aws-commons/lib/S3ObjectList.js

A collection of small utilities to manage AWS services and actions

/**
 * @class S3ObjectList
 * @classdesc List all or a filtered set of objects for the specified S3 bucket. List with or without
 * details such as
 *
 * @author: darryl.west@raincity.com
 * @created: 4/27/14 2:20 PM
 */
var events = require('events'),
    util = require('util' ),
    dash = require('lodash');

var S3ObjectList = function(options) {
    'use strict';

    var lister = this,
        log = options.log,
        s3 = options.s3,
        bucket = options.bucket,
        prefix = options.prefix,
        maxKeys = dash.isNumber( options.maxKeys ) ? options.maxKeys : 1000,
        marker = options.marker;

    this.listCompleteCallback = function(err, data) {
        if (err) {
            lister.emit( 'error', err );
        } else {
            var results = {
                bucket:data.Name,
                maxKeys:data.MaxKeys,
                marker:data.Marker,
                isTruncated:data.IsTruncated,
                prefix:data.Prefix,
                list:[]
            };

            data.Contents.forEach(function(obj) {
                var item = {
                    key:obj.Key,
                    etag:obj.ETag,
                    lastModified:obj.LastModified,
                    size:obj.Size
                };

                results.list.push( item );
            });

            log.info('items: ', results.list.length);

            lister.emit( 'complete', results );
        }
    };

    this.list = function() {
        var params = {};

        params.Bucket = bucket;
        params.MaxKeys = maxKeys;

        if (prefix) {
            params.Prefix = prefix;
        }

        if (marker) {
            params.Marker = marker;
        }

        log.info('list objects in ', bucket, ' with params: ', params);

        return s3.listObjects( params, lister.listCompleteCallback );
    };

    this.setBucket = function(name) {
        bucket = name;
    };

    this.setMaxKeys = function(max) {
        maxKeys = max;
    };

    this.setPrefix = function(pfx) {
        prefix = pfx;
    };

    this.setMarker = function(name) {
        marker = name;
    };

    // constructor validations
    if (!log) throw new Error('lister must be constructed with a log');
    if (!s3) throw new Error('lister must be constructed with an S3 object');

    events.EventEmitter.call( this );
};

util.inherits( S3ObjectList, events.EventEmitter );

module.exports = S3ObjectList;