一级缓存数据结构

在这里插入图片描述

找到PerpetualCache,

一级缓存实质上是一个HashMap对象

缓存何时被创建的？

public CacheKey createCacheKey(MappedStatement ms, Object parameterObject, RowBounds rowBounds, BoundSql boundSql) {
           if (this.closed) {
               throw new ExecutorException("Executor was closed.");        } else {
               CacheKey cacheKey = new CacheKey();            cacheKey.update(ms.getId());            cacheKey.update(rowBounds.getOffset());            cacheKey.update(rowBounds.getLimit());            cacheKey.update(boundSql.getSql());            List
   
     parameterMappings = boundSql.getParameterMappings();            TypeHandlerRegistry typeHandlerRegistry = ms.getConfiguration().getTypeHandlerRegistry();            Iterator var8 = parameterMappings.iterator();            while(var8.hasNext()) {
                   ParameterMapping parameterMapping = (ParameterMapping)var8.next();                if (parameterMapping.getMode() != ParameterMode.OUT) {
                       String propertyName = parameterMapping.getProperty();                    Object value;                    if (boundSql.hasAdditionalParameter(propertyName)) {
                           value = boundSql.getAdditionalParameter(propertyName);                    } else if (parameterObject == null) {
                           value = null;                    } else if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
                           value = parameterObject;                    } else {
                           MetaObject metaObject = this.configuration.newMetaObject(parameterObject);                        value = metaObject.getValue(propertyName);                    }                    cacheKey.update(value);                }            }            if (this.configuration.getEnvironment() != null) {
                   cacheKey.update(this.configuration.getEnvironment().getId());            }            return cacheKey;        }    }

可以看到，在Executor中创建了cache,

key值中保存了，statementId+分页信息+sql语句+mybatis配置信息

value保存了doQuery查询出的保存结果