	private static String selectSlave(String tenantId) {
		//  无从库则路由到主库
		if (slaves.isEmpty()) {
			if(logger.isDebugEnabled()) {				
				logger.debug("current no slave found ,default use [{}]!",masters.get(tenantId));
			}
			return masters.get(tenantId);
		}
		if (slaves.size() == 1)
			return slaves.get(tenantId).get(0);
		
		int selectIndex = (int) (counter.getAndIncrement() % slaves.size());
		String slaveKey = slaves.get(tenantId).get(selectIndex);
		return slaveKey;
	}
}