Server.mjs

import express from "express";
import fs from "fs";
import bodyParser from "body-parser";
import mysql from "mysql";
import path from "path";
var app = express();
var connection = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "12345",
    port: "3306",
    database: "cooperatedocument",
    multipleStatements: true
});
var __dirname = path.resolve();
String.prototype.insert = function (index, content) {
    return this.slice(0, index - 1) + content + this.slice(index - 1);
};
Object.prototype.followSet = function (changeSet2) {
    changeSet2.action.forEach(step2 => {
        this.followChain(step2);
    });
};

Object.prototype.followChain = function (step2) {
    //this.action = this.action.map(i => 1);
    this.action = this.action.map(step1 => {
        var temp1, temp2;
        temp1 = followStep(step1, step2); //左
        temp2 = followStep(step2, step1); //右
        step1 = temp2;
        step2 = temp1;
        return step1;
    });
};
//传入两个元操作对象
function followStep(step1, step2) {
    if (step1 === null || step2 === null) {
        return step2;
    } else if (step1.type === "i" && step2.type === "i") {
        if (step1.index <= step2.index) {
            step2.index++;
        } else {}
        return step2;
    } else if (step1.type === "d" && step2.type === "d") {
        if (step1.index < step2.index) {
            step2.index--;
        } else if (step1.index > step2.index) {} else {
            step2 = null;
        }
        return step2;
    } else if (step1.type === "d" && step2.type === "i") {
        if (step1.index < step2.index) {
            step2.index--;
        } else {}
        return step2;
    } else if (step1.type === "i" && step2.type === "d") {
        if (step1.index <= step2.index) {
            step2.index++;
        } else {}
        return step2;
    }
}
//返回一个转化过 先step1 再step2 的元操作
function initText(name) {
    connection.connect();
    connection.query("show tables like '" + name + "' ;", function (
        error,
        result
    ) {
        if (error) throw error;
        var x = new Array();
        x[0] = new Object();
        if (result.length === 0) {
            fs.readFile("./" + name + ".txt", "utf-8", function (err, data) {
                x[0].version = 0;
                x[0].text = data;
                var createSql =
                    "CREATE TABLE `" +
                    name +
                    "` (`version`int NOT NULL,`text`text NULL,`changeset`text NULL) ;";
                connection.query(
                    createSql +
                    "insert into " +
                    name +
                    ' (version,text) values (0,"' +
                    data +
                    '");',
                    function (error, result) {
                        if (error) throw error;
                        console.log(result);
                    }
                );
            });
        } else {
            connection.query(
                "select * from " +
                name +
                " where version =(select max(version) from " +
                name +
                ");",
                function (error, result) {
                    x[0].version = result[0].version;
                    x[0].text = result[0].text;
                    x[0].changeSet = result[0].changeSet;
                }
            );
        }
        test = x;
    });
}
var name = "test1";
var test;

initText(name);
app.use(bodyParser.json());
app.listen(1109);
app.get("/", function (req, res) {
    res.sendFile(__dirname + "/index.html");
});
app.get("/test", function (req, res) {
    res.sendFile(__dirname + "/test.html");
});
app.get("/getText", function (req, res) {
    res.send(test[test.length - 1]);
});

function apply(base, changeSet) {
    changeSet.action.forEach(element => {
        if (element.type === "i") {
            if (element.content == null) {
                base = base.insert(element.index, "\n");
            } else {
                base = base.insert(element.index, element.content);
            }
        }
        if (element.type === "d") {
            base = base.slice(0, element.index) + base.slice(element.index + 1);
        }
    });
    console.log(base);
    return base;
}
app.post("/submit", function (req, res) {
    // fs.writeFile('name.txt', req.body.content, function (err) {
    //     if (err) {
    //         console.log(err);
    //     }
    // });.
    console.log(req.body);
    if (req.body.length != 0) {
        var i = req.body.version + 1;
        for (; i < test.length; i++) {
            req.body.followSet(test[i].changeSet);
        }

        var next = {
            version: test[test.length - 1].version + 1,
            text: apply(test[test.length - 1].text, req.body),
            changeSet: req.body
        };
        test.push(next);
        connection.query(
            "insert into " +
            name +
            " (version,text,changeset) values (" +
            next.version +
            ',"' +
            next.text +
            "\",'" +
            JSON.stringify(next.changeSet) +
            "');",
            function (error, result) {
                if (error) throw error;
                console.log(result);
            }
        );
        console.log(test);
    }
    res.send("ok");
});