node-sybase/dist/sybase/src/SybaseDB.js

sybasedb for node with pool and Multi DB

/*
 * @Author: Wuhao
 * @Email: kiwh77@126.com
 * @Date: 2017-09-30 10:04:45
 * @LastEditTime: 2019-12-09 10:50:58
 */
var spawn = require('child_process').spawn;
var JSONStream = require('JSONStream');
var fs = require("fs");

//FIXME: this is bad should be a way to expose this jar file in the npm package 
//so that it can be called properly from parent packages.
var PATH_TO_JAVA_BRIDGE1 = process.env.PWD + "/node_modules/node-sybase/dist/sybase/JavaSybaseLink/dist/JavaSybaseLink.jar";
var PATH_TO_JAVA_BRIDGE2 = __dirname + "/../JavaSybaseLink/dist/JavaSybaseLink.jar";

function Sybase (host, port, dbname, username, password, logTiming, pathToJavaBridge) {
    this.connected = false;
    this.host = host;
    this.port = port;
    this.dbname = dbname;
    this.username = username;
    this.password = password;
    this.logTiming = (logTiming == true);

    this.pathToJavaBridge = pathToJavaBridge;
    if (this.pathToJavaBridge === undefined) {
        if (fs.existsSync(PATH_TO_JAVA_BRIDGE1))
            this.pathToJavaBridge = PATH_TO_JAVA_BRIDGE1;
        else
            this.pathToJavaBridge = PATH_TO_JAVA_BRIDGE2;
    }

    this.queryCount = 0;
    this.currentMessages = {}; // look up msgId to message sent and call back details.

    this.jsonParser = JSONStream.parse();
}

Sybase.prototype.connect = function (callback) {
    var that = this;
    this.javaDB = spawn('java', ["-jar", this.pathToJavaBridge, this.host, this.port, this.dbname, this.username, this.password]);

    var hrstart = process.hrtime();
    this.javaDB.stdout.once("data", function (data) {
        if ((data + "").trim() != "connected") {
            callback(new Error("Error connecting " + data));
            return;
        }

        that.javaDB.stderr.removeAllListeners("data");
        that.connected = true;

        // set up normal listeners.		
        that.javaDB.stdout.setEncoding('utf8').pipe(that.jsonParser).on("data", function (jsonMsg) { that.onSQLResponse.call(that, jsonMsg); });
        that.javaDB.stderr.on("data", function (err) { that.onSQLError.call(that, err); });

        callback(null, data);
    });

    // handle connection issues.
    this.javaDB.stderr.once("data", function (data) {
        that.javaDB.stdout.removeAllListeners("data");
        that.javaDB.kill();
        callback(new Error(data));
    });
};

Sybase.prototype.disconnect = function () {
    this.javaDB.kill();
    this.connected = false;
}

Sybase.prototype.isConnected = function () {
    return this.connected;
};

Sybase.prototype.query = function (sql, callback) {
    if (this.isConnected === false) {
        callback(new Error("database isn't connected."));
        return;
    }
    var hrstart = process.hrtime();
    this.queryCount++;

    var msg = {};
    msg.msgId = this.queryCount;
    msg.sql = sql;
    msg.sentTime = (new Date()).getTime();
    var strMsg = JSON.stringify(msg).replace(/[\n]/g, '\\n');
    msg.callback = callback;
    msg.hrstart = hrstart;

    console.log("this: " + this + " currentMessages: " + this.currentMessages + " this.queryCount: " + this.queryCount);

    this.currentMessages[msg.msgId] = msg;

    this.javaDB.stdin.write(strMsg + "\n");
    console.log("sql request written: " + strMsg);
};

Sybase.prototype.onSQLResponse = function (jsonMsg) {
    var err = null;
    var request = this.currentMessages[jsonMsg.msgId];
    delete this.currentMessages[jsonMsg.msgId];

    var result = jsonMsg.result;
    if (result.length === 1)
        result = result[0]; //if there is only one just return the first RS not a set of RS's

    var currentTime = (new Date()).getTime();
    var sendTimeMS = currentTime - jsonMsg.javaEndTime;
    hrend = process.hrtime(request.hrstart);
    var javaDuration = (jsonMsg.javaEndTime - jsonMsg.javaStartTime);

    if (jsonMsg.error !== undefined)
        err = new Error(jsonMsg.error);


    if (this.logTiming)
        console.log("Execution time (hr): %ds %dms dbTime: %dms dbSendTime: %d sql=%s", hrend[0], hrend[1] / 1000000, javaDuration, sendTimeMS, request.sql);
    request.callback(err, result);
};
// 处理连接关闭 JZ006: 捕获到 IO 例外:com.sybase.jdbc3.jdbc.SybConnectionDeadException: JZ0C0: 连接已关闭。
Sybase.prototype.onSQLError = function (data) {
    var error = new Error(data);

    var callBackFuncitons = [];
    for (var k in this.currentMessages) {
        if (this.currentMessages.hasOwnProperty(k)) {
            callBackFuncitons.push(this.currentMessages[k].callback);
        }
    }

    // clear the current messages before calling back with the error.
    this.currentMessages = [];
    callBackFuncitons.forEach(function (cb) {
        cb(error);
    });
};

module.exports = Sybase;