sqlite-proxy/sqlite_proxy.js

Proxy for sqlite3

var net = require('net');

function splitMergedJSON(data) {
 return data.split('}{').map(function (item,index,arr) {
  return (index ? '{' : '') + item + (index==arr.length-1 ? '' : '}');
 });
}


module.exports.Server = function(path,cb) {
 var sqlite3= require('sqlite3');
 var db = new sqlite3.Database(path);
 var net = require('net');
 var randport = require('randport');
 
 randport(function(error,port) {
  if(error && cb) {
   return cb(error);
  }
  net.createServer(function(socket) {
   socket.on('data',function(data) {
    splitMergedJSON(data.toString()).forEach(function(data) {
     data = JSON.parse(data.toString());
		   var args=data.msg;
		   function sendback (error) {
		    if(error) {
		     console.log(error);
		    }
		    var sending = JSON.stringify(
		     {mark:data.mark,
		      context:{lastID:this.lastID},
		      msg:arguments});
		    console.log('sending:',sending);
		    socket.write(sending);
		   }
		   args.push(sendback);
		   console.log('action:',data.action);
		   sqlite3.Database.prototype[data.action].apply(db,args);
		  });
		 });
  }).listen(port);
  if(cb) {
   cb(null,port);
  }
  else {
   console.log(port);
  }
 });
};

var cbs = {};
function Client(port) {
 
 this.socket = net.connect({port:port});
 this.socket.on('data',function(data) {
  var data=data.toString();
  console.log('json:',data);
  splitMergedJSON(data).forEach(function(data) {
		 data=JSON.parse(data);
		 var args=require('lodash').valuesIn(data.msg);
		 console.log('cb mark:',data.mark,args);
		 cbs[data.mark].apply(data.context,args);
		 process.nextTick(function () {
		  //delete cbs[data.mark];
		 });
		});
 });
}

var querycount=0;

Client.prototype.run = function () {
 if(arguments < 3) {
  throw 'Insufficent arguments';
 }
 var args=Array.prototype.slice.call(arguments);
 var action = args.shift();
 var cb=args.pop();
 var id = ++querycount;
 cbs[id] = cb;
 this.socket.write(JSON.stringify({mark:id,action:action,msg:args}));
};

Client.prototype.query = function () {
 if(arguments.length < 2) {
  throw 'Insufficent arguments';
 }
 var args = Array.prototype.slice.call(arguments);
 var cb = args.pop();
 var id = ++querycount;
 cbs[id]=cb;
 this.socket.write(JSON.stringify({mark:id,action:'all',msg:args}));
};

module.exports.Client = Client;


module.exports.launchProxy = function(path,cb) {
 console.log('hi');
 var client;
 var n=require('child_process').spawn('node',['-e','require("sqlite-proxy").Server("'+path+'")']);
 n.stdout.on('data',function(data) {
  console.log('sql-server:',data.toString());
  if(!client) {
		 var port=parseInt(data.toString().split('\n')[0]);
		 if(port) {
		  client=new Client(port);
		  cb(null,client);
		 }
		}
 });
 n.stderr.on('data',function(data) {
  console.log('sql-server-error:',data.toString());
 });
 process.on('exit',function () {
  n.kill();
 });
};