pg atomic transaction test 2

transact2.js

var pg = require('pg'),
    path = require('path'),
    Query = require(path.join(path.dirname(require.resolve('pg')), 'query'));

pg.Client.prototype.next = function (config, values, callback) {
  //can take in strings or config objects
  config = (typeof(config) == 'string') ? { text: config } : config;
  if (this.binary && !('binary' in config)) {
    config.binary = true;
  }

  if(values) {
    if(typeof values === 'function') {
      callback = values;
    } else {
      config.values = values;
    }
  }

  config.callback = callback;

  var query = new Query(config);
  this.queryQueue.unshift(query);
  this._pulseQueryQueue();
  return query;
};

var client = new pg.Client('pg://user:[email protected]/postgres');

client.connect(function () {
  client.query('CREATE TEMP TABLE foo (bar real)', function () {
    for (var i = 0; i < 5; i++)
      insertRandomNumber();
  });
  client.once('drain', function () {
    client.query('SELECT bar FROM foo', function (err, results) {
      for (var i = 0; i < results.rowCount; i++)
        console.log(results.rows[i].bar);
    });
    client.once('drain', client.end.bind(client));
  });
});

function insertRandomNumber() {
  console.log('BEGIN');
  client.query('BEGIN', function () {
    console.log('INSERT');
    client.next('INSERT INTO foo VALUES (random()) RETURNING bar', function (err, result) {
      if (result.rows[0].bar < 0.5)
        console.log('COMMIT'), client.next('COMMIT');
      else
        console.log('ROLLBACK'), client.next('ROLLBACK');
    });
  });
}

Outputs the expected:

c:\node>node transact2
BEGIN
BEGIN
BEGIN
BEGIN
BEGIN
INSERT
COMMIT
INSERT
COMMIT
INSERT
ROLLBACK
INSERT
COMMIT
INSERT
COMMIT
0.0438101
0.187328
0.403612
0.16835