sybase-devdiniz/src/SybaseDB.js

A simple node.js wrapper around a java/jconnect app that provides easy access to Sybase Databases without having to install odbc or freetds.

// src/SybaseDB.js
var spawn = require('child_process').spawn;
var JSONStream = require('JSONStream');
var fs = require("fs");
var path = require("path");

function Sybase(host, port, dbname, username, password, logTiming, pathToJavaBridge, { encoding = "utf8", extraLogs = false, ...options } = {}) {
    this.connected = false;
    this.host = host;
    this.port = port;
    this.dbname = dbname;
    this.username = username;
    this.password = password;    
    this.logTiming = (logTiming === true);
    this.encoding = encoding;
    this.extraLogs = extraLogs;
    this.options = options; // Propriedades adicionais para o Java

    this.pathToJavaBridge = pathToJavaBridge;
    if (this.pathToJavaBridge === undefined) {
        this.pathToJavaBridge = path.resolve(__dirname, "..", "JavaSybaseLink", "dist", "JavaSybaseLink.jar");
    }

    this.queryCount = 0;
    this.currentMessages = {}; // lookup msgId to message sent and callback details.
    this.jsonParser = JSONStream.parse();
}

Sybase.prototype.log = function(msg) {
    if (this.extraLogs) {
        console.log(msg);
    }
};

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

    // Adiciona propriedades adicionais no formato CHAVE=VALOR, se houver
    if (this.options) {
        for (var key in this.options) {
            if (this.options.hasOwnProperty(key)) {
                args.push(key + "=" + this.options[key]);
            }
        }
    }

    this.javaDB = spawn('java', args);

    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;

        that.javaDB.stdout.setEncoding(that.encoding)
            .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);
    });

    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()) {
        callback(new Error("database isn't connected."));
        return;
    }    
    var hrstart = process.hrtime();
    this.queryCount++;
    
    var msg = {
        msgId: this.queryCount,
        sql: sql,
        sentTime: (new Date()).getTime(),
        callback: callback,
        hrstart: hrstart
    };

    this.currentMessages[msg.msgId] = msg;
    var strMsg = JSON.stringify(msg).replace(/[\n]/g, '\\n');
    this.javaDB.stdin.write(strMsg + "\n");
    this.log("sql request written: " + strMsg);
};

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

    var result = jsonMsg.result;
    if (result.length === 1)
        result = result[0];

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

    var err = (jsonMsg.error !== undefined) ? new Error(jsonMsg.error) : null;

    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);
};

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);
        }
    }
    this.currentMessages = [];
    callBackFuncitons.forEach(function(cb) {
        cb(error);
    });
};

module.exports = Sybase;