基于小程序文件系统制作的本地数据库，目前已

大家好哇，我是梦辛工作室的灵，在最近的开发过程中又遇到了一些问题，这次是关于本地存储的，在小程序面进行存储一些数据，本来就依靠小程序的本地储存API 就可以实现，但数据量小还好，如果数据量大那么就不在方便了，主要就没办法查询或批量修改，我这次主要是因为小程序有无网络状态下也需要可以正常运行，所以我想着能不能直接把数据库放在本地算了，就样子就算没有网络也可以正常运行，然后有网络的时候再去做同步就可以，本着这样的想法，我就瞄上了小程序的文件储存API，如果我把我所需要的数据存在JSON里面然后再存在本地文件夹就可以了，然后就按照自己的想法写出来了MxLocalBase，目前已简单实现的数据库的建立、数据表的建立、事务、索引等，由于JS是单线程运行的，所以也就不用担心多线程的问题，下面来看下整体结构： 核心类就是bin下面的3个文件，util 文件夹里面主要是 用来做文件储存的辅助类， 先简单说明下如何使用吧 这3个类可以自己独立运行，Connect 可以用于管理 DataBase ，DataBase可以用于管理多个Table类 Table类用于管理文件数据 先说Connect的使用方法：

let curConn = new Connect(wx.getFileSystemManager(), basePath + path); let databaseList = curConn.showDataBases(); //获取数据库列表 curConn.useDataBase(baseName); //选择目前操作的数据库 let tableList = curConn.showTableList(); //获取当前数据库的数据表列表 let curDataBase = curConn.getCurDataBase();//获取当前操作的数据库对象 即使 DataBase 类 curConn.createTable(tableName,options) //创建数据表 //options 为数据表结构，其格式为：[item ,....] //item :{"name":"列名称"：, "type":"列类型 目前支持 string, number,object,boolean" , // "default"："默认值", "increment":"是否自动增加", "notNull":"是否不为null", //"primaryKey":"是否为主键", "uni":"是否为唯一键", "comment":"说明"} curConn.doAddTableSet(tableName,itemSet);// 数据表添加列 itemSet 和上述 item 一个格式 curConn.deleteDataBase(databaseName); //删除数据库 curConn.createDataBase(databaseName,error); //创建数据库 let table = tryConnectTable(tableName); //获取当前数据表对象 即 Table 类 curConn.deleteTable(tableName); // 删除数据表

DataBase 的使用方法：

let curDataBase = curConn.getCurDataBase(); //可以这样获取DataBase对象，也可以直接创建 let curDataBase = new DataBase(wx.getFileSystemManager(),databaseName,BasePath); curDataBase.createTable(tableName,options); // 创建数据表 同上 let curTable = curDataBase.tryConnectTable(tableName); //获取数据表 也同上 DataBase 创建的时候会读取本地的文件夹列表，视为数据表，并创建其数据表对象

Table的使用方法：

let curTable = curDataBase.tryConnectTable(tableName); //获取数据表 也可以直接创建 let curtable = new Table(wx.getFileSystemManager(), tableName, BasePath); curtable.setAutoCommit(false); // 开启事务 curtable.addTableSet(itemSet); // 添加列，属性同 上item curtable.modiftyTableSet(name,itemSet); // 修改列，name 列名称 itemSet属性同 上item curtable.deleteTableSet(name); //删除列 name 为列名称 curtable.modifyData(updateData, whereData); //修改数据 updateData 格式为 [{name:"列名",value:"值"}] // whereData 的格式为： [{name:"列名",type:"比对类型",value:"值"}] //目前比对在 util里面的 compareMap，并有其对应的判断方法 curtable.modifyDataByPathIndex(updateData, pathIndex, dataIndex) //修改数据 updateData 格式为 [{name:"列名",value:"值"}] //pathIndex 为数据所保存的文件索引，文件目前会按1000条数据划分文件，如 data_0.json pathIndex 就为0 //dataIndex 为数据所在文件的json中的行数，每个数据返回是都会有 pathIndex, dataIndex curtable.deleteDataByPathIndex({pathIndex, dataIndex}) //删除指定数据 curtable.deleteData(whereData) //删除数据，同上 curtable.selectData(whereData, mapFun, limitData, orderByData) //查询数据 whereData 格式同上 mapFun为自定义方法 //，每查询到合适的数据就会主动调用该方法 //limitData 为 {start：开始行数，count：返回条数} //orderByData 为排序对象 格式为：[{name:'列名',type:'排序规则，desc 或 asc'},....] curtable.addData(itemData);//添加的数据，格式为当前数据表结构 curtable.commit();//提交数据，若不开始事务，修改数据后，500ms 后就会自动保存到文件里

好了，然后在和大家讲下原理把，其实核心还是Table 类，其他的都只是用于管理罢了， Table 类里面的核心结构为

//数据列表 dataJsonList:[ { path: 'data_0.json', // 文件名称 pathIndex: index, //文件索引 data: [], //具体数据 read: 0, //读了几次，用于清理内存时，按读取次数清理，越小越容易被清理 modify: 0, //修改位，用于保存时判断是否需要重新写入文件 primaryKeyIndex:{}, //主键索引映射 uniIndex:{}, //唯一键索引映射 indexMap:{} //其他索引映射 } ] //数据表结构 setJson:[ { "data": [{ "name": "username", "default": "", "type": "string", "uni": true }, { "name": "password", "default": "", "type": "string", "uni": false }, { "name": "showname", "type": "string", "default": "", "uni": false }], "index": { "username": 0, "password": 1, "showname": 2 } } ]

目前我这边还写了一个微信小程序的展示界面： 代码已上传至github ，有兴趣的同学可以去看下，有什么问题还请大佬们多多指教 github传送门 gitee传送门

还是依旧老规矩，上源码： Connect.js

import FileManager from "../util/FileManager"; import DataBase from "./DataBase"; class Connect { constructor(manager,BasePath){ this.fileManmger = new FileManager(manager); this.BasePath = BasePath; try{ this.fileManmger.accessSync(BasePath); } catch (e){ this.fileManmger.mkdirSync({dirPath:BasePath,recursive:true}); } this.connect = 1; } checkFileExsites(filePath){ try{ this.fileManmger.accessSync(filePath); } catch (e){ return false; } return true; } isConnect(){ return this.connect == 1; } isSelectDataBase(){ if(this.databaseName){ if(!this.database || this.database.databaseName != this.databaseName){ this.database = new DataBase(this.fileManmger,this.databaseName,this.BasePath); } } return typeof this.databaseName == "string"; } useDataBase(databaseName,create){ if(!this.isConnect()){ throw("当前数据库未连接"); } let databasePath = this.BasePath + "/" + databaseName; if(!this.checkFileExsites(databasePath)){ if(create){ this.fileManmger.mkdirSync({dirPath:databasePath, recursive:true}); } else { throw("数据库:" + databaseName + " 不存在"); } } this.databaseName = databaseName; } createDataBase(databaseName,error){ if(!this.isConnect()){ throw("当前数据库未连接"); } let databasePath = this.BasePath + "/" + databaseName; if(!this.checkFileExsites(databasePath)){ this.fileManmger.mkdirSync({dirPath:databasePath, recursive:true}); this.databaseName = databaseName; } else { if(error)throw("数据库：" + databaseName + " 已存在，请勿重复创建"); } } deleteDataBase(databaseName){ if(!this.isConnect()){ throw("当前数据库未连接"); } let databasePath = this.BasePath + "/" + databaseName; if(!this.checkFileExsites(databasePath)){ throw("数据库:" + databaseName + " 不存在"); } this.fileManmger.rmdirSync({dirPath:databasePath,recursive:true}); if(this.databaseName == databaseName){ this.databaseName = ""; this.database = ""; } } tryConnectTable(tableName){ if(!this.isConnect()){ throw("当前数据库未连接"); } if(!this.isSelectDataBase()){ throw("当前未选择数据库"); } return this.database.tryConnectTable(tableName); } showDataBases(){ if(!this.isConnect()){ throw("当前数据库未连接"); } return this.fileManmger.readdirSync({dirPath:this.BasePath}); } showTableList(){ if(!this.isConnect()){ throw("当前数据库未连接"); } if(!this.isSelectDataBase()){ throw("当前未选择数据库"); } return this.database.showTables(); } doAddTableSet(tableName,itemSet){ if(!this.isConnect()){ throw("当前数据库未连接"); } if(!this.isSelectDataBase()){ throw("当前未选择数据库"); } return this.database.doAddTableSet(tableName,itemSet); } getCurDataBase(){ if(!this.isConnect()){ throw("当前数据库未连接"); } if(!this.isSelectDataBase()){ throw("当前未选择数据库"); } return this.database; } createTable(tableName,options){ if(!this.isConnect()){ throw("当前数据库未连接"); } if(!this.isSelectDataBase()){ throw("当前未选择数据库"); } this.database.createTable(tableName,options); } deleteTable(tableName){ if(!this.isConnect()){ throw("当前数据库未连接"); } if(!this.isSelectDataBase()){ throw("当前未选择数据库"); } this.database.deleteTable(tableName); } doShowTableSet(tableName){ if(!this.isConnect()){ throw("当前数据库未连接"); } if(!this.isSelectDataBase()){ throw("当前未选择数据库"); } return this.database.doShowTableSet(tableName); } closeConnect(){ this.connect = 0; } } export default Connect;

DataBase.js

import { log } from "../util/util"; import Table from "./Table"; class DataBase { tableMap = {} tableList = [] constructor(manager,databaseName,BasePath){ this.fileManmgerObject = manager; this.databaseName = databaseName; this.BasePath = BasePath; this.loadTableList(); } get CurPath(){ return this.BasePath + "/" + this.databaseName; } get CurTablePath(){ return this.BasePath + "/" + this.databaseName + "/" + this.tableName; } createTable(tableName,options){ let tablePath = this.CurPath + "/" + tableName; if(this.tableMap[tableName]){ throw("已存在数据表：" + tableName + " 请勿重复创建") } try{ this.fileManmger.mkdirSync({dirPath:tablePath, recursive:true}); this.fileManmger.mkdirSync({dirPath:tablePath + "/set", recursive:true}); this.fileManmger.mkdirSync({dirPath:tablePath + "/data", recursive:true}); this.fileManmger.mkdirSync({dirPath:tablePath + "/index", recursive:true}); if(options){ this.setTableOptions(tableName,options); } this.tableMap[tableName] = new Table(this.fileManmger,tableName,this.CurPath); } catch (e){ console.log(e) } } loadTableList(){ let tableList = []; try{ tableList = this.fileManmger.readdirSync({dirPath:this.CurPath}); } catch(e) { log(e); } for(let tableName of tableList){ this.tableMap[tableName] = new Table(this.fileManmger,tableName,this.CurPath); } this.tableList = tableList; } setTableOptions(tableName,options){ this.tryConnectTable(tableName); this.tableMap[tableName].setTableOptions(options); } tryConnectTable(tableName){ if(!this.tableMap[tableName]){ throw("不存在数据表：" + tableName) } if(!this.tableMap[tableName].isConnect){ this.tableMap[tableName] = new Table(this.fileManmger,tableName,this.CurPath); } return this.tableMap[tableName]; } get fileManmger(){ return this.fileManmgerObject; } doAddTableSet(tableName,itemSet){ this.tryConnectTable(tableName); return this.tableMap[tableName].addTableSet(itemSet); } showTables(){ return this.tableList; } deleteTable(tableName){ let tablePath = this.CurPath + "/" + tableName; if(!this.tableMap[tableName]){ throw("数据表:" + tableName + " 不存在"); } this.fileManmger.rmdirSync({dirPath:tablePath,recursive:true}); this.tableMap[tableName] = {}; delete this.tableMap[tableName]; this.tableList.splice(this.tableList.indexOf(tableName),1); } doShowTableSet(tableName){ this.tryConnectTable(tableName); return this.tableMap[tableName].setJson.data; } } export default DataBase;

Table.js

import FileManager from "../util/FileManager"; import util from "../util/util" let typeMap = { "string": 1, "number": 1, "boolean": 1, "object": 1 } let saveSetTimeout = 0; let saveDataJsonTimeout = 0; let releaseDataJsonTimeout = 0; let saveIndexJsonTimeout = 0; let MaxSaveLines = 1000; //一个文件最大保存1000条数据 let releaseLimitTime = 30 * 1000; // 读取数据 或 保存数据后多少秒清理内存 let releaseSaveCount = 3; // 释放内存数据时 保存数量 按readCount排序来释放 let saveLimitTime = 500;// 每隔500ms 才保存一次 class Table { constructor(manager, tableName, BasePath) { if (manager instanceof FileManager) { this.fileManmgerObject = manager; } else { this.fileManmgerObject = new FileManager(manager); } this.tableName = tableName; this.BasePath = BasePath; this.autoCommit = true; this.connect(); } setAutoCommit(autoCommit) { this.autoCommit = autoCommit; } connect() { if (this.isConnect) { return true; } try { this.fileManmger.accessSync(this.CurPath); } catch (e) { throw ("当前数据表不存在"); } this.isConnect = 1; this.loadTableSet(); this.loadTableDataPath(); this.loadTableIndex(); return true; } close() { this.checkConnect(); if (this.autoCommit) { this.commit(); } else { this.rollback(); } this.connect = 1; } get fileManmger() { return this.fileManmgerObject; } get CurPath() { return this.BasePath + "/" + this.tableName; } loadTableSet() { this.checkConnect(); this.setJson = this.readFileSync("/set/set.json", { data: [], index: {} }) } setTableOptions(options) { this.checkConnect(); if (this.setJson.data.length > 0) { throw ("当前数据表已存在结构，请勿重复设置"); } let setJson = { data: [], index: {} }; if (!options.column || typeof options.column[0] != "object") { throw ("错误的列表设置"); } let hasPrimaryKey = false; for (let item of options.column) { if (!item.name) { throw ("列表必须含有name字段"); } if (item.autoIncrement && item.type != "number") { throw ("自动增加类型只能为数字"); } if (item.primaryKey) { if (hasPrimaryKey) { throw ("主键仅能有一个字段"); } hasPrimaryKey = true; } setJson.data.push({ name: item.name, defaultValue: item.defaultValue || undefined, autoIncrement: item.autoIncrement || false, comment: item.comment || "无", type: item.type || "any", notNull: item.notNull, primaryKey: item.primaryKey || false, uni: item.uni }) setJson.index[item.name] = setJson.data.length - 1; } this.setJson = setJson; this.saveSetJson(); } readFileSync(path, defaultValue) { let result = defaultValue; try { let dataPath = this.CurPath + path; this.fileManmger.accessSync(dataPath); let readData = this.fileManmger.readFileSync({ filePath: dataPath, encoding: "utf-8", }) result = JSON.parse(readData) } catch (e) { util.log(e); } return result; } loadTableDataPath() { this.checkConnect(); try { let dataJsonPath = this.CurPath + "/data"; let resultData = this.fileManmger.readdirSync({ dirPath: dataJsonPath }); if (!(resultData instanceof Array)) { resultData = []; } let result = []; for (let index = 0; index < resultData.length; index++) { result.push({ path: 'data_' + index + '.json', pathIndex: index, data: [], read: 0, modify: 0, }) } this.dataJsonList = result; } catch (e) { util.log(e); this.dataJsonList = []; } } /** * * @param { * name:"字段名称", * type:"字段类型", * primaryKey:"是否为主键", * default:"默认值", * uni:"是否为唯一键" * } itemSet 字段属性 */ addTableSet(itemSet) { this.checkConnect(); this.checkItemSet(itemSet); let setJson = this.setJson; if (typeof setJson.index[itemSet.name] == "number") { throw ("当前字段已存在，请勿重复创建"); } if (itemSet.uni && typeof itemSet.default != "undefined") { throw ("唯一键默认值仅能为undefined"); } for (let item of setJson.data) { if (itemSet.primaryKey && item.primaryKey) { throw ("已存在主键"); } } let dataJsonList = this.dataJsonList; for (let dataJson of dataJsonList) { this.loadDataJson(dataJson); let index = 0; for (let item of dataJson.data) { if (typeof itemSet.default == "undefined") { item[itemSet.name] = undefined; } else { item[itemSet.name] = itemSet.default; if (dataJson.indexMap[itemSet.name]) { if (!dataJson.indexMap[itemSet.name][itemSet.default]) { dataJson.indexMap[itemSet.name][itemSet.default] = [index]; } else { dataJson.indexMap[itemSet.name][itemSet.default].push(index); } } } index++; } dataJson.modify = 1; } setJson.data.push(itemSet); setJson.index[itemSet.name] = setJson.data.length - 1; this.saveSetJson(setJson); this.commit(); } modiftyTableSet(name, itemSet) { this.checkConnect(); this.checkItemSet(itemSet); let setJson = this.setJson; if (typeof setJson.index[name] != "number") { throw ("修改字段不存在"); } if (typeof setJson.index[itemSet.name] != "number") { throw ("目标字段已存在，请勿重复创建"); } if (itemSet.uni && typeof itemSet.default != "undefined") { throw ("唯一键默认值仅能为undefined"); } if (itemSet.primaryKey && typeof setJson.index.primaryKey) { throw ("当前表已存在主键"); } let isIndex = false; if (this.indexJsonMap[srcSetJson.name]) { isIndex = true; } let dataJsonList = this.dataJsonList; for (let dataJson of dataJsonList) { this.loadDataJson(dataJson); let indexMap = {}; let index = 0; for (let item of dataJson.data) { let tempValue = item[name]; if (typeof tempValue == "undefined") { item[itemSet.name] = itemSet.default; } else { item[itemSet.name] = tempValue; indexMap[tempValue] = index; if (dataJson.indexMap[itemSet.name]) { if (!dataJson.indexMap[itemSet.name][tempValue]) { dataJson.indexMap[itemSet.name][tempValue] = [index]; } else { dataJson.indexMap[itemSet.name][tempValue].push(index); } } } if (isIndex) { delete dataJson.indexMap[itemSet.name]; } delete item[name]; index++; } if (itemSet.primaryKey) { dataJson.primaryKey = indexMap; } else if (itemSet.uni) { dataJson.uniIndex[itemSet.name] = indexMap; delete dataJson.uniIndex[name]; } if (srcSetJson.uni) { delete dataJson.uniIndex[name]; } else if (srcSetJson.primaryKey) { dataJson.primaryKey = {}; } dataJson.modify = 1; } setJson.data.splice(setJson.index[name], 1); setJson.data.push(itemSet); this.reIndexSetJson(setJson); this.saveSetJson(setJson); this.commit(); } deleteTableSet(name) { this.checkConnect(); let setJson = this.setJson; if (typeof setJson.index[name] != "number") { throw ("删除字段不存在"); } let srcSetJson = setJson.data[setJson.index[name]]; let dataJsonList = this.dataJsonList; let isIndex = false; if (this.indexJsonMap[srcSetJson.name]) { isIndex = true; } for (let dataJson of dataJsonList) { this.loadDataJson(dataJson); for (let item of dataJson.data) { delete item[name]; } if (srcSetJson.uni) { delete dataJson.uniIndex[name]; } if (srcSetJson.primaryKey) { dataJson.primaryKeyIndex = {}; } if (isIndex) { delete dataJson.indexMap[itemSet.name]; } dataJson.modify = 1; } setJson.data.splice(setJson.index[name], 1); this.reIndexSetJson(setJson); this.saveSetJson(setJson); this.commit(); } checkConnect() { if (!this.isConnect) { throw ("未连接当前数据表") } } checkItemSet(itemSet) { if (!itemSet.name) { throw ("列表必须含有name字段"); } if (!itemSet.type) { throw ("列表必须设置type字段"); } if (!typeMap[itemSet.type]) { throw ("type只能为：string、number、boolean、object"); } if (itemSet.autoIncrement && itemSet.type != "number") { throw ("自动增加类型只能为数字"); } } saveSetJson() { if (saveSetTimeout) { clearTimeout(saveSetTimeout); } saveSetTimeout = setTimeout(() => { this.fileManmger.writeFileSync({ filePath: this.CurPath + "/set/set.json", data: JSON.stringify(this.setJson), encoding: "utf-8" }) util.log("保存setJson") util.log(this.setJson) }, saveLimitTime) } saveDataJson(dataJson) { this.fileManmger.writeFileSync({ filePath: this.CurPath + "/data/" + dataJson.path, data: JSON.stringify(dataJson), encoding: "utf-8" }) util.log("保存dataJson") util.log(dataJson) } doSaveDataJson() { if (saveDataJsonTimeout) { clearTimeout(saveDataJsonTimeout); } saveDataJsonTimeout = setTimeout(() => { let dataJsonList = this.dataJsonList; for (let dataJson of dataJsonList) { if (dataJson.modify && dataJson.read) { this.saveDataJson({ data: dataJson.data, path: dataJson.path, primaryKeyIndex: dataJson.primaryKeyIndex, uniIndex: dataJson.uniIndex, indexMap: dataJson.indexMap || {} }); dataJson.modify = 0; } } this.releaseDataJson(); }, saveLimitTime) } /** * 读取数据文件 * @param {*} path */ readDataJson(path) { let result = this.readFileSync('/data/' + path, { data: [], primaryKeyIndex: {}, uniIndex: {}, indexMap: {} }); this.releaseDataJson(); return result; } /** * 重置表结构索引 * @param {*} setJson */ reIndexSetJson(setJson) { let indexMap = {}; let index = 0; for (let item of setJson.data) { indexMap[item.name] = index; index++; } setJson.index = indexMap; } /** * 修改数据 * @param {*} updateData {name:"列名",value:"值"} * @param {*} whereData {name:"列名",type:"比对类型",value:"值"} */ modifyData(updateData, whereData) { if (!updateData || !(updateData instanceof Array)) { throw ("更新数据格式不正确"); } let primaryKeyValue = undefined; let uniList = []; for (let updateJson of updateData) { let itemIndex = this.setJson.index[updateJson.name]; if (typeof itemIndex != "number") { throw ("未知列 " + updateJson.name); } let item = this.setJson.data[itemIndex]; if (item.primaryKey) { if (!updateJson.value) { throw ("主键 " + item.name + " 不能为空") } else { primaryKeyValue = updateJson.value; } } if (item.uni) { if (typeof updateJson.value == "undefined") { throw ("唯一键 " + item.name + " 不能为空") } else { uniList.push({ name: item.name, value: updateJson.value }); } } if (updateJson.value && typeof updateJson.value != item.type) { throw ("字段 " + item.name + " 类型不匹配 " + item.type) } } this.checkSaveValue(primaryKeyValue, uniList); let modifyCount = 0; this.selectData(whereData, (dataJson, curIndex, targetValue) => { for (let updateJson of updateData) { let itemIndex = this.setJson.index[updateJson.name]; let setItem = this.setJson.data[itemIndex]; if (setItem.primaryKey) { delete dataJson.primaryKeyIndex[targetValue[setItem.name]]; dataJson.primaryKeyIndex[updateJson.value] = curIndex; } else if (setItem.uni) { delete dataJson.uniIndex[setItem.name][targetValue[setItem.name]]; dataJson.uniIndex[setItem.name][updateJson.value] = curIndex; } if (this.indexJsonMap[setItem.name]) { delete dataJson.indexMap[setItem.name][targetValue[setItem.name]]; if (dataJson.indexMap[setItem.name][updateJson.value] instanceof Array) { dataJson.indexMap[setItem.name][updateJson.value].push(curIndex); } else { dataJson.indexMap[setItem.name][updateJson.value] = [curIndex]; } } targetValue[updateJson.name] = updateJson.value; } dataJson.modify = 1; modifyCount++; }) if (modifyCount > 0) { if (this.autoCommit) { this.commit(); } } return modifyCount; } /** * 修改数据 * @param {*} updateData {name:"列名",value:"值"} */ modifyDataByPathIndex(updateData, pathIndex, dataIndex) { if (!updateData || !(updateData instanceof Array)) { throw ("更新数据格式不正确"); } console.log(updateData); let primaryKeyValue = undefined; let uniList = []; for (let updateJson of updateData) { let itemIndex = this.setJson.index[updateJson.name]; if (typeof itemIndex != "number") { throw ("未知列 " + updateJson.name); } let item = this.setJson.data[itemIndex]; if (item.primaryKey) { if (!updateJson.value) { throw ("主键 " + item.name + " 不能为空") } else { primaryKeyValue = updateJson.value; } } else if (item.uni) { if (typeof updateJson.value == "undefined") { throw ("唯一键 " + item.name + " 不能为空") } else { uniList.push({ name: item.name, value: updateJson.value }); } } if (updateJson.value && typeof updateJson.value != item.type) { throw ("字段 " + item.name + " 类型不匹配 " + item.type) } } this.checkSaveValue(primaryKeyValue, uniList); let modifyCount = 0; let dataJson = this.dataJsonList[pathIndex]; let curIndex = dataIndex; this.loadDataJson(dataJson); let targetValue = dataJson.data[dataIndex]; if (!targetValue || targetValue.__delete) { return modifyCount; } for (let updateJson of updateData) { let itemIndex = this.setJson.index[updateJson.name]; let setItem = this.setJson.data[itemIndex]; if (setItem.primaryKey) { delete dataJson.primaryKeyIndex[targetValue[setItem.name]]; dataJson.primaryKeyIndex[updateJson.value] = curIndex; } else if (setItem.uni) { delete dataJson.uniIndex[setItem.name][targetValue[setItem.name]]; dataJson.uniIndex[setItem.name][updateJson.value] = curIndex; } if (this.indexJsonMap[setItem.name]) { delete dataJson.indexMap[setItem.name][targetValue[setItem.name]]; if (dataJson.indexMap[setItem.name][updateJson.value] instanceof Array) { dataJson.indexMap[setItem.name][updateJson.value].push(curIndex); } else { dataJson.indexMap[setItem.name][updateJson.value] = [curIndex]; } } targetValue[updateJson.name] = updateJson.value; dataJson.data[dataIndex] = targetValue; } dataJson.modify = 1; modifyCount++; if (modifyCount > 0) { if (this.autoCommit) { this.commit(); } } return modifyCount; } deleteDataByPathIndex({pathIndex, dataIndex}) { if(typeof pathIndex != "number"){ throw("缺少参数pathIndex"); } if(typeof dataIndex != "number"){ throw("缺少参数dataIndex"); } let deleteCount = 0; this.checkConnect(); let dataJson = this.dataJsonList[pathIndex]; this.loadDataJson(dataJson); if (dataJson.data[dataIndex]) { let targetValue = dataJson.data[dataIndex]; for (let setItem of this.setJson.data) { if (setItem.primaryKey) { delete dataJson.primaryKeyIndex[targetValue[setItem.name]]; } else if (setItem.uni) { delete dataJson.uniIndex[setItem.name][targetValue[setItem.name]]; } if (this.indexJsonMap[setItem.name]) { let targetIndex = dataJson.indexMap[setItem.name][targetValue[setItem.name]].indexOf(curIndex); if (targetIndex > -1) { dataJson.indexMap[setItem.name][targetValue[setItem.name]].splice(targetIndex, 1); } } dataJson.data[dataIndex] = { __delete: 1 } } dataJson.modify = 1; deleteCount++; } if (dataJson.modify) { if (this.autoCommit) { this.commit(); } } return deleteCount; } /** * 删除数据 * @param {*} whereData {name:"列名",type:"比对类型",value:"值"} */ deleteData(whereData) { let deleteCount = 0; this.selectData(whereData, (dataJson, curIndex, targetValue) => { dataJson.data[curIndex] = { __delete: 1 }; dataJson.modify = 1; for (let setItem of this.setJson.data) { if (setItem.primaryKey) { delete dataJson.primaryKeyIndex[targetValue[setItem.name]]; } else if (setItem.uni) { delete dataJson.uniIndex[setItem.name][targetValue[setItem.name]]; } if (this.indexJsonMap[setItem.name]) { let targetIndex = dataJson.indexMap[setItem.name][targetValue[setItem.name]].indexOf(curIndex); if (targetIndex > -1) { dataJson.indexMap[setItem.name][targetValue[setItem.name]].splice(targetIndex, 1); } } } deleteCount++; }) if (deleteCount > 0) { if (this.autoCommit) { this.commit(); } } return deleteCount; } loadDataJson(dataJson) { if (!dataJson.read) { let { data, primaryKeyIndex, uniIndex, indexMap } = this.readDataJson(dataJson.path); dataJson.data = data; dataJson.primaryKeyIndex = primaryKeyIndex; dataJson.uniIndex = uniIndex; dataJson.read = 1; if (!indexMap) { indexMap = {}; } dataJson.indexMap = indexMap; let indexJsonMap = this.indexJsonMap; for (let key in indexJsonMap) { if (!indexMap[key]) { indexMap[key] = {}; let index = 0; for (let targetData in dataJson.data) { if (!(indexMap[key][targetData[key]] instanceof Array)) { indexMap[key][targetData[key]] = [] } indexMap[key][targetData[key]].push(index); index++; } dataJson.modify = 1; } } for (let key in indexMap) { if (!indexJsonMap[key]) { delete indexMap[key]; dataJson.modify = 1; } } } if (typeof dataJson.readCount != "number") { dataJson.readCount = 0; } dataJson.readCount++; if (dataJson.modify) { this.saveDataJson({ data: dataJson.data, path: dataJson.path, primaryKeyIndex: dataJson.primaryKeyIndex, uniIndex: dataJson.uniIndex, indexMap: dataJson.indexMap || {} }); } } /** * 查询数据 * @param {*} whereData [{name:"列名",type:"比对类型",value:"值"}] * @return 目前返回的都是对象，即实际是地址，不可以直接修改，需深拷贝后再直接修改，不然容易发生错误 */ selectData(whereData, mapFun, limitData, orderByData) { if (!(whereData instanceof Array)) { throw ("whereData必须为数组"); } this.checkConnect(); let resultSelect = []; let setJson = this.setJson; let { primaryKeyWhere, uniKeyWhere, indexKeyWhere, otherKeyWhere, primaryEqualKeyWhere, uniEqualKeyWhere, indexEqualKeyWhere } = this.parseWhereArray(whereData, setJson); for (let dataJson of this.dataJsonList) { this.loadDataJson(dataJson); this.filterAllWhere(dataJson, { primaryKeyWhere, indexKeyWhere, otherKeyWhere, uniKeyWhere, primaryEqualKeyWhere, uniEqualKeyWhere, mapFun, indexEqualKeyWhere }, resultSelect); if ((!orderByData || orderByData.length == 0) && limitData && typeof limitData.count == "number") { if (!limitData.start) { limitData.start = 0; } if (resultSelect.length > limitData.start + limitData.count) { resultSelect = resultSelect.slice(limitData.start, limitData.start + limitData.count); break; } } } if (orderByData && orderByData.length > 0) { resultSelect.sort((a, b) => { for (let orderby of orderByData) { if(a[orderby.name] != b[orderby.name]){ return orderby.type == "desc"?(b[orderby.name] - a[orderby.name]):(a[orderby.name] - b[orderby.name]); } } if(a.__pathIndex != b.__pathIndex){ return a.__pathIndex - b.__pathIndex; } return a.__index - b.__index; }); if (limitData && typeof limitData.count == "number") { if (!limitData.start) { limitData.start = 0; } resultSelect = resultSelect.slice(limitData.start, limitData.start + limitData.count); } } return resultSelect; } filterAllWhere(dataJson, { primaryKeyWhere, indexKeyWhere, indexEqualKeyWhere = [], otherKeyWhere, uniKeyWhere, primaryEqualKeyWhere, uniEqualKeyWhere, mapFun }, resultSelect) { if (primaryEqualKeyWhere.value) { let dataIndex = dataJson.primaryKeyIndex[primaryEqualKeyWhere.value]; if (typeof dataIndex == "number") { let targetValue = dataJson.data[dataIndex]; if (targetValue && !targetValue.__delete) { targetValue.__index = dataIndex; targetValue.__pathIndex = dataJson.pathIndex; if (this.checkValueWhere(targetValue, [...indexKeyWhere, ...indexEqualKeyWhere, ...uniKeyWhere, ...otherKeyWhere, ...primaryKeyWhere])) { resultSelect.push(targetValue); typeof mapFun == "function" && mapFun(dataJson, dataIndex, targetValue); } } } } else if (primaryKeyWhere.value) { let primaryKeyIndex = dataJson.primaryKeyIndex; let resultIndex = []; for (let value in primaryKeyIndex) { if (util.compare(value, primaryKeyWhere.type, primaryKeyWhere.value)) { resultIndex.push(primaryKeyWhere[value]); } } for (let dataIndex of resultIndex) { let targetValue = dataJson.data[dataIndex]; if (targetValue && !targetValue.__delete) { targetValue.__index = dataIndex; targetValue.__pathIndex = dataJson.pathIndex; if (this.checkValueWhere(targetValue, [...indexKeyWhere, ...indexEqualKeyWhere, ...uniKeyWhere, ...uniEqualKeyWhere, ...otherKeyWhere])) { resultSelect.push(targetValue); typeof mapFun == "function" && mapFun(dataJson, dataIndex, targetValue); } } } } else if (uniEqualKeyWhere.length > 0) { let uniArrayIndex = undefined; for (let uniWhere of uniEqualKeyWhere) { let curUniIndex = dataJson.uniIndex[uniWhere.name][uniWhere.value]; if (typeof curUniIndex != "number") { uniArrayIndex = undefined; break; } if (uniArrayIndex == undefined) { uniArrayIndex = curUniIndex; } else { if (uniArrayIndex != curUniIndex) { uniArrayIndex = undefined; break; } } } if (typeof uniArrayIndex == "number") { let targetValue = dataJson.data[uniArrayIndex]; if (targetValue && !targetValue.__delete) { targetValue.__index = uniArrayIndex; targetValue.__pathIndex = dataJson.pathIndex; if (this.checkValueWhere(targetValue, [...indexKeyWhere, ...indexEqualKeyWhere, ...uniKeyWhere, ...otherKeyWhere])) { resultSelect.push(targetValue); typeof mapFun == "function" && mapFun(dataJson, uniArrayIndex, targetValue); } } } } else if (uniKeyWhere.length > 0) { let uniArrayIndex = undefined; for (let uniWhere of uniKeyWhere) { let curUniIndex = dataJson.uniIndex[uniWhere.name]; if (typeof curUniIndex == "undefined" || curUniIndex.length == 0) { break; } let filterIndex = []; for (let value in curUniIndex) { if (util.compare(value, uniWhere.type, uniWhere.value)) { filterIndex.push(curUniIndex[value]); } } if (uniArrayIndex == undefined) { uniArrayIndex = filterIndex; continue; } else { uniArrayIndex = uniArrayIndex.filter(a => { return filterIndex.indexOf(a) >= 0; }) } if (uniArrayIndex.length == 0) { break; } } if (uniArrayIndex && uniArrayIndex.length > 0) { for (let index of uniArrayIndex) { let targetValue = dataJson.data[index]; if (targetValue && !targetValue.__delete) { targetValue.__index = index; targetValue.__pathIndex = dataJson.pathIndex; if (this.checkValueWhere(targetValue, [...indexEqualKeyWhere, ...indexKeyWhere, ...otherKeyWhere])) { resultSelect.push(targetValue); typeof mapFun == "function" && mapFun(dataJson, index, targetValue); } } } } } else if (indexEqualKeyWhere.length > 0) { let indexMap = dataJson.indexMap; let curIndexArray = undefined; for (let indexEqualKey of indexEqualKeyWhere) { if (!indexMap[indexEqualKey.name]) { continue; } if (!curIndexArray) { curIndexArray = indexMap[indexEqualKey.name][indexEqualKey.value] || []; } else { let filterIndex = indexMap[indexEqualKey.name][indexEqualKey.value] || []; curIndexArray = curIndexArray.filter(item => { return filterIndex.indexOf(item) > -1; }) } } if (curIndexArray && curIndexArray.length > 0) { for (let curIndex of curIndexArray) { let targetValue = dataJson.data[curIndex]; if (targetValue && !targetValue.__delete) { targetValue.__index = curIndex; targetValue.__pathIndex = dataJson.pathIndex; if (this.checkValueWhere(targetValue, [...indexKeyWhere, ...otherKeyWhere])) { resultSelect.push(targetValue); typeof mapFun == "function" && mapFun(dataJson, curIndex, targetValue); } } } } } else if (indexKeyWhere.length > 0) { let resultIndex = undefined; let indexMap = dataJson.indexMap; for (let indexkey of indexKeyWhere) { if (!indexMap[indexkey.name]) { continue; } let indexMapValue = indexMap[indexkey.name]; for (let indexValue in indexMapValue) { if (util.compare(indexValue, indexkey.type, indexkey.value)) { if (resultIndex == undefined) { resultIndex = indexMapValue[indexValue]; } else { resultIndex = resultIndex.filter(item => { return indexMapValue[indexValue].indexOf(item) > -1; }) if (resultIndex.length == 0) { resultIndex = []; break; } } } } } if (resultIndex == undefined) { //没有索引列，扫描全表 let curIndex = 0; for (let targetValue of dataJson.data) { if (targetValue && !targetValue.__delete) { targetValue.__index = curIndex; targetValue.__pathIndex = dataJson.pathIndex; if (this.checkValueWhere(targetValue, [...indexKeyWhere, ...otherKeyWhere])) { resultSelect.push(targetValue); typeof mapFun == "function" && mapFun(dataJson, curIndex, targetValue); } } curIndex++; } } else if (resultIndex.length > 0) { //有索引 扫描索引 for (let curIndex of resultIndex) { let targetValue = dataJson.data[curIndex]; if (targetValue && !targetValue.__delete) { targetValue.__index = curIndex; targetValue.__pathIndex = dataJson.pathIndex; if (this.checkValueWhere(targetValue, [...otherKeyWhere])) { resultSelect.push(targetValue); typeof mapFun == "function" && mapFun(dataJson, curIndex, targetValue); } } } } } else if (otherKeyWhere.length > 0) { let curIndex = 0; for (let targetValue of dataJson.data) { if (targetValue && !targetValue.__delete) { targetValue.__index = curIndex; targetValue.__pathIndex = dataJson.pathIndex; if (this.checkValueWhere(targetValue, [...otherKeyWhere])) { resultSelect.push(targetValue); typeof mapFun == "function" && mapFun(dataJson, curIndex, targetValue); } } curIndex++; } } else { let curIndex = 0; for (let targetValue of dataJson.data) { if (targetValue && !targetValue.__delete) { targetValue.__index = curIndex; targetValue.__pathIndex = dataJson.pathIndex; resultSelect.push(targetValue); typeof mapFun == "function" && mapFun(dataJson, curIndex, targetValue); } curIndex++; } } } checkValueWhere(value, whereArr) { let result = true; for (let item of whereArr) { if (!util.compare(value[item.name], item.type, item.value)) { result = false; break; } } return result; } /** * 添加数据 * @param {*} itemData 添加的数据 */ addData(itemData) { this.checkConnect(); let setData = this.setJson.data; if (!setData.autoIncrementIndex) { setData.autoIncrementIndex = {}; } let addJson = {}; let primaryKeyValue = undefined; let uniList = []; for (let item of setData) { if (item.primaryKey) { if (!itemData[item.name] && !item.autoIncrement) { throw ("主键 " + item.name + " 不能为空") } else if (!itemData[item.name]) { primaryKeyValue = (setData.autoIncrementIndex[item.name] || 0) + 1; setData.autoIncrementIndex[item.name] = primaryKeyValue; itemData[item.name] = primaryKeyValue; setData.modify = 1; } else { primaryKeyValue = itemData[item.name]; } } else if (item.uni) { if (!itemData[item.name]) { throw ("唯一键 " + item.name + " 不能为空") } else { uniList.push({ name: item.name, value: itemData[item.name] }); } } else if (item.autoIncrement && !itemData[item.name]) { itemData[item.name] = (setData.autoIncrementIndex[item.name] || 0) + 1; setData.autoIncrementIndex[item.name] = itemData[item.name]; setData.modify = 1; } if (itemData[item.name] && typeof itemData[item.name] != item.type) { throw ("字段 " + item.name + " 类型不匹配 " + item.type) } if (typeof itemData[item.name] != "undefined") { addJson[item.name] = itemData[item.name]; } else { addJson[item.name] = item.default; } } let curDataJson = this.getCurDataJson(); this.checkSaveValue(primaryKeyValue, uniList); curDataJson.data.push(addJson); let curAddIndex = curDataJson.data.length - 1; if (typeof primaryKeyValue != "undefined") { curDataJson.primaryKeyIndex[primaryKeyValue] = curAddIndex; } for (let uni of uniList) { if (!curDataJson.uniIndex[uni.name]) { curDataJson.uniIndex[uni.name] = {}; } if (typeof uni.value != "undefined") { curDataJson.uniIndex[uni.name][uni.value] = curAddIndex; } } let indexMap = curDataJson.indexMap; if (!indexMap) { curDataJson.indexMap = {}; indexMap = curDataJson.indexMap; } for (let indexName in indexMap) { if (indexMap[indexName]) { indexMap[indexName].push(curAddIndex); } } curDataJson.modify = 1; if (this.autoCommit) { this.commit(); if (this.setJson.modify == 1) { this.saveSetJson(); } } } /** * 检查主键和唯一键是否冲突 * @param {*} primaryKeyValue 主键 * @param {*} uniList 唯一键 {键名：值} */ checkSaveValue(primaryKeyValue, uniList) { if (!primaryKeyValue && !uniList) { return; } let dataJsonList = this.dataJsonList; for (let dataJson of dataJsonList) { this.loadDataJson(dataJson); if (typeof primaryKeyValue != "undefined" && typeof dataJson.primaryKeyIndex[primaryKeyValue] == "number") { throw ("主键 " + value + " 已存在，请勿重复添加") } if (uniList instanceof Array) { for (let uni of uniList) { if (dataJson.uniIndex[uni.name] && typeof dataJson.uniIndex[uni.name][uni.value] == "number") { throw ("唯一键 " + uni.name + " 值 " + uni.value + " 已存在，请勿重复添加") } } } if (!dataJson.readCount) { dataJson.readCount = 1; } else { dataJson.readCount++; } } } /** * 获取最新的数据对象 */ getCurDataJson() { if (this.dataJsonList.length == 0) { let curDataJson = { path: 'data_0.json', data: [], read: 1, modify: 0, primaryKeyIndex: {}, uniIndex: {} }; this.dataJsonList.push(curDataJson); return curDataJson; } let curDataJson = this.dataJsonList[this.dataJsonList.length - 1]; if (curDataJson.data.length >= MaxSaveLines) { let curIndex = this.dataJsonList.length; curDataJson = { path: 'data_' + curIndex + '.json', data: [], read: 1, modify: 0, primaryKeyIndex: {}, uniIndex: {} }; this.dataJsonList.push(curDataJson); } if (typeof curDataJson.readCount == "undefined") { curDataJson.readCount = 0; } curDataJson.readCount++; return curDataJson; } /** * 提交数据 */ commit() { this.checkConnect(); this.doSaveDataJson(); } /** * 数据回滚 不保存 */ rollback() { this.checkConnect(); this.reloadDataJson(); } /** * 重载内存数据 */ reloadDataJson() { let dataJsonList = this.dataJsonList; for (let dataJson of dataJsonList) { dataJson.read = 0; dataJson.modify = 0; dataJson.data = []; dataJson.readCount = 0; dataJson.indexMap = {}; } } /** * 释放最近不使用的内存数据 */ releaseDataJson() { let dataJsonList = this.dataJsonList; if (dataJsonList.length <= releaseSaveCount) { return; } if (releaseDataJsonTimeout) { clearTimeout(releaseDataJsonTimeout) } releaseDataJsonTimeout = setTimeout(() => { let readCountMap = []; let index = 0; for (let dataJson of dataJsonList) { if (dataJson.read && dataJson.modify) { index++; continue; } readCountMap.push({ path: dataJson.path, readCount: dataJson.readCount || 0, index: index }) index++; } readCountMap.sort((a, b) => { if (a.readCount == b.readCount) { return a.index - b.index; } return a.readCount - b.readCount; }) for (let readIndex = 0; readIndex < readCountMap.length - releaseSaveCount; readIndex++) { dataJsonList[readCountMap[readIndex].index].data = []; dataJsonList[readCountMap[readIndex].index].modify = 0; dataJsonList[readCountMap[readIndex].index].readCount = 0; dataJsonList[readCountMap[readIndex].index].read = 0; dataJsonList[readCountMap[readIndex].index].primaryKeyIndex = {}; dataJsonList[readCountMap[readIndex].index].uniIndex = {}; } }, releaseLimitTime); } /** index 相关操作开始 */ loadTableIndex() { this.checkConnect(); try { let { data } = this.readIndexJson(); this.indexJsonMap = data; } catch (e) { util.log(e); this.indexJsonMap = {}; this.saveIndexJson({ data: {} }); } } readIndexJson() { let result = this.readFileSync('/index/index.json', { data: {}, }); return result; } saveIndexJson(indexJson) { this.fileManmger.writeFileSync({ filePath: this.CurPath + "/index/index.json", data: JSON.stringify(indexJson), encoding: "utf-8" }) util.log("保存indexJson") } /** * 添加索引 */ alertAddIndex(name) { this.checkConnect(); if (typeof this.setJson.index[name] != "number") { throw ("不存在字段：" + name); } if (this.indexJsonMap[name]) { throw ("已存在索引：" + name); } else { this.indexJsonMap[name] = 1; } this.doSaveIndexJson(); } /** * 删除索引 */ dropIndex(name) { this.checkConnect(); if (typeof this.setJson.index[name] != "number") { throw ("不存在字段：" + name); } let curIndexJsonList = this.indexJsonMap[name]; if (typeof curIndexJsonList == "undefined") { throw ("不存在索引：" + name); } delete this.indexJsonMap[name]; } doSaveIndexJson() { if (saveIndexJsonTimeout) { clearTimeout(saveIndexJsonTimeout); } saveIndexJsonTimeout = setTimeout(() => { this.saveIndexJson({ data: this.indexJsonMap }); }, saveLimitTime); } /** index 相关操作结束 */ deleteFile(path) { this.fileManmger.unlinkSync({ filePath: path }) } parseWhereArray(whereData, setJson) { let primaryKeyWhere = {}; let primaryEqualKeyWhere = {}; let uniKeyWhere = []; let uniEqualKeyWhere = []; let indexKeyWhere = []; let otherKeyWhere = []; let indexEqualKeyWhere = []; for (let item of whereData) { if (typeof setJson.index[item.name] != "number") { throw ("不存在字段：" + item.name); } let curSetJson = setJson.data[setJson.index[item.name]]; if (curSetJson.primaryKey) { if (item.type == "=") { primaryEqualKeyWhere = item; } else { primaryKeyWhere = item; } } else if (curSetJson.uni) { if (item.type == "=") { uniEqualKeyWhere.push(item); } else { uniKeyWhere.push(item); } } else if (typeof this.indexJsonMap[item.name] != "undefined") { if (item.type == "=") { indexEqualKeyWhere.push(item); } else { indexKeyWhere.push(item); } } else { otherKeyWhere.push(item); } } return { primaryKeyWhere, uniKeyWhere, indexKeyWhere, otherKeyWhere, uniEqualKeyWhere, primaryEqualKeyWhere, indexEqualKeyWhere } } } export default Table;

好了，本次分享就到这里，梦辛工作室（let dream is completed）