etherpad-lite/node/db/ReadOnlyManager.js

86 lines
2.2 KiB
JavaScript

/**
* The ReadOnlyManager manages the database and rendering releated to read only pads
*/
/*
* 2011 Peter 'Pita' Martischka
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS-IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var db = require("./DB").db;
var async = require("async");
/**
* returns a read only id for a pad
* @param {String} padId the id of the pad
*/
exports.getReadOnlyId = function (padId, callback)
{
var readOnlyId;
async.waterfall([
//check if there is a pad2readonly entry
function(callback)
{
db.get("pad2readonly:" + padId, callback);
},
function(dbReadOnlyId, callback)
{
//there is no readOnly Entry in the database, let's create one
if(dbReadOnlyId == null)
{
readOnlyId = "r." + randomString(16);
db.set("pad2readonly:" + padId, readOnlyId);
db.set("readonly2pad:" + readOnlyId, padId);
}
//there is a readOnly Entry in the database, let's take this one
else
{
readOnlyId = dbReadOnlyId;
}
callback();
}
], function(err)
{
//return the results
callback(err, readOnlyId);
})
}
/**
* returns a the padId for a read only id
* @param {String} readOnlyId read only id
*/
exports.getPadId = function(readOnlyId, callback)
{
db.get("readonly2pad:" + readOnlyId, callback);
}
/**
* Generates a random String with the given length. Is needed to generate the read only ids
*/
function randomString(len)
{
var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
var randomstring = '';
for (var i = 0; i < len; i++)
{
var rnum = Math.floor(Math.random() * chars.length);
randomstring += chars.substring(rnum, rnum + 1);
}
return randomstring;
}