nosqldb-oraclejs/examples/ttl.js

Oracle NoSQL Database JS Driver

/*-
 *
 *  This file is part of Oracle NoSQL Database
 *  Copyright (C) 2014, 2018 Oracle and/or its affiliates.  All rights reserved.
 *
 * If you have received this file as part of Oracle NoSQL Database the
 * following applies to the work as a whole:
 *
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 *   General Public License as published by the Free Software Foundation,
 *   version 3.
 *
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 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *   Affero General Public License for more details.
 *
 * If you have received this file as part of Oracle NoSQL Database Client or
 * distributed separately the following applies:
 *
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 *   redistribute it and/or modify it under the terms of the Apache License
 *   as published by the Apache Software Foundation, version 2.0.
 *
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 *
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'use strict';

/**
 * This example demonstrates usage of Time-to-Live (TTL) feature of the 
 * Oracle NoSQL Database JS API.
 * 
 * The example:
 * - Creates a table.
 * - Puts a row in the table with a TTL value.
 * - Gets the row from the table and prints the row with its TTL value.
 */

// Include nosqldb-oraclejs module
var nosqldb = require('nosqldb-oraclejs');
var Types = nosqldb.Types;

// Create a configuration object
var configuration = new nosqldb.Configuration();
configuration.proxy.startProxy = true;
configuration.proxy.host = 'localhost:5010';
configuration.storeHelperHosts = ['localhost:5000'];
configuration.storeName = 'kvstore';

// Set a writeOptions object:
var writeOptions =
  new Types.WriteOptions(
    new Types.Durability(
      Types.SyncPolicy.NO_SYNC,
      Types.ReplicaAckPolicy.ALL,
      Types.SyncPolicy.NO_SYNC),
    1000);
// Set a readOptions object:
var readOptions =
  new Types.ReadOptions(
    Types.SimpleConsistency.NONE_REQUIRED,
    1000);


// Create a store with the specified configuration
var store = nosqldb.createStore(configuration);

var TABLE_NAME = 'ttl_table';

store.open(function (err) {
  if (err)
    throw err;

  console.log('Connected to the store: ' +
              configuration.storeName + ' at ' +
              configuration.storeHelperHosts);

  // Create a table
  store.execute(' CREATE TABLE IF NOT EXISTS ' + TABLE_NAME +
                ' ( id long, name string, PRIMARY KEY(id) ) ', function (err) {
    if (err) return;

    store.refreshTables(function (err) {
      if (err) return;

      console.log('Created table ' + TABLE_NAME);

      var row = {id: 1, name: 'John Doe'};
      // set updateTTL on WriteOptions
      writeOptions.updateTTL = true;
      console.log('Inserting row with TTL: ' + util.inspect(row));
      row.ttl = new Types.TimeToLive(42, Types.TimeUnit.HOURS);
      store.put(TABLE_NAME, row, writeOptions,
        function (err) {
          if (err)
            throw err;
          else {
            // This is the primary key
            var pKey = {id: 1};

            store.get(TABLE_NAME, pKey, readOptions,
              function (error, result) {
                console.log('Read row: ' + util.inspect(result.currentRow));
                console.log('Expiration (UTC) time: ' + result.expirationTime
                        + ' (' + toTTL(result.expirationTime) + ' from now)');
                // closing...
                store.close(function () {
                  console.log('Store closed, shutting down KVProxy...');
                  store.shutdownProxy(function (err) {
                    if (err)
                      throw err;
                    console.log('KVProxy off.')
                  }); // Shutdown
                }); // Close
              }); //Get
          }
        }); // Put
    }); // RefreshTables
  }); // Execute
});

function toTTL(utc) {
    var duration = (utc - new Date().getTime())/1000;
    var hours = ~~(duration/(60*60));
    var days = ~~(hours/24);
    hours = hours%24;
    hours = hours + ' hour' + (hours > 1 ? 's' : '');
    days  = (days > 0 ? days + ' day' : '') +  (days > 1 ? 's ' : ' ');
    return  days + hours; 
}