/**
* Copyright (C) 2015-2016 Regents of the University of California.
* @author: Jeff Thompson <jefft0@remap.ucla.edu>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
* A copy of the GNU Lesser General Public License is in the file COPYING.
*/
// Don't require modules since this is meant for the browser, not Node.js.
/**
* IndexedDbProducerDb extends ProducerDb to implement storage of keys for the
* producer using the browser's IndexedDB service. It contains one table that
* maps time slots (to the nearest hour) to the content key created for that
* time slot.
* Create an IndexedDbProducerDb to use the given IndexedDB database name.
* @param {string} databaseName IndexedDB database name.
* @note This class is an experimental feature. The API may change.
* @constructor
*/
var IndexedDbProducerDb = function IndexedDbProducerDb(databaseName)
{
ProducerDb.call(this);
this.database = new Dexie(databaseName);
this.database.version(1).stores({
// "timeSlot" is the hour-based time slot as hours since Jan 1, 1970 UTC. // number
// "key" is the encoded key // Uint8Array
contentKeys: "timeSlot"
});
this.database.open();
};
IndexedDbProducerDb.prototype = new ProducerDb();
IndexedDbProducerDb.prototype.name = "IndexedDbProducerDb";
/**
* Check if a content key exists for the hour covering timeSlot.
* @param {number} timeSlot The time slot as milliseconds since Jan 1, 1970 UTC.
* @param {boolean} useSync (optional) If true then return a rejected promise
* since this only supports async code.
* @return {Promise} A promise that returns true if there is a content key for
* timeSlot (else false), or that is rejected with ProducerDb.Error for a
* database error.
*/
IndexedDbProducerDb.prototype.hasContentKeyPromise = function(timeSlot, useSync)
{
if (useSync)
return Promise.reject(new ProducerDb.Error(new Error
("IndexedDbProducerDb.hasContentKeyPromise is only supported for async")));
var fixedTimeSlot = ProducerDb.getFixedTimeSlot(timeSlot);
return this.database.contentKeys.get(fixedTimeSlot)
.then(function(contentKeysEntry) {
return Promise.resolve(contentKeysEntry != undefined);
})
.catch(function(ex) {
return Promise.reject(new ProducerDb.Error(new Error
("IndexedDbProducerDb.hasContentKeyPromise: Error: " + ex)));
});
};
/**
* Get the content key for the hour covering timeSlot.
* @param {number} timeSlot The time slot as milliseconds since Jan 1, 1970 UTC.
* @param {boolean} useSync (optional) If true then return a rejected promise
* since this only supports async code.
* @return {Promise} A promise that returns a Blob with the encoded key, or that
* is rejected with ProducerDb.Error if there is no key covering timeSlot, or
* other database error
*/
IndexedDbProducerDb.prototype.getContentKeyPromise = function(timeSlot, useSync)
{
if (useSync)
return Promise.reject(new ProducerDb.Error(new Error
("IndexedDbProducerDb.getContentKeyPromise is only supported for async")));
var fixedTimeSlot = ProducerDb.getFixedTimeSlot(timeSlot);
return this.database.contentKeys.get(fixedTimeSlot)
.then(function(contentKeysEntry) {
if (contentKeysEntry)
return Promise.resolve(new Blob(contentKeysEntry.key));
else
return Promise.reject(new ProducerDb.Error(new Error
("IndexedDbProducerDb.getContentKeyPromise: Cannot get the key from the database")));
}, function(ex) {
return Promise.reject(new ProducerDb.Error(new Error
("IndexedDbProducerDb.getContentKeyPromise: Error: " + ex)));
});
};
/**
* Add key as the content key for the hour covering timeSlot.
* @param {number} timeSlot The time slot as milliseconds since Jan 1, 1970 UTC.
* @param {Blob} key The encoded key.
* @param {boolean} useSync (optional) If true then return a rejected promise
* since this only supports async code.
* @return {Promise} A promise that fulfills when the key is added, or that
* is rejected with ProducerDb.Error if a key for the same hour already exists
* in the database, or other database error.
*/
IndexedDbProducerDb.prototype.addContentKeyPromise = function
(timeSlot, key, useSync)
{
if (useSync)
return Promise.reject(new ProducerDb.Error(new Error
("IndexedDbProducerDb.addContentKeyPromise is only supported for async")));
var fixedTimeSlot = ProducerDb.getFixedTimeSlot(timeSlot);
// Add rejects if the primary key already exists.
return this.database.contentKeys.add
({ timeSlot: fixedTimeSlot, key: key.buf() })
.catch(function(ex) {
return Promise.reject(new ProducerDb.Error(new Error
("IndexedDbProducerDb.addContentKeyPromise: Error: " + ex)));
});
};
/**
* Delete the content key for the hour covering timeSlot. If there is no key for
* the time slot, do nothing.
* @param {number} timeSlot The time slot as milliseconds since Jan 1, 1970 UTC.
* @param {boolean} useSync (optional) If true then return a rejected promise
* since this only supports async code.
* @return {Promise} A promise that fulfills when the key is deleted (or there
* is no such key), or that is rejected with ProducerDb.Error for a database
* error.
*/
IndexedDbProducerDb.prototype.deleteContentKeyPromise = function(timeSlot, useSync)
{
if (useSync)
return Promise.reject(new ProducerDb.Error(new Error
("IndexedDbProducerDb.deleteContentKeyPromise is only supported for async")));
var fixedTimeSlot = ProducerDb.getFixedTimeSlot(timeSlot);
return this.database.contentKeys.delete(fixedTimeSlot)
.catch(function(ex) {
return Promise.reject(new ProducerDb.Error(new Error
("IndexedDbProducerDb.deleteContentKeyPromise: Error: " + ex)));
});
};